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Sample records for 300mwe pwr npp

  1. Experience from the 300 MWe CFB Demontration Plant in China

    NASA Astrophysics Data System (ADS)

    Gauvillé, P.; Semedard, J.-C.; Darling, S.

    This paper will describe the background and current status of the 300MWe CFB Demonstration Project located at the Baima Power Plant in Sichuan Province. This project was the first 300MWe class CFB in China and the first project built under the Transfer of Technology from Alstom. The plant entered commercial operation in early 2006. The fuel is a high-ash anthracite which has presented significant challenges in terms of higher-than-expected ash content and top size. While this fuel has been problematic for the adjacent suspension-fired boilers, performance in the CFB boiler has been excellent, with low carbon content in the ash, low turndown and low emissions. Key boiler performance parameters will be described along with a comparison of design and actual performance and the operational experience will be addressed. Finally, the paper will describe Alstom's process for scaling the CFB technology from 300MWe to 600MWe, and our supercritical CFB design.

  2. Operation Experience and Performance of the First 300MWe CFB Boiler Developed by DBC in China

    NASA Astrophysics Data System (ADS)

    Guo, Q.; Zheng, X. S.; Zhou, Q.; Nie, L.; Liu, T. S.; Hu, X. K.; Lu, J. F.

    In this paper, general layout, design, operational experience and performance of the first 300MWe circulating fluidized bed (CFB) boiler that developed by Dongfang Boiler Group Co., Ltd China, are introduced. The furnace was with large width-depth ratio. The problems occurred during in commissioning were analyzed and the corresponding modifications were presented. Cold-state experiment and operation experience showed that both fluidization quality and circulating flow rate meet the designated value in the frunace. The imbalance of circulating material flow caused by asymmetric layout of three cyclones was very limited. Heating surfaces were safe except wing wall superheater located in upper part of the furnace was overheated at low load. After commissioning, the boiler was correspondingly modified and its performance was excellent.

  3. Improved NOx emissions and combustion characteristics for a retrofitted down-fired 300-MWe utility boiler.

    PubMed

    Li, Zhengqi; Ren, Feng; Chen, Zhichao; Liu, Guangkui; Xu, Zhenxing

    2010-05-15

    A new technique combining high boiler efficiency and low-NO(x) emissions was employed in a 300MWe down-fired boiler as an economical means to reduce NO(x) emissions in down-fired boilers burning low-volatile coals. Experiments were conducted on this boiler after the retrofit with measurements taken of gas temperature distributions along the primary air and coal mixture flows and in the furnace, furnace temperatures along the main axis and gas concentrations such as O(2), CO and NO(x) in the near-wall region. Data were compared with those obtained before the retrofit and verified that by applying the combined technique, gas temperature distributions in the furnace become more reasonable. Peak temperatures were lowered from the upper furnace to the lower furnace and flame stability was improved. Despite burning low-volatile coals, NO(x) emissions can be lowered by as much as 50% without increasing the levels of unburnt carbon in fly ash and reducing boiler thermal efficiency. PMID:20429548

  4. The heat transfer coefficients of the heating surface of 300 MWe CFB boiler

    NASA Astrophysics Data System (ADS)

    Wu, Haibo; Zhang, Man; Lu, Qinggang; Sun, Yunkai

    2012-08-01

    A study of the heat transfer about the heating surface of three commercial 300 MWe CFB boilers was conducted in this work. The heat transfer coefficients of the platen heating surface, the external heat exchanger (EHE) and cyclone separator were calculated according to the relative operation data at different boiler loads. Moreover, the heat transfer coefficient of the waterwall was calculated by heat balance of the hot circuit of the CFB boiler. With the boiler capacity increasing, the heat transfer coefficients of these heating surface increases, and the heat transfer coefficient of the water wall is higher than that of the platen heating surface. The heat transfer coefficient of the EHE is the highest in high boiler load, the heat transfer coefficient of the cyclone separator is the lowest. Because the fired coal is different from the design coal in No.1 boiler, the ash content of the fired coal is much lower than that of the design coal. The heat transfer coefficients which calculated with the operation data are lower than the previous design value and that is the reason why the bed temperature is rather high during the boiler operation in No.1 boiler.

  5. Application of multifuel reburn for NOx control on a 300 MWe boiler in Ukraine. Report for October 1994--December 1995

    SciTech Connect

    Hall, R.E.; Miller, C.A.; Payne, R.; Yakushin, E.; Mospan, J.

    1996-01-01

    The paper gives results of a program to design two reburn systems for operation on 300 MWe, coal-fired utility boilers operating in Ukraine. One is a natural-gas-fired system designed by ABB Combustion Engineering, installed in September 1992, and continuing to operate with a 50 percent nitrogen oxides (NOx) reduction. The paper summarizes the natural gas reburn test results. Emphasis is placed on the second demonstration, a multifuel (natural gas, oil, and/or coal) reburn system for which a conceptual design has been completed by Energy and Environmental Research Corp. Engineering drawings are being prepared by the Karkov Design Bureau in Ukraine.

  6. NPP Launch

    NASA Video Gallery

    NASA's National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) spacecraft was launched aboard a Delta II rocket at 5:48 a.m. EDT today, on a mission to measure ...

  7. NPP Prelaunch Webcast

    NASA Video Gallery

    The NPP Pre-Launch Webcast looks at NASA’s upcoming NPOESS Preparatory Project (NPP) mission. NPP represents a critical first step in building the next-generation of Earth-observing satellites. T...

  8. Analysis of PWR RCS Injection Strategy During Severe Accident

    SciTech Connect

    Wang, S.-J.; Chiang, K.-S.; Chiang, S.-C.

    2004-05-15

    Reactor coolant system (RCS) injection is an important strategy for severe accident management of a pressurized water reactor (PWR) system. Maanshan is a typical Westinghouse PWR nuclear power plant (NPP) with large, dry containment. The severe accident management guideline (SAMG) of Maanshan NPP is developed based on the Westinghouse Owners Group (WOG) SAMG.The purpose of this work is to analyze the RCS injection strategy of PWR system in an overheated core condition. Power is assumed recovered as the vessel water level drops to the bottom of active fuel. The Modular Accident Analysis Program version 4.0.4 (MAAP4) code is chosen as a tool for analysis. A postulated station blackout sequence for Maanshan NPP is cited as a reference case for this analysis. The hot leg creep rupture occurs during the mitigation action with immediate injection after power recovery according to WOG SAMG, which is not desired. This phenomenon is not considered while developing the WOG SAMG. Two other RCS injection methods are analyzed by using MAAP4. The RCS injection strategy is modified in the Maanshan SAMG. These results can be applied for typical PWR NPPs.

  9. NPP: The Five Instruments

    NASA Video Gallery

    The NPP satellite has 5 instruments on board: VIIRS, CERES, CrIS, ATMS, and OMPS. Each one will deliver a specific set of data helping weather prediction and climate studies. This video is a quick ...

  10. NPP Beauty Pass Animation

    NASA Video Gallery

    An animator's conception shows the NPOESS Preparatory Project (NPP) satellite orbiting the earth and interpreting weather data through it's myriad sensors. The Satellite is part of a bridge mission...

  11. NPP and the Earth System

    NASA Video Gallery

    NPP is a continuation of the existing Earth-observing satellites and it builds on the legacy of multi decades of critical data. NPP will continue to deliver data to all users on Earth who will use ...

  12. Suomi Npp Products Performance

    NASA Astrophysics Data System (ADS)

    Zhou, L.

    2014-12-01

    A suite of Sensor Data Records (SDRs) and Environment Data Records (EDRs) is generated from the Joint Polar Satellite System (JPSS) operational environmental satellite system. The products include atmospheric, ocean, land surface and cryospheric products from the Visible Infrared Imaging Radiometer Suite (VIIRS); atmospheric sounding products from the Cross-track Infrared Sounder (CrIS) and the Advance Technology Microwave Sounder (ATMS); and ozone products from the Ozone Mapping and Profiler Suite (OMPS). These EDRs undergo a rigorous validation process and algorithm updates to achieve a product maturity needed for end user applications. Since the successful launch of Suomi National Polar Partnership (SNPP) satellite in October 2011, significant progresses have been made on calibration and validation of the SNPP data products. By far all products were publicly available and most products were ready for operational evaluation. Most products also are expected to meet requirements and work is underway to reach validated maturity status and fully operational use. Further developments and improvements of the algorithms for J1 have been planned based on the JPSS requirements and lessons learned from SNPP. Sensitivity and impact studies are performed as sensor test data become available. For the majority of data products, no significant changes in sensor input and corresponding sensor degradation are expected. However, the J1 products will undergo the same rigorous calibration and validation process as the S-NPP products once the on-orbit data are available. The schedule for the maturity of the J1 data products however is expected to be accelerated compared to that for S-NPP as lessons learned from the S-NPP mission will be applied to the J1 satellite data. In the presentation, we will provide an overview of the latest SNPP data products' quality status and the plan forward for JPSS-1 algorithm updates.

  13. Technology for NPP decantate treatment realized at Kola NPP

    SciTech Connect

    Stakhiv, Michael; Avezniyazov, Slava; Savkin, Alexander; Fedorov, Denis; Dmitriev, Sergei; Kornev, Vladimir

    2007-07-01

    At Moscow SIA 'Radon' jointly with JSC 'Alliance Gamma', the technology for NPP Decantate Treatment was developed, tested and realized at Kola NPP. This technology consists of dissolving the salt residue and subsequent treatment by ozonization, separation of the deposits formed from ozonization and selective cleaning by ferro-cyanide sorbents. The nonactive salt solution goes to an industrial waste disposal site or a repository specially developed at NPP sites for 'exempt waste' products by IAEA classification. This technology was realized at Kola NPP in December 2006 year. At this time more than 1000 m{sup 3} of decantates log time stored are treated. It allows solving very old problem to empty decantates' tanks at NPPs in environmentally safe manner and with high volume reduction factor. (authors)

  14. NPOESS Preparatory Project (NPP) Science Overview

    NASA Technical Reports Server (NTRS)

    Butler, James J.

    2011-01-01

    NPP Instruments are: (1) well understood thanks to instrument comprehensive test, characterization and calibration programs. (2) Government team ready for October 25 launch followed by instrument activation and Intensive Calibration/Validation (ICV). NPP Data Products preliminary work includes: (1) JPSS Center for Satellite Applications and Research (STAR) team ready to support NPP ICV and operational data products. (2) NASA NPP science team ready to support NPP ICV and EOS data continuity.

  15. PWR AXIAL BURNUP PROFILE ANALYSIS

    SciTech Connect

    J.M. Acaglione

    2003-09-17

    The purpose of this activity is to develop a representative ''limiting'' axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the ''end-effect''. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package. The scope of this calculation covers an initial enrichment range of 3.0 through 5.0 wt% U-235 and a burnup range of 10 through 50 GWd/MTU. This activity supports the validation of the process for ensuring conservative generation of spent fuel isotopics with respect to criticality safety applications, and the use of burnup credit for commercial spent nuclear fuel. The intended use of these results will be in the development of PWR waste package loading curves, and applications involving burnup credit. Limitations of this evaluation are that the limiting profiles are only confirmed for use with the B&W 15 x 15 fuel assembly design. However, this assembly design is considered bounding of all other typical commercial PWR fuel assembly designs. This calculation is subject to the Quality Assurance Requirements and Description (QARD) because this activity supports investigations of items or barriers on the Q-list (YMP 2001).

  16. NPP: Why Another Earth-Observing Satellite?

    NASA Video Gallery

    NPP will soon be NASA's newest Earth-observing satellite. To showcase how NPP will be used for both understanding the health of our planet now -- as well as how things might change in the future --...

  17. PWR fuel behavior: lessons learned from LOFT. [PWR

    SciTech Connect

    Russell, M.L.

    1981-01-01

    A summary of the experience with the Loss-of-Fluid Test (LOFT) fuel during loss-of-coolant experiments (LOCEs), operational and overpower transient tests and steady-state operation is presented. LOFT provides unique capabilities for obtaining pressurized water reactor (PWR) fuel behavior information because it features the representative thermal-hydraulic conditions which control fuel behavior during transient conditions and an elaborate measurement system to record the history of the fuel behavior.

  18. Analysis of a rod withdrawal in a PWR core with the neutronic- thermalhydraulic coupled code RELAP/PARCS and RELAP/VALKIN

    SciTech Connect

    Miro, R.; Maggini, F.; Barrachina, T.; Verdu, G.; Gomez, A.; Ortego, A.; Murillo, J. C.

    2006-07-01

    The Reactor Ejection Accident (REA) belongs to the Reactor Initiated Accidents (RIA) category of accidents and it is part of the licensing basis accident analyses required for pressure water reactors (PWR). The REA at hot zero power (HZP) is characterized by a single rod ejection from a core position with a very low power level. The evolution consists basically of a continuous reactivity insertion. The main feature limiting the consequences of the accident in a PWR is the Doppler Effect. To check the performance of the coupled code RELAP5/PARCS2.5 and RELAP5/VALKIN a REA in Trillo NPP is simulated. These analyses will allow knowing more accurately the PWR real plant phenomenology in the RIA most limiting conditions. (authors)

  19. FEASIBILITY AND EXPEDIENCE TO VITRIFY NPP OPERATIONAL WASTE

    SciTech Connect

    LIFANOV, F.A.; OJOVAN, M.I.; STEFANOVSKY, S.V.; BURCL, R.

    2003-02-27

    Operational radioactive waste is generated during routine operation of NPP. Process waste is mainly generated by treatment of water from reactor or ancillaries including spent fuel storage pools and some decontamination operations. Typical process wastes of pressurized water reactors (PWR or WWER) are borated water concentrates, whereas typical process wastes of boiling and RBMK type reactors are water concentrates with no boron content. NPP operational wastes are classified as low and intermediate level waste (LILW). NPP operational waste must be solidified in order to ensure safe conditions of storage and disposal. Currently the most promising solidification method for this waste is the vitrification technology. Vitrification of NPP operational waste is a relative new option being developed for last years. Nevertheless there is already accumulated operational experience on vitrifying low and intermediate level waste in Russian Federation at Moscow SIA ''Radon'' vitrification plant. This plant uses the most advanced type induction high frequency melters that facilitate the melting process and significantly reduce the generation of secondary waste and henceforth the overall cost. The plant was put into operation by the end of 1999. It has three operating cold crucible melters with the overall capacity up to 75 kg/h. The vitrification technology comprises a few stages, starting with evaporation of excess water from liquid radioactive waste, followed by batch preparation, glass melting, and ending with vitrified waste blocks and some relative small amounts of secondary waste. First of all since the original waste contain as main component water, this water is removed from waste through evaporation. Then the remaining salt concentrate is mixed with necessary technological additives, thus a glass-forming batch is formed. The batch is fed into melters where the glass melting occurs. From here there are two streams: one is the glass melt containing the most part of

  20. Does climate directly influence NPP globally?

    PubMed

    Chu, Chengjin; Bartlett, Megan; Wang, Youshi; He, Fangliang; Weiner, Jacob; Chave, Jérôme; Sack, Lawren

    2016-01-01

    The need for rigorous analyses of climate impacts has never been more crucial. Current textbooks state that climate directly influences ecosystem annual net primary productivity (NPP), emphasizing the urgent need to monitor the impacts of climate change. A recent paper challenged this consensus, arguing, based on an analysis of NPP for 1247 woody plant communities across global climate gradients, that temperature and precipitation have negligible direct effects on NPP and only perhaps have indirect effects by constraining total stand biomass (Mtot ) and stand age (a). The authors of that study concluded that the length of the growing season (lgs ) might have a minor influence on NPP, an effect they considered not to be directly related to climate. In this article, we describe flaws that affected that study's conclusions and present novel analyses to disentangle the effects of stand variables and climate in determining NPP. We re-analyzed the same database to partition the direct and indirect effects of climate on NPP, using three approaches: maximum-likelihood model selection, independent-effects analysis, and structural equation modeling. These new analyses showed that about half of the global variation in NPP could be explained by Mtot combined with climate variables and supported strong and direct influences of climate independently of Mtot , both for NPP and for net biomass change averaged across the known lifetime of the stands (ABC = average biomass change). We show that lgs is an important climate variable, intrinsically correlated with, and contributing to mean annual temperature and precipitation (Tann and Pann ), all important climatic drivers of NPP. Our analyses provide guidance for statistical and mechanistic analyses of climate drivers of ecosystem processes for predictive modeling and provide novel evidence supporting the strong, direct role of climate in determining vegetation productivity at the global scale. PMID:26442433

  1. Suomi NPP VIIRS Imagery evaluation

    NASA Astrophysics Data System (ADS)

    Hillger, Donald; Seaman, Curtis; Liang, Calvin; Miller, Steven; Lindsey, Daniel; Kopp, Thomas

    2014-06-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) combines the best aspects of both civilian and military heritage instrumentation. VIIRS has improved capabilities over its predecessors: a wider swath width and much higher spatial resolution at swath edge. The VIIRS day-night band (DNB) is sensitive to very low levels of visible light and is capable of detecting low clouds, land surface features, and sea ice at night, in addition to light emissions from both man-made and natural sources. Imagery from the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite has been in the checkout process since its launch on 28 October 2011. The ongoing evaluation of VIIRS Imagery helped resolve several imagery-related issues, including missing radiance measurements. In particular, near-constant contrast imagery, derived from the DNB, had a large number of issues to overcome, including numerous missing or blank-fill images and a stray light leakage problem that was only recently resolved via software fixes. In spite of various sensor issues, the VIIRS DNB has added tremendous operational and research value to Suomi NPP. Remarkably, it has been discovered to be sensitive enough to identify clouds even in very low light new moon conditions, using reflected light from the Earth's airglow layer. Impressive examples of the multispectral imaging capabilities are shown to demonstrate its applications for a wide range of operational users. Future members of the Joint Polar Satellite System constellation will also carry and extend the use of VIIRS. Imagery evaluation will continue with these satellites to ensure the quality of imagery for end users.

