Science.gov

Sample records for addition time spent

  1. Depression Common After Time Spent in ICU

    MedlinePlus

    ... gov/news/fullstory_160482.html Depression Common After Time Spent in ICU About one-third of ICU ... among former ICU patients are three to four times higher than in the general population, according to ...

  2. How Time Is Spent in Elementary Classrooms

    ERIC Educational Resources Information Center

    Rosenshine, Barak V.

    2015-01-01

    The Beginning Teacher Evaluation Study (BTES) provides valuable information on how time is spent in elementary classrooms. Some of the major topics are: the average minutes per day which students spend engaged in reading and math activities, student engagement rates in different settings (that is, teacher-led settings versus seatwork) and…

  3. 5 CFR 551.425 - Time spent receiving medical attention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Time spent receiving medical attention... Relation to Other Activities § 551.425 Time spent receiving medical attention. (a) Time spent waiting for and receiving medical attention for illness or injury shall be considered hours of work if: (1)...

  4. 5 CFR 551.425 - Time spent receiving medical attention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Time spent receiving medical attention... Relation to Other Activities § 551.425 Time spent receiving medical attention. (a) Time spent waiting for and receiving medical attention for illness or injury shall be considered hours of work if: (1)...

  5. 5 CFR 551.425 - Time spent receiving medical attention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Time spent receiving medical attention... Relation to Other Activities § 551.425 Time spent receiving medical attention. (a) Time spent waiting for and receiving medical attention for illness or injury shall be considered hours of work if: (1)...

  6. 5 CFR 551.425 - Time spent receiving medical attention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Time spent receiving medical attention... Relation to Other Activities § 551.425 Time spent receiving medical attention. (a) Time spent waiting for and receiving medical attention for illness or injury shall be considered hours of work if: (1)...

  7. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Time spent traveling. 551.422 Section 551.422 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work Application of Principles in Relation to Other Activities § 551.422 Time spent traveling....

  8. Adolescent Depression and Time Spent with Parents and Siblings

    ERIC Educational Resources Information Center

    Desha, Laura N.; Nicholson, Jan M.; Ziviani, Jenny M.

    2011-01-01

    This study examines adolescent depressive symptoms and the quantity and quality of time spent by adolescents with their parents and siblings. We use measures of the quality of relationships with parents and siblings as proxy indicators for the quality of time spent with these social partners. The study emphasizes the salience of parent…

  9. Do Workplace Flexibility Policies Influence Time Spent in Domestic Labor?

    ERIC Educational Resources Information Center

    Noonan, Mary C.; Estes, Sarah Beth; Glass, Jennifer L.

    2007-01-01

    Using data from a U.S. midwestern sample of mothers and fathers, the authors examine whether using workplace flexibility policies alters time spent in housework and child care. They hypothesize that an individual's policy use will lead to more time in domestic labor and that his or her spouse's policy use will lead to less time in domestic labor.…

  10. Time Spent Eating and Its Implications for Americans' Energy Balance

    ERIC Educational Resources Information Center

    Zick, Cathleen D.; Stevens, Robert B.

    2011-01-01

    The upward trend in Americans' weight has precipitated research aimed at identifying its underlying causes. In this paper we examine trends in Americans' time spent eating in an attempt to gain a better understanding of Americans' changing eating habits and their predictors. Data used in the analyses come from four national time use surveys…

  11. 5 CFR 551.426 - Time spent in charitable activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Time spent in charitable activities. 551.426 Section 551.426 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work Application of Principles...

  12. 5 CFR 551.425 - Time spent receiving medical attention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Time spent receiving medical attention. 551.425 Section 551.425 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work Application of Principles...

  13. High-Ability Students' Time Spent outside the Classroom

    ERIC Educational Resources Information Center

    Makel, Matthew C.; Li, Yan; Putallaz, Martha; Wai, Jonathan

    2011-01-01

    This study considered how three groups of academically talented high school students--those who attended an academic summer program (TIP), those who qualified for the program but chose not to attend (QNA), and those who did not qualify (DNQ)--spent time outside the classroom. These groupings differentiated students by ability (QNA vs. DNQ) and…

  14. Time Spent on the Internet and Adolescent Blood Pressure

    ERIC Educational Resources Information Center

    Cassidy-Bushrow, Andrea E.; Johnson, Dayna A.; Peters, Rosalind M.; Burmeister, Charlotte; Joseph, Christine L. M.

    2015-01-01

    Internet use is nearly ubiquitous among adolescents. Growing evidence suggests heavy Internet use negatively impacts health, yet the relationship between time spent on the Internet and adolescent blood pressure (BP) is unknown. We examined the association between Internet use and elevated BP in a racially diverse cross-sectional sample of 331…

  15. Use of electronic clinical documentation: time spent and team interactions

    PubMed Central

    Vawdrey, David K; Fred, Matthew R; Bostwick, Susan B

    2011-01-01

    Objective To measure the time spent authoring and viewing documentation and to study patterns of usage in healthcare practice. Design Audit logs for an electronic health record were used to calculate rates, and social network analysis was applied to ascertain usage patterns. Subjects comprised all care providers at an urban academic medical center who authored or viewed electronic documentation. Measurement Rate and time of authoring and viewing clinical documentation, and associations among users were measured. Results Users spent 20–103 min per day authoring notes and 7–56 min per day viewing notes, with physicians spending less than 90 min per day total. About 16% of attendings' notes, 8% of residents' notes, and 38% of nurses' notes went unread by other users, and, overall, 16% of notes were never read by anyone. Viewing of notes dropped quickly with the age of the note, but notes were read at a low but measurable rate, even after 2 years. Most healthcare teams (77%) included a nurse, an attending, and a resident, and those three users' groups were the first to write notes during an admission. Limitations The limitations were restriction to a single academic medical center and use of log files without direct observation. Conclusions Care providers spend a significant amount of time viewing and authoring notes. Many notes are never read, and rates of usage vary significantly by author and viewer. While the rate of viewing a note drops quickly with its age, even after 2 years inpatient notes are still viewed. PMID:21292706

  16. Achievement as a Function of Time Spent in Learning and Time Needed for Learning.

    ERIC Educational Resources Information Center

    Gettinger, Maribeth

    1984-01-01

    The causal effects of time spent in learning (TSL) and time needed for learning (TTL) on the reading and spelling achievement of 171 fourth and fifth grade students were investigated. TTL contributed significantly to achievement, and its direct effect was greater than TSL. Results also support a Carroll's learning model. (Author/BS)

  17. Time Spent on the Internet and Adolescent Blood Pressure.

    PubMed

    Cassidy-Bushrow, Andrea E; Johnson, Dayna A; Peters, Rosalind M; Burmeister, Charlotte; Joseph, Christine L M

    2015-10-01

    Internet use is nearly ubiquitous among adolescents. Growing evidence suggests heavy Internet use negatively impacts health, yet the relationship between time spent on the Internet and adolescent blood pressure (BP) is unknown. We examined the association between Internet use and elevated BP in a racially diverse cross-sectional sample of 331 healthy adolescents (ages 14-17 years). Heavy Internet use was defined as ≥ 2 hr/day, moderate use as <2 hr/day and ≥ 5 days/week, and light use as < 2 hr/day and ≤ 4 days/week. Elevated BP was defined as systolic or diastolic BP ≥ 90 th percentile. Heavy Internet users had statistically significantly higher odds of elevated BP compared to light Internet users. School nurses can play an important role in preventing high BP through assessment of BP and other health behaviors including Internet use, and health teaching to individuals, student groups, faculty, and parents to increase awareness of the relationship between Internet use and health. PMID:25377931

  18. Teacher Time Spent on Student Health Issues and School Nurse Presence

    ERIC Educational Resources Information Center

    Hill, Nina Jean; Hollis, Marianne

    2012-01-01

    Elementary school teacher time spent on student health issues and the relationship to school nurse services was the focus of this 2-year study. A cross-sectional design was used to survey traditional and exceptional (special needs) classroom teachers about the time they spent on health issues and their perception of school nurse presence. The…

  19. The Effect of Time Spent Online on Student Achievement in Online Economics and Finance Courses

    ERIC Educational Resources Information Center

    Calafiore, Pablo; Damianov, Damian S.

    2011-01-01

    This article studies the determinants of academic achievement in online courses in economics and finance. The authors use the online tracking feature in Blackboard (Campus Edition) to retrieve the real time that each student spent in the course for the entire semester and to analyze the impact of time spent online, prior grade point average (GPA),…

  20. Time Spent on Homework, Mathematics Anxiety and Mathematics Achievement: Evidence from a US Sample

    ERIC Educational Resources Information Center

    Cheema, Jehanzeb R.; Sheridan, Kimberly

    2015-01-01

    This study investigated the effect of time spent on homework and mathematics anxiety on mathematics achievement. Data from a nationally representative US sample consisting of 4,978 cases was used to predict mathematics achievement from time spent on homework and mathematics anxiety while controlling for demographic differences such as gender,…

  1. 48 CFR 852.271-72 - Time spent by counselee in counseling process.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... counseling process. 852.271-72 Section 852.271-72 Federal Acquisition Regulations System DEPARTMENT OF... Clauses 852.271-72 Time spent by counselee in counseling process. As prescribed in 871.212, insert the following clause: Time Spent by Counselee in Counseling Process (APR 1984) The contractor agrees that...

  2. Unobtrusive in-home detection of time spent out-of-home with applications to loneliness and physical activity

    PubMed Central

    Austin, Daniel; Kaye, Jeffrey A.; Pavel, Misha; Hayes, Tamara L.

    2014-01-01

    Loneliness is a common condition in elderly associated with severe health consequences including increased mortality, decreased cognitive function, and poor quality of life. Identifying and assisting lonely individuals is therefore increasingly important—especially in the home setting—as the very nature of loneliness often makes it difficult to detect by traditional methods. One critical component in assessing loneliness unobtrusively is to measure time spent out-of-home, as loneliness often presents with decreased physical activity, decreased motor functioning, and a decline in activities of daily living, all of which may cause decreases in the amount of time spent outside the home. Using passive and unobtrusive in-home sensing technologies, we have developed a methodology for detecting time spent out-of-home based on logistic regression. Our approach was both sensitive (0.939) and specific (0.975) in detecting time out-of-home across over 41,000 epochs of data collected from 4 subjects monitored for at least 30 days each in their own homes. In addition to linking time spent out-of-home to loneliness (r=−0.44, p=0.011) as measured by the UCLA Loneliness Index, we demonstrate its usefulness in other applications such as uncovering general behavioral patterns of elderly and exploring the link between time spent out-of-home and physical activity (r=0.415, p=0.031), as measured by the Berkman Social Disengagement Index. PMID:25192570

  3. Unobtrusive in-home detection of time spent out-of-home with applications to loneliness and physical activity.

    PubMed

    Petersen, Johanna; Austin, Daniel; Kaye, Jeffrey A; Pavel, Misha; Hayes, Tamara L

    2014-09-01

    Loneliness is a common condition in elderly associated with severe health consequences including increased mortality, decreased cognitive function, and poor quality of life. Identifying and assisting lonely individuals is therefore increasingly important-especially in the home setting-as the very nature of loneliness often makes it difficult to detect by traditional methods. One critical component in assessing loneliness unobtrusively is to measure time spent out-of-home, as loneliness often presents with decreased physical activity, decreased motor functioning, and a decline in activities of daily living, all of which may cause decrease in the amount of time spent outside the home. Using passive and unobtrusive in-home sensing technologies, we have developed a methodology for detecting time spent out-of-home based on logistic regression. Our approach was both sensitive (0.939) and specific (0.975) in detecting time out-of-home across over 41,000 epochs of data collected from four subjects monitored for at least 30 days each in their own homes. In addition to linking time spent out-of-home to loneliness, (r = -0.44, p = 0.011) as measured by the UCLA Loneliness Index, we demonstrate its usefulness in other applications such as uncovering general behavioral patterns of elderly and exploring the link between time spent out-of-home and physical activity ( r = 0.415, p = 0.031), as measured by the Berkman Social Disengagement Index. PMID:25192570

  4. Opinions of Teachers and Parents about Time Spent by Students at School, Lesson Hours, Break Times, Holidays and School Terms

    ERIC Educational Resources Information Center

    Gokce, Feyyat

    2012-01-01

    Amount of time spent at school is one of the mostly discussed educational matters. The present study was carried out to put forward the relationship between the time spent at school and learning acquisitions. In the study, 52 parents living in Bursa and 59 teachers were asked for their opinions. According to the data, while nearly half of the…

  5. Could Lots of Time Spent on Social Media Be Tied to Depression?

    MedlinePlus

    ... 157953.html Could Lots of Time Spent on Social Media Be Tied to Depression? Study did not prove ... The more time young adults spend using popular social media, the greater the link to depression, new research ...

  6. Estimation of sensitivity depending on sojourn time and time spent in preclinical state.

    PubMed

    Kim, Seongho; Wu, Dongfeng

    2016-04-01

    The probability model for periodic screening was extended to provide statistical inference for sensitivity depending on sojourn time, in which the sensitivity was modeled as a function of time spent in the preclinical state and the sojourn time. The likelihood function with the proposed sensitivity model was then evaluated with simulated data to check its reliability in terms of the mean estimation and the standard error. Simulation results showed that the maximum likelihood estimates of the proposed model have little bias and small standard errors. The extended probability model was further applied to the Johns Hopkins Lung Project data using both maximum likelihood estimation and Bayesian Markov chain Monte Carlo. PMID:23129110

  7. Productivity in dental care for children. Factors influencing the time spent delivering dental care.

    PubMed

    Wang, N J

    1994-12-01

    The cost of dental services is related to their productivity. The purpose of the study was to identify factors influencing productivity, measured as time spent providing dental care per child under care, per year, in public dental clinics. The time was expected to vary with characteristics of the patients, the personnel and the clinics. Time spent by dentists and dental hygienists delivering dental care for children aged three to 18 years was obtained from 137 public dental clinics. The data showed substantial variation in productivity between clinics. Multiple regression analysis revealed that the time spent per child was associated with interval between examinations, proportion of male dentists, ratio of dental assistants to dentists, proportion of child treatment time given by dental hygienists and proportion of all treatment time spent on child patients. These variables explained 43 per cent of the variance in the total time spent by dentists and hygienists and 41 per cent of the variance in dentists' time. Individual dentists and hygienists may reduce the mean time spent per child by extending recall intervals. On an administrative level, dentists' time per child may be reduced by employing more dental assistants or dental hygienists and allowing dentists to treat patient groups other than children. It is concluded that productivity in dental care for children in the public dental services may be influenced in several ways, both by clinical and administrative decisions. PMID:7850642

  8. Grey Literature Searching for Health Sciences Systematic Reviews: A Prospective Study of Time Spent and Resources Utilized

    PubMed Central

    Saleh, Ahlam A.; Ratajeski, Melissa A.; Bertolet, Marnie

    2015-01-01

    Objective To identify estimates of time taken to search grey literature in support of health sciences systematic reviews and to identify searcher or systematic review characteristics that may impact resource selection or time spent searching. Methods A survey was electronically distributed to searchers embarking on a new systematic review. Characteristics of the searcher and systematic review were collected along with time spent searching and what resources were searched. Time and resources were tabulated and resources were categorized as grey or non-grey. Data was analyzed using Kruskal-Wallis tests. Results Out of 81 original respondents, 21% followed through with completion of the surveys in their entirety. The median time spent searching all resources was 471 minutes, and of those a median of 85 minutes were spent searching grey literature. The median number of resources used in a systematic review search was four and the median number of grey literature sources searched was two. The amount of time spent searching was influenced by whether the systematic review was grant funded. Additionally, the number of resources searched was impacted by institution type and whether systematic review training was received. Conclusions This study characterized the amount of time for conducting systematic review searches including searching the grey literature, in addition to the number and types of resources used. This may aid searchers in planning their time, along with providing benchmark information for future studies. This paper contributes by quantifying current grey literature search patterns and associating them with searcher and review characteristics. Further discussion and research into the search approach for grey literature in support of systematic reviews is encouraged. PMID:25914722

  9. 76 FR 33121 - List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... was published in the Federal Register on March 28, 2011 (76 FR 17019). This direct final rule amended....gov . SUPPLEMENTARY INFORMATION: On March 28, 2011 (76 FR 17019), the NRC published a direct final... 3150-AI90 List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition AGENCY:...

  10. Traditional Sex Role Development and Amount of Time Spent Watching Television

    ERIC Educational Resources Information Center

    Frueh, Terry; McGhee, Paul E.

    1975-01-01

    Tested the hypothesis that the amount of time spent watching television would be significantly related to the strength of traditional sex role development. Subjects were 80 kindergarten and elementary school children. (SDH)

  11. Time Spent on Home Food Preparation and Indicators of Healthy Eating

    PubMed Central

    Monsivais, Pablo; Aggarwal, Anju; Drewnowski, Adam

    2014-01-01

    Background The amount of time spent on food preparation and cooking may have implications for diet quality and health. However, little is known about how food-related time use relates to food consumption and spending, either at restaurants or for food consumed at home. Purpose To quantitatively assess the associations among the amount of time habitually spent on food preparation and patterns of self-reported food consumption, food spending, and frequency of restaurant use. Methods This was a cross-sectional study of 1,319 adults in a population-based survey conducted in 2008–2009. The sample was stratified into those who spent <1 hour/day, 1–2 hours/day, and >2 hours/day on food preparation and clean-up. Descriptive statistics and multivariable regression models examined differences between time-use groups. Analyses were conducted in 2011–2013. Results Individuals who spent the least amount of time on food preparation tended to be working adults who placed a high priority on convenience. Greater amount of time spent on food preparation was associated with indicators of higher diet quality, including significantly more frequent intake of vegetables, salads, fruits, and fruit juices. Spending less than 1 hour/day on food preparation was associated with significantly more money spent on food away from home and more frequent use of fast food restaurants compared to those who spent more time on food preparation. Conclusions The findings indicate that time might be an essential ingredient in the production of healthier eating habits among adults. Further research should investigate the determinants of spending time on food preparation. PMID:25245799

  12. Data Mining Techniques to Estimate Plutonium, Initial Enrichment, Burnup, and Cooling Time in Spent Fuel Assemblies

    SciTech Connect

    Trellue, Holly Renee; Fugate, Michael Lynn; Tobin, Stephen Joesph

    2015-03-19

    The Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and Arms Control (NPAC), National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE) has sponsored a multi-laboratory, university, international partner collaboration to (1) detect replaced or missing pins from spent fuel assemblies (SFA) to confirm item integrity and deter diversion, (2) determine plutonium mass and related plutonium and uranium fissile mass parameters in SFAs, and (3) verify initial enrichment (IE), burnup (BU), and cooling time (CT) of facility declaration for SFAs. A wide variety of nondestructive assay (NDA) techniques were researched to achieve these goals [Veal, 2010 and Humphrey, 2012]. In addition, the project includes two related activities with facility-specific benefits: (1) determination of heat content and (2) determination of reactivity (multiplication). In this research, a subset of 11 integrated NDA techniques was researched using data mining solutions at Los Alamos National Laboratory (LANL) for their ability to achieve the above goals.

  13. Leisure Time Spent Sitting in Relation to Total Mortality in a Prospective Cohort of US Adults

    PubMed Central

    Patel, Alpa V.; Bernstein, Leslie; Deka, Anusila; Feigelson, Heather Spencer; Campbell, Peter T.; Gapstur, Susan M.; Colditz, Graham A.; Thun, Michael J.

    2010-01-01

    The obesity epidemic is attributed in part to reduced physical activity. Evidence supports that reducing time spent sitting, regardless of activity, may improve the metabolic consequences of obesity. Analyses were conducted in a large prospective study of US adults enrolled by the American Cancer Society to examine leisure time spent sitting and physical activity in relation to mortality. Time spent sitting and physical activity were queried by questionnaire on 53,440 men and 69,776 women who were disease free at enrollment. The authors identified 11,307 deaths in men and 7,923 deaths in women during the 14-year follow-up. After adjustment for smoking, body mass index, and other factors, time spent sitting (≥6 vs. <3 hours/day) was associated with mortality in both women (relative risk = 1.34, 95% confidence interval (CI): 1.25, 1.44) and men (relative risk = 1.17, 95% CI: 1.11, 1.24). Relative risks for sitting (≥6 hours/day) and physical activity (<24.5 metabolic equivalent (MET)-hours/week) combined were 1.94 (95% CI: 1.70, 2.20) for women and 1.48 (95% CI: 1.33, 1.65) for men, compared with those with the least time sitting and most activity. Associations were strongest for cardiovascular disease mortality. The time spent sitting was independently associated with total mortality, regardless of physical activity level. Public health messages should include both being physically active and reducing time spent sitting. PMID:20650954

  14. Teacher time spent on student health issues and school nurse presence.

    PubMed

    Hill, Nina Jean; Hollis, Marianne

    2012-06-01

    Elementary school teacher time spent on student health issues and the relationship to school nurse services was the focus of this 2-year study. A cross-sectional design was used to survey traditional and exceptional (special needs) classroom teachers about the time they spent on health issues and their perception of school nurse presence. The school nurses were surveyed regarding the impact of their presence on early releases due to illness. Study findings related to teacher perceptions indicate with school nurse presence there are fewer early releases, increased communication, less time spent on health issues, students with chronic illnesses are safer, and there is a resource available for health information. The data provide the groundwork for discussions to improve the communication of the nurses' schedules, increase teacher confidence in consistent nurse hours at their school and aid the nurse in protecting valuable on-site school hours from other interferences or commitments. PMID:22140140

  15. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... other than that selected by the agency, shall be credited with the lesser of: (1) The actual travel time which is hours of work under this section; or (2) The estimated travel time which would have been... Administration (41 CFR 300-3.1)....

  16. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... other than that selected by the agency, shall be credited with the lesser of: (1) The actual travel time which is hours of work under this section; or (2) The estimated travel time which would have been... Administration (41 CFR 300-3.1)....

  17. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... other than that selected by the agency, shall be credited with the lesser of: (1) The actual travel time which is hours of work under this section; or (2) The estimated travel time which would have been... Administration (41 CFR 300-3.1)....

  18. 5 CFR 551.422 - Time spent traveling.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... other than that selected by the agency, shall be credited with the lesser of: (1) The actual travel time which is hours of work under this section; or (2) The estimated travel time which would have been... Administration (41 CFR 300-3.1)....

  19. Prevalence and socio-demographic correlates of time spent cooking by adults in the 2005 UK Time Use Survey. Cross-sectional analysis.

    PubMed

    Adams, Jean; White, Martin

    2015-09-01

    This study aimed to document the prevalence and socio-demographic correlates of time spent cooking by adults in the 2005 UK Time-Use Survey. Respondents reported their main activities, in 10 minute slots, throughout one 24 hour period. Activities were coded into 30 pre-defined codes, including 'cooking, washing up'. Four measures of time spent cooking were calculated: any time spent cooking, 30 continuous minutes spent cooking, total time spent cooking, and longest continuous time spent cooking. Socio-demographic correlates were: age, employment, social class, education, and number of adults and children in the household. Analyses were stratified by gender. Data from 4214 participants were included. 85% of women and 60% of men spent any time cooking; 60% of women and 33% of men spent 30 continuous minutes cooking. Amongst women, older age, not being in employment, lower social class, greater education, and living with other adults or children were positively associated with time cooking. Few differences in time spent cooking were seen in men. Socio-economic differences in time spent cooking may have been overstated as a determinant of socio-economic differences in diet, overweight and obesity. Gender was a stronger determinant of time spent cooking than other socio-demographic variables. PMID:26004671

  20. Prevalence and socio-demographic correlates of time spent cooking by adults in the 2005 UK Time Use Survey. Cross-sectional analysis☆

    PubMed Central

    Adams, Jean; White, Martin

    2015-01-01

    This study aimed to document the prevalence and socio-demographic correlates of time spent cooking by adults in the 2005 UK Time-Use Survey. Respondents reported their main activities, in 10 minute slots, throughout one 24 hour period. Activities were coded into 30 pre-defined codes, including ‘cooking, washing up’. Four measures of time spent cooking were calculated: any time spent cooking, 30 continuous minutes spent cooking, total time spent cooking, and longest continuous time spent cooking. Socio-demographic correlates were: age, employment, social class, education, and number of adults and children in the household. Analyses were stratified by gender. Data from 4214 participants were included. 85% of women and 60% of men spent any time cooking; 60% of women and 33% of men spent 30 continuous minutes cooking. Amongst women, older age, not being in employment, lower social class, greater education, and living with other adults or children were positively associated with time cooking. Few differences in time spent cooking were seen in men. Socio-economic differences in time spent cooking may have been overstated as a determinant of socio-economic differences in diet, overweight and obesity. Gender was a stronger determinant of time spent cooking than other socio-demographic variables. PMID:26004671

  1. The independent relationship between trouble controlling Facebook use, time spent on the site and distress

    PubMed Central

    Muench, Fredrick; Hayes, Marie; Kuerbis, Alexis; Shao, Sijing

    2015-01-01

    Background and Aims There is an emerging literature base on the relationship between maladaptive traits and “addiction” to social networking sites. These studies have operationalized addiction as either spending excessive amounts of time on social networking sites (SNS) or trouble controlling SNS use, but have not assessed the unique contribution of each of these constructs on outcomes in the same models. Moreover, these studies have exclusively been conducted with younger people rather than a heterogeneous sample. This study examined the independent relationship of a brief Facebook addiction scale, time spent on Facebook, and Facebook checking on positive and negative social domains, while controlling for self-esteem and social desirability. Methods Participants were recruited using e-mail, SNS posts and through Amazon’s MTurk system. The sample included 489 respondents ages from 18 to approximately 70, who completed a 10–15 minute survey. Results Results indicate that neither time spent on Facebook nor Facebook checking was significantly associated with either self-esteem, fear of negative social evaluation or social comparison, while SNS addiction symptoms were each independently associated with Facebook usage. Neither time spent on Facebook nor SNS addiction symptoms were associated with positive social relationships. Discussion Overall results suggest that time on SNS and trouble controlling use should be considered independent constructs and that interventions should target underlying loss of control as the primary intervention target above ego syntonic time spent on the site. PMID:26551906

  2. Determining Spent Nuclear Fuel's Plutonium Content, Initial Enrichment, Burnup, and Cooling Time

    SciTech Connect

    Cheatham, Jesse R; Francis, Matthew W

    2011-01-01

    The Next Generation of Safeguards Initiative is examining nondestructive assay techniques to determine the total plutonium content in spent nuclear fuel. The goal of this research was to develop new techniques that can independently verify the plutonium content in a spent fuel assembly without relying on an operator's declarations. Fundamentally this analysis sought to answer the following questions: (1) do spent fuel assemblies contain unique, identifiable isotopic characteristics as a function of their burnup, cooling time, and initial enrichment; (2) how much variation can be seen in spent fuel isotopics from similar and dissimilar reactor power operations; and (3) what isotopes (if any) could be used to determine burnup, cooling time, and initial enrichment? To answer these questions, 96,000 ORIGEN cases were run that simulated typical two-cycle operations with burnups ranging from 21,900 to 72,000 MWd/MTU, cooling times from 5 to 25 years, and initial enrichments between 3.5 and 5.0 weight percent. A relative error coefficient was determined to show how numerically close a reference solution has to be to another solution for the two results to be indistinguishable. By looking at the indistinguishable solutions, it can be shown how a precise measurement of spent fuel isotopics can be inconclusive when used in the absence of an operator's declarations. Using this Method of Indistinguishable Solutions (MIS), we evaluated a prominent method of nondestructive analysis - gamma spectroscopy. From this analysis, a new approach is proposed that demonstrates great independent forensic examination potential for spent nuclear fuel by examining both the neutron emissions of Cm-244 and the gamma emissions of Cs-134 and Eu-154.

  3. 5 CFR 551.424 - Time spent adjusting grievances or performing representational functions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Time spent adjusting grievances or performing representational functions. 551.424 Section 551.424 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of...

  4. Cut-Off: How We Spent Our Time in a Residential School

    ERIC Educational Resources Information Center

    French, Sally

    2010-01-01

    This article documents the ways in which both pupils and care staff spent their time in a residential school for children with physical disabilities and mild learning disabilities in the 1960s. It is told from the perspective of the author, who worked at the school as an assistant housemother, and two of her co-workers who responded to an…

  5. 5 CFR 551.424 - Time spent adjusting grievances or performing representational functions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work... shall be considered hours of work. (b) “Official time” granted an employee by an agency to perform... hours of work. This includes time spent by an employee performing such functions during regular...

  6. The Relationship between a Counselor's Education and Experience and the Time Spent on Tasks

    ERIC Educational Resources Information Center

    Lustig, Dan C.; Strauser, David R.

    2008-01-01

    The purpose of the current study was to examine the relationship between perceived percentage of time spent on rehabilitation counseling responsibilities and the possession of an educational degree, certification as a rehabilitation counselor, and years worked for a state or federal vocational rehabilitation agency. A national study was conducted…

  7. 5 CFR 551.423 - Time spent in training or attending a lecture, meeting, or conference.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work Application of Principles in Relation to Other Activities § 551.423 Time spent in training or attending a... training under the Veterans Recruitment Act (5 CFR part 307) outside regular working hours shall not...

  8. Re-Examining Gender Differences in Video Game Play: Time Spent and Feelings of Success

    ERIC Educational Resources Information Center

    Hamlen, Karla R.

    2010-01-01

    Research has shown that, among children, boys tend to play video games more than girls do. There are several theories addressing this phenomenon, including that stereotypes and lack of opportunity leave girls feeling inadequate with certain types of technology. No research has yet examined the interactive relationships between time spent playing…

  9. Parent Perceptions of Time Spent Meaningfully by Young Adults with Pervasive Support Needs

    ERIC Educational Resources Information Center

    Rossetti, Zachary; Lehr, Donna; Lederer, Leslie; Pelerin, Dana; Huang, Shuoxi

    2015-01-01

    This article describes a qualitative study that examined how 23 young adults with pervasive support needs and limited functional communication spent their time and how their parents (n = 23) and direct support professionals (DSPs; n = 2) defined meaningfulness in relation to the young adults' experiences. Data were collected through…

  10. Naturally Occurring Changes in Time Spent Watching Television Are Inversely Related to Frequency of Physical Activity during Early Adolescence

    ERIC Educational Resources Information Center

    Motl, Robert W.; McAuley, Edward; Birnbaum, Amanda S.; Lytle, Leslie A.

    2006-01-01

    In this longitudinal study, we examined the relationship between changes in time spent watching television and playing video games with frequency of leisure-time physical activity across a 2-year period among adolescent boys and girls (N=4594). Latent growth modelling indicated that a decrease in time spent watching television was associated with…

  11. Relation between time spent outdoors and exfoliation glaucoma or exfoliation glaucoma suspect

    PubMed Central

    Kang, Jae Hee; Wiggs, Janey L.; Pasquale, Louis R.

    2014-01-01

    Purpose To evaluate the relation between time spent outdoors at various life periods and risk of exfoliation glaucoma or exfoliation glaucoma suspect. Design Retrospective cohort study in the United States. Methods Participants (49,033 women in the Nurses Health Study and 20,066 men in the Health Professionals Follow-up Study) were 60+ years old, free of glaucoma and cataract, reported eye exams and completed questions about time spent outdoors in direct sunlight at mid-day at 3 life periods: high school to age 24 years, age 25-35 years, and age 36-59 years (asked in 2006 in women and 2008 in men). Participants were followed biennially with mailed questionnaires from 1980 (women) / 1986 (men) to 2010. Incident cases (223 women and 38 men) were confirmed with medical records. Cohort-specific multivariable-adjusted rate ratios from Cox proportional hazards models were estimated and pooled with meta-analysis. Results Although no association was observed with greater time spent outdoors in the ages of 25-35 or ages 36-59 years, the pooled multivariable-adjusted rate ratios for ≥11 hours per week spent outdoors in high school to age 24 years compared with ≤5 hours per week was 2.00 (95% confidence interval=1.30, 3.08; p for linear trend=0.001). In women, this association was stronger in those who resided in the southern geographic tier in young adulthood (p for interaction = 0.07). Conclusions Greater time spent outdoors in young adulthood was associated with risk of exfoliation glaucoma or exfoliation glaucoma suspect, supporting an etiologic role of early exposures to climatic factors. PMID:24857689

  12. Maternal employment, acculturation, and time spent in food-related behaviors among Hispanic mothers in the United States. Evidence from the American Time Use Survey.

    PubMed

    Sliwa, Sarah A; Must, Aviva; Peréa, Flavia; Economos, Christina D

    2015-04-01

    Employment is a major factor underlying im/migration patterns. Unfortunately, lower diet quality and higher rates of obesity appear to be unintended consequences of moving to the US. Changes in food preparation practices may be a factor underlying dietary acculturation. The relationships between employment, acculturation, and food-related time use in Hispanic families have received relatively little attention. We used cross-sectional data collected from Hispanic mothers (ages 18-65) with at least one child <13 years old participating in the 2003-2011 American Time Use Survey (n = 3622) to estimate the relationship between employment, acculturation (US-born vs. im/migrant), and time spent in food preparation and family dinner. Regression models were estimated separately for the employed and the non-working and were adjusted for Hispanic origin group, socio-demographic and household characteristics. Working an eight-hour day was associated with spending 38 fewer minutes in food preparation (-38.0 ± SE 4.8, p < 001). Although being US-born was associated with spending fewer minutes in food preparation, this relationship varied by origin group. Acculturation did not appear to modify the relationship between hours worked and time spent in food preparation or family dinner. Mothers who worked late hours spent less time eating the evening meal with their families (-9.8 ± SE 1.3). Although an eight-hour workday was associated with a significant reduction in food preparation time, an unexpected result is that, for working mothers, additional time spent in paid work is not associated with the duration of family dinner later that day. PMID:25451579

  13. Estimating the time since discharge of spent cartridges: a logical approach for interpreting the evidence.

    PubMed

    Gallidabino, Matteo; Weyermann, Céline; Romolo, Francesco Saverio; Taroni, Franco

    2013-03-01

    Estimating the time since discharge of a spent cartridge or a firearm can be useful in criminal situations involving firearms. The analysis of volatile gunshot residue remaining after shooting using solid-phase microextraction (SPME) followed by gas chromatography (GC) was proposed to meet this objective. However, current interpretative models suffer from several conceptual drawbacks which render them inadequate to assess the evidential value of a given measurement. This paper aims to fill this gap by proposing a logical approach based on the assessment of likelihood ratios. A probabilistic model was thus developed and applied to a hypothetical scenario where alternative hypotheses about the discharge time of a spent cartridge found on a crime scene were forwarded. In order to estimate the parameters required to implement this solution, a non-linear regression model was proposed and applied to real published data. The proposed approach proved to be a valuable method for interpreting aging-related data. PMID:23380061

  14. Breast IMRT Reduces Time Spent with Acute Dermatitis For Women of All Breast Sizes During Radiation

    PubMed Central

    Freedman, Gary M; Li, Tianyu; Nicolaou, Nicos; Chen, Yan; Ma, Charlie C-M; Anderson, Penny R

    2009-01-01

    Purpose To study the time spent with radiation-induced dermatitis during a course of radiation therapy for breast cancer in women treated with conventional or intensity-modulated radiation therapy (IMRT). Materials and methods The study population consisted of 804 consecutive women with early-stage breast cancer treated with breast-conserving surgery and radiation from 2001 – 2006. All patients were treated with whole-breast radiation followed by a boost to the tumor bed. Whole-breast radiation consisted of conventional wedged photon tangents (n=405) earlier in the study period and mostly of photon IMRT (n=399) in later years. All patients had acute dermatitis graded each week of treatment. Results The breakdown of the cases of maximum acute dermatitis by grade was as follows: 3%, grade 0; 34%, grade 1; 61%, grade 2; and 2%, grade 3. The breakdown of cases of maximum toxicity by technique was as follows: 48%, grade 0/1, and 52%, grade 2/3, for IMRT, and 25%, grade 0/1, and 75%, grade 2/3, for conventional radiation therapy (p<0.0001). IMRT patients spent 82% of weeks during treatment with grade 0/1 dermatitis and 18% with grade 2/3 dermatitis, compared with 29% and 71% of patients, respectively, treated with conventional radiation (p<0.0001). Further, the time spent with grade 2/3 toxicity was decreased in IMRT patients with small (p=0.0015), medium (p<0.0001), and large (p<0.0001) breasts. Conclusions Breast IMRT is associated with both a significant decrease in the time spent during treatment with grade 2/3 dermatitis and in the maximum severity of dermatitis compared with conventional radiation regardless of breast size. PMID:19362779

  15. Human mobility and time spent at destination: impact on spatial epidemic spreading.

    PubMed

    Poletto, Chiara; Tizzoni, Michele; Colizza, Vittoria

    2013-12-01

    Host mobility plays a fundamental role in the spatial spread of infectious diseases. Previous theoretical works based on the integration of network theory into the metapopulation framework have shown that the heterogeneities that characterize real mobility networks favor the propagation of epidemics. Nevertheless, the studies conducted so far assumed the mobility process to be either Markovian (in which the memory of the origin of each traveler is lost) or non-Markovian with a fixed traveling time scale (in which individuals travel to a destination and come back at a constant rate). Available statistics however show that the time spent by travelers at destination is characterized by wide fluctuations, ranging from a single day up to several months. Such varying length of stay crucially affects the chance and duration of mixing events among hosts and may therefore have a strong impact on the spread of an emerging disease. Here, we present an analytical and a computational study of epidemic processes on a complex subpopulation network where travelers have memory of their origin and spend a heterogeneously distributed time interval at their destination. Through analytical calculations and numerical simulations we show that the heterogeneity of the length of stay alters the expression of the threshold between local outbreak and global invasion, and, moreover, it changes the epidemic behavior of the system in case of a global outbreak. Additionally, our theoretical framework allows us to study the effect of changes in the traveling behavior in response to the infection, by considering a scenario in which sick individuals do not leave their home location. Finally, we compare the results of our non-Markovian framework with those obtained with a classic Markovian approach and find relevant differences between the two, in the estimate of the epidemic invasion potential, as well as of the timing and the pattern of its spatial spread. These results highlight the importance of

  16. Labor time spent in foodservice activities in one hospital: a 12-year profile.

    PubMed

    Matthews, M E; Zardain, M V; Mahaffey, M J

    1986-05-01

    Labor minutes per meal equivalent and percentage of time spent in direct work, indirect work, delay time, and total time were determined in an annual study of foodservice workers in a community hospital. Twelve activity sampling studies (from 1973 through 1984) were conducted for 7 days (Monday through Sunday), usually during the second week of February. The conventional foodservice, with the cook/hot-hold method of food production and service, averaged about 10 minutes for direct work, 1 minute for indirect work, 2 minutes for delay time, and 13 total labor minutes per meal equivalent for the 12 years. The data were similar to those of the study in the 1960s, of conventional hospital foodservices, with high productivity, which averaged about 11 minutes for direct work, 1 minute for indirect work, 2 minutes for delay time, and 14 total labor minutes per meal equivalent. Data averaged from the 1973 through 1984 studies compared with the data from the 1960s study showed that transportation, cleaning, and service required the most labor time (total of 58% in this study and total of 62% in the 1960s study). Methods reported in this article may be applied in other foodservices to identify labor time spent in work and delay activities to establish productivity guidelines for a foodservice department. PMID:3700926

  17. Time spent sitting during and outside working hours in bus drivers: A pilot study

    PubMed Central

    Varela-Mato, Veronica; Yates, Thomas; Stensel, David J.; Biddle, Stuart J.H.; Clemes, Stacy A.

    2015-01-01

    This cross-sectional pilot study objectively measured sedentary and non-sedentary time in a sample of bus drivers from the East Midlands, United Kingdom. Participants wore an activPAL3 inclinometer for 7 days and completed a daily diary. Driver's blood pressure, heart rate, waist circumference and body composition were measured objectively at the outset. The proportions of time spent sedentary and non-sedentary were calculated during waking hours on workdays and non-workdays and during working-hours and non-working-hours on workdays. 28 (85% of those enrolled into the study) provided valid objective monitoring data (89.3% male, [median ± IQR] age: 45.2 ± 12.8 years, BMI 28.1 ± 5.8 kg/m2). A greater proportion of time was spent sitting on workdays than non-workdays (75% [724 ± 112 min/day] vs. 62% [528 ± 151 min/day]; p < 0.001), and during working-hours than non-working-hours (83% [417 ± 88 min/day] vs. 68% [307 ± 64 min/day]; p < 0.001) on workdays. Drivers spent less than 3% of their overall time stepping. Bus drivers accumulate high levels of sitting time during working-hours and outside working-hours. Interventions are urgently needed in this at-risk group, which should focus on reducing sitting and increasing movement during breaks and increasing physical activity during leisure time to improve cardiovascular health. PMID:26844184

  18. Time spent sitting during and outside working hours in bus drivers: A pilot study.

    PubMed

    Varela-Mato, Veronica; Yates, Thomas; Stensel, David J; Biddle, Stuart J H; Clemes, Stacy A

    2016-06-01

    This cross-sectional pilot study objectively measured sedentary and non-sedentary time in a sample of bus drivers from the East Midlands, United Kingdom. Participants wore an activPAL3 inclinometer for 7 days and completed a daily diary. Driver's blood pressure, heart rate, waist circumference and body composition were measured objectively at the outset. The proportions of time spent sedentary and non-sedentary were calculated during waking hours on workdays and non-workdays and during working-hours and non-working-hours on workdays. 28 (85% of those enrolled into the study) provided valid objective monitoring data (89.3% male, [median ± IQR] age: 45.2 ± 12.8 years, BMI 28.1 ± 5.8 kg/m(2)). A greater proportion of time was spent sitting on workdays than non-workdays (75% [724 ± 112 min/day] vs. 62% [528 ± 151 min/day]; p < 0.001), and during working-hours than non-working-hours (83% [417 ± 88 min/day] vs. 68% [307 ± 64 min/day]; p < 0.001) on workdays. Drivers spent less than 3% of their overall time stepping. Bus drivers accumulate high levels of sitting time during working-hours and outside working-hours. Interventions are urgently needed in this at-risk group, which should focus on reducing sitting and increasing movement during breaks and increasing physical activity during leisure time to improve cardiovascular health. PMID:26844184

  19. Gamma spectrometric characterization of short cooling time nuclear spent fuels using hemispheric CdZnTe detectors

    NASA Astrophysics Data System (ADS)

    Lebrun, A.; Bignan, G.; Szabo, J. L.; Arenas-Carrasco, J.; Arlt, R.; Dubreuil, A.; Esmailpur Kazerouni, K.

    2000-07-01

    After years of cooling, nuclear spent fuel gamma emissions are mainly due to caesium isotopes which are emitters at 605, 662 and 796-801 keV. Extensive work has been done on such fuels using various CdTe or CdZnTe probes. When fuels have to be measured after short cooling time (during NPP outage) the spectrum is much more complex due to the important contributions of niobium and zirconium in the 700 keV range. For the first time in a nuclear power plant, four spent fuels of the Kozloduy VVER reactor no 4 were measured during outage, 37 days after shutdown of the reactor. In such conditions, good resolution is of particular interest, so a 20 mm 3 hemispheric crystal was used with a resolution better than 7 keV at 662 keV. This paper presents the experimental device and analyzes the results which show that CdZnTe commercially available detectors enabled us to perform a semi-quantitative determination of the burn-up after a short cooling time. In addition, it is discussed how a burn-up evolution code (CESAR) coupled to a gamma transport code (MCNP) allows us to predict and interpret the experimental data from CdZnTe detectors. Particularly, bremsstrahlung contribution to the gamma spectra is suggested and modeled. Calculation results indicate a good agreement between this hypothesis and the present measurements.

  20. 76 FR 17037 - List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-28

    ...; ] NUCLEAR REGULATORY COMMISSION 10 CFR Part 72 RIN 3150-AI90 List of Approved Spent Fuel Storage Casks: HI... regulations to add the HI-STORM Flood/Wind cask system to the ``List of Approved Spent Fuel Storage Casks... 13, 2011. SAR Submitted by: Holtec International, Inc. SAR Title: Safety Analysis Report on the...

  1. Time Spent Walking and Risk of Diabetes in Japanese Adults: The Japan Public Health Center-Based Prospective Diabetes Study

    PubMed Central

    Kabeya, Yusuke; Goto, Atsushi; Kato, Masayuki; Matsushita, Yumi; Takahashi, Yoshihiko; Isogawa, Akihiro; Inoue, Manami; Mizoue, Tetsuya; Tsugane, Shoichiro; Kadowaki, Takashi; Noda, Mitsuhiko

    2016-01-01

    Background The association between time spent walking and risk of diabetes was investigated in a Japanese population-based cohort. Methods Data from the Japan Public Health Center-based Prospective Diabetes cohort were analyzed. The surveys of diabetes were performed at baseline and at the 5-year follow-up. Time spent walking per day was assessed using a self-reported questionnaire (<30 minutes, 30 minutes to <1 hour, 1 to <2 hours, or ≥2 hours). A cross-sectional analysis was performed among 26 488 adults in the baseline survey. Logistic regression was used to examine the association between time spent walking and the presence of unrecognized diabetes. We then performed a longitudinal analysis that was restricted to 11 101 non-diabetic adults who participated in both the baseline and 5-year surveys. The association between time spent walking and the incidence of diabetes during the 5 years was examined. Results In the cross-sectional analysis, 1058 participants had unrecognized diabetes. Those with time spent walking of <30 minutes per day had increased odds of having diabetes in relation to those with time spent walking of ≥2 hours (adjusted odds ratio [OR] 1.23; 95% CI, 1.02–1.48). In the longitudinal analysis, 612 participants developed diabetes during the 5 years of follow-up. However, a significant association between time spent walking and the incidence of diabetes was not observed. Conclusions Increased risk of diabetes was implied in those with time spent walking of <30 minutes per day, although the longitudinal analysis failed to show a significant result. PMID:26725285

  2. Time to care? Health of informal older carers and time spent on health related activities: an Australian survey

    PubMed Central

    2013-01-01

    Background Little is known about the time spent on specific health related activities by older adult informal carers who assist people with chronic illness. Research has not yet addressed the association between carer health status and their care demands. Such information could inform policy and health system efforts to manage chronic illness. Methods We conducted an Australia wide survey using recall questionnaires to record time use. The study asked how much time is spent on “most days” for the most common activities like taking medication, self-treatment and testing, and how much time in the last month on less common activities like attending a physician or shopping associated with health needs. The survey was mailed to 5,000 members of National Seniors Australia; 2,500 registrants on the National Diabetes Services Scheme; and 3,100 members of the Australian Lung Foundation. A total of 2519 people responded, including 313 people who identified as informal carers. Statistical analysis was undertaken using Stata 11. Standard errors and confidence intervals were derived using bootstrapping techniques within Stata 11. Results Most carers (96.2%) had chronic illness themselves, and those with greater numbers of chronic illnesses were those who faced the greatest overall time demands. The top decile of carers devoted between 8.5 and 10 hours a day to personal and caring health related activities. Informal carers with chronic illness spent more time managing their own health than people with chronic illness who were not informal carers. These carers spent more time on caring for others than on caring for their own health. High levels of caring responsibility were associated with poorer reported carer health. Conclusions Policy and health care services will need to adapt to recognise and reduce the time burden on carers who themselves have chronic illness. More carefully targeted investment in the social infrastructure of formal care would free up carers for other

  3. 43 CFR 3430.2-2 - Additional time.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Additional time. 3430.2-2 Section 3430.2-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) NONCOMPETITIVE LEASES Preference Right Leases § 3430.2-2 Additional time. (a) If the...

  4. Naturally occurring changes in time spent watching television are inversely related to frequency of physical activity during early adolescence.

    PubMed

    Motl, Robert W; McAuley, Edward; Birnbaum, Amanda S; Lytle, Leslie A

    2006-02-01

    In this longitudinal study, we examined the relationship between changes in time spent watching television and playing video games with frequency of leisure-time physical activity across a 2-year period among adolescent boys and girls (N=4594). Latent growth modelling indicated that a decrease in time spent watching television was associated with an increase in frequency of leisure-time physical activity. That relationship was strong in magnitude and independent of sex, socioeconomic status, smoking, and the value participants placed on health, appearance, and achievement. Our results encourage the design of interventions that reduce television watching as a possible means of increasing adolescent physical activity. PMID:16338428

  5. Ultrafast amplifier additive timing jitter characterization and control.

    PubMed

    Casanova, Alexis; D'Acremont, Quentin; Santarelli, Giorgio; Dilhaire, Stefan; Courjaud, Antoine

    2016-03-01

    We report on the characterization and long-term compensation of additive timing jitter introduced by a femtosecond ytterbium regenerative amplifier with a 100 kHz repetition rate. A balanced optical cross-correlation technique is used to generate a jitter error signal. This approach is well suited to characterize the additive timing jitter of Yb amplifiers seeded by narrow spectrum Yb oscillators. The balanced optical cross-correlator is in a noncollinear configuration allowing a background free coindence detection. This setup enables the measurement of additive timing jitter from the amplifier, with a noise floor of 300 as integrated from 10 Hz to 10 kHz. The measured additive timing jitter level is about 5 fs, integrated from 0.1 Hz to 10 kHz. The amplifier timing drift characterization and control are performed for more than an hour. PMID:26974074

  6. 76 FR 17019 - List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-28

    ... part 72, entitled ``General License for Storage of Spent Fuel at Power Reactor Sites'' (55 FR 29181..., 1997, and published in the Federal Register on September 3, 1997 (62 FR 46517), this rule is classified... June 10, 1998 (63 FR 31883), directed that the Government's documents be in clear and...

  7. Time Well Spent: Eight Powerful Practices of Successful, Expanded-Time Schools

    ERIC Educational Resources Information Center

    Kaplan, Claire; Chan, Roy

    2012-01-01

    This report reshapes the field for expanded-time schools by outlining specific practices that can lead to dramatic increases in student achievement and preparation for success in college and the workforce. This report offers an in-depth examination of 30 expanded-time schools serving high-poverty populations with impressive track records of…

  8. 5 CFR 551.431 - Time spent on standby duty or in an on-call status.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-call status. 551.431 Section 551.431 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL... § 551.431 Time spent on standby duty or in an on-call status. (a)(1) An employee is on duty, and time... in an on-call status shall not be considered hours of work if: (1) The employee is allowed to leave...

  9. Time spent on health related activities associated with chronic illness: a scoping literature review

    PubMed Central

    2012-01-01

    Background The management of health care, particularly for people with chronic conditions, combines the activities of health professionals, patients, informal carers and social networks that support them. Understanding the non-professional roles in health management requires information about the health related activities (HRA) that are undertaken by patients and informal carers. This understanding allows management planning that incorporates the capacity of patients and informal carers, as well as identifying the particular skills, knowledge and technical support that are necessary. This review was undertaken to identify how much time people with chronic illness and their informal carers spend on HRA. Methods Literature searches of three electronic databases (CINAHL, Medline, and PubMed) and two journals (Time and Society, Sociology of Health and Illness) were carried out in 2011 using the following search terms (and derivatives): chronic illness AND time AND consumer OR carer. The search was aimed at finding studies of time spent on HRA. A scoping literature review method was utilised. Results Twenty-two peer reviewed articles published between 1990 and 2010 were included for review. The review identified limited but specific studies about time use by people with a chronic illness and/or their carers. While illness work was seen as demanding, few studies combined inquiry about both defined tasks and defined time use. It also identified methodological issues such as consistency of definition and data collection methods, which remain unresolved. Conclusions While HRA are seen as demanding by people doing them, few studies have measured actual time taken to carry out a comprehensive range of HRA. The results of this review suggest that both patients with chronic illness and informal carers may be spending 2 hours a day or more on HRA. Illnesses such as diabetes may be associated with higher time use. More empirical research is needed to understand the time demands

  10. Among Inpatients, Posttraumatic Stress Disorder Symptom Severity Is Negatively Associated With Time Spent Walking.

    PubMed

    Rosenbaum, Simon; Vancampfort, Davy; Tiedemann, Anne; Stubbs, Brendon; Steel, Zachary; Ward, Philip B; Berle, David; Sherrington, Catherine

    2016-01-01

    This study aimed to determine whether posttraumatic stress disorder (PTSD) symptom severity and psychological and functional variables were associated with physical activity (PA) upon admission to an inpatient facility. PTSD symptoms, depression, anxiety and stress, sleep quality, and PA participation were assessed among 76 participants (age, 47.6 ± 11.9 years; 83% male). Backward stepwise regression analyses identified variables independently associated with time spent walking and engaging in moderate-vigorous PA (MVPA). No significant correlations were found between any of the variables and MVPA. Total PTSD symptoms (r = -0.39, p < 0.001), combined symptoms of depression, anxiety, and stress (r = -0.31, p < 0.01), and sleep behavior (r = -0.24, p < 0.05) were significantly and negatively associated with total walking time. Total PTSD symptoms were the only significant predictor of walking time (B = -0.03, SE = 0.008, β = -0.4; t = -3.4; p < 0.001). Results indicate that increased PTSD symptoms are associated with lower levels of walking. Results highlight the importance of considering symptoms when designing PA programs for people with PTSD. PMID:26558500

  11. Time spent with friends in adolescence relates to less neural sensitivity to later peer rejection

    PubMed Central

    Telzer, Eva H.; Fuligni, Andrew J.; Lieberman, Matthew D.; Eisenberger, Naomi I.

    2012-01-01

    Involvement with friends carries many advantages for adolescents, including protection from the detrimental effects of being rejected by peers. However, little is known about the mechanisms through which friendships may serve their protective role at this age, or the potential benefit of these friendships as adolescents transition to adulthood. As such, this investigation tested whether friend involvement during adolescence related to less neural sensitivity to social threats during young adulthood. Twenty-one adolescents reported the amount of time they spent with friends outside of school using a daily diary. Two years later they underwent an fMRI scan, during which they were ostensibly excluded from an online ball-tossing game by two same-age peers. Findings from region of interest and whole brain analyses revealed that spending more time with friends during adolescence related to less activity in the dorsal anterior cingulate cortex and anterior insula—regions previously linked with negative affect and pain processing—during an experience of peer rejection 2 years later. These findings are consistent with the notion that positive relationships during adolescence may relate to individuals being less sensitive to negative social experiences later on. PMID:21183457

  12. Relationships of Attitudes toward Homework and Time Spent on Homework to Course Outcomes: The Case of Foreign Language Learning

    ERIC Educational Resources Information Center

    Chang, Charles B.; Wall, Daniel; Tare, Medha; Golonka, Ewa; Vatz, Karen

    2014-01-01

    In previous studies of homework in core academic subjects, positive student attitudes toward homework were linked to higher achievement, whereas time spent on homework showed an inconsistent relationship with achievement. This study examined the generalizability of these findings to foreign language learning by analyzing 2,342 adult students'…

  13. Determinants of Children's Use of and Time Spent in Fast-Food and Full-Service Restaurants

    ERIC Educational Resources Information Center

    McIntosh, Alex; Kubena, Karen S.; Tolle, Glen; Dean, Wesley; Kim, Mi-Jeong; Jan, Jie-Sheng; Anding, Jenna

    2011-01-01

    Objective: Identify parental and children's determinants of children's use of and time spent in fast-food (FF) and full-service (FS) restaurants. Design: Analysis of cross-sectional data. Setting: Parents were interviewed by phone; children were interviewed in their homes. Participants: Parents and children ages 9-11 or 13-15 from 312 families…

  14. Does Time Spent Online Have an Influence on Student Performance? Evidence for a Large Business Studies Class

    ERIC Educational Resources Information Center

    Korkofingas, Con; Macri, Joseph

    2013-01-01

    This paper examines, using regression modelling, whether a statistically significant relationship exists between the time spent by a student using the course website and the student's assessment performance for a large third year university business forecasting course. We utilise the online tracking system in Blackboard, a web-based software…

  15. Group-Based Modeling of Time Spent in Structured Activity Trajectories from Middle Childhood into Early Adolescence

    ERIC Educational Resources Information Center

    Mata, Andrea D.; van Dulmen, Manfred H. M.

    2012-01-01

    This study investigated trajectories of time spent in structured activities from middle childhood to early adolescence by using data from the National Institute of Child Health & Human Development (NICHD) Study of Early Child Care. We used latent class growth analyses and identified five trajectories (stable low, increasing high, decreasing low,…

  16. 29 CFR 516.34 - Exemption from overtime pay for time spent by certain employees receiving remedial education...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Exemption from overtime pay for time spent by certain employees receiving remedial education pursuant to section 7(q) of the Act. 516.34 Section 516.34 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS RECORDS TO BE KEPT BY EMPLOYERS Records Pertaining...

  17. 43 CFR 3430.2-2 - Additional time.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Additional time. 3430.2-2 Section 3430.2-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) NONCOMPETITIVE LEASES Preference Right Leases §...

  18. 43 CFR 3430.2-2 - Additional time.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Additional time. 3430.2-2 Section 3430.2-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) NONCOMPETITIVE LEASES Preference Right Leases §...

  19. 43 CFR 3430.2-2 - Additional time.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Additional time. 3430.2-2 Section 3430.2-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) NONCOMPETITIVE LEASES Preference Right Leases §...

  20. Energy Beyond Food: Foraging Theory Informs Time Spent in Thermals by a Large Soaring Bird

    PubMed Central

    Shepard, Emily L. C.; Lambertucci, Sergio A.; Wilson, Rory P.

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered. PMID:22087301

  1. Curricular Time for Physical Education? A Controlled Experiment in French Canada Asks How Much Curricular Time Should be Spent on Physical Education.