  2. Suomi NPP Ground System Performance

    NASA Astrophysics Data System (ADS)

    Grant, K. D.; Bergeron, C.

    2013-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The first satellite in the JPSS constellation, known as the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, was launched on 28 October 2011, and is currently undergoing product calibration and validation activities. As products reach a beta level of maturity, they are made available to the community through NOAA's Comprehensive Large Array-data Stewardship System (CLASS). CGS's data processing capability processes the satellite data from the Joint Polar Satellite System satellites to provide environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to NOAA and Department of Defense (DoD) processing centers operated by the United States government. CGS is currently processing and delivering SDRs and EDRs for Suomi NPP and will continue through the lifetime of the Joint Polar Satellite System programs. Following the launch and sensor activation phase of the Suomi NPP mission, full volume data traffic is now flowing from the satellite through CGS's C3, data processing, and data delivery systems. Ground system performance is critical for this operational system. As part of early system checkout, Raytheon measured all aspects of data acquisition, routing, processing, and delivery to ensure operational performance requirements are met, and will continue to be met throughout the mission. Raytheon developed a tool to measure, categorize, and

  3. NPP VIIRS geometric performance status

    NASA Astrophysics Data System (ADS)

    Lin, Guoqing; Wolfe, Robert E.; Nishihama, Masahiro

    2011-10-01

    Visible Infrared Imager Radiometer Suite (VIIRS) instrument on-board the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) satellite is scheduled for launch in October, 2011. It is to provide satellite measured radiance/reflectance data for both weather and climate applications. Along with radiometric calibration, geometric characterization and calibration of Sensor Data Records (SDRs) are crucial to the VIIRS Environmental Data Record (EDR) algorithms and products which are used in numerical weather prediction (NWP). The instrument geometric performance includes: 1) sensor (detector) spatial response, parameterized by the dynamic field of view (DFOV) in the scan direction and instantaneous FOV (IFOV) in the track direction, modulation transfer function (MTF) for the 17 moderate resolution bands (M-bands), and horizontal spatial resolution (HSR) for the five imagery bands (I-bands); 2) matrices of band-to-band co-registration (BBR) from the corresponding detectors in all band pairs; and 3) pointing knowledge and stability characteristics that includes scan plane tilt, scan rate and scan start position variations, and thermally induced variations in pointing with respect to orbital position. They have been calibrated and characterized through ground testing under ambient and thermal vacuum conditions, numerical modeling and analysis. This paper summarizes the results, which are in general compliance with specifications, along with anomaly investigations, and describes paths forward for characterizing on-orbit BBR and spatial response, and for improving instrument on-orbit performance in pointing and geolocation.

  4. NPP VIIRS Geometric Performance Status

    NASA Technical Reports Server (NTRS)

    Lin, Guoqing; Wolfe, Robert E.; Nishihama, Masahiro

    2011-01-01

    Visible Infrared Imager Radiometer Suite (VIIRS) instrument on-board the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) satellite is scheduled for launch in October, 2011. It is to provide satellite measured radiance/reflectance data for both weather and climate applications. Along with radiometric calibration, geometric characterization and calibration of Sensor Data Records (SDRs) are crucial to the VIIRS Environmental Data Record (EDR) algorithms and products which are used in numerical weather prediction (NWP). The instrument geometric performance includes: 1) sensor (detector) spatial response, parameterized by the dynamic field of view (DFOV) in the scan direction and instantaneous FOV (IFOV) in the track direction, modulation transfer function (MTF) for the 17 moderate resolution bands (M-bands), and horizontal spatial resolution (HSR) for the five imagery bands (I-bands); 2) matrices of band-to-band co-registration (BBR) from the corresponding detectors in all band pairs; and 3) pointing knowledge and stability characteristics that includes scan plane tilt, scan rate and scan start position variations, and thermally induced variations in pointing with respect to orbital position. They have been calibrated and characterized through ground testing under ambient and thermal vacuum conditions, numerical modeling and analysis. This paper summarizes the results, which are in general compliance with specifications, along with anomaly investigations, and describes paths forward for characterizing on-orbit BBR and spatial response, and for improving instrument on-orbit performance in pointing and geolocation.

  5. Changing NPP consumption patterns in the Holocene: from Megafauna "liberated" NPP to "ecological bankruptcy"

    NASA Astrophysics Data System (ADS)

    Doughty, C.

    2015-12-01

    There have been vast changes in how net primary production (NPP) is consumed by humans and animals during the Holocene beginning with a potential increase in availability following the Pleistocene megafauna extinctions. This was followed by the development of agriculture which began to gradually restrict availability of NPP for wild animals. Finally, humans entered the industrial era using non-plant based energies to power societies. Here I ask the following questions about these three energy transitions: 1. How much NPP energy may have become available following the megafauna extinctions? 2. When did humans, through agriculture and domestic animals, consume more NPP than wild mammals in each country? 3. When did humans and wild mammals use more energy than was available in total NPP in each country? To answer this last question I calculate NPP consumed by wild animals, crops, livestock, and energy use (all converted to units of MJ) and compare this with the total potential NPP (also in MJ) for each country. We develop the term "ecological bankruptcy" to refer to the level of consumption where not all energy needs can be met by the country's NPP. Currently, 82 countries and a net population of 5.4 billion are in the state of ecologically bankruptcy, crossing this threshold at various times over the past 40 years. By contrast, only 52 countries with a net population of 1.2 billion remain ecologically solvent. Overall, the Holocene has seen remarkable changes in consumption patterns of NPP, passing through three distinct phases. Humans began in a world where there was 1.6-4.1% unclaimed NPP to consume. From 1700-1850, humans began to consume more than wild animals (globally averaged). At present, >82% of people live in countries where not even all available plant matter could satisfy our energy demands.

  6. Simulator experiments: effects of NPP operator experience on performance

    SciTech Connect

    Beare, A.N.; Gray, L.H.

    1984-01-01

    During the FY83 research, a simulator experiment was conducted at the control room simulator for a GE Boiling Water Reactor (BWR) NPP. The research subjects were licensed operators undergoing requalification training and shift technical advisors (STAs). This experiment was designed to investigate the effects of senior reactor operator (SRO) experience, operating crew augmentation with an STA and practice, as a crew, upon crew and individual operator performance, in response to anticipated plant transients. Sixteen two-man crews of licensed operators were employed in a 2 x 2 factorial design. The SROs leading the crews were split into high and low experience groups on the basis of their years of experience as an SRO. One half of the high- and low-SRO experience groups were assisted by an STA. The crews responded to four simulated plant casualties. A five-variable set of content-referenced performance measures was derived from task analyses of the procedurally correct responses to the four casualties. System parameters and control manipulations were recorded by the computer controlling the simulator. Data on communications and procedure use were obtained from analysis of videotapes of the exercises. Questionnaires were used to collect subject biographical information and data on subjective workload during each simulated casualty. For four of the five performance measures, no significant differences were found between groups led by high (25 to 114 months) and low (1 to 17 months as an SRO) experience SROs. However, crews led by low experience SROs tended to have significantly shorter task performance times than crews led by high experience SROs. The presence of the STA had no significant effect on overall team performance in responding to the four simulated casualties. The FY84 experiments are a partial replication and extension of the FY83 experiment, but with PWR operators and simulator.

  7. NPP After Launch: Characterizing ATMS Performance

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn

    2011-01-01

    The NPOESS Preparatory Project (NPP) mission is scheduled to launch in the fall of 2011. Although several teams from the government and the instrument contractor will be assessing and characterizing the performance of the Advanced Technology Microwave Sounder (ATMS) and the Cross-track Infrared Sounder (CrIS) sounding suite, the NASA NPP Science Team will be paying particular attention to the aspects of these sensors that affect their utility for atmospheric and climate research. In this talk we discuss relevant aspects of ATMS and our post launch analysis approach.

  8. Horizontal Drop of 21- PWR Waste Package

    SciTech Connect

    A.K. Scheider

    2007-01-31

    The objective of this calculation is to determine the structural response of the waste package (WP) dropped horizontally from a specified height. The WP used for that purpose is the 21-Pressurized Water Reactor (PWR) WP. The scope of this document is limited to reporting the calculation results in-terms of stress intensities. This calculation is associated with the WP design and was performed by the Waste Package Design group in accordance with the ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 16). AP-3.12Q, ''Calculations'' (Ref. 1 1) is used to perform the calculation and develop the document. The sketches attached to this calculation provide the potential dimensions and materials for the 21-PWR WP design.

  9. PWR secondary water chemistry guidelines: Revision 3. Final report

    SciTech Connect

    Lurie, S.; Bucci, G.; Johnson, L.; King, M.; Lamanna, L.; Morgan, E.; Bates, J.; Burns, R.; Eaker, R.; Ward, G.; Linnenbom, V.; Millet, P.; Paine, J.P.; Wood, C.J.; Gatten, T.; Meatheany, D.; Seager, J.; Thompson, R.; Brobst, G.; Connor, W.; Lewis, G.; Shirmer, R.; Gillen, J.; Kerns, M.; Jones, V.; Lappegaard, S.; Sawochka, S.; Smith, F.; Spires, D.; Pagan, S.; Gardner, J.; Polidoroff, T.; Lambert, S.; Dahl, B.; Hundley, F.; Miller, B.; Andersson, P.; Briden, D.; Fellers, B.; Harvey, S.; Polchow, J.; Rootham, M.; Fredrichs, T.; Flint, W.

    1993-05-01

    An effective, state-of-the art secondary water chemistry control program is essential to maximize the availability and operating life of major PWR components. Furthermore, the costs related to maintaining secondary water chemistry will likely be less than the repair or replacement of steam generators or large turbine rotors, with resulting outages taken into account. The revised PWR secondary water chemistry guidelines in this report represent the latest field and laboratory data on steam generator corrosion phenomena. This document supersedes Interim PWR Secondary Water Chemistry Recommendations for IGA/SCC Control (EPRI report TR-101230) as well as PWR Secondary Water Chemistry Guidelines--Revision 2 (NP-6239).

  10. NPOESS Preparatory Project (NPP) Environmental Products

    NASA Astrophysics Data System (ADS)

    Grant, K. D.; Hughes, R.; Andreas, N. S.

    2010-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes NPOESS satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to NOAA and DoD processing centers operated by the United States government. The IDPS will process EDRs beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. Northrop Grumman Aerospace Systems Algorithms and Data Products (A&DP) organization is responsible for the algorithms that produce the EDRs, including their quality aspects. Given a launch date for the NPP spacecraft on the near horizon and the need for users to become familiar with NPP environmental products, this paper will provide an overview of all the products generated by the IDPS and provided to NOAA’s Comprehensive Large Array-data Stewardship System (CLASS) for public distribution. It will discuss each of the 25 NPP EDRs in detail, including a description of the EDR, its size, coverage, measurement range, and expected uses.

  11. Challenges for Lithuania: Ignalina NPP Early Closure

    SciTech Connect

    Teskeviciene, Birute

    2008-01-15

    As a condition of accession into the European Union (EU), Lithuania is committed to the closure and decommissioning of Ignalina NPP comprising two RBMK-1500 reactor units (Fig. 1). It was agreed in a special protocol to the Accession Treaty that, in return for adequate EU financial assistance, Unit 1 would be closed before 2005 and Unit 2 by the end of 2009. The first unit was duly shut down on December 31, 2004. Lithuania, which has borders with Russia (Kaliningrad territory), Poland, Latvia and Belarus, spent fifty years as part of the Soviet Union and was deeply integrated into its economy and electrical infrastructure. At the break-up of the USSR, Lithuania inherited electricity generating capacity designed to supply the north-west region including ownership of Ignalina NPP located in the north-east of the country. Ignalina NPP Unit 1 was commissioned in 1983, Unit 2 in 1987; the planned lifespan of each unit was 30 years. Construction of a third unit was started but never completed. Since Lithuania became independent in 1990, Ignalina NPP has typically contributed more than 70% of national power supply. The town of Visaginas (population approx. 30,000) was purpose built to serve the plant and staff were brought in from throughout the USSR. With 3200 direct employees, Ignalina NPP remains by far the largest employer. Although there are pockets of Russian-language speakers in communities throughout Lithuania, Visaginas is the only example on a whole-town scale. Thus closure of Ignalina NPP within the restricted timescale required by the EU Accession Treaty commitment set an exceptional challenge to Lithuania. However, since the preparatory phase of decommissioning started in 2000, notable progress has been made, experience gained and lessons learnt. At present Unit 1 remains partially fueled in a state of care and maintenance. Partly burnt fuel is being transferred from Unit 1 to Unit 2 for further irradiation in order to minimize the commitment of new fuel

  12. Zebra: An advanced PWR lattice code

    SciTech Connect

    Cao, L.; Wu, H.; Zheng, Y.

    2012-07-01

    This paper presents an overview of an advanced PWR lattice code ZEBRA developed at NECP laboratory in Xi'an Jiaotong Univ.. The multi-group cross-section library is generated from the ENDF/B-VII library by NJOY and the 361-group SHEM structure is employed. The resonance calculation module is developed based on sub-group method. The transport solver is Auto-MOC code, which is a self-developed code based on the Method of Characteristic and the customization of AutoCAD software. The whole code is well organized in a modular software structure. Some numerical results during the validation of the code demonstrate that this code has a good precision and a high efficiency. (authors)

  13. Development of the preliminary procedure for a national nuclear safety authority staff acting during the PWR NPP accident

    SciTech Connect

    Kostadinov, V.

    1997-12-01

    We present the development of the new preliminary procedure for a National Nuclear Safety Authority staff preparedness for action in the case of a Pressurized Water Reactor Nuclear Power Plant accident. The procedures are generic and equally applicable for advanced nuclear plants. The basic goal of the procedure is systematic determination of the responsibilities of the staff expert group(s) members for accident analysis and consequences prediction. Moreover, the procedure describes anticipated practices of an expert group acting during a plant accident. Different sources will define the state(s) of the plant as: the plant form for initial notification of an accident, the particular form for specific plant information, etc. By this procedure we propose three expert groups successively to work up to eight hours each, in the circumstances of an accident. We suppose the expert group to have mostly five members each. The members should have different tasks for resolution, defined by the procedure. The head of the group will coordinate group members work during an accident. Group members have to be qualified and acquainted with all adequate references. In the paper we present a newly devised agenda with presumed duties of each member of the group. Furthermore, we also composed a special form for information exchange between the utility and regulatory staff member during an accident. 8 refs., 1 fig.

  14. Post-PKS Tailoring Steps of a Disaccharide-Containing Polyene NPP in Pseudonocardia autotrophica

    PubMed Central

    Kim, Hye-Jin; Kim, Min-Kyung; Lee, Mi-Jin; Won, Hyung-Jin; Choi, Si-Sun; Kim, Eung-Soo

    2015-01-01

    A novel polyene compound NPP identified in a rare actinomycetes, Pseudonocardia autotrophica KCTC9441, was shown to contain an aglycone identical to nystatin but to harbor a unique di-sugar moiety, mycosaminyl-(α1-4)-N-acetyl-glucosamine, which led to higher solubility and reduced hemolytic activity. Although the nppDI was proved to be responsible for the transfer of first polyene sugar, mycosamine in NPP biosynthesis, the gene responsible for the second sugar extending glycosyltransferase (GT) as well as NPP post-PKS tailoring mechanism remained unknown. Here, we identified a NPP-specific second sugar extending GT gene named nppY, located at the edge of the NPP biosynthetic gene cluster. Targeted nppY gene deletion and its complementation proved that nppY is indeed responsible for the transfer of second sugar, N-acetyl-glucosamine in NPP biosynthesis. Site-directed mutagenesis on nppY also revealed several amino acid residues critical for NppY GT function. Moreover, a combination of deletions and complementations of two GT genes (nppDI and nppY) and one P450 hydroxylase gene (nppL) involved in the NPP post-PKS biosynthesis revealed that NPP aglycone is sequentially modified by the two different GTs encoded by nppDI and nppY, respectively, followed by the nppL-driven regio-specific hydroxylation at the NPP C10 position. These results set the stage for the biotechnological application of sugar diversification for the biosynthesis of novel polyene compounds in actinomycetes. PMID:25849545

  15. [Plutonium at the ecosystems of impact zone the Beloyarsk NPP].

    PubMed

    Mikhaĭlovskaia, L N; Molchanova, I V; Karavaeva, E N

    2007-01-01

    The distribution of the plutonium at the ecosystems of impact zone the Beloyarsk NPP was studied. Higher quantity of Pu (to 500 Bq/m2) was revealed in the bottom sediments of the Olkhovsk bog where low-level radioactive water of the Beloyarsk NPP have been discharged. The total amount of the radionuclide in a soil cover did not exceed 140 Bq/m2. The contribution of the Beloyarsk NPP to contamination of the investigated ecosystems was accounted with using ratio 238Pu/239.240Pu. It was 64.1-99.3% both in the bottom sediments and soils. PMID:17953434

  16. N-16 monitors: Almaraz NPP experience

    SciTech Connect

    Adrada, J.