    ERIC Educational Resources Information Center

    Shephard, Roy J.; And Others

    1982-01-01

    A controlled experiment conducted in Canada, the Trois Rivieres regional experiment, investigated the effects of increased physical education instruction on elementary school students. Results indicate that more time can be spent in physical education and that the increased time may result in improvement in other academic areas. (CJ)

  2. Carbohydrate intake is associated with time spent in the euglycemic range in patients with type 1 diabetes

    PubMed Central

    Ayano-Takahara, Shiho; Ikeda, Kaori; Fujimoto, Shimpei; Asai, Kanae; Oguri, Yasuo; Harashima, Shin-ichi; Tsuji, Hidemi; Shide, Kenichiro; Inagaki, Nobuya

    2015-01-01

    Aims/Introduction Greater glycemic variability and lack of predictability are important issues for patients with type 1 diabetes. Dietary factors are one of the contributors to this variability, but how closely diet is linked to glycemic fluctuation on a daily basis has not been investigated. We examined the association between carbohydrate intake and glycemic excursion in outpatients. Materials and Methods A total of 33 patients with type 1 diabetes were included in the analyses (age 44.5 ± 14.7 years, diabetes duration 15.1 ± 8.3 years, 64% female, 30% using insulin pump, glycated hemoglobin 8.1 ± 1.3%). Time spent in euglycemia (70–180 mg/dL), hyperglycemia (>180 mg/dL) and hypoglycemia (<70 mg/dL) of consecutive 48-h periods of continuous glucose monitoring data were collected together with simultaneous records of dietary intake, insulin dose and physical activity. Correlation analyses and multiple regression analyses were used to evaluate the contribution of carbohydrate intake to time spent in the target glycemic range. Results In multiple regression analyses, carbohydrate intake (β = 0.53, P = 0.001), basal insulin dose per kg per day (β = −0.31, P = 0.034) and diabetes duration (β = 0.30, P = 0.042) were independent predictors of time spent in euglycemia. Carbohydrate intake (β = −0.51, P = 0.001) and insulin pump use (β = −0.34, P = 0.024) were independent predictors of time spent in hyperglycemia. Insulin pump use (β = 0.52, P < 0.001) and bolus insulin dose per kg per day (β = 0.46, P = 0.001) were independent predictors of time spent in hypoglycemia. Conclusions Carbohydrate intake is associated with time spent in euglycemia in patients with type 1 diabetes. PMID:26543542

  3. Reading-Related Literacy Activities of American Adults: Time Spent, Task Types, and Cognitive Skills Used

    ERIC Educational Resources Information Center

    White, Sheida; Chen, Jing; Forsyth, Barbara

    2010-01-01

    This article presents data on the types and duration of reading-related activities reported by a volunteer sample of 400 adults (demographically similar to the U.S. adult population age 20 and older in terms of race, ethnicity, education, and working status) in the 2005 Real-World Tasks Study. This diary study revealed that adults spent, on…

  4. Willingness-to-Pay to Avoid the Time Spent and Discomfort Associated with Screening Colonoscopy

    PubMed Central

    Jonas, Daniel E.; Russell, Louise B.; Chou, Jon; Pignone, Michael

    2014-01-01

    Background The screening colonoscopy process requires a considerable amount of time and some discomfort for patients. Objective We sought to use willingness-to-pay (WTP) to value the time required and the discomfort associated with screening colonoscopy. In addition, we aimed to explore some of the differences between and potential uses of the WTP and the human capital methods. Methods Subjects completed a diary recording time and a questionnaire including WTP questions to value the time and discomfort associated with colonoscopy. We also valued the elapsed time reported in the diaries (but not the discomfort) using the human capital method. Results 110 subjects completed the study. Mean WTP to avoid the time and discomfort was $263. Human capital values for elapsed time were greater. Linear regressions showed that WTP was influenced most by the difficulty of the preparation, which added $147 to WTP (p=0.03). Conclusions WTP values to avoid the time and discomfort associated with the screening colonoscopy process were substantially lower than most of the human capital values for elapsed time alone. The human capital method may overestimate the value of time in situations that involve an irregular, episodic series of time intervals, such as preparation for or recovery after colonoscopy. PMID:19725018

  5. The Influence of Time Spent in Outdoor Play on Daily and Aerobic Step Count in Costa Rican Children

    ERIC Educational Resources Information Center

    Morera Castro, Maria del Rocio

    2011-01-01

    The purpose of this study is to examine the influence of time spent in outdoor play (i.e., on weekday and weekend days) on daily (i.e., average step count) and aerobic step count (i.e., average moderate to vigorous physical activity [MVPA] during the weekdays and weekend days) in fifth grade Costa Rican children. It was hypothesized that: (a)…

  6. Breast Intensity-Modulated Radiation Therapy Reduces Time Spent With Acute Dermatitis for Women of All Breast Sizes During Radiation

    SciTech Connect

    Freedman, Gary M. Li Tianyu; Nicolaou, Nicos; Chen Yan; Ma, Charlie C.-M.; Anderson, Penny R.

    2009-07-01

    Purpose: To study the time spent with radiation-induced dermatitis during a course of radiation therapy for breast cancer in women treated with conventional or intensity-modulated radiation therapy (IMRT). Methods and Materials: The study population consisted of 804 consecutive women with early-stage breast cancer treated with breast-conserving surgery and radiation from 2001 to 2006. All patients were treated with whole-breast radiation followed by a boost to the tumor bed. Whole-breast radiation consisted of conventional wedged photon tangents (n = 405) earlier in the study period and mostly of photon IMRT (n = 399) in later years. All patients had acute dermatitis graded each week of treatment. Results: The breakdown of the cases of maximum acute dermatitis by grade was as follows: 3%, Grade 0; 34%, Grade 1; 61%, Grade 2; and 2%, Grade 3. The breakdown of cases of maximum toxicity by technique was as follows: 48%, Grade 0/1, and 52%, Grade 2/3, for IMRT; and 25%, Grade 0/1, and 75%, Grade 2/3, for conventional radiation therapy (p < 0.0001). The IMRT patients spent 82% of weeks during treatment with Grade 0/1 dermatitis and 18% with Grade 2/3 dermatitis, compared with 29% and 71% of patients, respectively, treated with conventional radiation (p < 0.0001). Furthermore, the time spent with Grade 2/3 toxicity was decreased in IMRT patients with small (p = 0.0015), medium (p < 0.0001), and large (p < 0.0001) breasts. Conclusions: Breast IMRT is associated with a significant decrease both in the time spent during treatment with Grade 2/3 dermatitis and in the maximum severity of dermatitis compared with that associated with conventional radiation, regardless of breast size.

  7. Time well spent: the duration of foster care and early adult labor market, educational, and health outcomes.

    PubMed

    Fallesen, Peter

    2013-12-01

    Individuals who spent time in foster care as children fare on average worse than non-placed peers in early adult life. Recent research on the effect of foster care placement on early adult life outcomes provides mixed evidence. Some studies suggest negative effects of foster care placement on early adult outcomes, others find null effects. This study shows that differences in the average duration of foster care stays explain parts of these discordant findings and then test how foster care duration shapes later life outcomes using administrative data on 7220 children. The children experienced different average durations of foster care because of differences in exposure to a reform. Later born cohorts spent on average 3 months longer in foster care than earlier born cohorts. Isolating exogenous variation in duration of foster care, the study finds positive effects of increased duration of foster care on income and labor market participation. PMID:24215947

  8. Time jitter versus additive noise in a game theory context

    NASA Astrophysics Data System (ADS)

    Zaidi, Abdellatif; Boyer, Remy; Duhamel, Pierre

    2005-03-01

    Imperfectly synchronized watermark communication is almost the most hostile watermark channel. A desynchronization attack can yield a very high probability of bit error rate by simply moving the watermark from elements it has been embedded in, inhibiting hence its reliable retrieval from the original. In this paper, we adress attacks that can be modelled by an Additive White Gaussian Noise and Jitter (AWGN&J) channel in a game theory context. The AWGN&J channel was initially introduced to model local time fluctuations in the context of magnetic recording media. This channel is first briefly presented and characterized in terms of induced objective and perceptual distorsions. Also, performance loss of the one-bit watermarking Spread-Spectrum based scheme over an AWGN&J channel is derived. Then, results are applied in a game theoretic context to answer some questions such as: (i) for a given distortion budget, and from the attacker point of view, what part should be allocated to the desynchronization, and what part should be allocated to the additive noise?, (ii) from the defender point of view, what is the worst distortion? and (iii) is there means to countermeasure the attacker (limit the amount of objective distorsion)?

  9. 19 CFR 201.14 - Computation of time, additional hearings, postponements, continuances, and extensions of time.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Computation of time, additional hearings, postponements, continuances, and extensions of time. 201.14 Section 201.14 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION Initiation and Conduct of Investigations § 201.14 Computation of time,...

  10. Combined Effects of Time Spent in Physical Activity, Sedentary Behaviors and Sleep on Obesity and Cardio-Metabolic Health Markers: A Novel Compositional Data Analysis Approach

    PubMed Central

    Chastin, Sebastien F. M.; Palarea-Albaladejo, Javier; Dontje, Manon L.; Skelton, Dawn A.

    2015-01-01

    The associations between time spent in sleep, sedentary behaviors (SB) and physical activity with health are usually studied without taking into account that time is finite during the day, so time spent in each of these behaviors are codependent. Therefore, little is known about the combined effect of time spent in sleep, SB and physical activity, that together constitute a composite whole, on obesity and cardio-metabolic health markers. Cross-sectional analysis of NHANES 2005–6 cycle on N = 1937 adults, was undertaken using a compositional analysis paradigm, which accounts for this intrinsic codependence. Time spent in SB, light intensity (LIPA) and moderate to vigorous activity (MVPA) was determined from accelerometry and combined with self-reported sleep time to obtain the 24 hour time budget composition. The distribution of time spent in sleep, SB, LIPA and MVPA is significantly associated with BMI, waist circumference, triglycerides, plasma glucose, plasma insulin (all p<0.001), and systolic (p<0.001) and diastolic blood pressure (p<0.003), but not HDL or LDL. Within the composition, the strongest positive effect is found for the proportion of time spent in MVPA. Strikingly, the effects of MVPA replacing another behavior and of MVPA being displaced by another behavior are asymmetric. For example, re-allocating 10 minutes of SB to MVPA was associated with a lower waist circumference by 0.001% but if 10 minutes of MVPA is displaced by SB this was associated with a 0.84% higher waist circumference. The proportion of time spent in LIPA and SB were detrimentally associated with obesity and cardiovascular disease markers, but the association with SB was stronger. For diabetes risk markers, replacing SB with LIPA was associated with more favorable outcomes. Time spent in MVPA is an important target for intervention and preventing transfer of time from LIPA to SB might lessen the negative effects of physical inactivity. PMID:26461112

  11. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  12. 19 CFR 210.6 - Computation of time, additional hearings, postponements, continuances, and extensions of time.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Computation of time, additional hearings, postponements, continuances, and extensions of time. 210.6 Section 210.6 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Rules of General Applicability §...

  13. Daily time spent indoors in German homes--baseline data for the assessment of indoor exposure of German occupants.

    PubMed

    Brasche, Sabine; Bischof, Wolfgang

    2005-01-01

    Comprehensive time-activity studies, for use as a basis for estimates of personal exposure, are not readily available in Germany. This analysis of time spent indoors at home is based on data from "Dampness and mould in homes" (2000/ 2001)--a study of about 12,000 persons living in 5530 randomly selected apartments and houses in Germany. The results show the mean times per day people in Germany spend in their homes, classified by gender, age group, building location, city size, region, building type, owner-occupier status, number of people at home, smoking and ventilation habits, moisture emission and ill health factors such as asthma, allergy and number of acute respiratory infections per year. The overall mean time spent at home, 15.7 h per, is in accordance with results from US-American (15.6 h/day) and Canadian (15.8 h/day) human activity surveys carried out in the nineties, as well as being consistent with the German Environmental Survey (1990/92) and a small German study in 1987. PMID:16078638

  14. Time/motion observations of reactor loading, transportation, and dry unloading of an oversized truck spent-fuel shipment

    SciTech Connect

    Lavender, J.C.; Hostick, C.J.; Wakeman, B.H.

    1988-01-01

    This paper presents actual time/motion data for an oversize truck spent-fuel shipment from its origin, Surry, Virginia to its destination, Idaho National Engineering Laboratory (INEL). These data include the receipt of the empty cask at the reactor, wet-loading the cask, over-the-road or in-transit data, and receipt and dry unloading of the shipping cask at the receiving facility. Occupational doses were recorded at the Surry Power Plant as well as at INEL, and public doses were calculated for the in-transit dose analysis. This shipment was one of a series performed in support of a demonstration and evaluation of dry storage at INEL. The oversized shipment consisted of a TN-8L shipping cask loaded with three 10-yr-old pressurized water reactor assemblies. The total distance traveled was {approx}2800 miles, requiring 62 h including stops. The time required to receive and inspect the empty shipping cask and wet-load and release the shipment at the reactor was {approx}14.1 h, and the time to receive the loaded cask, dry-transfer the spent fuel to the storage cask, and release the empty cask and trailer at the INEL facility was {approx}8.2 h.

  15. Association of Environment and Policy Characteristics on Children’s Moderate-to-Vigorous Physical Activity and Time Spent Sedentary in Afterschool Programs

    PubMed Central

    Ajja, Rahma; Clennin, Morgan N.; Weaver, R. Glenn; Moore, Justin B.; Huberty, Jennifer L.; Ward, Dianne S.; Pate, Russell R.; Beets, Michael W.

    2014-01-01

    Background Afterschool programs (ASPs) are an important setting in which to promote children’s physical activity. This study examines the association of environmental and policy characteristics on the moderate-to-vigorous physical activity (MVPA) and sedentary behavior of children attending ASPs. Methods A total of 1,302 children attending 20 ASPs across South Carolina wore accelerometers (ActiGraph GT3X+) for up to 4 non-consecutive days. Policy-level characteristics were evaluated using the Healthy Afterschool Program Index-Physical Activity (HAPI-PA) scale. Physical activity space was measured using a measuring wheel (indoor, ft2) and GIS (outdoor, acres). The structure (free-play or organized) of activity opportunities, was evaluated via direct observation. Time spent in MVPA and sedentary, both indoors and outdoors, was estimated using accelerometry. Results For every 5000ft2 of utilized indoor activity space an additional 2.4 and 3.3 minutes/day of sedentary behavior was observed among boys and girls, respectively. A higher ratio of free-play to organized play was associated with higher indoor sedentary behavior among boys and girls (3.9 minutes/day and 10.0 minutes/day, respectively). For every one acre of outdoor activity space used, an additional 2.7 minutes/day of MVPA was observed for boys. A higher free-play to organized play ratio was associated with higher outdoor MVPA for boys and girls (4.4 and 3.4 minutes/day increase, respectively). Policy characteristics were unrelated to MVPA levels and time spent sedentary. Conclusion Findings indicate that policies and the size of activity space had limited influence on MVPA and sedentary behavior, suggesting that programmatic structure may be a more effective option to improve MVPA levels of children attending ASPs. PMID:25251100

  16. Timing of Getter Material Addition in Cementitious Wasteforms

    NASA Astrophysics Data System (ADS)

    Lawter, A.; Qafoku, N. P.; Asmussen, M.; Neeway, J.; Smith, G. L.

    2015-12-01

    A cementitious waste form, Cast Stone, is being evaluated as a possible supplemental immobilization technology for the Hanford sites's low activity waste (LAW), which contains radioactive 99Tc and 129I, as part of the tank waste cleanup mission. Cast Stone is made of a dry blend 47% blast furnace slag, 45% fly ash, and 8% ordinary Portland cement, mixed with a low-activity waste (LAW). To improve the retention of Tc and/or I in Cast Stone, materials with a high affinity for Tc and/or I, termed "getters," can be added to provide a stable domain for the radionuclides of concern. Previous testing conducted with a variety of getters has identified Tin(II)-Apatite and Silver Exchanged Zeolite as promising candidates for Tc and I, respectively. Investigation into the sequence in which getters are added to Cast Stone was performed following two methods: 1) adding getters to the Cast Stone dry blend, and then mixing with liquid waste, and 2) adding getters to the liquid waste first, followed by addition of the Cast Stone dry blend. Cast Stone monolith samples were prepared with each method and leach tests, following EPA method 1315, were conducted in either distilled water or simulated vadose zone porewater for a period of up to 63 days. The leachate was analyzed for Tc, I, Na, NO3-, NO2- and Cr with ICP-MS, ICP-OES and ion chromatography and the results indicated that the Cast Stone with getter addition in the dry blend mix (method 1) has lower rates of Tc and I leaching. The mechanisms of radionuclide release from the Cast Stone were also investigated with a variety of solid phase characterization techniques of the monoliths before and after leaching, such as XRD, SEM/EDS, TEM/SAED and other spectroscopic techniques.

  17. Detection of continuous-time quaternion signals in additive noise

    NASA Astrophysics Data System (ADS)

    Navarro-Moreno, Jesús; Ruiz-Molina, Juan Carlos; Oya, Antonia; Quesada-Rubio, José M.

    2012-12-01

    Different kinds of quaternion signal detection problems in continuous-time by using a widely linear processing are dealt with. The suggested solutions are based on an extension of the Karhunen-Loève expansion to the quaternion domain which provides uncorrelated scalar real-valued random coefficients. This expansion presents the notable advantage of transforming the original four-dimensional eigen problem to a one-dimensional problem. Firstly, we address the problem of detecting a quaternion deterministic signal in quaternion Gaussian noise and a version of Pitcher's Theorem is given. Also the particular case of a general quaternion Wiener noise is studied and an extension of the Cameron-Martin formula is presented. Finally, the problem of detecting a quaternion random signal in quaternion white Gaussian noise is tackled. In such a case, it is shown that the detector depends on the quaternion widely linear estimator of the signal.

  18. The effect of food environments on fruit and vegetable intake as modified by time spent at home: a cross-sectional study

    PubMed Central

    Chum, Antony; Farrell, Eddie; Vaivada, Tyler; Labetski, Anna; Selvaratnam, Inthuja; Larsen, Kristian; Pinter, Theresa; O'Campo, Patricia

    2015-01-01

    Objective There is a growing body of research that investigates how the residential neighbourhood context relates to individual diet. However, previous studies ignore participants’ time spent in the residential environment and this may be a problem because time-use studies show that adults’ time-use pattern can significantly vary. To better understand the role of exposure duration, we designed a study to examine ‘time spent at home’ as a moderator to the residential food environment-diet association. Design Cross-sectional observational study. Settings City of Toronto, Ontario, Canada. Participants 2411 adults aged 25–65. Primary outcome measure Frequency of vegetable and fruit intake (VFI) per day. Results To examine how time spent at home may moderate the relationship between residential food environment and VFI, the full sample was split into three equal subgroups—short, medium and long duration spent at home. We detected significant associations between density of food stores in the residential food environment and VFI for subgroups that spend medium and long durations at home (ie, spending a mean of 8.0 and 12.3 h at home, respectively—not including sleep time), but no associations exist for people who spend the lowest amount of time at home (mean=4.7 h). Also, no associations were detected in analyses using the full sample. Conclusions Our study is the first to demonstrate that time spent at home may be an important variable to identify hidden population patterns regarding VFI. Time spent at home can impact the association between the residential food environment and individual VFI. PMID:26044756

  19. Direct Measurement of Initial Enrichment, Burn-up and Cooling Time of Spent Fuel Assembly with a Differential Die-Away Technique Based Instrument

    SciTech Connect

    Henzl, Vladimir; Swinhoe, Martyn T.; Tobin, Stephen J.

    2012-07-13

    An outline of this presentation of what a Differential Die-Away (DDA) instrument can do are: (1) Principle of operation of DDA instrument; (2) Determination of initial enrichment (IE) ({sigma} < 5%); (3) Determination of burn up (BU) ({sigma} {approx} 6%); (4) Determination of cooling time (CT) ({sigma} {approx} 20-50%); and (5) DDA instrument as a standalone device. DDA response (fresh fuel vs. spent fuel) is: (1) Fresh fuel => DDA response increases (die-away time is longer) with increasing fissile content; and (2) Spent fuel => DDA response decreases (die-away time is shorter) with higher burn-up (i.e. more neutron absorbers present).

  20. My Life with Adeno-Associated Virus: A Long Time Spent Studying a Short Genome

    PubMed Central

    2013-01-01

    My 45 years of studying the molecular biology of adeno-associated virus are recounted. Additional activities as a mentor, department chair, and medical school administrator are described, as are my activities in the public sphere, which involved national issues related to science policy and medical education. PMID:23781880

  1. Assessment of Body Mass Index, Sugar Sweetened Beverage Intake and Time Spent in Physical Activity of American Indian Children in Oklahoma.

    PubMed

    Dennison, Michelle E; Sisson, Susan B; Lora, Karina; Stephens, Lancer D; Copeland, Kenneth C; Caudillo, Cynthia

    2015-08-01

    American Indian (AI) children have a combined overweight and obesity prevalence of 53%. Behaviors that contribute to obesity, such as sugar sweetened beverage (SSB) intake and time spent in physical activity (PA), have been poorly explored in this population. The purpose of this study is to report body mass index (BMI), SSB intake, and time spent in PA of 7-to-13-year-old AI children who reside in rural and urban areas in Oklahoma. Cross-sectional survey study. Self-reported SSB intake in the last month, and time spent in PA were collected via questionnaires. Height and weight were professionally measured. The sample included 124 7-to-13-year-old AI children who attended a diabetes prevention summer camp in 2013. BMI percentile, overweight and obesity prevalence, SSB intake, time spent in PA, and number of participants meeting the Physical Activity Guidelines for Americans. Descriptive characteristics for BMI percentile, overweight and obesity, SSB intake, time spent in PA, and meeting PA recommendations were calculated using means, standard deviations, and frequencies. Independent t test and Chi square analyses were used to test for gender differences. Participants were 10.2 ± 1.5 years old and 57% female. Sixty-three percent were overweight or obese. Children consumed 309 ± 309 kcal/day of SSB and spent 4.4 ± 3.8 h per week in moderate-to-vigorous PA. Approximately 32% met the 2008 Physical Activity Guidelines for Americans. No gender differences were observed. The prevalence of overweight and obesity was higher than previously reported in a similar population, and higher than that of US children in the general population. SSB intake and physical activity levels were also found to be higher in this group than in the general population. PMID:25750107

  2. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations: Crew of three or... OPERATIONS Flight Time Limitations: Supplemental Operations § 121.523 Flight time limitations: Crew of three... hours before beginning flight duty, one half of the time spent in deadhead transportation must...

  3. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight time limitations: Crew of three or... OPERATIONS Flight Time Limitations: Supplemental Operations § 121.523 Flight time limitations: Crew of three... hours before beginning flight duty, one half of the time spent in deadhead transportation must...

  4. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight time limitations: Crew of three or... OPERATIONS Flight Time Limitations: Supplemental Operations § 121.523 Flight time limitations: Crew of three... hours before beginning flight duty, one half of the time spent in deadhead transportation must...

  5. Nurses' daily life: gender relations from the time spent in hospital1

    PubMed Central

    Pereira, Audrey Vidal

    2015-01-01

    Objective: to analyze the everyday life of nurses through the sexual work division as well as through interdependence relations and the time in hospital. Method: quanti-qualitative study, based on the Time Use Survey and in Norbert Elias's Configuration Theory of Interdependencies. Daily shifts distribution record, directed by 42 participants - with self-confrontation - by interviews which drew dialogues on subjective aspects of the everyday experiences related to use of time, based on a job at a university hospital. The theoretical intake that founded data analysis was based on concepts of conflicts of interest, power struggles, sexual work division and polychronic-monochronic concepts - whether the work environment demands multitasking nurses or not. Results: time records allowed to observe differences between the groups studied, useful to identify conflicts, tensions, power struggles and gender inequalities in interviewees' everyday affairs that do not only affect physical and mental health, but also their way of life. Conclusion: the analytical path pointed out the need for public policies that promote equity in gender relations, keeping at sight the exercise of plural discourses and tolerant stances capable to respect differences between individual and collective time. PMID:26487146

  6. Bullying Behavior, Parents' Work Hours and Early Adolescents' Perceptions of Time Spent with Parents

    ERIC Educational Resources Information Center

    Christie-Mizell, C. Andre; Keil, Jacqueline M.; Laske, Mary Therese; Stewart, Jennifer

    2011-01-01

    This research investigates the relationships among bullying behavior, mother's and father's work hours, and early adolescents' perceptions of whether they spend sufficient time with their parents. In cross-sectional models, we find maternal work hours are modestly associated with increases in bullying behavior. However, in more rigorous change…

  7. The Relation between the Time Mothers and Children Spent Together and the Children's Trait Emotional Intelligence

    ERIC Educational Resources Information Center

    Alegre, Albert

    2012-01-01

    Background: Parenting practices have been shown to predict children's emotional intelligence. The time that mothers and children spend in joint activity is an important aspect of the parent-child relationship, and it has been found to be influential in different domains of children's development. However, it has not been investigated in relation…

  8. The Relationship between Students' Small Group Activities, Time Spent on Self-Study, and Achievement

    ERIC Educational Resources Information Center

    Kamp, Rachelle J. A.; Dolmans, Diana H. J. M.; van Berkel, Henk J. M.; Schmidt, Henk G.

    2012-01-01

    The purpose of this study was to investigate the relationship between the contributions students make to the problem-based tutorial group process as observed by their peers, self-study time and achievement. To that end, the Maastricht Peer Activity Rating Scale was administered to students participating in Problem-Based Learning tutorial groups.…

  9. Variations in Teachers' Management of and Time Spent on Reading Instruction: Effects on Student Learning.

    ERIC Educational Resources Information Center

    Felsenthal, Helen; Kirsch, Irwin

    To determine if there was variability in scheduled and engaged time in reading among classrooms and in management style among teachers and to see if these factors accounted for differences on a standardized reading achievement measure, a study was conducted involving 13 fourth, fifth, and sixth grade reading classrooms. Pretest and posttest data…

  10. Lead Slowing-Down Spectrometry Time Spectral Analysis for Spent Fuel Assay: FY11 Status Report

    SciTech Connect

    Kulisek, Jonathan A.; Anderson, Kevin K.; Bowyer, Sonya M.; Casella, Andrew M.; Gesh, Christopher J.; Warren, Glen A.

    2011-09-30

    Developing a method for the accurate, direct, and independent assay of the fissile isotopes in bulk materials (such as used fuel) from next-generation domestic nuclear fuel cycles is a goal of the Office of Nuclear Energy, Fuel Cycle R&D, Material Protection and Control Technology (MPACT) Campaign. To meet this goal, MPACT supports a multi-institutional collaboration, of which PNNL is a part, to study the feasibility of Lead Slowing Down Spectroscopy (LSDS). This technique is an active nondestructive assay method that has the potential to provide independent, direct measurement of Pu and U isotopic masses in used fuel with an uncertainty considerably lower than the approximately 10% typical of today's confirmatory assay methods. This document is a progress report for FY2011 PNNL analysis and algorithm development. Progress made by PNNL in FY2011 continues to indicate the promise of LSDS analysis and algorithms applied to used fuel. PNNL developed an empirical model based on calibration of the LSDS to responses generated from well-characterized used fuel. The empirical model, which accounts for self-shielding effects using empirical basis vectors calculated from the singular value decomposition (SVD) of a matrix containing the true self-shielding functions of the used fuel assembly models. The potential for the direct and independent assay of the sum of the masses of 239Pu and 241Pu to within approximately 3% over a wide used fuel parameter space was demonstrated. Also, in FY2011, PNNL continued to develop an analytical model. Such efforts included the addition of six more non-fissile absorbers in the analytical shielding function and the non-uniformity of the neutron flux across the LSDS assay chamber. A hybrid analytical-empirical approach was developed to determine the mass of total Pu (sum of the masses of 239Pu, 240Pu, and 241Pu), which is an important quantity in safeguards. Results using this hybrid method were of approximately the same accuracy as the pure

  11. Does patient time spent viewing computer-tailored colorectal cancer screening materials predict patient-reported discussion of screening with providers?

    PubMed

    Sanders, Mechelle; Fiscella, Kevin; Veazie, Peter; Dolan, James G; Jerant, Anthony

    2016-08-01

    The main aim is to examine whether patients' viewing time on information about colorectal cancer (CRC) screening before a primary care physician (PCP) visit is associated with discussion of screening options during the visit. We analyzed data from a multi-center randomized controlled trial of a tailored interactive multimedia computer program (IMCP) to activate patients to undergo CRC screening, deployed in primary care offices immediately before a visit. We employed usage time information stored in the IMCP to examine the association of patient time spent using the program with patient-reported discussion of screening during the visit, adjusting for previous CRC screening recommendation and reading speed.On average, patients spent 33 minutes on the program. In adjusted analyses, 30 minutes spent using the program was associated with a 41% increase in the odds of the patient having a discussion with their PCP (1.04, 1.59, 95% CI). In a separate analysis of the tailoring modules; the modules encouraging adherence to the tailored screening recommendation and discussion with the patient's PCP yielded significant results. Other predictors of screening discussion included better self-reported physical health and increased patient activation. Time spent on the program predicted greater patient-physician discussion of screening during a linked visit.Usage time information gathered automatically by IMCPs offers promise for objectively assessing patient engagement around a topic and predicting likelihood of discussion between patients and their clinician. PMID:27343254

  12. The Role of Parental Support, Parental Monitoring, and Time Spent with Parents in Adolescent Academic Achievement in Iceland: A Structural Model of Gender Differences

    ERIC Educational Resources Information Center

    Kristjansson, Alfgeir Logi; Sigfusdottir, Inga Dora

    2009-01-01

    This study examines the relationship between parental support, parental monitoring, and time spent with parents and academic achievement among adolescent girls and boys in Iceland, a high-income per-capita Nordic country. The indirect role of school effort is also examined. Data of 7430 9th and 10th graders is analyzed in the study. Structural…

  13. The Influence of Instructional Climates on Time Spent in Management Tasks and Physical Activity of 2nd-Grade Students during Physical Education

    ERIC Educational Resources Information Center

    Logan, Samuel W.; Robinson, Leah E.; Webster, E. Kipling; Rudisill, Mary E.

    2015-01-01

    The purpose of this study is to determine the effect of two physical education (PE) instructional climates (mastery, performance) on the percentage of time students spent in a) moderate-to-vigorous physical activity (MVPA) and b) management tasks during PE in 2nd-grade students. Forty-eight 2nd graders (mastery, n = 23; performance, n = 25)…

  14. An influential factor for external radiation dose estimation for residents after the Fukushima Daiichi Nuclear Power Plant accident-time spent outdoors for residents in Iitate Village.

    PubMed

    Ishikawa, Tetsuo; Yasumura, Seiji; Ohtsuru, Akira; Sakai, Akira; Akahane, Keiichi; Yonai, Shunsuke; Sakata, Ritsu; Ozasa, Kotaro; Hayashi, Masayuki; Ohira, Tetsuya; Kamiya, Kenji; Abe, Masafumi

    2016-06-01

    Many studies have been conducted on radiation doses to residents after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Time spent outdoors is an influential factor for external dose estimation. Since little information was available on actual time spent outdoors for residents, different values of average time spent outdoors per day have been used in dose estimation studies on the FDNPP accident. The most conservative value of 24 h was sometimes used, while 2.4 h was adopted for indoor workers in the UNSCEAR 2013 report. Fukushima Medical University has been estimating individual external doses received by residents as a part of the Fukushima Health Management Survey by collecting information on the records of moves and activities (the Basic Survey) after the accident from each resident. In the present study, these records were analyzed to estimate an average time spent outdoors per day. As an example, in Iitate Village, its arithmetic mean was 2.08 h (95% CI: 1.64-2.51) for a total of 170 persons selected from respondents to the Basic Survey. This is a much smaller value than commonly assumed. When 2.08 h is used for the external dose estimation, the dose is about 25% (23-26% when using the above 95% CI) less compared with the dose estimated for the commonly used value of 8 h. PMID:27034103

  15. The Influence of Young Adults' Sex, Gender Role Orientation, Ordinal Position and Time Spent with Infants on Their Knowledge of Infant Development.

    ERIC Educational Resources Information Center

    Gullo, Dominic F; Paludi, Michele A.

    1989-01-01

    Identifies some characteristics of non at-risk prospective parents (239 young adults who were enrolled in introductory psychology classes) which may contribute to more accurate knowledge of infant development. Results are interpreted in terms of subjects' sex, gender role orientation, ordinal position in the family, and amount of time spent with…

  16. Lead Slowing-Down Spectrometry Time Spectral Analysis for Spent Fuel Assay: FY12 Status Report

    SciTech Connect

    Kulisek, Jonathan A.; Anderson, Kevin K.; Casella, Andrew M.; Siciliano, Edward R.; Warren, Glen A.

    2012-09-28

    .g. Pb stack size, neutron source location) of an LSDS for the purpose of assaying used fuel assemblies. Sensitivity studies were conducted that provide insight as to how the LSDS instrument can be improved by making it more sensitive to the center of the fuel assemblies. In FY2013, PNNL will continue efforts to develop and refine design requirements of an LSDS for the ultimate purpose of assaying used fuel assemblies. Future efforts will be directed toward more extensive experimental benchmarking of currently implemented time-spectra analysis algorithms.

  17. MONITORING SPENT NUCLEAR FUEL REPROCESSING CONDITIONS NON-DESTRUCTIVELY AND IN NEAR-REAL-TIME USING THE MULTI-ISOTOPE PROCESS (MIP) MONITOR

    SciTech Connect

    Orton, Christopher R.; Fraga, Carlos G.; Douglas, Matthew; Christensen, Richard; Schwantes, Jon M.

    2010-05-07

    Researchers from Pacific Northwest National Laboratory and The Ohio State University are working to develop a system for monitoring spent nuclear fuel reprocessing facilities on-line, nondestructively, and in near-real-time. This method, known as the Multi-Isotope Process (MIP) Monitor, is based upon the measurement of distribution patterns of a suite of indicator (radioactive) isotopes present within product and waste streams of a nuclear reprocessing facility. Signatures from these indicator isotopes are monitored on-line by gamma spectrometry and compared, in near-real-time, to patterns representing "normal" process conditions using multivariate pattern recognition software. By targeting gamma-emitting indicator isotopes, the MIP Monitor approach is compatible with the use of small, portable, high-resolution gamma detectors that may be easily deployed throughout an existing facility. In addition, utilization of a suite of radio-elements, including ones with multiple oxidation states, increases the likelihood that attempts to divert material via process manipulation would be detected. Proof-of-principle modeling exercises simulating changes in acid strength have been completed and the results are promising. Laboratory testing is currently under way and significant results are available. Recent experimental results, along with an overview of the method are presented.

  18. Reactivity and isotopic composition of spent PWR (pressurized-water-reactor) fuel as a function of initial enrichment, burnup, and cooling time

    SciTech Connect

    Cerne, S.P.; Hermann, O.W.; Westfall, R.M.

    1987-10-01

    This study presents the reactivity loss of spent PWR fuel due to burnup in terms of the infinite lattice multiplications factor, k/sub infinity/. Calculations were performed using the SAS2 and CSAS1 control modules of the SCALE system. The k/sub infinity/ values calculated for all combinations of six enrichments, seven burnups, and five cooling times. The results are presented as a primary function of enrichment in both tabular and graphic form. An equation has been developed to estimate the tabulated values of k/sub infinity/'s by specifying enrichment, cooling time, and burnup. Atom densities for fresh fuel, and spent fuel at cooling times of 2, 10, and 20 years are included. 13 refs., 8 figs., 8 tabs.

  19. US Spent (Used) Fuel Status, Management and Likely Directions- 12522

    SciTech Connect

    Jardine, Leslie J.

    2012-07-01

    As of 2010, the US has accumulated 65,200 MTU (42,300 MTU of PWR's; 23,000 MTU of BWR's) of spent (irradiated or used) fuel from 104 operating commercial nuclear power plants situated at 65 sites in 31 States and from previously shutdown commercial nuclear power plants. Further, the Department of Energy (DOE) has responsibility for an additional 2458 MTU of DOE-owned defense and non defense spent fuel from naval nuclear power reactors, various non-commercial test reactors and reactor demonstrations. The US has no centralized large spent fuel storage facility for either commercial spent fuel or DOE-owned spent fuel. The 65,200 MTU of US spent fuel is being safely stored by US utilities at numerous reactor sites in (wet) pools or (dry) metal or concrete casks. As of November 2010, the US had 63 'independent spent fuel storage installations' (or ISFSI's) licensed by the US Nuclear Regulatory Commission located at 57 sites in 33 states. Over 1400 casks loaded with spent fuel for dry storage are at these licensed ISFSI's; 47 sites are located at commercial reactor sites and 10 are located 'away' from a reactor (AFR's) site. DOE's small fraction of a 2458 MTU spent fuel inventory, which is not commercial spent fuel, is with the exception of 2 MTU, being stored at 4 sites in 4 States. The decades old US policy of a 'once through' fuel cycle with no recycle of spent fuel was set into a state of 'mass confusion or disruption' when the new US President Obama's administration started in early 2010 stopping the only US geologic disposal repository at the Yucca Mountain site in the State of Nevada from being developed and licensed. The practical result is that US nuclear power plant operators will have to continue to be responsible for managing and storing their own spent fuel for an indefinite period of time at many different sites in order to continue to generate electricity because there is no current US government plan, schedule or policy for taking possession of

  20. 22 CFR 1429.22 - Additional time after service by mail.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Additional time after service by mail. 1429.22 Section 1429.22 Foreign Relations FOREIGN SERVICE LABOR RELATIONS BOARD; FEDERAL LABOR RELATIONS AUTHORITY... MISCELLANEOUS AND GENERAL REQUIREMENTS General Requirements § 1429.22 Additional time after service by...

  1. 22 CFR 1429.22 - Additional time after service by mail.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Additional time after service by mail. 1429.22 Section 1429.22 Foreign Relations FOREIGN SERVICE LABOR RELATIONS BOARD; FEDERAL LABOR RELATIONS AUTHORITY... MISCELLANEOUS AND GENERAL REQUIREMENTS General Requirements § 1429.22 Additional time after service by...

  2. 22 CFR 1429.22 - Additional time after service by mail.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Additional time after service by mail. 1429.22 Section 1429.22 Foreign Relations FOREIGN SERVICE LABOR RELATIONS BOARD; FEDERAL LABOR RELATIONS AUTHORITY... MISCELLANEOUS AND GENERAL REQUIREMENTS General Requirements § 1429.22 Additional time after service by...

  3. 22 CFR 1429.22 - Additional time after service by mail.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Additional time after service by mail. 1429.22 Section 1429.22 Foreign Relations FOREIGN SERVICE LABOR RELATIONS BOARD; FEDERAL LABOR RELATIONS AUTHORITY... MISCELLANEOUS AND GENERAL REQUIREMENTS General Requirements § 1429.22 Additional time after service by...

  4. 22 CFR 1429.22 - Additional time after service by mail.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Additional time after service by mail. 1429.22 Section 1429.22 Foreign Relations FOREIGN SERVICE LABOR RELATIONS BOARD; FEDERAL LABOR RELATIONS AUTHORITY... MISCELLANEOUS AND GENERAL REQUIREMENTS General Requirements § 1429.22 Additional time after service by...

  5. How to Make Additional Time Matter: Integrating Individualized Tutorials into an Extended Day

    ERIC Educational Resources Information Center

    Kraft, Matthew A.

    2015-01-01

    Evidence on the effect of extending the school day is decidedly mixed because of the stark differences in how schools use additional time. In this paper, I focus narrowly on the effect of additional time used for individualized tutorials. In 2005, MATCH Charter Public High School integrated two hours of tutorials throughout an extended day. The…

  6. Time/motion observations and dose analysis of reactor loading, transportation, and dry unloading of an overweight truck spent fuel shipment

    SciTech Connect

    Hostick, C.J.; Lavender, J.C.; Wakeman, B.H.

    1992-04-01

    This document presents observed activity durations and radiation dose analyses for an overweight truck shipment of pressurized water reactor (PWR) spent fuel from the Surry Power Station in Virginia to the Idaho National Engineering Laboratory. The shipment consisted of a TN-8L shipping cask carrying three 9-year-old PWR spent fuel assemblies. Handling times and dose analyses for at-reactor activities were completed by Virginia Electric and Power Company (Virginia Power) personnel. Observations of in-transit and unloading activities were made by Pacific Northwest Laboratory (PNL) personnel, who followed the shipment for approximately 2800 miles and observed cask unloading activities. In-transit dose estimates were calculated using dose rate maps provided by Virginia Power for a fully loaded TN-8L shipping cask. The dose analysis for the cask unloading operations is based on the observations of PNL personnel.

  7. Time and dose assessment of barge shipment and at-reactor handling of a CASTOR V/21 spent fuel storage cask

    SciTech Connect

    Hostick, C.J. ); Lavender, J.C. ); Wakeman, B.H. )

    1992-04-01

    This report contains the results of a time/motion analysis and a radiation dose assessment made during the receipt from barge transport and the loading of CAst iron cask for Storage and Transport Of Radioactive material (CASTOR) V/21 storage casks with spent nuclear fuel at the Surry Power Station in Virginia during 1987. The study was a cooperative effort between Pacific Northwest Laboratory (PNL) and Virginia Electric and Power Company (Virginia Power), and was funded by the US Department of Energy (DOE) Transportation Program Office. In this study, cask handling activities were tracked at the Surry Power Station, tracing the transfer of the empty spent fuel storage cask from an ocean-going vessel to a barge for river transport through the activities required to place the loaded storage cask at an at-reactor storage location.

  8. Comparative analysis of LWR and FBR spent fuels for nuclear forensics evaluation

    NASA Astrophysics Data System (ADS)

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-01

    Some interesting issues are attributed to nuclide compositions of spent fuels from thermal reactors as well as fast reactors such as a potential to reuse as recycled fuel, and a possible capability to be manage as a fuel for destructive devices. In addition, analysis on nuclear forensics which is related to spent fuel compositions becomes one of the interesting topics to evaluate the origin and the composition of spent fuels from the spent fuel foot-prints. Spent fuel compositions of different fuel types give some typical spent fuel foot prints and can be estimated the origin of source of those spent fuel compositions. Some technics or methods have been developing based on some science and technological capability including experimental and modeling or theoretical aspects of analyses. Some foot-print of nuclear forensics will identify the typical information of spent fuel compositions such as enrichment information, burnup or irradiation time, reactor types as well as the cooling time which is related to the age of spent fuels. This paper intends to evaluate the typical spent fuel compositions of light water (LWR) and fast breeder reactors (FBR) from the view point of some foot prints of nuclear forensics. An established depletion code of ORIGEN is adopted to analyze LWR spent fuel (SF) for several burnup constants and decay times. For analyzing some spent fuel compositions of FBR, some coupling codes such as SLAROM code, JOINT and CITATION codes including JFS-3-J-3.2R as nuclear data library have been adopted. Enriched U-235 fuel composition of oxide type is used for fresh fuel of LWR and a mixed oxide fuel (MOX) for FBR fresh fuel. Those MOX fuels of FBR come from the spent fuels of LWR. Some typical spent fuels from both LWR and FBR will be compared to distinguish some typical foot-prints of SF based on nuclear forensic analysis.

  9. Comparative analysis of LWR and FBR spent fuels for nuclear forensics evaluation

    SciTech Connect

    Permana, Sidik; Suzuki, Mitsutoshi; Su'ud, Zaki

    2012-06-06

    Some interesting issues are attributed to nuclide compositions of spent fuels from thermal reactors as well as fast reactors such as a potential to reuse as recycled fuel, and a possible capability to be manage as a fuel for destructive devices. In addition, analysis on nuclear forensics which is related to spent fuel compositions becomes one of the interesting topics to evaluate the origin and the composition of spent fuels from the spent fuel foot-prints. Spent fuel compositions of different fuel types give some typical spent fuel foot prints and can be estimated the origin of source of those spent fuel compositions. Some technics or methods have been developing based on some science and technological capability including experimental and modeling or theoretical aspects of analyses. Some foot-print of nuclear forensics will identify the typical information of spent fuel compositions such as enrichment information, burnup or irradiation time, reactor types as well as the cooling time which is related to the age of spent fuels. This paper intends to evaluate the typical spent fuel compositions of light water (LWR) and fast breeder reactors (FBR) from the view point of some foot prints of nuclear forensics. An established depletion code of ORIGEN is adopted to analyze LWR spent fuel (SF) for several burnup constants and decay times. For analyzing some spent fuel compositions of FBR, some coupling codes such as SLAROM code, JOINT and CITATION codes including JFS-3-J-3.2R as nuclear data library have been adopted. Enriched U-235 fuel composition of oxide type is used for fresh fuel of LWR and a mixed oxide fuel (MOX) for FBR fresh fuel. Those MOX fuels of FBR come from the spent fuels of LWR. Some typical spent fuels from both LWR and FBR will be compared to distinguish some typical foot-prints of SF based on nuclear forensic analysis.

  10. 14 CFR 121.483 - Flight time limitations: Two pilots and one additional flight crewmember.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight time limitations: Two pilots and one... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Time Limitations: Flag Operations § 121.483 Flight time limitations: Two pilots and one additional...

  11. 14 CFR 121.483 - Flight time limitations: Two pilots and one additional flight crewmember.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations: Two pilots and one... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Time Limitations: Flag Operations § 121.483 Flight time limitations: Two pilots and one additional...

  12. 14 CFR 121.483 - Flight time limitations: Two pilots and one additional flight crewmember.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight time limitations: Two pilots and one... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Time Limitations: Flag Operations § 121.483 Flight time limitations: Two pilots and one additional...

  13. Bifurcated method and apparatus for floating point addition with decreased latency time

    DOEpatents

    Farmwald, Paul M.

    1987-01-01

    Apparatus for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  14. Beyond Traditional Sampling Synthesis: Real-Time Timbre Morphing Using Additive Synthesis

    NASA Astrophysics Data System (ADS)

    Haken, Lippold; Fitz, Kelly; Christensen, Paul

    Because of its theoretical advantage for making timbral manipulations, sine wave additive synthesis is an attractive alternative to sampling synthesis, which is currently the most popular method for real-time synthesizers. Nevertheless, until recently performers have seldom used additive synthesis because of the practical difficulty of accomplishing these timbral manipulations, which inherently require modification of large numbers of time-varying amplitude and frequency control functions.

  15. Temperature for Spent Fuel Dry Storage

    1992-07-13

    DATING (Determining Allowable Temperatures in Inert and Nitrogen Gases) calculates allowable initial temperatures for dry storage of light-water-reactor spent fuel and the cumulative damage fraction of Zircaloy cladding for specified initial storage temperature and stress and cooling histories. It is made available to ensure compliance with NUREG 10CFR Part 72, Licensing Requirements for the Storage of Spent Fuel in an Independent Spent Fuel Storage Installation (ISFSI). Although the program''s principal purpose is to calculate estimatesmore » of allowable temperature limits, estimates for creep strain, annealing fraction, and life fraction as a function of storage time are also provided. Equations for the temperature of spent fuel in inert and nitrogen gas storage are included explicitly in the code; in addition, an option is included for a user-specified cooling history in tabular form, and tables of the temperature and stress dependencies of creep-strain rate and creep-rupture time for Zircaloy at constant temperature and constant stress or constant ratio of stress/modulus can be created. DATING includes the GEAR package for the numerical solution of the rate equations and DPLOT for plotting the time-dependence of the calculated cumulative damage-fraction, creep strain, radiation damage recovery, and temperature decay.« less

  16. Temperature for Spent Fuel Dry Storage

    SciTech Connect

    1992-07-13

    DATING (Determining Allowable Temperatures in Inert and Nitrogen Gases) calculates allowable initial temperatures for dry storage of light-water-reactor spent fuel and the cumulative damage fraction of Zircaloy cladding for specified initial storage temperature and stress and cooling histories. It is made available to ensure compliance with NUREG 10CFR Part 72, Licensing Requirements for the Storage of Spent Fuel in an Independent Spent Fuel Storage Installation (ISFSI). Although the program''s principal purpose is to calculate estimates of allowable temperature limits, estimates for creep strain, annealing fraction, and life fraction as a function of storage time are also provided. Equations for the temperature of spent fuel in inert and nitrogen gas storage are included explicitly in the code; in addition, an option is included for a user-specified cooling history in tabular form, and tables of the temperature and stress dependencies of creep-strain rate and creep-rupture time for Zircaloy at constant temperature and constant stress or constant ratio of stress/modulus can be created. DATING includes the GEAR package for the numerical solution of the rate equations and DPLOT for plotting the time-dependence of the calculated cumulative damage-fraction, creep strain, radiation damage recovery, and temperature decay.

  17. The effect of silane addition timing on mixing processability and properties of silica reinforced rubber compound

    NASA Astrophysics Data System (ADS)

    Jeong, Hee-Hoon; Jin, Hyun-Ho; Ha, Sung-Ho; Jang, Suk-Hee; Kang, Yong-Gu; Han, Min-Hyun

    2016-03-01

    A series of experiments were performed to determine an optimum balance between processability and performance of a highly loaded silica compound. The experiments evaluated 4 different silane injection times. All mixing related to silane addition was conducted with a scaled up "Tandem" mixer line. With exception to silane addition timing, almost all operating conditions were controlled between experimental features. It was found that when the silane addition was introduced earlier in the mixing cycle both the reaction was more complete and the bound rubber content was higher. But processability indicators such as sheet forming and Mooney plasticity were negatively impacted. On the other hand, as silane injection was delayed to later in the mixing process the filler dispersion and good sheet forming was improved. However both the bound rubber content and Silane reaction completion were decreased. With the changes in silane addition time, the processability and properties of a silica compound can be controlled.

  18. The Role of Additional Processing Time and Lexical Constraint in Spoken Word Recognition

    ERIC Educational Resources Information Center

    LoCasto, Paul C.; Connine, Cynthia M.; Patterson, David

    2007-01-01

    Three phoneme monitoring experiments examined the manner in which additional processing time influences spoken word recognition. Experiment 1a introduced a version of the phoneme monitoring paradigm in which a silent interval is inserted prior to the word-final target phoneme. Phoneme monitoring reaction time decreased as the silent interval…

  19. Additional technician tasks and turnaround time in the clinical Stat laboratory

    PubMed Central

    Salinas, Maria; López-Garrigós, Maite; Flores, Emilio; Leiva-Salinas, Maria; Lillo, Rosa; Leiva-Salinas, Carlos

    2016-01-01

    Introduction Many additional tasks in the Stat laboratory (SL) increase the workload. It is necessary to control them because they can affect the service provided by the laboratory. Our aim is to calculate these tasks, study their evolution over a 10 year period, and compare turnaround times (TAT) in summer period to the rest of the year. Materials and methods Additional tasks were classified as “additional test request” and “additional sample”. We collected those incidences from the laboratory information system (LIS), and calculated their evolution over time. We also calculated the monthly TAT for troponin for Emergency department (ED) patients, as the difference between the verification and LIS registration time. A median time of 30 minutes was our indicator target. TAT results and tests workload in summer were compared to the rest of the year. Results Over a 10-year period, the technologists in the SL performed 51,385 additional tasks, a median of 475 per month. The workload was significantly higher during the summer (45,496 tests) than the rest of the year (44,555 tests) (P = 0.019). The troponin TAT did not show this variation between summer and the rest of the year, complying always with our 30 minutes indicator target. Conclusion The technicians accomplished a significant number of additional tasks, and the workload kept increasing over the period of 10 years. That did not affect the TAT results. PMID:27346970

  20. Cyclic additional optical true time delay for microwave beam steering with spectral filtering.

    PubMed

    Cao, Z; Lu, R; Wang, Q; Tessema, N; Jiao, Y; van den Boom, H P A; Tangdiongga, E; Koonen, A M J

    2014-06-15

    Optical true time delay (OTTD) is an attractive way to realize microwave beam steering (MBS) due to its inherent features of broadband, low-loss, and compactness. In this Letter, we propose a novel OTTD approach named cyclic additional optical true time delay (CAO-TTD). It applies additional integer delays of the microwave carrier frequency to achieve spectral filtering but without disturbing the spatial filtering (beam steering). Based on such concept, a broadband MBS scheme for high-capacity wireless communication is proposed, which allows the tuning of both spectral filtering and spatial filtering. The experimental results match well with the theoretical analysis. PMID:24978496

  1. Ultimate capacity of linear time-invariant bosonic channels with additive Gaussian noise

    NASA Astrophysics Data System (ADS)

    Roy Bardhan, Bhaskar; Shapiro, Jeffrey H.

    2016-03-01

    Fiber-optic communications are moving to coherent detection in order to increase their spectral efficiency, i.e., their channel capacity per unit bandwidth. At power levels below the threshold for significant nonlinear effects, the channel model for such operation a linear time-invariant filter followed by additive Gaussian noise is one whose channel capacity is well known from Shannon's noisy channel coding theorem. The fiber channel, however, is really a bosonic channel, meaning that its ultimate classical information capacity must be determined from quantum-mechanical analysis, viz. from the Holevo-Schumacher-Westmoreland (HSW) theorem. Based on recent results establishing the HSW capacity of a linear (lossy or amplifying) channel with additive Gaussian noise, we provide a general continuous-time result, namely the HSW capacity of a linear time-invariant (LTI) bosonic channel with additive Gaussian noise arising from a thermal environment. In particular, we treat quasi-monochromatic communication under an average power constraint through a channel comprised of a stable LTI filter that may be attenuating at all frequencies or amplifying at some frequencies and attenuating at others. Phase-insensitive additive Gaussian noise-associated with the continuous-time Langevin noise operator needed to preserve free-field commutator brackets is included at the filter output. We compare the resulting spectral efficiencies with corresponding results for heterodyne and homodyne detection over the same channel to assess the increased spectral efficiency that might be realized with optimum quantum reception.

  2. 14 CFR 121.483 - Flight time limitations: Two pilots and one additional flight crewmember.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Two pilots and one additional flight crewmember. 121.483 Section 121.483 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight...

  3. 14 CFR 121.483 - Flight time limitations: Two pilots and one additional flight crewmember.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Flight time limitations: Two pilots and one additional flight crewmember. 121.483 Section 121.483 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight...

  4. Learning style versus time spent studying and career choice: Which is associated with success in a combined undergraduate anatomy and physiology course?

    PubMed

    Farkas, Gary J; Mazurek, Ewa; Marone, Jane R

    2016-01-01

    The VARK learning style is a pedagogical focus in health care education. This study examines relationships of course performance vs. VARK learning preference, study time, and career plan among students enrolled in an undergraduate anatomy and physiology course at a large urban university. Students (n = 492) from the fall semester course completed a survey consisting of the VARK questionnaire, gender, academic year, career plans, and estimated hours spent per week in combined classroom and study time. Seventy-eight percent of students reported spending 15 or fewer hours per week studying. Study time and overall course score correlated significantly for the class as a whole (r = 0.111, P = 0.013), which was mainly due to lecture (r = 0.118, P = 0.009) performance. No significant differences were found among students grouped by learning styles. When corrected for academic year, overall course scores (mean ± SEM) for students planning to enter dentistry, medicine, optometry or pharmacy (79.89 ± 0.88%) were significantly higher than those of students planning to enter physical or occupational therapies (74.53 ± 1.15%; P = 0.033), as well as nurse/physician assistant programs (73.60 ± 1.3%; P = 0.040). Time spent studying was not significantly associated with either learning style or career choice. Our findings suggest that specific career goals and study time, not learning preferences, are associated with better performance among a diverse group of students in an undergraduate anatomy and physiology course. However, the extent to which prior academic preparation, cultural norms, and socioeconomic factors influenced these results requires further investigation. PMID:26301828

  5. Passivity and Passification of Memristor-Based Recurrent Neural Networks With Additive Time-Varying Delays.

    PubMed

    Rakkiyappan, Rajan; Chandrasekar, Arunachalam; Cao, Jinde

    2015-09-01

    This paper presents a new design scheme for the passivity and passification of a class of memristor-based recurrent neural networks (MRNNs) with additive time-varying delays. The predictable assumptions on the boundedness and Lipschitz continuity of activation functions are formulated. The systems considered here are based on a different time-delay model suggested recently, which includes additive time-varying delay components in the state. The connection between the time-varying delay and its upper bound is considered when estimating the upper bound of the derivative of Lyapunov functional. It is recognized that the passivity condition can be expressed in a linear matrix inequality (LMI) format and by using characteristic function method. For state feedback passification, it is verified that it is apathetic to use immediate or delayed state feedback. By constructing a Lyapunov-Krasovskii functional and employing Jensen's inequality and reciprocal convex combination technique together with a tighter estimation of the upper bound of the cross-product terms derived from the derivatives of the Lyapunov functional, less conventional delay-dependent passivity criteria are established in terms of LMIs. Moreover, second-order reciprocally convex approach is employed for deriving the upper bound for terms with inverses of squared convex parameters. The model based on the memristor with additive time-varying delays widens the application scope for the design of neural networks. Finally, pertinent examples are given to show the advantages of the derived passivity criteria and the significant improvement of the theoretical approaches. PMID:25415991

  6. Experimental model and analytic solution for real-time observation of vehicle's additional steer angle

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaolong; Li, Liang; Pan, Deng; Cao, Chengmao; Song, Jian

    2014-03-01

    The current research of real-time observation for vehicle roll steer angle and compliance steer angle(both of them comprehensively referred as the additional steer angle in this paper) mainly employs the linear vehicle dynamic model, in which only the lateral acceleration of vehicle body is considered. The observation accuracy resorting to this method cannot meet the requirements of vehicle real-time stability control, especially under extreme driving conditions. The paper explores the solution resorting to experimental method. Firstly, a multi-body dynamic model of a passenger car is built based on the ADAMS/Car software, whose dynamic accuracy is verified by the same vehicle's roadway test data of steady static circular test. Based on this simulation platform, several influencing factors of additional steer angle under different driving conditions are quantitatively analyzed. Then ɛ-SVR algorithm is employed to build the additional steer angle prediction model, whose input vectors mainly include the sensor information of standard electronic stability control system(ESC). The method of typical slalom tests and FMVSS 126 tests are adopted to make simulation, train model and test model's generalization performance. The test result shows that the influence of lateral acceleration on additional steer angle is maximal (the magnitude up to 1°), followed by the longitudinal acceleration-deceleration and the road wave amplitude (the magnitude up to 0.3°). Moreover, both the prediction accuracy and the calculation real-time of the model can meet the control requirements of ESC. This research expands the accurate observation methods of the additional steer angle under extreme driving conditions.

  7. New Stabilization for Dynamical System with Two Additive Time-Varying Delays

    PubMed Central

    Yang, Fan; Chen, Xiaozhou

    2014-01-01

    This paper provides a new delay-dependent stabilization criterion for systems with two additive time-varying delays. The novel functional is constructed, a tighter upper bound of the derivative of the Lyapunov functional is obtained. These results have advantages over some existing ones because the combination of the delay decomposition technique and the reciprocally convex approach. Two examples are provided to demonstrate the less conservatism and effectiveness of the results in this paper. PMID:24701159

  8. Predicting the Survival Time for Bladder Cancer Using an Additive Hazards Model in Microarray Data

    PubMed Central

    TAPAK, Leili; MAHJUB, Hossein; SADEGHIFAR, Majid; SAIDIJAM, Massoud; POOROLAJAL, Jalal

    2016-01-01

    Background: One substantial part of microarray studies is to predict patients’ survival based on their gene expression profile. Variable selection techniques are powerful tools to handle high dimensionality in analysis of microarray data. However, these techniques have not been investigated in competing risks setting. This study aimed to investigate the performance of four sparse variable selection methods in estimating the survival time. Methods: The data included 1381 gene expression measurements and clinical information from 301 patients with bladder cancer operated in the years 1987 to 2000 in hospitals in Denmark, Sweden, Spain, France, and England. Four methods of the least absolute shrinkage and selection operator, smoothly clipped absolute deviation, the smooth integration of counting and absolute deviation and elastic net were utilized for simultaneous variable selection and estimation under an additive hazards model. The criteria of area under ROC curve, Brier score and c-index were used to compare the methods. Results: The median follow-up time for all patients was 47 months. The elastic net approach was indicated to outperform other methods. The elastic net had the lowest integrated Brier score (0.137±0.07) and the greatest median of the over-time AUC and C-index (0.803±0.06 and 0.779±0.13, respectively). Five out of 19 selected genes by the elastic net were significant (P<0.05) under an additive hazards model. It was indicated that the expression of RTN4, SON, IGF1R and CDC20 decrease the survival time, while the expression of SMARCAD1 increase it. Conclusion: The elastic net had higher capability than the other methods for the prediction of survival time in patients with bladder cancer in the presence of competing risks base on additive hazards model. PMID:27114989

  9. Proof of Concept Experiments of the Multi-Isotope Process Monitor: An Online, Nondestructive, Near Real-Time Monitor for Spent Nuclear Fuel Reprocessing Facilities

    SciTech Connect

    Orton, Christopher R.; Fraga, Carlos G.; Christensen, Richard; Schwantes, Jon M.

    2012-04-21

    Operators, national regulatory agencies and the IAEA will require the development of advanced technologies to efficiently control and safeguard nuclear material at increasingly large-scale nuclear recycling facilities. Ideally, the envisioned technologies would be capable of non-destructive, near-real-time (NRT), autonomous process monitoring. This paper describes results from proof-of-principle experiments designed to test the Multi-Isotope Process (MIP) Monitor, a novel approach to safeguarding reprocessing facilities. The MIP Monitor combines the detection of intrinsic gamma ray signatures emitted from process solutions with multivariate analysis to detect off-normal conditions in process streams nondestructively and in NRT. Commercial spent nuclear fuel of various irradiation histories was dissolved and separated using a PUREX-based batch solvent extraction. Extractions were performed at various nitric acid concentrations to mimic both normal and off-normal industrial plant operating conditions. Principal Component Analysis (PCA) was applied to the simulated gamma spectra to investigate pattern variations as a function of acid concentration, burnup and cooling time. Partial Least Squares (PLS) regression was applied to attempt to quantify both the acid concentration and burnup of the dissolved spent fuel during the initial separation stage of recycle. The MIP Monitor demonstrated sensitivity to induced variations of acid concentration, including the distinction of {+-} 1.3 M variation from normal process conditions by way of PCA. Acid concentration was predicted using measurements from the organic extract and PLS resulting in predictions with <0.7 M relative error. Quantification of burnup levels from dissolved fuel spectra using PLS was demonstrated to be within 2.5% of previously measured values.

  10. Estimation of the lag time in a subsequent monomer addition model for fibril elongation.

    PubMed

    Shoffner, Suzanne K; Schnell, Santiago

    2016-08-01

    Fibrillogenesis, the production or development of protein fibers, has been linked to protein folding diseases. The progress curve of fibrils or aggregates typically takes on a sigmoidal shape with a lag phase, a rapid growth phase, and a final plateau regime. The study of the lag phase and the estimation of its critical timescale provide insight into the factors regulating the fibrillation process. However, methods to estimate a quantitative expression for the lag time rely on empirical expressions, which cannot connect the lag time to kinetic parameters associated with the reaction mechanisms of protein fibrillation. Here we introduce an approach for the estimation of the lag time using the governing rate equations of the elementary reactions of a subsequent monomer addition model for protein fibrillation as a case study. We show that the lag time is given by the sum of the critical timescales for each fibril intermediate in the subsequent monomer addition mechanism and therefore reveals causal connectivity between intermediate species. Furthermore, we find that single-molecule assays of protein fibrillation can exhibit a lag phase without a nucleation process, while dyes and extrinsic fluorescent probe bulk assays of protein fibrillation do not exhibit an observable lag phase during template-dependent elongation. Our approach could be valuable for investigating the effects of intrinsic and extrinsic factors to the protein fibrillation reaction mechanism and provides physicochemical insights into parameters regulating the lag phase. PMID:27250246

  11. Additional Nitrogen Fertilization at Heading Time of Rice Down-Regulates Cellulose Synthesis in Seed Endosperm

    PubMed Central

    Midorikawa, Keiko; Kuroda, Masaharu; Terauchi, Kaede; Hoshi, Masako; Ikenaga, Sachiko; Ishimaru, Yoshiro; Abe, Keiko; Asakura, Tomiko

    2014-01-01

    The balance between carbon and nitrogen is a key determinant of seed storage components, and thus, is of great importance to rice and other seed-based food crops. To clarify the influence of the rhizosphere carbon/nitrogen balance during the maturation stage of several seed components, transcriptome analysis was performed on the seeds from rice plants that were provided additional nitrogen fertilization at heading time. As a result, it was assessed that genes associated with molecular processes such as photosynthesis, trehalose metabolism, carbon fixation, amino acid metabolism, and cell wall metabolism were differentially expressed. Moreover, cellulose and sucrose synthases, which are involved in cellulose synthesis, were down-regulated. Therefore, we compared cellulose content of mature seeds that were treated with additional nitrogen fertilization with those from control plants using calcofluor staining. In these experiments, cellulose content in endosperm from plants receiving additional nitrogen fertilization was less than that in control endosperm. Other starch synthesis-related genes such as starch synthase 1, starch phosphorylase 2, and branching enzyme 3 were also down-regulated, whereas some α-amylase and β-amylase genes were up-regulated. On the other hand, mRNA expression of amino acid biosynthesis-related molecules was up-regulated. Moreover, additional nitrogen fertilization caused accumulation of storage proteins and up-regulated Cys-poor prolamin mRNA expression. These data suggest that additional nitrogen fertilization at heading time changes the expression of some storage substance-related genes and reduces cellulose levels in endosperm. PMID:24905454

  12. A Modified Time-Delay Addition Method to Extract Resistive Leakage Current of MOSA

    NASA Astrophysics Data System (ADS)

    Khodsuz, Masume; Mirzaie, Mohammad

    2015-06-01

    Metal oxide surge arresters are one of the most important equipment for power system protection against switching and lightning over-voltages. High-energy stresses and environmental features are the main factors which degrade surge arresters. In order to verify surge arresters good condition, their monitoring is necessary. The majority of surge arrester monitoring techniques is based on total leakage current decomposition of their capacitive and resistive components. This paper introduces a new approach based on time-delay addition method to extract the resistive current from the total leakage current without measuring voltage signal. Surge arrester model for calculating leakage current has been performed in ATP-EMTP. In addition, the signal processing has been done using MATLAB software. To show the accuracy of the proposed method, experimental tests have been performed to extract resistive leakage current by the proposed method.

  13. Intermodal transportation of spent fuel

    SciTech Connect

    Elder, H.K.

    1983-09-01

    Concepts for transportation of spent fuel in rail casks from nuclear power plant sites with no rail service are under consideration by the US Department of Energy in the Commercial Spent Fuel Management program at the Pacific Northwest Laboratory. This report identifies and evaluates three alternative systems for intermodal transfer of spent fuel: heavy-haul truck to rail, barge to rail, and barge to heavy-haul truck. This report concludes that, with some modifications and provisions for new equipment, existing rail and marine systems can provide a transportation base for the intermodal transfer of spent fuel to federal interim storage facilities. Some needed land transportation support and loading and unloading equipment does not currently exist. There are insufficient shipping casks available at this time, but the industrial capability to meet projected needs appears adequate.

  14. Winter-time CO2 addition in high rate algal mesocosms for enhanced microalgal performance.

    PubMed

    Sutherland, Donna L; Montemezzani, Valerio; Mehrabadi, Abbas; Craggs, Rupert J

    2016-02-01

    Carbon limitation in domestic wastewater high rate algal ponds is thought to constrain microalgal photo-physiology and productivity and CO2 augmentation is often used to overcome this limitation in summer. However, the implications of carbon limitation during winter are poorly understood. This paper investigates the effects of 0.5%, 2%, 5% and 10% CO2 addition on the winter-time performance of wastewater microalgae in high rate algal mesocosms. Performance was measured in terms of light absorption, photosynthetic efficiency, biomass production and nutrient removal rates, along with community composition. Varying percentage CO2 addition and associated change in culture pH resulted in 3 distinct microalgal communities. Light absorption by the microalgae increased by up to 144% with CO2 addition, while a reduction in the package effect meant that there was less internal self-shading thereby increasing the efficiency of light absorption. Carbon augmentation increased the maximum rate of photosynthesis by up to 172%, which led to increased microalgal biovolume by up to 181% and an increase in total organic biomass for all treatments except 10% CO2. While 10% CO2 improved light absorption and photosynthesis this did not translate to enhanced microalgal productivity. Increased microalgal productivity with CO2 addition did not result in increased dissolved nutrient (nitrogen and phosphorus) removal. This experiment demonstrated that winter-time carbon augmentation up to 5% CO2 improved microalgal light absorption and utilisation, which ultimately increased microalgal biomass and is likely to enhance total annual microalgal areal productivity in HRAPs. PMID:26707731

  15. State to State and Charged Particle Kinetic Modeling of Time Filtering and Cs Addition

    SciTech Connect

    Capitelli, M.; Gorse, C.; Longo, S.; Diomede, P.; Pagano, D.

    2007-08-10

    We present here an account on the progress of kinetic simulation of non equilibrium plasmas in conditions of interest for negative ion production by using the 1D Bari code for hydrogen plasma simulation. The model includes the state to state kinetics of the vibrational level population of hydrogen molecules, plus a PIC/MCC module for the multispecies dynamics of charged particles. In particular we present new results for the modeling of two issues of great interest: the time filtering and the Cs addition via surface coverage.

  16. Complete positivity, finite-temperature effects, and additivity of noise for time-local qubit dynamics

    NASA Astrophysics Data System (ADS)

    Lankinen, Juho; Lyyra, Henri; Sokolov, Boris; Teittinen, Jose; Ziaei, Babak; Maniscalco, Sabrina

    2016-05-01

    We present a general model of qubit dynamics which entails pure dephasing and dissipative time-local master equations. This allows us to describe the combined effect of thermalization and dephasing beyond the usual Markovian approximation. We investigate the complete positivity conditions and introduce a heuristic model that is always physical and provides the correct Markovian limit. We study the effects of temperature on the non-Markovian behavior of the system and show that the noise additivity property discussed by Yu and Eberly [Phys. Rev. Lett. 97, 140403 (2006), 10.1103/PhysRevLett.97.140403] holds beyond the Markovian limit.

  17. Analysis of Time to Event Outcomes in Randomized Controlled Trials by Generalized Additive Models

    PubMed Central

    Argyropoulos, Christos; Unruh, Mark L.

    2015-01-01

    Background Randomized Controlled Trials almost invariably utilize the hazard ratio calculated with a Cox proportional hazard model as a treatment efficacy measure. Despite the widespread adoption of HRs, these provide a limited understanding of the treatment effect and may even provide a biased estimate when the assumption of proportional hazards in the Cox model is not verified by the trial data. Additional treatment effect measures on the survival probability or the time scale may be used to supplement HRs but a framework for the simultaneous generation of these measures is lacking. Methods By splitting follow-up time at the nodes of a Gauss Lobatto numerical quadrature rule, techniques for Poisson Generalized Additive Models (PGAM) can be adopted for flexible hazard modeling. Straightforward simulation post-estimation transforms PGAM estimates for the log hazard into estimates of the survival function. These in turn were used to calculate relative and absolute risks or even differences in restricted mean survival time between treatment arms. We illustrate our approach with extensive simulations and in two trials: IPASS (in which the proportionality of hazards was violated) and HEMO a long duration study conducted under evolving standards of care on a heterogeneous patient population. Findings PGAM can generate estimates of the survival function and the hazard ratio that are essentially identical to those obtained by Kaplan Meier curve analysis and the Cox model. PGAMs can simultaneously provide multiple measures of treatment efficacy after a single data pass. Furthermore, supported unadjusted (overall treatment effect) but also subgroup and adjusted analyses, while incorporating multiple time scales and accounting for non-proportional hazards in survival data. Conclusions By augmenting the HR conventionally reported, PGAMs have the potential to support the inferential goals of multiple stakeholders involved in the evaluation and appraisal of clinical trial

  18. Off-Stream Watering Systems and Partial Barriers as a Strategy to Maximize Cattle Production and Minimize Time Spent in the Riparian Area

    PubMed Central

    Rawluk, Ashley A.; Crow, Gary; Legesse, Getahun; Veira, Douglas M.; Bullock, Paul R.; González, Luciano A.; Dubois, Melanie; Ominski, Kim H.

    2014-01-01

    Simple Summary The implementation of off-stream waterers (OSW) may reduce the amount of time cattle spend in riparian areas, thus minimizing impacts such as removal of vegetation, soil compaction, and deterioration in water quality. Furthermore, when used with natural barriers as a partial exclusion method, these management strategies may offer a cost-effective alternative to completely excluding cattle via streambank fencing. This study was conducted to determine the impact of OSW and barriers on animal performance and watering behavior. The presence of OSW had no significant effect on cow and calf weights averaged over the grazing season. Although the results were not consistent over the periods and locations, the data provided some indication of the efficacy of the natural barriers on deterring cattle from the riparian area. Cattle watered at the OSW when available, but they did not use the OSW exclusively. The observed inconsistency may, in part, be attributed to the environmental conditions present during this field trial. Abstract A study was conducted in 2009 at two locations in Manitoba (Killarney and Souris), Canada to determine the impact of off-stream waterers (OSW) with or without natural barriers on (i) amount of time cattle spent in the 10 m buffer created within the riparian area, referred to as the riparian polygon (RP), (ii) watering location (OSW or stream), and (iii) animal performance measured as weight gain. This study was divided into three 28-day periods over the grazing season. At each location, the pasture—which ranged from 21.0 ha to 39.2 ha in size—was divided into three treatments: no OSW nor barriers (1CONT), OSW with barriers along the stream bank to deter cattle from watering at the stream (2BARR), and OSW without barriers (3NOBARR). Cattle in 2BARR spent less time in the RP in Periods 1 (p = 0.0002), 2 (p = 0.1116), and 3 (p < 0.0001) at the Killarney site compared to cattle in 3NOBARR at the same site. Cattle in 2BARR at the

  19. Time and Money Spent on the Mass Media in an Age of New Communication Technologies: A Market Study.

    ERIC Educational Resources Information Center

    Ogan, Christine L.; Kelly, James D.

    A study surveyed 276 residents of Indianapolis, Indiana to determine how the people might be changing media use and spending habits in a time of growing interest in video cassette recorders (VCRs), backyard satellite dishes, pay-TV, and personal computers. Questions were designed to determine the degree to which people would buy into the new…

  20. The Cell Cycle: An Activity Using Paper Plates to Represent Time Spent in Phases of the Cell Cycle

    ERIC Educational Resources Information Center

    Scherer, Yvette D.

    2014-01-01

    In this activity, students are given the opportunity to combine skills in math and geometry for a biology lesson in the cell cycle. Students utilize the data they collect and analyze from an online onion-root-tip activity to create a paper-plate time clock representing a 24-hour cell cycle. By dividing the paper plate into appropriate phases of…

  1. Toward a Deterministic Polynomial Time Algorithm with Optimal Additive Query Complexity

    NASA Astrophysics Data System (ADS)

    Bshouty, Nader H.; Mazzawi, Hanna

    In this paper, we study two combinatorial search problems: The coin weighing problem with a spring scale (also known as the vector reconstructing problem using additive queries) and the problem of reconstructing weighted graphs using additive queries. Suppose we are given n identical looking coins. Suppose that m out of the n coins are counterfeit and the rest are authentic. Assume that we are allowed to weigh subsets of coins with a spring scale. It is known that the optimal number of weighing for identifying the counterfeit coins and their weights is at least Ω(mlog n/log m). We give a deterministic polynomial time adaptive algorithm for identifying the counterfeit coins and their weights using O(mlog n/log m+ mlog log m) weighings, assuming that the weight of the counterfeit coins are greater than the weight of the authentic coin. This algorithm is optimal when m ≤ n c/loglogn , where c is any constant. Also our weighing complexity is within loglogm times the optimal complexity for all m.

  2. Identifiability of Additive, Time-Varying Actuator and Sensor Faults by State Augmentation

    NASA Technical Reports Server (NTRS)

    Upchurch, Jason M.; Gonzalez, Oscar R.; Joshi, Suresh M.

    2014-01-01

    Recent work has provided a set of necessary and sucient conditions for identifiability of additive step faults (e.g., lock-in-place actuator faults, constant bias in the sensors) using state augmentation. This paper extends these results to an important class of faults which may affect linear, time-invariant systems. In particular, the faults under consideration are those which vary with time and affect the system dynamics additively. Such faults may manifest themselves in aircraft as, for example, control surface oscillations, control surface runaway, and sensor drift. The set of necessary and sucient conditions presented in this paper are general, and apply when a class of time-varying faults affects arbitrary combinations of actuators and sensors. The results in the main theorems are illustrated by two case studies, which provide some insight into how the conditions may be used to check the theoretical identifiability of fault configurations of interest for a given system. It is shown that while state augmentation can be used to identify certain fault configurations, other fault configurations are theoretically impossible to identify using state augmentation, giving practitioners valuable insight into such situations. That is, the limitations of state augmentation for a given system and configuration of faults are made explicit. Another limitation of model-based methods is that there can be large numbers of fault configurations, thus making identification of all possible configurations impractical. However, the theoretical identifiability of known, credible fault configurations can be tested using the theorems presented in this paper, which can then assist the efforts of fault identification practitioners.

  3. HFIR spent fuel management alternatives

    SciTech Connect

    Begovich, J.M.; Green, V.M.; Shappert, L.B.; Lotts, A.L.

    1992-10-15

    The High Flux Isotope Reactor (HFIR) at Martin Marietta Energy Systems` Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel to Savannah River Site (SRS) for reprocessing since 1985. The HFIR storage pools are expected to fill up in the February 1994 to February 1995 time frame. If a management altemative to existing HFIR pool storage is not identified and implemented before the HFIR pools are full, the HFIR will be forced to shut down. This study investigated several alternatives for managing the HFIR spent fuel, attempting to identify options that could be implemented before the HFIR pools are full. The options investigated were: installing a dedicated dry cask storage facility at ORNL, increasing HFIR pool storage capacity by clearing the HFIR pools of debris and either close-packing or stacking the spent fuel elements, storing the spent fuel at another ORNL pool, storing the spent fuel in one or more hot cells at ORNL, and shipping the spent fuel offsite for reprocessing or storage elsewhere.

  4. HFIR spent fuel management alternatives

    SciTech Connect

    Begovich, J.M.; Green, V.M.; Shappert, L.B.; Lotts, A.L.

    1992-10-15

    The High Flux Isotope Reactor (HFIR) at Martin Marietta Energy Systems' Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel to Savannah River Site (SRS) for reprocessing since 1985. The HFIR storage pools are expected to fill up in the February 1994 to February 1995 time frame. If a management altemative to existing HFIR pool storage is not identified and implemented before the HFIR pools are full, the HFIR will be forced to shut down. This study investigated several alternatives for managing the HFIR spent fuel, attempting to identify options that could be implemented before the HFIR pools are full. The options investigated were: installing a dedicated dry cask storage facility at ORNL, increasing HFIR pool storage capacity by clearing the HFIR pools of debris and either close-packing or stacking the spent fuel elements, storing the spent fuel at another ORNL pool, storing the spent fuel in one or more hot cells at ORNL, and shipping the spent fuel offsite for reprocessing or storage elsewhere.

  5. Chemical composition, plant secondary metabolites, and minerals of green and black teas and the effect of different tea-to-water ratios during their extraction on the composition of their spent leaves as potential additives for ruminants.

    PubMed

    Ramdani, Diky; Chaudhry, Abdul Shakoor; Seal, Chris J

    2013-05-22

    This study characterized the chemical composition of green and black teas as well as their spent tea leaves (STL) following boiling in water with different tea-to-water ratios. The green and black tea leaves had statistically similar (g/kg dry matter (DM), unless stated otherwise) DM (937 vs 942 g/kg sample), crude protein (240 vs 242), and ash (61.8 vs 61.4), but green tea had significantly higher (g/kg DM) total phenols (231 vs 151), total tannins (204 vs 133), condensed tannins (176 vs 101), and total saponins (276 vs 86.1) and lower neutral detergent fiber (254 vs 323) and acid detergent fiber (211 vs 309) than the black tea leaves. There was no significant difference between the green and black tea leaves for most mineral components except Mn, which was significantly higher in green tea leaves, and Na and Cu, which were significantly higher in black tea leaves. A higher tea-to-water ratio during extraction significantly reduced the loss of soluble compounds into water and hence yielded more nutrient-rich STL. On the basis of these analyses it appears that the green and black tea leaves alongside their STL have the potential for use as sources of protein, fiber, secondary metabolites, and minerals in ruminant diets. The presence of high levels of plant secondary metabolites in either tea leaves or their STL suggests that they may have potential for use as natural additives in ruminant diets. PMID:23621359

  6. Modelling of time resolved and long contact time dissolution studies of spent nuclear fuel in 10 mM carbonate solution A comparison between two different models and experimental data

    NASA Astrophysics Data System (ADS)

    Eriksen, Trygve E.; Jonsson, Mats; Merino, Juan

    2008-04-01

    Using two different models, radiation induced dissolution of spent UO 2 fuel has been simulated. One of the models is conventional homogeneous radiolysis simulations where two different geometrical constraints were used and the second model is the recently developed steady-state model. The results of the simulations are compared to each other and to experimental results from spent fuel leaching experiments performed in carbonate containing aqueous solution under Ar-atmosphere. The influence of radiolytically produced H 2 is incorporated (on the basis of a recently suggested mechanism) in both models and this reproduces the experimentally observed inhibition of spent fuel dissolution fairly well. The conventional radiolysis model reproduces the experimental concentrations of the radiolysis products H 2 and O 2 very well while it fails to reproduce the experimental H 2O 2 concentration. The reasons for this are discussed. The general trend in uranium concentration as a function of time is reproduced by both the conventional radiolysis model and the steady-state model. The conventional radiolysis model (in which the radiation dose is homogeneously distributed in the whole liquid volume) underestimates the uranium concentration while the steady-state model, which represents the worst case scenario, overestimates the concentrations to some extent. When applying the conventional radiolysis model, assuming that all the radiation energy is deposited within 40 μm from the fuel surface, the uranium concentrations during the initial part of the experiments are reproduced quantitatively. The differences between the models and the applicability of the models are discussed in some detail.

  7. RNA polymerase pausing regulates translation initiation by providing additional time for TRAP-RNA interaction.

    PubMed

    Yakhnin, Alexander V; Yakhnin, Helen; Babitzke, Paul

    2006-11-17

    RNA polymerase (RNAP) pause sites have been identified in several prokaryotic genes. Although the presumed biological function of RNAP pausing is to allow synchronization of RNAP position with regulatory factor binding and/or RNA folding, a direct causal link between pausing and changes in gene expression has been difficult to establish. RNAP pauses at two sites in the Bacillus subtilis trpEDCFBA operon leader. Pausing at U107 and U144 participates in transcription attenuation and trpE translation control mechanisms, respectively. Substitution of U144 caused a substantial pausing defect in vitro and in vivo. These mutations led to increased trp operon expression that was suppressed by overproduction of TRAP, indicating that pausing at U144 provides additional time for TRAP to bind to the nascent transcript and promote formation of an RNA structure that blocks translation of trpE. These results establish that pausing is capable of playing a role in regulating translation in bacteria. PMID:17114058

  8. Determining initial enrichment, burnup, and cooling time of pressurized-water reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    DOE PAGESBeta

    Favalli, Andrea; Vo, D.; Grogan, Brandon R.; Jansson, Peter; Liljenfeldt, Henrik; Mozin, Vladimir; Schwalbach, P.; Sjoland, A.; Tobin, Stephen J.; Trellue, Holly; et al

    2016-02-26

    The purpose of the Next Generation Safeguards Initiative (NGSI)–Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuelmore » assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity’s behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. Furthermore, the results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.« less

  9. Determining initial enrichment, burnup, and cooling time of pressurized-water-reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

    NASA Astrophysics Data System (ADS)

    Favalli, A.; Vo, D.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S. J.; Trellue, H.; Vaccaro, S.

    2016-06-01

    The purpose of the Next Generation Safeguards Initiative (NGSI)-Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity's behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

  10. A Comparison of Variable Time Compressed Speech and Normal Rate Speech Based on Time Spent and Performance in a Course Taught by Self-Instructional Methods.

    ERIC Educational Resources Information Center

    Short, Sarah Harvey

    The purpose of this study was to determine with precise measurements of time and carefully constructed posttests whether sighted students in a college course would save time and achieve higher scores when listening to cognitive information using variable time compressors as compared with students listening using normal speed tape recorders. The…

  11. Is It Time Well Spent? The Relationship between Time Management Behaviours, Perceived Effectiveness and Work-Related Morale and Distress in a University Context

    ERIC Educational Resources Information Center

    Kearns, Hugh; Gardiner, Maria

    2007-01-01

    Despite the high "guru-factor" in time management, few claims have been subjected to empirical investigation. This study tests the claims that people who manage their time well perceive themselves to be more effective and feel less stressed. University staff and students were utilized to investigate the relationship between time management related…

  12. Time-Resolved In Situ Measurements During Rapid Alloy Solidification: Experimental Insight for Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    McKeown, Joseph T.; Zweiacker, Kai; Liu, Can; Coughlin, Daniel R.; Clarke, Amy J.; Baldwin, J. Kevin; Gibbs, John W.; Roehling, John D.; Imhoff, Seth D.; Gibbs, Paul J.; Tourret, Damien; Wiezorek, Jörg M. K.; Campbell, Geoffrey H.

    2016-03-01

    Additive manufacturing (AM) of metals and alloys is becoming a pervasive technology in both research and industrial environments, though significant challenges remain before widespread implementation of AM can be realized. In situ investigations of rapid alloy solidification with high spatial and temporal resolutions can provide unique experimental insight into microstructure evolution and kinetics that are relevant for AM processing. Hypoeutectic thin-film Al-Cu and Al-Si alloys were investigated using dynamic transmission electron microscopy to monitor pulsed-laser-induced rapid solidification across microsecond timescales. Solid-liquid interface velocities measured from time-resolved images revealed accelerating solidification fronts in both alloys. The observed microstructure evolution, solidification product, and presence of a morphological instability at the solid-liquid interface in the Al-4 at.%Cu alloy are related to the measured interface velocities and small differences in composition that affect the thermophysical properties of the alloys. These time-resolved in situ measurements can inform and validate predictive modeling efforts for AM.

  13. Time-Resolved In Situ Measurements During Rapid Alloy Solidification: Experimental Insight for Additive Manufacturing

    DOE PAGESBeta

    McKeown, Joseph T.; Zweiacker, Kai; Liu, Can; Coughlin, Daniel R.; Clarke, Amy J.; Baldwin, J. Kevin; Gibbs, John W.; Roehling, John D.; Imhoff, Seth D.; Gibbs, Paul J.; et al

    2016-01-27

    In research and industrial environments, additive manufacturing (AM) of metals and alloys is becoming a pervasive technology, though significant challenges remain before widespread implementation of AM can be realized. In situ investigations of rapid alloy solidification with high spatial and temporal resolutions can provide unique experimental insight into microstructure evolution and kinetics that are relevant for AM processing. Hypoeutectic thin-film Al–Cu and Al–Si alloys were investigated using dynamic transmission electron microscopy to monitor pulsed-laser-induced rapid solidification across microsecond timescales. Solid–liquid interface velocities measured from time-resolved images revealed accelerating solidification fronts in both alloys. We observed microstructure evolution, solidification product, andmore » presence of a morphological instability at the solid–liquid interface in the Al–4 at.%Cu alloy are related to the measured interface velocities and small differences in composition that affect the thermophysical properties of the alloys. These time-resolved in situ measurements can inform and validate predictive modeling efforts for AM.« less

  14. Regulation of Soil Microbial Carbon-use Efficiency by Soil Moisture, Substrate Addition, and Incubation Time

    NASA Astrophysics Data System (ADS)

    Stark, J.

    2015-12-01

    Microbial carbon-use efficiency (CUE) is a key variable in biogeochemical cycling that regulates soil C sequestration, greenhouse gas emissions, and retention of inorganic nutrients. Microbial CUE is the fraction of C converted to biomass rather than respired as CO2. Biogeochemical models have been shown to be highly sensitive to variation in CUE; however, we currently have a poor understanding of how CUE responds to environmental variables such as soil moisture and nutrient limitations. We examined the effect of soil moisture and C supply on CUE in soil from a western hemlock / sitka spruce forest in Oregon, USA, using a novel technique which supplies 13C and 15N substrates through the gas phase so that water addition is not necessary. Soil samples (28 g oven-dry equiv. wt) at two water potentials (-0.03 and -3.55 MPa) were exposed to 13C-acetic acid vapor for either 6 or 30 sec to provide two different concentrations of acetate to soil microbial communities. The soils were also injected with small amounts of 15NH3 gas to allow quantification of microbial N assimilation rates and to provide an alternate method of calculating CUE. Rates of 13CO2 respiration were measured continuously during a 48-h incubation using cavity ring-down spectroscopy. Soil samples were extracted at seven time intervals (0, 0.5, 1.5, 4.5, 12, 24, and 48 h) in 0.5 M K2SO4 and analyzed for DO13C, microbial 13C, DO15N, inorganic 15N, and microbial 15N to calculate how gross rates of C and N assimilation and microbial CUE change with incubation time. As expected, microbial C and N assimilation rates and CUE increased with soil moisture and the quantity of acetate added; however, C:N assimilated was higher at lower soil moisture, suggesting that either C-storage compounds were being created, or that fungal communities were responsible for a greater proportion of the assimilation in drier soils. Assimilation rates and CUE also changed with incubation time, demonstrating that estimates of CUE

  15. Intermodal transfer of spent fuel

    SciTech Connect

    Neuhauser, K. S.; Weiner, R. F.

    1991-01-01

    As a result of the international standardization of containerized cargo handling in ports around the world, maritime shipment handling is particularly uniform. Thus, handier exposure parameters will be relatively constant for ship-truck and ship-rail transfers at ports throughout the world. Inspectors' doses are expected to vary because of jurisdictional considerations. The results of this study should be applicable to truck-to-rail transfers. A study of the movement of spent fuel casks through ports, including the loading and unloading of containers from cargo vessels, afforded an opportunity to estimate the radiation doses to those individuals handling the spent fuels with doses to the public along subsequent transportation routes of the fuel. A number of states require redundant inspections and for escorts over long distances on highways; thus handlers, inspectors, escort personnel, and others who are not normally classified as radiation workers may sustain doses high enough to warrant concern about occupational safety. This paper addresses the question of radiation safety for these workers. Data were obtained during, observation of the offloading of reactor spent fuel (research reactor spent fuel, in this instance) which included estimates of exposure times and distances for handlers, inspectors and other workers during offloading and overnight storage. Exposure times and distance were also for other workers, including crane operators, scale operators, security personnel and truck drivers. RADTRAN calculational models and parameter values then facilitated estimation of the dose to workers during incident-free ship-to-truck transfer of spent fuel.

  16. Team Work: Time well Spent

    ERIC Educational Resources Information Center

    Moore Johnson, Susan; Reinhorn, Stefanie K.; Simon, Nicole S.

    2016-01-01

    Teachers in high-poverty schools often feel stressed and fatigued. We might expect that if we ask these teachers to take on even more work by meeting regularly in collaborative improvement teams, they will respond with skepticism, even resentment. But in a study of 83 teachers in six outstanding high-poverty schools, these researchers found the…

  17. Oxidative dehydrogenation of ethane at millisecond contact times: Effect of H{sub 2} addition

    SciTech Connect

    Bodke, A.S.; Henning, D.; Schmidt, L.D.; Bharadwaj, S.S.; Maj, J.J.; Siddall, J.

    2000-04-01

    The oxidative dehydrogenation of ethane using Pt/{alpha}-Al{sub 2}O{sub 3} and various bimetallic catalysts operating at {approximately}1,000 C and very short contact times is examined with H{sub 2} addition to the feed. When H{sub 2} is added with a Pt catalyst, the ethylene selectivity rises from 65 to 72% but ethane conversion drops from 70 to 52%. However, using a Pt-Sn/{alpha}-Al{sub 2}O{sub 3} catalyst, the C{sub 2}H{sub 4} selectivity increases from 70 to greater than 85%, while the conversion remains {approximately}70%. The process also produces approximately as much H{sub 2} as is added to the feed. Effects of other metal promoters, sphere bed and fibermat supports, preheat, pressure, nitrogen dilution, and flow rate are examined in an effort to further elucidate the mechanism. Deactivation of the Pt-Sn catalyst is examined, and a simple method of regenerating the activity on-line is demonstrated. Possible mechanisms to explain high selectivities to ethylene are discussed. Although the process can be regarded as a simple two-step reaction sequence with the exothermic oxidation of hydrogen or ethane driving the endothermic dehydrogenation of ethane to ethylene, the exact contributions of heterogeneous or gas-phase reactions and their spatial variations within the catalyst are yet to be determined.

  18. Time- and Isomer-Resolved Measurements of Sequential Addition of Acetylene to the Propargyl Radical.

    PubMed

    Savee, John D; Selby, Talitha M; Welz, Oliver; Taatjes, Craig A; Osborn, David L

    2015-10-15

    Soot formation in combustion is a complex process in which polycyclic aromatic hydrocarbons (PAHs) are believed to play a critical role. Recent works concluded that three consecutive additions of acetylene (C2H2) to propargyl (C3H3) create a facile route to the PAH indene (C9H8). However, the isomeric forms of C5H5 and C7H7 intermediates in this reaction sequence are not known. We directly investigate these intermediates using time- and isomer-resolved experiments. Both the resonance stabilized vinylpropargyl (vp-C5H5) and 2,4-cyclopentadienyl (c-C5H5) radical isomers of C5H5 are produced, with substantially different intensities at 800 K vs 1000 K. In agreement with literature master equation calculations, we find that c-C5H5 + C2H2 produces only the tropyl isomer of C7H7 (tp-C7H7) below 1000 K, and that tp-C7H7 + C2H2 terminates the reaction sequence yielding C9H8 (indene) + H. This work demonstrates a pathway for PAH formation that does not proceed through benzene. PMID:26722791

  19. A Comparison of Variable Time-Compressed Speech and Normal Rate Speech Based on Time Spent and Performance in a Course Taught by Self-Instructional Methods

    ERIC Educational Resources Information Center

    Short, Sarah Harvey

    1977-01-01

    College students using variable rate controlled speech compressors as compared with normal speed tape recorders had an average time saving of 32 percent and an average grade increase of 4.2 points on post-test scores. (Author)

  20. Report on interim storage of spent nuclear fuel

    SciTech Connect

    Not Available

    1993-04-01

    The report on interim storage of spent nuclear fuel discusses the technical, regulatory, and economic aspects of spent-fuel storage at nuclear reactors. The report is intended to provide legislators state officials and citizens in the Midwest with information on spent-fuel inventories, current and projected additional storage requirements, licensing, storage technologies, and actions taken by various utilities in the Midwest to augment their capacity to store spent nuclear fuel on site.

  1. Lateralization of High-Frequency Clicks Based on Interaural Time: Additivity of Information across Frequency

    NASA Astrophysics Data System (ADS)

    Wenzel, Elizabeth Marie

    Lateralization performance based on interaural differences of time (IDTs) was measured for trains of Gaussian clicks which varied in spectral content. In the first experiment, thresholds ((DELTA)IDTs) were measured as a function of the number of clicks in the train (n = 1 to 32), the interclick interval (ICI = 2.5 or 5 ms), and the spectral content (1 vs. 2 or 4 carriers). Subjects' performance was compared to perfect statistical summation which predicts slopes of -.50 when log-(DELTA)IDT vs. long -n is plotted. The results showed that increasing the spectral content of the clicks decreased the intercepts of the log -log functions (decreased thresholds) while having little effect on their slopes. Shortening the ICIs caused the slopes of the functions to decrease in absolute value. To estimate the bandwidth of frequency-interaction in lateralization, d's were measured for clicks with constant IDTs (n = 1) with a fixed carrier (FF = 4000, 5200, 6000 or 7200 Hz), both alone and combined with a second click whose carrier (F) varied from 3500 to 8500 Hz. Performance in combined conditions was compared to independent summation of the information carried by the two frequency-bands. Performance improved as the separation between F and FF increased until the level predicted by independence was reached. The final experiment investigated the interaction of frequency content with IDT. d's were measured as a function of the IDT in clicks with carriers of 5200, 6000 or 7200 Hz, both alone and combined with a 4000-Hz click with a fixed IDT. Performance in combined conditions was again compared to independent additivity. The improvement with frequency was explained by an increase in the number of samples of the IDT reaching the binaural centers due to spread of excitation along the basilar membrane. Less than independent summation was explained by correlation between overlapping bands which reduced the amount of information exciting independent channels. The data also suggest that

  2. Suitability of live yeast addition to alleviate the adverse effects due to the restriction of the time of access to feed in sheep fed only pasture.

    PubMed

    Pérez-Ruchel, A; Repetto, J L; Cajarville, C

    2013-12-01

    The effect of yeast addition on intake and digestive utilization of pasture was studied in ovines under restricted time of access to forage. Eighteen wethers housed in metabolic cages and fed fresh forage (predominantly Lotus corniculatus) were randomly assigned to three treatments: forage available all day (AD); forage available only 6 h/day (R) and forage available only 6 h/day plus live Saccharomyces cerevisiae yeast (RY). Feed intake and digestibility, feeding behaviour, kinetics of passage, ruminal pH and ammonia concentration, nitrogen balance and microbial nitrogen synthesis (MNS) were determined in vivo, and ruminal liquor activity of animals was evaluated in vitro. Restricted animals consumed less than those fed all day but achieved more than 75% of the intake and spent less time ruminating (p = 0.014). Although animals without restriction consumed more feed, they had a lower rate of passage (p = 0.030). The addition of yeast did affect neither intake nor feeding behaviour, but increased digestibility. Organic matter digestibility tended to increase 11% by yeast addition (p = 0.051), mainly by a rise in NDF (27%, p = 0.032) and ADF digestibility (37%, p = 0.051). Ingested and retained N was lower in restricted animals, as MNS (p ≤ 0.045). The use of yeasts did not significantly change the N balance or MNS, but retained N tended to be higher in supplemented animals (p = 0.090). Neither ruminal pH nor ammonia concentrations were affected by the restriction, but restricted animals had a lower ruminal activity evidenced by a lower volume of gas (p = 0.020). The addition of yeast overcame this limitation, noted by a higher volume of gas of inocula from supplemented animals (p = 0.015). Yeast addition emerged as a useful tool to improve digestibility of forage cell walls in ovines under restricted time of access to forage. PMID:23020124

  3. Recovery and recycle of valuable constituents in spent pickling acids

    SciTech Connect

    Thornburg, G. ); McArdle, J.C.; Piccari, J.A.; Byszewski, C.H. )

    1990-11-01

    An acid recovery system has been successfully operated for over two years at Washington Steel Corporation, Washington, Pennsylvania. During this time the system has effectively recycled the valuable components in spent pickling acids, thereby significantly reducing the costs and liabilities associated with the disposal of these hazardous wastes. Integration of the system into existing pickle line operations has the additional benefit of improving the quality and consistency of the pickled steel product, as well as reducing maintenance on the tubs.

  4. Effects of Wait Time When Communicating with Children Who Have Sensory and Additional Disabilities

    ERIC Educational Resources Information Center

    Johnson, Nicole; Parker, Amy T.

    2013-01-01

    Introduction: This study utilized wait-time procedures to determine if they are effective in helping children with deafblindness or multiple disabilities that include a visual impairment communicate in their home. Methods: A single subject with an alternating treatment design was used for the study. Zero- to one-second wait time was utilized…

  5. Addition of random run FM noise to the KPW time scale algorithm

    NASA Technical Reports Server (NTRS)

    Greenhall, C. A.

    2002-01-01

    The KPW (Kalman plus weights) time scale algorithm uses a Kalman filter to provide frequency and drift information to a basic time scale equation. This paper extends the algorithm to three-state clocks nd gives results for a simulated eight-clock ensemble.

  6. High-Challenge Teaching for Senior English as an Additional Language Learners in Times of Change

    ERIC Educational Resources Information Center

    Alford, Jennifer; Jetnikoff, Anita

    2011-01-01

    This paper will present a brief overview of the recent shifts within English and EAL/D (English as an additional language/dialect) curriculum documents and their focus on critical literacy, using the Queensland context as a case in point. The English syllabus landscape in Queensland has continued to morph in recent years. From 2002 to 2009,…

  7. Effect of Hydrogen Addition on Methane HCCI Engine Ignition Timing and Emissions Using a Multi-zone Model

    NASA Astrophysics Data System (ADS)

    Wang, Zi-han; Wang, Chun-mei; Tang, Hua-xin; Zuo, Cheng-ji; Xu, Hong-ming

    2009-06-01

    Ignition timing control is of great importance in homogeneous charge compression ignition engines. The effect of hydrogen addition on methane combustion was investigated using a CHEMKIN multi-zone model. Results show that hydrogen addition advances ignition timing and enhances peak pressure and temperature. A brief analysis of chemical kinetics of methane blending hydrogen is also performed in order to investigate the scope of its application, and the analysis suggests that OH radical plays an important role in the oxidation. Hydrogen addition increases NOx while decreasing HC and CO emissions. Exhaust gas recirculation (EGR) also advances ignition timing; however, its effects on emissions are generally the opposite. By adjusting the hydrogen addition and EGR rate, the ignition timing can be regulated with a low emission level. Investigation into zones suggests that NOx is mostly formed in core zones while HC and CO mostly originate in the crevice and the quench layer.

  8. Spent-fuel storage requirements

    NASA Astrophysics Data System (ADS)

    1982-06-01

    Spent fuel storage requirements, as projected through the year 2000 for U.S. LWRs, were calculated using information supplied by the utilities reflecting plant status as of December 31, 1981. Projections through the year 2000 combined fuel discharge projections of the utilities with the assumed discharges of typical reactors required to meet the nuclear capacity of 165 GWe projected by the Energy Information Administration for the year 2000. Three cases were developed and are summarized. A reference case, or maximum at-reactor capacity case, assumes that all reactor storage pools are increased to their maximum capacities as estimated by the utilities for spent fuel storage utilizing currently licensed technologies. The reference case assumes no transshipments between pools except as current licensed by the Nuclear Regulatory Commission. This case identifies an initial requirement for 13 MTU of additional storage in 1984, and a cumulative requirement for 14,490 MTU additional storage in the year 2000.

  9. Methodology for determining criteria for storing spent fuel in air

    SciTech Connect

    Reid, C.R.; Gilbert, E.R.

    1986-11-01

    Dry storage in an air atmosphere is a method being considered for spent light water reactor (LWR) fuel as an alternative to storage in an inert gas environment. However, methods to predict fuel integrity based on oxidation behavior of the fuel first must be evaluated. The linear cumulative damage method has been proposed as a technique for defining storage criteria. Analysis of limited nonconstant temperature data on nonirradiated fuel samples indicates that this approach yields conservative results for a strictly decreasing-temperature history. On the other hand, the description of damage accumulation in terms of remaining life concepts provides a more general framework for making predictions of failure. Accordingly, a methodology for adapting remaining life concepts to UO/sub 2/ oxidation has been developed at Pacific Northwest Laboratory. Both the linear cumulative damage and the remaining life methods were used to predict oxidation results for spent fuel in which the temperature was decreased with time to simulate the temperature history in a dry storage cask. The numerical input to the methods was based on oxidation data generated with nonirradiated UO/sub 2/ pellets. The calculated maximum allowable storage temperatures are strongly dependent on the temperature-time profile and emphasize the conservatism inherent in the linear cumulative damage model. Additional nonconstant temperature data for spent fuel are needed to both validate the proposed methods and to predict temperatures applicable to actual spent fuel storage.

  10. Equivalence of time and aperture domain additive noise in ultrasound coherence

    PubMed Central

    Bottenus, Nick B.; Trahey, Gregg E.

    2015-01-01

    Ultrasonic echoes backscattered from diffuse media, recorded by an array transducer and appropriately focused, demonstrate coherence predicted by the van Cittert–Zernike theorem. Additive noise signals from off-axis scattering, reverberation, phase aberration, and electronic (thermal) noise can all superimpose incoherent or partially coherent signals onto the recorded echoes, altering the measured coherence. An expression is derived to describe the effect of uncorrelated random channel noise in terms of the noise-to-signal ratio. Equivalent descriptions are made in the aperture dimension to describe uncorrelated magnitude and phase apodizations of the array. Binary apodization is specifically described as an example of magnitude apodization and adjustments are presented to minimize the artifacts caused by finite signal length. The effects of additive noise are explored in short-lag spatial coherence imaging, an image formation technique that integrates the calculated coherence curve of acquired signals up to a small fraction of the array length for each lateral and axial location. A derivation of the expected contrast as a function of noise-to-signal ratio is provided and validation is performed in simulation. PMID:25618045

  11. HYDRAULIC CEMENT PREPARATION FROM LURGI SPENT SHALE

    SciTech Connect

    Mehta, P.K.; Persoff, P.; Fox, J.P.

    1980-06-01

    Low cost material is needed for grouting abandoned retorts. Experimental work has shown that a hydraulic cement can be produced from Lurgi spent shale by mixing it in a 1:1 weight ratio with limestone and heating one hour at 1000°C. With 5% added gypsum, strengths up to 25.8 MPa are obtained. This cement could make an economical addition up to about 10% to spent shale grout mixes, or be used in ordinary cement applications.

  12. Investigating critical effects of variegated lubricants, glidants and hydrophilic additives on lag time of press coated ethylcellulose tablets.

    PubMed

    Patadia, Riddhish; Vora, Chintan; Mittal, Karan; Mashru, Rajashree

    2016-01-01

    The research envisaged focuses on vital impacts of variegated lubricants, glidants and hydrophilic additives on lag time of press coated ethylcellulose (EC) tablets using prednisone as a model drug. Several lubricants and glidants such as magnesium stearate, colloidal SiO2, sodium stearyl fumarate, talc, stearic acid, polyethylene glycol (6000) and glyceryl behenate were investigated to understand their effects on lag time by changing their concentrations in outer coat. Further, the effects of hydrophilic additives on lag time were examined for hydroxypropylmethylcellulose (E5), hydroxypropylcellulose (EF and SSL), povidone (K30), copovidone, polyethylene glycol (4000), lactose and mannitol. In vitro drug release testing revealed that each selected lubricant/glidant, if present even at concentration of 0.25% w/w, significantly reduced the lag time of press coated tablets. Specifically, colloidal SiO2 and/or magnesium stearate were detrimental while other lubricants/glidants were relatively less injurious. Among hydrophilic additives, freely water soluble fillers had utmost influence in lag time, whereas, comparatively less impact was observed with polymeric binders. Concisely, glidant and lubricant should be chosen to have minimal impact on lag time and further judicious selection of hydrophilic additives should be exercised for modulating lag time of pulsatile release formulations. PMID:25566928

  13. Vectran Fiber Time-Dependent Behavior and Additional Static Loading Properties

    NASA Technical Reports Server (NTRS)

    Fette, Russell B.; Sovinski, Marjorie F.

    2004-01-01

    Vectran HS appears from literature and testing to date to be an ideal upgrade from Kevlar braided cords for many long-term, static-loading applications such as tie-downs on solar arrays. Vectran is a liquid crystalline polymer and exhibits excellent tensile properties. The material has been touted as a zero creep product. Testing discussed in this report does not support this statement, though the creep is on the order of four times slower than with similar Kevlar 49 products. Previous work with Kevlar and new analysis of Vectran testing has led to a simple predictive model for Vectran at ambient conditions. The mean coefficient of thermal expansion (negative in this case) is similar to Kevlar 49, but is not linear. A positive transition in the curve occurs near 100 C. Out-gassing tests show that the material performs well within parameters for most space flight applications. Vectran also offers increased abrasion resistance, minimal moisture regain, and similar UV degradation. The effects of material construction appear to have a dramatic effect in stress relaxation for braided Vectran. To achieve the improved relaxation rate, upgrades must also examine alternate construction or preconditioning methods. This report recommends Vectran HS as a greatly improved replacement material for applications where time-dependent relaxation is a major factor.

  14. Effect of Powder Reuse Times on Additive Manufacturing of Ti-6Al-4V by Selective Electron Beam Melting

    NASA Astrophysics Data System (ADS)

    Tang, H. P.; Qian, M.; Liu, N.; Zhang, X. Z.; Yang, G. Y.; Wang, J.

    2015-03-01

    An advantage of the powder-bed-based metal additive manufacturing (AM) processes is that the powder can be reused. The powder reuse or recycling times directly affect the affordability of the additively manufactured parts, especially for the AM of titanium parts. This study examines the influence of powder reuse times on the characteristics of Ti-6Al-4V powder, including powder composition, particle size distribution (PSD), apparent density, tap density, flowability, and particle morphology. In addition, tensile samples were manufactured and evaluated with respect to powder reuse times and sample locations in the powder bed. The following findings were made from reusing the same batch of powder 21 times for AM by selective electron beam melting: (i) the oxygen (O) content increased progressively with increasing reuse times but both the Al content and the V content remained generally stable (a small decrease only); (ii) the powder became less spherical with increasing reuse times and some particles showed noticeable distortion and rough surfaces after being reused 16 times; (iii) the PSD became narrower and few satellite particles were observed after 11 times of reuse; (iv) reused powder showed improved flowability; and (v) reused powder showed no measurable undesired influence on the AM process and the samples exhibited highly consistent tensile properties, irrespective of their locations in the powder bed. The implications of these findings were discussed.

  15. Evaluation of Dechlorinating Chemicals for Spent Membrane Cleaning Solutions.

    PubMed

    Ko, Jiyun; Parker, Wayne; Liu, Jun

    2016-04-01

    The use of dechlorinating chemicals for removal of chlorine from spent membrane cleaning solutions was investigated. Addition of calcium thiosulfate resulted in a decrease in pH at low dosages of calcium thiosulfate, but when higher dosages were used, the pH was not affected. Other dechlorinating agents (sodium bisulfite, sodium sulfite, and ascorbic acid) generated smaller pH declines than calcium thiosulfate. The declines in pH were observed after the dechlorination reaction was effectively complete and pH did not appear to influence the rate of dechlorination. The rate of dechlorination in spent cleaning solution was slower than that observed in clean water. Dechlorination with calcium thiosulfate resulted in the lowest half-life and reaction time. At lower doses (less than 565 mg/L), it was not possible to discriminate between the different dechlorinating agents. The times required for dechlorination were more sensitive to increases in dechlorination chemical dose at lower doses. PMID:27131060

  16. Near-term commercial spent fuel shipping cask requirements

    SciTech Connect

    Daling, P.M.

    1984-11-01

    This report describes an analysis of the near-term commercial light water reactor (LWR) spent fuel transportation system. The objective was to determine if the existing commercial spent fuel shipping cask fleet is adequate to provide the needed transportation services for the period of time the US government would be authorized to accept spent fuel for Federal Interim Storage (FIS). A spent fuel shipping cask supply-demand analysis was performed to evaluate the existing fleet size. The results of the shipping cask handling capability study indicated that by weight, 75% of the spent fuel shipments will be by truck (overweight plus legal-weight truck). From the results of the shipping cask supply-demand analysis it was concluded that, if utilities begin large-scale applications for FIS, the five legal-weight truck (LWT) casks currently in service would be inadequate to perform all of the needed shipments as early as 1987. This further assumes that a western site would be selected for the FIS facility. If the FIS site were to be located in the East, the need for additional LWT casks would be delayed by about two years. The overweight truck (OWT) cask fleet (two PWR and two BWR versions) will be adequate through 1992 if some shipments to FIS can be made several years before a reactor is projected to lose full core reserve. This is because OWT cask requirements increase gradually over the next several years. The feasibility of shipping before losing full core reserve has not been evaluated. Cask utilization requirements in later years will be reduced if some shipments can be made prior to the time they are actually needed. The existing three rail casks are adequate to perform near-term shipments. 18 references, 4 figures, 18 tables.

  17. 26 CFR 301.6110-5 - Notice and time requirements; actions to restrain disclosure; actions to obtain additional...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the Internal Revenue Service determines that the request constitutes a request for disclosure of the... the Internal Revenue Service has determined that additional disclosure of information other than the... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Notice and time requirements; actions...

  18. Effect of enzyme concentration, addition of water and incubation time on increase in yield of starch from potato.

    PubMed

    Sit, Nandan; Agrawal, U S; Deka, Sankar C

    2014-05-01

    Enzymatic treatment process for starch extraction from potato was investigated using cellulase enzyme and compared with conventional process. The effects of three parameters, cellulase enzyme concentration, incubation time and addition of water were evaluated for increase in starch yield as compared to the conventional process i.e., without using enzyme. A two-level full factorial design was used to study the process. The results indicated that all the main parameters and their interactions are statistically significant. Enzyme concentration and incubation time had a positive effect on the increase in starch yield while addition of water had a negative effect. The increase in starch yield ranged from 1.9% at low enzyme concentration and incubation time and high addition of water to a maximum of 70% increase from conventional process in starch yield was achieved when enzyme concentration and incubation time were high and addition of water was low suggesting water present in the ground potato meal is sufficient for access to the enzyme with in the slurry ensuring adequate contact with the substrate. PMID:24803713

  19. 38 CFR 20.304 - Rule 304. Filing additional evidence does not extend time limit for appeal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Rule 304. Filing additional evidence does not extend time limit for appeal. 20.304 Section 20.304 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) BOARD OF VETERANS' APPEALS: RULES OF PRACTICE Filing § 20.304 Rule 304. Filing...

  20. Processing time of addition or withdrawal of single or combined balance-stabilizing haptic and visual information.

    PubMed

    Honeine, Jean-Louis; Crisafulli, Oscar; Sozzi, Stefania; Schieppati, Marco

    2015-12-01

    We investigated the integration time of haptic and visual input and their interaction during stance stabilization. Eleven subjects performed four tandem-stance conditions (60 trials each). Vision, touch, and both vision and touch were added and withdrawn. Furthermore, vision was replaced with touch and vice versa. Body sway, tibialis anterior, and peroneus longus activity were measured. Following addition or withdrawal of vision or touch, an integration time period elapsed before the earliest changes in sway were observed. Thereafter, sway varied exponentially to a new steady-state while reweighting occurred. Latencies of sway changes on sensory addition ranged from 0.6 to 1.5 s across subjects, consistently longer for touch than vision, and were regularly preceded by changes in muscle activity. Addition of vision and touch simultaneously shortened the latencies with respect to vision or touch separately, suggesting cooperation between sensory modalities. Latencies following withdrawal of vision or touch or both simultaneously were shorter than following addition. When vision was replaced with touch or vice versa, adding one modality did not interfere with the effect of withdrawal of the other, suggesting that integration of withdrawal and addition were performed in parallel. The time course of the reweighting process to reach the new steady-state was also shorter on withdrawal than addition. The effects of different sensory inputs on posture stabilization illustrate the operation of a time-consuming, possibly supraspinal process that integrates and fuses modalities for accurate balance control. This study also shows the facilitatory interaction of visual and haptic inputs in integration and reweighting of stance-stabilizing inputs. PMID:26334013

  1. Novel approach to recover cobalt and lithium from spent lithium-ion battery using oxalic acid.

    PubMed

    Zeng, Xianlai; Li, Jinhui; Shen, Bingyu

    2015-09-15

    With the booming of consumer electronics (CE) and electric vehicle (EV), a large number of spent lithium-ion battery (LIBs) have been generated worldwide. Resource depletion and environmental concern driven from the sustainable industry of CE and EV have motivated spent LIBs should be recovered urgently. However, the conventional process combined with leaching, precipitating, and filtering was quite complicated to recover cobalt and lithium from spent LIBs. In this work, we developed a novel recovery process, only combined with oxalic acid leaching and filtering. When the optimal parameters for leaching process is controlled at 150 min retention time, 95 °C heating temperature, 15 g L(-1) solid-liquid ratio, and 400 rpm rotation rate, the recovery rate of lithium and cobalt from spent LIBs can reach about 98% and 97%, respectively. Additionally, we also tentatively discovered the leaching mechanism of lithium cobalt oxide (LiCoO2) using oxalic acid, and the leaching order of the sampling LiCoO2 of spent LIBs. All the obtained results can contribute to a short-cut and high-efficiency process of spent LIBs recycling toward a sound closed-loop cycle. PMID:25897692

  2. Spent fuel receipt scenarios study

    SciTech Connect

    Ballou, L.B.; Montan, D.N.; Revelli, M.A.

    1990-09-01

    This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs.

  3. Effect of ultrasound treatment, oil addition and storage time on lycopene stability and in vitro bioaccessibility of tomato pulp.

    PubMed

    Anese, Monica; Bot, Francesca; Panozzo, Agnese; Mirolo, Giorgio; Lippe, Giovanna

    2015-04-01

    This study was performed to investigate the influence of ultrasound processing on tomato pulp containing no sunflower oil, or increasing amounts (i.e. 2.5%, 5% and 10%), on lycopene concentration and in vitro bioaccessibility at time zero and during storage at 5 °C. Results confirmed previous findings in that ultrasonication was responsible for cell breakage and subsequent lycopene release in a highly viscous matrix. Neither the ultrasound process nor oil addition affected lycopene concentration. A decrease of approximately 35% lycopene content occurred at storage times longer than 15 days, due to isomerisation and oxidation reactions. No differences in lycopene in vitro bioaccessibility were found between the untreated and ultrasonically treated samples; this parameter decreased as a consequence of oil addition. Losses of lycopene in vitro bioaccessibility ranging between 50% and 80% occurred in the untreated and ultrasonically treated tomato pulps with and without oil during storage, mainly due to carotenoid degradation. PMID:25442608

  4. Optimizing the performance of a reactor by reducing the retention time and addition of glycerin for anaerobically digesting manure

    PubMed Central

    Timmerman, Maikel; Schuman, Els; van Eekert, Miriam; van Riel, Johan

    2015-01-01

    Anaerobic digestion of manure is a widely accepted technology for energy production. However, only a minimal portion of the manure production in the EU is anaerobically digested and occurs predominantly in codigestion plants. There is substantial potential for biogas plants that primarily operate on manure (>90%); however, the methane yields of manure are less compared to coproducts, which is one of the reasons for manure-based biogas plants often being economically non-viable. Therefore, it is essential to begin increasing the efficiency of these biogas plants. This study investigated the effect of decreasing retention time and introducing a moderate amount of glycerin on the biogas production as methods to improve efficiency. An experiment has been conducted with two different manure types in four biogas reactors. The results of the study demonstrated that, first, it was possible to decrease the retention time to 10–15 days; however, the effect on biogas production varied per manure type. Secondly, the biogas production almost triples at a retention time of 15.6 days with an addition of 4% glycerin. The relative production-enhancing effect of glycerin did not vary significantly with both manure types. However, the absolute production-enhancing effect of glycerin differed per manure type since the biogas production per gram VS differed per manure type. Thirdly, the positive effect of the glycerin input declines with shorter retention times. Therefore, the effect of glycerin addition depends on the manure type and retention time. PMID:25401272

  5. Spent brewer's yeast extract as an ingredient in cooked hams.

    PubMed

    Pancrazio, Gaston; Cunha, Sara C; de Pinho, Paula Guedes; Loureiro, Mónica; Meireles, Sónia; Ferreira, Isabel M P L V O; Pinho, Olívia

    2016-11-01

    This work describes the effect of the incorporation of 1% spent yeast extract into cooked hams. Physical/chemical/sensorial characteristics and changes during 12 and 90days storage were evaluated on control and treated cooked hams processed for 1.5, 2.0, 2.5 or 3h. Spent yeast extract addition increased hardness, chewiness, ash, protein and free amino acid content. Similar volatile profiles were obtained, although there were some quantitative differences. No advantages were observed for increased cooking time. No significant differences were observed for physical and sensorial parameters of cooked hams with spent yeast extract at 12 and 90days post production, but His, aldehydes and esters increased at the end of storage. This behaviour was similar to that observed for control hams. The higher hardness of cooked ham with 1% yeast extract was due to the stronger gel formed during cooking and was maintained during storage. This additive acts as gel stabilizer for cooked ham production and could potentially improve other processing characteristics. PMID:27449232

  6. Predicting fissile content of spent nuclear fuel assemblies with the passive neutron Albedo reactivity technique and Monte Carlo code emulation

    SciTech Connect

    Conlin, Jeremy Lloyd; Tobin, Stephen J

    2010-10-13

    There is a great need in the safeguards community to be able to nondestructively quantify the mass of plutonium of a spent nuclear fuel assembly. As part of the Next Generation of Safeguards Initiative, we are investigating several techniques, or detector systems, which, when integrated, will be capable of quantifying the plutonium mass of a spent fuel assembly without dismantling the assembly. This paper reports on the simulation of one of these techniques, the Passive Neutron Albedo Reactivity with Fission Chambers (PNAR-FC) system. The response of this system over a wide range of spent fuel assemblies with different burnup, initial enrichment, and cooling time characteristics is shown. A Monte Carlo method of using these modeled results to estimate the fissile content of a spent fuel assembly has been developed. A few numerical simulations of using this method are shown. Finally, additional developments still needed and being worked on are discussed.