    1997-02-01

    Almaraz Nuclear Power Plant has installed N-16 monitors - one per steam generator - to control the leakage rate through the steam generator tubes after the application of leak before break (LBB) criteria for the top tube sheet (TTS). After several years of operation with the N-16 monitors, Almaraz NPP experience may be summarized as follows: N-16 monitors are very useful to follow the steam generator leak rate trend and to detect an incipient tube rupture; but they do not provide an exact absolute leak rate value, mainly when there are small leaks. The evolution of the measured N-16 leak rates varies along the fuel cycle, with the same trend for the 3 steam generators. This behaviour is associated with the primary water chemistry evolution along the cycle.

  17. Environmental Impact Assessment (EIA) Process of V1 NPP Decommissioning

    SciTech Connect

    Matejovic, Igor; Polak, Vincent

    2007-07-01

    Through the adoption of Governmental Resolution No. 801/99 the Slovak Republic undertook a commitment to shutdown units 1 and 2 of Jaslovske Bohunice V 1 NPP (WWER 230 reactor type) in 2006 and 2008 respectively. Therefore the more intensive preparation of a decommissioning documentation has been commenced. Namely, the VI NPP Conceptual Decommissioning Plan and subsequently the Environmental Impact Assessment Report of VI NPP Decommissioning were developed. Thus, the standard environmental impact assessment process was performed and the most suitable alternative of V1 NPP decommissioning was selected as a basis for development of further decommissioning documents. The status and main results of the environmental impact assessment process and EIA report are discussed in more detail in this paper. (authors)

  18. High Cycle Thermal Fatigue in French PWR

    SciTech Connect

    Blondet, Eric; Faidy, Claude

    2002-07-01

    Different fatigue-related incidents which occurred in the world on the auxiliary lines of the reactor coolant system (SIS, RHR, CVC) have led EDF to search solutions in order to avoid or to limit consequences of thermodynamic phenomenal (Farley-Tihange, free convection loop and stratification, independent thermal cycling). Studies are performed on mock-up and compared with instrumentation on nuclear power stations. At the present time, studies allow EDF to carry out pipe modifications and to prepare specifications and recommendations for next generation of nuclear power plants. In 1998, a new phenomenal appeared on RHR system in Civaux. A crack was discovered in an area where hot and cold fluids (temperature difference of 140 deg. C) were mixed. Metallurgic studies concluded that this crack was caused by high cycle thermal fatigue. Since 1998, EDF is making an inventory of all mixing areas in French PWR on basis of criteria. For all identified areas, a method was developed to improve the first classifying and to keep back only potential damage pipes. Presently, studies are performing on the charging line nozzle connected to the reactor pressure vessel. In order to evaluate the load history, a mock-up has been developed and mechanical calculations are realised on this nozzle. The paper will make an overview of EDF conclusions on these different points: - dead legs and vortex in a no flow connected line; - stratification; - mixing tees with high {delta}T. (authors)

  19. Interannual Variability in FPAR and NPP across California's Ecosystems

    NASA Astrophysics Data System (ADS)

    Jin, Y.; Goulden, M. L.; Randerson, J. T.

    2005-12-01

    Quantifying the response of ecosystems to climate is particularly important for understanding California's regional carbon budget because of large year-to-year changes in precipitation and because of large changes in temperature and precipitation that are predicted to occur across the western U.S. during the 21st century. Here, we examined how net primary production (NPP) varies with precipitation and how this ecosystem process contributes to the changes in carbon storage on interannual timescales. We used FPAR derived from NOAA AVHRR satellite observations during 1982-2003 and from MODIS observations during 2000-2005 as inputs to the CASA biogeochemical model. We found that mean annual integrals of NDVI, FPAR, and NPP were closely linked with mean annual precipitation levels across the state. The sensitivity of NPP to interannual variability in precipitation depended on ecosystem type. Desert shrub and grassland ecosystems responded the most to interannual changes in precipitation, whereas forests showed little or no response. In semiarid ecosystems, the site-level temporal sensitivity of NPP to variations in precipitation was found to be lower than the sensitivity of NPP to precipitation derived from a spatial model, suggesting that other constraints such as plant structure or nitrogen availability may limit NPP responses to short-term precipitation transients.

  20. Influence Of Low Boron Core Design On PWR Transient Behavior

    SciTech Connect

    Aleksandrov Papukchiev, Angel; Yubo Liu; Schaefer, Anselm

    2006-07-01

    In conventional pressurized water reactor (PWR) designs, the concentration of boron in primary coolant is limited by the requirement of having a negative moderator density coefficient. As high boron concentrations have significant impact on reactivity feedback properties, design changes to reduce boron concentration in the reactor coolant are of general interest in view of improving PWR inherent safety. In the framework of an investigation into the feasibility of low boron design, a PWR core configuration based on fuel with higher gadolinium (Gd) content has been developed which permits to reduce the natural boron concentration at begin of cycle (BOC) by approx. 50% compared to current German PWR technology. For the assessment of the potential safety advantages, a Loss-of-Feedwater Anticipated Transient Without Scram (ATWS LOFW) has been simulated with the system code ATHLET for two PWR core designs: a low boron design and a standard core design. The most significant difference in the transient performance of both designs is the total primary fluid mass released through the pressurizer (PRZ) valves. It is reduced by a factor of four for the low boron reactor, indicating its improved density reactivity feedback. (authors)

  1. Timing analysis of PWR fuel pin failures

    SciTech Connect

    Jones, K.R.; Wade, N.L.; Katsma, K.R.; Siefken, L.J. ); Straka, M. )

    1992-09-01

    This report discusses research conducted to develop and demonstrate a methodology for calculation of the time interval between receipt of the containment isolation signals and the first fuel pin failure for loss-of-coolant accidents (LOCAs). Demonstration calculations were performed for a Babcock and Wilcox (B W) design (Oconee) and a Westinghouse (W) four-loop design (Seabrook). Sensitivity studies were performed to assess the impacts of fuel pin burnup, axial peaking factor, break size, emergency core cooling system availability, and main coolant pump trip on these times. The analysis was performed using the following codes: FRAPCON-2, for the calculation of steady-state fuel behavior; SCDAP/RELAP5/MOD3 and TRACPF1/MOD1, for the calculation of the transient thermal-hydraulic conditions in the reactor system; and FRAP-T6, for the calculation of transient fuel behavior. In addition to the calculation of fuel pin failure timing, this analysis provides a comparison of the predicted results of SCDAP/RELAP5/MOD3 and TRAC-PF1/MOD1 for large-break LOCA analysis. Using SCDAP/RELAP5/MOD3 thermal-hydraulic data, the shortest time intervals calculated between initiation of containment isolation and fuel pin failure are 10.4 seconds and 19.1 seconds for the B W and W plants, respectively. Using data generated by TRAC-PF1/MOD1, the shortest intervals are 10.3 seconds and 29.1 seconds for the B W and W plants, respectively. These intervals are for a double-ended, offset-shear, cold leg break, using the technical specification maximum peaking factor and applied to fuel with maximum design burnup. Using peaking factors commensurate with actual burnups would result in longer intervals for both reactor designs. This document provides appendices K and L of this report which provide plots for the timing analysis of PWR fuel pin failures for Oconee and Seabrook respectively.

  2. Lessons learnt from Ignalina NPP decommissioning project

    SciTech Connect

    NAISSE, Jean-Claude

    2007-07-01

    The Ignalina Nuclear Power Plant (INPP) is located in Lithuania, 130 km north of Vilnius, and consists of two 1500 MWe RBMK type units, commissioned respectively in December 1983 and August 1987. On the 1. of May 2004, the Republic of Lithuania became a member of the European Union. With the protocol on the Ignalina Nuclear Power in Lithuania which is annexed to the Accession Treaty, the Contracting Parties have agreed: - On Lithuanian side, to commit closure of unit 1 of INPP before 2005 and of Unit 2 by 31 December 2009; - On European Union side, to provide adequate additional Community assistance to the efforts of Lithuania to decommission INPP. The paper is divided in two parts. The first part describes how, starting from this agreement, the project was launched and organized, what is its present status and which activities are planned to reach the final ambitious objective of a green field. To give a global picture, the content of the different projects that were defined and the licensing process will also be presented. In the second part, the paper will focus on the lessons learnt. It will explain the difficulties encountered to define the decommissioning strategy, considering both immediate or differed dismantling options and why the first option was finally selected. The paper will mention other challenges and problems that the different actors of the project faced and how they were managed and solved. The paper will be written by representatives of the Ignalina NPP and of the Project Management Unit. (author)

  3. Moisture Separator Reheater for NPP Turbines

    NASA Astrophysics Data System (ADS)

    Manabe, Jun; Kasahara, Jiro

    This paper introduces the development of the current model Moisture Separator Reheater (MSR) for nuclear power plant (NPP) turbines, commercially placed in service in the period 1984-1997, focusing on the mist separation performance of the MSR along with drainage from heat exchanger tubes. A method of predicting the mist separation performance was devised first based on the observation of mist separation behaviors under an air-water test. Then the method was developed for the application to predict under the steam conditions, followed by the verification in comparison with the actual results of a steam condition test. The instability of tube drainage associated with both sub-cooling and temperature oscillation might adversely affect the seal welding of tubes to tube sheet due to thermal fatigue. The instability was measured on an existing unit to clarify behaviors and the development of a method to suppress them. Both methods were applied to newly constructed units and the effectiveness of the methods was demonstrated.

  4. Fire Risk Analysis for Armenian NPP Confinement

    SciTech Connect

    Poghosyan, Shahen; Malkhasyan, Albert; Bznuni, Surik; Amirjanyan, Armen

    2006-07-01

    Major fire occurred at Armenian NPP (ANPP) in October 1982 showed that fire-induced initiating events (IE) can have dominant contribution in overall risk of core damage. Probabilistic Safety Assessment study for fire-induced initiating events for ANPP was initiated in 2002. Analysis was performed for compartments fires in which could result in failure of components which are necessary for reactor cold shutdown. Analysis shows that main risk from fire at ANPP is conditioned by fire in cable tunnels 61-64. Meanwhile fire in confinement compartments don't have significant contribution to overall risk of core damage. The exception is so called 'confinement valves compartment' (room no.A-013/2) fire (more than 7.5% of CDF) in which fire could result in the loss of coolant accident with unavailability of primary makeup system, which directly leads to core damage. Detailed analysis of this problem that is common for typical WWER-440/230 reactors with no hermetic MCPs and recommendations for solution are presented in this paper. (authors)

  5. Leak before break application in French PWR plants under operation

    SciTech Connect

    Faidy, C.

    1997-04-01

    Practical applications of the leak-before break concept are presently limited in French Pressurized Water Reactors (PWR) compared to Fast Breeder Reactors. Neithertheless, different fracture mechanic demonstrations have been done on different primary, auxiliary and secondary PWR piping systems based on similar requirements that the American NUREG 1061 specifications. The consequences of the success in different demonstrations are still in discussion to be included in the global safety assessment of the plants, such as the consequences on in-service inspections, leak detection systems, support optimization,.... A large research and development program, realized in different co-operative agreements, completes the general approach.

  6. Sensitivity of risk parameters to human errors for a PWR

    SciTech Connect

    Samanta, P.; Hall, R. E.; Kerr, W.

    1980-01-01

    Sensitivities of the risk parameters, emergency safety system unavailabilities, accident sequence probabilities, release category probabilities and core melt probability were investigated for changes in the human error rates within the general methodological framework of the Reactor Safety Study for a Pressurized Water Reactor (PWR). Impact of individual human errors were assessed both in terms of their structural importance to core melt and reliability importance on core melt probability. The Human Error Sensitivity Assessment of a PWR (HESAP) computer code was written for the purpose of this study.

  7. Enriched boric acid for PWR application: Cost evaluation study for a twin-unit PWR

    SciTech Connect

    Battaglia, J.A.; Waters, R.M.; von Hollen, J.M.; Lamatia, L.A.; Bergmann, C.A.; Ditommaso, S.M. . Nuclear and Advanced Technology Div.)

    1989-09-01

    In the nuclear industry boric acid dissolved in the reactor coolant is used as a soluble reactivity control agent. Reactivity control in nuclear plants is also provided by neutron absorbing control rods. This neutron absorbing duty is distributed between the control rods and soluble boric acid in such a way as to provide the most economical split. Typically, the control rods take care of rapid reactivity changes and the boric acid handles the slower long term control of reactivity by varying the boric acid concentrations within the reactor coolant. In PWR reactor plants the dissolved boric acid is referred to as a soluble poison or chemical shim due to the high capacity for thermal neutron capture exhibited by the boron-10 isotope contained in the boric acid molecule. This slow reactivity change or chemical shim control would otherwise have to be performed using control rods, a much more expensive proposition. Reactivity changes are controlled by the B-10 isotope by virtue of its very high cross section (3837 barns) for thermal neutron absorption. However, natural boron contains only 20 atom percent of the B-10 isotope and essentially all the remaining 80 percent as the B-11 isotope. The B-11 isotope of cross section .005 barns is essentially of no use as a neutron absorber. Since B-11 makes up the bulk of the total boron present and contributes little to the nuclear operation it would seem logical to eliminate this isotope of boron from the boric acid molecule. In so doing boric acid concentration in operating PWR plants need only be a fraction of that existing to accomplish identical nuclear operations. However, to achieve the elimination of B-11 from NBA (Natural Boric Acid) an isotope separation must be performed. 4 refs., 25 figs., 17 tabs.

  8. Method of characteristics - Based sensitivity calculations for international PWR benchmark

    SciTech Connect

    Suslov, I. R.; Tormyshev, I. V.; Komlev, O. G.

    2013-07-01

    Method to calculate sensitivity of fractional-linear neutron flux functionals to transport equation coefficients is proposed. Implementation of the method on the basis of MOC code MCCG3D is developed. Sensitivity calculations for fission intensity for international PWR benchmark are performed. (authors)

  9. Comparison of Removed Fuel Compositions of CANDLE, PWR, and FBR

    SciTech Connect

    Nagata, Akito; Sekimoto, Hiroshi

    2007-07-01

    A new reactor burnup strategy CANDLE was proposed, where shapes of neutron flux, nuclide densities and power density distributions remain constant but move to an axial direction. Application of this burnup strategy to neutron rich fast reactors makes excellent performances. Only natural or depleted uranium is required for the replaced fresh fuels. About 40% of natural or depleted uranium undergoes fission. In this paper, spent fuels of PWR, FBR and CANDLE reactor are compared. Fresh fuels of PWR, FBR and CANDLE reactor are 4.1% enriched uranium (UO{sub 2}), MOX with 18.5% plutonium enrichment and natural uranium nitride (natural-UN), respectively. In once-through fuel cycle point of view, low disposal amount for high energy is better and CANDLE reactor can decrease this amount more than other reactors, especially it is only one-tenth of PWR fuel. Also, it can decrease MA and this amount is 0.4 times of PWR. Total FP amount of each reactor is nearly same. However, LLFP amount of CANDLE reactor is the largest. (authors)

  10. Modeling and statistical analysis of feedback between NPP (MODIS NPP) and temperature for forest area Yenisei River

    NASA Astrophysics Data System (ADS)

    Kukoba, Nikolay; Ivanova, Yulia; Saltykov, Mikhail

    Assimilation of carbon by green plants or net primary production (NPP) is one of the most important processes. It provide qualitative and quantitative estimates of the events occurring in the biosphere. Carbon assimilated by plants is used by them to increase their biomass and is a main process of food chains on Earth. NPP is highly variable in time and space. It may depend on physical factors such as temperature, humidity and concentration of nutrients in the soil, etc. And also depends on the types of vegetation (woody, herbaceous, coniferous, and deciduous, etc.). In this regard, it is very important to understand what kind of climate factor is a limiting factor of NPP in the given time and place. For this aim a statistical analysis of the feedback between NPP (MODIS NPP) and the temperature of the forest zone Yenisey River has been performed. We used the time series of NPP for studied territory between 2000 and 2012. The time series of temperature were calculated using the data from the satellite measurements (MODISTERRA) and the global network of weather stations. The considered territory is situated in the Yenisey River basin with diverse natural landscapes - from forest-tundra in the North to alpine meadows in the West Sayan Mountains in the South. This territory extends along the Yenisey River from north to south for about 2000 km. Plains and mountainous areas have been investigated separately. Mountain forests are located in the West Sayan and altitudinal zonation varies from 500 to 2000 m a.s.l. In order to investigate the causal relationships between temperature and NPP we applied the method of Convergent Cross-Mapping (CCM) (Sugihara et al., Science. 2012. V. 338. P. 496-500). This method in some case allows to determine what is a reason and what is consequence, that cannot be definded by simple correlation. It has been shown that the best results are obtained for the 8 -day composite satellite data during the growing season (MOD17A2, MOD11A2). By means

  11. Validation of MCNP NPP Activation Simulations for Decommissioning Studies by Analysis of NPP Neutron Activation Foil Measurement Campaigns

    NASA Astrophysics Data System (ADS)

    Volmert, Ben; Pantelias, Manuel; Mutnuru, R. K.; Neukaeter, Erwin; Bitterli, Beat

    2016-02-01

    In this paper, an overview of the Swiss Nuclear Power Plant (NPP) activation methodology is presented and the work towards its validation by in-situ NPP foil irradiation campaigns is outlined. Nuclear Research and consultancy Group (NRG) in The Netherlands has been given the task of performing the corresponding neutron metrology. For this purpose, small Aluminium boxes containing a set of circular-shaped neutron activation foils have been prepared. After being irradiated for one complete reactor cycle, the sets have been successfully retrieved, followed by gamma-spectrometric measurements of the individual foils at NRG. Along with the individual activities of the foils, the reaction rates and thermal, intermediate and fast neutron fluence rates at the foil locations have been determined. These determinations include appropriate corrections for gamma self-absorption and neutron self-shielding as well as corresponding measurement uncertainties. The comparison of the NPP Monte Carlo calculations with the results of the foil measurements is done by using an individual generic MCNP model functioning as an interface and allowing the simulation of individual foil activation by predetermined neutron spectra. To summarize, the comparison between calculation and measurement serve as a sound validation of the Swiss NPP activation methodology by demonstrating a satisfying agreement between measurement and calculation. Finally, the validation offers a chance for further improvements of the existing NPP models by ensuing calibration and/or modelling optimizations for key components and structures.