  7. Effect of cycle time on fungal morphology, broth rheology, and recombinant enzyme productivity during pulsed addition of limiting carbon source.

    PubMed

    Bhargava, Swapnil; Wenger, Kevin S; Rane, Kishore; Rising, Vanessa; Marten, Mark R

    2005-03-01

    For many years, high broth viscosity has remained a key challenge in large-scale filamentous fungal fermentations. In previous studies, we showed that broth viscosity could be reduced by pulsed addition of limiting carbon during fed-batch fermentation. The objective in this study was to determine how changing the frequency of pulsed substrate addition affects fungal morphology, broth rheology, and recombinant enzyme productivity. To accomplish this, a series of duplicate fed-batch fermentations were performed in 20-L fermentors with a recombinant glucoamylase producing strain of Aspergillus oryzae. The total cycle time for substrate pulsing was varied over a wide range (30-2,700 s), with substrate added only during the first 30% of each cycle. As a control, a fermentation was conducted with continuous substrate feeding, and in all fermentations the same total amount of substrate was added. Results show that the total biomass concentration remained relatively unaltered, while a substantial decrease in the mean projected area of fungal elements (i.e., average size) was observed with increasing cycle time. This led to reduced broth viscosity and increased oxygen uptake rate. However, high values of cycle time (i.e., 900-2,700 s) showed a significant increase in fungal conidia formation and significantly reduced recombinant enzyme productivity, suggesting that the fungi channeled substrate to storage compounds rather than to recombinant protein. In addition to explaining the effect of cycle time on fermentation performance, these results may aid in explaining the discrepancies observed on scale-up to larger fermentors. PMID:15643626

  8. Spent fuel shortage: Facts booklet

    NASA Astrophysics Data System (ADS)

    1980-04-01

    In October 1977, the Department of Energy (DOE) announced a spent nuclear fuel policy where the Government would, under certain conditions, take title of and store spent nuclear fuel from commercial power reactors. The policy is intended to provide spent fuel storage until final disposition is available. The DOE has programs for providing safe, long-term disposal of nuclear waste. The spent fuel storage program is one element of waste management and compliments the disposal program. The costs for spent fuel services are to be fully recovered by the Government from the utilities. This will allow the utilities to confidently consider the costs for disposition of spent fuel in their rate structure. The United States would also store limited amounts of foreign spent fuel to meet nonproliferation objectives. This booklet summarizes information on many aspects of spent fuel storage.

  9. Spent fuel storage. Facts booklet

    SciTech Connect

    1980-04-01

    In October 1977, the Department of Energy (DOE) announced a spent nuclear fuel policy where the Government would, under certain conditions, take title to and store spent nuclear fuel from commercial power reactors. The policy is intended to provide spent fuel storage until final disposition is available. DOE has programs for providing safe, long-term disposal of nuclear waste. The spent fuel storage program is one element of waste management and compliments the disposal program. The costs for spent fuel services are to be fully recovered by the Government from the utilities. This will allow the utilities to confidently consider the costs for disposition of spent fuel in their rate structure. The United States would also store limited amounts of foreign spent fuel to meet nonproliferation objectives. This booklet summarizes information on many aspects of spent fuel storage.

  10. Simulation of differential die-away instrument’s response to asymmetrically burned spent nuclear fuel

    SciTech Connect

    Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; Svard, Staffan Jacobsson; Jansson, Peter; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-03-04

    Here, previous simulation studies of Differential Die–Away (DDA) instrument’s response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument’s response to interrogation of asymmetrically burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs.

  11. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  12. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  13. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  14. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  15. The effect of exercise training with an additional inspiratory load on inspiratory muscle fatigue and time-trial performance.

    PubMed

    McEntire, Serina J; Smith, Joshua R; Ferguson, Christine S; Brown, Kelly R; Kurti, Stephanie P; Harms, Craig A

    2016-08-01

    The purpose was to determine the effect of moderate-intensity exercise training (ET) on inspiratory muscle fatigue (IMF) and if an additional inspiratory load during ET (ET+IL) would further improve inspiratory muscle strength, IMF, and time-trial performance. 15 subjects were randomly divided to ET (n=8) and ET+IL groups (n=7). All subjects completed six weeks of exercise training three days/week at ∼70%V̇O2peak for 30min. The ET+IL group breathed through an inspiratory muscle trainer (15% PImax) during exercise. 5-mile, and 30-min time-trials were performed pre-training, weeks three and six. Inspiratory muscle strength increased (p<0.05) for both groups to a similar (p>0.05) extent. ET and ET+IL groups improved (p<0.05) 5-mile time-trial performance (∼10% and ∼18%) and the ET+IL group was significantly faster than ET at week 6. ET and ET+IL groups experienced less (p<0.05) IMF compared to pre-training following the 5-mile time-trial. In conclusion, these data suggest ET leads to less IMF, ET+IL improves inspiratory muscle strength and IMF, but not different than ET alone. PMID:27195511

  16. Understanding Solidification of Polythiophene Thin Films during Spin-Coating: Effects of Spin-Coating Time and Processing Additives

    PubMed Central

    Na, Jin Yeong; Kang, Boseok; Sin, Dong Hun; Cho, Kilwon; Park, Yeong Don

    2015-01-01

    Spin-coating has been used extensively in the fabrication of electronic devices; however, the effects of the processing parameters have not been fully explored. Here, we systematically characterize the effects of the spin-coating time on the microstructure evolution during semiconducting polymer solidification in an effort to establish the relationship between this parameter and the performances of the resulting polymer field-effect transistors (FETs). We found that a short spin-coating time of a few seconds dramatically improve the morphology and molecular order in a conjugated polymer thin film because the π-π stacking structures formed by the polymer molecules grow slowly and with a greater degree of order due to the residual solvent present in the wet film. The improved ordering is correlated with improved charge carrier transport in the FETs prepared from these films. We also demonstrated the effects of various processing additives on the resulting FET characteristics as well as on the film drying behavior during spin-coating. The physical properties of the additives are found to affect the film drying process and the resulting device performance. PMID:26299676

  17. Thermoelectric powered wireless sensors for spent fuel monitoring

    SciTech Connect

    Carstens, T.; Corradini, M.; Blanchard, J.; Ma, Z.

    2011-07-01

    This paper describes using thermoelectric generators to power wireless sensors to monitor spent nuclear fuel during dry-cask storage. OrigenArp was used to determine the decay heat of the spent fuel at different times during the service life of the dry-cask. The Engineering Equation Solver computer program modeled the temperatures inside the spent fuel storage facility during its service life. The temperature distribution in a thermoelectric generator and heat sink was calculated using the computer program Finite Element Heat Transfer. From these temperature distributions the power produced by the thermoelectric generator was determined as a function of the service life of the dry-cask. In addition, an estimation of the path loss experienced by the wireless signal can be made based on materials and thickness of the structure. Once the path loss is known, the transmission power and thermoelectric generator power requirements can be determined. This analysis estimates that a thermoelectric generator can produce enough power for a sensor to function and transmit data from inside the dry-cask throughout its service life. (authors)

  18. Thermal Hydraulic Analysis of Spent Fuel Casks

    SciTech Connect

    Rector, D. R.; Cuta, J. M.; Enderlin, C. W.

    1997-10-08

    COBRA-SFS (Spent Fuel Storage) is a code for thermal-hydraulic analysis of multi-assembly spent fuel storage and transportation systems. It uses a lumped parameter finite difference approach to predict flow and temperature distributions in spent fuel storage systems and fuel assemblies, under forced and natural convection heat transfer conditions. Derived from the COBRA family of codes, which have been extensively evaluated against in-pile and out-of-pile data, COBRA-SFS retains all the important features of the COBRA codes for single phase fluid analysis, and extends the range application to include problems with two-dimensional radiative and three-dimensional conductive heat transfer. COBRA-SFS has been used to analyze various single- and multi-assembly spent fuel storage systems containing unconsolidated and consolidated fuel rods, with a variety of fill media, including air, helium and vacuum. Cycle 0 of COBRA-SFS was released in 1986. Subsequent applications of the code led to development of additional capabilities, which resulted in the release of Cycle 1 in February 1989. Since then, the code has undergone an independent technical review as part of a submittal to the Nuclear Regulatory Commission for a generic license to apply the code to spent fuel storage system analysis. Modifications and improvements to the code have been combined to form Cycle 2. Cycle 3., the newest version of COBRA-SFS, has been validated and verified for transient applications, such as a storage cask thermal response to a pool fire.

  19. Determination of Plutonium Content in Spent Fuel with Nondestructive Assay

    SciTech Connect

    Tobin, S. J.; Sandoval, N. P.; Fensin, M. L.; Lee, S. Y.; Ludewigt, Bernhard A.; Menlovea, H. O.; Quiter, B. J.; Rajasingume, A.; Schearf, M. A.; Smith, L. E.; Swinhoe, M. T.; Thompson, S. J.

    2009-06-30

    There are a variety of reasons for quantifying plutonium (Pu) in spent fuel such as independently verifying the Pu content declared by a regulated facility, making shipper/receiver mass declarations, and quantifying the input mass at a reprocessing facility. As part of the Next Generation Safeguards Initiative, NA-241 has recently funded a multilab/university collaboration to determine the elemental Pu mass in spent fuel assemblies. This research effort is anticipated to be a five year effort: the first part of which is a two years Monte Carlo modeling effort to integrate and down-select among 13 nondestructive assay (NDA) technologies, followed by one year for fabricating instruments and then two years for measuring spent fuel. This paper gives a brief overview of the approach being taken for the Monte Carlo research effort. In addition, preliminary results for the first NDA instrument studied in detail, delayed neutron detection, will be presented. In order to cost effectively and robustly model the performance of several NDA techniques, an"assembly library" was created that contains a diverse range of pressurized water reactor spent fuel assemblies (burnup, enrichment, cooling time) similar to that which exists in spent pools today and in the future, diversion scenarios that capture a range of possible rod removal options, spatial and isotopic detail needed to accurately quantify the capability of all the NDA techniques so as to enable integration. Integration is being designed into this study from the beginning since it is expected that the best performance will be obtained by combining a few NDA techniques. The performance of each instrument will be quantified for the full assembly library in three different media: air, water and borated water. In this paper the preliminary capability of delayed neutron detection will be quantified for the spent fuel library for all three media. The 13 NDA techniques being researched are the following: Delayed Gamma, Delayed

  20. Performing forward-viewing endoscopy at time of pancreaticobiliary EUS and ERCP may detect additional upper gastrointestinal lesions

    PubMed Central

    Thomas, Ashby; Vamadevan, Arunan S; Slattery, Eoin; Sejpal, Divyesh V; Trindade, Arvind J

    2016-01-01

    Background and study aims: It is unknown whether significant incidental upper gastrointestinal lesions are missed when using non-forward-viewing endoscopes without completing a forward-viewing exam in linear endoscopic ultrasound (EUS) or endoscopic retrograde cholangiopancreatography (ERCP) exams. We evaluated whether significant upper GI lesions are missed during EUS and ERCP when upper endoscopy is not performed routinely with a gastroscope. Patients and methods: A retrospective analysis was performed in which an EGD with a forward-viewing gastroscope was performed after using a non-forward-viewing endoscope (linear echoendoscope, duodenoscope, or both) during a single procedure. Upper gastrointestinal tract findings were recorded separately for each procedure. Significant lesions found with a forward-viewing gastroscope were defined as findings that led to a change in the patient’s medication regimen, additional endoscopic surveillance/interventions, or the need for other imaging studies. Results: A total of 168 patients were evaluated. In 83 patients, a linear echoendoscope was used, in 52 patients a duodenoscope was used, and in 33 patients both devices were used. Clinically significant additional lesions diagnosed with a gastroscope but missed by a non-forward-viewing endoscope were found in 30 /168 patients (18 %). EGD after linear EUS resulted in additional lesion findings in 17 /83 patients (20.5 %, χ2 = 13.385, P = 0.00025). EGD after use of a duodenoscope resulted in additional lesions findings in 10 /52 patients (19.2 %, χ2 = 9.987, P = 0.00157). EGD after the use of both a linear echoendoscope and a duodenoscope resulted in additional lesions findings in 3/33 patients (9 %, χ2 = 3.219, P = 0.07). Conclusion: Non forward-viewing endoscopes miss a significant amount of incidental upper gastrointestinal lesions during pancreaticobiliary endoscopy. Performing an EGD with a gastroscope at the time of linear EUS or

  1. Validity of the New Lifestyles NL-1000 Accelerometer for Measuring Time Spent in Moderate-to-Vigorous Physical Activity in School Settings

    ERIC Educational Resources Information Center

    McMinn, David; Rowe, David A.; Stark, Michelle; Nicol, Louise

    2010-01-01

    Current interest in promoting physical activity in the school environment necessitates an inexpensive, accurate method of measuring physical activity in such settings. Additionally, it is recognized that physical activity must be of at least moderate intensity in order to yield substantial health benefits. The purpose of the study, therefore, was…

  2. Chemical Speciation of Neptunium in Spent Fuel. 1st Progress Report

    SciTech Connect

    Czerwinski, Ken; Sherman, Christi; Reed, Don

    2000-03-02

    This project will examine the chemical speciation of neptunium in spent nuclear fuel. The R&D fields covered by the project include waste host materials and actinide chemistry. Examination of neptunium is chosen since it was identified as a radionuclide of concern by the NERI workshop. Additionally, information on the chemical form of neptunium in spent fuel is lacking. The identification of the neptunium species in spent fuel would allow a greater scientific based understanding of its long-term fate and behavior in waste forms. Research to establish the application and development of X-ray synchrotrons radiation (XSR) techniques to determine the structure of aqueous, adsorbed, and solid actinide species of importance to nuclear considerations is being conducted at Argonne. These studies extend current efforts within the Chemical Technology Division at Argonne National Laboratory to investigate actinide speciation with more conventional spectroscopic and solids characterization (e.g. SEM, TEM, and XRD) methods. Our project will utilize all these techniques for determining neptunium speciation in spent fuel. We intend to determine the chemical species and oxidation state of neptunium in spent fuel and alteration phases. Different types of spent fuel will be examined. Once characterized, the chemical behavior of the identified neptunium species will be evaluated if it is not present in the literature. Special attention will be given to the behavior of the neptunium species under typical repository near-field conditions (elevated temperature, high pH, varying Eh). This will permit a timely inclusion of project results into near-field geochemical models. Additionally, project results and methodologies have applications to neptunium in the environment, or treatment of neptunium containing waste.

  3. Report on interim storage of spent nuclear fuel. Midwestern high-level radioactive waste transportation project

    SciTech Connect

    Not Available

    1993-04-01

    The report on interim storage of spent nuclear fuel discusses the technical, regulatory, and economic aspects of spent-fuel storage at nuclear reactors. The report is intended to provide legislators state officials and citizens in the Midwest with information on spent-fuel inventories, current and projected additional storage requirements, licensing, storage technologies, and actions taken by various utilities in the Midwest to augment their capacity to store spent nuclear fuel on site.

  4. Learning Style versus Time Spent Studying and Career Choice: Which Is Associated with Success in a Combined Undergraduate Anatomy and Physiology Course?

    ERIC Educational Resources Information Center

    Farkas, Gary J.; Mazurek, Ewa; Marone, Jane R.

    2016-01-01

    The VARK learning style is a pedagogical focus in health care education. This study examines relationships of course performance vs. VARK learning preference, study time, and career plan among students enrolled in an undergraduate anatomy and physiology course at a large urban university. Students (n?=?492) from the fall semester course completed…

  5. The Effects of Positive Verbal Reinforcement on the Time Spent outside the Classroom for Students with Emotional and Behavioral Disorders in a Residential Setting

    ERIC Educational Resources Information Center

    Kennedy, Christina; Jolivette, Kristine

    2008-01-01

    To more effectively instruct the entire class, teachers of students with emotional behavioral disorders (EBD) often choose to send students who display inappropriate behavior out of the room. A multiple baseline across settings was used to evaluate the effects of increasing teacher positive verbal reinforcement on the amount of time 2 students…

  6. Effects of hydraulic retention time and bioflocculant addition on membrane fouling in a sponge-submerged membrane bioreactor.

    PubMed

    Deng, Lijuan; Guo, Wenshan; Ngo, Huu Hao; Du, Bing; Wei, Qin; Tran, Ngoc Han; Nguyen, Nguyen Cong; Chen, Shiao-Shing; Li, Jianxin

    2016-06-01

    The characteristics of activated sludge and membrane fouling were evaluated in a sponge-submerged membrane bioreactor (SSMBR) at different hydraulic retention times (HRTs) (6.67, 5.33 and 4.00h). At shorter HRT, more obvious membrane fouling was caused by exacerbated cake layer formation and aggravated pore blocking. Activated sludge possessed more extracellular polymeric substances (EPS) due to excessive growth of biomass and lower protein to polysaccharide ratio in soluble microbial products (SMP). The cake layer resistance was aggravated by increased sludge viscosity together with the accumulated EPS and biopolymer clusters (BPC) on membrane surface. However, SMP showed marginal effect on membrane fouling when SSMBRs were operated at all HRTs. The SSMBR with Gemfloc® addition at the optimum HRT of 6.67h demonstrated superior sludge characteristics such as larger floc size, less SMP in mixed liquor with higher protein/polysaccharide ratio, less SMP and BPC in cake layer, thereby further preventing membrane fouling. PMID:26852274

  7. Impact of Influenza on Outpatient Visits, Hospitalizations, and Deaths by Using a Time Series Poisson Generalized Additive Model

    PubMed Central

    Guo, Ru-ning; Zheng, Hui-zhen; Ou, Chun-quan; Huang, Li-qun; Zhou, Yong; Zhang, Xin; Liang, Can-kun; Lin, Jin-yan; Zhong, Hao-jie; Song, Tie; Luo, Hui-ming

    2016-01-01

    Background The disease burden associated with influenza in developing tropical and subtropical countries is poorly understood owing to the lack of a comprehensive disease surveillance system and information-exchange mechanisms. The impact of influenza on outpatient visits, hospital admissions, and deaths has not been fully demonstrated to date in south China. Methods A time series Poisson generalized additive model was used to quantitatively assess influenza-like illness (ILI) and influenza disease burden by using influenza surveillance data in Zhuhai City from 2007 to 2009, combined with the outpatient, inpatient, and respiratory disease mortality data of the same period. Results The influenza activity in Zhuhai City demonstrated a typical subtropical seasonal pattern; however, each influenza virus subtype showed a specific transmission variation. The weekly ILI case number and virus isolation rate had a very close positive correlation (r = 0.774, P < 0.0001). The impact of ILI and influenza on weekly outpatient visits was statistically significant (P < 0.05). We determined that 10.7% of outpatient visits were associated with ILI and 1.88% were associated with influenza. ILI also had a significant influence on the hospitalization rates (P < 0.05), but mainly in populations <25 years of age. No statistically significant effect of influenza on hospital admissions was found (P > 0.05). The impact of ILI on chronic obstructive pulmonary disease (COPD) was most significant (P < 0.05), with 33.1% of COPD-related deaths being attributable to ILI. The impact of influenza on the mortality rate requires further evaluation. Conclusions ILI is a feasible indicator of influenza activity. Both ILI and influenza have a large impact on outpatient visits. Although ILI affects the number of hospital admissions and deaths, we found no consistent influence of influenza, which requires further assessment. PMID:26894876

  8. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Flight time limitations: Crew of three or... OPERATIONS Flight Time Limitations: Supplemental Operations § 121.523 Flight time limitations: Crew of three... duty for more than 30 hours. Such a crewmember is considered to be on continuous duty from the time...

  9. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  10. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  11. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  12. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... excess of seven days may be given at any time before the pilot is again scheduled for flight duty on...

  13. Case histories of West Valley spent fuel shipments: Final report

    SciTech Connect

    Not Available

    1987-01-01

    In 1983, NRC/FC initiated a study on institutional issues related to spent fuel shipments originating at the former spent fuel processing facility in West Valley, New York. FC staff viewed the shipment campaigns as a one-time opportunity to document the institutional issues that may arise with a substantial increase in spent fuel shipping activity. NRC subsequently contracted with the Aerospace Corporation for the West Valley Study. This report contains a detailed description of the events which took place prior to and during the spent fuel shipments. The report also contains a discussion of the shipment issues that arose, and presents general findings. Most of the institutional issues discussed in the report do not fall under NRC's transportation authority. The case histories provide a reference to agencies and other institutions that may be involved in future spent fuel shipping campaigns. 130 refs., 7 figs., 19 tabs.

  14. Spent fuel test project, Climax granitic stock, Nevada Test Site

    SciTech Connect

    Ramspott, L.D.

    1980-10-24

    The Spent Fuel Test-Climax (SFT-C) is a test of dry geologic storage of spent nuclear reactor fuel. The SFT-C is located at a depth of 420 m in the Climax granitic stock at the Nevada Test Site. Eleven canisters of spent commercial PWR fuel assemblies are to be stored for 3 to 5 years. Additional heat is supplied by electrical heaters, and more than 800 channels of technical information are being recorded. The measurements include rock temperature, rock displacement and stress, joint motion, and monitoring of the ventilation air volume, temperature, and dewpoint.

  15. 14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Three or more... OPERATIONS Flight Time Limitations: Flag Operations § 121.485 Flight time limitations: Three or more pilots... his base and who is a pilot on an airplane that has a crew of three or more pilots and an...

  16. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Crew of three or... OPERATIONS Flight Time Limitations: Supplemental Operations § 121.523 Flight time limitations: Crew of three... operations may schedule an airman for flight deck duty as a flight engineer, or navigator in a crew of...

  17. 14 CFR 121.521 - Flight time limitations: Crew of two pilots and one additional airman as required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight time limitations: Crew of two pilots...: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Time Limitations: Supplemental Operations § 121.521 Flight time limitations: Crew of two pilots and one...

  18. 14 CFR 121.521 - Flight time limitations: Crew of two pilots and one additional airman as required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight time limitations: Crew of two pilots...: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Time Limitations: Supplemental Operations § 121.521 Flight time limitations: Crew of two pilots and one...

  19. 14 CFR 121.521 - Flight time limitations: Crew of two pilots and one additional airman as required.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations: Crew of two pilots...: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Time Limitations: Supplemental Operations § 121.521 Flight time limitations: Crew of two pilots and one...

  20. 14 CFR 121.521 - Flight time limitations: Crew of two pilots and one additional airman as required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Crew of two pilots...: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Time Limitations: Supplemental Operations § 121.521 Flight time limitations: Crew of two pilots and one...

  1. Thermal Hydraulic Analysis of Spent Fuel Casks

    1997-10-08

    COBRA-SFS (Spent Fuel Storage) is a code for thermal-hydraulic analysis of multi-assembly spent fuel storage and transportation systems. It uses a lumped parameter finite difference approach to predict flow and temperature distributions in spent fuel storage systems and fuel assemblies, under forced and natural convection heat transfer conditions. Derived from the COBRA family of codes, which have been extensively evaluated against in-pile and out-of-pile data, COBRA-SFS retains all the important features of the COBRA codesmore » for single phase fluid analysis, and extends the range application to include problems with two-dimensional radiative and three-dimensional conductive heat transfer. COBRA-SFS has been used to analyze various single- and multi-assembly spent fuel storage systems containing unconsolidated and consolidated fuel rods, with a variety of fill media, including air, helium and vacuum. Cycle 0 of COBRA-SFS was released in 1986. Subsequent applications of the code led to development of additional capabilities, which resulted in the release of Cycle 1 in February 1989. Since then, the code has undergone an independent technical review as part of a submittal to the Nuclear Regulatory Commission for a generic license to apply the code to spent fuel storage system analysis. Modifications and improvements to the code have been combined to form Cycle 2. Cycle 3., the newest version of COBRA-SFS, has been validated and verified for transient applications, such as a storage cask thermal response to a pool fire.« less

  2. A Second Look at Neutron Resonance Transmission Analysis as a Spent Fuel NDA Technique

    SciTech Connect

    James W .Sterbentz; David L. Chichester

    2011-07-01

    Many different nondestructive analysis techniques are currently being investigated as a part of the United States Department of Energy's Next Generation Safeguards Initiative (NGSI) seeking methods to quantify plutonium in spent fuel. Neutron Resonance Transmission Analysis (NRTA) is one of these techniques. Having first been explored in the mid-1970s for the analysis of individual spent-fuel pins a second look, using advanced simulation and modeling methods, is now underway to investigate the suitability of the NRTA technique for assaying complete spent nuclear fuel assemblies. The technique is similar to neutron time-of-flight methods used for cross-section determinations but operates over only the narrow 0.1-20 eV range where strong, distinguishable resonances exist for both the plutonium (239, 240, 241,242Pu) and uranium (235,236,238U) isotopes of interest in spent fuel. Additionally, in this energy range resonances exists for six important fission products (99Tc, 103Rh, 131Xe, 133Cs, 145Nd, and 152Sm) which provide additional information to support spent fuel plutonium assay determinations. Initial modeling shows excellent agreement with previously published experimental data for measurements of individual spent-fuel pins where plutonium assays were demonstrated to have a precision of 2-4%. Within the simulation and modeling analyses of this project scoping studies have explored fourteen different aspects of the technique including the neutron source, drift tube configurations, and gross neutron transmission as well as the impacts of fuel burn up, cooling time, and fission-product interferences. These results show that NRTA may be a very capable experimental technique for spent-fuel assay measurements. The results suggest sufficient transmission strength and signal differentiability is possible for assays through up to 8 pins. For an 8-pin assay (looking at an assembly diagonally), 64% of the pins in a typical 17 ? 17 array of a pressurized water reactor fuel

  3. Loss of spent fuel pool cooling PRA: Model and results

    SciTech Connect

    Siu, N.; Khericha, S.; Conroy, S.; Beck, S.; Blackman, H.

    1996-09-01

    This letter report documents models for quantifying the likelihood of loss of spent fuel pool cooling; models for identifying post-boiling scenarios that lead to core damage; qualitative and quantitative results generated for a selected plant that account for plant design and operational practices; a comparison of these results and those generated from earlier studies; and a review of available data on spent fuel pool accidents. The results of this study show that for a representative two-unit boiling water reactor, the annual probability of spent fuel pool boiling is 5 {times} 10{sup {minus}5} and the annual probability of flooding associated with loss of spent fuel pool cooling scenarios is 1 {times} 10{sup {minus}3}. Qualitative arguments are provided to show that the likelihood of core damage due to spent fuel pool boiling accidents is low for most US commercial nuclear power plants. It is also shown that, depending on the design characteristics of a given plant, the likelihood of either: (a) core damage due to spent fuel pool-associated flooding, or (b) spent fuel damage due to pool dryout, may not be negligible.

  4. FIELD-DEPLOYABLE SAMPLING TOOLS FOR SPENT NUCLEAR FUEL INTERROGATION IN LIQUID STORAGE

    SciTech Connect

    Berry, T.; Milliken, C.; Martinez-Rodriguez, M.; Hathcock, D.; Heitkamp, M.

    2012-09-12

    Methodology and field deployable tools (test kits) to analyze the chemical and microbiological condition of aqueous spent fuel storage basins and determine the oxide thickness on the spent fuel basin materials were developed to assess the corrosion potential of a basin. this assessment can then be used to determine the amount of time fuel has spent in a storage basin to ascertain if the operation of the reactor and storage basin is consistent with safeguard declarations or expectations and assist in evaluating general storage basin operations. The test kit was developed based on the identification of key physical, chemical and microbiological parameters identified using a review of the scientific and basin operations literature. The parameters were used to design bench scale test cells for additional corrosion analyses, and then tools were purchased to analyze the key parameters. The tools were used to characterize an active spent fuel basin, the Savannah River Site (SRS) L-Area basin. The sampling kit consisted of a total organic carbon analyzer, an YSI multiprobe, and a thickness probe. The tools were field tested to determine their ease of use, reliability, and determine the quality of data that each tool could provide. Characterization confirmed that the L Area basin is a well operated facility with low corrosion potential.

  5. Assessment of spent fuel cooling

    SciTech Connect

    Ibarra, J.G.; Jones, W.R.; Lanik, G.F.

    1997-02-01

    The paper presents the methodology, the findings, and the conclusions of a study that was done by the Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) on loss of spent fuel pool cooling. The study involved an examination of spent fuel pool designs, operating experience, operating practices, and procedures. AEOD`s work was augmented in the area of statistics and probabilistic risk assessment by experts from the Idaho Nuclear Engineering Laboratory. Operating experience was integrated into a probabilistic risk assessment to gain insight on the risks from spent fuel pools.

  6. Evaluation of gold nanoparticles as the additive in real-time polymerase chain reaction with SYBR Green I dye

    NASA Astrophysics Data System (ADS)

    Yang, Wenchao; Mi, Lijuan; Cao, Xueyan; Zhang, Xiaodong; Fan, Chunhai; Hu, Jun

    2008-06-01

    Gold nanoparticles (AuNPs) have been proven to be able to improve the specificity or increase the efficiency of a polymerase chain reaction (PCR) when a suitable amount of AuNPs was used. However, there is still a lack of systematic evaluation of AuNPs in real-time PCR. In this study, DNA degradation and the fluorescence quenching effect of AuNPs were first tested in real-time PCR. Then two different kinds of Taq DNA polymerase, native and recombinant Taq polymerase, were employed to evaluate the AuNPs' effect on the threshold cycle (CT) values, standard curves and melting curves in real-time PCR. Different ratios of the amount of native Taq DNA polymerase to the amount of AuNPs were also tested. It was found that AuNPs could be applied in real-time PCR with correlation coefficient R2>0.989. The combination of 2.09 nM AuNPs with 3.75 U of native Taq DNA polymerase could make the amplification curves shift to the left and enhance the efficiency of the real-time PCR (0.628 39 without AuNPs compared with 0.717 89 with 2.09 nM AuNPs), thus enabling faster detection in comparison with those of control samples. However, no improvement ability of AuNPs was found in real-time PCR based on recombinant rTaq DNA polymerase. Besides, the results suggest that a complex interaction exists between AuNPs and native Taq DNA polymerase.

  7. 77 FR 23239 - Bryant Mountain, LLC; Notice of Additional Scoping Meetings, Extension of Time To File Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ... Time To File Comments on the PAD and Scoping Document, and Identification of Issues and Associated... comments on the Pre- Application Document (PAD) and Scoping Document 1 (SD1). b. Type of Filing: Notice of..., filed with the Commission a PAD (including a proposed process plan and schedule), pursuant to 18 CFR...

  8. Optimized Liquid-Liquid Extractive Rerefining of Spent Lubricants

    PubMed Central

    Kamal, Muhammad Ashraf; Khan, Fasihullah

    2014-01-01

    Central composite design methodology has been employed to model the sludge yield data obtained during liquid-liquid extractive rerefining of spent lubricants using an alcohol (1-butanol) and a ketone (methyl ethyl ketone) as prospective solvents. The study has resulted in two reasonably accurate multivariate process models that relate the sludge yield (R2 = 0.9065 and 0.9072 for alcohol and ketone, resp.) to process variables (settling time t, operating temperature T, and oil to solvent ratio r). Construction of such models has allowed the maximization of the sludge yield (more than 8% and 3% in case of alcohol and ketone, resp.) so that the extraction of useable oil components from spent lubricants can economically be performed under extremely mild conditions (t = 16.7 h, T = 10°C, and r = 2) and fairly moderate conditions (t = 26.6 h, T = 10°C, and r = 5) established for the alcohol and ketone correspondingly. Based on these performance parameters alcohol appears to be superior over ketone for this extraction process. Additionally extractive treatment results in oil stocks with lesser quantity of environmentally hazardous polyaromatic hydrocarbons that are largely left in the separated sludge. PMID:24688388

  9. Active Interrogation for Spent Fuel

    SciTech Connect

    Swinhoe, Martyn Thomas; Dougan, Arden

    2015-11-05

    The DDA instrument for nuclear safeguards is a fast, non-destructive assay, active neutron interrogation technique using an external 14 MeV DT neutron generator for characterization and verification of spent nuclear fuel assemblies.

  10. Chimpanzees remember the results of one-by-one addition of food items to sets over extended time periods.

    PubMed

    Beran, Michael J; Beran, Mary M

    2004-02-01

    Four chimpanzees were highly accurate in selecting the larger of two concurrent accumulations of bananas in two opaque containers over a span of 20 min. One at a time, bananas were placed into the containers, which were outside the chimpanzees' cages. The chimpanzees never saw more than one banana at a time, and there were no cues indicating the locations of the bananas after they were placed into the containers. The performance of these animals matched that of human infants and young children in similar tests. The chimpanzees were successful even when the sets to be compared were sufficiently large (5 vs. 8, 5 vs. 10, and 6 vs. 10) to cast doubt on the possibility that the chimpanzees were using an object file mechanism. These chimpanzees are the first nonhuman animals to demonstrate extended memory for accumulated quantity. PMID:14738515

  11. Intensifying instruction: Does additional instructional time make a difference for the most at-risk first graders?

    PubMed

    Harn, Beth A; Linan-Thompson, Sylvia; Roberts, Gregory

    2008-01-01

    Research is clear on the benefit of early intervention efforts and the importance of intensive instructional supports; however, understanding which features to intensify is less clear. General intervention features of group size, instructional delivery, and time are areas schools can consider manipulating to intensify instruction. Also, each of these features can vary along a continuum making them easier or more challenging for schools to implement. What is unclear is if implementing very intensive interventions early in school (first grade), which require significantly more school resources, provides accordingly accelerated student learning. This article investigates the role of intensifying instructional time for the most at-risk first graders in schools implementing research-based instructional and assessment practices within multitiered instructional support systems. Results indicate that students receiving more intensive intervention made significantly more progress across a range of early reading measures. Intervention features, limitations, recommendations for practice, and implications for treatment resisters are discussed. PMID:18354932

  12. Transportation of spent MTR fuels

    SciTech Connect

    Raisonnier, D.

    1997-08-01

    This paper gives an overview of the various aspects of MTR spent fuel transportation and provides in particular information about the on-going shipment of 4 spent fuel casks to the United States. Transnucleaire is a transport and Engineering Company created in 1963 at the request of the French Atomic Energy Commission. The company followed the growth of the world nuclear industry and has now six subsidiaries and affiliated companies established in countries with major nuclear programs.

  13. Pyrolysis of Spent Ion Exchange Resins - 12210

    SciTech Connect

    Braehler, Georg; Slametschka, Rainer

    2012-07-01

    Organic ion exchangers (IEX) play a major and increasing role in the reactor coolant and other water purification processes. During their operation time they receive significant amounts of radioactivity, making their disposal, together with their organic nature, as medium active waste challenging. Processes applied so far do not eliminate the organic matter, which is unwanted in disposal facilities, or, if high temperatures are applied, raise problems with volatile radionuclides. NUKEM Technologies offers their well introduces process for the destruction of spent solvent (TBP), the pebble bed pyrolysis, now for the treatment of spent IEX (and other problematic waste), with the following benefits: the pyrolysis product is free of organic matter, and the operation temperature with approx. 500 deg. C keeps Cs radionuclides completely in the solid residue. (authors)

  14. Spent Nuclear Fuel project, project management plan

    SciTech Connect

    Fuquay, B.J.

    1995-10-25

    The Hanford Spent Nuclear Fuel Project has been established to safely store spent nuclear fuel at the Hanford Site. This Project Management Plan sets forth the management basis for the Spent Nuclear Fuel Project. The plan applies to all fabrication and construction projects, operation of the Spent Nuclear Fuel Project facilities, and necessary engineering and management functions within the scope of the project

  15. Modeling of time dependent localized flow shear stress and its impact on cellular growth within additive manufactured titanium implants

    PubMed Central

    Zhang, Ziyu; Yuan, Lang; Lee, Peter D; Jones, Eric; Jones, Julian R

    2014-01-01

    Bone augmentation implants are porous to allow cellular growth, bone formation and fixation. However, the design of the pores is currently based on simple empirical rules, such as minimum pore and interconnects sizes. We present a three-dimensional (3D) transient model of cellular growth based on the Navier–Stokes equations that simulates the body fluid flow and stimulation of bone precursor cellular growth, attachment, and proliferation as a function of local flow shear stress. The model's effectiveness is demonstrated for two additive manufactured (AM) titanium scaffold architectures. The results demonstrate that there is a complex interaction of flow rate and strut architecture, resulting in partially randomized structures having a preferential impact on stimulating cell migration in 3D porous structures for higher flow rates. This novel result demonstrates the potential new insights that can be gained via the modeling tool developed, and how the model can be used to perform what-if simulations to design AM structures to specific functional requirements. PMID:24664988

  16. Performance analysis for time-frequency MUSIC algorithm in presence of both additive noise and array calibration errors

    NASA Astrophysics Data System (ADS)

    Khodja, Mohamed; Belouchrani, Adel; Abed-Meraim, Karim

    2012-12-01

    This article deals with the application of Spatial Time-Frequency Distribution (STFD) to the direction finding problem using the Multiple Signal Classification (MUSIC)algorithm. A comparative performance analysis is performed for the method under consideration with respect to that using data covariance matrix when the received array signals are subject to calibration errors in a non-stationary environment. An unified analytical expression of the Direction Of Arrival (DOA) error estimation is derived for both methods. Numerical results show the effect of the parameters intervening in the derived expression on the algorithm performance. It is particularly observed that for low Signal to Noise Ratio (SNR) and high Signal to sensor Perturbation Ratio (SPR) the STFD method gives better performance, while for high SNR and for the same SPR both methods give similar performance.

  17. Zoom-TOFMS: addition of a constant-momentum-acceleration "zoom" mode to time-of-flight mass spectrometry.

    PubMed

    Dennis, Elise A; Gundlach-Graham, Alexander W; Ray, Steven J; Enke, Christie G; Barinaga, Charles J; Koppenaal, David W; Hieftje, Gary M

    2014-11-01

    In this study, we demonstrate the performance of a new mass spectrometry concept called zoom time-of-flight mass spectrometry (zoom-TOFMS). In our zoom-TOFMS instrument, we combine two complementary types of TOFMS: conventional, constant-energy acceleration (CEA) TOFMS and constant-momentum acceleration (CMA) TOFMS to provide complete mass-spectral coverage as well as enhanced resolution and duty factor for a narrow, targeted mass region, respectively. Alternation between CEA- and CMA-TOFMS requires only that electrostatic instrument settings (i.e., reflectron and ion optics) and ion acceleration conditions be changed. The prototype zoom-TOFMS instrument has orthogonal-acceleration geometry, a total field-free distance of 43 cm, and a direct-current glow-discharge ionization source. Experimental results demonstrate that the CMA-TOFMS "zoom" mode offers resolution enhancement of 1.6 times over single-stage acceleration CEA-TOFMS. For the atomic mass range studied here, the maximum resolving power at full-width half-maximum observed for CEA-TOFMS was 1,610 and for CMA-TOFMS the maximum was 2,550. No difference in signal-to-noise (S/N) ratio was observed between the operating modes of zoom-TOFMS when both were operated at equivalent repetition rates. For a 10-kHz repetition rate, S/N values for CEA-TOFMS varied from 45 to 990 and from 67 to 10,000 for CMA-TOFMS. This resolution improvement is the result of a linear TOF-to-mass scale and the energy-focusing capability of CMA-TOFMS. Use of CMA also allows ions outside a given m/z range to be rejected by simple ion-energy barriers to provide a substantial improvement in duty factor. PMID:24866712

  18. Effect of Helium Accumulation on the Spent Fuel Microstructure

    SciTech Connect

    Ferry, Cecile; Piron, Jean-Paul; Stout, Ray

    2007-07-01

    In a nuclear spent fuel repository, the aqueous rapid release of radio-activity from exposed spent fuel surfaces will depend on the pellet microstructure at the arrival time of water into the disposal container. Research performed on spent fuel evolution in a closed system has shown that the evolution of microstructure under disposal conditions should be governed by the cumulated {alpha}-decay damage and the subsequent helium behavior. The evolution of fission gas bubble characteristics under repository conditions has to be assessed. In UO{sub 2} fuels with a burnup of 47.5 GWd/t, the pressure in fission gas bubbles, including the pressure increase from {alpha}-decay helium atoms, is not expected to reach the critical bubble pressure that will cause failure, thus micro-cracking in UO{sub 2} spent fuel grains is not expected. (authors)

  19. Application of ALARA principles to shipment of spent nuclear fuel

    SciTech Connect

    Greenborg, J.; Brackenbush, L.W.; Murphy, D.W. Burnett, R.A.; Lewis, J.R.

    1980-05-01

    The public exposure from spent fuel shipment is very low. In view of this low exposure and the perfect safety record for spent fuel shipment, existing systems can be considered satisfactory. On the other hand, occupational exposure reduction merits consideration and technology improvement to decrease dose should concentrate on this exposure. Practices that affect the age of spent fuel in shipment and the number of times the fuel must be shipped prior to disposal have the largest impact. A policy to encourage a 5-year spent fuel cooling period prior to shipment coupled with appropriate cask redesign to accommodate larger loads would be consistent with ALARA and economic principles. And finally, bypassing high population density areas will not in general reduce shipment dose.

  20. Spent Nuclear Fuel (SNF) Project Acceptance Criteria for Light Water Reactor Spent Fuel Storage System [OCRWM PER REV2

    SciTech Connect

    JOHNSON, D.M.

    2000-12-20

    As part of the decommissioning of the 324 Building Radiochemical Engineering Cells there is a need to remove commercial Light Water Reactor (LWR) spent nuclear fuel (SNF) presently stored in these hot cells. To enable fuel removal from the hot cells, the commercial LWR SNF will be packaged and shipped to the 200 Area Interim Storage Area (ISA) in a manner that satisfies site requirements for SNF interim storage. This document identifies the criteria that the 324 Building Radiochemical Engineering Cell Clean-out Project must satisfy for acceptance of the LWR SNF by the SNF Project at the 200 Area ISA. In addition to the acceptance criteria identified herein, acceptance is contingent on adherence to applicable Project Hanford Management Contract requirements and procedures in place at the time of work execution.

  1. Space Takes Time: Concentration Dependent Output Codes from Primary Olfactory Networks Rapidly Provide Additional Information at Defined Discrimination Thresholds

    PubMed Central

    Daly, Kevin C.; Bradley, Samual; Chapman, Phillip D.; Staudacher, Erich M.; Tiede, Regina; Schachtner, Joachim

    2016-01-01

    As odor concentration increases, primary olfactory network representations expand in spatial distribution, temporal complexity and duration. However, the direct relationship between concentration dependent odor representations and the psychophysical thresholds of detection and discrimination is poorly understood. This relationship is absolutely critical as thresholds signify transition points whereby representations become meaningful to the organism. Here, we matched stimulus protocols for psychophysical assays and intracellular recordings of antennal lobe (AL) projection neurons (PNs) in the moth Manduca sexta to directly compare psychophysical thresholds and the output representations they elicit. We first behaviorally identified odor detection and discrimination thresholds across an odor dilution series for a panel of structurally similar odors. We then characterized spatiotemporal spiking patterns across a population of individually filled and identified AL PNs in response to those odors at concentrations below, at, and above identified thresholds. Using spatial and spatiotemporal based analyses we observed that each stimulus produced unique representations, even at sub-threshold concentrations. Mean response latency did not decrease and the percent glomerular activation did not increase with concentration until undiluted odor. Furthermore, correlations between spatial patterns for odor decreased, but only significantly with undiluted odor. Using time-integrated Euclidean distance (ED) measures, we determined that added spatiotemporal information was present at the discrimination but not detection threshold. This added information was evidenced by an increase in integrated distance between the sub-detection and discrimination threshold concentrations (of the same odor) that was not present in comparison of the sub-detection and detection threshold. After consideration of delays for information to reach the AL we find that it takes ~120–140 ms for the AL to

  2. Detonation of highly dilute porous explosives; II: Influence of inert additives on the structure of the front, the parameters, and the reaction time

    SciTech Connect

    Shvedov, K.K.; Aniskin, A.I.; Dremin, A.N.; Il'in, A.N.

    1982-06-01

    For the detonation of porous explosives with inert additives, as for the detonation of individual porous explosives, the basic postulates and conclusions of the modern gasdynamic theory of detonation are valid. The influence of solid, refractory inert additives on the decomposition mechanism of porous explosives depends on the individual properties of the explosives and mainly on the dispersity of the additives. With the elimination of pronounced heating of the additives in mixtures with TNT, a certain positive influence on the appearance of decomposition sources and the total reaction time is observed. In cases with hexogen, no such influence is observed, which is evidently the result of physical inhomogeneity of the porous structure of the charge and the sufficiently high detonation pressures of the mixtures. The basic influence of inert additives on the critical diameter, front structure, detonation parameters, and reaction time of porous explosives is exerted through processes of energy absorption in the reaction region and factors leading to energy losses may lead to ambiguity of the detonation conditions in a system with specified chemical potential energy. The state of the additive in the reaction region must be taken into account for reliable theoretical description of the detonation conditions of porous explosives with a large content of inert additives.

  3. Combined action of time-delay and colored cross-associated multiplicative and additive noises on stability and stochastic resonance for a stochastic metapopulation system

    NASA Astrophysics Data System (ADS)

    Wang, Kang-Kang; Zong, De-Cai; Wang, Ya-Jun; Li, Sheng-Hong

    2016-05-01

    In this paper, the transition between the stable state of a big density and the extinction state and stochastic resonance (SR) for a time-delayed metapopulation system disturbed by colored cross-correlated noises are investigated. By applying the fast descent method, the small time-delay approximation and McNamara and Wiesenfeld's SR theory, we investigate the impacts of time-delay, the multiplicative, additive noises and colored cross-correlated noise on the SNR and the shift between the two states of the system. Numerical results show that the multiplicative, additive noises and time-delay can all speed up the transition from the stable state to the extinction state, while the correlation noise and its correlation time can slow down the extinction process of the population system. With respect to SNR, the multiplicative noise always weakens the SR effect, while noise correlation time plays a dual role in motivating the SR phenomenon. Meanwhile, time-delay mainly plays a negative role in stimulating the SR phenomenon. Conversely, it could motivate the SR effect to increase the strength of the cross-correlation noise in the SNR-β plot, while the increase of additive noise intensity will firstly excite SR, and then suppress the SR effect.

  4. Spent Fuel Working Group Report. Volume 1

    SciTech Connect

    O`Toole, T.

    1993-11-01

    The Department of Energy is storing large amounts of spent nuclear fuel and other reactor irradiated nuclear materials (herein referred to as RINM). In the past, the Department reprocessed RINM to recover plutonium, tritium, and other isotopes. However, the Department has ceased or is phasing out reprocessing operations. As a consequence, Department facilities designed, constructed, and operated to store RINM for relatively short periods of time now store RINM, pending decisions on the disposition of these materials. The extended use of the facilities, combined with their known degradation and that of their stored materials, has led to uncertainties about safety. To ensure that extended storage is safe (i.e., that protection exists for workers, the public, and the environment), the conditions of these storage facilities had to be assessed. The compelling need for such an assessment led to the Secretary`s initiative on spent fuel, which is the subject of this report. This report comprises three volumes: Volume I; Summary Results of the Spent Fuel Working Group Evaluation; Volume II, Working Group Assessment Team Reports and Protocol; Volume III; Operating Contractor Site Team Reports. This volume presents the overall results of the Working Group`s Evaluation. The group assessed 66 facilities spread across 11 sites. It identified: (1) facilities that should be considered for priority attention. (2) programmatic issues to be considered in decision making about interim storage plans and (3) specific vulnerabilities for some of these facilities.

  5. An underwater neutron coincidence counter for measurement of spent fuels

    SciTech Connect

    Staples, P.; Halbig, J.; Lestone, J.; Sprinkle, J.

    1999-07-01

    An underwater neutron coincident counter has been designed and constructed for the measurement of spent nuclear fuel--the spent-fuel coincident counter (SFCC). The SFCC is a medium-detection-efficiency design that incorporates an ionization chamber (IC) for gamma-ray dose evaluation from the spent nuclear fuel. The absolute neutron detection efficiency is 14.5% for {sup 252}Cf sources. The SFCC is hermetically sealed, as it is installed {approximately}5 m below water level in a spent-fuel storage pond. There are 20 {sup 3}He tubes arranged within a polyethylene ring in a single band. There is an inner ring of 6.8 cm of lead to provide shielding from the fission product gamma rays. A single IC is primarily used to determine the dose impinging upon the {sup 3}He tubes and to determine the appropriate operational parameters to avoid gamma-ray pile effects in the {sup 3}He tubes. To further minimize gamma-ray pileup effects, each {sup 3}He tube is connected to a PDT110A preamplifier. The single and double neutron count rates, in addition to the IC measurement information from the SFCC, are used to determine the Pu mass of the spent-fuel assemblies and the decay heat and for classification of the assembly type. This information is required such that safety criteria are met for the safe packaging of the spent-fuel assemblies.

  6. Time Students Spend Working at Home for School

    ERIC Educational Resources Information Center

    Wagner, Petra; Schober, Barbara; Spiel, Christiane

    2008-01-01

    The paper presents three studies which deal with the time students spend working at home for school. In addition, the paper focuses on the distribution of time investment over the course of a week and on the relationship between academic achievement and time spent working at home for school. In sum, 824 students with an average age of 15 years…

  7. Assessing direct analysis in real-time-mass spectrometry (DART-MS) for the rapid identification of additives in food packaging.

    PubMed

    Ackerman, L K; Noonan, G O; Begley, T H

    2009-12-01

    The ambient ionization technique direct analysis in real time (DART) was characterized and evaluated for the screening of food packaging for the presence of packaging additives using a benchtop mass spectrometer (MS). Approximate optimum conditions were determined for 13 common food-packaging additives, including plasticizers, anti-oxidants, colorants, grease-proofers, and ultraviolet light stabilizers. Method sensitivity and linearity were evaluated using solutions and characterized polymer samples. Additionally, the response of a model additive (di-ethyl-hexyl-phthalate) was examined across a range of sample positions, DART, and MS conditions (temperature, voltage and helium flow). Under optimal conditions, molecular ion (M+H+) was the major ion for most additives. Additive responses were highly sensitive to sample and DART source orientation, as well as to DART flow rates, temperatures, and MS inlet voltages, respectively. DART-MS response was neither consistently linear nor quantitative in this setting, and sensitivity varied by additive. All additives studied were rapidly identified in multiple food-packaging materials by DART-MS/MS, suggesting this technique can be used to screen food packaging rapidly. However, method sensitivity and quantitation requires further study and improvement. PMID:19753496

  8. Dormant Cells of Staphylococcus aureus Are Resuscitated by Spent Culture Supernatant

    PubMed Central

    Pascoe, Ben; Dams, Lucy; Wilkinson, Tom S.; Harris, Llinos G.; Bodger, Owen; Mack, Dietrich; Davies, Angharad P.

    2014-01-01

    We describe the first in vitro model of dormancy in Staphylococcus aureus, showing that cells are generated which can be resuscitated by addition of spent medium supernatant taken from cultures of the same organism. Over 30 days, culturable counts in dormant cultures of S. aureus SH1000 fell from 106–107 cfu/ml to <10 cfu/ml as measured by the Most Probable Number method in liquid culture, while total counts as determined by microscopy, and supported by data from RT-qPCR, remained around 106–107 cells/ml. Supplementing cultures with 25–50% spent medium resulted in a >600-fold increase in bacterial growth. Resuscitation was a specific effect, greatly reduced by boiling or addition of trypsin to the spent supernatant. Supernatant also effected a reduction in lag phase of dormant cultures. SEM demonstrated the presence of small coccoid cells in dormant cultures. The results are similar to those seen with resuscitation promoting factors (Rpfs) in actinobacteria. This is the first time resuscitation has been demonstrated in Staphylococcus aureus, which is an important human pathogen. A better understanding of control and reactivation of dormant cells could lead to major improvements in managing staphylococcal infections; resuscitation could be an important step in restoring susceptibility to antibiotic treatment. PMID:24523858

  9. Generalized additive models with interval-censored data and time-varying covariates: application to human immunodeficiency virus infection in hemophiliacs.

    PubMed

    Bacchetti, Peter; Quale, Christopher

    2002-06-01

    We describe a method for extending smooth nonparametric modeling methods to time-to-event data where the event may be known only to lie within a window of time. Maximum penalized likelihood is used to fit a discrete proportional hazards model that also models the baseline hazard, and left-truncation and time-varying covariates are accommodated. The implementation follows generalized additive modeling conventions, allowing both parametric and smooth terms and specifying the amount of smoothness in terms of the effective degrees of freedom. We illustrate the method on a well-known interval-censored data set on time of human immunodeficiency virus infection in a multicenter study of hemophiliacs. The ability to examine time-varying covariates, not available with previous methods, allows detection and modeling of nonproportional hazards and use of a time-varying covariate that fits the data better and is more plausible than a fixed alternative. PMID:12071419

  10. Microbiological and physicochemical characterization of dry-cured Halal goat meat. Effect of salting time and addition of olive oil and paprika covering.

    PubMed

    Cherroud, Sanâa; Cachaldora, Aida; Fonseca, Sonia; Laglaoui, Amin; Carballo, Javier; Franco, Inmaculada

    2014-10-01

    The objective of this work was to define a simple technological process for dry-cured Halal goat meat elaboration. The aims of this study were to analyze physicochemical parameters and to enumerate the microbial population at the end of the different manufacturing processes (two salting times and the addition of olive oil and paprika covering) on 36 units of meat product. A total of 532 strains were isolated from several selective culture media and then identified using classical and molecular methods. In general, salt effect and the addition of olive oil and paprika were significant for all the studied microbial groups as well as on NaCl content and water activity. Molecular analysis proves that staphylococci, especially Staphylococcus xylosus and Staphylococcus equorum, were the most common naturally occurring microbiota. The best manufacturing process would be obtained with a longer salting time and the addition of the olive oil and paprika covering. PMID:24950081

  11. GNS spent fuel cask experience

    SciTech Connect

    Weh, R. )

    1993-05-01

    The Gesellschaft fuer Nuklear-Service mbH (GNS), which is owned by German utilities, is responsible for the management of spent fuel and nuclear waste on behalf of the German utilities operating nuclear power plants. This paper describes the spent reactor fuel and waste shipping and/or storage casks that GNS manufacturers for nuclear facilities in Germany, and worldwide. So far more than 30 different casks have been produced in quantities ranging from one to several hundred of each type. GNS participates in the German Support Program to assist the International Atomic Energy Agency (IAEA) in developing verification procedures for dry storage casks containing spent fuel. This activity is also summarized.

  12. Spent-fuel-storage alternatives

    SciTech Connect

    Not Available

    1980-01-01

    The Spent Fuel Storage Alternatives meeting was a technical forum in which 37 experts from 12 states discussed storage alternatives that are available or are under development. The subject matter was divided into the following five areas: techniques for increasing fuel storage density; dry storage of spent fuel; fuel characterization and conditioning; fuel storage operating experience; and storage and transport economics. Nineteen of the 21 papers which were presented at this meeting are included in this Proceedings. These have been abstracted and indexed. (ATT)

  13. Spent graphite fuel element processing

    SciTech Connect

    Holder, N.D.; Olsen, C.W.

    1981-07-01

    The Department of Energy currently sponsors two programs to demonstrate the processing of spent graphite fuel elements. General Atomic in San Diego operates a cold pilot plant to demonstrate the processing of both US and German high-temperature reactor fuel. Exxon Nuclear Idaho Company is demonstrating the processing of spent graphite fuel elements from Rover reactors operated for the Nuclear Rocket Propulsion Program. This work is done at Idaho National Engineering Laboratory, where a hot facility is being constructed to complete processing of the Rover fuel. This paper focuses on the graphite combustion process common to both programs.

  14. Crystallization of calcium carbonate (CaCO3) in a flowing system: Influence of Cu2+ additives on induction time and crystalline phase transformation

    NASA Astrophysics Data System (ADS)

    Usmany, Y.; Putranto, W. A.; Bayuseno, A. P.; Muryanto, S.

    2016-04-01

    Scaling of calcium carbonate (CaCO3) is commonly found in piping systems in oil, gas, desalination and other chemical processes. The scale may create technical problems, leading to the reduction of heat transfer, increase of energy consumption and unscheduled equipment shutdown. This paper presents crystallization scaling experiments and evaluation of the effect of Cu2+ additives on the induction time and calcium carbonate transformation. The crystals precursors were prepared using equimolar of CaCl2 and Na2CO3 resulted in concentrations of 3000 ppm Ca2+ in the solution. The Cu2+ in amounts of 0, 1 and 10 ppm was separately added in the solution. The flow rates (20, 35, and 60 mL/min) and elevated temperatures (27, 35 and 45°C) were selected in the study. The induction time for crystallization of CaCO3 was observed by measuring the solution conductivity over time, while the phase transformation of calcium carbonate was examined by XRD method and SEM/EDX. It was found that the conductivity remained steady for a certain period reflecting to the induction time of crystal formation, and then decreased sharply afterwards,. The induction time was increased from 34 and 48 minutes in the presence of Cu additives (1 and 10 ppm), depending on the flow rates and temperature observed. In all the experiments, the Cu2+ addition leads to the reduction of mass of crystals. Apparently, the presence of Cu2+ could inhibit the CaCO3 crystallization. In the absence of Cu2+ and at elevated temperature, the crystals obtained were a mixture of vaterite and calcite. In the presence of Cu2+ and at elevated temperature, the crystals formed were aragonite and calcite. Here, the presence of Cu2+ additives might have controlled the crystal transformation of CaCO3.

  15. Growth behavior of additional offspring with a beneficial reversal allele in the asymmetric sharply-peaked landscape in the coupled discrete-time mutation-selection model

    NASA Astrophysics Data System (ADS)

    Gill, Wonpyong

    2013-01-01

    The probability of additional offspring with a beneficial reversal allele for growing to a size NC for a range of population sizes N, sequence lengths L, selective advantages s, and measuring parameters C was calculated for a haploid, asexual population in the coupled discrete-time mutation-selection model in an asymmetric sharply-peaked landscape with a positive selective advantage of the reversal allele over the optimal allele. The growing probability in the stochastic region was inversely proportional to the measuring parameter when C < 1 /Ns, bent when C ≈ 1/ Ns and saturated when C > 1/ Ns. The crossing time and the time dependence of the increase in relative density of the reversal allele in the coupled discrete-time mutation-selection model was approximated using the Wright-Fisher two-allele model with the same selective advantage and corresponding effective mutation rate. The growth behavior of additional offspring with the reversal allele in the asymmetric sharply-peaked landscape in the coupled discrete-time mutation-selection model was controlled by the selective advantage of the reversal allele compared to the optimal allele and could be described by using the Wright-Fisher two-allele model, in spite of there being many other alleles with lower fitness, and in spite of there being two alleles, the optimal and reversal allele, separated by a low-fitness valley with a tunable depth and width.