  12. Multi-scale evaluation of ISIMIP biome models against NDVI and MODIS NPP data

    NASA Astrophysics Data System (ADS)

    Rafique, Rashad; Zhao, Fang; Zeng, Ning; Asrar, Ghassem; Reyer, Christopher; Ostberg, Sebastian; Francois, Louis; Tian, Hanqin; Chnag, Jinfeng; Nishina, Kazuya

    2016-04-01

    The net primary productivity (NPP) is commonly used for understanding the dynamics of terrestrial ecosystems and their role in carbon cycle. The global NPP, highly variable over space and time, cannot be directly observed, therefore, satellite based observations of Normalized Difference Vegetation Index (NDVI) are used as a proxy to understand and monitor the NPP dynamics. In this study, we used a combination of most recent NDVI and modeled NPP data for the period 1982-2012, to study the role of terrestrial ecosystems in carbon cycle under the prevailing climate conditions. We found that in general there is good agreement between the spatial patterns and global seasonal cycles between observed NDVI and modeled NPP values. Simulated NPP values also generally agree with MODIS NPP spatially, and temporally, MODIS NPP falls within the model spread of NPP values. Despite of the general agreement in the trends of global total NDVI, MODIS NPP and modeled NPP, considerable spatial differences are found, and the ensemble mean of the models often agrees better with the spatial patterns of observed NDVI and MODIS NPP than individual models.

  13. Suomi NPP VIIRS Ocean Color Data Product Early Mission Assessment

    NASA Technical Reports Server (NTRS)

    Turpie, Kevin R.; Robinson, Wayne D.; Franz, Bryan A.; Eplee, Robert E., Jr.; Meister, Gerhard; Fireman, Gwyn F.; Patt, Frederick S.; Barnes, Robert A.; McClain, Charles R.

    2013-01-01

    Following the launch of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polarorbiting Partnership (NPP) spacecraft, the NASA NPP VIIRS Ocean Science Team (VOST) began an evaluation of ocean color data products to determine whether they could continue the existing NASA ocean color climate data record (CDR). The VOST developed an independent evaluation product based on NASA algorithms with a reprocessing capability. Here we present a preliminary assessment of both the operational ocean color data products and the NASA evaluation data products regarding their applicability to NASA science objectives.

  14. NPOESS Preparatory Project (NPP) Environmental Products

    NASA Astrophysics Data System (ADS)

    Grant, K. D.; Smith, D. C.

    2011-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will contribute the afternoon orbit component and ground processing system of the restructured National Polar-orbiting Operational Environmental Satellite System (NPOESS). As such, the Joint Polar Satellite System replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the ground processing component of both POES and the Defense Meteorological Satellite Program (DMSP) replacement, known as the Defense Weather Satellite System (DWSS), managed by the Department of Defense (DoD). The Joint Polar Satellite System satellite will carry a suite of sensors designed to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground processing system for the Joint Polar Satellite System is known as the Common Ground System (JPSS CGS), and consists of a Command, Control, and Communications Segment (C3S) and the Interface Data Processing Segment (IDPS). Both are developed by Raytheon Intelligence and Information Systems (IIS). The Interface Data Processing Segment will process Joint Polar Satellite System and Defense Weather Satellite System satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to the National Oceanic and Atmospheric Administration and Department of Defense processing centers operated by the United States government. The Interface Data Processing Segment will process Environmental Data Records beginning with the NPOESS Preparatory Project (NPP) and continue through the lifetime of the Joint Polar Satellite System and Defense Weather Satellite System programs. Under the National Polar-orbiting Operational Environmental

  15. Radioactive Spent Ion-Exchange Resins Conditioning by the Hot Supercompaction Process at Tihange NPP - Early Experience - 12200

    SciTech Connect

    Braet, Johan; Charpentier, David; Centner, Baudouin; Vanderperre, Serge

    2012-07-01

    Spent ion-exchange resins are considered to be problematic waste that, in many cases, requires special approaches and precautions during their conditioning to meet the acceptance criteria for disposal. In Belgium, for economical reasons, the Volume Reduction Factor is a key criterion. After Tractebel Engineering performed a technical and economical comparison of the industrially available systems, Tihange NPP decided to install a spent ion-exchange resins hot supercompaction unit with Tractebel Engineering in the role of architect-engineer. The treatment and conditioning unit processes the spent ion-exchange resins through the following steps: dewatering of the resins, drying the resins under deep vacuum, discharging the dried resins into compactable drums, super-compacting the drums to generate pellets, grouting the pellets into standard 400 litres waste drums (overpacks) licensed for final disposal in the near-surface repository in Belgium. Several developments were required to adapt the reference process and equipment to PWR spent ion-exchange bead resins and Belgian radioactive waste acceptance criteria. In order to avoid cracks on the compacted drum, and external surface contamination from resin leaks, some improvements were achieved to minimize spring-back as well as the risk of cracking the drum wall. Placing the compactable drum inside a second, slightly larger drum, guarantees clean and reproducible pellets. Currently the commissioning phase is on-going. Numerous process validation tests have been completed. An acceptance file was transmitted to the Belgian Waste Management Authority recently. This will be followed by demonstration tests necessary to obtain their final acceptance of the installation. More than 3 800 drums of mixed powdered and bead resins have been processed by the reference Hot Compaction process, achieving a Volume Reduction Factor (VRF) of 2.5. The equipment has been proven to be a reliable technology with low operation and maintenance

  16. The Chernobyl NPP decommissioning: Current status and alternatives

    SciTech Connect

    Mikolaitchouk, H.; Steinberg, N.

    1996-08-01

    After the Chernobyl accident of April 26, 1986, many contradictory decisions were taken concerning the Chernobyl nuclear power plant (NPP) future. The principal source of contradictions was a deadline for a final shutdown of the Chernobyl NPP units. Alterations in a political and socioeconomic environment resulted in the latest decision of the Ukrainian Authorities about 2000 as a deadline for a beginning of the Chernobyl NPP decommissioning. The date seems a sound compromise among the parties concerned. However, in order to meet the data a lot of work should be done. First of all, a decommissioning strategy has to be established. The problem is complicated due to both site-specific aspects and an absence of proven solutions for the RBMK-type reactor decommissioning. In the paper the problem of decommissioning option selection is considered taking into account an influence of the following factors: relevant legislative and regulatory requirements; resources required to carry out decommissioning (man-power, equipment, technologies, waste management infrastructure, etc.); radiological and physical status of the plant, including structural integrity and predictable age and weather effects; impact of planned activities at the destroyed unit 4 and within the 30-km exclusion zone of the Chernobyl NPP; planed use of the site; socio-economic considerations.

  17. Software to Compare NPP HDF5 Data Files

    NASA Technical Reports Server (NTRS)

    Wiegand, Chiu P.; LeMoigne-Stewart, Jacqueline; Ruley, LaMont T.

    2013-01-01

    This software was developed for the NPOESS (National Polar-orbiting Operational Environmental Satellite System) Preparatory Project (NPP) Science Data Segment. The purpose of this software is to compare HDF5 (Hierarchical Data Format) files specific to NPP and report whether the HDF5 files are identical. If the HDF5 files are different, users have the option of printing out the list of differences in the HDF5 data files. The user provides paths to two directories containing a list of HDF5 files to compare. The tool would select matching HDF5 file names from the two directories and run the comparison on each file. The user can also select from three levels of detail. Level 0 is the basic level, which simply states whether the files match or not. Level 1 is the intermediate level, which lists the differences between the files. Level 2 lists all the details regarding the comparison, such as which objects were compared, and how and where they are different. The HDF5 tool is written specifically for the NPP project. As such, it ignores certain attributes (such as creation_date, creation_ time, etc.) in the HDF5 files. This is because even though two HDF5 files could represent exactly the same granule, if they are created at different times, the creation date and time would be different. This tool is smart enough to ignore differences that are not relevant to NPP users.

  18. Nuclear Power Plant Module, NPP-1: Nuclear Power Cost Analysis.

    ERIC Educational Resources Information Center

    Whitelaw, Robert L.

    The purpose of the Nuclear Power Plant Modules, NPP-1, is to determine the total cost of electricity from a nuclear power plant in terms of all the components contributing to cost. The plan of analysis is in five parts: (1) general formulation of the cost equation; (2) capital cost and fixed charges thereon; (3) operational cost for labor,…

  19. Nonhydrolyzable ATP analogues as selective inhibitors of human NPP1: a combined computational/experimental study.

    PubMed

    Lecka, Joanna; Ben-David, Gal; Simhaev, Luba; Eliahu, Shay; Oscar, Jocelyn; Luyindula, Patrick; Pelletier, Julie; Fischer, Bilha; Senderowitz, Hanoch; Sévigny, Jean

    2013-11-14

    Elevated nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) activity is implicated in health disorders including pathological calcification. Specific NPP1 inhibitors would therefore be valuable for studying this enzyme and as potential therapeutic agents. Here we present a combined computational/experimental study characterizing 13 nonhydrolyzable ATP analogues as selective human NPP1 inhibitors. All analogues at 100 μM inhibited (66-99%) the hydrolysis of pnp-TMP by both recombinant NPP1 and cell surface NPP1 activity of osteocarcinoma (HTB-85) cells. These analogues only slightly altered the activity of other ectonucleotidases, NPP3 and NTPDases. The Ki,app values of the seven most potent and selective inhibitors were in the range of 0.5-56 μM, all with mixed type inhibition, predominantly competitive. Those molecules were docked into a newly developed homology model of human NPP1. All adopted ATP-like binding modes, suggesting competitive inhibition with the endogenous ligand. NPP1 selectivity versus NPP3 could be explained in terms of the electrostatic potential of the two proteins that of NPP1 favoring negatively charged ligands. Inhibitor 2 that had the lowest Ki,app (0.5 μM) was also inactive toward P2Y receptors. Overall, analogue 2 is the most potent and selective NPP1 inhibitor described so far. PMID:24083941

  20. Robotic inspection of PWR coolant pump casing welds

    SciTech Connect

    Pratt, W.R.; Alford, J.W.; Davis, J.B.

    1997-12-01

    As of January 1, 1995, the Swedish Nuclear Inspectorate began requiring more thorough inspections of cast stainless-steel components in nuclear power plants, including pressurized water reactor (PWR) reactor coolant pump (RCP) casings. The examination requirements are established by fracture mechanics analyses of component weldments and demonstrated test system detection capabilities. This may include full volumetric inspection or some portion thereof. Ringhals station is a four-unit nuclear power plant, owned and operated by the Swedish State Power Board, Vattenfall. Unit 1 is a boiling water reactor. Units 2, 3, and 4 are Westinghouse-designed PWRs, ranging in size from 795 to 925 MW. The RCP casings at the PWR units are made of cast stainless steel and contain four circumferential welds that require inspection. Due to the thickness of the casings at the weld locations and configuration and surface conditions on the outside diameter of the casings, remote inspection from the inside diameter of the pump casing was mandated.

  1. FLUOLE-2: An Experiment for PWR Pressure Vessel Surveillance

    NASA Astrophysics Data System (ADS)

    Thiollay, Nicolas; Di Salvo, Jacques; Sandrin, Charlotte; Soldevila, Michel; Bourganel, Stéphane; Fausser, Clément; Destouches, Christophe; Blaise, Patrick; Domergue, Christophe; Philibert, Hervé; Bonora, Jonathan; Gruel, Adrien; Geslot, Benoit; Lamirand, Vincent; Pepino, Alexandra; Roche, Alain; Méplan, Olivier; Ramdhane, Mourad

    2016-02-01

    FLUOLE-2 is a benchmark-type experiment dedicated to 900 and 1450 MWe PWR vessels surveillance dosimetry. This two-year program started in 2014 and will end in 2015. It will provide precise experimental data for the validation of the neutron spectrum propagation calculation from core to vessel. It is composed of a square core surrounded by a stainless steel baffe and internals: PWR barrel is simulated by steel structures leading to different steel-water slides; two steel components stand for a surveillance capsule holder and for a part of the pressure vessel. Measurement locations are available on the whole experimental structure. The experimental knowledge of core sources will be obtained by integral gamma scanning measurements directly on fuel pins. Reaction rates measured by calibrated fission chambers and a large set of dosimeters will give information on the neutron energy and spatial distributions. Due to the low level neutron flux of EOLE ZPR a special, high efficiency, calibrated gamma spectrometry device will be used for some dosimeters, allowing to measure an activity as low as 7. 10-2 Bq per sample. 103mRh activities will be measured on an absolute calibrated X spectrometry device. FLUOLE-2 experiment goal is to usefully complete the current experimental benchmarks database used for the validation of neutron calculation codes. This two-year program completes the initial FLUOLE program held in 2006-2007 in a geometry representative of 1300 MWe PWR.

  2. Design study of long-life PWR using thorium cycle

    NASA Astrophysics Data System (ADS)

    Subkhi, Moh. Nurul; Su'ud, Zaki; Waris, Abdul

    2012-06-01

    Design study of long-life Pressurized Water Reactor (PWR) using thorium cycle has been performed. Thorium cycle in general has higher conversion ratio in the thermal spectrum domain than uranium cycle. Cell calculation, Burn-up and multigroup diffusion calculation was performed by PIJ-CITATION-SRAC code using libraries based on JENDL 3.2. The neutronic analysis result of infinite cell calculation shows that 231Pa better than 237Np as burnable poisons in thorium fuel system. Thorium oxide system with 8% 233U enrichment and 7.6˜ 8% 231Pa is the most suitable fuel for small-long life PWR core because it gives reactivity swing less than 1% Δk/k and longer burn up period (more than 20 year). By using this result, small long-life PWR core can be designed for long time operation with reduced excess reactivity as low as 0.53% Δk/k and reduced power peaking during its operation.

  3. Design study of long-life PWR using thorium cycle

    SciTech Connect

    Subkhi, Moh. Nurul; Su'ud, Zaki; Waris, Abdul

    2012-06-06

    Design study of long-life Pressurized Water Reactor (PWR) using thorium cycle has been performed. Thorium cycle in general has higher conversion ratio in the thermal spectrum domain than uranium cycle. Cell calculation, Burn-up and multigroup diffusion calculation was performed by PIJ-CITATION-SRAC code using libraries based on JENDL 3.2. The neutronic analysis result of infinite cell calculation shows that {sup 231}Pa better than {sup 237}Np as burnable poisons in thorium fuel system. Thorium oxide system with 8%{sup 233}U enrichment and 7.6{approx} 8%{sup 231}Pa is the most suitable fuel for small-long life PWR core because it gives reactivity swing less than 1%{Delta}k/k and longer burn up period (more than 20 year). By using this result, small long-life PWR core can be designed for long time operation with reduced excess reactivity as low as 0.53%{Delta}k/k and reduced power peaking during its operation.

  4. PWR Cross Section Libraries for ORIGEN-ARP

    SciTech Connect

    McGraw, Carolyn; Ilas, Germina

    2012-01-01

    New pressurized water reactor (PWR) cross-section libraries were generated for use with the ORIGEN-ARP depletion sequence in the SCALE nuclear analysis code system. These libraries are based on ENDF/B-VII nuclear data and were generated using the two-dimensional depletion sequence, TRITON/NEWT, in SCALE 6.1. The libraries contain multiple burnup-dependent cross-sections for seven PWR fuel designs, with enrichments ranging from 1.5 to 6 wt% 235U. The burnup range has been extended from the 72 GWd/MTU used in previous versions of the libraries to 90 GWd/MTU. Validation of the libraries using radiochemical assay measurements and decay heat measurements for PWR spent fuel showed good agreement between calculated and experimental data. Verification against detailed TRITON simulations for the considered assembly designs showed that depletion calculations performed in ORIGEN-ARP with the pre-generated libraries provide similar results as obtained with direct TRITON depletion, while greatly reducing the computation time.

  5. Mapping and analysing cropland use intensity from a NPP perspective

    NASA Astrophysics Data System (ADS)

    Niedertscheider, Maria; Kastner, Thomas; Fetzel, Tamara; Haberl, Helmut; Kroisleitner, Christine; Plutzar, Christoph; Erb, Karl-Heinz

    2016-01-01

    Meeting expected surges in global biomass demand while protecting pristine ecosystems likely requires intensification of current croplands. Yet many uncertainties relate to the potentials for cropland intensification, mainly because conceptualizing and measuring land use intensity is intricate, particularly at the global scale. We present a spatially explicit analysis of global cropland use intensity, following an ecological energy flow perspective. We analyze (a) changes of net primary production (NPP) from the potential system (i.e. assuming undisturbed vegetation) to croplands around 2000 and relate these changes to (b) inputs of (N) fertilizer and irrigation and (c) to biomass outputs, allowing for a three dimensional focus on intensification. Globally the actual NPP of croplands, expressed as per cent of their potential NPP (NPPact%), amounts to 77%. A mix of socio-economic and natural factors explains the high spatial variation which ranges from 22.6% to 416.0% within the inner 95 percentiles. NPPact% is well below NPPpot in many developing, (Sub-) Tropical regions, while it massively surpasses NPPpot on irrigated drylands and in many industrialized temperate regions. The interrelations of NPP losses (i.e. the difference between NPPact and NPPpot), agricultural inputs and biomass harvest differ substantially between biogeographical regions. Maintaining NPPpot was particularly N-intensive in forest biomes, as compared to cropland in natural grassland biomes. However, much higher levels of biomass harvest occur in forest biomes. We show that fertilization loads correlate with NPPact% linearly, but the relation gets increasingly blurred beyond a level of 125 kgN ha-1. Thus, large potentials exist to improve N-efficiency at the global scale, as only 10% of global croplands are above this level. Reallocating surplus N could substantially reduce NPP losses by up to 80% below current levels and at the same time increase biomass harvest by almost 30%. However, we

  6. Performance of the NPP CrIS Sensor

    NASA Astrophysics Data System (ADS)

    Emch, P. G.; Farrow, S. V.; Gu, D.; Wang, C.; Hagan, D. E.; Sabet-Peyman, F.

    2009-12-01

    This paper discusses the performance of the first Cross-track Infrared Sounder (CrIS) flight instrument and its data product performance. Together with ATMS, the CrIS sensor is a critical payload for National Polar-orbiting Operational Environmental Satellite System (NPOESS) providing temperature and moisture profiles, and will first fly on the NPOESS Preparatory Project (NPP) mission, the risk reduction flight for NPOESS. NPOESS is the next generation weather and climate monitoring system for the Department of Defense and National Oceanic and Atmospheric Administration (NOAA), being developed under contract by Northrop Grumman Aerospace Systems. The NPP flight sensor has recently completed thermal vacuum, electro-magnetic interference, and vibration testing. By the time of the presentation, the sensor sell-off is expected to have been completed as well. An overview of the sensor, the FM1 measurement performance, and details of the retrieval algorithms will be provided in this presentation.

  7. Novel technology for hydrothermal treatment of NPP evaporator concentrates

    SciTech Connect

    Avramenko, Valentin; Dobrzhansky, Vitaly; Marinin, Dmitry; Sergienko, Valentin; Shmatko, Sergey

    2007-07-01

    A novel technology was developed for treatment of evaporator concentrates produced as a result of operation of evaporation devices comprising the main component of special water purification systems of nuclear power plants (NPP). The developed technology includes a hydrothermal (T=250-300 deg. C and P=80-120 bar) processing of evaporator concentrates in oxidation medium in order to destruct stable organic complexes of cobalt radionuclides and remove these radionuclides by oxide materials formed during such a processing. The cesium radionuclides contained in evaporator concentrates are removed by a conventional method-through application of one of the developed composite sorbents with ferrocyanides of transition metals used as active agents. Extensive laboratory studies of the processes occurring in evaporator concentrates under hydrothermal conditions were performed. It was shown that hydrothermal oxidation of evaporator concentrates has a number of advantages as compared to traditional oxidation methods (ozonization, photo-catalytic, electrochemical and plasma oxidation). A laboratory installation was built for the flow-type hydrothermal oxidation of NPP evaporator concentrates. The obtained experimental results showed good prospects for the developed method application. On the basis of the results obtained, a pilot installation of productivity up to 15 l/hour was developed and built in order to work out the technology of evaporator concentrates hydrothermal treatment. The pilot tests of the hydrothermal technology for evaporator concentrates hydrothermal treatment were performed for 6 months in 2006 at the 1. reactor unit of the Novovoronezhskaya NPP (Voronezh Region, Russia). Optimal technological regimes were determined, and estimations of the economic soundness of the technology were made. The advantages of the presented technology in terms of management of concentrated liquid radioactive wastes (LRW) at nuclear cycle facilities, as compared to other methods

  8. Radioecological Investigations of the Area around the Belene NPP

    SciTech Connect

    Hristov, Hr.; Balabanov, N.; Marinova, S.; Zaprianova, P.; Nedeva, P.; Blagoeva, E.; Philipov, M.; Gustova, M.; Maslov, O.

    2010-01-21

    The report presents the results from research of contents of U and Th in soil samples from the region of the Belene Nuclear Power Plant (NPP). The report presents the investigations for sorption of U in the system soil-water from region. The report presents similarly the results for the natural radiation background--about 0,14 muSv/h, for the investigated region.

  9. Modular vault dry storage at Paks NPP technology and experience

    SciTech Connect

    Bower, C.C.F.; Szabo, B.

    1995-12-31

    Paks NPP in Hungary, with its four VVER440 reactors, generates 50% of Hungary`s electricity. In 1990, it was faced with an uncertain future due to the changing political situation in Eastern Europe. The fuel storage ponds were rapidly filling up, with no secure route for disposal. The paper outlines the Paks approach to resolving the problem and the background to its chosen solution, concluding with a review of the experience of other applications of the system.

  10. Preparation for Early Termination of Ignalina NPP Operation

    SciTech Connect

    Poskas, P.; Poskas, R.

    2003-02-26

    Seimas (Parliament of Lithuania) approved updated National Energy strategy where it is indicated that first Unit will be shutdown before the year 2005 and second Unit in 2009 if funding for decommissioning is available from EU and other donors. In accordance to Ignalina NPP Unit 1 Closure Law the Government of Lithuania approved the Ignalina NPP Unit 1 Decommissioning Program until year 2005. For enforcement of this program, the plan of measures for implementation of the program was prepared and approved by the Minister of Economy. The plan consists of two parts, namely technical- environmental and social-economic. Technical-environmental measures are mostly oriented to the safe management of spent nuclear fuel and operational radioactive waste stored at the plant and preparation of licensing documents for Unit 1 decommissioning. Social-economic measures are oriented to mitigate negative social and economic impact on Lithuania, inhabitants of the region, and, particularly, o n the staff of Ignalina NPP by means of creating favorable conditions for a balanced social and economic development of the region. In this paper analysis of planned activities, licensing requirements for decommissioning, progress in preparation of the Final Decommissioning Plan is discussed.

  11. ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase

    Energy Science and Technology Software Center (ESTSC)

    2013-11-01

    1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These maymore » be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69 rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section

  12. ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase

    SciTech Connect

    2013-11-01

    1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These may be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69 rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section, similar in

  13. Integrating the Clearance in NPP Residual Material Management

    SciTech Connect

    Garcia-Bermejo, R.; Lamela, B.

    2008-01-15

    Previous Experiences in decommissioning projects are being used to optimize the residual material management in NPP, metallic scrap usually. The approach is based in the availability of a materials Clearance MARSSIM-based methodology developed and licensed in Spain. A typical project includes the integration of segregation, decontamination, clearance, quality control and quality assurance activities. The design is based in the clearance methodology features translating them into standard operational procedures. In terms of ecological taxes and final disposal costs, significant amounts of money could be saved with this type of approaches. The last clearance project managed a total amount of 405 tons scrap metal and a similar amount of other residual materials occupying a volume of 1500 m{sup 3}. After less than a year of field works 251 tons were finally recycled in a non-licensed smelting facility. The balance was disposed as LILW. In the planning phase the estimated cost savings were 4.5 Meuro. However, today a VLLW option is available in European countries so, the estimated cost savings are reduced to 1.2 Meuro. In conclusion: the application of materials clearance in NPP decommissioning lessons learnt to the NPP residual material management is an interesting management option. This practice is currently going on in Spanish NPP and, in a preliminary view, is consistent with the new MARSAME Draft. An interesting parameter is the cost of 1 m3 of recyclable scrap. The above estimates are very project specific because in the segregation process other residual materials were involved. If the effect of this other materials is removed the estimated Unit Cost were in this project around 1700 euro/m{sup 3}, this figure is clearly below the above VLLW disposal cost of 2600 euro. In a future project it appears feasible to descend to 839 euro/m{sup 3} and if it became routine values and is used in big Decommissioning projects, around 600 euro/m{sup 3} or below possibly could

  14. 21-PWR WASTE PACKAGE WITH ABSORBER PLATES LOADING CURVE EVALUATION

    SciTech Connect

    J.M. Scaglione

    2004-12-17

    The objective of this calculation is to evaluate the required minimum burnup as a function of initial pressurized water reactor (PWR) assembly enrichment that would permit loading of spent nuclear fuel into the 21 PWR waste package with absorber plates design as provided in Attachment IV. This calculation is an example of the application of the methodology presented in the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003). The scope of this calculation covers a range of enrichments from 0 through 5.0 weight percent U-235, and a burnup range of 0 through 45 GWd/MTU. Higher burnups were not necessary because 45 GWd/MTU was high enough for the loading curve determination. This activity supports the validation of the use of burnup credit for commercial spent nuclear fuel applications. The intended use of these results will be in establishing PWR waste package configuration loading specifications. Limitations of this evaluation are as follows: (1) The results are based on burnup credit for actinides and selected fission products as proposed in YMP (2003, Table 3-1) and referred to as the ''Principal Isotopes''. Any change to the isotope listing will have a direct impact on the results of this report. (2) The results are based on 1.5 wt% Gd in the Ni-Gd Alloy material and having no tuff inside the waste package. If the Gd loading is reduced or a process to introduce tuff inside the waste package is defined, then this report would need to be reevaluated based on the alternative materials. This calculation is subject to the ''Quality Assurance Requirements and Description'' (QARD) (DOE 2004) because it concerns engineered barriers that are included in the ''Q-List'' (BSC 2004k, Appendix A) as items important to safety and waste isolation.

  15. Comparing global models of terrestrial net primary productivity (NPP): Global pattern and differentiation by major biomes

    USGS Publications Warehouse

    Kicklighter, D.W.; Bondeau, A.; Schloss, A.L.; Kaduk, J.; McGuire, A.D.

    1999-01-01

    Annual and seasonal net primary productivity estimates (NPP) of 15 global models across latitudinal zones and biomes are compared. The models simulated NPP for contemporary climate using common, spatially explicit data sets for climate, soil texture, and normalized difference vegetation index (NDVI). Differences among NPP estimates varied over space and time. The largest differences occur during the summer months in boreal forests (50??to 60??N) and during the dry seasons of tropical evergreen forests. Differences in NPP estimates are related to model assumptions about vegetation structure, model parameterizations, and input data sets.

  16. Estimating probable flaw distributions in PWR steam generator tubes

    SciTech Connect

    Gorman, J.A.; Turner, A.P.L.

    1997-02-01

    This paper describes methods for estimating the number and size distributions of flaws of various types in PWR steam generator tubes. These estimates are needed when calculating the probable primary to secondary leakage through steam generator tubes under postulated accidents such as severe core accidents and steam line breaks. The paper describes methods for two types of predictions: (1) the numbers of tubes with detectable flaws of various types as a function of time, and (2) the distributions in size of these flaws. Results are provided for hypothetical severely affected, moderately affected and lightly affected units. Discussion is provided regarding uncertainties and assumptions in the data and analyses.

  17. RIA Limits Based On Commercial PWR Core Response To RIA

    SciTech Connect

    Beard, Charles L.; Mitchell, David B.; Slagle, William H.

    2006-07-01

    Reactivity insertion accident (RIA) limits have been under intense review by regulators since 1993 with respect to what should be the proper limit as a function of burnup. Some national regulators have imposed new lower limits while in the United States the limits are still under review. The data being evaluated with respect to RIA limits come from specialized test reactors. However, the use of test reactor data needs to be balanced against the response of a commercial PWR core in setting reasonable limits to insure the health and safety of the public without unnecessary restrictions on core design and operation. The energy deposition limits for a RIA were set in the 1970's based on testing in CDC (SPERT), TREAT, PBF and NSRR test reactors. The US limits given in radially averaged enthalpy are 170 cal/gm for fuel cladding failure and 280 cal/gm for coolability. Testing conducted in the 1990's in the CABRI, NSRR and IGR test reactors have demonstrated that the cladding failure threshold is reduced with burnup, with the primary impact due to hydrogen pickup for in-reactor corrosion. Based on a review of this data very low enthalpy limits have been proposed. In reviewing proposed limits from RIL-0401(1) it was observed that much of the data used to anchor the low allowable energy deposition levels was from recent NSRR tests which do not represent commercial PWR reactor conditions. The particular characteristics of the NSRR test compared to commercial PWR reactor characteristics are: - Short pulse width: 4.5 ms vs > 8 ms; - Low temperature conditions: < 100 deg. F vs 532 deg. F. - Low pressure environment: atmospheric vs {approx} 2200 psi. A review of the historical RIA database indicates that some of the key NSRR data used to support the RIL was atypical compared to the overall RIA database. Based on this detailed review of the RIA database and the response of commercial PWR core, the following view points are proposed. - The Failure limit should reflect local fuel

  18. PWR systems transient analysis: a reactor-safety perspective

    SciTech Connect

    Kennedy, M.F.; Abramson, P.B.; McDonald, T.A.

    1982-01-01

    In the simulation of transient events in large PWR reactor systems for reactor safety studies, the plant model is quite detailed and must include most of the plant components and control systems to adequately analyze the range of transients. The results discussed were calculated with the RELAP4/MOD6 code and reveal the need for the analysis to carefully review and understand the results to assure that they are not being adversely affected by the improper solution techniques or changes in models during the calculation.

  19. Electropolishing process development for PWR steam generator channel heads

    SciTech Connect

    Asay, R.H.; Graves, P.; Guastaferro, C.T.; Spalaris, C.N. )

    1991-04-01

    A broad range of process parameters was established to smoothen the surface of 309 L weld clad overlay, prototypic of surfaces common is channel heads of replacement PWR (pressurized water reactor) steam generators. Mechanical and electropolishing steps were studied to explore process boundaries, which result in acceptable degree of surface smoothness, without compromising metallurgical properties. Recommended processes and acceptance criteria established in this work, can be applied to electropolish steam generator channel heads. Smooth surfaces are less likely to retain radioactive species, and potentially develop lower radiation fields when these components are placed into service. 7 refs., 11 figs., 12 tabs.

  20. Key Features of the Deployed NPP/NPOESS Ground System

    NASA Astrophysics Data System (ADS)

    Heckmann, G.; Grant, K. D.; Mulligan, J. E.

    2010-12-01

    The National Oceanic & Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics & Space Administration (NASA) are jointly acquiring the next-generation weather/environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current NOAA Polar-orbiting Operational Environmental Satellites (POES) and DoD Defense Meteorological Satellite Program (DMSP). NPOESS satellites carry sensors to collect meteorological, oceanographic, climatological, and solar-geophysical data of the earth, atmosphere, and space. The ground data processing segment is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence & Information Systems (IIS). The IDPS processes NPOESS Preparatory Project (NPP)/NPOESS satellite data to provide environmental data products/records (EDRs) to NOAA and DoD processing centers operated by the US government. The IDPS will process EDRs beginning with NPP and continuing through the lifetime of the NPOESS system. The command & telemetry segment is the Command, Control & Communications Segment (C3S), also developed by Raytheon IIS. C3S is responsible for managing the overall NPP/NPOESS missions from control & status of the space and ground assets to ensuring delivery of timely, high quality data from the Space Segment to IDPS for processing. In addition, the C3S provides the globally-distributed ground assets needed to collect and transport mission, telemetry, and command data between the satellites and processing locations. The C3S provides all functions required for day-to-day satellite commanding & state-of-health monitoring, and delivery of Stored Mission Data to each Central IDP for data products development and transfer to system subscribers. The C3S also monitors and reports system-wide health & status and data communications with external systems and between the segments. The C3S & IDPS segments were delivered & transitioned to

  1. Gamma and Neutron Radiolysis in the 21-PWR Waste Package

    SciTech Connect

    J.S. Tang

    2001-05-03

    The objective of this calculation is to compute gamma and neutron dose rates in order to determine the maximum radiolytic production of nitric acid and other chemical species inside the 21-PWR (pressurized-water reactor) waste package (WP). The scope of this calculation is limited to the time period between 5,000 and 100,000 years after emplacement. The information provided by the sketches attached to this calculation is that of the potential design for the type of WP considered in this calculation. The results of this calculation will be used to evaluate nitric acid corrosion of fuel cladding from radiolysis in the 21-PWR WP. This calculation was performed in accordance with the Technical Work Plan for: Waste Package Design Description for LA (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M&O) 2000a). AP-3.124, Calculations, is used to perform the calculation and develop the document. This calculation is associated with the total system performance assessment (TSPA) of which the spent fuel cladding integrity is to be evaluated.

  2. Beta and gamma dose calculations for PWR and BWR containments

    SciTech Connect

    King, D.B.