  16. Simulation of differential die-away instrument’s response to asymmetrically burned spent nuclear fuel

    DOE PAGESBeta

    Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; Svard, Staffan Jacobsson; Jansson, Peter; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-03-04

    Here, previous simulation studies of Differential Die–Away (DDA) instrument’s response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument’s response to interrogation of asymmetricallymore » burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs.« less

  17. A FAST BREEDER REACTOR SPENT FUEL MEASUREMENTS PROGRAM FOR BN-350 REACTOR

    SciTech Connect

    P. STAPLES; J. HALBIG; ET AL

    1999-04-01

    A project to verify the fissile content of fast breeder reactor spent nuclear fuel is underway in the Republic of Kasakhstan. There are a variety of assembly types with different irradiation histories and profiles in the reactor that require a variety of measurement and analysis procedures. These procedures will be discussed and compared as will the general process that has been designed to resolve any potential measurement discrepancies. The underwater counter is part of a system that is designed to assist the International Atomic Energy Agency (IAEA) in maintaining continuity of knowledge from the time of measurement until the measured item is placed in a welded container with a unique identification. In addition to satisfying IAEA requirements for the spent nuclear fuel, this measurement program is able to satisfy some of the measurement requirements for the Kasakhstan Atomic Energy Agency concerning the repackaging of the spent nuclear fuel into a standard canister. The project is currently operational in a mode requiring the IAEA's continuous presence.

  18. Spent fuel data for waste storage programs

    SciTech Connect

    Greene, E M

    1980-09-01

    Data on LWR spent fuel were compiled for dissemination to participants in DOE-sponsored waste storage programs. Included are mechanical descriptions of the existing major types of LWR fuel assemblies, spent LWR fuel fission product inventories and decay heat data, and inventories of LWR spent fuel currently in storage, with projections of future quantities.

  19. Application of spent fuel treatment technology to plutonium immobilization

    SciTech Connect

    McPheeters, C.C; Ackerman, J.P.; Gay, E.C., Johnson, G.K.

    1996-05-01

    The purpose of the electrometallurgical treatment technology being developed at Argonne National Laboratory (ANL) is to convert certain spent nuclear fuels into waste forms that are suitable for disposal in a geological repository for nuclear waste. The spent fuels of interest are those that cannot be safely stored for a long time in their current condition, and those that cannot be qualified for repository disposal. This paper explores the possibility of applying this electrometallurgical treatment technology to immobilization of surplus fissile materials, primarily plutonium. Immobilization of surplus fissile materials by electrometallurgical treatment could be done in the same facilities, at the same time. and in the same equipment as the proposed treatment of the present inventory of spent nuclear fuel. The cost and schedule savings of this simultaneous treatment scheme would be significant.

  20. Status of spent-fuel shipping cask development

    SciTech Connect

    Hall, I.K.; Hinschberger, T.S.

    1989-01-01

    The purpose of the Cask Systems Development Program is to develop a variety of cask systems that can safely and economically transport commercial spent fuel and high-level waste from the generating sites to a federal geologic repository or monitored retrievable storage (MRS) facility. This paper is limited to a discussion of the status of from-reactor spent-fuel cask development; future cask development plans include MRS-to-repository casks, specialty casks for nonstandard spent fuel and nonfuel materials, and defense high-level waste casks. Spent-fuel casks must be available in the late 1990s to support the U.S. Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM) shipments from utilities. DOE-Idaho, with the support of EG G Idaho, Inc., Sandia National Laboratories, and selected cask developing contractors, has been assigned the responsibility for developing a new generation of cask systems. Four categories of spent fuel casks were initially proposed: (1) legal weight truck (LWT) casks (2) overweight truck (OWT) casks (3) rail/barge (R/B) casks (4) dual purpose (DP) storage/transport casks. Casks are being designed for reduced occupational radiation exposure at the receiving facility by facilitating the use of remote handling equipment. Automation of remote handling systems may be used to reduce cask turnaround time. Reducing turnaround time promotes reduced radiation exposure to occupational workers and improves cask utilization efficiency.

  1. Thermal-hydraulic analysis of spent fuel storage systems

    SciTech Connect

    Rector, D.R.; Wheeler, C.L.; Lombardo, N.J.

    1987-01-01

    This paper describes the COBRA-SFS (Spent Fuel Storage) computer code, which is designed to predict flow and temperature distributions in spent nuclear fuel storage and transportation systems. The decay heat generated by spent fuel in a dry storage cask is removed through a combination of conduction, natural convection, and thermal radiation. One major advantage of COBRA-SFS is that fluid recirculation within the cask is computed directly by solving the mass and momentum conservation equations. In addition, thermal radiation heat transfer is modeled using detailed radiation exchange factors based on quarter-rod segments. The equations governing mass, momentum, and energy conservation for incompressible flows are presented, and the semi-implicit solution method is described. COBRA-SFS predictions are compared to temperature data from a spent fuel storage cask test and the effect of different fill media on the cladding temperature distribution is discussed. The effect of spent fuel consolidation on cask thermal performance is also investigated. 16 refs., 6 figs., 2 tabs.

  2. COBRA-SFS. Thermal Hydraulic Analysis of Spent Fuel Casks

    SciTech Connect

    Michener, T.E.; Rector, D.R.; Cuta, J.M.; Enderlin, C.W.

    1995-09-01

    COBRA-SFS (Spent Fuel Storage) is a code for thermal-hydraulic analysis of multi-assembly spent fuel storage and transportation systems. It uses a lumped parameter finite difference approach to predict flow and temperature distributions in spent fuel storage systems and fuel assemblies, under forced and natural convection heat transfer conditions. Derived from the COBRA family of codes, which have been extensively evaluated against in-pile and out-of-pile data, COBRA-SFS retains all the important features of the COBRA codes for single phase fluid analysis, and extends the range application to include problems with two-dimensional radiative and three-dimensional conductive heat transfer. COBRA-SFS has been used to analyze various single- and multi-assembly spent fuel storage systems containing unconsolidated and consolidated fuel rods, with a variety of fill media, including air, helium and vacuum. Cycle 0 of COBRA-SFS was released in 1986. Subsequent applications of the code led to development of additional capabilities, which resulted in the release of Cycle 1 in February 1989. Since then, the code has undergone an independent technical review as part of a submittal to the Nuclear Regulatory Commission for a generic license to apply the code to spent fuel storage system analysis. Modifications and improvements to the code have been combined to form the latest release of the code, Cycle 2.

  3. Pyroprocess for processing spent nuclear fuel

    DOEpatents

    Miller, William E.; Tomczuk, Zygmunt

    2002-01-01

    This is a pyroprocess for processing spent nuclear fuel. The spent nuclear fuel is chopped into pieces and placed in a basket which is lowered in to a liquid salt solution. The salt is rich in ZrF.sub.4 and containing alkali or alkaline earth fluorides, and in particular, the salt chosen was LiF-50 mol % ZrF.sub.4 with a eutectic melting point of 500.degree. C. Prior to lowering the basket, the salt is heated to a temperature of between 550.degree. C. and 700.degree. C. in order to obtain a molten solution. After dissolution the oxides of U, Th, rare earth and other like oxides, the salt bath solution is subject to hydro-fluorination to remove the oxygen and then to a fluorination step to remove U as gaseous UF.sub.6. In addition, after dissolution, the basket contains PuO.sub.2 and undissolved parts of the fuel rods, and the basket and its contents are processed to remove the Pu.

  4. Impacts of warming and elevated CO2 on a semi-arid grassland are non-additive, shift with precipitation, and reverse over time.

    PubMed

    Mueller, K E; Blumenthal, D M; Pendall, E; Carrillo, Y; Dijkstra, F A; Williams, D G; Follett, R F; Morgan, J A

    2016-08-01

    It is unclear how elevated CO2 (eCO2 ) and the corresponding shifts in temperature and precipitation will interact to impact ecosystems over time. During a 7-year experiment in a semi-arid grassland, the response of plant biomass to eCO2 and warming was largely regulated by interannual precipitation, while the response of plant community composition was more sensitive to experiment duration. The combined effects of eCO2 and warming on aboveground plant biomass were less positive in 'wet' growing seasons, but total plant biomass was consistently stimulated by ~ 25% due to unique, supra-additive responses of roots. Independent of precipitation, the combined effects of eCO2 and warming on C3 graminoids became increasingly positive and supra-additive over time, reversing an initial shift toward C4 grasses. Soil resources also responded dynamically and non-additively to eCO2 and warming, shaping the plant responses. Our results suggest grasslands are poised for drastic changes in function and highlight the need for long-term, factorial experiments. PMID:27339693

  5. Metals removal from spent salts

    DOEpatents

    Hsu, Peter C.; Von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Brummond, William A.; Adamson, Martyn G.

    2002-01-01

    A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.

  6. Actinide removal from spent salts

    DOEpatents

    Hsu, Peter C.; von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Adamson, Martyn G.

    2002-01-01

    A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

  7. Biochar characteristics produced from malt spent rootlets

    NASA Astrophysics Data System (ADS)

    Fotopoulou, Kalliopi N.; Karapanagioti, Hrissi K.; Manariotis, Ioannis D.

    2013-04-01

    Biochar is a carbon-rich material produced by heating biomass in an oxygen-limited environment. Biochar is mainly used as an additive to soils to sequester carbon and improve soil fertility as well as a sorbent for environmental remediation processes. Surface properties such as point of zero charge, surface area and pore volume, surface topography, surface functional groups and acid-base behavior are important factors, which affect sorption efficiency. Understanding the surface alteration of biochars increases our understanding of the pollutant-sorbent interaction. Malt spent rootlets (MSR) is a by-product formed during beer production, is inexpensive and is produced in high quantities. The objective of the present study was to characterize the surface properties of biochar produced from MSR, and to investigate the effect of thermal treatment conditions on key characteristics that affect sorptive properties. The surface area, the pore volume, and the average pore size of the biochars were determined using gas (N2) adsorption-desorption cycles using the Brunauer, Emmett, and Teller (BET) equation. Isotherms with 30 adsorption and 20 desorption points were conducted at liquid nitrogen temperature (77K). Open surface area and micropore volume were determined using t-plot method and Harkins & Jura equation. Total organic carbon was also determined because it is an important factor that affects sorption. Raw MSR demonstrates low surface area that increases by 1 order of magnitude by thermal treatment up to 750oC. At temperatures from 750 up to 900oC, pyrolysis results to biochars with surface areas 210-340 m2/g. For the same temperature range, a high percentage (46-73%) of the pore volume of the biochars is due to micropores. Similar results were observed for all the grain size fractions of the raw MSR. The up-scaling of the biochar production was easily performed by using increased biomass analogous to the bigger vessels used each time. Positive results were obtained

  8. Spent fuel integrity during transportation

    SciTech Connect

    Funk, C.W.; Jacobson, L.D.

    1980-01-01

    The conditions of recent shipments of light water reactor spent fuel were surveyed. The radioactivity level of cask coolant was examined in an attempt to find the effects of transportation on LWR fuel assemblies. Discussion included potential cladding integrity loss mechanisms, canning requirements, changes of radioactivity levels, and comparison of transportation in wet or dry media. Although integrity loss or degradation has not been identified, radioactivity levels usually increase during transportation, especially for leaking assemblies.

  9. Spent fuel shipping cask handling capability assessment of 27 selected light water reactors

    SciTech Connect

    Konzek, G.J.; Daling, P.M.

    1984-11-01

    This report presents an assessment of the spent fuel shipping cask handling capabilities of those nuclear plants currently projected to lose full core reserve capability in their spent fuel storage basins in the near future. The purpose of this assessment is to determine which cask types, in the current fleet, each of the selected reactors can handle. The cask handling capability of a nuclear plant depends upon both external and internal conditions at the plant. The availability of a rail spur, the lifting capacity of the crane, the adequacy of clearances in the cask receiving, loading, and decontamination areas and similar factors can limit the types of casks that can be utilized at a particular plant. This report addresses the major facility capabilities used in assessing the types of spent fuel shipping casks that can be handled at each of the 27 selected nuclear plants approaching a critical storage situation. The results of this study cannot be considered to be final and are not intended to be used to force utilities to ship by a particular mode. In addition, many utilities have never shipped spent fuel. Readers are cautioned that the results of this study reflect the current situation at the selected plants and are based on operator perceptions and guidance from NRC related to the control of heavy loads at nuclear power plants. Thus, the cask handling capabilities essentially represent snap-shots in time and could be subject to change as plants further analyze their capabilities, even in the near-term. The results of this assessment indicate that 48% of the selected plants have rail access and 59% are judged to be candidates for overweight truck shipments (with 8 unknowns due to unavailability of verifiable data). Essentially all of the reactors can accommodate existing legal-weight truck casks. 12 references, 1 figure, 4 tables.

  10. HTGR Spent Fuel Treatment Program. HTGR Spent Fuel Treatment Development Program Plan

    SciTech Connect

    Not Available

    1984-12-01

    The spent fuel treatment (SFT) program plan addresses spent fuel volume reduction, packaging, storage, transportation, fuel recovery, and disposal to meet the needs of the HTGR Lead Plant and follow-on plants. In the near term, fuel refabrication will be addressed by following developments in fresh fuel fabrication and will be developed in the long term as decisions on the alternatives dictate. The formulation of this revised program plan considered the implications of the Nuclear Waste Policy Act of 1982 (NWPA) which, for the first time, established a definitive national policy for management and disposal of nuclear wastes. Although the primary intent of the program is to address technical issues, the divergence between commercial and government interests, which arises as a result of certain provisions of the NWPA, must be addressed in the economic assessment of technically feasible alternative paths in the management of spent HTGR fuel and waste. This new SFT program plan also incorporates a significant cooperative research and development program between the United States and the Federal Republic of Germany. The major objective of this international program is to reduce costs by avoiding duplicate efforts.

  11. Criticality of spent reactor fuel

    SciTech Connect

    Harris, D.R.

    1987-01-01

    The storage capacity of spent reactor fuel pools can be greatly increased by consolidation. In this process, the fuel rods are removed from reactor fuel assemblies and are stored in close-packed arrays in a canister or skeleton. An earlier study examined criticality consideration for consolidation of Westinghouse fuel, assumed to be fresh, in canisters at the Millstone-2 spent-fuel pool and in the General Electric IF-300 shipping cask. The conclusions were that the fuel rods in the canister are so deficient in water that they are adequately subcritical, both in normal and in off-normal conditions. One potential accident, the water spill event, remained unresolved in the earlier study. A methodology is developed here for spent-fuel criticality and is applied to the water spill event. The methodology utilizes LEOPARD to compute few-group cross sections for the diffusion code PDQ7, which then is used to compute reactivity. These codes give results for fresh fuel that are in good agreement with KENO IV-NITAWL Monte Carlo results, which themselves are in good agreement with continuous energy Monte Carlo calculations. These methodologies are in reasonable agreement with critical measurements for undepleted fuel.

  12. Stochastic sampled-data control for synchronization of complex dynamical networks with control packet loss and additive time-varying delays.

    PubMed

    Rakkiyappan, R; Sakthivel, N; Cao, Jinde

    2015-06-01

    This study examines the exponential synchronization of complex dynamical networks with control packet loss and additive time-varying delays. Additionally, sampled-data controller with time-varying sampling period is considered and is assumed to switch between m different values in a random way with given probability. Then, a novel Lyapunov-Krasovskii functional (LKF) with triple integral terms is constructed and by using Jensen's inequality and reciprocally convex approach, sufficient conditions under which the dynamical network is exponentially mean-square stable are derived. When applying Jensen's inequality to partition double integral terms in the derivation of linear matrix inequality (LMI) conditions, a new kind of linear combination of positive functions weighted by the inverses of squared convex parameters appears. In order to handle such a combination, an effective method is introduced by extending the lower bound lemma. To design the sampled-data controller, the synchronization error system is represented as a switched system. Based on the derived LMI conditions and average dwell-time method, sufficient conditions for the synchronization of switched error system are derived in terms of LMIs. Finally, numerical example is employed to show the effectiveness of the proposed methods. PMID:25797504

  13. DOE SPENT NUCLEAR FUEL DISPOSAL CONTAINER

    SciTech Connect

    F. Habashi

    1998-06-26

    The DOE Spent Nuclear Fuel Disposal Container (SNF DC) supports the confinement and isolation of waste within the Engineered Barrier System of the Mined Geologic Disposal System (MGDS). Disposal containers are loaded and sealed in the surface waste handling facilities, transferred to the underground through the access mains, and emplaced in emplacement drifts. The DOE Spent Nuclear Fuel Disposal Container provides long term confinement of DOE SNF waste, and withstands the loading, transfer, emplacement, and retrieval loads and environments. The DOE SNF Disposal Containers provide containment of waste for a designated period of time, and limit radionuclide release thereafter. The disposal containers maintain the waste in a designated configuration, withstand maximum handling and rockfall loads, limit the individual waste canister temperatures after emplacement. The disposal containers also limit the introduction of moderator into the disposal container during the criticality control period, resist corrosion in the expected repository environment, and provide complete or limited containment of waste in the event of an accident. Multiple disposal container designs may be needed to accommodate the expected range of DOE Spent Nuclear Fuel. The disposal container will include outer and inner barrier walls and outer and inner barrier lids. Exterior labels will identify the disposal container and contents. Differing metal barriers will support the design philosophy of defense in depth. The use of materials with different failure mechanisms prevents a single mode failure from breaching the waste package. The corrosion-resistant inner barrier and inner barrier lid will be constructed of a high-nickel alloy and the corrosion-allowance outer barrier and outer barrier lid will be made of carbon steel. The DOE Spent Nuclear Fuel Disposal Containers interface with the emplacement drift environment by transferring heat from the waste to the external environment and by protecting

  14. Effect of spent craft brewers’ yeast on fermentation and methane production by rumen microorganisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saccharomyces cerevisiae is a key component of beer brewing and a major by-product. The leftover, spent brewers’ yeast, from large breweries has been used for some time as a protein supplement in cattle, however the possible advantages of spent yeast from smaller craft breweries, containing much hig...

  15. Separation of actinides from spent nuclear fuel: A review.

    PubMed

    Veliscek-Carolan, Jessica

    2016-11-15

    This review summarises the methods currently available to extract radioactive actinide elements from solutions of spent nuclear fuel. This separation of actinides reduces the hazards associated with spent nuclear fuel, such as its radiotoxicity, volume and the amount of time required for its' radioactivity to return to naturally occurring levels. Separation of actinides from environmental water systems is also briefly discussed. The actinide elements typically found in spent nuclear fuel include uranium, plutonium and the minor actinides (americium, neptunium and curium). Separation methods for uranium and plutonium are reasonably well established. On the other hand separation of the minor actinides from lanthanide fission products also present in spent nuclear fuel is an ongoing challenge and an area of active research. Several separation methods for selective removal of these actinides from spent nuclear fuel will be described. These separation methods include solvent extraction, which is the most commonly used method for radiochemical separations, as well as the less developed but promising use of adsorption and ion-exchange materials. PMID:27427893

  16. Foreign experience in extended dry storage of spent nuclear fuel

    SciTech Connect

    Schneider, K.J.; Mitchell, S.J.

    1992-06-01

    Most countries with nuclear power are planning for spent nuclear fuel (or high-level waste from reprocessing of spent fuel) to be disposed of in national deep geological repositories starting in the time period of about 2010 to 2050. While spent fuel has been stored in water basins for the early years after discharge from the reactors, interim dry storage for extended periods (i.e., several tens of years) is being implemented or considered in an increasing number of countries. Dry storage technology is generally considered to be developed on a world-wide basis, and is being initiated and/ or expanded in a number of countries. This paper presents a summary of status and experience in dry storage of spent fuel in other countries, with emphasis on zirconium-clad fuels. Past activities, current status, future plans, research and development, and experience in dry storage are summarized for Argentina, Canada, France, former West Germany, former East Germany, India, Italy, Japan, South Korea, Spain, Switzerland, United Kingdom, and the former Soviet Union. Conclusions from their experience are presented. Their experience to date supports the expectations that proper dry storage should provide for safe extended dry storage of spent fuel.

  17. Automated Characterization of Spent Fuel through the Multi-Isotope Process (MIP) Monitor

    SciTech Connect

    Coble, Jamie B.; Orton, Christopher R.; Schwantes, Jon M.

    2012-07-31

    This research developed an algorithm for characterizing spent nuclear fuel (SNF) samples based on simulated gamma spectra. The gamma spectra for a variety of light water reactor fuels typical of those found in the United States were simulated. Fuel nuclide concentrations were simulated in ORIGEN-ARP for 1296 fuel samples with a variety of reactor designs, initial enrichments, burn ups, and cooling times. The results of the ORIGEN-ARP simulation were then input to SYNTH to simulate the gamma spectrum for each sample. These spectra were evaluated with partial least squares (PLS)-based multivariate analysis methods to characterize the fuel according to reactor type (pressurized or boiling water reactor), enrichment, burn up, and cooling time. Characterizing some of the features in series by using previously estimated features in the prediction greatly improves the performance. By first classifying the spent fuel reactor type and then using type-specific models, the prediction error for enrichment, burn up, and cooling time improved by a factor of two to four. For some features, the prediction was further improved by including additional information, such as including the predicted burn up in the estimation of cooling time. The optimal prediction flow was determined based on the simulated data. A PLS discriminate analysis model was developed which perfectly classified SNF reactor type. Burn up was predicted within 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment within approximately 2% RMSPE.

  18. Food additives

    MedlinePlus

    Food additives are substances that become part of a food product when they are added during the processing or making of that food. "Direct" food additives are often added during processing to: Add nutrients ...

  19. Treatment of spent NTA-based decontamination solutions

    NASA Astrophysics Data System (ADS)

    Pavlík, A.; Semelová, M.; John, J.; Černochová, K.; Šebesta, F.

    2006-01-01

    This study deals with potential treatment of spent NTA-containing decontamination solutions for final disposal. The method proposed is based on the degradation of organic substances followed by the separation of radionuclides. The influence of various parameters (pH value, irradiation time, temperature, catalyst amount, type and various combinations of catalysts) on photocatalytic degradation of NTA has been studied. Photo-Fenton reagent (Fe3+/H2O2) as a homogenous catalyst was found to be much more efficient than the TiO2-based heterogeneous catalyst Degussa P25. Under optimum conditions NTA in a simulant of a spent decontamination solution without or with hydrazine could be degraded within 5 or 9 hours, respectively. The study of sorption properties of a series of absorbers revealed that radiostrontium and radiosilver can be effectively removed from the simulant of a spent decontamination solution even in the presence of NTA, while total NTA degradation is necessary for effective radiocobalt separation.

  20. Computer simulation for the growing probability of additional offspring with an advantageous reversal allele in the decoupled continuous-time mutation-selection model

    NASA Astrophysics Data System (ADS)

    Gill, Wonpyong

    2016-01-01

    This study calculated the growing probability of additional offspring with the advantageous reversal allele in an asymmetric sharply-peaked landscape using the decoupled continuous-time mutation-selection model. The growing probability was calculated for various population sizes, N, sequence lengths, L, selective advantages, s, fitness parameters, k and measuring parameters, C. The saturated growing probability in the stochastic region was approximately the effective selective advantage, s*, when C≫1/Ns* and s*≪1. The present study suggests that the growing probability in the stochastic region in the decoupled continuous-time mutation-selection model can be described using the theoretical formula for the growing probability in the Moran two-allele model. The selective advantage ratio, which represents the ratio of the effective selective advantage to the selective advantage, does not depend on the population size, selective advantage, measuring parameter and fitness parameter; instead the selective advantage ratio decreases with the increasing sequence length.

  1. Spent nuclear fuel project design basis capacity study

    SciTech Connect

    Cleveland, K.J.

    1996-09-09

    A parametric study of the Spent Nuclear Fuel Project system capacity is presented. The study was completed using a commercially available software package to develop a summary level model of the major project systems. Alternative configurations, sub-system cycle times, and operating scenarios were tested to identify their impact on total project duration and equipment requirements.

  2. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  3. Reactor-specific spent fuel discharge projections, 1984 to 2020

    SciTech Connect

    Heeb, C.M.; Libby, R.A.; Holter, G.M.

    1985-04-01

    The original spent fuel utility data base (SFDB) has been adjusted to produce agreement with the EIA nuclear energy generation forecast. The procedure developed allows the detail of the utility data base to remain intact, while the overall nuclear generation is changed to match any uniform nuclear generation forecast. This procedure adjusts the weight of the reactor discharges as reported on the SFDB and makes a minimal (less than 10%) change in the original discharge exposures in order to preserve discharges of an integral number of fuel assemblies. The procedure used in developing the reactor-specific spent fuel discharge projections, as well as the resulting data bases themselves, are described in detail in this report. Discussions of the procedure cover the following topics: a description of the data base; data base adjustment procedures; addition of generic power reactors; and accuracy of the data base adjustments. Reactor-specific discharge and storage requirements are presented. Annual and cumulative discharge projections are provided. Annual and cumulative requirements for additional storage are shown for the maximum at-reactor (AR) storage assumption, and for the maximum AR with transshipment assumption. These compare directly to the storage requirements from the utility-supplied data, as reported in the Spent Fuel Storage Requirements Report. The results presented in this report include: the disaggregated spent fuel discharge projections; and disaggregated projections of requirements for additional spent fuel storage capacity prior to 1998. Descriptions of the methodology and the results are included in this report. Details supporting the discussions in the main body of the report, including descriptions of the capacity and fuel discharge projections, are included. 3 refs., 6 figs., 12 tabs.

  4. Health and safety impacts related to the management of spent nuclear fuels

    SciTech Connect

    Jilek, D.C.

    1996-06-01

    Under the Nuclear Waste Policy Act of 1982, as amended, the U.S. Department of Energy is responsible for managing the disposal of spent nuclear fuel from civilian nuclear power plants. Deployment of a multipurpose canister (MPC) system for dry storage of commercial spent nuclear fuel at reactor sites was determined to be an option for managing spent nuclear fuel until either a permanent repository or interim central storage facility (commonly called a Monitored Retrievable Storage Facility, or MRS) becomes available. Routine health and safety impacts to workers from handling and storage operations at nuclear facilities for four separate scenarios were evaluated for the MPC system: an on-time repository with an MRS; an on-time repository with no MRS; a delayed repository with an MRS; and a delayed repository with no MRS. In addition to evaluating the MPC system, five alternatives were analyzed. These included the No Action Alternative (NAA), Current Technology (CTr), the Transposable Storage Cask (TSC), the Dual-Purpose Canister (DPC), and the Small MPC (SmMPC). Health effects are expressed as collective doses in person- rem per year and risks as latent cancer fatalities per year for incident-free operations for each alternative and scenario. Results show that both dose and risks to workers vary as much as 68{percent} among scenarios and alternatives. Although dose estimates and risks fall below limits for radiation dose to workers as specified in Title 10, Part 20, of the Code of Federal Regulations, additional measures could be applied to reduce potential doses and resultant health risk. 5 refs., 2 tabs.

  5. Recovery of zinc and manganese from spent batteries by reductive leaching in acidic media

    NASA Astrophysics Data System (ADS)

    Buzatu, M.; Săceanu, S.; Petrescu, M. I.; Ghica, G. V.; Buzatu, T.

    2014-02-01

    A systematic investigation has been carried out on the influence of the acid leaching process parameters on the simultaneous metal recovery (Zn and Mn) from the electrode paste of spent alkaline Zn-MnO2 and spent Zn-C batteries. By introducing a reducing agent namely 30% H2O2 in the H2SO4 leaching solution the extraction efficiency for Mn was increased from 43.5% (no addition of H2O2) up to 97.54% (50% excess H2O2 in comparison with the required stoichiometric amount of H2O2). This H2O2 addition proved to have no influence on Zn extraction efficiency which kept constant at a high level (∼98.4%). A less important influence has been noticed for the molar concentration of H2SO4 in the leaching solution. In the range 0.5 M up to 2 M molar concentration of H2SO4 the extraction efficiency was increased from 78.2% up to 98.4% for Zn and from 63.1% up to 97.2% for Mn. Leaching time up to 60 min proved to gradually increase the extraction efficiency up to 96% for Mn and 98% for Zn but further time increase has no more influence. An attempt has been made to recover the carbon from the leaching residue but its structural characterization is still required.

  6. Spent nuclear fuel sampling strategy

    SciTech Connect

    Bergmann, D.W.

    1995-02-08

    This report proposes a strategy for sampling the spent nuclear fuel (SNF) stored in the 105-K Basins (105-K East and 105-K West). This strategy will support decisions concerning the path forward SNF disposition efforts in the following areas: (1) SNF isolation activities such as repackaging/overpacking to a newly constructed staging facility; (2) conditioning processes for fuel stabilization; and (3) interim storage options. This strategy was developed without following the Data Quality Objective (DQO) methodology. It is, however, intended to augment the SNF project DQOS. The SNF sampling is derived by evaluating the current storage condition of the SNF and the factors that effected SNF corrosion/degradation.

  7. Chemical speciation of neptunium in spent fuel. Annual report for period 15 August 1999 to 15 August 2000

    SciTech Connect

    Ken Czerwinski; Don Reed

    2000-09-01

    (B204) This project will examine the chemical speciation of neptunium in spent nuclear fuel. The R&D fields covered by the project include waste host materials and actinide chemistry. Examination of neptunium is chosen since it was identified as a radionuclide of concern by the NERI workshop. Additionally, information on the chemical form of neptunium in spent fuel is lacking. The identification of the neptunium species in spent fuel would allow a greater scientific based understanding of its long-term fate and behavior in waste forms. Research to establish the application and development of X-ray synchrotrons radiation (XSR) techniques to determine the structure of aqueous, adsorbed, and solid actinide species of importance to nuclear considerations is being conducted at Argonne. These studies extend current efforts within the Chemical Technology Division at Argonne National Laboratory to investigate actinide speciation with more conventional spectroscopic and solids characterization (e.g. SEM, TEM, and XRD) methods. Our project will utilize all these techniques for determining neptunium speciation in spent fuel. We intend to determine the chemical species and oxidation state of neptunium in spent fuel and alteration phases. Different types of spent fuel will be examined. Once characterized, the chemical behavior of the identified neptunium species will be evaluated if it is not present in the literature. Special attention will be given to the behavior of the neptunium species under typical repository near-field conditions (elevated temperature, high pH, varying Eh). This will permit a timely inclusion of project results into near-field geochemical models. Additionally, project results and methodologies have applications to neptunium in the environment, or treatment of neptunium containing waste. Another important aspect of this project is the close cooperation between a university and a national laboratory. The PI has a transuranic laboratory at MIT where

  8. Systems for the Intermodal Routing of Spent Nuclear Fuel

    SciTech Connect

    Peterson, Steven K; Liu, Cheng

    2015-01-01

    The safe and secure movement of spent nuclear fuel from shutdown and active reactor facilities to intermediate or long term storage sites may, in some instances, require the use of several modes of transportation to accomplish the move. To that end, a fully operable multi-modal routing system is being developed within Oak Ridge National Laboratory s (ORNL) WebTRAGIS (Transportation Routing Analysis Geographic Information System). This study aims to provide an overview of multi-modal routing, the existing state of the TRAGIS networks, the source data needs, and the requirements for developing structural relationships between various modes to create a suitable system for modeling the transport of spent nuclear fuel via a multimodal network. Modern transportation systems are comprised of interconnected, yet separate, modal networks. Efficient transportation networks rely upon the smooth transfer of cargoes at junction points that serve as connectors between modes. A key logistical impediment to the shipment of spent nuclear fuel is the absence of identified or designated transfer locations between transport modes. Understanding the potential network impacts on intermodal transportation of spent nuclear fuel is vital for planning transportation routes from origin to destination. By identifying key locations where modes intersect, routing decisions can be made to prioritize cost savings, optimize transport times and minimize potential risks to the population and environment. In order to facilitate such a process, ORNL began the development of a base intermodal network and associated routing code. The network was developed using previous intermodal networks and information from publicly available data sources to construct a database of potential intermodal transfer locations with likely capability to handle spent nuclear fuel casks. The coding development focused on modifying the existing WebTRAGIS routing code to accommodate intermodal transfers and the selection of

  9. Transportation accident scenarios for commercial spent fuel

    SciTech Connect

    Wilmot, E L

    1981-02-01

    A spectrum of high severity, low probability, transportation accident scenarios involving commercial spent fuel is presented together with mechanisms, pathways and quantities of material that might be released from spent fuel to the environment. These scenarios are based on conclusions from a workshop, conducted in May 1980 to discuss transportation accident scenarios, in which a group of experts reviewed and critiqued available literature relating to spent fuel behavior and cask response in accidents.

  10. Storage assembly for spent nuclear fuel

    SciTech Connect

    Lapides, M.E.

    1982-04-27

    A technique for storing spent fuel rods from a nuclear reactor is disclosed herein. This technique utilizes a housing including a closed inner chamber for containing the fuel rods and a thermally conductive member located partially within the housing chamber and partially outside the housing for transferring heat generated by the fuel rods from the chamber to the ambient surroundings. Particulate material is located within the chamber and surrounds the fuel rods contained therein. This material is selected to serve as a heat transfer media between the contained cells and the heat transferring member and, at the same time, stand ready to fuse into a solid mass around the contained cells if the heat transferring member malfunctions or otherwise fails to transfer the generated heat out of the housing chamber in a predetermined way.

  11. Characterization plan for Hanford spent nuclear fuel

    SciTech Connect

    Abrefah, J.; Thornton, T.A.; Thomas, L.E.; Berting, F.M.; Marschman, S.C.

    1994-12-01

    Reprocessing of spent nuclear fuel (SNF) at the Hanford Site Plutonium-Uranium Extraction Plant (PUREX) was terminated in 1972. Since that time a significant quantity of N Reactor and Single-Pass Reactor SNF has been stored in the 100 Area K-East (KE) and K-West (KW) reactor basins. Approximately 80% of all US Department of Energy (DOE)-owned SNF resides at Hanford, the largest portion of which is in the water-filled KE and KW reactor basins. The basins were not designed for long-term storage of the SNF and it has become a priority to move the SNF to a more suitable location. As part of the project plan, SNF inventories will be chemically and physically characterized to provide information that will be used to resolve safety and technical issues for development of an environmentally benign and efficient extended interim storage and final disposition strategy for this defense production-reactor SNF.

  12. Cellulase Production from Spent Lignocellulose Hydrolysates by Recombinant Aspergillus niger▿

    PubMed Central

    Alriksson, Björn; Rose, Shaunita H.; van Zyl, Willem H.; Sjöde, Anders; Nilvebrant, Nils-Olof; Jönsson, Leif J.

    2009-01-01

    A recombinant Aspergillus niger strain expressing the Hypocrea jecorina endoglucanase Cel7B was grown on spent hydrolysates (stillage) from sugarcane bagasse and spruce wood. The spent hydrolysates served as excellent growth media for the Cel7B-producing strain, A. niger D15[egI], which displayed higher endoglucanase activities in the spent hydrolysates than in standard medium with a comparable monosaccharide content (e.g., 2,100 nkat/ml in spent bagasse hydrolysate compared to 480 nkat/ml in standard glucose-based medium). In addition, A. niger D15[egI] was also able to consume or convert other lignocellulose-derived compounds, such as acetic acid, furan aldehydes, and phenolic compounds, which are recognized as inhibitors of yeast during ethanolic fermentation. The results indicate that enzymes can be produced from the stillage stream as a high-value coproduct in second-generation bioethanol plants in a way that also facilitates recirculation of process water. PMID:19251882

  13. Effect of addition of lycopene to calcium hydroxide and chlorhexidine as intracanal medicament on fracture resistance of radicular dentin at two different time intervals: An in vitro study

    PubMed Central

    Madhusudhana, Koppolu; Archanagupta, Kasamsetty; Suneelkumar, Chinni; Lavanya, Anumula; Deepthi, Mandava

    2015-01-01

    Background: Long-term use of intracanal medicaments such as calcium hydroxide (CH) reduces the fracture resistance of dentin. The present study was undertaken to evaluate the fracture resistance of radicular dentin on long-term use of CH, chlorhexidine (CHX) with lycopene (LP). Aim: To compare the fracture resistance of radicular dentin when intracanal medicaments such as CH, CHX with LP were used for 1-week and 1-month time interval. Settings and Design: Sixty single-rooted extracted human permanent premolars were collected, and complete instrumentation was done. Samples were divided into three groups based on intracanal medicament used. Materials and Methods: Group 1 - no medicament was placed (CON), group 2 - mixture of 1.5 g of CH and 1 ml of 2% CHX (CHCHX), group 3 - mixture of 1.5 g of CH, 1 ml of CHX and 1 ml of 5% LP solution (CHCHXLP). After storage period of each group for 1-week and 1-month, middle 8 mm root cylinder was sectioned and tested for fracture resistance. Statistical Analysis: Results were analyzed using paired t-test. Results: At 1-month time interval, there was a statistically significant difference in fracture resistance between CHCHX and CHCHXLP groups. Conclusion: Addition of LP has not decreased the fracture resistance of radicular dentin after 1-month. PMID:26069405

  14. Task Time Tracker

    2013-07-24

    This client-side web app tracks the amount of time spent on arbitrary tasks. It allosw the creation of an unlimited number of arbitrarily named tasks ans via simple interactions, tracks the amount of time spent working on the drfined tasks.

  15. Food additives.

    PubMed

    Berglund, F

    1978-01-01

    The use of additives to food fulfils many purposes, as shown by the index issued by the Codex Committee on Food Additives: Acids, bases and salts; Preservatives, Antioxidants and antioxidant synergists; Anticaking agents; Colours; Emulfifiers; Thickening agents; Flour-treatment agents; Extraction solvents; Carrier solvents; Flavours (synthetic); Flavour enhancers; Non-nutritive sweeteners; Processing aids; Enzyme preparations. Many additives occur naturally in foods, but this does not exclude toxicity at higher levels. Some food additives are nutrients, or even essential nutritents, e.g. NaCl. Examples are known of food additives causing toxicity in man even when used according to regulations, e.g. cobalt in beer. In other instances, poisoning has been due to carry-over, e.g. by nitrate in cheese whey - when used for artificial feed for infants. Poisonings also occur as the result of the permitted substance being added at too high levels, by accident or carelessness, e.g. nitrite in fish. Finally, there are examples of hypersensitivity to food additives, e.g. to tartrazine and other food colours. The toxicological evaluation, based on animal feeding studies, may be complicated by impurities, e.g. orthotoluene-sulfonamide in saccharin; by transformation or disappearance of the additive in food processing in storage, e.g. bisulfite in raisins; by reaction products with food constituents, e.g. formation of ethylurethane from diethyl pyrocarbonate; by metabolic transformation products, e.g. formation in the gut of cyclohexylamine from cyclamate. Metabolic end products may differ in experimental animals and in man: guanylic acid and inosinic acid are metabolized to allantoin in the rat but to uric acid in man. The magnitude of the safety margin in man of the Acceptable Daily Intake (ADI) is not identical to the "safety factor" used when calculating the ADI. The symptoms of Chinese Restaurant Syndrome, although not hazardous, furthermore illustrate that the whole ADI

  16. Transport and leaching of technetium and uranium from spent UO 2 fuel in compacted bentonite clay

    NASA Astrophysics Data System (ADS)

    Ramebäck, H.; Albinsson, Y.; Skålberg, M.; Eklund, U. B.; Kjellberg, L.; Werme, L.

    2000-01-01

    The transport properties of Tc and U in compacted bentonite clay and the leaching behaviour of these elements from spent nuclear fuel in the same system were investigated. Pieces of spent UO 2 fuel were embedded in bentonite clay ( ρ d=2100 kg/m 3). A low saline synthetic groundwater was used as the aqueous phase. After certain experimental times, the bentonite clay was cut into 0.1 mm thick slices, which were analysed for their content of Tc and U. Measurements were made using inductively coupled plasma mass spectrometry. Tc analysis comprised chemical separation. The analysis of U was done by means of detecting 236U, since the natural content of U in bentonite clay made it impossible to distinguish between U originating from the fuel and the clay. The influence of different additives mixed into the clay was studied. The results showed an influence on both transport and leaching behaviour when metallic Fe was mixed into the clay. This indicates that Tc and U are reduced to their lower oxidation states as a result of this additive.

  17. Spent Nuclear Fuel (SNF) Project Execution Plan

    SciTech Connect

    LEROY, P.G.

    2000-11-03

    The Spent Nuclear Fuel (SNF) Project supports the Hanford Site Mission to cleanup the Site by providing safe, economic, environmentally sound management of Site spent nuclear fuel in a manner that reduces hazards by staging it to interim onsite storage and deactivates the 100 K Area facilities.

  18. Spent Fuel Test - Climax data acquisition system operations manual

    SciTech Connect

    Nyholm, R.A.

    1983-01-01

    The Spent Fuel Test-Climax (SFT-C) is a test of the retrievable, deep geologic storage of commercially generated, spent nuclear reactor fuel in granite rock. Eleven spent fuel assemblies, together with 6 electrical simulators and 20 guard heaters, are emplaced 420 m below the surface in the Climax granite at the US Department of Energy Nevada Test Site. On June 2, 1978, Lawrence Livermore National Laboratory (LLNL) secured funding for the SFT-C, and completed spent fuel emplacement May 28, 1980. The multi-year duration test is located in a remote area and is unattended much of the time. An extensive array of radiological safety and geotechnical instrumentation is deployed to monitor the test performance. A dual minicomputer-based data acquisition system (DAS) collects and processes data from more than 900 analog instruments. This report documents the software element of the LLNL developed SFT-C Data Acquisition System. It defines the operating system and hardware interface configurations, the special applications software and data structures, and support software.

  19. Spent fuel test. Climax data acquisition system integration report

    SciTech Connect

    Nyholm, R.A.; Brough, W.G.; Rector, N.L.

    1982-06-01

    The Spent Fuel Test - Climax (SFT-C) is a test of the retrievable, deep geologic storage of commercially generated, spent nuclear reactor fuel in granitic rock. Eleven spent fuel assemblies, together with 6 electrical simulators and 20 guard heaters, are emplaced 420 m below the surface in the Climax granite at the Nevada Test Site. On June 2, 1978, Lawrence Livermore National Laboratory (LLNL) secured funding for the SFT-C, and completed spent fuel emplacement May 28, 1980. This multi-year duration test is located in a remote area and is unattended much of the time. An extensive array of radiological safety and geotechnical instrumentation is deployed to monitor the test performance. A dual minicomputer-based data acquisition system collects and processes data from more than 900 analog instruments. This report documents the design and functions of the hardware and software elements of the Data Acquisition System and describes the supporting facilities which include environmental enclosures, heating/air-conditioning/humidity systems, power distribution systems, fire suppression systems, remote terminal stations, telephone/modem communications, and workshop areas. 9 figures.

  20. Nuclear mass inventory, photon dose rate and thermal decay heat of spent research reactor fuel assemblies

    SciTech Connect

    Pond, R.B.; Matos, J.E.

    1996-12-31

    This document has been prepared to assist research reactor operators possessing spent fuel containing enriched uranium of United States origin to prepare part of the documentation necessary to ship this fuel to the United States. Data are included on the nuclear mass inventory, photon dose rate, and thermal decay heat of spent research reactor fuel assemblies. Isotopic masses of U, Np, Pu and Am that are present in spent research reactor fuel are estimated for MTR, TRIGA and DIDO-type fuel assembly types. The isotopic masses of each fuel assembly type are given as functions of U-235 burnup in the spent fuel, and of initial U-235 enrichment and U-235 mass in the fuel assembly. Photon dose rates of spent MTR, TRIGA and DIDO-type fuel assemblies are estimated for fuel assemblies with up to 80% U-235 burnup and specific power densities between 0.089 and 2.857 MW/kg[sup 235]U, and for fission product decay times of up to 20 years. Thermal decay heat loads are estimated for spent fuel based upon the fuel assembly irradiation history (average assembly power vs. elapsed time) and the spent fuel cooling time.

  1. A Monte Carlo based spent fuel analysis safeguards strategy assessment

    SciTech Connect

    Fensin, Michael L; Tobin, Stephen J; Swinhoe, Martyn T; Menlove, Howard O; Sandoval, Nathan P

    2009-01-01

    Safeguarding nuclear material involves the detection of diversions of significant quantities of nuclear materials, and the deterrence of such diversions by the risk of early detection. There are a variety of motivations for quantifying plutonium in spent fuel assemblies by means of nondestructive assay (NDA) including the following: strengthening the capabilities of the International Atomic Energy Agencies ability to safeguards nuclear facilities, shipper/receiver difference, input accountability at reprocessing facilities and burnup credit at repositories. Many NDA techniques exist for measuring signatures from spent fuel; however, no single NDA technique can, in isolation, quantify elemental plutonium and other actinides of interest in spent fuel. A study has been undertaken to determine the best integrated combination of cost effective techniques for quantifying plutonium mass in spent fuel for nuclear safeguards. A standardized assessment process was developed to compare the effective merits and faults of 12 different detection techniques in order to integrate a few techniques and to down-select among the techniques in preparation for experiments. The process involves generating a basis burnup/enrichment/cooling time dependent spent fuel assembly library, creating diversion scenarios, developing detector models and quantifying the capability of each NDA technique. Because hundreds of input and output files must be managed in the couplings of data transitions for the different facets of the assessment process, a graphical user interface (GUI) was development that automates the process. This GUI allows users to visually create diversion scenarios with varied replacement materials, and generate a MCNPX fixed source detector assessment input file. The end result of the assembly library assessment is to select a set of common source terms and diversion scenarios for quantifying the capability of each of the 12 NDA techniques. We present here the generalized

  2. Regulation of spent nuclear fuel shipment: A state perspective

    SciTech Connect

    Halstead, R.J.; Sinderbrand, C.; Woodbury, D.

    1987-01-01

    In 1985, the Wisconsin Department of Natural Resources (WDNR) sought to regulate rail shipments of spent nuclear fuel through the state, because federal regulations did not adequately protect the environmentally sensitive corridor along the route of the shipments. A state interagency working group identified five serious deficiencies in overall federal regulatory scheme: 1) failure to consider the safety or environmental risks associated with selected routes; 2) abscence of route-specific emergency response planning; 3) failure of the NRC to regulate the carrier of spent nuclear fuel or consider its safety record; 4) abscence of requirements for determination of need for, or the propriety of, specific shipments of spent nuclear fuel; and 5) the lack of any opportunity for meaningful public participation with respect to the decision to transport spent nuclear fuel. Pursuant to Wisconsin's hazardous substance statutes, the WDNR issues an order requiring the utility to file a spill prevention and mitigation plan or cease shipping through Wisconsin. A state trial court judge upheld the utility's challenge to Wisconsin's spill plan requirements, based on federal preemption of state authority. The state is now proposing federal legislation which would require: 1) NRC determination of need prior to approval of offsite shipment of spent fuel by the licensees; 2) NRC assessment of the potential environmental impacts of shipments along the proposed route, and comparative evaluation of alternative modes and routes; and 3) NRC approval of a route-specific emergency response and mitigation plan, including local training and periodic exercises. Additionally, the proposed legislation would authorize States and Indian Tribes to establish regulatory programs providing for permits, inspection, contingency plans for monitoring, containments, cleanup and decontamination, surveillance, enforcement and reasonable fees. 15 refs.

  3. Green technology effect of injection pressure, timing and compression ratio in constant pressure heat addition cycle by an eco-friendly material.

    PubMed

    Karthikayan, S; Sankaranarayanan, G; Karthikeyan, R

    2015-11-01

    Present energy strategies focus on environmental issues, especially environmental pollution prevention and control by eco-friendly green technologies. This includes, increase in the energy supplies, encouraging cleaner and more efficient energy management, addressing air pollution, greenhouse effect, global warming, and climate change. Biofuels provide the panorama of new fiscal opportunities for people in rural area for meeting their need and also the demand of the local market. Biofuels concern protection of the environment and job creation. Renewable energy sources are self-reliance resources, have the potential in energy management with less emissions of air pollutants. Biofuels are expected to reduce dependability on imported crude oil with connected economic susceptibility, reduce greenhouse gases, other pollutants and invigorate the economy by increasing demand and prices for agricultural products. The use of neat paradise tree oil and induction of eco-friendly material Hydrogen through inlet manifold in a constant pressure heat addition cycle engine (diesel engine) with optimized engine operating parameters such as injection timing, injection pressure and compression ratio. The results shows the heat utilization efficiency for neat vegetable oil is 29% and neat oil with 15% Hydrogen as 33%. The exhaust gas temperature (EGT) for 15% of H2 share as 450°C at full load and the heat release of 80J/deg. crank angle for 15% Hydrogen energy share. PMID:26025643

  4. Study of Compton suppression for use in spent nuclear fuel assay

    NASA Astrophysics Data System (ADS)

    Bender, Sarah

    The focus of this study has been to assess Compton suppressed gamma-ray detection systems for the multivariate analysis of spent nuclear fuel. This objective has been achieved using direct measurement of samples of irradiated fuel elements in two geometrical configurations with Compton suppression systems. In order to address the objective to quantify the number of additionally resolvable photopeaks, direct Compton suppressed spectroscopic measurements of spent nuclear fuel in two configurations were performed: as intact fuel elements and as dissolved feed solutions. These measurements directly assessed and quantified the differences in measured gamma-ray spectrum from the application of Compton suppression. Several irradiated fuel elements of varying cooling time from the Penn State Breazeale Reactor spent fuel inventory were measured using three Compton suppression systems that utilized different primary detectors: HPGe, LaBr3, and NaI(Tl). The application of Compton suppression using a LaBr3 primary detector to the measurement of the current core fuel element, which presented the highest count rate, allowed four additional spectral features to be resolved. In comparison, the HPGe-CSS was able to resolve eight additional photopeaks as compared to the standalone HPGe measurement. Measurements with the NaI(Tl) primary detector were unable to resolve any additional peaks, due to its relatively low resolution. Samples of Approved Test Material (ATM) commercial fuel elements were obtained from Pacific Northwest National Laboratory. The samples had been processed using the beginning stages of the PUREX method and represented the unseparated feed solution from a reprocessing facility. Compton suppressed measurements of the ATM fuel samples were recorded inside the guard detector annulus, to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Photopeak losses were observed in the measurements of the dissolved ATM

  5. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  6. Phosphazene additives

    SciTech Connect

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  7. Worker exposure for at-reactor management of spent nuclear fuel.

    PubMed

    Weck, Philippe F

    2013-09-01

    The radiological impact on workers associated with spent nuclear fuel dry storage operations at reactor sites is discussed. The resulting doses to workers exposed to external radiation include the dose during dry storage system loading, unloading and handling activities, the dose associated with independent spent fuel storage installation (ISFSI) operations, maintenance and surveillance activities, and the dose associated with additional ISFSI construction. Comprehensive dose estimates are reported based on previous radiation surveys. PMID:23564883

  8. Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

    SciTech Connect

    Cunningham, M.E.; Thomas, L.E.

    1995-06-01

    The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0{sub 2}) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations.

  9. Spent-fuel cooling curve for safeguard applications of gross-gamma measurements

    SciTech Connect

    Rinard, P.

    1983-04-01

    Gross-gamma detectors can be used to gather data from spent-fuel assemblies in a simple and rapid manner. Using these data, inspectors can generate a power-law curve to check the consistency of the declared values with the measured values; points outside the curve indicate erroneously declared values or removal of material. Simple types of erroneously declared values can be detected immediately, whereas subtle types may require a second measurement and more subtle types may escape detection. If measurements of passive emissions of neutrons from the assemblies are made in addition to the gamma measurements, the values of the exposures and cooling times can be estimated independent of the operator-declared values. Although not yet demonstrated, it may be possible to obtain crude estimates of the exposures and cooling times from the gamma measurments alone.

  10. A study on the expulsion of iodine from spent-fuel solutions

    SciTech Connect

    Sakurai, Tsutomu; Takahashi, Akira; Ishikawa, Niroh

    1995-02-01

    During dissolution of spent nuclear fuels, some radioiodine remains in spent-fuel solutions. Its expulsion to dissolver off-gas is important to minimize iodine escape to the environment. In our current work, the iodine remaining in spent-fuel solutions varied from 0 to 10% after dissolution of spent PWR-fuel specimens (approximately 3 g each). The amount remaining probably was dependent upon the dissolution time required. The cause is ascribable to the increased nitrous acid concentration that results from NOx generated during dissolution. The presence of nitrous acid was confirmed spectrophotometrically in an NO-HNO{sub 3} system at 100{degrees}C. Experiments examining NOx concentration versus the quantity of iodine in a simulated spent-fuel solution indicate that iodine (I{minus}) in spent fuels is subjected to the following three reactions: (1) oxidation into I{sub 2} by nitric acid, (2) oxidation into I{sub 2} by nitrous acid arising from NOx, and (3) formation of colloidal iodine (AgI, PdI{sub 2}), the major iodine species in a spent-fuel solution. Reaction (2) competes with reaction (3) to control the quantity of iodine remaining in solution. The following two-step expulsion process to remove iodine from a spent-fuel solution was derived from these experiments: Step One - Heat spent-fuel solutions without NOx sparging. When aged colloidal iodine is present, an excess amount of iodate should be added to the solution. Step Two - Sparge the fuel solution with NOx while heating. Effect of this new method was confirmed by use of a spent PWR-fuel solution.

  11. The effect of additional noradrenergic and serotonergic depletion on a lateralised choice reaction time task in rats with nigral 6-OHDA lesions.

    PubMed

    Lindgren, Hanna S; Demirbugen, Merve; Bergqvist, Filip; Lane, Emma L; Dunnett, Stephen B

    2014-03-01

    Parkinson's disease (PD) patients often suffer from visuospatial deficits, which have been considered a disruption of the representation of external space. The lateralised choice reaction time (CRT) task is an operant task for rodents in which similar deficits can be assessed. It has been demonstrated that specific parameters in this task is disrupted after unilateral injections of 6-hydroxydopamine (6-OHDA), which have been associated with the dopamine (DA) depletion that inevitably follows this type of lesion. However, studies have demonstrated that this type of lesion also affects the serotonergic (5HT) and noradrenergic (NA) systems. However, the impact of these systems on parameters in the CRT task had not yet been investigated. To this end, rats were pretrained on the CRT task before receiving selective lesions of the DAergic system, either alone or in combination with depletion of the NA or 5HT system. All rats with a 6-OHDA lesion displayed a gradual decline in the selection, initiation and execution of lateralised movements compared to sham-lesion controls on the side contralateral to the lesion. They also displayed a reduced number of useable trials as well as an increased number of procedural errors. Interestingly, the group with an additional noradrenergic lesion was significantly slower in reacting to lateralised stimuli throughout the testing period compared to the other two groups with a 6-OHDA lesion. There was however no difference between the three different lesion groups in the other parameters assessed in the task. These data confirm previous findings demonstrating that the majority of the parameters assessed in the lateralised CRT task are strongly dependent on DA. However, this study has also shown that the NAergic system may play an important role in contributing to the attentive performance influencing the capacity to react to the presented lateralised stimuli. PMID:24333808

  12. Gamma Ray Mirrors for Direct Measurement of Spent Nuclear Fuel

    SciTech Connect

    Pivovaroff, Dr. Michael J.; Ziock, Klaus-Peter; Harrison, Mark J; Soufli, Regina

    2014-01-01

    Direct measurement of the amount of Pu and U in spent nuclear fuel represents a challenge for the safeguards community. Ideally, the characteristic gamma-ray emission lines from different isotopes provide an observable suitable for this task. However, these lines are generally lost in the fierce flux of radiation emitted by the fuel. The rates are so high that detector dead times limit measurements to only very small solid angles of the fuel. Only through the use of carefully designed view ports and long dwell times are such measurements possible. Recent advances in multilayer grazing-incidence gamma-ray optics provide one possible means of overcoming this difficulty. With a proper optical and coating design, such optics can serve as a notch filter, passing only narrow regions of the overall spectrum to a fully shielded detector that does not view the spent fuel directly. We report on the design of a mirror system and a number of experimental measurements.

  13. An environmental benign process for cobalt and lithium recovery from spent lithium-ion batteries by mechanochemical approach.

    PubMed

    Wang, Meng-Meng; Zhang, Cong-Cong; Zhang, Fu-Shen

    2016-05-01

    In the current study, an environmental benign process namely mechanochemical approach was developed for cobalt and lithium recovery from spent lithium-ion batteries (LIBs). The main merit of the process was that neither corrosive acid nor strong oxidant was applied. In the proposed process, lithium cobalt oxide (obtained from spent LIBs) was firstly co-grinded with various additives in a hermetic ball milling system, then Co and Li could be easily recovered by a water leaching procedure. It was found that EDTA was the most suitable co-grinding reagent, and 98% of Co and 99% of Li were respectively recovered under optimum conditions: LiCoO2 to EDTA mass ratio 1:4, milling time 4h, rotary speed 600r/min and ball-to-powder mass ratio 80:1, respectively. Mechanisms study implied that lone pair electrons provided by two nitrogen atoms and four hydroxyl oxygen atoms of EDTA could enter the empty orbit of Co and Li by solid-solid reaction, thus forming stable and water-soluble metal chelates Li-EDTA and Co-EDTA. Moreover, the separation of Co and Li could be achieved through a chemical precipitation approach. This study provides a high efficiency and environmentally friendly process for Co and Li recovery from spent LIBs. PMID:26965214

  14. Dry transfer system for spent fuel: Project report, A system designed to achieve the dry transfer of bare spent fuel between two casks. Final report

    SciTech Connect

    Dawson, D.M.; Guerra, G.; Neider, T.; Shih, P.

    1995-12-01

    This report describes the system developed by EPRI/DOE for the dry transfer of spent fuel assemblies outside the reactor spent fuel pool. The system is designed to allow spent fuel assemblies to be removed from a spent fuel pool in a small cask, transported to the transfer facility, and transferred to a larger cask, either for off-site transportation or on-site storage. With design modifications, this design is capable of transferring single spent fuel assemblies from dry storage casks to transportation casks or visa versa. One incentive for the development of this design is that utilities with limited lifting capacity or other physical or regulatory constraints are limited in their ability to utilize the current, more efficient transportation and storage cask designs. In addition, DOE, in planning to develop and implement the multi-purpose canister (MPC) system for the Civilian Radioactive Waste Management System, included the concept of an on-site dry transfer system to support the implementation of the MPC system at reactors with limitations that preclude the handling of the MPC system transfer casks. This Dry Transfer System can also be used at reactors wi decommissioned spent fuel pools and fuel in dry storage in non-MPC systems to transfer fuel into transportation casks. It can also be used at off-reactor site interim storage facilities for the same purpose.

  15. Spent nuclear fuel disposal liability insurance

    SciTech Connect

    Martin, D.W.

    1984-01-01

    This thesis examines the social efficiency of nuclear power when the risks of accidental releases of spent fuel radionuclides from a spent fuel disposal facility are considered. The analysis consists of two major parts. First, a theoretical economic model of the use of nuclear power including the risks associated with releases of radionuclides from a disposal facility is developed. Second, the costs of nuclear power, including the risks associated with a radionuclide release, are empirically compared to the costs of fossil fuel-fired generation of electricity. Under the provisions of the Nuclear Waste Policy Act of 1982, the federally owned and operated spent nuclear fuel disposal facility is not required to maintain a reserve fund to cover damages from an accidental radionuclide release. Thus, the risks of a harmful radionuclide release are not included in the spent nuclear fuel disposal fee charged to the electric utilities. Since the electric utilities do not pay the full, social costs of spent fuel disposal, they use nuclear fuel in excess of the social optimum. An insurance mechanism is proposed to internalize the risks associated with spent fueled disposal. Under this proposal, the Federal government is required to insure the disposal facility against any liabilities arising from accidental releases of spent fuel radionuclides.

  16. Test plan for thermogravimetric analyses of BWR spent fuel oxidation

    SciTech Connect

    Einziger, R.E.