    1989-07-01

    Analyses of gamma and beta dose in selected regions in PWR and BWR containment buildings have been performed for a range of fission product releases from selected severe accidents. The objective of this study was to determine the radiation dose that safety-related equipment could experience during the selected severe accident sequences. The resulting dose calculations demonstrate the extent to which design basis accident qualified equipment could also be qualified for the severe accident environments. Surry was chosen as the representative PWR plant while Peach Bottom was selected to represent BWRs. Battelle Columbus Laboratory performed the source term release analyses. The AB epsilon scenario (an intermediate to large LOCA with failure to recover onsite or offsite electrical power) was selected as the base case Surry accident, and the AE scenario (a large break LOCA with one initiating event and a combination of failures in two emergency cooling systems) was selected as the base case Peach Bottom accident. Radionuclide release was bounded for both scenarios by including spray operation and arrested sequences as variations of the base scenarios. Sandia National Laboratories used the source terms to calculate dose to selected containment regions. Scenarios with sprays operational resulted in a total dose comparable to that (2.20 /times/ 10/sup 8/ rads) used in current equipment qualification testing. The base case scenarios resulted in some calculated doses roughly an order of magnitude above the current 2.20 /times/ 10/sup 8/ rad equipment qualification test region. 8 refs., 23 figs., 12 tabs.

  3. VERA Core Simulator Methodology for PWR Cycle Depletion

    SciTech Connect

    Kochunas, Brendan; Collins, Benjamin S; Jabaay, Daniel; Kim, Kang Seog; Graham, Aaron; Stimpson, Shane; Wieselquist, William A; Clarno, Kevin T; Palmtag, Scott; Downar, Thomas; Gehin, Jess C

    2015-01-01

    This paper describes the methodology developed and implemented in MPACT for performing high-fidelity pressurized water reactor (PWR) multi-cycle core physics calculations. MPACT is being developed primarily for application within the Consortium for the Advanced Simulation of Light Water Reactors (CASL) as one of the main components of the VERA Core Simulator, the others being COBRA-TF and ORIGEN. The methods summarized in this paper include a methodology for performing resonance self-shielding and computing macroscopic cross sections, 2-D/1-D transport, nuclide depletion, thermal-hydraulic feedback, and other supporting methods. These methods represent a minimal set needed to simulate high-fidelity models of a realistic nuclear reactor. Results demonstrating this are presented from the simulation of a realistic model of the first cycle of Watts Bar Unit 1. The simulation, which approximates the cycle operation, is observed to be within 50 ppm boron (ppmB) reactivity for all simulated points in the cycle and approximately 15 ppmB for a consistent statepoint. The verification and validation of the PWR cycle depletion capability in MPACT is the focus of two companion papers.

  4. Suomi NPP VIIRS spectral characterization: understanding multiple RSR releases

    NASA Astrophysics Data System (ADS)

    Moeller, Chris; McIntire, Jeff; Schwarting, Tom; Moyer, Dave; Costa, Juliette

    2012-09-01

    The Suomi National Polar-orbiting Partnership (S-NPP) satellite was successfully launched on October 28, 2011, beginning the on-orbit era of the Visible Infrared Imager Radiometer Suite (VIIRS). In support of atlaunch readiness, VIIRS underwent a rigorous pre-launch test program to characterize its spatial, radiometric, and spectral performance. Spectral measurements, the subject of this paper, were collected during instrument level testing at Raytheon Corp. (summer 2009), and then again in a special spectral test for VisNIR bands during spacecraft level testing at Ball Aerospace and Technologies Corp. (spring 2010). These spectral performance measurements were analyzed by industry (Northrop Grumman, NG) and by the Relative Spectral Response (RSR) subgroup of the Government team, (NASA, Aerospace Corp., MIT/Lincoln Lab, Univ. Wisconsin) leading to releases of the S-NPP VIIRS RSR characterization by both NG and the Government team. The NG RSR analysis was planned to populate the Look-Up-Tables (LUTs) that support the various VIIRS operational products, while the Government team analysis was initially intended as a verification of the NG RSR product as well as an early release RSR characterization for the science community's pre-launch application. While the Government team deemed the NG December 2010 RSR release as acceptable for the "at-launch" RSR characterization during the pre-launch phase, the Government team has now (post-launch checkout phase) recommended for using the NG October 2011 RSR release as an update for the LUTs used in VIIRS SDR and EDR operational processing. Meanwhile the Government team RSR releases remain available to the community for their investigative interests, and may evolve if new understanding of VIIRS spectral performance is revealed in the S-NPP post-launch era.

  5. NPP/NPOESS Tools for Rapid Algorithm Updates

    NASA Astrophysics Data System (ADS)

    Route, G.; Grant, K. D.; Hughes, R.

    2010-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS Preparatory Project (NPP) and NPOESS satellites will carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes both NPP and NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government. The Northrop Grumman Aerospace Systems (NGAS) Algorithms and Data Products (A&DP) organization is responsible for the algorithms that produce the Environmental Data Records (EDRs), including their quality aspects. As the Calibration and Validation (Cal/Val) activities move forward following both the NPP launch and subsequent NPOESS launches, rapid algorithm updates may be required. Raytheon and Northrop Grumman have developed tools and processes to enable changes to be evaluated, tested, and moved into the operational baseline in a rapid and efficient manner. This presentation will provide an overview of the tools available to the Cal/Val teams to ensure rapid and accurate assessment of algorithm changes, along with the processes in place to ensure baseline integrity.

  6. Status of steam generator tubing integrity at Jaslovske Bohunice NPP

    SciTech Connect

    Cepcek, S.

    1997-02-01

    Steam generator represents one of the most important component of nuclear power plants. Especially, loss of tubing integrity of steam generators can lead to the primary coolant leak to secondary circuit and in worse cases to the unit shut down or to the PTS events occurrence. Therefore, to ensure the steam generator tubing integrity and the current knowledge about tube degradation propagation and development is of the highest importance. In this paper the present status of steam generator tubing integrity in operated NPP in Slovak Republic is presented.

  7. NPP4 is a procoagulant enzyme on the surface of vascular endothelium

    PubMed Central

    Albright, Ronald A.; Chang, William C.; Robert, Donna; Ornstein, Deborah L.; Cao, Wenxiang; Liu, Lynn; Redick, Meredith E.; Young, J. Isaac; De La Cruz, Enrique M.

    2012-01-01

    Ap3A is a platelet-dense granule component released into the extracellular space during the second wave of platelet aggregation on activation. Here, we identify an uncharacterized enzyme, nucleotide pyrophosphatase/phosphodiesterase-4 (NPP4), as a potent hydrolase of Ap3A capable of stimulating platelet aggregation and secretion. We demonstrate that NPP4 is present on the surface of vascular endothelium, where it hydrolyzes Ap3A into AMP and ADP, and Ap4A into AMP and ATP. Platelet aggregation assays with citrated platelet-rich plasma reveal that the primary and secondary waves of aggregation and dense granule release are strongly induced by nanomolar NPP4 in a concentration-dependent manner in the presence of Ap3A, while Ap3A alone initiates a primary wave of aggregation followed by rapid disaggregation. NPP2 and an active site NPP4 mutant, neither of which appreciably hydrolyzes Ap3A, have no effect on platelet aggregation and secretion. Finally, by using ADP receptor blockade we confirm that NPP4 mediates platelet aggregation via release of ADP from Ap3A and activation of ADP receptors. Collectively, these studies define the biologic and enzymatic basis for NPP4 and Ap3A activity in platelet aggregation in vitro and suggest that NPP4 promotes hemostasis in vivo by augmenting ADP-mediated platelet aggregation at the site of vascular injury. PMID:22995898

  8. A Study on Structured Simulation Framework for Design and Evaluation of Human-Machine Interface System -Application for On-line Risk Monitoring for PWR Nuclear Power Plant-

    SciTech Connect

    Zhan, J.; Yang, M.; Li, S.C.; Peng, M.J.; Yan, S.Y.; Zhang, Z.J.

    2006-07-01

    The operators in the main control room of Nuclear Power Plant (NPP) need to monitor plant condition through operation panels and understand the system problems by their experiences and skills. It is a very hard work because even a single fault will cause a large number of plant parameters abnormal and operators are required to perform trouble-shooting actions in a short time interval. It will bring potential risks if operators misunderstand the system problems or make a commission error to manipulate an irrelevant switch with their current operation. This study aims at developing an on-line risk monitoring technique based on Multilevel Flow Models (MFM) for monitoring and predicting potential risks in current plant condition by calculating plant reliability. The proposed technique can be also used for navigating operators by estimating the influence of their operations on plant condition before they take an action that will be necessary in plant operation, and therefore, can reduce human errors. This paper describes the risk monitoring technique and illustrates its application by a Steam Generator Tube Rupture (SGTR) accident in a 2-loop Pressurized Water Reactor (PWR) Marine Nuclear Power Plant (MNPP). (authors)

  9. TRANSPORT CHARACTERISTICS OF SELECTED PWR LOCA GENERATED DEBRIS.

    SciTech Connect

    A. K. MAJI; B. MARSHALL; ET AL

    2000-10-01

    In the unlikely event of a Loss of Coolant Accident (LOCA) in a pressurized water reactor (PWR), break jet impingement would dislodge thermal insulation from nearby piping, as well as other materials within the containment, such as paint chips, concrete dust, and fire barrier materials. Steam/water flows induced by the break and by the containment sprays would transport debris to the containment floor. Subsequently, debris would likely transport to and accumulate on the suction sump screens of the emergency core cooling system (ECCS) pumps, thereby potentially degrading ECCS performance and possibly even failing the ECCS. In 1998, the U. S. Nuclear Regulatory Commission (NRC) initiated a generic study (Generic Safety Issue-191) to evaluate the potential for the accumulation of LOCA related debris on the PWR sump screen and the consequent loss of ECCS pump net positive suction head (NPSH). Los Alamos National Laboratory (LANL), supporting the resolution of GSI-191, was tasked with developing a method for estimating debris transport in PWR containments to estimate the quantity of debris that would accumulate on the sump screen for use in plant specific evaluations. The analytical method proposed by LANL, to predict debris transport within the water that would accumulate on the containment floor, is to use computational fluid dynamics (CFD) combined with experimental debris transport data to predict debris transport and accumulation on the screen. CFD simulations of actual plant containment designs would provide flow data for a postulated accident in that plant, e.g., three-dimensional patterns of flow velocities and flow turbulence. Small-scale experiments would determine parameters defining the debris transport characteristics for each type of debris. The containment floor transport methodology will merge debris transport characteristics with CFD results to provide a reasonable and conservative estimate of debris transport within the containment floor pool and

  10. Multilevel modeling of NPP change and impacts of water resources in the Lower Heihe River Basin

    NASA Astrophysics Data System (ADS)

    Yan, Haiming; Zhan, Jinyan; Jiang, Qun'ou; Yuan, Yongwei; Li, Zhihui

    Net primary productivity (NPP) lays the foundation for provision of various ecosystem services, and understanding the impacts of potential influencing factors on NPP is of great significance to formulating appropriate management measures to guarantee the sustainable provision of essential ecosystem services. This study analyzed the impacts of potential influencing factors on NPP in the lower Heihe River Basin, a typical arid and semi-arid region in China. First, NPP was estimated with the C-FIX model, and then the multilevel model was used to analyze the impacts of potential influencing factors on NPP during 2000-2008. Finally decomposition analysis was used to further analyze the contribution of influencing factors to NPP change during 2000-2008. The average NPP increased by approximately 9.07% during 2000-2008, and results of the multilevel model indicate that both the socioeconomic variables and demographic variables are useful in explaining NPP change. In particular, coefficients of rainfall and evapotranspiration which represent the water availability reached 0.0456 and 0.2956, respectively. Results of decomposition analysis suggested that the water availability played an important role in increasing NPP, with a contribution rate of 44.17%, and it is necessary to carry out some policies that can promote the water use efficiency to increase NPP under the background of climate change and intensified human activities. There are some uncertainties in the results of this study, but these results still can provide valuable reference information for the water resource management to increase the ecosystem service supply in the lower Heihe River Basin.

  11. Possible satellite oceanography on coastal waters during the NPP stage

    NASA Astrophysics Data System (ADS)

    Zhu, J.; Asanuma, I.; Zhao, C.; Huang, B.

    2007-09-01

    Ocean color monitoring on the coastal water is still under study because of an incomplete atmospheric correction over the turbid water like over the coastal water along the China main land. Currently available sensors for science as MODIS on Terra or Aqua will terminate their service in the near future and the NPOESS Preparatory Project (NPP) will be the next satellite to support the satellite oceanography on the coastal water. The Tokyo University of Information Sciences (TUIS) has updated the MODIS receiving system to capture and ingest the Visible/Infrared Imager/Radiometer Suite (VIIRS) data from NPP, which will be launched in 2008. Data processing software from the Direct Readout Laboratory (DRL), such as the Real-time Software Telemetry Processing (RT-STPS), Simulcast, and DB algorithms, will be core programs in our system. VIIRS has seven bands in VIS&NIR, which are for ocean color research. The spatial resolution is 0.742×0.259 meters at nadir. While the MODIS spatial resolution of the nine ocean color bands is 1000m. The higher spatial resolution MODIS data (250 meters) is used to illustrate the advantage of the higher spatial resolution remote sensing data, such as data from VIIRS. In this study, we propose to combine the higher spatial resolution data with the traditional products of chlorophyll-a and sea surface temperature in the low resolution so as to extract further information on the coastal ocean.

  12. Comparison of S-NPP VIIRS and PLEIADES lunar observations

    NASA Astrophysics Data System (ADS)

    Xiong, Xiaoxiong; Lachérade, Sophie; Aznay, Ouahid; Fougnie, Bertrand; Fulbright, Jon; Wang, Zhipeng

    2015-10-01

    The first VIIRS instrument was launched on-board the S-NPP satellite in October 2011. It has a total of 15 reflective solar bands (RSB), which include a day-night band (DNB). The VIIRS RSB are calibrated each orbit by an on-board solar diffuser and regularly scheduled lunar observations. With a few exceptions, regularly scheduled lunar observations have been made with the same phase angles from -51.5° to -50.5°. The PLEIADES system consists of two satellites, PLEIADES-1A and PLEIADES-1B, which were launched in December of 2011 and December of 2012, respectively. Each instrument has 5 RSB: four (blue, green, red and near-infrared) bands with a 2.8 m spatial resolution and one panchromatic band with a 70 cm vertical viewing resolution. PLEIADES RSB are calibrated using observations of Pseudo Invariant Calibration Sites (PICS) and the Moon. Both PLEIADES-1A and PLEIADES-1B lunar observations have been made over a wide range of phase angles. In this paper we provide an overview of S-NPP VIIRS and PLEIADES lunar observations and an analysis to qualify their lunar calibration differences. Results derived from different inter-comparison methodologies (or approaches) are illustrated. Also discussed in this paper are the challenging issues, lessons, and future effort to further improve sensor lunar calibration inter-comparisons.

  13. Lessons Learned in Decommissioning of NPP A-1 After Accident

    SciTech Connect

    Prazska, M.; Rezbarik, J.; Majersky, D.; Sekely, S.; Solcanyi, S.

    2002-02-25

    Decommissioning of the NPP A-1 in Jaslovske Bohunice is encountered with great variation of the problems connected primarily with the high radiation fields and the high activity of the contaminated materials. Decontamination of the contaminated objects and the thorough radiological protection of decontamination workers are therefore the tasks of top priority. The successful realization of these jobs is based on the experience, good working practice and the utilization of all proven methods together with the newly developed ones. Since 1996, AllDeco Ltd. has applied the decontamination methods and processes in a wide scale in the decommissioning and dismantling of the NPP A-1 in the cooperation with SE-VYZ Inc. The monitoring of the radiation situation and the investigation of the type and character of the radioactive waste were first steps in the decontamination of all objects. For this works, remote controlled mechanical manipulators and remote controlled electrical carriage equipped with instruments recording the levels of dose rates and with telemetric data transmission system were used. The recorded data were used for the modeling and 3D visualization of the radiation fields and for following planning and preparation of the decontamination projects or ''working programs'' based on the ALARA principle. The minimization of the radioactive waste was also taken into consideration. A lot of time and energy was spent on the preparation and training of the staff including non-active trials of planned procedures. The gained experience was evaluated and lessons learned were given in the final reports.

  14. Modeling local chemistry in PWR steam generator crevices

    SciTech Connect

    Millett, P.J.

    1997-02-01

    Over the past two decades steam generator corrosion damage has been a major cost impact to PWR owners. Crevices and occluded regions create thermal-hydraulic conditions where aggressive impurities can become highly concentrated, promoting localized corrosion of the tubing and support structure materials. The type of corrosion varies depending on the local conditions, with stress corrosion cracking being the phenomenon of most current concern. A major goal of the EPRI research in this area has been to develop models of the concentration process and resulting crevice chemistry conditions. These models may then be used to predict crevice chemistry based on knowledge of bulk chemistry, thereby allowing the operator to control corrosion damage. Rigorous deterministic models have not yet been developed; however, empirical approaches have shown promise and are reflected in current versions of the industry-developed secondary water chemistry guidelines.

  15. Pump and valve fastener serviceability in PWR nuclear facilities

    SciTech Connect

    Moisidis, N.T.; Ratiu, M.D.