    1988-12-01

    Preliminary studies indicated the need for additional low-temperature spent fuel oxidation data to determine the behavior of spent fuel as a waste form for a tuffy repository. Short-term thermogravimetric analysis tests were recommended in a comprehensive technical approach as the method for providing scoping data that could be used to (1) evaluate the effects of variables such as moisture and burnup on the oxidation rate, (2) determine operative mechanisms, and (3) guide long-term, low-temperature oxidation testing. The initial test series studied the temperature and moisture effects on pressurized water reactor fuel as a function of particle and grain size. This document presents the test matrix for studying the oxidation behavior of boiling water reactor fuel in the temperature range of 140 to 225{degree}C. 17 refs., 7 figs., 3 tabs.

  17. Technical strategy for the management of INEEL spent nuclear fuel

    SciTech Connect

    1997-03-01

    This report presents evaluations, findings, and recommendations of the Idaho National Engineering and Environmental Laboratory (INEEL) Spent Nuclear Fuel Task Team. The technical strategy developed by the Task Team includes stabilization, near term storage, packaging, transport, and ultimate disposal. Key issues identified and discussed include waste characterization, criticality, packaging, waste form performance, and special fuels. Current plans focus on onsite needs, and include three central elements: (1) resolution of near-term vulnerabilities, (2) consolidation of storage locations, and (3) achieving dry storage in transportable packages. In addition to the Task Team report, appendices contain information on the INEEL spent fuel inventory; regulatory decisions and agreements; and analyses of criticality, packaging, storage, transportation, and system performance of a geological repository. 16 refs., 6 figs., 4 tabs.

  18. Research on Spent Fuel Storage and Transportation in CRIEPI (Part 2 Concrete Cask Storage)

    SciTech Connect

    Koji Shirai; Jyunichi Tani; Taku Arai; Masumi Watatu; Hirofumi Takeda; Toshiari Saegusa; Philip L. Winston

    2008-10-01

    Concrete cask storage has been implemented in the world. At a later stage of storage period, the containment of the canister may deteriorate due to stress corrosion cracking phenomena in a salty air environment. High resistant stainless steels against SCC have been tested as compared with normal stainless steel. Taking account of the limited time-length of environment with certain level of humidity and temperature range, the high resistant stainless steels will survive from SCC damage. In addition, the adhesion of salt from salty environment on the canister surface will be further limited with respect to the canister temperature and angle of the canister surface against the salty air flow in the concrete cask. Optional countermeasure against SCC with respect to salty air environment has been studied. Devices consisting of various water trays to trap salty particles from the salty air were designed to be attached at the air inlet for natural cooling of the cask storage building. Efficiency for trapping salty particles was evaluated. Inspection of canister surface was carried out using an optical camera inserted from the air outlet through the annulus of a concrete cask that has stored real spent fuel for more than 15 years. The camera image revealed no gross degradation on the surface of the canister. Seismic response of a full-scale concrete cask with simulated spent fuel assemblies has been demonstrated. The cask did not tip over, but laterally moved by the earthquake motion. Stress generated on the surface of the spent fuel assemblies during the earthquake motion were within the elastic region.

  19. Simulation of differential die-away instrument's response to asymmetrically burned spent nuclear fuel

    NASA Astrophysics Data System (ADS)

    Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; Svärd, Staffan Jacobsson; Jansson, Peter; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-07-01

    Previous simulation studies of Differential Die-Away (DDA) instrument's response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument's response to interrogation of asymmetrically burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs. The results of this study suggest that DDA instrument response depends on the position of the individual neutron detectors and in fact can be split in two modes. The first mode, measured by the back detectors, is not significantly sensitive to the spatial distribution of fissile isotopes and neutron absorbers, but rather reflects the total amount of both contributors as in the cases of symmetrically burned SFAs. In contrary, the second mode, measured by the front detectors, yields certain sensitivity to the orientation of the asymmetrically burned SFA inside the assaying instrument. This study thus provides evidence that the DDA instrument can potentially be utilized as necessary in both ways, i.e. a quick determination of the average SFA characteristics in a single assay, as well as a more detailed characterization involving several DDA observables through assay of the SFA from all of its four sides that can possibly map the burn-up distribution and/or identify diversion or

  20. ON-LINE MONITORING FOR CONTROL AND SAFEGUARDING OF RADIOCHEMICAL STREAMS AT SPENT FUEL REPROCESSING PLANT

    SciTech Connect

    Bryan, Samuel A.; Levitskaia, Tatiana G.; Lines, Amanda M.; Billing, Justin M.; Casella, Amanda J.; Johnsen, Amanda M.; Peterson, James M.; Thomas, Elizabeth M.

    2009-11-10

    Advanced techniques that enhance safeguarding of spent fuel reprocessing plants are urgently needed. Our approach is based on the prerequisite that real-time monitoring of solvent extraction flowsheets at a spent fuel reprocessing plant provides the unique capability to quickly detect unwanted manipulations with fissile isotopes present in the radiochemical streams during reprocessing activities. The methods used to monitor these processes must be robust and capable of withstanding harsh radiation and chemical environments. A new on-line monitoring system satisfying these requirements and featuring Raman spectroscopy combined with a Coriolis and conductivity probes recently has been developed by our research team for tank waste retrieval. It provides immediate chemical data and flow parameters of high-level radioactive waste streams with high brine content generated during retrieval activities from nuclear waste storage tanks at the Hanford Site. The nature of the radiochemical streams at the spent fuel reprocessing plant calls for additional spectroscopic information that can be gained by using Vis-NIR capabilities augmenting Raman spectroscopy. A fiber optic Raman probe allows monitoring of high concentration species encountered in both aqueous and organic phases within the UREX suite of flowsheets, including metal oxide ions, such as uranyl, components of the organic solvent, inorganic oxo-anions, and water. Actinides and lanthanides are monitored remotely by Vis-NIR spectroscopy in aqueous and organic phases. In this report, we present our results on spectroscopic measurements of simulant flowsheet solutions and commercial fuels designed to demonstrate the applicability of Raman and Vis-NIR spectroscopic analysis for actual dissolver feed solutions.

  1. Characterization of alloy particles extracted from spent nuclear fuel

    NASA Astrophysics Data System (ADS)

    Cui, D.; Rondinella, V. V.; Fortner, J. A.; Kropf, A. J.; Eriksson, L.; Wronkiewicz, D. J.; Spahiu, K.

    2012-01-01

    We characterized, for the first time, submicro- and nanosized fission product-alloy particles that were extracted nondestructively from spent nuclear fuel, in terms of noble metal (Mo-Ru-Tc-Rh-Pd-Te) composition, atomic level homogeneity and lattice parameters. The evidences obtained in this work contribute to an improved understanding of the redox chemistry of radionuclides in nuclear waste repository environments and, in particular, of the catalytic properties of these unique metal alloy particles.

  2. Spent Nuclear Fuel Project dose management plan

    SciTech Connect

    Bergsman, K.H.

    1996-03-01

    This dose management plan facilitates meeting the dose management and ALARA requirements applicable to the design activities of the Spent Nuclear Fuel Project, and establishes consistency of information used by multiple subprojects in ALARA evaluations. The method for meeting the ALARA requirements applicable to facility designs involves two components. The first is each Spent Nuclear Fuel Project subproject incorporating ALARA principles, ALARA design optimizations, and ALARA design reviews throughout the design of facilities and equipment. The second component is the Spent Nuclear Fuel Project management providing overall dose management guidance to the subprojects and oversight of the subproject dose management efforts.

  3. Design Verification Report Spent Nuclear Fuel (SNF) Project Canister Storage Building (CSB)

    SciTech Connect

    BAZINET, G.D.

    2000-11-03

    The Sub-project W379, ''Spent Nuclear Fuel Canister Storage Building (CSB),'' was established as part of the Spent Nuclear Fuel (SNF) Project. The primary mission of the CSB is to safely store spent nuclear fuel removed from the K Basins in dry storage until such time that it can be transferred to the national geological repository at Yucca Mountain Nevada. This sub-project was initiated in late 1994 by a series of studies and conceptual designs. These studies determined that the partially constructed storage building, originally built as part of the Hanford Waste Vitrification Plant (HWVP) Project, could be redesigned to safely store the spent nuclear fuel. The scope of the CSB facility initially included a receiving station, a hot conditioning system, a storage vault, and a Multi-Canister Overpack (MCO) Handling Machine (MHM). Because of evolution of the project technical strategy, the hot conditioning system was deleted from the scope and MCO welding and sampling stations were added in its place. This report outlines the methods, procedures, and outputs developed by Project W379 to verify that the provided Structures, Systems, and Components (SSCs): satisfy the design requirements and acceptance criteria; perform their intended function; ensure that failure modes and hazards have been addressed in the design; and ensure that the SSCs as installed will not adversely impact other SSCs. The original version of this document was prepared by Vista Engineering for the SNF Project. The purpose of this revision is to document completion of verification actions that were pending at the time the initial report was prepared. Verification activities for the installed and operational SSCs have been completed. Verification of future additions to the CSB related to the canister cover cap and welding fixture system and MCO Internal Gas Sampling equipment will be completed as appropriate for those components. The open items related to verification of those requirements are noted

  4. Time-Resolved XAFS Spectroscopic Studies of B-H and N-H Oxidative Addition to Transition Metal Catalysts Relevant to Hydrogen Storage

    SciTech Connect

    Bitterwolf, Thomas E.

    2014-12-09

    Successful catalytic dehydrogenation of aminoborane, H3NBH3, prompted questions as to the potential role of N-H oxidative addition in the mechanisms of these processes. N-H oxidative addition reactions are rare, and in all cases appear to involve initial dative bonding to the metal by the amine lone pairs followed by transfer of a proton to the basic metal. Aminoborane and its trimethylborane derivative block this mechanism and, in principle, should permit authentic N-H oxidative attrition to occur. Extensive experimental work failed to confirm this hypothesis. In all cases either B-H complexation or oxidative addition of solvent C-H bonds dominate the chemistry.

  5. PWR and BWR spent fuel assembly gamma spectra measurements

    DOE PAGESBeta

    Vaccaro, S.; Tobin, Stephen J.; Favalli, Andrea; Grogan, Brandon R.; Jansson, Peter; Liljenfeldt, Henrik; Mozin, Vladimir; Hu, Jianwei; Schwalbach, P.; Sjoland, A.; et al

    2016-07-17

    A project to research the application of nondestructive assay (NDA) to spent fuel assemblies is underway. The research team comprises the European Atomic Energy Community (EURATOM), embodied by the European Commission, DG Energy, Directorate EURATOM Safeguards; the Swedish Nuclear Fuel and Waste Management Company (SKB); two universities; and several United States national laboratories. The Next Generation of Safeguards Initiative–Spent Fuel project team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detectmore » the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. This study focuses on spectrally resolved gamma-ray measurements performed on a diverse set of 50 assemblies [25 pressurized water reactor (PWR) assemblies and 25 boiling water reactor (BWR) assemblies]; these same 50 assemblies will be measured with neutron-based NDA instruments and a full-length calorimeter. Given that encapsulation/repository and dry storage safeguards are the primarily intended applications, the analysis focused on the dominant gamma-ray lines of 137Cs, 154Eu, and 134Cs because these isotopes will be the primary gamma-ray emitters during the time frames of interest to these applications. This study addresses the impact on the measured passive gamma-ray signals due to the following factors: burnup, initial enrichment, cooling time, assembly type (eight different PWR and six different BWR fuel designs), presence of gadolinium rods, and anomalies in operating history. As a result, to compare the measured results with theory, a limited number of ORIGEN-ARP simulations were performed.« less

  6. Spent fuel transportation in the United States: commercial spent fuel shipments through December 1984

    SciTech Connect

    Not Available

    1986-04-01

    This report has been prepared to provide updated transportation information on light water reactor (LWR) spent fuel in the United States. Historical data are presented on the quantities of spent fuel shipped from individual reactors on an annual basis and their shipping destinations. Specifically, a tabulation is provided for each present-fuel shipment that lists utility and plant of origin, destination and number of spent-fuel assemblies shipped. For all annual shipping campaigns between 1980 and 1984, the actual numbers of spent-fuel shipments are defined. The shipments are tabulated by year, and the mode of shipment and the casks utilized in shipment are included. The data consist of the current spent-fuel inventories at each of the operating reactors as of December 31, 1984. This report presents historical data on all commercial spent-fuel transportation shipments have occurred in the United States through December 31, 1984.

  7. Waste/Rock Interactions Technology Program. Status report on LWR spent-fuel leach tests

    SciTech Connect

    Katayama, Y.B.; Bradley, D.J.; Harvey, C.O.

    1980-11-01

    Spent fuels with burnups of 9000, 28,000 and 54,500 MWd/MTU have been leach tested at 25/sup 0/C. Three leach-test procedures (Paige, IAEA and static) were used. IAEA and static tests were conducted in five different solutions: deionized water, sodium bicarbonate, sodium chloride, calcium chloride and Waste Isolation Pilot Plant B brine solutions. Elemental leach data are reported based on the release of /sup 90/Sr/sup +90/Y, /sup 106/Ru, /sup 137/Cs, /sup 144/Ce, /sup 154/Eu, /sup 239 +240/Pu, /sup 125/Sb, /sup 244/Cm, /sup 129/I, /sup 99/Tc, and total uranium. This is the first report on /sup 129/I and /sup 99/Tc from spent fuel. Termination of the Paige test showed that the plateout (radionuclide adsorption) on the test apparatus had negligible effect on the leach rate of cesium and plutonium, but a major (up to a factor of 50 times) effect on the curium leach rate. Three-hundred additional days of leach testing by the IAEA procedure, from 467 to 769 d, showed a continuation of the leaching trends observed during the first 467 d. Results from the first two static leach test series, 2 and 8 d, gave the /sup 129/I and /sup 99/Tc release numbers.

  8. Regeneration of ammonia borane spent fuel

    SciTech Connect

    Sutton, Andrew David; Davis, Benjamin L; Gordon, John C

    2009-01-01

    A necessary target in realizing a hydrogen (H{sub 2}) economy, especially for the transportation sector, is its storage for controlled delivery, presumably to an energy producing fuel cell. In this vein, the U.S. Department of Energy's Centers of Excellence (CoE) in Hydrogen Storage have pursued different methodologies, including metal hydrides, chemical hydrides, and sorbents, for the expressed purpose of supplanting gasoline's current > 300 mile driving range. Chemical H{sub 2} storage has been dominated by one appealing material, ammonia borane (H{sub 3}N-BH{sub 3}, AB), due to its high gravimetric capacity of H{sub 2} (19.6 wt %) and low molecular weight (30.7 g mol{sup -1}). In addition, AB has both hydridic and protic moieties, yielding a material from which H{sub 2} can be readily released in contrast to the loss of H{sub 2} from C{sub 2}H{sub 6} which is substantially endothermic. As such, a number of publications have described H{sub 2} release from amine boranes, yielding various rates depending on the method applied. The viability of any chemical H{sub 2} storage system is critically dependent on efficient recyclability, but reports on the latter subject are sparse, invoke the use of high energy reducing agents, and suffer from low yields. Our group is currently engaged in trying to find and fully demonstrate an energy efficient regeneration process for the spent fuel from H{sub 2} depleted AB with a minimum number of steps. Although spent fuel composition depends on the dehydrogenation method, we have focused our efforts on the spent fuel resulting from metal-based catalysis, which has thus far shown the most promise. Metal-based catalysts have produced the fastest rates for a single equivalent of H{sub 2} released from AB and up to 2.5 equiv. of H{sub 2} can be produced within 2 hours. While ongoing work is being carried out to tailor the composition of spent AB fuel, a method has been developed for regenerating the predominant product, polyborazylene

  9. Nuclear criticality safety studies applicable to spent fuel shipping cask designs and spent fuel storage

    SciTech Connect

    Tang, J.S.

    1980-11-01

    Criticality analyses of water-moderated and reflected arrays of LWR fresh and spent fuel assemblies were carried out in this study. The calculated results indicate that using the assumption of fresh fuel loading in spent fuel shipping cask design leads to assembly spacings which are about twice the spacings of spent fuel loadings. Some shipping cask walls of composite lead and water are more effective neutron reflectors than water of 30.48 cm (12 in).

  10. Rack for storing spent nuclear fuel elements

    DOEpatents

    Rubinstein, Herbert J.; Clark, Philip M.; Gilcrest, James D.

    1978-06-20

    A rack for storing spent nuclear fuel elements in which a plurality of aligned rows of upright enclosures of generally square cross-sectional areas contain vertically disposed fuel elements. The enclosures are fixed at the lower ends thereof to a base. Pockets are formed between confronting walls of adjacent enclosures for receiving high absorption neutron absorbers, such as Boral, cadmium, borated stainless steel and the like for the closer spacing of spent fuel elements.

  11. Spent nuclear fuel reprocessing modeling

    SciTech Connect

    Tretyakova, S.; Shmidt, O.; Podymova, T.; Shadrin, A.; Tkachenko, V.; Makeyeva, I.; Tkachenko, V.; Verbitskaya, O.; Schultz, O.; Peshkichev, I.

    2013-07-01

    The long-term wide development of nuclear power requires new approaches towards the realization of nuclear fuel cycle, namely, closed nuclear fuel cycle (CNFC) with respect to fission materials. Plant nuclear fuel cycle (PNFC), which is in fact the reprocessing of spent nuclear fuel unloaded from the reactor and the production of new nuclear fuel (NF) at the same place together with reactor plant, can be one variant of CNFC. Developing and projecting of PNFC is a complicated high-technology innovative process that requires modern information support. One of the components of this information support is developed by the authors. This component is the programme conducting calculations for various variants of process flow sheets for reprocessing SNF and production of NF. Central in this programme is the blocks library, where the blocks contain mathematical description of separate processes and operations. The calculating programme itself has such a structure that one can configure the complex of blocks and correlations between blocks, appropriate for any given flow sheet. For the ready sequence of operations balance calculations are made of all flows, i.e. expenses, element and substance makeup, heat emission and radiation rate are determined. The programme is open and the block library can be updated. This means that more complicated and detailed models of technological processes will be added to the library basing on the results of testing processes using real equipment, in test operating mode. The development of the model for the realization of technical-economic analysis of various variants of technologic PNFC schemes and the organization of 'operator's advisor' is expected. (authors)

  12. Molten tin reprocessing of spent nuclear fuel elements

    DOEpatents

    Heckman, Richard A.

    1983-01-01

    A method and apparatus for reprocessing spent nuclear fuel is described. Within a containment vessel, a solid plug of tin and nitride precipitates supports a circulating bath of liquid tin therein. Spent nuclear fuel is immersed in the liquid tin under an atmosphere of nitrogen, resulting in the formation of nitride precipitates. The layer of liquid tin and nitride precipitates which interfaces the plug is solidified and integrated with the plug. Part of the plug is melted, removing nitride precipitates from the containment vessel, while a portion of the plug remains solidified to support the liquid tin and nitride precipitates remaining in the containment vessel. The process is practiced numerous times until substantially all of the precipitated nitrides are removed from the containment vessel.

  13. Spent Fuel Reprocessing: More Value for Money Spent in a Geological Repository?

    SciTech Connect

    Kaplan, P.; Vinoche, R.; Devezeaux, J-G.; Bailly, F.

    2003-02-25

    Today, each utility or country operating nuclear power plants can select between two long-term spent fuel management policies: either, spent fuel is considered as waste to dispose of through direct disposal or, spent fuel is considered a resource of valuable material through reprocessing-recycling. Reading and listening to what is said in the nuclear community, we understand that most people consider that the choice of policy is, actually, a choice among two technical paths to handle spent fuel: direct disposal versus reprocessing. This very simple situation has been recently challenged by analysis coming from countries where both policies are on survey. For example, ONDRAF of Belgium published an interesting study showing that, economically speaking for final disposal, it is worth treating spent fuel rather than dispose of it as a whole, even if there is no possibility to recycle the valuable part of it. So, the question is raised: is there such a one-to-one link between long term spent fuel management political option and industrial option? The purpose of the presentation is to discuss the potential advantages and drawbacks of spent fuel treatment as an implementation of the policy that considers spent fuel as waste to dispose of. Based on technical considerations and industrial experience, we will study qualitatively, and quantitatively when possible, the different answers proposed by treatment to the main concerns of spent-fuel-as-a-whole geological disposal.

  14. Mobile Melt-Dilute Treatment for Russian Spent Nuclear Fuel

    SciTech Connect

    Peacock, H.

    2002-09-17

    Treatment of spent Russian fuel using a Melt-Dilute (MD) process is proposed to consolidate fuel assemblies into a form that is proliferation resistant and provides critically safety under storage and disposal configurations. Russian fuel elements contain a variety of fuel meat and cladding materials. The Melt-Dilute treatment process was initially developed for aluminum-based fuels so additional development is needed for several cladding and fuel meat combinations in the Russian fuel inventory (e.g. zirconium-clad, uranium-zirconium alloy fuel). A Mobile Melt-Dilute facility (MMD) is being proposed for treatment of spent fuels at reactor site storage locations in Russia; thereby, avoiding the costs of building separate treatment facilities at each site and avoiding shipment of enriched fuel assemblies over the road. The MMD facility concept is based on laboratory tests conducted at the Savannah River Technology Center (SRTC), and modular pilot-scale facilities constructed at the Savannah River Site for treatment of US spent fuel. SRTC laboratory tests have shown the feasibility of operating a Melt-Dilute treatment process with either a closed system or a filtered off-gas system. The proposed Mobile Melt-Dilute process is presented in this paper.

  15. Characterization of spent fuel approved testing material---ATM-105

    SciTech Connect

    Guenther, R.J.; Blahnik, D.E.; Campbell, T.K.; Jenquin, U.P.; Mendel, J.E.; Thomas, L.E.; Thornhill, C.K.

    1991-12-01

    The characterization data obtained to data are described for Approved Testing Material 105 (ATM-105), which is spent fuel from Bundles CZ346 and CZ348 of the Cooper Nuclear Power Plant, a boiling-water reactor. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory (PNL) on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well-characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) Program. ATM-105 consists of 88 full-length irradiated fuel rods with rod-average burnups of about 2400 GJ/kgM (28 MWd/kgM) and expected fission gas release of about 1%. Characterization data include (1) descriptions of as-fabricated fuel design, irradiation history, and subsequent storage and handling; (2) isotopic gamma scans; (3) fission gas analyses; (4) ceramography of the fuel and metallography of the cladding; (5) special fuel studies involving analytical transmission electron microscopy (AEM); (6) calculated nuclide inventories and radioactivities in the fuel and cladding; and (7) radiochemical analyses of the fuel and cladding. Additional analyses of the fuel are being conducted and will be included in planned revisions of this report.

  16. In situ time-resolved X-ray diffraction of tobermorite formation in autoclaved aerated concrete: Influence of silica source reactivity and Al addition

    SciTech Connect

    Matsui, Kunio; Kikuma, Jun; Tsunashima, Masamichi; Ishikawa, Tetsuji; Matsuno, Shin-ya; Ogawa, Akihiro; Sato, Masugu

    2011-05-15

    The hydrothermal formation of tobermorite during the processing of autoclaved aerated concrete was investigated by in situ X-ray diffraction (XRD) analysis. High-energy X-rays from a synchrotron radiation source in combination with a newly developed autoclave cell and a photon-counting pixel array detector were used. To investigate the effects of the silica source, reactive quartz from chert and less-reactive quartz from quartz sand were used as starting materials. The effect of Al addition on tobermorite formation was also studied. In all cases, C-S-H, hydroxylellestadite and katoite were clearly observed as intermediates. Acceleration of tobermorite formation by Al addition was clearly observed. However, Al addition did not affect the dissolution rate of quartz. Two pathways, via C-S-H and katoite, were also observed in the Al-containing system. These results suggest that the structure of initially formed C-S-H is important for the subsequent tobermorite formation reactions.

  17. Radionuclide release from research reactor spent fuel

    NASA Astrophysics Data System (ADS)

    Curtius, H.; Kaiser, G.; Müller, E.; Bosbach, D.

    2011-09-01

    Numerous investigations with respect to LWR fuel under non oxidizing repository relevant conditions were performed. The results obtained indicate slow corrosion rates for the UO 2 fuel matrix. Special fuel-types (mostly dispersed fuels, high enriched in 235U, cladded with aluminium) are used in German research reactors, whereas in German nuclear power plants, UO 2-fuel (LWR fuel, enrichment in 235U up to 5%, zircaloy as cladding) is used. Irradiated research reactor fuels contribute less than 1% to the total waste volume. In Germany, the state is responsible for fuel operation and for fuel back-end options. The institute for energy research (IEF-6) at the Research Center Jülich performs investigation with irradiated research reactor spent fuels under repository relevant conditions. In the study, the corrosion of research reactor spent fuel has been investigated in MgCl 2-rich salt brine and the radionuclide release fractions have been determined. Leaching experiments in brine with two different research reactor fuel-types were performed in a hot cell facility in order to determine the corrosion behaviour and the radionuclide release fractions. The corrosion of two dispersed research reactor fuel-types (UAl x-Al and U 3Si 2-Al) was studied in 400 mL MgCl 2-rich salt brine in the presence of Fe 2+ under static and initially anoxic conditions. Within these experimental parameters, both fuel types corroded in the experimental time period of 3.5 years completely, and secondary alteration phases were formed. After complete corrosion of the used research reactor fuel samples, the inventories of Cs and Sr were quantitatively detected in solution. Solution concentrations of Am and Eu were lower than the solubility of Am(OH) 3(s) and Eu(OH) 3(s) solid phases respectively, and may be controlled by sorption processes. Pu concentrations may be controlled by Pu(IV) polymer species, but the presence of Pu(V) and Pu(IV) oxyhydroxides species due to radiolytic effects cannot

  18. Handling encapsulated spent fuel in a geologic repository environment

    SciTech Connect

    Ballou, L.B.

    1983-02-01

    In support of the Spent Fuel Test-Climate at the U.S. Department of Energy`s Nevada Test Site, a spent-fuel canister handling system has been designed, deployed, and operated successfully during the past five years. This system transports encapsulated commercial spent-fuel assemblies between the packaging facility and the test site ({similar_to}100 km), transfers the canisters 420 m vertically to and from a geologic storage drift, and emplaces or retrieves the canisters from the storage holes in the floor of the drift. The spent-fuel canisters are maintained in a fully shielded configuration at all times during the handling cycle, permitting manned access at any time for response to any abnormal conditions. All normal operations are conducted by remote control, thus assuring as low as reasonably achievable exposures to operators; specifically, we have had no measurable exposure during 30 canister transfer operations. While not intended to be prototypical of repository handling operations, the system embodies a number of concepts, now demonstrated to be safe, reliable, and economical, which may be very useful in evaluating full-scale repository handling alternatives in the future. Among the potentially significant concepts are: Use of an integral shielding plug to minimize radiation streaming at all transfer interfaces. Hydraulically actuated transfer cask jacking and rotation features to reduce excavation headroom requirements. Use of a dedicated small diameter (0.5 m) drilled shaft for transfer between the surface and repository workings. A wire-line hoisting system with positive emergency braking device which travels with the load. Remotely activated grapples - three used in the system - which are insensitive to load orientation. Rail-mounted underground transfer vehicle operated with no personnel underground.

  19. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

    1987-01-01

    A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

  20. Recycling of spent adsorbents for oxyanions and heavy metal ions in the production of ceramics.

    PubMed

    Verbinnen, Bram; Block, Chantal; Van Caneghem, Jo; Vandecasteele, Carlo

    2015-11-01

    Spent adsorbents for oxyanion forming elements and heavy metals are classified as hazardous materials and they are typically treated by stabilization/solidification before landfilling. The use of lime or cement for stabilization/solidification entails a high environmental impact and landfilling costs are high. This paper shows that mixing spent adsorbents in the raw material for the production of ceramic materials is a valuable alternative to stabilize oxyanion forming elements and heavy metals. The produced ceramics can be used as construction material, avoiding the high economic and environmental impact of stabilization/solidification followed by landfilling. To study the stabilization of oxyanion forming elements and heavy metals during the production process, two series of experiments were performed. In the first series of experiments, the main pollutant, Mo was adsorbed onto iron-based adsorbents, which were then mixed with industrial sludge (3 w/w%) and heated at 1100°C for 30 min. Mo was chosen, as this element is easily adsorbed onto iron-based adsorbents and it is the element that is the most difficult to stabilize (i.e. the highest temperatures need to be reached before the concentrations in the leachate are reduced). Leaching concentration from the 97/3 sludge/adsorbent mixture before heating ranged between 85 and 154 mg/kg; after the heating process they were reduced to 0.42-1.48 mg/kg. Mo was actually stabilized, as the total Mo concentration after addition was not affected by the heat treatment. In the second series of experiments, the sludge was spiked with other heavy metals and oxyanion forming elements (Cr, Ni, Cu, Zn, As, Cd and Pb) in concentrations 5 times higher than the initial concentrations; after heat treatment the leachate concentrations were below the regulatory limit values. The incorporation of spent adsorbents in ceramic materials is a valuable and sustainable alternative to the existing treatment methods, saving raw materials in the

  1. Assessing the Feasibility of Using Neutron Resonance Transmission Analysis (NRTA) for Assaying Plutonium in Spent Fuel Assemblies

    SciTech Connect

    D. L. Chichester; J. W. Sterbentz

    2012-07-01

    Neutron resonance transmission analysis (NRTA) is an active-interrogation nondestructive assay (NDA) technique capable of assaying spent nuclear fuel to determine plutonium content. Prior experimental work has definitively shown the technique capable of assaying plutonium isotope composition in spent-fuel pins to a precision of approximately 3%, with a spatial resolution of a few millimeters. As a Grand Challenge to investigate NDA options for assaying spent fuel assemblies (SFAs) in the commercial fuel cycle, Idaho National Laboratory has explored the feasibility of using NRTA to assay plutonium in a whole SFA. The goal is to achieve a Pu assay precision of 1%. The NRTA technique uses low-energy neutrons from 0.1-40 eV, at the bottom end of the actinide-resonance range, in a time-of-flight arrangement. Isotopic composition is determined by relating absorption of the incident neutrons to the macroscopic cross-section of the actinides of interest in the material, and then using this information to determine the areal density of the isotopes in the SFA. The neutrons used for NRTA are produced using a pulsed, accelerator-based neutron source. Distinguishable resonances exist for both the plutonium (239,240,241,242Pu) and uranium (235,236,238U) isotopes of interest in spent fuel. Additionally, in this energy range resonances exists for six important fission products (99Tc, 103Rh, 131Xe, 133Cs, 145Nd, and 152Sm) which provide additional information to support spent fuel plutonium assay determinations. Based on extensive modeling of the problem using Monte Carlo-based simulation codes, our preliminary results suggest that by rotating an SFA to acquire four symmetric views, sufficient neutron transmission can be achieved to assay a SFA. In this approach multiple scan information for the same pins may also be unfolded to potentially allow the determination of plutonium for sub-regions of the assembly. For a 17 ? 17 pressurized water reactor SFA, a simplistic preliminary

  2. Code System to Calculate Radiation Dose Rates Relative to Spent Fuel Shipping Casks.

    1993-05-20

    Version 00 QBF calculates and plots in a short running time, three dimensional radiation dose rate distributions in the form of contour maps on specified planes resulting from cylindrical sources loaded into vehicles or ships. Shielding effects by steel walls and shielding material layers are taken into account in addition to the shadow effect among casks. This code system identifies the critical points on which to focus when designing the radiation shielding structure and wheremore » each of the spent fuel shipping casks should be stored. The code GRAPH reads the output data file of QBF and plots it using the HGX graphics library. QBF unifies the functions of the SMART and MANYCASK codes included in CCC-482.« less

  3. Potential applications of sonochemistry in spent nuclear fuel reprocessing: a short review.

    PubMed

    Nikitenko, S I; Venault, L; Pflieger, R; Chave, T; Bisel, I; Moisy, P

    2010-08-01

    The industrial treatment of spent nuclear fuel is based upon a hydrometallurgical process in nitric acid medium. In order to minimize the volume of radioactive waste it seems interesting to generate the reactive species in situ in such solutions using ultrasonic irradiation without addition of salt-forming reagents. This review summarizes for the first time the versatile sonochemical processes with uranium, neptunium and plutonium in homogeneous nitric acid solutions and heterogeneous systems. The dissolution of refractory solids, ultrasonically driven liquid-liquid extraction and the sonochemical degradation of the volatile products of organic solvent radiolysis issued from PUREX process are considered. Also the guidelines for required further work to ensure successful application of the studied processes at industrial scale are discussed. PMID:20022548

  4. 5 CFR 2429.22 - Additional time for filing with the FLRA if you are filing in response to a document that has...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... effected. (c) Exception for applications for review filed under 5 CFR 2422.31. You do not get an additional 5 days to file an application for review of a Regional Director's Decision and Order under 5 CFR... rules that apply to filing exceptions to arbitration awards, see 5 CFR 2425.2(c)....

  5. 5 CFR 2429.22 - Additional time for filing with the FLRA if you are filing in response to a document that has...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... effected. (c) Exception for applications for review filed under 5 CFR 2422.31. You do not get an additional 5 days to file an application for review of a Regional Director's Decision and Order under 5 CFR... rules that apply to filing exceptions to arbitration awards, see 5 CFR 2425.2(c)....

  6. Time?

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    2013-09-01

    The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

  7. Evaluation of Nondestructive Assay/Nondestructive Examination Capabilities for Department of Energy Spent Nuclear Fuel

    SciTech Connect

    Luptak, A.J.; Bulmahn, K.D.

    1998-09-01

    This report summarizes an evaluation of the potential use of nondestructive assay (NDA) and nondestructive examination (NDE) technologies on DOE spent nuclear fuel (SNF). It presents the NDA/NDE information necessary for the National Spent Nuclear Fuel Program (NSNFP) and the SNF storage sites to use when defining that role, if any, of NDA/NDE in characterization and certification processes. Note that the potential role for NDA/NDE includes confirmatory testing on a sampling basis and is not restricted to use as a primary, item-specific, data collection method. The evaluation does not attempt to serve as a basis for selecting systems for development or deployment. Information was collected on 27 systems being developed at eight DOE locations. The systems considered are developed to some degree, but are not ready for deployment on the full range of DOE SNF and still require additional development. The system development may only involve demonstrating performance on additional SNF, packaging the system for deployment, and developing calibration standards, or it may be as extensive as performing additional basic research. Development time is considered to range from one to four years. We conclude that NDA/NDE systems are capable of playing a key role in the characterization and certification of DOE SNF, either as the primary data source or as a confirmatory test. NDA/NDE systems will be able to measure seven of the nine key SNF properties and to derive data for the two key properties not measured directly. The anticipated performance goals of these key properties are considered achievable except for enrichment measurements on fuels near 20% enrichment. NDA/NDE systems can likely be developed to measure the standard canisters now being considered for co-disposal of DOE SNF. This ability would allow the preparation of DOE SNF for storage now and the characterization and certification to be finalize later.

  8. Fusion option to dispose of spent nuclear fuel and transuranic elements

    SciTech Connect

    Gohar, Y.

    2000-02-10

    The fusion option is examined to solve the disposition problems of the spent nuclear fuel and the transuranic elements. The analysis of this report shows that the top rated solution, the elimination of the transuranic elements and the long-lived fission products, can be achieved in a fusion reactor. A 167 MW of fusion power from a D-T plasma for sixty years with an availability factor of 0.75 can transmute all the transuranic elements and the long-lived fission products of the 70,000 tons of the US inventory of spent nuclear fuel generated up to the year 2015. The operating time can be reduced to thirty years with use of 334 MW of fusion power, a system study is needed to define the optimum time. In addition, the fusion solution eliminates the need for a geological repository site, which is a major advantage. Meanwhile, such utilization of the fusion power will provide an excellent opportunity to develop fusion energy for the future. Fusion blankets with a liquid carrier for the transuranic elements can achieve a transmutation rate for the transuranic elements up to 80 kg/MW.y of fusion power with k{sub eff} of 0.98. In addition, the liquid blankets have several advantages relative to the other blanket options. The energy from this transmutation is utilized to produce revenue for the system. Molten salt (Flibe) and lithium-lead eutectic are identified as the most promising liquids for this application, both materials are under development for future fusion blanket concepts. The Flibe molten salt with transuranic elements was developed and used successfully as nuclear fuel for the molten salt breeder reactor in the 1960's.

  9. 78 FR 3853 - Retrievability, Cladding Integrity and Safe Handling of Spent Fuel at an Independent Spent Fuel...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-17

    ... COMMISSION 10 CFR Parts 71 and 72 Retrievability, Cladding Integrity and Safe Handling of Spent Fuel at an Independent Spent Fuel Storage Installation and During Transportation AGENCY: Nuclear Regulatory Commission... transport of spent nuclear fuel are separate from requirements for storage of spent nuclear fuel....

  10. Parametric study of radiation dose rates from rail and truck spent fuel transport casks

    SciTech Connect

    Parks, C.V.; Hermann, O.W.; Knight, J.R.

    1985-08-01

    Neutron and gamma dose rates from typical rail and truck spent fuel transport casks are reported for a variety of spent PWR fuel sources and cask conditions. The IF 300 rail cask and NLI 1/2 truck cask were selected for use as appropriate cask models. All calculations (cross section preparation, generation of spent fuel source terms, radiation transport calculations, and dose evaluation) were performed using various modules of the SCALE computational system. Conditions or parameters for which there were variations between cases include: detector distance from cask, spent fuel cooling time, the setting of fuel or neutron shielding cavities to either wet or dry, the cobalt content of assembly materials, normal fuel assemblies and consolidated cannisters, the geometry mesh interval size, and the order of the angular quadrature set. 13 refs., 6 figs., 9 tabs.

  11. Reexamination of spent fuel shipment risk estimates

    SciTech Connect

    COOK,J.R.; SPRUNG,JEREMY L.

    2000-04-25

    The risks associated with the transport of spent nuclear fuel by truck and rail have been reexamined and compared to results published in NUREG-O170 and the Modal Study. The full reexamination considered transport of PWR and BWR spent fuel by truck and rail in four generic Type B spent fuel casks. Because they are typical, this paper presents results only for transport of PWR spent fuel in steel-lead steel casks. Cask and spent fuel response to collision impacts and fires were evaluated by performing three-dimensional finite element and one-dimensional heat transport calculations. Accident release fractions were developed by critical review of literature data. Accident severity fractions were developed from Modal Study truck and rail accident event trees, modified to reflect the frequency of occurrence of hard and soft rock wayside route surfaces as determined by analysis of geographic data. Incident-free population doses and the population dose risks associated with the accidents that might occur during transport were calculated using the RADTRAN 5 transportation risk code. The calculated incident-free doses were compared to those published in NUREG-O170. The calculated accident dose risks were compared to dose risks calculated using NUREG-0170 and Modal Study accident source terms. The comparisons demonstrated that both of these studies made a number of very conservative assumptions about spent fuel and cask response to accident conditions, which caused their estimates of accident source terms, accident frequencies, and accident consequences to also be very conservative. The results of this study and the previous studies demonstrate that the risks associated with the shipment of spent fuel by truck or rail are very small.

  12. Microbial recovery of metals from spent catalysts

    SciTech Connect

    Sperl, P.L.; Sperl, G.T.

    1990-01-01

    The second quarter of 1990 was one of peripheral progress on the project of reclaiming molybdenum and nickel from spent coal liquefaction catalysts. We defined some important parameters for future research and we were able to clear up ambiguities in some of the past approaches and the problems uniquely associated with the ability of T. ferrooxidans to leach both Ni{sup ++} and molybdate from spent, alumina supported catalyst from the Wilsonville pilot project. We were also able to show the T. ferrooxidans was very sensitive to molybdate and extremely sensitive to tungstate, but showed relatively little sensitivity for the related elements chromate, vanadate and for the catalyst associated metal, Ni{sup ++}. There appears to be no negative synergistic effects between Ni{sup ++} and molybdate for growth, which bodies well for processes to reclaim both these metals from spent coal liquefaction catalysts. We have shown that T. ferrooxidans is indeed capable of leaching molybdate and Ni{sup ++} from spent catalysts if the catalyst is washed extensively with both an organic solvent such as tetrahydrofuran to remove the oily contaminants and an aqueous acidic medium to remove readily solubilized N{sup ++} and molybdate. It is possible to extract into an acidic medium enough molybdate from THF washed spent catalyst within 24 hr to completely inhibit the growth of all tested T. ferrooxidans strains. The stage is now set for the development of a molybdate tolerant strain to be used for actual leaching of the spent catalyst. We are currently seeking simpler ways of pretreating the raw spent catalyst in order to make it more amenable to microbial leaching and possibly produce an economic and feasible technology.

  13. Shipper/receiver difference verification of spent fuel by use of PDET

    SciTech Connect

    Ham, Y. S.; Sitaraman, S.

    2011-07-01

    the peak ratio of all the detector locations gives a unique signature that is sensitive to missing pins. The signature is principally dependent on the geometry of the detector locations, and little sensitive to enrichment or burn-up variations. A small variation in the fuel bundle, such as a few missing pins, changes the shape of the signature to enable detection. After verification of the non-diversion of spent fuel pins, the neutron signal and gamma signal are subsequently used to verify the consistency of the operator declaration on the fuel burn-up and cooling time. (authors)

  14. One-Time Addition of Nano-TiO2 Triggers Short-Term Responses in Benthic Bacterial Communities in Artificial Streams.

    PubMed

    Ozaki, Alexandra; Adams, Erin; Binh, Chu Thi Thanh; Tong, Tiezheng; Gaillard, Jean-François; Gray, Kimberly A; Kelly, John J

    2016-02-01

    Nano-TiO2 is an engineered nanomaterial whose production and use are increasing rapidly. Hence, aquatic habitats are at risk for nano-TiO2 contamination due to potential inputs from urban and suburban runoff and domestic wastewater. Nano-TiO2 has been shown to be toxic to a wide range of aquatic organisms, but little is known about the effects of nano-TiO2 on benthic microbial communities. This study used artificial stream mesocosms to assess the effects of a single addition of nano-TiO2 (P25 at a final concentration of 1 mg l(-1)) on the abundance, activity, and community composition of sediment-associated bacterial communities. The addition of nano-TiO2 resulted in a rapid (within 1 day) decrease in bacterial abundance in artificial stream sediments, but bacterial abundance returned to control levels within 3 weeks. Pyrosequencing of partial 16S rRNA genes did not indicate any significant changes in the relative abundance of any bacterial taxa with nano-TiO2 treatment, indicating that nano-TiO2 was toxic to a broad range of bacterial taxa and that recovery of the bacterial communities was not driven by changes in community composition. Addition of nano-TiO2 also resulted in short-term increases in respiration rates and denitrification enzyme activity, with both returning to control levels within 3 weeks. The results of this study demonstrate that single-pulse additions of nano-TiO2 to aquatic habitats have the potential to significantly affect the abundance and activity of benthic microbial communities and suggest that interactions of TiO2 nanoparticles with environmental matrices may limit the duration of their toxicity. PMID:26156053

  15. Site Specific Analyses of a Spent Nuclear Fuel Transportation Accident

    SciTech Connect

    Biwer, B. M.; Chen, S. Y.

    2003-02-24

    The number of spent nuclear fuel (SNF) shipments is expected to increase significantly during the time period that the United States' inventory of SNF is sent to a final disposal site. Prior work estimated that the highest accident risks of a SNF shipping campaign to the proposed geologic repository at Yucca Mountain were in the corridor states, such as Illinois. The largest potential human health impacts would be expected to occur in areas with high population densities such as urban settings. Thus, our current study examined the human health impacts from the most plausible severe SNF transportation accidents in the Chicago metropolitan area. The RISKIND 2.0 program was used to model site-specific data for an area where the largest impacts might occur. The results have shown that the radiological human health consequences of a severe SNF rail transportation accident on average might be similar to one year of exposure to natural background radiation for those persons living a nd working in the most affected areas downwind of the actual accident location. For maximally exposed individuals, an exposure similar to about two years of exposure to natural background radiation was estimated. In addition to the accident probabilities being very low (approximately 1 chance in 10,000 or less during the entire shipping campaign), the actual human health impacts are expected to be lower if any of the accidents considered did occur, because the results are dependent on the specific location and weather conditions, such as wind speed and direction, that were selected to maximize the results. Also, comparison of the results of longer duration accident scenarios against U.S. Environmental Protection Agency guidelines was made to demonstrate the usefulness of this site-specific analysis for emergency planning purposes.

  16. Safety Aspects of Dry Spent Fuel Storage and Spent Fuel Management - 13559

    SciTech Connect

    Botsch, W.; Smalian, S.; Hinterding, P.

    2013-07-01

    Dry storage systems are characterized by passive and inherent safety systems ensuring safety even in case of severe incidents or accidents. After the events of Fukushima, the advantages of such passively and inherently safe dry storage systems have become more and more obvious. As with the storage of all radioactive materials, the storage of spent nuclear fuel (SF) and high-level radioactive waste (HLW) must conform to safety requirements. Following safety aspects must be achieved throughout the storage period: - safe enclosure of radioactive materials, - safe removal of decay heat, - securing nuclear criticality safety, - avoidance of unnecessary radiation exposure. The implementation of these safety requirements can be achieved by dry storage of SF and HLW in casks as well as in other systems such as dry vault storage systems or spent fuel pools, where the latter is neither a dry nor a passive system. Furthermore, transport capability must be guaranteed during and after storage as well as limitation and control of radiation exposure. The safe enclosure of radioactive materials in dry storage casks can be achieved by a double-lid sealing system with surveillance of the sealing system. The safe removal of decay heat must be ensured by the design of the storage containers and the storage facility. The safe confinement of radioactive inventory has to be ensured by mechanical integrity of fuel assembly structures. This is guaranteed, e.g. by maintaining the mechanical integrity of the fuel rods or by additional safety measures for defective fuel rods. In order to ensure nuclear critically safety, possible effects of accidents have also to be taken into consideration. In case of dry storage it might be necessary to exclude the re-positioning of fissile material inside the container and/or neutron moderator exclusion might be taken into account. Unnecessary radiation exposure can be avoided by the cask or canister vault system itself. In Germany dry storage of SF in

  17. Quality of Learners' Time and Learning Performance beyond Quantitative Time-on-Task

    ERIC Educational Resources Information Center

    Romero, Margarida; Barbera, Elena

    2011-01-01

    Along with the amount of time spent learning (or time-on-task), the quality of learning time has a real influence on learning performance. Quality of time in online learning depends on students' time availability and their willingness to devote quality cognitive time to learning activities. However, the quantity and quality of the time spent by…

  18. Method for calculating the duration of vacuum drying of a metal-concrete container for spent nuclear fuel

    NASA Astrophysics Data System (ADS)

    Karyakin, Yu. E.; Nekhozhin, M. A.; Pletnev, A. A.

    2013-07-01

    A method for calculating the quantity of moisture in a metal-concrete container in the process of its charging with spent nuclear fuel is proposed. A computing method and results obtained by it for conservative estimation of the time of vacuum drying of a container charged with spent nuclear fuel by technologies with quantization and without quantization of the lower fuel element cluster are presented. It has been shown that the absence of quantization in loading spent fuel increases several times the time of vacuum drying of the metal-concrete container.

  19. Characterization of the neutron source term and multiplicity of a spent fuel assembly in support of NSDA safeguards of spent nuclear fuel

    SciTech Connect

    Richard, Joshua G; Fensin, Michael L; Tobin, Stephen J; Swinhoe, Martyn T; Menlove, Howard O; Baciak, James

    2010-01-01

    The gross neutron signal (GNS) is being considered as part of a fingerprinting or neutron balance approach to safeguards of spent nuclear fuel (SNF). Because the GNS is composed of many derivative components, understanding the time-dependent contribution of these derivative components is crucial to gauging the limitations of these approaches. The major components of the GNS are ({alpha}, n), spontaneous fission (SF), and multiplication neutrons. A methodology was developed to link MCNPX burnup output files to SOURCES4C input files for the purpose of automatically generating both the ({alpha}, n) and SF signals. Additional linking capabilities were developed to write MCNPX multiplication input files using the data obtained from the SOURCES4C output files. In this paper, the following are presented: (1) the relative contributions by source nuclide to the ({alpha}, n) signal as a function of initial enrichment/burnup/cooling time; (2) the relative contributions by source nuclide to the SF signal as a function of initial enrichment/burnup/cooling time; (3) the relative contributions by reaction type ({alpha},n vs. SF) to the GNS; and (4) the multiplication of the GNS as a function of initial enrichment/burnup/cooling time/counting environment. By developing these technologies to characterize the GNS, we can better evaluate the viability of the GNS fingerprint and neutron balance concepts for SNF.

  20. Achieving increased spent fuel storage capacity at the High Flux Isotope Reactor (HFIR)

    SciTech Connect

    Cook, D.H.; Chang, S.J.; Dabs, R.D.; Freels, J.D.; Morgan, K.A.; Rothrock, R.B.; Griess, J.C.

    1994-12-31

    The HFIR facility was originally designed to store approximately 25 spent cores, sufficient to allow for operational contingencies and for cooling prior to off-site shipment for reprocessing. The original capacity has now been increased to 60 positions, of which 53 are currently filled (September 1994). Additional spent cores are produced at a rate of about 10 or 11 per year. Continued HFIR operation, therefore, depends on a significant near-term expansion of the pool storage capacity, as well as on a future capability of reprocessing or other storage alternatives once the practical capacity of the pool is reached. To store the much larger inventory of spent fuel that may remain on-site under various future scenarios, the pool capacity is being increased in a phased manner through installation of a new multi-tier spent fuel rack design for higher density storage. A total of 143 positions was used for this paper as the maximum practical pool capacity without impacting operations; however, greater ultimate capacities were addressed in the supporting analyses and approval documents. This paper addresses issues related to the pool storage expansion including (1) seismic effects on the three-tier storage arrays, (2) thermal performance of the new arrays, (3) spent fuel cladding corrosion concerns related to the longer period of pool storage, and (4) impacts of increased spent fuel inventory on the pool water quality, water treatment systems, and LLLW volume.

  1. Naval Spent Nuclear Fuel disposal Container System Description Document

    SciTech Connect

    N. E. Pettit

    2001-07-13

    The Naval Spent Nuclear Fuel Disposal Container System supports the confinement and isolation of waste within the Engineered Barrier System of the Monitored Geologic Repository (MGR). Disposal containers/waste packages are loaded and sealed in the surface waste handling facilities, transferred underground through the access drifts using a rail mounted transporter, and emplaced in emplacement drifts. The Naval Spent Nuclear Fuel Disposal Container System provides long term confinement of the naval spent nuclear fuel (SNF) placed within the disposal containers, and withstands the loading, transfer, emplacement, and retrieval operations. The Naval Spent Nuclear Fuel Disposal Container System provides containment of waste for a designated period of time and limits radionuclide release thereafter. The waste package maintains the waste in a designated configuration, withstands maximum credible handling and rockfall loads, limits the waste form temperature after emplacement, resists corrosion in the expected handling and repository environments, and provides containment of waste in the event of an accident. Each naval SNF disposal container will hold a single naval SNF canister. There will be approximately 300 naval SNF canisters, composed of long and short canisters. The disposal container will include outer and inner cylinder walls and lids. An exterior label will provide a means by which to identify a disposal container and its contents. Different materials will be selected for the waste package inner and outer cylinders. The two metal cylinders, in combination with the Emplacement Drift System, drip shield, and the natural barrier will support the design philosophy of defense-in-depth. The use of materials with different properties prevents a single mode failure from breaching the waste package. The inner cylinder and inner cylinder lids will be constructed of stainless steel while the outer cylinder and outer cylinder lids will be made of high-nickel alloy.

  2. Influence of physicochemical treatments on spent palladium based catalyst for catalytic oxidation of VOCs.

    PubMed

    Kim, Sang Chai; Nahm, Seung Won; Shim, Wang Geun; Lee, Jae Wook; Moon, Hee

    2007-03-01

    To recycle the spent catalyst for the removal of VOCs, the benzene, toluene, and xylene (BTX) complete oxidations were studied over pretreated palladium based spent catalyst in a fixed bed flow reactor system at atmospheric pressure. Two different pretreatment methods with gas (air and hydrogen) and acid aqueous solution (HCl, H(2)SO(4), HNO(3), H(3)PO(4) and CH(3)COOH) were used to investigate the catalytic activity of spent catalyst. The properties of the spent and pretreated Pd based catalyst were characterized by XRD, BET, TEM, ICP, and XPS. The results of light-off curves indicate that the catalytic activity of toluene oxidation for pretreated samples is in the order of hydrogen>air>HNO(3)>CH(3)COOH>H(2)SO(4)>H(3)PO(4)>HCl. In addition, the air and the acid aqueous pretreated catalyst activities were significantly decreased compared to that of the spent (or parent) catalyst. Moreover, hydrogen pretreated (or reduced) catalysts having mainly metallic form show the best performance in removing the toluene vapours compared to other pretreated samples. The reduction temperature made a significant difference in the catalytic performance of the spent catalyst pretreated with hydrogen. XPS results clearly supported that the palladium state of the spent catalysts pretreated at 300 degrees C was shifted more toward metallic form than other reduced catalysts. Furthermore, the results of a long-term test and catalytic activity of aromatic hydrocarbons also supported that the hydrogen pretreated spent catalyst was a good candidate for removing toxic compounds. PMID:16919389

  3. Regeneration of ammonia borane from spent fuel materials.

    PubMed

    Summerscales, Owen T; Gordon, John C

    2013-07-28

    A shift to the hydrogen economy requires the development of an effective hydrogen fuel carrier with high volumetric and gravimetric storage capacity. Ammonia borane (AB) has emerged as a leading candidate due to its light weight and multiple protic (N-H) and hydridic (B-H) hydrogens. As a consequence, much work has been directed towards fine tuning the release of H2 from AB, in addition to its regeneration from the dehydrogenated "spent fuel" materials. This review summarizes the development of these regeneration methodologies. PMID:23571860

  4. Microbiology of spent nuclear fuel storage basins.

    PubMed

    Santo Domingo, J W; Berry, C J; Summer, M; Fliermans, C B

    1998-12-01

    Microbiological studies of spent nuclear fuel storage basins at Savannah River Site (SRS) were performed as a preliminary step to elucidate the potential for microbial-influenced corrosion (MIC) in these facilities. Total direct counts and culturable counts performed during a 2-year period indicated microbial densities of 10(4) to 10(7) cells/ml in water samples and on submerged metal coupons collected from these basins. Bacterial communities present in the basin transformed between 15% and 89% of the compounds present in Biologtrade mark plates. Additionally, the presence of several biocorrosion-relevant microbial groups (i.e., sulfate-reducing bacteria and acid-producing bacteria) was detected with commercially available test kits. Scanning electron microscopy and X-ray spectra analysis of osmium tetroxide-stained coupons demonstrated the development of microbial biofilm communities on some metal coupons submerged for 3 weeks in storage basins. After 12 months, coupons were fully covered by biofilms, with some deterioration of the coupon surface evident at the microscopical level. These results suggest that, despite the oligotrophic and radiological environment of the SRS storage basins and the active water deionization treatments commonly applied to prevent electrochemical corrosion in these facilities, these conditions do not prevent microbial colonization and survival. Such microbial densities and wide diversity of carbon source utilization reflect the ability of the microbial populations to adapt to these environments. The presumptive presence of sulfate-reducing bacteria and acid-producing bacteria and the development of biofilms on submerged coupons indicated that an environment for MIC of metal components in the storage basins may occur. However, to date, there has been no indication or evidence of MIC in the basins. Basin chemistry control and corrosion surveillance programs instituted several years ago have substantially abated all corrosion mechanisms

  5. Reducing Perceptions of Time Required to Complete Math Assignments by Adding Problems to Assignments: A Synthesis of the Additive Interspersal Research

    ERIC Educational Resources Information Center

    Billington, Eric J.; Skinner, Christopher H.

    2006-01-01

    Results from nine experiments were analyzed to evaluate the relationship between relative problem completion rates (RPCR) and judgments of time involving mathematics assignments. For each experiment, control assignments contained only target mathematics computation or word problems. Matched experimental assignments contained similar target…

  6. Implementation, Operation, and Management of a Non-Time Based School.

    ERIC Educational Resources Information Center

    Yarborough, L. Everett; Fox, Henry C.

    The Florida Department of Education has adopted state-wide goals and performance objectives which can ultimately serve as the basis of a non-time based school. In such a system, student performance will be the measure of an individual's success, as opposed to merely the number of years spent in the classroom; additional characteristics will…

  7. Geomechanics of the Spent Fuel Test: Climax

    SciTech Connect

    Wilder, D.G.; Yow, J.L. Jr.

    1987-07-01

    Three years of geomechanical measurements were made at the Spent Fuel Test-Climax (SFT-C) 1400 feet underground in fractured granitic rock. Heating of the rock mass resulted from emplacement of spent fuel as well as the heating by electrical heaters. Cooldown of the rock occurred after the spent fuel was removed and the heaters were turned off. The measurements program examines both gross and localized responses of the rock mass to thermal loading, to evaluate the thermomechanical response of sheared and fractured rock with that of relatively unfractured rock, to compare the magnitudes of displacements during mining with those induced by extensive heating of the rock mass, and to check assumptions regarding symmetry and damaged zones made in numerical modeling of the SFT-C. 28 refs., 113 figs., 10 tabs.

  8. Laser Surveillance System for Spent Fuel

    SciTech Connect

    Fiarman, S.; Zucker, M.S.; Bieber, A.M. Jr.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools (SFSP's) will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a full size laser system operating in air and have used an array of 6 zircaloy BWR tubes to simulate an assembly. The reflective signal from the zircaloy rods is a strong function of position of the assembly, but in all cases is easily discernable from the reference scan of the background with no assembly. A design for a SFSP laser surveillance system incorporating laser ranging is discussed. 10 figures.

  9. Spent Nuclear Fuel Alternative Technology Decision Analysis

    SciTech Connect

    Shedrow, C.B.

    1999-11-29

    The Westinghouse Savannah River Company (WSRC) made a FY98 commitment to the Department of Energy (DOE) to recommend a technology for the disposal of aluminum-based spent nuclear fuel (SNF) at the Savannah River Site (SRS). The two technologies being considered, direct co-disposal and melt and dilute, had been previously selected from a group of eleven potential SNF management technologies by the Research Reactor Spent Nuclear Fuel Task Team chartered by the DOE''s Office of Spent Fuel Management. To meet this commitment, WSRC organized the SNF Alternative Technology Program to further develop the direct co-disposal and melt and dilute technologies and ultimately provide a WSRC recommendation to DOE on a preferred SNF alternative management technology.

  10. Middle Management Time Usage.

    ERIC Educational Resources Information Center

    Dorin, Patrick C.; Mansergh, Gerald G.

    1980-01-01

    Elementary principals and industrial managers are involved in similar job activities, but they differ in the amount of time spent in each activity and in the degree of interaction with others. (Author/JM)

  11. The effect of activated carbon addition on membrane bioreactor processes for wastewater treatment and reclamation - A critical review.

    PubMed

    Skouteris, George; Saroj, Devendra; Melidis, Paraschos; Hai, Faisal I; Ouki, Sabèha

    2015-06-01

    This review concentrates on the effect of activated carbon (AC) addition to membrane bioreactors (MBRs) treating wastewaters. Use of AC-assisted MBRs combines adsorption, biodegradation and membrane filtration. This can lead to advanced removal of recalcitrant pollutants and mitigation of membrane fouling. The relative contribution of adsorption and biodegradation to overall removal achieved by an AC-assisted MBR process can vary, and "biological AC" may not fully develop due to competition of target pollutants with bulk organics in wastewater. Thus periodic replenishment of spent AC is necessary. Sludge retention time (SRT) governs the frequency of spent AC withdrawal and addition of fresh AC, and is an important parameter that significantly influences the performance of AC-assisted MBRs. Of utmost importance is AC dosage because AC overdose may aggravate membrane fouling, increase sludge viscosity, impair mass transfer and reduce sludge dewaterability. PMID:25801795

  12. Extending dry storage of spent LWR fuel for 100 years.

    SciTech Connect

    Einziger, R. E.

    1998-12-16

    Because of delays in closing the back end of the fuel cycle in the U.S., there is a need to extend dry inert storage of spent fuel beyond its originally anticipated 20-year duration. Many of the methodologies developed to support initial licensing for 20-year storage should be able to support the longer storage periods envisioned. This paper evaluates the applicability of existing information and methodologies to support dry storage up to 100 years. The thrust of the analysis is the potential behavior of the spent fuel. In the USA, the criteria for dry storage of LWR spent fuel are delineated in 10 CFR 72 [1]. The criteria fall into four general categories: maintain subcriticality, prevent the release of radioactive material above acceptable limits, ensure that radiation rates and doses do not exceed acceptable levels, and maintain retrievability of the stored radioactive material. These criteria need to be considered for normal, off-normal, and postulated accident conditions. The initial safety analysis report submitted for licensing evaluated the fuel's ability to meet the requirements for 20 years. It is not the intent to repeat these calculations, but to look at expected behavior over the additional 80 years, during which the temperatures and radiation fields are lower. During the first 20 years, the properties of the components may change because of elevated temperatures, presence of moisture, effects of radiation, etc. During normal storage in an inert atmosphere, there is potential for the cladding mechanical properties to change due to annealing or interaction with cask materials. The emissivity of the cladding could also change due to storage conditions. If there is air leakage into the cask, additional degradation could occur through oxidation in breached rods, which could lead to additional fission gas release and enlargement of cladding breaches. Air in-leakage could also affect cover gas conductivity, cladding oxidation, emissivity changes, and

  13. Evaluation of three composting systems for the management of spent coffee grounds.

    PubMed

    Liu, K; Price, G W

    2011-09-01

    This study was conducted to evaluate the optimum composting approach for the management of spent coffee grounds from the restaurant and ready-to-serve coffee industry. Three composting systems were assessed, including in-vessel composting, vermicomposting bins, and aerated static pile bin composting, over study periods ranging from 47 to 98 days. Total carbon content was reduced by 5-7% in the spent coffee ground treatments across the three composting systems. Nitrogen and other mineral nutrient contents were conserved or enhanced from the initial to the final composts in all the composting systems assessed. Earthworm growth and survival (15-80%) was reduced in all the treatments but mortality rates were lower in coffee treatments with cardboard additions. A decline in earthworm mortality with cardboard additions was the result of reduced exposure to organic compounds and chemicals released through the decomposition of spent coffee grounds. PMID:21704514

  14. Spent Nuclear Fuel Transport Reliability Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao

    2016-01-01

    This conference paper was orignated and shorten from the following publisehd PTS documents: 1. Jy-An Wang, Hao Jiang, and Hong Wang, Dynamic Deformation Simulation of Spent Nuclear Fuel Assembly and CIRFT Deformation Sensor Stability Investigation, ORNL/SPR-2015/662, November 2015. 2. Jy-An Wang, Hong Wang, Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications, NUREG/CR-7198, ORNL/TM-2014/214, May 2015. 3. Jy-An Wang, Hong Wang, Hao Jiang, Yong Yan, Bruce Bevard, Spent Nuclear Fuel Vibration Integrity Study 16332, WM2016 Conference, March 6 10, 2016, Phoenix, Arizona.

  15. Apparatus for shearing spent nuclear fuel assemblies

    DOEpatents

    Weil, Bradley S.; Metz, III, Curtis F.

    1980-01-01

    A method and apparatus are described for shearing spent nuclear fuel assemblies of the type comprising an array of fuel pins disposed within an outer metal shell or shroud. A spent fuel assembly is first compacted in a known manner and then incrementally sheared using fixed and movable shear blades having matched laterally projecting teeth which slidably intermesh to provide the desired shearing action. Incremental advancement of the fuel assembly after each shear cycle is limited to a distance corresponding to the lateral projection of the teeth to ensure fuel assembly breakup into small uniform segments which are amenable to remote chemical processing.

  16. Method for shearing spent nuclear fuel assemblies

    DOEpatents

    Weil, Bradley S.; Watson, Clyde D.

    1977-01-01

    A method is disclosed for shearing spent nuclear fuel assemblies of the type wherein a plurality of long metal tubes packed with ceramic fuel are supported in a spaced apart relationship within an outer metal shell or shroud which provides structural support to the assembly. Spent nuclear fuel assemblies are first compacted in a stepwise manner between specially designed gag-compactors and then sheared into short segments amenable to chemical processing by shear blades contoured to mate with the compacted surface of the fuel assembly.

  17. Spent Fuel Background Report Volume I

    SciTech Connect

    Abbott, D.

    1994-03-01

    This report is an overview of current spent nuclear fuel management in the DOE complex. Sources of information include published literature, internal DOE documents, interviews with site personnel, and information provided by individual sites. Much of the specific information on facilities and fuels was provided by the DOE sites in response to the questionnaire for data for spent fuels and facilities data bases. This information is as accurate as is currently available, but is subject to revision pending results of further data calls. Spent fuel is broadly classified into three categories: (a) production fuels, (b) special fuels, and (c) naval fuels. Production fuels, comprising about 80% of the total inventory, are those used at Hanford and Savannah River to produce nuclear materials for defense. Special fuels are those used in a wide variety of research, development, and testing activities. Special fuels include fuel from DOE and commercial reactors used in research activities at DOE sites. Naval fuels are those developed and used for nuclear-powered naval vessels and for related research and development. Given the recent DOE decision to curtail reprocessing, the topic of main concern in the management of spent fuel is its storage. Of the DOE sites that have spent nuclear fuel, the vast majority is located at three sites-Hanford, INEL, and Savannah River. Other sites with spent fuel include Oak Ridge, West Valley, Brookhaven, Argonne, Los Alamos, and Sandia. B&W NESI Lynchburg Technology Center and General Atomics are commercial facilities with DOE fuel. DOE may also receive fuel from foreign research reactors, university reactors, and other commercial and government research reactors. Most DOE spent fuel is stored in water-filled pools at the reactor facilities. Currently an engineering study is being performed to determine the feasibility of using dry storage for DOE-owned spent fuel currently stored at various facilities. Delays in opening the deep geologic

  18. Additive usage levels.

    PubMed

    Langlais, R

    1996-01-01

    With the adoption of the European Parliament and Council Directives on sweeteners, colours and miscellaneous additives the Commission is now embarking on the project of coordinating the activities of the European Union Member States in the collection of the data that are to make up the report on food additive intake requested by the European Parliament. This presentation looks at the inventory of available sources on additive use levels and concludes that for the time being national legislation is still the best source of information considering that the directives have yet to be transposed into national legislation. Furthermore, this presentation covers the correlation of the food categories as found in the additives directives with those used by national consumption surveys and finds that in a number of instances this correlation still leaves a lot to be desired. The intake of additives via food ingestion and the intake of substances which are chemically identical to additives but which occur naturally in fruits and vegetables is found in a number of cases to be higher than the intake of additives added during the manufacture of foodstuffs. While the difficulties are recognized in contributing to the compilation of food additive intake data, industry as a whole, i.e. the food manufacturing and food additive manufacturing industries, are confident that in a concerted effort, use data on food additives by industry can be made available. Lastly, the paper points out that with the transportation of the additives directives into national legislation and the time by which the food industry will be able to make use of the new food legislative environment several years will still go by; food additives use data by the food industry will thus have to be reviewed at the beginning of the next century. PMID:8792135

  19. Nuclear mass inventory, photon dose rate and thermal decay heat of spent research reactor fuel assemblies

    SciTech Connect

    Pond, R.B.; Matos, J.E.

    1996-05-01

    As part of the Department of Energy`s spent nuclear fuel acceptance criteria, the mass of uranium and transuranic elements in spent research reactor fuel must be specified. These data are, however, not always known or readily determined. It is the purpose of this report to provide estimates of these data for some of the more common research reactor fuel assembly types. The specific types considered here are MTR, TRIGA and DIDO fuel assemblies. The degree of physical protection given to spent fuel assemblies is largely dependent upon the photon dose rate of the spent fuel material. These data also, are not always known or readily determined. Because of a self-protecting dose rate level of radiation (dose rate greater than 100 ren-x/h at I m in air), it is important to know the dose rate of spent fuel assemblies at all time. Estimates of the photon dose rate for spent MTR, TRIGA and DIDO-type fuel assemblies are given in this report.

  20. Monte Carlo simulations of differential die-away instrument for determination of fissile content in spent fuel assemblies

    NASA Astrophysics Data System (ADS)

    Lee, Tae-Hoon; Menlove, Howard O.; Swinhoe, Martyn T.; Tobin, Stephen J.

    2011-10-01

    The differential die-away (DDA) technique has been simulated by using the MCNPX code to quantify its capability of measuring the fissile content in spent fuel assemblies. For 64 different spent fuel cases of various initial enrichment, burnup and cooling time, the count rate and signal to background ratios of the DDA system were obtained, where neutron backgrounds are mainly coming from the 244Cm of the spent fuel. To quantify the total fissile mass of spent fuel, a concept of the effective 239Pu mass was introduced by weighing the relative contribution to the signal of 235U and 241Pu compared to 239Pu and the calibration curves of DDA count rate vs. 239Pu eff were obtained by using the MCNPX code. With a deuterium-tritium (DT) neutron generator of 10 9 n/s strength, signal to background ratios of sufficient magnitude are acquired for a DDA system with the spent fuel assembly in water.

  1. Shippingport Spent Fuel Canister System Description

    SciTech Connect

    JOHNSON, D.M.

    2000-03-27

    In 1978 and 1979, a total of 72 blanket fuel assemblies (BFAs), irradiated during the operating cycles of the Shippingport Atomic Power Station's Pressurized Water Reactor (PWR) Core 2 from April 1965 to February 1974, were transferred to the Hanford Site and stored in underwater storage racks in Cell 2R at the 221-T Canyon (T-Plant). The initial objective was to recover the produced plutonium in the BFAs, but this never occurred and the fuel assemblies have remained within the water storage pool to the present time. The Shippingport Spent Fuel Canister (SSFC) is a confinement system that provides safe transport functions (in conjunction with the TN-WHC cask) and storage for the BFAs at the Canister Storage Building (CSB). The current plan is for these BFAs to be retrieved from wet storage and loaded into SSFCs for dry storage. The sealed SSFCs containing BFAs will be vacuum dried, internally backfilled with helium, and leak tested to provide suitable confinement for the BFAs during transport and storage. Following completion of the drying and inerting process, the SSFCs are to be delivered to the CSB for closure welding and long-term interim storage. The CSB will provide safe handling and dry storage for the SSFCs containing the BFAs. The purpose of this document is to describe the SSFC system and interface equipment, including the technical basis for the system, design descriptions, and operations requirements. It is intended that this document will be periodically updated as more equipment design and performance specification information becomes available.

  2. Levan as a new additive for colon-specific films: a new approach in the use of exopolysaccharides in time-dependent free films (Aminoalkyl Methacrylate Copolymer RS).

    PubMed

    dos-Santos, Leandro Freire; Gómez-Pineda, Edgardo Alfonso; Colabone-Celligoi, Maria Antonia-Pedrine; Cavalcanti, Osvaldo Albuquerque

    2013-09-01

    Time-dependent films, augmented with prebiotics, offer potential strategy for colon-specific controlled drug release. In this study, we produced films containing levan (L) and Aminoalkyl Methacrylate Copolymer RS (ER). Free films of ER combined with levan were produced by the casting process and characterized by the mobility of the polymeric matrix, hydration, differential scanning calorimetry (DSC) and thermogravimetry (TGA). The results of this study suggest that the exopolysaccharide levan can be used in combination with ER for colon specific materials. No evidence of incompatibilities between the levan and the synthetic polymer were detected, and levan improved the mobility of the polymeric matrix and the hydrophilicity of the system. Levan may have positively altered the density of the polymeric matrix, as visualized by thermal characterization. The endothermic decomposition peak was shifted with increasing amounts of levan. This new barrier polymer utilized a combination of time-dependent enzymatic mechanisms and can be considered promising for use in the coating of solid oral drugs for specific release. PMID:24035950

  3. Electrical-Discharge Machining With Additional Axis

    NASA Technical Reports Server (NTRS)

    Malinzak, Roger M.; Booth, Gary N.

    1991-01-01

    Proposed electrical-discharge-machining (EDM) apparatus uses moveable vertical wire as electrode. Wire positionable horizontally along one axis as it slides vertically past workpiece. Workpiece indexed in rotation about horizontal axis. Because of symmetry of parts, process used to make two such parts at a time by defining boundary between them. Advantages: cost of material reduced, imparts less residual stress to workpiece, and less time spent machining each part when parts produced in such symmetrical pairs.

  4. Spent-Fuel Test - Climax: An evaluation of the technical feasibility of geologic storage of spent nuclear fuel in granite: Executive summary of final results

    SciTech Connect

    Patrick, W.C.

    1986-09-02

    This summary volume outlines results that are covered in more detail in the final report of the Spent-Fuel Test - Climate project. The project was conducted between 1978 and 1983 in the granitic Climax stock at the Nevada Test Site. Results indicate that spent fuel can be safely stored for periods of years in this host medium and that nuclear waste so emplaced can be safely retrieved. We also evaluated the effects of heat and radiation (alone and in combination) on emplacement canisters and the surrounding rock mass. Storage of the spent-fuel affected the surrounding rock mass in measurable ways, but did not threaten the stability or safety of the facility at any time.

  5. Biotreatment of refinery spent sulfidic caustics

    SciTech Connect

    Sublette, K.L.; Rajganesh, B.; Woolsey, M.; Plato, A.

    1995-12-31

    Caustics are used in petroleum refinering to remove hydrogen sulfide from various hydrocarbon streams. Spent sulfidic caustics from two Conoco refineries have been successfully biotreated on bench and pilot scale, resulting in neutralization and removal of active sulfides. Sulfides were completely oxidized to sulfate by Thiobacillus denitrificans. Microbial oxidation of sulfide produced acid, which at least partially neutralized the caustic.

  6. Corrosion of spent Advanced Test Reactor fuel

    SciTech Connect

    Lundberg, L.B.; Croson, M.L.

    1994-11-01

    The results of a study of the condition of spent nuclear fuel elements from the Advanced Test Reactor (ATR) currently being stored underwater at the Idaho National Engineering Laboratory (INEL) are presented. This study was motivated by a need to estimate the corrosion behavior of dried, spent ATR fuel elements during dry storage for periods up to 50 years. The study indicated that the condition of spent ATR fuel elements currently stored underwater at the INEL is not very well known. Based on the limited data and observed corrosion behavior in the reactor and in underwater storage, it was concluded that many of the fuel elements currently stored under water in the facility called ICPP-603 FSF are in a degraded condition, and it is probable that many have breached cladding. The anticipated dehydration behavior of corroded spent ATR fuel elements was also studied, and a list of issues to be addressed by fuel element characterization before and after forced drying of the fuel elements and during dry storage is presented.

  7. Spent Nuclear Fuel Project Technical Databook

    SciTech Connect

    Reilly, M.A.

    1998-10-23

    The Spent Nuclear Fuel (SNF) Project Technical Databook is developed for use as a common authoritative source of fuel behavior and material parameters in support of the Hanford SNF Project. The Technical Databook will be revised as necessary to add parameters as their Databook submittals become available.

  8. Microbial recovery of metals from spent catalysts

    SciTech Connect

    Sperl, P.L.; Sperl, G.T.

    1990-01-01

    This project was initiated on October 1, 1989, for the purpose of recovering metals from spent coal liquefaction catalysts. Two catalyst types are the subject of the contract. The first is a Ni-Mo catalyst supported on alumina (Shell 324) as is used in a pilot scale coal liquefaction facility at Wilsonville, Alabama. This plant is run and operated by Southern Clean Fuels. A large sample of spent catalyst from this facility has been obtained. The second material is an unsupported ammonium molybdate catalyst used in a pilot process by the Department of Energy at the Pittsburgh Energy Technology Center. This material was obtained in late February 1990 but has not been pursued since the No content of this particular sample is too low for the current studies. The object of the contract is to treat these spent catalysts with microorganisms, especially Thiobacillus ferrooxidans, but also other Thiobacillus sp. and possibly Sulfolobus, to leach and remove the metals (Ni and Mo) from the spent catalysts into a form which can be readily recovered by conventional techniques.

  9. Spent nuclear fuel project product specification

    SciTech Connect

    PAJUNEN, A.L.

    1999-02-25

    This document establishes the limits and controls for the significant parameters that could potentially affect the safety and/or quality of the Spent Nuclear Fuel (SNF) packaged for processing, transport, and storage. The product specifications in this document cover the SNF packaged in Multi-Canister Overpacks to be transported throughout the SNF Project.

  10. Spent Nuclear Fuel (SNF) Project Product Specification

    SciTech Connect

    PAJUNEN, A.L.

    2000-01-20

    This document establishes the limits and controls for the significant parameters that could potentially affect the safety and/or quality of the Spent Nuclear Fuel (SNF) packaged for processing, transport, and storage. The product specifications in this document cover the SNF packaged in Multi-Canister Overpacks to be transported throughout the SNF Project.

  11. Hypocholestrolic effect of spent black tea leaves replaced with wheat bran in broiler ration.

    PubMed

    Rahman, Attaur; Rahman, Altafur; Ali, Gohar; Rahman, Shafeeur ur

    2016-03-01

    Black tea leaves (Camellia sinensis) have been known for many years in lowering cholesterol level. The purpose of the present study was to find the effects of spent black tea leaves as a substitute of wheat bran on cholesterol reduction in broiler chicks. For this purpose a total of hundred & fifty (150), day old broiler poultry chicks were purchased from the local market. The spent black tea leaves were collected from tea stalls. Chicks were randomly distributed into 5 main groups according to spent black tea leaves and wheat bran supplementation. Group R0 was kept as control, containing 120 g/kg wheat bran but no spent black tea leaves supplementation; group R30 received spent black tea leaves supplemented feed at the rate of 30 g/kg plus 90 g/kg wheat bran; group R60 received spent black tea leaves supplemented feed at the rate of 60 g/kg plus 60 g/kg wheat bran, group R90 received spent black tea leaves supplemented feed at the rate of 90 g/kg plus 30 g/kg wheat bran and group R120 received the spent black tea leaves supplemented feed at the rate of 120 g/kg plus 0 g/kg wheat bran respectively. Each group was carrying three replicate (10 chicks/replicate). The data was statistically analyzed, using completely randomized design. Mean liver cholesterol per chick on diet R30, R60, R90, and R120 was 102.22, 93.55, 76.22, 60.78 and 51.55 mg/100 g. Breast cholesterol per chick on diet R30, R60, R90, and R120 was 61.89, 51.33, 44.78, 37 and 32.77 mg/100 g. It was concluded that the addition of spent black tea leaves at the rate of 120 g/kg has significant effect on cholesterol reduction and over all performance of broiler chicks and recommended that expensive wheat bran can be effectively replaced by these spent black tea leaves in broiler poultry ration. PMID:27087091

  12. Numerical Estimation of the Spent Fuel Ratio

    SciTech Connect

    Lindgren, Eric R.; Durbin, Samuel; Wilke, Jason; Margraf, J.; Dunn, T. A.

    2016-01-01

    Sabotage of spent nuclear fuel casks remains a concern nearly forty years after attacks against shipment casks were first analyzed and has a renewed relevance in the post-9/11 environment. A limited number of full-scale tests and supporting efforts using surrogate materials, typically depleted uranium dioxide (DUO 2 ), have been conducted in the interim to more definitively determine the source term from these postulated events. However, the validity of these large- scale results remain in question due to the lack of a defensible spent fuel ratio (SFR), defined as the amount of respirable aerosol generated by an attack on a mass of spent fuel compared to that of an otherwise identical surrogate. Previous attempts to define the SFR in the 1980's have resulted in estimates ranging from 0.42 to 12 and include suboptimal experimental techniques and data comparisons. Because of the large uncertainty surrounding the SFR, estimates of releases from security-related events may be unnecessarily conservative. Credible arguments exist that the SFR does not exceed a value of unity. A defensible determination of the SFR in this lower range would greatly reduce the calculated risk associated with the transport and storage of spent nuclear fuel in dry cask systems. In the present work, the shock physics codes CTH and ALE3D were used to simulate spent nuclear fuel (SNF) and DUO 2 targets impacted by a high-velocity jet at an ambient temperature condition. These preliminary results are used to illustrate an approach to estimate the respirable release fraction for each type of material and ultimately, an estimate of the SFR. This page intentionally blank

  13. Establishment of cheatgrass (Bromus tectorum L. ) on spent oil shale from the Paraho process

    SciTech Connect

    George, M.R.; McKell, C.M.; Richardson, S.G.

    1981-04-01

    Experiments were conducted in a greenhouse with the following obtectives: (i) to study the emergence and seedling growth of cheatgrass (Bromus tectorum L.) in soil and in Paraho spent oil shale that was either leached, treated with sulfuric acid, covered with soil, or mixed with soil, and (ii) to study emergence and seedling growth of cheatgrass on spent shale that was fertilized with ammonium nitrate and triple superphosphate. The Ec/sub e/ of the spent shale was 14 mmhos/cm, the pH was 9 and the shale was low in plant available N and P. The soil from Federal oil shale lease tract U-a near Bonanza, Utah was a coarse textured alluvium with low moisture retention. Cheatgrass planted on soil alone and shale covered with soil had the highest emergence rates (75 to 86%) and produced the greatest total biomass (8.55 to 13.4 g). Seedling emergence rates on leached and unleached spent shale were 44% and 36%, respectively, and total biomass was < 1 g on either treatment. Seedlings failed to emerge on sulfuric acid-treated spent shale. The addition of sulfuric acid to spent shale increased the EC/sub e/ of the shale to over 21 mmhos/cm. Leached and unleached spent shale was fertilized with N at rates of 0, 28, and 56 kg/ha and P at rates of 0, 24.4, and 48.8 kg/ha. The total biomass for any fertilizer treatment was < 1 g. We conclude that covering shale disposal piles with topsoil may improve the site for successful invasion by a colonizing species such as cheatgrass.

  14. Impact of Nuclear Data Uncertainties on Calculated Spent Fuel Nuclide Inventories and Advanced NDA Instrument Response

    SciTech Connect

    Hu, Jianwei; Gauld, Ian C.

    2014-12-01

    The U.S. Department of Energy’s Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) project is nearing the final phase of developing several advanced nondestructive assay (NDA) instruments designed to measure spent nuclear fuel assemblies for the purpose of improving nuclear safeguards. Current efforts are focusing on calibrating several of these instruments with spent fuel assemblies at two international spent fuel facilities. Modelling and simulation is expected to play an important role in predicting nuclide compositions, neutron and gamma source terms, and instrument responses in order to inform the instrument calibration procedures. As part of NGSI-SF project, this work was carried out to assess the impacts of uncertainties in the nuclear data used in the calculations of spent fuel content, radiation emissions and instrument responses. Nuclear data is an essential part of nuclear fuel burnup and decay codes and nuclear transport codes. Such codes are routinely used for analysis of spent fuel and NDA safeguards instruments. Hence, the uncertainties existing in the nuclear data used in these codes affect the accuracies of such analysis. In addition, nuclear data uncertainties represent the limiting (smallest) uncertainties that can be expected from nuclear code predictions, and therefore define the highest attainable accuracy of the NDA instrument. This work studies the impacts of nuclear data uncertainties on calculated spent fuel nuclide inventories and the associated NDA instrument response. Recently developed methods within the SCALE code system are applied in this study. The Californium Interrogation with Prompt Neutron instrument was selected to illustrate the impact of these uncertainties on NDA instrument response.

  15. Impact of Nuclear Data Uncertainties on Calculated Spent Fuel Nuclide Inventories and Advanced NDA Instrument Response

    DOE PAGESBeta

    Hu, Jianwei; Gauld, Ian C.

    2014-12-01

    The U.S. Department of Energy’s Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) project is nearing the final phase of developing several advanced nondestructive assay (NDA) instruments designed to measure spent nuclear fuel assemblies for the purpose of improving nuclear safeguards. Current efforts are focusing on calibrating several of these instruments with spent fuel assemblies at two international spent fuel facilities. Modelling and simulation is expected to play an important role in predicting nuclide compositions, neutron and gamma source terms, and instrument responses in order to inform the instrument calibration procedures. As part of NGSI-SF project, this work was carried outmore » to assess the impacts of uncertainties in the nuclear data used in the calculations of spent fuel content, radiation emissions and instrument responses. Nuclear data is an essential part of nuclear fuel burnup and decay codes and nuclear transport codes. Such codes are routinely used for analysis of spent fuel and NDA safeguards instruments. Hence, the uncertainties existing in the nuclear data used in these codes affect the accuracies of such analysis. In addition, nuclear data uncertainties represent the limiting (smallest) uncertainties that can be expected from nuclear code predictions, and therefore define the highest attainable accuracy of the NDA instrument. This work studies the impacts of nuclear data uncertainties on calculated spent fuel nuclide inventories and the associated NDA instrument response. Recently developed methods within the SCALE code system are applied in this study. The Californium Interrogation with Prompt Neutron instrument was selected to illustrate the impact of these uncertainties on NDA instrument response.« less

  16. Spent fuel sabotage aerosol ratio program : FY 2004 test and data summary.

    SciTech Connect

    Brucher, Wenzel; Koch, Wolfgang; Pretzsch, Gunter Guido; Loiseau, Olivier; Mo, Tin; Billone, Michael C.; Autrusson, Bruno A.; Young, F. I.; Coats, Richard Lee; Burtseva, Tatiana; Luna, Robert Earl; Dickey, Roy R.; Sorenson, Ken Bryce; Nolte, Oliver; Thompson, Nancy Slater; Hibbs, Russell S.; Gregson, Michael Warren; Lange, Florentin; Molecke, Martin Alan; Tsai, Han-Chung

    2005-07-01

    This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. The program also provides significant technical and political benefits in international cooperation. We are quantifying the Spent Fuel Ratio (SFR), the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions, in a contained test chamber. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are the input for follow-on modeling studies to quantify respirable hazards, associated radiological risk assessments, vulnerability assessments, and potential cask physical protection design modifications. This document includes an updated description of the test program and test components for all work and plans made, or revised, during FY 2004. It also serves as a program status report as of the end of FY 2004. All available test results, observations, and aerosol analyses plus interpretations--primarily for surrogate material Phase 2 tests, series 2/5A through 2/9B, using cerium oxide sintered ceramic pellets are included. Advanced plans and progress are described for upcoming tests with unirradiated, depleted uranium oxide and actual spent fuel test rodlets. This spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of

  17. Recent advances in hardware and software are to improve spent fuel measurements

    SciTech Connect

    Staples, P.; Beddingfield, D. H.; Lestone, J. P.; Pelowitz, D. G.; Bytchkov, M.; Starovich, Z.; Harizanov, I.; Luna-Vellejo, J.; Lavender, C.

    2001-01-01

    Vast quantities of spent fuel are available for safeguard measurements, primarily in Commonwealth of Independent States (CIS) of the former Soviet Union. This spent fuel, much of which consists of long-cooling-time material, is going to become less unique in the world safeguards arena as reprocessing projects or permanent repositories continue to be delayed or postponed. The long cooling time of many of the spent fuel assemblies being prepared for intermediate term storage in the CIS countries promotes the possibility of increased accuracy in spent fuel assays. This improvement is made possible through the process of decay of the Curium isotopes and of fission products. An important point to consider for the future that could advance safeguards measurements for reverification and inspection would be to determine what safeguards requirements should be imposed upon this 'new' class of spent fuel, Improvements in measurement capability will obviously affect the safeguards requirements. What most significantly enables this progress in spent fuel measurements is the improvement in computer processing power and software enhancements leading to user-friendly Graphical User Interfaces (GUT's). The software used for these projects significantly reduces the IAEA inspector's time expenditure for both learning and operating computer and data acquisition systems, At the same time, by standardizing the spent fuel measurements, it is possible to increase reproducibility and reliability of the measurement data. Hardware systems will be described which take advantage of the increased computer control available to enable more complex measurement scenarios. A specific example of this is the active regulation of a spent fuel neutron coincident counter's {sup 3}He tubes high voltage, and subsequent scaling of measurement results to maintain a calibration for direct assay of the plutonium content of Fast Breeder Reactor spent fuel. The plutonium content has been successfully determined

  18. Room at the Mountain: Estimated Maximum Amounts of Commercial Spent Nuclear Fuel Capable of Disposal in a Yucca Mountain Repository

    SciTech Connect

    Kessler, John H.; Kemeny, John; King, Fraser; Ross, Alan M.; Ross, Benjamen

    2006-07-01

    The purpose of this paper is to present an initial analysis of the maximum amount of commercial spent nuclear fuel (CSNF) that could be emplaced into a geological repository at Yucca Mountain. This analysis identifies and uses programmatic, material, and geological constraints and factors that affect this estimation of maximum amount of CSNF for disposal. The conclusion of this initial analysis is that the current legislative limit on Yucca Mountain disposal capacity, 63,000 MTHM of CSNF, is a small fraction of the available physical capacity of the Yucca Mountain system assuming the current high-temperature operating mode (HTOM) design. EPRI is confident that at least four times the legislative limit for CSNF ({approx}260,000 MTHM) can be emplaced in the Yucca Mountain system. It is possible that with additional site characterization, upwards of nine times the legislative limit ({approx}570,000 MTHM) could be emplaced. (authors)

  19. Analysis of subcritical experiments using fresh and spent research reactor fuel assemblies

    NASA Astrophysics Data System (ADS)

    Zino, John Frederick

    1999-11-01

    This research investigated the concepts associated with crediting the burnup of spent nuclear fuel assemblies for the purposes of criticality safety. To accomplish this, a collaborative experimental research program was undertaken between Westinghouse, the University of Missouri Research Reactor (MURR) facility and Oak Ridge National Laboratory (ORNL). The purpose of the program was to characterize the subcritical behavior of a small array of fresh and spent MURR fuel assemblies using the 252Cf Source-driven noise technique. An aluminum test rig was built which was capable of holding up to four, highly enriched (93.15 wt.% 235U) MURR fuel assemblies in a 2 x 2 array. The rig was outfitted with one source and four detector drywells which allowed researchers to perform active neutron noise measurements on the array of fuel assemblies. The 1 atmosphere gas 3He neutron detectors used to perform the measurements were quenched with CF4 gas to allow improved discrimination of the neutron signals in the very high gamma-ray fields associated with spent fuel (˜8000 R/hr). In addition, the detector drywells were outfitted with 1″ lead collars to provide additional gamma-ray shielding from the spent fuel. Reactivity changes were induced in the subcritical lattice by replacing individual fresh assemblies (in a 4-assembly array) with spent assemblies of known, maximum burnup (143 Mw-D). The absolute and relative measured reactivity changes were then compared to those predicted by three-dimensional Monte Carlo calculations. The purpose of these comparisons was to investigate the accuracy of modern transport theory depletion calculations to accurately simulate the reactivity effects of burnup in spent nuclear fuel. A total of seven subcritical measurements were performed at the MURR reactor facility on July 20th and 27th, 1998. These measurements generated several estimates of prompt neutron decay constants (alpha) and ratios of spectral densities through frequency correlations

  20. Stressmeter placement at spent fuel test in climax granite

    SciTech Connect

    Abey, A.E.; Washington, H.R.

    1980-05-20

    Vibrating wire stressmeters were installed in the Spent Fuel Facility at the Nevada Test Site. These stressmeters will measure the changes in in situ stress during the five-year spent fuel test. Before installation, laboratory tests were conducted to study reproducibility of placement and to develop a program hopefully to reduce corrosion of the stressmeters while in place at the Spent Fuel Facility. These laboratory tests are discussed along with the installation of the stressmeters at the Spent Fuel Facility.

  1. Draft Environmental Impact Statement for the Treatment and Management of Sodium-Bonded Spent Nuclear Fuel

    SciTech Connect

    N /A

    1999-07-30

    This document summarizes the U.S. Department of Energy's ''Draft Environmental Impact Statement for the Treatment and Management of Sodium-Bonded Spent Nuclear Fuel''. In addition to information concerning the background, purpose and need for the proposed action, and the National Environmental Policy Act process, this summary describes the characteristics of sodium-bonded spent nuclear fuel, the proposed treatment methods, the proposed facilities, the alternatives considered, and the environmental consequences of these alternatives. A glossary is included at the end to assist the reader with some of the technical terms used in this document.

  2. 77 FR 75065 - Rescinding Spent Fuel Pool Exclusion Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-19

    ...; ] NUCLEAR REGULATORY COMMISSION 10 CFR Part 51 Rescinding Spent Fuel Pool Exclusion Regulations AGENCY... consideration of spent fuel pool storage impacts from license renewal environmental review. The petition was... for a waiver of the NRC's spent fuel pool exclusion regulations. The petitioner requested that, if...

  3. Bioleaching of spent refinery processing catalyst using Aspergillus niger with high-yield oxalic acid.

    PubMed

    Santhiya, Deenan; Ting, Yen-Peng

    2005-03-16

    A spent refinery processing catalyst was physically and chemically characterized, and subjected to one-step and two-step bioleaching processes using Aspergillus niger. During bioleaching of the spent catalysts of various particle sizes ("as received", 100-150 microm, <37 microm, and x =2.97 (average) microm) and pulp densities, the biomass dry weight and pH were determined. The corresponding leach liquor was analysed for excreted organic acids along with heavy metal values extracted from the catalyst. Chemical characterization of the spent catalyst confirmed the presence of heavy metal including Al (33.3%), Ni (6.09%) and Mo (13.72%). In general, the presence of the spent catalyst caused a decrease in the biomass yield and an increase in oxalic acid secretion by A. niger. The increase in oxalic acid secretion with a decrease in the catalyst particle size (up to <37 microm) led to corresponding increase in the extraction of metal values. The highest extraction of metal values from the spent catalyst (at 1% w/v pulp density and particle size <37 microm) were found to be 54.5% Al, 58.2% Ni and 82.3% Mo in 60 days of bioleaching. Oxalic acid secretion by A. niger in the presence of the spent catalyst was stimulated using 2-[N-Morpholino]ethanesulfonic acid (MES) buffer (pH 6), which resulted in comparable metal extraction (58% Al, 62.8% Ni and 78.9% Mo) in half the time required by the fungus in the absence of the buffer. Spent medium of A. niger grown in the absence and in the presence of MES buffer were found to leach almost similar amounts of Al and Ni, except Mo for which the spent medium of buffered culture was significantly more effective than the non-buffered culture. Overall, this study shows the possible use of bioleaching for the extraction of metal resources from spent catalysts. It also demonstrated the advantages of buffer-stimulated excretion of organic acids by A. niger in bioleaching of the spent catalyst. PMID:15664081

  4. Safeguards-by-Design: Guidance for Independent Spent Fuel Dry Storage Installations (ISFSI)

    SciTech Connect

    Trond Bjornard; Philip C. Durst

    2012-05-01

    This document summarizes the requirements and best practices for implementing international nuclear safeguards at independent spent fuel storage installations (ISFSIs), also known as Away-from- Reactor (AFR) storage facilities. These installations may provide wet or dry storage of spent fuel, although the safeguards guidance herein focuses on dry storage facilities. In principle, the safeguards guidance applies to both wet and dry storage. The reason for focusing on dry independent spent fuel storage installations is that this is one of the fastest growing nuclear installations worldwide. Independent spent fuel storage installations are typically outside of the safeguards nuclear material balance area (MBA) of the reactor. They may be located on the reactor site, but are generally considered by the International Atomic Energy Agency (IAEA) and the State Regulator/SSAC to be a separate facility. The need for this guidance is becoming increasingly urgent as more and more nuclear power plants move their spent fuel from resident spent fuel ponds to independent spent fuel storage installations. The safeguards requirements and best practices described herein are also relevant to the design and construction of regional independent spent fuel storage installations that nuclear power plant operators are starting to consider in the absence of a national long-term geological spent fuel repository. The following document has been prepared in support of two of the three foundational pillars for implementing Safeguards-by-Design (SBD). These are: i) defining the relevant safeguards requirements, and ii) defining the best practices for meeting the requirements. This document was prepared with the design of the latest independent dry spent fuel storage installations in mind and was prepared specifically as an aid for designers of commercial nuclear facilities to help them understand the relevant international requirements that follow from a country’s safeguards agreement with

  5. Severe accidents in spent fuel pools in support of generic safety, Issue 82

    SciTech Connect

    Sailor, V.L.; Perkins, K.R.; Weeks, J.R.; Connell, H.R.

    1987-07-01

    This investigation provides an assessment of the likelihood and consequences of a severe accident in a spent fuel storage pool - the complete draining of the pool. Potential mechanisms and conditions for failure of the spent fuel, and the subsequent release of the fission products, are identified. Two older PWR and BWR spent fuel storage pool designs are considered based on a preliminary screening study which tried to identify vulnerabilities. Internal and external events and accidents are assessed. Conditions which could lead to failure of the spent fuel Zircaloy cladding as a result of cladding rupture or as a result of a self-sustaining oxidation reaction are presented. Propagation of a cladding fire to older stored fuel assemblies is evaluated. Spent fuel pool fission product inventory is estimated and the releases and consequences for the various cladding scenarios are provided. Possible preventive or mitigative measures are qualitatively evaluated. The uncertainties in the risk estimate are large, and areas where additional evaluations are needed to reduce uncertainty are identified.

  6. Surrogate/spent fuel sabotage : aerosol ratio test program and Phase 2 test results.

    SciTech Connect

    Borek, Theodore Thaddeus III; Thompson, N. Slater; Sorenson, Ken Bryce; Hibbs, R.S.; Nolte, Oliver; Molecke, Martin Alan; Autrusson, Bruno; Young, F. I.; Koch, Wolfgang; Brochard, Didier; Pretzsch, Gunter Guido; Lange, Florentin

    2004-05-01

    A multinational test program is in progress to quantify the aerosol particulates produced when a high energy density device, HEDD, impacts surrogate material and actual spent fuel test rodlets. This program provides needed data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments; the program also provides significant political benefits in international cooperation. We are quantifying the spent fuel ratio, SFR, the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are crucial for predicting radiological impacts. This document includes a thorough description of the test program, including the current, detailed test plan, concept and design, plus a description of all test components, and requirements for future components and related nuclear facility needs. It also serves as a program status report as of the end of FY 2003. All available test results, observations, and analyses - primarily for surrogate material Phase 2 tests using cerium oxide sintered ceramic pellets are included. This spent fuel sabotage - aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC, and supported by both the U.S. Department of Energy and Nuclear Regulatory Commission.

  7. Environmental Assessment of Urgent-Relief Acceptance of Foreign Research Reactor Spent Nuclear Fuel

    SciTech Connect

    Not Available

    1994-04-01

    The Department of Energy has completed the Environmental Assessment (EA) of Urgent-Relief Acceptance of Foreign Research Reactor Spent Nuclear Fuel and issued a Finding of No Significant Impact (FONSI) for the proposed action. The EA and FONSI are enclosed for your information. The Department has decided to accept a limited number of spent nuclear fuel elements (409 elements) containing uranium that was enriched in the United States from eight research reactors in Austria, Denmark, Germany, Greece, the Netherlands, Sweden, and Switzerland. This action is necessary to maintain the viability of a major US nuclear weapons nonproliferation program to limit or eliminate the use of highly enriched uranium in civil programs. The purpose of the EA is to maintain the cooperation of the foreign research reactor operators with the nonproliferation program while a more extensive Environmental Impact Statement (EIS) is prepared on a proposed broader policy involving the acceptance of up to 15,000 foreign research reactor spent fuel elements over a 10 to 15 year period. Based on an evaluation of transport by commercial container liner or chartered vessel, five eastern seaboard ports, and truck and train modes of transporting the spent fuel overland to the Savannah River Sits, the Department has concluded that no significant impact would result from any combination of port and made of transport. In addition, no significant impacts were found from interim storage of spent fuel at the Savannah River Site.

  8. COBRA-SFS CYCLE 3. Thermal Hydraulic Analysis of Spent Fuel Casks

    SciTech Connect

    Rector, D.R.; Cuta, J.M.; Enderlin, C.W.

    1995-09-01

    COBRA-SFS (Spent Fuel Storage) is a code for thermal-hydraulic analysis of multi-assembly spent fuel storage and transportation systems. It uses a lumped parameter finite difference approach to predict flow and temperature distributions in spent fuel storage systems and fuel assemblies, under forced and natural convection heat transfer conditions. Derived from the COBRA family of codes, which have been extensively evaluated against in-pile and out-of-pile data, COBRA-SFS retains all the important features of the COBRA codes for single phase fluid analysis, and extends the range application to include problems with two-dimensional radiative and three-dimensional conductive heat transfer. COBRA-SFS has been used to analyze various single- and multi-assembly spent fuel storage systems containing unconsolidated and consolidated fuel rods, with a variety of fill media, including air, helium and vacuum. Cycle 0 of COBRA-SFS was released in 1986. Subsequent applications of the code led to development of additional capabilities, which resulted in the release of Cycle 1 in February 1989. Since then, the code has undergone an independent technical review as part of a submittal to the Nuclear Regulatory Commission for a generic license to apply the code to spent fuel storage system analysis. Modifications and improvements to the code have been combined to form Cycle 2. Cycle 3., the newest version of COBRA-SFS, has been validated and verified for transient applications, such as a storage cask thermal response to a pool fire.

  9. Criticality safety considerations in the geologic disposal of spent nuclear fuel assemblies

    SciTech Connect

    Gore, B.F.; McNair, G.W.; Heaberlin, S.W.

    1980-05-01

    Features of geologic disposal which hamper the demonstration that criticality cannot occur therein include possible changes of shape and form, intrusion of water as a neutron moderator, and selective leaching of spent fuel constituents. If the criticality safety of spent fuel disposal depends on burnup, independent measurements verifying the burnup should be performed prior to disposal. The status of nondestructive analysis method which might provide such verification is discussed. Calculations were performed to assess the potential for increasing the allowed size of a spent fuel disposal canister if potential water intrusion were limited by close-packing the enclosed rods. Several factors were identified which severely limited the potential of this application. The theoretical limit of hexagonal close-packing cannot be achieved due to fuel rod bowing. It is concluded that disposal canisters should be sized on the basis of assumed optimum moderation. Several topics for additional research were identified during this limited study.

  10. Analysis of near-term spent fuel transportation hardware requirements and transportation costs

    SciTech Connect

    Daling, P.M.; Engel, R.L.

    1983-01-01

    A computer model was developed to quantify the transportation hardware requirements and transportation costs associated with shipping spent fuel in the commercial nucler fuel cycle in the near future. Results from this study indicate that alternative spent fuel shipping systems (consolidated or disassembled fuel elements and new casks designed for older fuel) will significantly reduce the transportation hardware requirements and costs for shipping spent fuel in the commercial nuclear fuel cycle, if there is no significant change in their operating/handling characteristics. It was also found that a more modest cost reduction results from increasing the fraction of spent fuel shipped by truck from 25% to 50%. Larger transportation cost reductions could be realized with further increases in the truck shipping fraction. Using the given set of assumptions, it was found that the existing spent fuel cask fleet size is generally adequate to perform the needed transportation services until a fuel reprocessing plant (FRP) begins to receive fuel (assumed in 1987). Once the FRP opens, up to 7 additional truck systems and 16 additional rail systems are required at the reference truck shipping fraction of 25%. For the 50% truck shipping fraction, 17 additional truck systems and 9 additional rail systems are required. If consolidated fuel only is shipped (25% by truck), 5 additional rail casks are required and the current truck cask fleet is more than adequate until at least 1995. Changes in assumptions could affect the results. Transportation costs for a federal interim storage program could total about $25M if the FRP begins receiving fuel in 1987 or about $95M if the FRP is delayed until 1989. This is due to an increased utilization of federal interim storage facility from 350 MTU for the reference scenario to about 750 MTU if reprocessing is delayed by two years.

  11. Nuclear Solid Waste Processing Design at the Idaho Spent Fuels Facility

    SciTech Connect

    Dippre, M. A.

    2003-02-25

    A spent nuclear fuels (SNF) repackaging and storage facility was designed for the Idaho National Engineering and Environmental Laboratory (INEEL), with nuclear solid waste processing capability. Nuclear solid waste included contaminated or potentially contaminated spent fuel containers, associated hardware, machinery parts, light bulbs, tools, PPE, rags, swabs, tarps, weld rod, and HEPA filters. Design of the nuclear solid waste processing facilities included consideration of contractual, regulatory, ALARA (as low as reasonably achievable) exposure, economic, logistical, and space availability requirements. The design also included non-attended transfer methods between the fuel packaging area (FPA) (hot cell) and the waste processing area. A monitoring system was designed for use within the FPA of the facility, to pre-screen the most potentially contaminated fuel canister waste materials, according to contact- or non-contact-handled capability. Fuel canister waste materials which are not able to be contact-handled after attempted decontamination will be processed remotely and packaged within the FPA. Noncontact- handled materials processing includes size-reduction, as required to fit into INEEL permitted containers which will provide sufficient additional shielding to allow contact handling within the waste areas of the facility. The current design, which satisfied all of the requirements, employs mostly simple equipment and requires minimal use of customized components. The waste processing operation also minimizes operator exposure and operator attendance for equipment maintenance. Recently, discussions with the INEEL indicate that large canister waste materials can possibly be shipped to the burial facility without size-reduction. New waste containers would have to be designed to meet the drop tests required for transportation packages. The SNF waste processing facilities could then be highly simplified, resulting in capital equipment cost savings, operational

  12. On-Line Monitoring for Control and Safeguarding of Radiochemical Streams at Spent Fuel Reprocessing Plant

    SciTech Connect

    Bryan, Samuel A.; Levitskaia, Tatiana G.; Billing, Justin M.; Casella, Amanda J.; Johnsen, Amanda M.; Peterson, James M.

    2009-10-06

    Advanced techniques enabling enhanced safeguarding of the spent fuel reprocessing plants are urgently needed. Our approach is based on prerequisite that real time monitoring of the solvent extraction flowsheets provides unique capability to quickly detect unwanted manipulations with fissile isotopes present in the radiochemical streams during reprocessing activities. The methods used to monitor these processes must be robust and must be able to withstand harsh radiation and chemical environments. A new on-line monitoring system satisfying these requirements and featuring Raman spectroscopy combined with a Coriolis and conductivity probes, has been recently developed by our research team. It provides immediate chemical data and flow parameters of high-level radioactive waste streams with high brine content generated during retrieval activities from Hanford nuclear waste storage tanks. The nature of the radiochemical streams at the spent fuel reprocessing plant calls for additional spectroscopic information, which can be gained by the utilization of UV-vis-NIR capabilities. Raman and UV-vis-NIR spectroscopies are analytical techniques that have extensively been extensively applied for measuring the various organic and inorganic compounds including actinides. The corresponding spectrometers used under the laboratory conditions are easily convertible to the process-friendly configurations allowing remote measurements under the flow conditions. A fiber optic Raman probe allows monitoring of the high concentration species encountered in both aqueous and organic phases within the UREX suite of flowsheets, including metal oxide ions, such as uranyl, components of the organic solvent, inorganic oxo-anions, and water. The actinides and lanthanides are monitored remotely by UV-vis-NIR spectroscopy in aqueous and organic phases. In this report, we will present our recent results on spectroscopic measurements of simulant flowsheet solutions and commercial fuels available at

  13. DOE Spent Nuclear Fuel Information In Support of TSPA-VA

    SciTech Connect

    A. Brewer; D. Cresap; D. Fillmore; H. Loo; M. Ebner; R. McCormack

    1998-09-01

    RW has started the viability assessment (VA) effort to determine the feasibility of Yucca Mountain as the first geologic repository for spent nuclear fuel (SNF) and high-level waste. One component of the viability assessment will be a total system performance assessment (TSPA), based on the design concept and the scientific data and analysis available, describing the repository's probable behavior relative to the overall system performance standards. Thus, all the data collected from the Exploratory Studies Facility to-date have been incorporated into the latest TSPA model. In addition, the Repository Integration Program, an integrated probabilistic simulator, used in the TSPA has also been updated by Golder Associates Incorporated at December 1997. To ensure that the Department of Energy-owned (DOE-owned) SNF continues to be acceptable for disposal in the repository, it will be included in the TSPA-VA evaluation. A number of parameters are needed in the TSPA-VA models to predict the performance of the DOE-owned SNF materials placed into the potential repository. This report documents all of the basis and/or derivation for each of these parameters. A number of properties were not readily available at the time the TSPA-VA data was requested. Thus, expert judgement and opinion was utilized to determine a best property value. The performance of the DOE-owned SNF will be published as part of the TSPA-VA report. Each DOE site will be collecting better data as the DOE SNF program moves closer to repository license application. As required by the RW-0333P, the National Spent Nuclear Fuel Program will be assisting each site in qualifying the information used to support the performance assessment evaluations.

  14. Spent fuel and high-level radioactive waste transportation report

    SciTech Connect

    Not Available

    1989-11-01

    This publication is intended to provide its readers with an introduction to the issues surrounding the subject of transportation of spent nuclear fuel and high-level radioactive waste, especially as those issues impact the southern region of the United States. It was originally issued by the Southern States Energy Board (SSEB) in July 1987 as the Spent Nuclear Fuel and High-Level Radioactive Waste Transportation Primer, a document patterned on work performed by the Western Interstate Energy Board and designed as a ``comprehensive overview of the issues.`` This work differs from that earlier effort in that it is designed for the educated layman with little or no background in nuclear waste issues. In addition, this document is not a comprehensive examination of nuclear waste issues but should instead serve as a general introduction to the subject. Owing to changes in the nuclear waste management system, program activities by the US Department of Energy and other federal agencies and developing technologies, much of this information is dated quickly. While this report uses the most recent data available, readers should keep in mind that some of the material is subject to rapid change. SSEB plans periodic updates in the future to account for changes in the program. Replacement pages sew be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

  15. Spent fuel and high-level radioactive waste transportation report

    SciTech Connect

    Not Available

    1990-11-01

    This publication is intended to provide its readers with an introduction to the issues surrounding the subject of transportation of spent nuclear fuel and high-level radioactive waste, especially as those issues impact the southern region of the United States. It was originally issued by the Southern States Energy Board (SSEB) in July 1987 as the Spent Nuclear Fuel and High-Level Radioactive Waste Transportation Primer, a document patterned on work performed by the Western Interstate Energy Board and designed as a ``comprehensive overview of the issues.`` This work differs from that earlier effort in that it is designed for the educated layman with little or no background in nuclear waste issues. In addition, this document is not a comprehensive examination of nuclear waste issues but should instead serve as a general introduction to the subject. Owing to changes in the nuclear waste management system, program activities by the US Department of Energy and other federal agencies and developing technologies, much of this information is dated quickly. While this report uses the most recent data available, readers should keep in mind that some of the material is subject to rapid change. SSEB plans periodic updates in the future to account for changes in the program. Replacement pages will be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

  16. Spent Fuel and High-Level Radioactive Waste Transportation Report

    SciTech Connect

    Not Available

    1992-03-01

    This publication is intended to provide its readers with an introduction to the issues surrounding the subject of transportation of spent nuclear fuel and high-level radioactive waste, especially as those issues impact the southern region of the United States. It was originally issued by SSEB in July 1987 as the Spent Nuclear Fuel and High-Level Radioactive Waste Transportation Primer, a document patterned on work performed by the Western Interstate Energy Board and designed as a ``comprehensive overview of the issues.`` This work differs from that earlier effort in that it is designed for the educated layman with little or no background in nuclear waste Issues. In addition. this document is not a comprehensive examination of nuclear waste issues but should instead serve as a general introduction to the subject. Owing to changes in the nuclear waste management system, program activities by the US Department of Energy and other federal agencies and developing technologies, much of this information is dated quickly. While this report uses the most recent data available, readers should keep in mind that some of the material is subject to rapid change. SSEB plans periodic updates in the future to account for changes in the program. Replacement pages will be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

  17. Projected Source Terms for Potential Sabotage Events Related to Spent Fuel Shipments

    SciTech Connect

    Luna, R.E.; Neuhauser, K.S.; Vigil, M.G.

    1999-06-01

    Two major studies, one sponsored by the U.S. Department of Energy and the other by the U.S. Nuclear Regulatory Commission, were conducted in the late 1970s and early 1980s to provide information and source terms for an optimally successful act of sabotage on spent fuel casks typical of those available for use. This report applies the results of those studies and additional analysis to derive potential source terms for certain classes of sabotage events on spent fuel casks and spent fuel typical of those which could be shipped in the early decades of the 21st century. In addition to updating the cask and spent fuel characteristics used in the analysis, two release mechanisms not included in the earlier works were identified and evaluated. As would be expected, inclusion of these additional release mechanisms resulted in a somewhat higher total release from the postulated sabotage events. Although health effects from estimated releases were addressed in the earlier study conducted for U.S. Department of Energy, they have not been addressed in this report. The results from this report maybe used to estimate health effects.

  18. BR-100 spent fuel shipping cask development

    SciTech Connect

    McGuinn, E.J.; Childress, P.C.

    1990-01-01

    Continued public acceptance of commercial nuclear power is contingent to a large degree on the US Department of Energy (DOE) establishing an integrated waste management system for spent nuclear fuel. As part of the from-reactor transportation segment of this system, the B W Fuel Company (BWFC) is under contract to the DOE to develop a spent-fuel cask that is compatible with both rail and barge modes of transportation. Innovative design approaches were the keys to achieving a cask design that maximizes payload capacity and cask performance. The result is the BR-100, a 100-ton rail/barge cask with a capacity of 21 PWR or 52 BWR ten-year cooled, intact fuel assemblies. 3 figs.

  19. Code System for Spent Fuel Heating Analysis.

    1999-05-24

    Version 00 SFHA calculates steady-state fuel rod temperatures for hexagon and square-fuel bundles. The code is used to perform sensitivity studies and confirmatory analyses of results submitted by applicants for spent fuel storage licenses. All three modes of heat transfer are considered; radiation, convection, and conduction. Each is modeled separately. SFHA benchmark calculations were made with test data to validate the use of a simple one-dimensional heat transfer model for estimating fuel rod temperatures. Benchmarkmore » results show that SFHA is capable of calculating spent fuel rod temperatures for square and hexagonal fuel bundles under various environments for the consolidated or unconsolidated condition. The program is menu-driven and executes automatically after all required information is entered.« less

  20. Spent fuel container alignment device and method

    DOEpatents

    Jones, Stewart D.; Chapek, George V.

    1996-01-01

    An alignment device is used with a spent fuel shipping container including a plurality of fuel pockets for spent fuel arranged in an annular array and having a rotatable cover including an access opening therein. The alignment device includes a lightweight plate which is installed over the access opening of the cover. A laser device is mounted on the plate so as to emit a laser beam through a laser admittance window in the cover into the container in the direction of a pre-established target associated with a particular fuel pocket. An indexing arrangement on the container provides an indication of the angular position of the rotatable cover when the laser beam produced by the laser is brought into alignment with the target of the associated fuel pocket.

  1. Historical overview of domestic spent fuel shipments

    SciTech Connect

    Pope, R.B.; Wankerl, M.W. ); Armstrong, S.; Hamberger, C., Schmid, S. )

    1991-01-01

    The purpose of this paper is to provide available historical data on most commercial and research reactor spent fuel shipments that have been completed in the United States between 1964 and 1989. This information includes data on the sources of spent fuel that has been shipped, the types of shipping casks used, the number of fuel assemblies that have been shipped, and the number of shipments that have been made. The data are updated periodically to keep abreast of changes. Information on shipments is provided for planning purposes; to support program decisions of the US Department of Energy's (DOE's) Office of Civilian Radioactive Waste Management (OCRWM); and to inform interested members of the public, federal, state, and local government, Indian tribes, and the transportation community. 5 refs., 7 figs., 2 tabs.

  2. Spent Sealed Sources Management in Switzerland - 12011

    SciTech Connect

    Beer, H.F.

    2012-07-01

    Information is provided about the international recommendations for the safe management of disused and spent sealed radioactive sources wherein the return to the supplier or manufacturer is encouraged for large radioactive sources. The legal situation in Switzerland is described mentioning the demand of minimization of radioactive waste as well as the situation with respect to the interim storage facility at the Paul Scherrer Institute (PSI). Based on this information and on the market situation with a shortage of some medical radionuclides the management of spent sealed sources is provided. The sources are sorted according to their activity in relation to the nuclide-specific A2-value and either recycled as in the case of high active sources or conditioned as in the case for sources with lower activity. The results are presented as comparison between recycled and conditioned activity for three selected nuclides, i.e. Cs-137, Co-60 and Am-241. (author)

  3. Utilization of spent coking plant acid

    SciTech Connect

    Vasil'eva, I.V.; Vasilenko, N.Y.; Mostovaya, V.G.; Tret'yak, N.K.

    1983-01-01

    A feasibility study is described for using spent regenerated sulfuric acid from a coking plant, containing 540-640 g/l H/sub 2/SO/sub 4/, to pickle metals. Results were compared with the performance of a solution of technical sulfuric acid in pickling high-carbon and low-alloy steels. It was found economically feasible to use the spent regenerated acid as the basic pickling solution. The degree of protection of the metal against corrosion is 85%, which can be increased to 98-99% if inhibitors are added to the acid. Only one-fifth as much inhibitor is needed with the regenerated acid as with the technical sulfuric acid.

  4. Spent nuclear fuel project product specification

    SciTech Connect

    Pajunen, A.L.

    1998-01-30

    Product specifications are limits and controls established for each significant parameter that potentially affects safety and/or quality of the Spent Nuclear Fuel (SNF) packaged for transport to dry storage. The product specifications in this document cover the spent fuel packaged in MultiCanister Overpacks (MCOs) to be transported throughout the SNF Project. The SNF includes N Reactor fuel and single-pass reactor fuel. The FRS removes the SNF from the storage canisters, cleans it, and places it into baskets. The MCO loading system places the baskets into MCO/Cask assembly packages. These packages are then transferred to the Cold Vacuum Drying (CVD) Facility. After drying at the CVD Facility, the MCO cask packages are transferred to the Canister Storage Building (CSB), where the MCOs are removed from the casks, staged, inspected, sealed (by welding), and stored until a suitable permanent disposal option is implemented. The key criteria necessary to achieve these goals are documented in this specification.

  5. Spent nuclear fuel project integrated schedule plan

    SciTech Connect

    Squires, K.G.

    1995-03-06

    The Spent Nuclear Fuel Integrated Schedule Plan establishes the organizational responsibilities, rules for developing, maintain and status of the SNF integrated schedule, and an implementation plan for the integrated schedule. The mission of the SNFP on the Hanford site is to provide safe, economic, environmentally sound management of Hanford SNF in a manner which stages it to final disposition. This particularly involves K Basin fuel.

  6. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  7. Spent fuel pool analysis using TRACE code

    SciTech Connect

    Sanchez-Saez, F.; Carlos, S.; Villanueva, J. F.; Martorell, S.