    1996-02-01

    The results of several studies conducted on corrosion of carbon and low-alloy steels in borated water have shown that impingement of borated steam on ferritic steels or contact with a moist paste of boric acid can lead to high corrosion rates due to high local concentrations of boric acid on the surface. The corrosion process of the flange fasteners of pumps and valves is considered a material compatibility and equipment maintenance problem. Therefore, the nuclear utilities of pressurized water reactor (PWR) power plants can prevent this damage by implementing appropriate fastener steel replacement and extended inspections to detect and correct the cause of leakage. A 3-phase corrosion protection program is presented for implementation based on system operability, outage-related accessibility, and cost of fastener replacement versus maintenance frequency increase. A selection criterion for fastener material is indicated based on service limitation: preloading and metal temperature.

  16. Ultrasonic Backscattering in Polycrystalline Materials of Pwr Components

    NASA Astrophysics Data System (ADS)

    Chassignole, B.; Dupond, O.; Fouquet, T.; Rupin, F.

    2011-06-01

    The ultrasonic examination of metallic components of Pressurized Water Reactors (PWR) is an important challenge for the nuclear industry. During the past decades, EDF R&D has undertaken numerous studies in order to improve the NDT process on these applications and to help to their qualification. The present paper deals with the problem of the structural noise which can potentially disturbs the ultrasonic inspection. In particular, this study proposes a modeling approach to simulate the ultrasonic scattering due to coarse grain structures of polycrystalline materials. The methodology is based on the mixing of a grain scale description of the material and a 2D finite element code (ATHENA) developed by EDF to simulate the ultrasonic propagation in isotropic and anisotropic elastic media. The modeling results are compared to experimental acquisitions on mock-ups containing artificial defects.

  17. Fracture mechanics evaluation for at typical PWR primary coolant pipe

    SciTech Connect

    Tanaka, T.; Shimizu, S.; Ogata, Y.

    1997-04-01

    For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan by means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.

  18. 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

  19. A comparison of fuzzy logic-PID control strategies for PWR pressurizer control

    SciTech Connect

    Kavaklioglu, K.; Ikonomopoulos, A. )

    1993-01-01

    This paper describes the results obtained from a comparison performed between classical proportional-integral-derivative (PID) and fuzzy logic (FL) controlling the pressure in a pressurized water reactor (PWR). The two methodologies have been tested under various transient scenarios, and their performances are evaluated with respect to robustness and on-time response to external stimuli. One of the main concerns in the safe operation of PWR is the pressure control in the primary side of the system. In order to maintain the pressure in a PWR at the desired level, the pressurizer component equipped with sprayers, heaters, and safety relief valves is used. The control strategy in a Westinghouse PWR is implemented with a PID controller that initiates either the electric heaters or the sprayers, depending on the direction of the coolant pressure deviation from the setpoint.

  20. Evaluation of thermal mixing data from a model cold leg and downcomer. [PWR

    SciTech Connect

    Rothe, P.H.; Fanning, M.W.

    1982-12-01

    This report describes an evaluation of thermal mixing data obtained in a 1/5-scale, transparent model of the cold leg and downcomer of a Pressurized Water Reactor (PWR). The data are relevant to the phenomenon of fluid and thermal mixing following HPI (High Pressure Injection) of coolant water in a PWR loop. The data are reduced, correlated and compared with theoretically derived values and scaling approaches.

  1. Identification and evaluation of PWR in-vessel severe accident management strategies

    SciTech Connect

    Dukelow, J S; Harrison, D G; Morgenstern, M

    1992-03-01

    This reports documents work performed the NRC/RES Accident Management Guidance Program to evaluate possible strategies for mitigating the consequences of PWR severe accidents. The selection and evaluation of strategies was limited to the in-vessel phase of the severe accident, i.e., after the initiation of core degradation and prior to RPV failure. A parallel project at BNL has been considering strategies applicable to the ex-vessel phase of PWR severe accidents.

  2. Characterization of Decommissioned PWR Vessel Internals Materials Samples: Material Certification, Fluence, and Temperature (Nonproprietary Version)

    SciTech Connect

    M. Krug; R. Shogan; A. Fero; M. Snyder

    2004-11-01

    Pressurized water reactor (PWR) cores, operate under extreme environmental conditions due to coolant chemistry, operating temperature, and neutron exposure. Extending the life of PWRs require detailed knowledge of the changes in mechanical and corrosion properties of the structural austenitic stainless steel components adjacent to the fuel. This report contains basic material characterization information of the as-installed samples of reactor internals material which were harvested from a decommissioned PWR.

  3. Characterization of Decommissioned PWR Vessel Internals Material Samples: Tensile and SSRT Testing (Nonproprietary Version)

    SciTech Connect

    M.Krug, R.Shogan

    2004-09-01

    Pressurized water reactor (PWR) cores operate under extreme environmental conditions due to coolant chemistry, operating temperature, and neutron exposure. Extending the life of PWRs requires detailed knowledge of the changes in mechanical and corrosion properties of the structural austenitic stainless steel components adjacent to the fuel (internals) subjected to such conditions. This project studied the effects of reactor service on the mechanical and corrosion properties of samples of baffle plate, former plate, and core barrel from a decommissioned PWR.

  4. Degradation and Failure Characteristics of NPP Containment Protective Coating Systems

    SciTech Connect

    Sindelar, R.L.

    2001-04-10

    Nuclear power plants (NPPs) must ensure that the emergency core cooling system (ECCS) or safety-related containment spray system (CSS) remains capable of performing its design safety function throughout the life of the plant. This requires ensuring that long-term core cooling can be maintained following a postulated loss-of-coolant accident (LOCA). Adequate safety operation can be impaired if the protective coatings which have been applied to the concrete and steel structures within the primary containment fail, producing transportable debris which could then accumulate on BWR ECCS suction strainers or PWR ECCS sump debris screens located within the containment. This document will present the data collected during the investigation of coating specimens from plants.

  5. Small Break LOCA Analysis of ACR-700 NPP

    SciTech Connect

    Limin Zheng; Sen Shen; Wright, David

    2006-07-01

    A small break loss of coolant accident (SB-LOCA) analysis to assess a preliminary conceptual design of the ACR-700 PHWR nuclear power plant (NPP) developed by AECL has been performed with CATHENA MOD 3.5d, a PHWR system thermal-hydraulic analysis code. The limiting break size has been found by performing a sensitivity study for three different break locations [i.e. reactor inlet header (RIH), HTS pump suction (PS) pipe and reactor outlet head (ROH)] under the limiting case (i.e. SB-LOCA with subsequent loss of class IV power with all safety systems available). The analysis results indicate that the SB-LOCA acceptance criteria are satisfied. (authors)

  6. Near Real Time Processing Chain for Suomi NPP Satellite Data

    NASA Astrophysics Data System (ADS)

    Monsorno, Roberto; Cuozzo, Giovanni; Costa, Armin; Mateescu, Gabriel; Ventura, Bartolomeo; Zebisch, Marc

    2014-05-01

    Since 2009, the EURAC satellite receiving station, located at Corno del Renon, in a free obstacle site at 2260 m a.s.l., has been acquiring data from Aqua and Terra NASA satellites equipped with Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. The experience gained with this local ground segmenthas given the opportunity of adapting and modifying the processing chain for MODIS data to the Suomi NPP, the natural successor to Terra and Aqua satellites. The processing chain, initially implemented by mean of a proprietary system supplied by Seaspace and Advanced Computer System, was further developed by EURAC's Institute for Applied Remote Sensing engineers. Several algorithms have been developed using MODIS and Visible Infrared Imaging Radiometer Suite (VIIRS) data to produce Snow Cover, Particulate Matter estimation and Meteo maps. These products are implemented on a common processor structure based on the use of configuration files and a generic processor. Data and products have then automatically delivered to the customers such as the Autonomous Province of Bolzano-Civil Protection office. For the processing phase we defined two goals: i) the adaptation and implementation of the products already available for MODIS (and possibly new ones) to VIIRS, that is one of the sensors onboard Suomi NPP; ii) the use of an open source processing chain in order to process NPP data in Near Real Time, exploiting the knowledge we acquired on parallel computing. In order to achieve the second goal, the S-NPP data received and ingested are sent as input to RT-STPS (Real-time Software Telemetry Processing System) software developed by the NASA Direct Readout Laboratory 1 (DRL) that gives as output RDR files (Raw Data Record) for VIIRS, ATMS (Advanced Technology Micorwave Sounder) and CrIS (Cross-track Infrared Sounder)sensors. RDR are then transferred to a server equipped with CSPP2 (Community Satellite Processing Package) software developed by the University of

  7. Degradation and Failure Characteristics of NPP Containment Protective Coating Systems

    SciTech Connect

    Sindelar, R.L.

    2001-02-22

    A research program to investigate the performance and potential for debris formation of Service Level I coating systems used in nuclear power plant containment is being performed at the Savannah River Technology Center. The research activities are aligned to address phenomena important to cause coating disbondment as identified by the Industry Coatings Expert Panel. The period of interest for performance covers the time from application of the coating through 40 years of service, followed by a medium-to-large break loss-of-coolant accident scenario, which is a design basis accident (DBA) scenario. The interactive program elements are described in this report and the application of these elements to evaluate the performance of the specific coating system of Phenoline 305 epoxy-phenolic topcoat over Carbozinc 11 primer on a steel substrate. This system is one of the predominant coating systems present on steel substrates in NPP containment.

  8. NPP VIIRS Early On-Orbit Geometric Performance

    NASA Technical Reports Server (NTRS)

    Wolfe, Robert E.; Lin, Guoqing; Nishihama, Masahiro; Tewari, Krishna; Montano, Enrique

    2012-01-01

    The NASA/NOAA Visible Infrared Imager Radiometer Suite (VIIRS) instrument on-board the Suomi National Polar-orbiting Partnership (NPP) satellite was launched in October, 2011. The instrument geometric performance includes sensor spatial response, band-to-band co-registration (BBR), and geolocation accuracy and precision. The geometric performance is an important aspect of sensor data record (SDR) calibration and validation. In this paper we will discuss geometric performance parameter characterization using the first seven-month of VIIRS' earth and lunar data, and compare with the at-launch performance using ground testing data and analysis of numerical modeling results as the first step in on-orbit geometric calibration and validation.

  9. Scoping Study Investigating PWR Instrumentation during a Severe Accident Scenario

    SciTech Connect

    Rempe, J. L.; Knudson, D. L.; Lutz, R. J.

    2015-09-01

    The accidents at the Three Mile Island Unit 2 (TMI-2) and Fukushima Daiichi Units 1, 2, and 3 nuclear power plants demonstrate the critical importance of accurate, relevant, and timely information on the status of reactor systems during a severe accident. These events also highlight the critical importance of understanding and focusing on the key elements of system status information in an environment where operators may be overwhelmed with superfluous and sometimes conflicting data. While progress in these areas has been made since TMI-2, the events at Fukushima suggests that there may still be a potential need to ensure that critical plant information is available to plant operators. Recognizing the significant technical and economic challenges associated with plant modifications, it is important to focus on instrumentation that can address these information critical needs. As part of a program initiated by the Department of Energy, Office of Nuclear Energy (DOE-NE), a scoping effort was initiated to assess critical information needs identified for severe accident management and mitigation in commercial Light Water Reactors (LWRs), to quantify the environment instruments monitoring this data would have to survive, and to identify gaps where predicted environments exceed instrumentation qualification envelop (QE) limits. Results from the Pressurized Water Reactor (PWR) scoping evaluations are documented in this report. The PWR evaluations were limited in this scoping evaluation to quantifying the environmental conditions for an unmitigated Short-Term Station BlackOut (STSBO) sequence in one unit at the Surry nuclear power station. Results were obtained using the MELCOR models developed for the US Nuclear Regulatory Commission (NRC)-sponsored State of the Art Consequence Assessment (SOARCA) program project. Results from this scoping evaluation indicate that some instrumentation identified to provide critical information would be exposed to conditions that

  10. The kinetics of aerosol particle formation and removal in NPP severe accidents

    NASA Astrophysics Data System (ADS)

    Zatevakhin, Mikhail A.; Arefiev, Valentin K.; Semashko, Sergey E.; Dolganov, Rostislav A.

    2016-06-01

    Severe Nuclear Power Plant (NPP) accidents are accompanied by release of a massive amount of energy, radioactive products and hydrogen into the atmosphere of the NPP containment. A valid estimation of consequences of such accidents can only be carried out through the use of the integrated codes comprising a description of the basic processes which determine the consequences. A brief description of a coupled aerosol and thermal-hydraulic code to be used for the calculation of the aerosol kinetics within the NPP containment in case of a severe accident is given. The code comprises a KIN aerosol unit integrated into the KUPOL-M thermal-hydraulic code. Some features of aerosol behavior in severe NPP accidents are briefly described.

  11. Joint probability safety assessment for NPP defense infrastructure against extreme external natural hazards

    SciTech Connect

    Guilin, L.; Defu, L.; Huajun, L.; Fengqing, W.; Tao, Z.

    2012-07-01

    With the increasing tendency of natural hazards, the typhoon, hurricane and tropical Cyclone induced surge, wave, precipitation, flood and wind as extreme external loads menacing Nuclear Power Plants (NPP) in coastal and inland provinces of China. For all of planned, designed And constructed NPP the National Nuclear Safety Administration of China and IAEA recommended Probable Maximum Hurricane /Typhoon/(PMH/T), Probable Maximum Storm Surge (PMSS), Probable Maximum Flood (PMF), Design Basis Flood (DBF) as safety regulations for NPP defense infrastructures. This paper discusses the joint probability analysis of simultaneous occurrence typhoon induced extreme external hazards and compare with IAEA 2006-2009 recommended safety regulation design criteria for some NPP defense infrastructures along China coast. (authors)

  12. An Overview of NPP VIIRS Pre-Launch and On-Orbit Calibration and Characterization

    NASA Technical Reports Server (NTRS)

    Butler, Jim; Gleason, Jim; Xiong, Jack; Chang, Vincent; Lee, Shih Yan

    2011-01-01

    NPP Visible Infrared Imaging Radiometer Suite (VIIRS) test program at the instrument and observatory level is complete and has provided an extensive amount of high quality data to enable the assessment of sensor performance.

  13. The dry season intensity as a key driver of NPP trends

    NASA Astrophysics Data System (ADS)

    Murray-Tortarolo, Guillermo; Friedlingstein, Pierre; Sitch, Stephen; Seneviratne, Sonia I.; Fletcher, Imogen; Mueller, Brigitte; Greve, Peter; Anav, Alessandro; Liu, Yi; Ahlström, Anders; Huntingford, Chris; Levis, Sam; Levy, Peter; Lomas, Mark; Poulter, Benjamin; Viovy, Nicholas; Zaehle, Sonke; Zeng, Ning

    2016-03-01

    We analyze the impacts of changing dry season length and intensity on vegetation productivity and biomass. Our results show a wetness asymmetry in dry ecosystems, with dry seasons becoming drier and wet seasons becoming wetter, likely caused by climate change. The increasingly intense dry seasons were consistently correlated with a decreasing trend in net primary productivity (NPP) and biomass from different products and could potentially mean a reduction of 10-13% in NPP by 2100. We found that annual NPP in dry ecosystems is particularly sensitive to the intensity of the dry season, whereas an increase in precipitation during the wet season has a smaller effect. We conclude that changes in water availability over the dry season affect vegetation throughout the whole year, driving changes in regional NPP. Moreover, these results suggest that usage of seasonal water fluxes is necessary to improve our understanding of the link between water availability and the land carbon cycle.

  14. Assessment of NPP VIIRS Ocean Color Data Products: Hope and Risk

    NASA Technical Reports Server (NTRS)

    Turpie, Kevin R.; Meister, Gerhard; Eplee, Gene; Barnes, Robert A.; Franz, Bryan; Patt, Frederick S.; Robinson, Wayne d.; McClain, Charles R.

    2010-01-01

    For several years, the NASA/Goddard Space Flight Center (GSFC) NPP VIIRS Ocean Science Team (VOST) provided substantial scientific input to the NPP project regarding the use of Visible Infrared Imaging Radiometer Suite (VIIRS) to create science quality ocean color data products. This work has culminated into an assessment of the NPP project and the VIIRS instrument's capability to produce science quality Ocean Color data products. The VOST concluded that many characteristics were similar to earlier instruments, including SeaWiFS or MODIS Aqua. Though instrument performance and calibration risks do exist, it was concluded that programmatic and algorithm issues dominate concerns. Keywords: NPP, VIIRS, Ocean Color, satellite remote sensing, climate data record.

  15. Consistency of CERES Radiances and Fluxes from Aqua and Suomi-NPP

    NASA Technical Reports Server (NTRS)

    Liang, Lusheng; Miller, Walter; Su, Wenying; Loeb, Norman

    2015-01-01

    The Clouds and Earth's Radiant Energy System (CERES) instruments on board Terra, Aqua, and Suomi-NPP have been providing data products critical to advancing our understanding of the effects of clouds and aerosols on radiative energy within the Earth-atmosphere system. The CERES instrument consists of a threechannel broadband scanning radiometer. The scanning radiometer measures radiances in shortwave (SW, 0.3-5 micron), window (WN, 8-12 micron), and total (0.3-200 micron) channels. The longwave (LW) component is derived as the difference between total and SW channels. These measured radiances at a given sun-Earthsatellite geometry are converted to outgoing reflected solar and emitted thermal TOA radiative fluxes by using CERES scene-type dependent angular distribution models (ADMs). The CERES instruments must remain radiometrically stable and correctly inter-calibrated to accurately capture changes in Earth"s radiation budget from interannual to decadal timescales. This presentation will focus on comparisons between collocated radiance measurements from CERES instruments on Aqua and on Suomi-NPP. As we do not have a set of ADMs that is constructed specifically for the CERES instrument on Suomi-NPP, CERES Aqua ADMs are used to invert fluxes from radiance measurements on Suomi-NPP. But the CERES Aqua footprint size is smaller than the CERES Suomi-NPP footprint size and the scene identifications provided by MODIS and VIIRS can also be different from each other. Will using Aqua ADMs for Suomi-NPP flux inversion increase the flux uncertainty? We will examine the deseasonalized flux anomaly time series using Aqua data alone and using combined Aqua and Suomi-NPP data. We will also present a simulation study to assess the Suomi-NPP flux uncertainty from using Aqua ADMs for the flux inversion.