    2012-07-01

    The storage requirements of Spent Fuel Pools have been analyzed with the purpose to increase their rack capacities. In the past, the thermal limits have been mainly evaluated with conservative codes developed for this purpose, although some works can be found in which a best estimate code is used. The use of best estimate codes is interesting as they provide more realistic calculations and they have the capability of analyzing a wide range of transients that could affect the Spent Fuel Pool. Two of the most representative thermal-hydraulic codes are RELAP-5 and TRAC. Nowadays, TRACE code is being developed to make use of the more favorable characteristics of RELAP-5 and TRAC codes. Among the components coded in TRACE that can be used to construct the model, it is interesting to use the VESSEL component, which has the capacity of reproducing three dimensional phenomena. In this work, a thermal-hydraulic model of the Maine Yankee spent fuel pool using the TRACE code is developed. Such model has been used to perform a licensing calculation and the results obtained have been compared with experimental measurements made at the pool, showing a good agreement between the calculations predicted by TRACE and the experimental data. (authors)

  8. Spent Nuclear Fuel Alternative Technology Risk Assessment

    SciTech Connect

    Perella, V.F.

    1999-11-29

    A Research Reactor Spent Nuclear Fuel Task Team (RRTT) was chartered by the Department of Energy (DOE) Office of Spent Fuel Management with the responsibility to recommend a course of action leading to a final technology selection for the interim management and ultimate disposition of the foreign and domestic aluminum-based research reactor spent nuclear fuel (SNF) under DOE''s jurisdiction. The RRTT evaluated eleven potential SNF management technologies and recommended that two technologies, direct co-disposal and an isotopic dilution alternative, either press and dilute or melt and dilute, be developed in parallel. Based upon that recommendation, the Westinghouse Savannah River Company (WSRC) organized the SNF Alternative Technology Program to further develop the direct co-disposal and melt and dilute technologies and provide a WSRC recommendation to DOE for a preferred SNF alternative management technology. A technology risk assessment was conducted as a first step in this recommendation process to determine if either, or both, of the technologies posed significant risks that would make them unsuitable for further development. This report provides the results of that technology risk assessment.

  9. APPLICATIONS OF CURRENT TECHNOLOGY FOR CONTINUOUS MONITORING OF SPENT FUEL

    SciTech Connect

    Drayer, R.

    2013-06-09

    Advancements in technology have opened many opportunities to improve upon the current infrastructure surrounding the nuclear fuel cycle. Embedded devices, very small sensors, and wireless technology can be applied to Security, Safety, and Nonproliferation of Spent Nuclear Fuel. Security, separate of current video monitoring systems, can be improved by integrating current wireless technology with a variety of sensors including motion detection, altimeter, accelerometer, and a tagging system. By continually monitoring these sensors, thresholds can be set to sense deviations from nominal values. Then alarms or notifications can be activated as needed. Safety can be improved in several ways. First, human exposure to ionizing radiation can be reduced by using a wireless sensor package on each spent fuel cask to monitor radiation, temperature, humidity, etc. Since the sensor data is monitored remotely operator stay-time is decreased and distance from the spent fuel increased, so the overall radiation exposure is reduced as compared to visual inspections. The second improvement is the ability to monitor continuously rather than periodically. If changes occur to the material, alarm thresholds could be set and notifications made to provide advanced notice of negative data trends. These sensor packages could also record data to be used for scientific evaluation and studies to improve transportation and storage safety. Nonproliferation can be improved for spent fuel transportation and storage by designing an integrated tag that uses current infrastructure for reporting and in an event; tracking can be accomplished using the Iridium satellite system. This technology is similar to GPS but with higher signal strength and penetration power, but lower accuracy. A sensor package can integrate all or some of the above depending on the transportation and storage requirements and regulations. A sensor package can be developed using off the shelf technology and applying it to each

  10. Chemical Forms and Distribution of Platinum Group Metals and Technetium During Spent Fuel Reprocessing

    SciTech Connect

    Pokhitonov, Y.

    2007-07-01

    Amongst the fission products present in spent nuclear fuel of Nuclear Power Plants there are considerable quantities of platinum group metals (PGMs): ruthenium, rhodium and palladium. At the same time there are considerable amounts of technetium in the spent fuel, the problem of its removal at radiochemical plants being in operation encountering serious difficulties. Increased interest in this radionuclides is due not only to its rather large yield, but to higher mobility in the environment as well. However, the peculiarities of technetium chemistry in nitric acid solutions create certain problems when trying to separate it as a single product in the course of NPP's spent fuel reprocessing. The object of this work was to conduct a comprehensive analysis of platinum group metals and technetium behavior at various stages of spent fuel reprocessing and to seek the decisions which could make it possible to separate its as a single product. The paper will report data on platinum metals (PGM) and technetium distribution in spent fuel reprocessing products. The description of various techniques for palladium recovery from differing in composition radioactive solutions arising from reprocessing is given. (authors)

  11. Radiotoxicity and decay heat power of spent nuclear fuel of VVER type reactors at long-term storage.

    PubMed

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Radiotoxicity and decay heat power of the spent nuclear fuel of VVER-1000 type reactors are calculated during storage time up to 300,000 y. Decay heat power of radioactive waste (radwaste) determines parameters of the heat removal system for the safe storage of spent nuclear fuel. Radiotoxicity determines the radiological hazard of radwaste after its leakage and penetration into the environment. PMID:16381764

  12. Application of spent fuel characterization and leaching studies for validating alteration models

    SciTech Connect

    Quinones, Javier; Iglesias, Eduardo; Rodriguez, Nieves; Cobos Sabate, Joaquin; Martinez-Esparza, Aurora

    2007-07-01

    From the Spanish point of view, one of the key issues related to the HLW performance assessment is knowing and predicting, or modelling, the behaviour of spent fuel under geological repository conditions. Taking into account this objective, several experiments have been performed in order to split and determine the influence of different variables on the final stability of the spent fuel matrix in the geological repository. This paper presents some of the leaching results obtained with spent fuel and chemical analogues (UO{sub 2}, alpha doped-UO{sub 2}, SIMFUEL,) their application to extrapolate the corrosion behaviour for a long period of time and compare with corresponding data obtained using models. This procedure allows pointing out some of the uncertainties whose minimization is necessary to improve the models useful for performance assessment studies. (authors)

  13. Comparative economics for DUCRETE spent fuel storage cask handling, transportation, and capital requirements

    SciTech Connect

    Powell, F.P.

    1995-04-01

    This report summarizes economic differences between a DUCRETE spent nuclear fuel storage cask and a conventional concrete storage cask in the areas of handling, transportation, and capital requirements. The DUCRETE cask is under evaluation as a new technology that could substantially reduce the overall costs of spent fuel and depleted U disposal. DUCRETE incorporates depleted U in a Portland cement mixture and functions as the cask`s primary radiation barrier. The cask system design includes insertion of the US DOE Multi-Purpose Canister inside the DUCRETE cask. The economic comparison is from the time a cask is loaded in a spent fuel pool until it is placed in the repository and includes the utility and overall US system perspectives.

  14. DOE-owned spent nuclear fuel program plan

    SciTech Connect

    1995-11-01

    The Department of Energy (DOE) has produced spent nuclear fuel (SNF) for many years as part of its various missions and programs. The historical process for managing this SNF was to reprocess it whereby valuable material such as uranium or plutonium was chemically separated from the wastes. These fuels were not intended for long-term storage. As the need for uranium and plutonium decreased, it became necessary to store the SNF for extended lengths of time. This necessity resulted from a 1992 DOE decision to discontinue reprocessing SNF to recover strategic materials (although limited processing of SNF to meet repository acceptance criteria remains under consideration, no plutonium or uranium extraction for other uses is planned). Both the facilities used for storage, and the fuel itself, began experiencing aging from this extended storage. New efforts are now necessary to assure suitable fuel and facility management until long-term decisions for spent fuel disposition are made and implemented. The Program Plan consists of 14 sections as follows: Sections 2--6 describe objectives, management, the work plan, the work breakdown structure, and the responsibility assignment matrix. Sections 7--9 describe the program summary schedules, site logic diagram, SNF Program resource and support requirements. Sections 10--14 present various supplemental management requirements and quality assurance guidelines.

  15. X-ray fluorescence analysis of spent reactor fuel solutions

    SciTech Connect

    Berdikov, V.V.; Iokhin, B.S.

    1987-01-01

    The present work examines the possibility of laboratory analytic control by means of a crystal-free x-ray fluorescence analysis (XRFA) installation specifically designed for this purpose with a prior selection of fluorescent emissions by energy. Monitoring by fluorescent emissions from selenium positioned in the installation along with a metering cuvette allows the exclusion of errors associated with the instability of the x-ray tube beam and the effects of the superpositioning of impulses and of dead time. Tests were made on the possibility of using hard standards, consisting of pellets of uranium-aluminum alloy in a fluoroplastic casing. Some characteristics are shown of the crystal-free x-ray fluorescent method of determining uranium concentration in the technological products from reprocessing spent fuel from a water-moderated, water-cooled reactor. The determination of the uranium content in diluted incoming solutions in the reprocessing of spent fuel from such a reactor was also tested by comparison with the results of the method of isotopic dilution concluded using mass-spectrometry.

  16. Predicting the potential for arsenic contamination from spent gold ore

    SciTech Connect

    Peterson, E.R.; Luce, R.W.; Jenkins, C.B.

    1993-12-01

    Experiments were conducted on pilot study tuffaceous ore and native soils to predict arsenic leachability and subsequent attenuation from a proposed spent ore pile at an Idaho gold mine. The experiments were patterned after the graded serial batch extraction tests developed by Houle and Long and were designed to mimic the leachate movement through time and space conditions not attainable by column tests. Each extraction sequence involved consecutive contact with three batches of spent ore followed by three batches of soil. Four different samples of soil collected from the proposed mining site were tested in this manner. Solution aliquots were taken from each batch, filtered, and analyzed for arsenic and pH. Four extraction sequences were run for each soil type at increasing liquid-to-solid ratios to simulate increasing durations of leaching and attenuation. A total of 16 extraction sequences were conducted. Analytical results of the solution aliquots showed an increase in arsenic concentrations on contact with successive batches of ore, but a decrease in concentration after contact with soil batches. For the conditions simulated, adsorption and precipitation by natural soils would prevent contamination of ground and surface waters. The results are consistent with the known aqueous geochemistry of arsenic.

  17. Status of DOE efforts to renew acceptance of foreign research reactor spent nuclear fuel

    SciTech Connect

    Head, C.R.

    1997-08-01

    This presentation summarizes the efforts being made by the Department of Energy to renew acceptance of spent nuclear fuel shipments from foreign research reactors. The author reviews the actions undertaken in this process in a fairly chronological manner, through the present time, as well as the development of an environmental impact statement to support the proposed actions.

  18. Evaluation of improvement potential for spent fuel cask handling

    SciTech Connect

    Franklin, A.L.

    1981-02-01

    This report describes the quantitative analysis of opportunities to improve the loading/unloading operations for spent fuel shipping casks. The improvement potential is defined as a reduction in the time for completion or worker exposure for the complete handling operations. Two casks have been chosen as representative of presently available shipping casks. These are the NAC-1/NFS-4 legal weight truck cask and the IF-300 rail cask. The handling operations for each of these casks are broken down into a series of sequential steps. The time for completion and worker exposure is described by a probability density function for each step. These step descriptions are then combined to form a base case description of the total loading/unloading operation. Potential improvement opportunities are evaluated by modifying the appropriate probability density function descriptors then recombining the steps to form a probabilistic description of the modified operation.

  19. Nitrogen transformations during co-composting of herbal residues, spent mushrooms, and sludge*

    PubMed Central

    Wu, Dong-lei; Liu, Ping; Luo, Yan-zhang; Tian, Guang-ming; Mahmood, Qaisar

    2010-01-01

    Sewage sludge composting is an important environmental measure. The reduction of nitrogen loss is a critical aim of compost maturation, and the addition of spent mushrooms (SMs) and herbal residues (HRs) may be helpful. To evaluate the nitrogen transformations during co-composting of sewage sludge, SMs, and HRs, windrows were constructed in a residual processing plant. Dewatered sewage sludge and sawdust were mixed with SMs and HRs at two proportions on a fresh weight basis, 3:1:1 (sewage sludge:sawdust:SMs or HRs) and 3:1:2 (sewage sludge:sawdust:SMs or HRs). The mixture was then composted for 40 d. Changes in the physicochemical characteristic of sewage sludge during composting were recorded and analyzed. Addition of SMs and HRs accelerated the temperature rise, mediating a quicker composting maturation time compared to control. The addition also resulted in lower nitrogen losses and higher nitrate nitrogen levels in the compost products. Among the windrows, SM and HR addition improved the nitrogen status. The total nitrogen (TN) and nitrogen losses for SM and HR treatments ranged from 22.45 to 24.99 g/kg and from 10.2% to 22.4% over the control values (18.66–21.57 g/kg and 40.5%–64.2%, respectively). The pile with the highest proportion of SMs (3:1:2 (sewage sludge:sawdust:SMs)) had the highest TN level and the lowest nitrogen loss. The germination index (GI) values for all samples at maturity were above 80%, demonstrating optimal maturity. The addition of SMs and HRs augments sewage composting. PMID:20593514

  20. Effectiveness of cement-based systems for stabilization and solidification of spent pot liner inorganic fraction.

    PubMed

    Silveira, B I; Dantas, A E M; Blasques, J E M; Santos, R K P

    2003-03-17

    Approximately 7000 t of spent pot liner (SPL) wastes are generated annually from activities associated with Alumi;nio Brasileiro S.A. (ALBRAS) plant located at Barcarena, Pará state, Brazil. The inorganic fraction of SPL contains high level of toxic compounds like cyanide and fluoride; its safe disposal has been the subject of serious discussions in Brazil. This study evaluated the option of a cement-based stabilization/solidification system as an effective means for safe disposal of SPL inorganic fraction in the field. The studies were carried out with concrete hexagonal blocks manufactured with a constant mass of 10% (w/w) of waste, 20% (w/w) of cement, and varied percentages of water, coarse aggregate, sand, and additives. The concrete matrices porosity and compressive strength were controlled by using microsilica (MS) and superplaticizer (SP). The results showed an average pH values for the SPL inorganic fraction and fragmented blocks of 10.2 and 11.1, respectively. Mixing the waste with concrete ingredients the solidification/stabilization effectiveness for the leachable cyanides and fluorides were of 59.33 and 57.95%, respectively. The results showed that the water/cement (W/C) ratio reduction through superplasticizer addition improved the compressive strength and the required value of 35 MPa was reached with blocks manufactured with 10 and 15% (weight of cement) of microsilica, after 28 days of curing time. PMID:12628786

  1. A calcite permeable reactive barrier for the remediation of Fluoride from spent potliner (SPL) contaminated groundwater

    NASA Astrophysics Data System (ADS)

    Turner, Brett D.; Binning, Philip J.; Sloan, Scott W.

    2008-01-01

    The use of calcite (CaCO 3) as a substrate for a permeable reactive barrier (PRB) for removing fluoride from contaminated groundwater is proposed and is illustrated by application to groundwater contaminated by spent potliner leachate (SPL), a waste derived from the aluminium smelting process. The paper focuses on two issues in the implementation of calcite permeable reactive barriers for remediating fluoride contaminated water: the impact of the groundwater chemical matrix and CO 2 addition on fluoride removal. Column tests comparing pure NaF solutions, synthetic SPL solutions, and actual SPL leachate indicate that the complex chemical matrix of the SPL leachate can impact fluoride removal significantly. For SPL contaminant mixtures, fluoride removal is initially less than expected from idealized, pure, solutions. However, with time, the effect of other contaminants on fluoride removal diminishes. Column tests also show that pH control is important for optimizing fluoride removal with the mass removed increasing with decreasing pH. Barrier pH can be regulated by CO 2 addition with the point of injection being critical for optimising the remediation performance. Experimental and model results show that approximately 99% of 2300 mg/L fluoride can be removed when CO 2 is injected directly into the barrier. This can be compared to approximately 30-50% removal when the influent solution is equilibrated with atmospheric CO 2 before contact with calcite.

  2. A calcite permeable reactive barrier for the remediation of Fluoride from spent potliner (SPL) contaminated groundwater.

    PubMed

    Turner, Brett D; Binning, Philip J; Sloan, Scott W

    2008-01-28

    The use of calcite (CaCO3) as a substrate for a permeable reactive barrier (PRB) for removing fluoride from contaminated groundwater is proposed and is illustrated by application to groundwater contaminated by spent potliner leachate (SPL), a waste derived from the aluminium smelting process. The paper focuses on two issues in the implementation of calcite permeable reactive barriers for remediating fluoride contaminated water: the impact of the groundwater chemical matrix and CO2 addition on fluoride removal. Column tests comparing pure NaF solutions, synthetic SPL solutions, and actual SPL leachate indicate that the complex chemical matrix of the SPL leachate can impact fluoride removal significantly. For SPL contaminant mixtures, fluoride removal is initially less than expected from idealized, pure, solutions. However, with time, the effect of other contaminants on fluoride removal diminishes. Column tests also show that pH control is important for optimizing fluoride removal with the mass removed increasing with decreasing pH. Barrier pH can be regulated by CO2 addition with the point of injection being critical for optimising the remediation performance. Experimental and model results show that approximately 99% of 2300 mg/L fluoride can be removed when CO2 is injected directly into the barrier. This can be compared to approximately 30-50% removal when the influent solution is equilibrated with atmospheric CO2 before contact with calcite. PMID:17913284

  3. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  4. Regulatory Perspective on Potential Fuel Reconfiguration and Its Implication to High Burnup Spent Fuel Storage and Transportation - 13042

    SciTech Connect

    Li, Zhian; Rahimi, Meraj; Tang, David; Aissa, Mourad; Flaganan, Michelle; Wagner, John C.

    2013-07-01

    The recent experiments conducted by Argonne National Laboratory on high burnup fuel cladding material property show that the ductile to brittle transition temperature of high burnup fuel cladding is dependent on: (1) cladding material, (2) irradiation conditions, and (3) drying-storage histories (stress at maximum temperature) [1]. The experiment results also show that the ductile to brittle temperature increases as the fuel burnup increases. These results indicate that the current knowledge in cladding material property is insufficient to determine the structural performance of the cladding of high burnup fuel after it has been stored in a dry cask storage system for some time. The uncertainties in material property and the elevated ductile to brittle transition temperature impose a challenge to the storage cask and transportation packaging designs because the cask designs may not be able to rely on the structural integrity of the fuel assembly for control of fissile material, radiation source, and decay heat source distributions. The fuel may reconfigure during further storage and/or the subsequent transportation conditions. In addition, the fraction of radioactive materials available for release from spent fuel under normal condition of storage and transport may also change. The spent fuel storage and/or transportation packaging vendors, spent fuel shippers, and the regulator may need to consider this possible fuel reconfiguration and its impact on the packages' ability to meet the safety requirements of Part 72 and Part 71 of Title 10 of the Code of Federal Regulations. The United States Nuclear Regulatory Commission (NRC) is working with the scientists at Oak Ridge National Laboratory (ORNL) to assess the impact of fuel reconfiguration on the safety of the dry storage systems and transportation packages. The NRC Division of Spent Fuel Storage and Transportation has formed a task force to work on the safety and regulatory concerns in relevance to high burnup

  5. Comparative analysis of isotopic composition of spent fuel from Takahama-3 PWR PIE database using TRIPOLI-PEPIN code

    SciTech Connect

    Lee, Y. K.

    2006-07-01

    Evaluation of isotopic composition of spent nuclear fuel is essential for reactor physics and fuel cycle back-end applications. A TRIPOLI-PEPIN coupled depletion code, TR4PEP, has been developed to meet these requirements. It combines the continuous-energy Monte Carlo transport code, TRIPOLI4.3 [1] and the point depletion code, PEPIN-2 [2], to perform the burnup dependent material data calculation. The depletion calculation flow of TR4PEP code has been presented on a previous study. Its application on PWR UO{sub 2} and MOX spent fuel has been validated against several international numerical benchmarks. Compared to industry standard deterministic cell codes and other Monte Carlo based depletion codes, TR4PEP deep-burn depletion calculations have shown satisfactory results. [3] In addition to the numerical benchmarks, the analysis of available post irradiation examination (PIE) results by TR4PEP is also important The PIE results at fuel assembly level are accessible only from spent fuel reprocessing plant and these data are not easy to use for code validation due to the dissolution of several assemblies in the same time. The PIE results at fuel pellet level depend not only on the method for the isotopic measurements but also on the irradiation environment and history. A free access PIE database on isotopic composition of spent nuclear fuel is obtainable from OECD/NEA. [4] Both PWR and BWR PIE data at fuel pellet level are taken into account in this database but the only 17 x 17 type PWR fuel available in this database is from Takahama-3 PIE results. To validate TR4PEP with Takahama-3 PIE results, two irradiated UO{sub 2} samples, SF95-4 from fuel assembly NT3G23 and SF97-5 from NT3G24, are considered in this study. Both samples have an initial {sup 235}U enrichment of 4.11 wt% and their burnup are respectively 36.69 and 47.03 GWd/t. Comparative analysis of isotopic composition from SF95-4 and SF97-5 including 19 actinides from {sup 234}U to {sup 247}Cm and 18

  6. Recovery of natural antioxidants from spent coffee grounds.

    PubMed

    Panusa, Alessia; Zuorro, Antonio; Lavecchia, Roberto; Marrosu, Giancarlo; Petrucci, Rita

    2013-05-01

    Spent coffee grounds (SCG) were extracted with an environmentally friendly procedure and analyzed to evaluate the recovery of relevant natural antioxidants for use as nutritional supplements, foods, or cosmetic additives. SCG were characterized in terms of their total phenolic content by the Folin-Ciocalteu procedure and antioxidant activity by the DPPH scavenging assay. Flavonoid content was also determined by a colorimetric assay. The total phenolic content was strongly correlated with the DPPH scavenging activity, suggesting that phenolic compounds are mainly responsible for the antioxidant activity of SCG. An UHPLC-PDA-TOF-MS system was used to separate, identify, and quantify phenolic and nonphenolic compounds in the SCG extracts. Important amounts of chlorogenic acids (CGA) and related compounds as well as caffeine (CAF) evidenced the high potential of SCG, a waste material that is widely available in the world, as a source of natural phenolic antioxidants. PMID:23577588

  7. Fracture mapping at the Spent Fuel Test-Climax

    SciTech Connect

    Wilder, D.G.; Yow, J.L. Jr.

    1981-05-01

    Mapping of geologic discontinuities has been done in several phases at the Spent Fuel Test-Climax (SFT-C) in the granitic Climax stock at the Nevada Test Site. Mapping was carried out in the tail drift, access drift, canister drift, heater drifts, instrumentation alcove, and receiving room. The fractures mapped as intersecting a horizontal datum in the canister and heater drifts are shown on one figure. Fracture sketch maps have been compiled as additional figures. Geologic mapping efforts were scheduled around and significantly impacted by the excavation and construction schedules. Several people were involved in the mapping, and over 2500 geologic discontinuities were mapped, including joints, shears, and faults. Some variance between individuals` mapping efforts was noticed, and the effects of various magnetic influences upon a compass were examined. The examination of compass errors improved the credibility of the data. The compass analysis work is explained in Appendix A. Analysis of the fracture data will be presented in a future report.

  8. SPENT FUEL MANAGEMENT AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Vormelker, P; Robert Sindelar, R; Richard Deible, R

    2007-11-03

    Spent nuclear fuels are received from reactor sites around the world and are being stored in the L-Basin at the Savannah River Site (SRS) in Aiken, South Carolina. The predominant fuel types are research reactor fuel with aluminum-alloy cladding and aluminum-based fuel. Other fuel materials include stainless steel and Zircaloy cladding with uranium oxide fuel. Chemistry control and corrosion surveillance programs have been established and upgraded since the early 1990's to minimize corrosion degradation of the aluminum cladding materials, so as to maintain fuel integrity and minimize personnel exposure from radioactivity in the basin water. Recent activities have been initiated to support additional decades of wet storage which include fuel inspection and corrosion testing to evaluate the effects of specific water impurity species on corrosion attack.

  9. Compton suppressed LaBr3 detection system for use in nondestructive spent fuel assay

    NASA Astrophysics Data System (ADS)

    Bender, S.; Heidrich, B.; Ünlü, K.

    2015-06-01

    Current methods for safeguarding and accounting for spent nuclear fuel in reprocessing facilities are extremely resource and time intensive. The incorporation of autonomous passive gamma-ray detectors into the procedure could make the process significantly less burdensome. In measured gamma-ray spectra from spent nuclear fuel, the Compton continuum from dominant fission product photopeaks obscure the lower energy lines from other isotopes. The application of Compton suppression to gamma-ray measurements of spent fuel may reduce this effect and allow other less intense, lower energy peaks to be detected, potentially improving the accuracy of multivariate analysis algorithms. Compton suppressed spectroscopic measurements of spent nuclear fuel using HPGe, LaBr3, and NaI(Tl) primary detectors were performed. Irradiated fuel was measured in two configurations: as intact fuel elements viewed through a collimator and as feed solutions in a laboratory to simulate the measurement of a dissolved process stream. These two configurations allowed the direct assessment and quantification of the differences in measured gamma-ray spectra from the application of Compton suppression. In the first configuration, several irradiated fuel elements of varying cooling times from the Penn State Breazeale Reactor spent fuel inventory were measured using the three collimated Compton suppression systems. In the second geometry, Compton suppressed measurements of two samples of Approved Test Material commercial fuel elements were recorded inside the guard detector annulus to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Compton suppression was found to improve measured gamma-ray spectra of spent fuel for multivariate analysis by notably lowering the Compton continuum from dominant photopeaks such as 137Cs and 140La, due to scattered interactions in the detector, which allowed more spectral features to be resolved. There was a

  10. OECD NEA Benchmark Database of Spent Nuclear Fuel Isotopic Compositions for World Reactor Designs

    SciTech Connect

    Gauld, Ian C; Sly, Nicholas C; Michel-Sendis, Franco

    2014-01-01

    Experimental data on the isotopic concentrations in irradiated nuclear fuel represent one of the primary methods for validating computational methods and nuclear data used for reactor and spent fuel depletion simulations that support nuclear fuel cycle safety and safeguards programs. Measurement data have previously not been available to users in a centralized or searchable format, and the majority of accessible information has been, for the most part, limited to light-water-reactor designs. This paper describes a recent initiative to compile spent fuel benchmark data for additional reactor designs used throughout the world that can be used to validate computer model simulations that support nuclear energy and nuclear safeguards missions. Experimental benchmark data have been expanded to include VVER-440, VVER-1000, RBMK, graphite moderated MAGNOX, gas cooled AGR, and several heavy-water moderated CANDU reactor designs. Additional experimental data for pressurized light water and boiling water reactor fuels has also been compiled for modern assembly designs and more extensive isotopic measurements. These data are being compiled and uploaded to a recently revised structured and searchable database, SFCOMPO, to provide the nuclear analysis community with a centrally-accessible resource of spent fuel compositions that can be used to benchmark computer codes, models, and nuclear data. The current version of SFCOMPO contains data for eight reactor designs, 20 fuel assembly designs, more than 550 spent fuel samples, and measured isotopic data for about 80 nuclides.

  11. Biodegradation of complex hydrocarbons in spent engine oil by novel bacterial consortium isolated from deep sea sediment.

    PubMed

    Ganesh Kumar, A; Vijayakumar, Lakshmi; Joshi, Gajendra; Magesh Peter, D; Dharani, G; Kirubagaran, R

    2014-10-01

    Complex hydrocarbon and aromatic compounds degrading marine bacterial strains were isolated from deep sea sediment after enrichment on spent engine (SE) oil. Phenotypic characterization and phylogenetic analysis of 16S rRNA gene sequences showed the isolates were related to members of the Pseudoalteromonas sp., Ruegeria sp., Exiguobacterium sp. and Acinetobacter sp. Biodegradation using 1% (v/v) SE oil with individual and mixed strains showed the efficacy of SE oil utilization within a short retention time. The addition of non-ionic surfactant 0.05% (v/v) Tween 80 as emulsifying agent enhanced the solubility of hydrocarbons and renders them more accessible for biodegradation. The degradation of several compounds and the metabolites formed during the microbial oxidation process were confirmed by Fourier transform infrared spectroscopy and Gas chromatography-mass spectrometry analyses. The potential of this consortium to biodegrade SE oil with and without emulsifying agent provides possible application in bioremediation of oil contaminated marine environment. PMID:25171211

  12. SOURCE OF BURNUP VALUES FOR COMMERCIAL SPENT NUCLEAR FUEL ASSEMBLIES

    SciTech Connect

    BSC

    2004-12-01

    Waste packages are loaded with commercial spent nuclear fuel (SNF) that satisfies the minimum burnup requirements of a criticality loading curve. The burnup value assigned by the originating nuclear utility to each SNF assembly (assigned burnup) is used to load waste packages in compliance with a criticality loading curve. The burnup provided by a nuclear utility has uncertainties, so conservative calculation methods are used to characterize those uncertainties for incorporation into the criticality loading curves. Procedural safety controls ensure that the correct assembly is loaded into each waste package to prevent a misload that could create a condition affecting the safety margins. Probabilistic analyses show that procedural safety controls can minimize the chance of a misload but can not completely eliminate the possibility. Physical measurements of burnup with instrumentation in the surface facility are not necessary due to the conservative calculation methods used to produce the criticality loading curves. The reactor records assigned burnup of a commercial SNF assembly contains about two percent uncertainty, which is increased to five-percent to ensure conservatism. This five-percent uncertainty is accommodated by adjusting the criticality loading curve. Also, the record keeping methods of nuclear utilities are not uniform and the level of detail required by the NRC has varied over the last several decades. Thus, some SNF assemblies may have assigned burnups that are averages for a batch of assemblies with similar characteristics. Utilities typically have access to more detailed core-follow records that allow the batch average burnup to be changed to an assembly specific burnup. Alternatively, an additional safety margin is incorporated into the criticality loading curve to accommodate SNF assemblies with batch average burnups or greater uncertainties due to the methodology used by the nuclear utility. The utility records provide the assembly identifier

  13. CO2 Sequestration within Spent Oil Shale

    NASA Astrophysics Data System (ADS)

    Foster, H.; Worrall, F.; Gluyas, J.; Morgan, C.; Fraser, J.

    2013-12-01

    Worldwide deposits of oil shales are thought to represent ~3 trillion barrels of oil. Jordanian oil shale deposits are extensive and of high quality, and could represent 100 billion barrels of oil, leading to much interest and activity in the development of these deposits. The exploitation of oil shales has raised a number of environmental concerns including: land use, waste disposal, water consumption, and greenhouse gas emissions. The dry retorting of oil shales can overcome a number of the environmental impacts, but this leaves concerns over management of spent oil shale and CO2 production. In this study we propose that the spent oil shale can be used to sequester CO2 from the retorting process. Here we show that by conducting experiments using high pressure reaction facilities, we can achieve successful carbonation of spent oil shale. High pressure reactor facilities in the Department of Earth Sciences, Durham University, are capable of reacting solids with a range of fluids up to 15 MPa and 350°C, being specially designed for research with supercritical fluids. Jordanian spent oil shale was reacted with high pressure CO2 in order to assess whether there is potential for sequestration. Fresh and reacted materials were then examined by: Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Thermogravimetric Analysis (TGA), X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) methods. Jordanian spent oil shale was found to sequester up to 5.8 wt % CO2, on reacting under supercritical conditions, which is 90% of the theoretical carbonation. Jordanian spent oil shale is composed of a large proportion of CaCO3, which on retorting decomposes, forming CaSO4 and Ca-oxides which are the focus of carbonation reactions. A factorially designed experiment was used to test different factors on the extent of carbonation, including: pressure; temperature; duration; and the water content. Analysis of Variance (ANOVA) techniques were then used to determine the significance of

  14. Appliance Ownership and Household Work Time.

    ERIC Educational Resources Information Center

    Lovingood, Rebecca P.; McCullough, Jane L.

    1986-01-01

    Data from 2,100 two-parent, two-child households were analyzed to determine the relationships of demographic variables, ownership of 11 appliances, and time spent in four categories of household tasks. Little evidence was found that appliance ownership is related to less time being spent in household tasks. (Author/CT)

  15. Use of alumina spent catalyst and RFCC wastes from petroleum refinery to substitute bauxite in the preparation of Portland clinker.

    PubMed

    Al-Dhamri, Hilal; Melghit, Khaled

    2010-07-15

    Bauxite was substituted with spent catalysts for clinker preparation. Three different clinkers were prepared: one with bauxite as a reference, one with spent alumina catalyst and another with reduced fluid cracking catalyst. Powder X-ray diffraction technique, thermal analysis and scanning electron microscope were used to characterize each clinker sample. Rietveld refinement shows that, in all clinkers prepared, alite was formed with hexagonal lattice and monoclinic belite has higher unit cell volume compared to the known beta-Ca(2)SiO(4). The physical and mechanical properties (specific area, setting time, heat of hydration, soundness and compressive strength) of the cement samples were studied. The results show that substitution of bauxite by spent catalysts gave close results in terms of chemical composition, physical and mechanical properties of the Portland clinker. Also it shows the spent catalysts do not affect the quality of the prepared cement. PMID:20395040

  16. Spent fuel management status perspectives in Korea

    SciTech Connect

    Park, H.S.; Lee, J.S.; Kim, B.T. )

    1992-01-01

    Concomitant with steadily increasing nuclear power program in Korea, a national radioactive waste management program has been in initial implementation stage for several years. In late 1990, however, a serious confrontation was witnessed at Anmyon area where residents expressed strong opposition against any possibility to consider that site as a potential candidate for waste disposal by the Authority. As far as spent fuel management is concerned, an interim storage policy was adopted by Korean Atomic Energy Commission. A decision to build a centralized wet storage facility was made followed by a conceptual design. Due to the incident at Anmyon site, the public has became more concerned about radioactive wastes management. Parallel efforts are being made to ameliorate public acceptance in regard to radioactive waste management and in particular to spent fuel management. There are substantial uncertainties, however, whether any site could be found given that precarious mood has been prevailing against radioactive wastes throughout the world. In the meantime waiting for successful siting, various research and development for future perspectives are in order. Of particular importance in such endeavor is to provide technological impetus for future perspectives as well as public acceptance through safety demonstrations of certain viable technology alternatives. The dry storage option, for instance, is acclaimed for intrinsic safety and lower cost as prospective alternative. Combined with rod consolidation, dry storage technologies which have not extensively applied in the past, could be considered as a technological basis for longer term management of spent fuel. Conscious of such global trend, some appropriate programs in preparation for such perspectives have been launched by KAERI.

  17. Electrometallurgical treatment of oxide spent fuel.

    SciTech Connect

    Karell, E. J.

    1999-06-08

    The Department of Energy (DOE) inventory of spent nuclear fuel contains a wide variety of oxide fuel types that may be unsuitable for direct repository disposal in their current form. The molten-salt electrometallurgical treatment technique developed by Argonne National Laboratory (ANL) has the potential to simplify preparing and qualifying these fuels for disposal by converting them into three uniform product streams: uranium metal, a metal waste form, and a ceramic waste form. This paper describes the major steps in the electrometallurgical treatment process for oxide fuels and provides the results of recent experiments performed to develop and scale up the process.

  18. Surrogate Spent Nuclear Fuel Vibration Integrity Investigation

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Bevard, Bruce Balkcom; Howard, Rob L

    2014-01-01

    Transportation packages for spent nuclear fuel (SNF) must meet safety requirements under normal and accident conditions as specified by federal regulations. During transportation, SNF experiences unique conditions and challenges to cladding integrity due to the vibrational and impact loading encountered during road or rail shipment. ORNL has been developing testing capabilities that can be used to improve our understanding of the impacts of vibration loading on SNF integrity, especially for high burn-up SNF in normal transportation operation conditions. This information can be used to meet nuclear industry and U.S. Nuclear Regulatory Commission needs in the area of safety of SNF storage and transportation operations.

  19. Spent fuel management fee methodology and computer code user's manual.

    SciTech Connect

    Engel, R.L.; White, M.K.

    1982-01-01

    The methodology and computer model described here were developed to analyze the cash flows for the federal government taking title to and managing spent nuclear fuel. The methodology has been used by the US Department of Energy (DOE) to estimate the spent fuel disposal fee that will provide full cost recovery. Although the methodology was designed to analyze interim storage followed by spent fuel disposal, it could be used to calculate a fee for reprocessing spent fuel and disposing of the waste. The methodology consists of two phases. The first phase estimates government expenditures for spent fuel management. The second phase determines the fees that will result in revenues such that the government attains full cost recovery assuming various revenue collection philosophies. These two phases are discussed in detail in subsequent sections of this report. Each of the two phases constitute a computer module, called SPADE (SPent fuel Analysis and Disposal Economics) and FEAN (FEe ANalysis), respectively.

  20. Investigation of the condition of spent-fuel pool components

    SciTech Connect

    Kustas, F.M.; Bates, S.O.; Opitz, B.E.; Johnson, A.B. Jr.; Perez, J.M. Jr.; Farnsworth, R.K.

    1981-09-01

    It is currently projected that spent nuclear fuel, which is discharged from the reactor and then stored in water pools, may remain in those pools for several decades. Other studies have addressed the expected integrity of the spent fuel during extended water storage; this study assesses the integrity of metallic spent fuel pool components. Results from metallurgical examinations of specimens taken from stainless steel and aluminum components exposed in spent fuel pools are presented. Licensee Event Reports (LERs) relating to problems with spent fuel components were assessed and are summarized to define the types of operational problems that have occurred. The major conclusions of this study are: aluminum and stainless steel spent fuel pool components have a good history of performance in both deionized and borated water pools. Although some operational problems involving pool components have occurred, these problems have had minimal impacts.

  1. Why More 'Quality Time' Is Not on the Top of Children's Lists: The 'Qualities of Time' for Children.

    ERIC Educational Resources Information Center

    Christensen, Pia Haudrup

    2002-01-01

    Presents research on children's understandings and use of time; findings suggest that time spent with family cannot be seen as separate from time spent with friends, at school, and on their own. Argues that the quality/quantity time conundrum needs replacing by fuller and more representative accounts of the varied aspects of time that matter for…

  2. Postulated licensing schedule for an independent spent fuel storage installation

    SciTech Connect

    Ludwick, J.D.

    1982-11-01

    A review of licensing requirements, processes, and anticipated actions for independent spent fuel storage installations (ISFSIs) was conducted in order to develop an estimated schedule and sequence of events for licensing a new ISFSI. This estimate will be useful to potential ISFSI owners in planning for the licensing of their facilities. It is concluded that, although many uncertainties exist with respect to such things as legal appeals, about 29 months are estimated to elapse between license application and license issuance for an ISFSI. This estimate is in reasonable agreement with a previous time estimate for licensing an ISFSI, and, taking into account the special circumstances involved, with the actual licensing schedule for the GE-Morris ISFSI. However, individual portions of the licensing schedule from each case studied sometimes vary significantly.

  3. Climax spent fuel dosimetry. Progress report, September 1980-September 1981

    SciTech Connect

    Quam, W.; DeVore, T.

    1981-10-01

    This progress report covers dosimetry work at the Climax Spent Fuel Test Facility up to September 1981. During this time the gamma calibrations were completed, the temperature-induced fading study was completed, the first set of exposed dosimeters was retrieved, and the second set of dosimeters was placed in the field. These were installed in stainless steel tubes located on the inside wall of five canister emplacement holes (0.61 m in diameter), numbers 1, 3, 4, 7, and 11. Hole 3 also had dosimeters in similar stainless steel tubes placed at radii of 0.51 and 0.66 m from the canister centerline. Data obtained from the first exposure (about 270 days in duration) are reported. Significant neutron exposures were measured; in some cases they were sufficiently high that neutron spectra could be calculated.

  4. Biosorption of Azo dyes by spent Rhizopus arrhizus biomass

    NASA Astrophysics Data System (ADS)

    Salvi, Neeta A.; Chattopadhyay, S.

    2016-05-01

    In the present study, spent Rhizopus arrhizus biomass was used for the removal of six azo dyes from aqueous solutions. The dye removal capacity of the biomass was evaluated by conducting batch tests as a function of contact time, biomass dosage, pH and initial dye concentrations. The pseudo-second-order kinetic model fitted well with the experimental data with correlation coefficients greater than 0.999, suggesting that chemisorptions might be the rate limiting step. The equilibrium sorption data showed good fit to the Langmuir isotherm model. Among the six dyes tested, the maximum monolayer adsorption capacity for fast red A and metanil yellow was found to be 108.8 and 128.5 mg/g, respectively. These encouraging results suggest that dead Rhizopus arrhizus biomass could be a potential biomaterial for the removal of azo dyes from aqueous dye solution.

  5. Air Transport of Spent Nuclear Fuel (SNF) Assemblies

    SciTech Connect

    Haire, M.J.; Moses, S.D.; Shapovalov, V.I.; Morenko, A.

    2007-07-01

    Sometimes the only feasible means of shipping research reactor spent nuclear fuel (SNF) among countries is via air transport because of location or political conditions. The International Atomic Energy Agency (IAEA) has established a regulatory framework to certify air transport Type C casks. However, no such cask has been designed, built, tested, and certified. In lieu of an air transport cask, research reactor SNF has been transported using a Type B cask under an exemption with special arrangements for administrative and security controls. This work indicates that it may be feasible to transport commercial power reactor SNF assemblies via air, and that the cost is only about three times that of shipping it by railway. Optimization (i.e., reduction) of this cost factor has yet to be done. (authors)

  6. Tackifier for addition polyimides

    NASA Technical Reports Server (NTRS)

    Butler, J. M.; St.clair, T. L.

    1980-01-01

    A modification to the addition polyimide, LaRC-160, was prepared to improve tack and drape and increase prepeg out-time. The essentially solventless, high viscosity laminating resin is synthesized from low cost liquid monomers. The modified version takes advantage of a reactive, liquid plasticizer which is used in place of solvent and helps solve a major problem of maintaining good prepeg tack and drape, or the ability of the prepeg to adhere to adjacent plies and conform to a desired shape during the lay up process. This alternate solventless approach allows both longer life of the polymer prepeg and the processing of low void laminates. This approach appears to be applicable to all addition polyimide systems.

  7. Radiological characterization of spent control rod assemblies

    SciTech Connect

    Lepel, E.A.; Robertson, D.E.; Thomas, C.W.; Pratt, S.L.; Haggard, D.L.

    1995-10-01

    This document represents the final report of an ongoing study to provide radiological characterizations, classifications, and assessments in support of the decommissioning of nuclear power stations. This report describes the results of non-destructive and laboratory radionuclide measurements, as well as waste classification assessments, of BWR and PWR spent control rod assemblies. The radionuclide inventories of these spent control rods were determined by three separate methodologies, including (1) direct assay techniques, (2) calculational techniques, and (3) by sampling and laboratory radiochemical analyses. For the BWR control rod blade (CRB) and PWR burnable poison rod assembly (BPRA), {sup 60}Co and {sup 63}Ni, present in the stainless steel cladding, were the most abundant neutron activation products. The most abundant radionuclide in the PWR rod cluster control assembly (RCCA) was {sup 108m}Ag (130 yr halflife) produced in the Ag-In-Cd alloy used as the neutron poison. This radionuclide will be the dominant contributor to the gamma dose rate for many hundreds of years. The results of the direct assay methods agree very well ({+-}10%) with the sampling/radiochemical measurements. The results of the calculational methods agreed fairly well with the empirical measurements for the BPRA, but often varied by a factor of 5 to 10 for the CRB and the RCCA assemblies. If concentration averaging and encapsulation, as allowed by 10CFR61.55, is performed, then each of the entire control assemblies would be classified as Class C low-level radioactive waste.

  8. Systems impacts of spent fuel disassembly alternatives

    SciTech Connect

    Not Available

    1984-07-01

    Three studies were completed to evaluate four alternatives to the disposal of intact spent fuel assemblies in a geologic repository. A preferred spent fuel waste form for disposal was recommended on consideration of (1) package design and fuel/package interaction, (2) long-term, in-repository performance of the waste form, and (3) overall process performance and costs for packaging, handling, and emplacement. The four basic alternative waste forms considered were (1) end fitting removal, (2) fission gas venting, (3) disassembly and close packing, and (4) shearing/immobilization. None of the findings ruled out any alternative on the basis of waste package considerations or long-term performance of the waste form. The third alternative offers flexibility in loading that may prove attractive in the various geologic media under consideration, greatly reduces the number of packages, and has the lowest unit cost. These studies were completed in October, 1981. Since then Westinghouse Electric Corporation and the Office of Nuclear Waste Isolation have completed studies in related fields. This report is now being published to provide publicly the background material that is contained within. 47 references, 28 figures, 31 tables.

  9. Buckling analysis of spent fuel basket

    SciTech Connect

    Lee, A.S.; Bumpas, S.E.

    1995-05-01

    The basket for a spent fuel shipping cask is subjected to compressive stresses that may cause global instability of the basket assemblies or local buckling of the individual members. Adopting the common buckling design practice in which the stability capacity of the entire structure is based on the performance of the individual members of the assemblies, the typical spent fuel basket, which is composed of plates and tubular structural members, can be idealized as an assemblage of columns, beam-columns and plates. This report presents the flexural buckling formulas for five load cases that are common in the basket buckling analysis: column under axial loads, column under axial and bending loads, plate under uniaxial loads, plate under biaxial loadings, and plate under biaxial loads and lateral pressure. The acceptance criteria from the ASME Boiler and Pressure Vessel Code are used to determine the adequacy of the basket components. Special acceptance criteria are proposed to address the unique material characteristics of austenitic stainless steel, a material which is frequently used in the basket assemblies.

  10. TRIGA spent-fuel storage criticality analysis

    SciTech Connect

    Ravnik, M.; Glumac, B.

    1996-06-01

    A criticality safety analysis of a pool-type storage for spent TRIGA Mark II reactor fuel is presented. Two independent computer codes are applied: the MCNP Monte Carlo code and the WIMS lattice cell code. Two types of fuel elements are considered: standard fuel elements with 12 wt% uranium concentration and FLIP fuel elements. A parametric study of spent-fuel storage lattice pitch, fuel element burnup, and water density is presented. Normal conditions and postulated accident conditions are analyzed. A strong dependence of the multiplication factor on the distance between the fuel elements and on the effective water density is observed. A multiplication factor <1 may be expected for an infinite array of fuel rods at center-to-center distances >6.5 cm, regardless of the fuel element type and burnup. At shorter distances, the subcriticality can be ensured only by adding absorbers to the array of fuel rods even if the fuel rods were burned to {approximately}20% burnup. The results of both codes agree well for normal conditions. The results show that WIMS may be used as a complement to the Monte Carlo code in some parts of the criticality analysis.

  11. Spent Nuclear Fuel Vibration Integrity Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao; Yan, Yong; Bevard, Bruce Balkcom

    2016-01-01

    The objective of this research is to collect dynamic experimental data on spent nuclear fuel (SNF) under simulated transportation environments using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT), the hot-cell testing technology developed at Oak Ridge National Laboratory (ORNL). The collected CIRFT data will be utilized to support ongoing spent fuel modeling activities, and support SNF transportation related licensing issues. Recent testing to understand the effects of hydride reorientation on SNF vibration integrity is also being evaluated. CIRFT results have provided insight into the fuel/clad system response to transportation related loads. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance, Fuel structure contributes to the SNF system stiffness, There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interaction, and SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous. Because of the non-homogeneous composite structure of the SNF system, finite element analyses (FEA) are needed to translate the global moment-curvature measurement into local stress-strain profiles. The detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained directly from a CIRFT system measurement. Therefore, detailed FEA is used to understand the global test response, and that data will also be presented.

  12. Transportation capabilities study of DOE-owned spent nuclear fuel

    SciTech Connect

    Clark, G.L.; Johnson, R.A.; Smith, R.W.; Abbott, D.G.; Tyacke, M.J.

    1994-10-01

    This study evaluates current capabilities for transporting spent nuclear fuel owned by the US Department of Energy. Currently licensed irradiated fuel shipping packages that have the potential for shipping the spent nuclear fuel are identified and then matched against the various spent nuclear fuel types. Also included are the results of a limited investigation into other certified packages and new packages currently under development. This study is intended to support top-level planning for the disposition of the Department of Energy`s spent nuclear fuel inventory.

  13. Assessment of Nuclear Resonance Fluorescence for Spent Nuclear Fuel Assay

    SciTech Connect

    Quiter, Brian; Ludewigt, Bernhard; Ambers, Scott

    2011-06-30

    In nuclear resonance fluorescence (NRF) measurements, resonances are excited by an external photon beam leading to the emission of gamma rays with specific energies that are characteristic of the emitting isotope. NRF promises the unique capability of directly quantifying a specific isotope without the need for unfolding the combined responses of several fissile isotopes as is required in other measurement techniques. We have analyzed the potential of NRF as a non-destructive analysis technique for quantitative measurements of Pu isotopes in spent nuclear fuel (SNF). Given the low concentrations of 239Pu in SNF and its small integrated NRF cross sections, the main challenge in achieving precise and accurate measurements lies in accruing sufficient counting statistics in a reasonable measurement time. Using analytical modeling, and simulations with the radiation transport code MCNPX that has been experimentally tested recently, the backscatter and transmission methods were quantitatively studied for differing photon sources and radiation detector types. Resonant photon count rates and measurement times were estimated for a range of photon source and detection parameters, which were used to determine photon source and gamma-ray detector requirements. The results indicate that systems based on a bremsstrahlung source and present detector technology are not practical for high-precision measurements of 239Pu in SNF. Measurements that achieve the desired uncertainties within hour-long measurements will either require stronger resonances, which may be expressed by other Pu isotopes, or require quasi-monoenergetic photon sources with intensities that are approximately two orders of magnitude higher than those currently being designed or proposed.This work is part of a larger effort sponsored by the Next Generation Safeguards Initiative to develop an integrated instrument, comprised of individual NDA techniques with complementary features, that is fully capable of

  14. Determination of spent nuclear fuel assembly multiplication with the differential die-away self-interrogation instrument

    NASA Astrophysics Data System (ADS)

    Kaplan, Alexis C.; Henzl, Vladimir; Menlove, Howard O.; Swinhoe, Martyn T.; Belian, Anthony P.; Flaska, Marek; Pozzi, Sara A.

    2014-09-01

    We present a novel method for determining the multiplication of a spent nuclear fuel assembly with a Differential Die-Away Self-Interrogation (DDSI) instrument. The signal, which is primarily created by thermal neutrons, is measured with four 3He detector banks surrounding a spent fuel assembly. The Rossi-alpha distribution (RAD) at early times reflects coincident events from single fissions as well as fission chains. Because of this fact, the early time domain contains information about both the fissile material and spontaneous fission material in the assembly being measured. A single exponential function fit to the early time domain of the RAD has a die-away time proportional to the spent fuel assembly (SFA) multiplication. This correlation was tested by simulating assay of 44 different SFAs with the DDSI instrument. The SFA multiplication was determined with a variance of 0.7%.

  15. Environmental safety aspects of the new spent nuclear fuel management and storage system at Ignalina NPP

    SciTech Connect

    Poskas, P.; Ragaisis, V.; Adomaitis, J. E.

    2007-07-01

    In the framework of the preparation for the decommissioning of the Ignalina Nuclear Power Plant (INPP) a new Interim Spent Nuclear Fuel Storage Facility (ISFSF) will be built in the existing sanitary protection zone (SPZ) of INPP. In addition to the ISFSF, the new spent nuclear fuel management activity will include all necessary spent nuclear fuel retrieval and packaging operations at the Reactor Units, transfer of storage casks to the ISFSF, and other activities appropriate to the chosen design solution and required for the safe removal of the existing spent nuclear fuel from storage pools and insertion into the new ISFSF. The Republic of Lithuania regulations require that the average annual dose to the critical group members of population due to operation of nuclear facility shall not exceed dose constraint. If several nuclear facilities are located in the same SPZ, the same dose constraint shall envelope radiological impacts from all operating and planned nuclear facilities. The paper discusses radiological safety assessment aspects as relevant for the new nuclear activity to be implemented in the SPZ of INPP considering specificity of Lithuanian regulatory requirements. The safety assessment methodology aspects, results and conclusions as concern public exposure are outlined and discussed. (authors)

  16. Bioleaching of valuable metals from spent lithium-ion mobile phone batteries using Aspergillus niger

    NASA Astrophysics Data System (ADS)

    Horeh, N. Bahaloo; Mousavi, S. M.; Shojaosadati, S. A.

    2016-07-01

    In this paper, a bio-hydrometallurgical route based on fungal activity of Aspergillus niger was evaluated for the detoxification and recovery of Cu, Li, Mn, Al, Co and Ni metals from spent lithium-ion phone mobile batteries under various conditions (one-step, two-step and spent medium bioleaching). The maximum recovery efficiency of 100% for Cu, 95% for Li, 70% for Mn, 65% for Al, 45% for Co, and 38% for Ni was obtained at a pulp density of 1% in spent medium bioleaching. The HPLC results indicated that citric acid in comparison with other detected organic acids (gluconic, oxalic and malic acid) had an important role in the effectiveness of bioleaching using A. niger. The results of FTIR, XRD and FE-SEM analysis of battery powder before and after bioleaching process confirmed that the fungal activities were quite effective. In addition, bioleaching achieved higher removal efficiency for heavy metals than the chemical leaching. This research demonstrated the great potential of bio-hydrometallurgical route to recover heavy metals from spent lithium-ion mobile phone batteries.

  17. Effect of ensiling time and exogenous protease addition to whole-plant corn silage of various hybrids, maturities, and chop lengths on nitrogen fractions and ruminal in vitro starch digestibility.

    PubMed

    Ferraretto, L F; Crump, P M; Shaver, R D

    2015-12-01

    The objective of this study was to evaluate the effects of ensiling time and exogenous protease addition on soluble CP (% of CP), ammonia-N (% of N), and ruminal in vitro starch digestibility (ivSD) of whole-plant corn silage (WPCS) from 3 hybrids, 2 maturities, and 2 chop lengths. Samples from 3 nonisogenic hybrids [brown midrib containing the bm3 gene mutation (BM3), dual-purpose (DP), or floury-leafy (LFY)] at 2 harvest maturities [2/3 kernel milk line (early) or 7d later (late)] with 2 theoretical lengths of cut settings (0.64 or 1.95cm) on a forage harvester were collected at harvest, treated with or without exogenous protease, and ensiled in triplicate in vacuum heat-sealed plastic bags for 0, 30, 60, 120, and 240d. Thus, the experiment consisted of 120 treatments (3 hybrids × 2 maturities × 2 chop lengths × 2 protease treatments × 5 time points) and 360 mini-silos (3 replications per treatment). Vitreousness, measured by dissection on unfermented kernels on the day of harvest, averaged 66.8, 65.0, and 59.0% for BM3, DP, and LFY, respectively. A protease × maturity interaction was observed with protease increasing ivSD in late but not early maturity. Ensiling time × hybrid interactions were observed for ammonia-N and soluble CP concentrations with greater values for FLY than other hybrids only after 120d of ensiling. Ensiling time × hybrid or protease × hybrid interactions were not observed for ivSD. Measurements of ivSD were greatest for FLY and lowest for BM3. Length of the ensiling period did not attenuate negative effects of kernel vitreousness or maturity on ivSD in WPCS. Results suggest that the dosage of exogenous protease addition used in the present study may reduce but not overcome the negative effects of maturity on ivSD in WPCS. No interactions between chop length and ensiling time or exogenous protease addition were observed for ivSD. PMID:26433421

  18. Near-field heat transfer at the spent fuel test-climax: a comparison of measurements and calculations

    SciTech Connect

    Patrick, W.C.; Montan, D.N.; Ballou, L.B.

    1981-08-21

    The Spent Fuel Test in the Climax granitic stock at the DOE Nevada Test Site is a test of the feasibility of storage and retrieval of spent nuclear reactor fuel in a deep geologic environment. Eleven spent fuel elements, together with six thermally identical electrical resistance heaters and 20 peripheral guard heaters, are emplaced 420 m below surface in a three-drift test array. This array was designed to simulate the near-field effects of thousands of canisters of nuclear waste and to evaluate the effects of heat alone, and heat plus ionizing radiation on the rock. Thermal calculations and measurements are conducted to determine thermal transport from the spent fuel and electrical resistance heaters. Calculations associated with the as-built Spent Fuel Test geometry and thermal source histories are presented and compared with thermocouple measurements made throughout the test array. Comparisons in space begin at the spent fuel canister and include the first few metres outside the test array. Comparisons in time begin at emplacement and progress through the first year of thermal loading in this multi-year test.

  19. Commercial Spent Nuclear Fuel Waste Package Misload Analysis

    SciTech Connect

    A. Alsaed

    2005-07-28

    The purpose of this calculation is to estimate the probability of misloading a commercial spent nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or burnup) outside the waste package design. The waste package designs are based on the expected commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1 and Table 1). For this calculation, a misloaded waste package is defined as a waste package that has a fuel assembly(s) loaded into it with an enrichment and/or burnup outside the waste package design. An example of this type of misload is a fuel assembly designated for the 21-PWR Control Rod waste package being incorrectly loaded into a 21-PWR Absorber Plate waste package. This constitutes a misloaded 21-PWR Absorber Plate waste package, because the reactivity (i.e., enrichment and/or burnup) of a 21-PWR Control Rod waste package fuel assembly is outside the design of a 21-PWR Absorber Plate waste package. These types of misloads (i.e., fuel assembly with enrichment and/or burnup outside waste package design) are the only types that are evaluated in this calculation. This calculation utilizes information from ''Frequency of SNF Misload for Uncanistered Fuel Waste Package'' (CRWMS M&O 1998) as the starting point. The scope of this calculation is limited to the information available. The information is based on the whole population of fuel assemblies and the whole population of waste packages, because there is no information about the arrival of the waste stream at this time. The scope of this calculation deviates from that specified in ''Technical Work Plan for: Risk and Criticality Department'' (BSC 2002a, Section 2.1.30) in that only waste package misload is evaluated. The remaining issues identified (i.e., flooding and geometry reconfiguration) will be addressed elsewhere. The intended use of the calculation is to provide information and inputs to the Preclosure Safety Analysis

  20. Commercial Spent Nuclear Fuel Waste Package Misload Analysis

    SciTech Connect

    J.K. Knudson

    2003-10-02

    The purpose of this calculation is to estimate the probability of misloading a commercial spent nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or burnup) outside the waste package design. The waste package designs are based on the expected commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1 and Table 1). For this calculation, a misloaded waste package is defined as a waste package that has a fuel assembly(s) loaded into it with an enrichment and/or burnup outside the waste package design. An example of this type of misload is a fuel assembly designated for the 21-PWR Control Rod waste package being incorrectly loaded into a 21-PWR Absorber Plate waste package. This constitutes a misloaded 21-PWR Absorber Plate waste package, because the reactivity (i.e., enrichment and/or burnup) of a 21-PWR Control Rod waste package fuel assembly is outside the design of a 21-PWR Absorber Plate waste package. These types of misloads (i.e., fuel assembly with enrichment and/or burnup outside waste package design) are the only types that are evaluated in this calculation. This calculation utilizes information from ''Frequency of SNF Misload for Uncanistered Fuel Waste Package'' (CRWMS M&O 1998) as the starting point. The scope of this calculation is limited to the information available. The information is based on the whole population of fuel assemblies and the whole population of waste packages, because there is no information about the arrival of the waste stream at this time. The scope of this calculation deviates from that specified in ''Technical Work Plan for: Risk and Criticality Department'' (BSC 2002a, Section 2.1.30) in that only waste package misload is evaluated. The remaining issues identified (i.e., flooding and geometry reconfiguration) will be addressed elsewhere. The intended use of the calculation is to provide information and inputs to the Preclosure Safety Analysis