  16. Experience in PWR and BWR mixed-oxide fuel management

    SciTech Connect

    Schlosser, G.J.; Krebs, W.; Urban, P. )

    1993-04-01

    Germany has adopted the strategy of a closed fuel cycle using reprocessing and recycling. The central issue today is plutonium recycling by the use of U-Pu mixed oxide (MOX) in pressurized water reactors (PWRs) and boiling water reactors (BWRs). The design of MOX fuel assemblies and fuel management in MOX-containing cores are strongly influenced by the nuclear properties of the plutonium isotopes. Optimized MOX fuel assembly designs for PWRs currently use up to three types of MOX fuel rods having different plutonium contents with natural uranium or uranium tailings as carrier material but without burnable absorbers. The MOX fuel assembly designs for BWRs use four to six rod types with different plutonium contents and Gd[sub 2]O[sub 3]/UO[sub 2] burnable absorber rods. Both the PWR and the BWR designs attain good burnup equivalence and compatibility with uranium fuel assemblies. High flexibility exists in the loading schemes relative to the position and number of MOX fuel assemblies in the reloads and in the core as a whole. The Siemens experience with MOX fuel assemblies is based on the insertion of 318 MOX fuel assemblies in eight PWRs and 168 in BWRs and pressurized heavy water reactors so far. The primary operating results include information on the cycle length, power distribution, reactivity coefficients, and control rod worth of cores containing MOX fuel assemblies.

  17. Containment integrity of SEP plants under combined loads. [PWR; BWR

    SciTech Connect

    Lo, T.; Nelson, T.A.; Chen, P.Y.; Persinko, D.; Grimes, C.

    1984-06-01

    Because the containment structure is the last barrier against the release of radioactivity, an assessment was undertaken to identify the design weaknesses and estimate the margins of safety for the SEP containments under the postulated, combined loading conditions of a safe shutdown earthquake (SSE) and a design basis accident (DBA). The design basis accident is either a loss-of-coolant accident (LOCA) or a main steam line break (MSLB). The containment designs analyzed consisted of three inverted light-bulb shaped drywells used in boiling water reactor (BWR) systems, and three steel-lined concrete containments and a spherical steel shell used in pressurized water reactor (PWR) systems. These designs cover a majority of the containment types used in domestic operating plants. The results indicate that five of the seven designs are adequate even under current design standards. For the remaining two designs, the possible design weaknesses identified were buckling of the spherical steel shell and over-stress in both the radial and tangential directions in one of the concrete containments near its base.

  18. Integrity of PWR pressure vessels during overcooling accidents

    SciTech Connect

    Cheverton, R.D.; Iskander, S.K.; Whitman, G.D.

    1982-01-01

    The reactor pressure vessel in a pressurized water reactor is normally subjected to temperatures and pressures that preclude propagation of sharp, crack-like defects that might exist in the wall of the vessel. However, there is a class of postulated accidents, referred to as overcooling accidents, that can subject the pressure vessel to severe thermal shock while the pressure is substantial. As a result of such accidents, vessels containing high concentrations of copper and nickel, which enhance radiation embrittlement, may possess a potential for extensive propagation of preexistent inner surface flaws prior to the vessel's normal end of life. A state-of-the-art fracture-mechanics model was developed and has been used for conducting parametric analyses and for calculating several recorded PWR transients. Results of the latter analysis indicate that there may be some vessels that have a potential for failure in a few years if subjected to a Rancho Seco-type transient. However, the calculational model may be excessively conservative, and this possibility is under investigation.

  19. Integrity of PWR pressure vessels during overcooling accidents

    SciTech Connect

    Cheverton, R.D.; Iskander, S.K.; Whitman, G.D.

    1982-01-01

    The reactor pressure vessel in a pressurized water reactor is normally subjected to temperatures and pressures that preclude propagation of sharp, crack-like defects that might exist in the wall of the vessel. However, there is a class of postulated accidents, referred to as overcooling accidents, that can subject the pressure vessel to severe thermal shock while the pressure is substantial. As a result of such accidents vessels containing high concentrations of copper and nickel, which enhance radiation embrittlement, may possess a potential for extensive propagation of preexistent inner surface flaws prior to the vessel's normal end of life. For the purpose of evaluating this problem a state-of-the-art fracture mechanics model was developed and has been used for conducting parametric analyses and for calculating several recorded PWR transients. Results of the latter analysis indicate that there may be some vessels that have a potential for failure today if subjected to a Rancho Seco (1978) or TMI-2 (1979) type transient. However, the calculational model may be excessively conservative, and this possibility is under investigation.

  20. Parameterization of Buoyancy Effects in Generic PWR Boron Dilution Scenarios

    SciTech Connect

    Galindo-Garcia, Ivan F.; Cotton, Mark A.; Axcell, Brian P.

    2006-07-01

    A computational investigation is undertaken into the role of buoyancy in a PWR boron dilution transient following a postulated Small Break Loss of Coolant Accident (SB-LOCA). In the scenario envisaged there is flow of de-borated and relatively high temperature water from a single cold leg into the downcomer; flow rates are typical of natural circulation conditions. The study focuses upon the development of boron concentration distributions in the downcomer and adopts a 3D-unsteady formulation of the mean flow equations in combination with the standard high-Reynolds-number k-{epsilon} turbulence model. It is found that the Richardson number (Ri = Gr/Re{sup 2}) is the most important group parameterizing the course of a concentration transient. At Ri values characterizing a 'baseline' scenario the results indicate that there is a stable, circumferentially-uniform, descent through the downcomer of a stratified region of low-borated fluid. Qualitatively the same behaviour is found at higher Richardson number, although at Ri values of approximately one-fifth the baseline level there is evidence of large-scale mixing and a consequent absence of concentration stratification. (authors)

  1. MODIS GPP/NPP for complex land use area: a case study of comparison between MODIS GPP/NPP and ground-based measurements over Korea

    NASA Astrophysics Data System (ADS)

    Shim, C.

    2013-12-01

    The Moderate Resolution Imaging Radiometer (MODIS) Gross Primary Productivity (GPP)/Net Primary Productivity (NPP) has been widely used for the study on global terrestrial ecosystem and carbon cycle. The current MODIS product with ~ 1 km spatial resolution, however, has limitation on the information on local scale environment (< 1km), particularly on the regions with complex land-use types. Here we try to test the performance of MODIS annual GPP/NPP for a case of Korea, where the vegetation types are mostly heterogeneous within a size of MODIS products (~1km). We selected the sites where the ground/tower flux measurements and MODIS retrievals were simultaneously available and the land classification of sites agreed the forest type map (~71m) (1 site over Gwangneung flux tower (GDK) for 2006-2008 and 2 sites of ground measurements over Cheongju (CJ1 and CJ2) for 2011). The MODIS GPP are comparable to that of GDK (largely deciduous forest) within -6.3 ~ +2.3% of bias (-104.5 - 37.9 gCm-2yr-1). While the MODIS NPP of CJ1 at Cheongju (largely Larix leptolepis) underestimated NPP by 34% (-224.5 gCm-2yr-1), the MODIS NPP of CJ2 (largely Pinus densiflora) agreed well with -0.2% of bias (1.6 gCm-2yr-1). The fairly comparable values of the MODIS here however, cannot assure the quality of the MOD17 over the complex vegetation area of Korea since the ground measurements except the eddy covariance tower flux measurements are highly inconsistent. Therefore, the comprehensive experiments to represents GPP/NPP over diverse vegetation types for a comparable scale of MODIS with a consistent measurement technique are necessary in order to evaluate the MODIS vegetation productivity data over Korea, which contains a large portion of highly heterogeneous vegetation area.

  2. Fruit development, not GPP, drives seasonal variation in NPP in a tropical palm plantation.

    PubMed

    Navarro, M N V; Jourdan, C; Sileye, T; Braconnier, S; Mialet-Serra, I; Saint-Andre, L; Dauzat, J; Nouvellon, Y; Epron, D; Bonnefond, J M; Berbigier, P; Rouziere, A; Bouillet, J P; Roupsard, O

    2008-11-01

    We monitored seasonal variations in net primary production (NPP), estimated by allometric equations from organ dimensions, gross primary production (GPP), estimated by the eddy covariance method, autotrophic respiration (R(a)), estimated by a model, and fruit production in a coconut (Cocos nucifera L.) plantation located in the sub-tropical South Pacific archipelago of Vanuatu. Net primary production of the vegetative compartments of the trees accumulated steadily throughout the year. Fruits accounted for 46% of tree NPP and showed large seasonal variations. On an annual basis, the sum of estimated NPP (16.1 Mg C ha(-1) year(-1)) and R(a) (24.0 Mg C ha(-1) year(-1)) for the ecosystem (coconut trees and herbaceous understory) closely matched GPP (39.0 Mg C ha(-1) year(-1)), suggesting adequate cross-validation of annual C budget methods. However, seasonal variations in NPP + R(a) were smaller than the seasonal variations in GPP, and maximum tree NPP occurred 6 months after the midsummer peak in GPP and solar radiation. We propose that this discrepancy reflects seasonal variation in the allocation of dry mass to carbon reserves and new plant tissue, thus affecting the allometric relationships used for estimating NPP. PMID:18765371

  3. A comparison of HLW-glass and PWR-borate waste glass

    NASA Astrophysics Data System (ADS)

    Luo, Shanggeng; Sheng, Jiawei; Tang, Baolong

    2001-09-01

    Glass can incorporate a wide variety of wastes ranging from high level wastes (HLW) to low and intermediate level wastes (LILW). A comparison of HLW-Glass and PWR-borate waste glass is given in this paper. The HLW glass formulation named GC-12/9B and 90-19/U can incorporate 16-20 wt% HLW at 1100°C or 1150°C. The borate waste glass named SL-1 can incorporate 45 wt% borate waste generated from PWR. Their physical properties, characteristic temperatures, chemical durability and leach behavior are summarized here. The comparison indicates: the PWR-glass SL-1 can incorporate up to 45 wt% waste oxides at lower melting temperature (1000°C) in agreement with minimum additive waste stabilization (MAWS) approach; owing to the PWR-borate glass contain less Si and more B and Na, its mass loss is higher than HWR-glass; both HLW-glass and PWR-borate glass have favorable chemical durability and the same leaching phenomena, i.e., Na is mostly depleted, but Ca, Mg, Al and Ti are enriched in the leached surface layer.

  4. Initial Assessment of NPP/VIIRS Aerosol Environmental Data

    NASA Astrophysics Data System (ADS)

    Laszlo, I.; Kondragunta, S.; Remer, L. A.

    2012-12-01

    The aerosol environment data records (EDR) derived from the measurements of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the recently launched Suomi National Polar-orbiting Partnership (NPP) satellite are the aerosol optical thickness (AOT), aerosol particle size parameter (APSP, characterized in terms of the Angstrom Exponent, AE), and suspended matter (SM). These EDRs go through various evaluations to assess their level of maturity, which are defined by a set of criteria. This presentation provides an overview of the work and results the NPP/JPSS Calibration/Validation Team has performed for the first of the maturity levels, Beta. For this level, the VIIRS AOT and APSP products have been compared with aerosol products derived from MODIS observations onboard the NASA Earth Observing System (EOS) satellite (Aqua), and with AERONET products and observations. SM has been compared with CALIPSO products. All comparisons have been applied to a uniform time sample (2 May 2012 to 2 June 2012). Qualitative and quantitative analysis of the VIIRS aerosol EDRs indicate that AOT both over land and ocean, and APSP over ocean have reached Beta maturity. However, neither APSP over land, nor SM qualifies for Beta level at this time. Qualitatively, one standard deviation of VIIRS AOT EDR products fall within ±0.09 ±10% of collocated MODIS retrievals over land and ±0.02 ±10% over ocean. The same VIIRS product falls within ±0.13 ±15% of collocated AERONET over land and ±0.04 ±5% over ocean. In all cases, the VIIRS AOT over land product is biased high (0.07 to 0.15) against comparable products in a global sense. The VIIRS Angstrom Exponent EDR product over ocean shows correlation when compared with MODIS, but is biased high. Preliminary AERONET analysis at coastal stations shows APSP falling within approximately ±0.40 of AERONET. Preliminary AERONET analysis at coastal stations shows APSP falling within approximately ±0.40 of AERONET. VIIRS Angstrom Exponent

  5. Operational Applications from the Suomi Npp and Jpss Satellites

    NASA Astrophysics Data System (ADS)

    Goldberg, M.; Furgerson, J.; Sjoberg, W.; Weng, F.; Csiszar, I. A.; Kilcoyne, H.; Gleason, J. F.

    2012-12-01

    The Joint Polar Satellite System is NOAA's new operational satellite program and includes the SUOMI National Polar Partnership (NPP) as a bridge between NOAA's operational Polar Orbiting Environmental Satellite (POES) series, which began in 1978, and the first JPSS operational satellite scheduled for launch in 2017. JPSS provides critical data for key NOAA product and services, which the Nation depends on. These products and services include: Weather forecasting - data from the JPSS Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) are needed to forecast weather events out to 7 days. Nearly 85% of all data used in weather forecasting are from polar orbiting satellites. Environmental monitoring - data from the JPSS Visible Infrared Imager Radiometer Suite (VIIRS) are used to monitor the environment including the health of coastal ecosystems, drought conditions, fire, smoke, dust, snow and ice, and the state of oceans, including sea surface temperature and ocean color. Climate monitoring - data from JPSS instruments, including OMPS, CERES and TSIS will provide continuity to climate data records established using NOAA POES and NASA Earth Observing System (EOS) satellite observations. These data records provide a unified and coherent long-term observation of the environment; the records and products are critical to climate modelers, scientists, and decision makers concerned with advancing climate change understanding, prediction, mitigation and adaptation strategies, and policies. Data collection - JPSS satellites continue the POES data collection instruments that relay in situ data and observations from remote transmitters. These instruments relay data from remote, unmanned stations including wind, temperature and salinity readings from ocean buoys, which allow for the monitoring of the ocean. These instruments are also used to track wildlife. Search and rescue - JPSS will continue the search and rescue instruments on POES that

  6. Modeling of temporal and spatial coherency of net primary production (MODIS NPP) in the mountain forests of South Siberia

    NASA Astrophysics Data System (ADS)

    Ivanova, Yulia; Soukhovolsky, Vlad

    Net primary production (NPP) of mountain forest is very variable and depends on a variety of external modifying factors such as intensity and spectrum of solar radiation, climatic conditions in the area. Less studied are features of long-term NPP dynamics associated with self-regulation processes of tree growth in a forest. Mountain forests are a convenient object for analysis and modeling of long-term NPP changes that do not depend on climatic factors, since in mountain forests climatic conditions are uniquely determined by altitude Temporal and spatial coherence of mean annual NPP time series (Yrs. 2000 - 2012) was studied according to data from satellite observations of MODIS/TERRA. Mean annual NPP estimates' series were examined for different altitudinal zones in the Sayan Mountains (South of Central Siberia). Altitudes ranged from 600 to 1.800 meters above sea level. This area is lengthful vertically and has well-marked mountain-belt vegetation complexes, where mixed forests, fir and pine coniferous forests, alpine meadows and alpine tundra successively come one after another. Spatial and temporal coherence of NPP time series for different habitats is analyzed. The analysis showed that variations in annual NPP values of the fir (Abies sibirica) at different altitudes (450-1700 m) are synchronized. These variations in NPP values are described by the AR(2) model. Such behavior of studied NPP time series suggests a lag in growth of woody plants. In this case, the current NPP is influenced by the NPP values of the two previous years. At higher altitudes, where the density of the trees decreases and herbaceous plants become dominant, the range and synchronization of NPP variations decrease.

  7. Materials Reliability Program: Fracture Toughness Testing of Decommissioned PWR Core Internals Material Samples (MRP-160) Non-Proprietary Version

    SciTech Connect

    M. E. Krug; R. P. Shogan

    2005-09-30

    Pressurised water reactor (PWR) cores operate under extreme envrionmental conditions due to coolant chemistry, operating temperature and neutron exposure. Extending the life of PWRs requires detailed knowledge of teh changes in mechanical and corrosion properties of teh structural austenitic stainless steel components adjacent to the fuel. This report contains results of fracture toughness testing of samples machined from decommissioned PWR reactor internals.

  8. Assessment of PWR Steam Generator modelling in RELAP5/MOD2. International Agreement Report

    SciTech Connect

    Putney, J.M.; Preece, R.J.

    1993-06-01

    An assessment of Steam Generator (SG) modelling in the PWR thermal-hydraulic code RELAP5/MOD2 is presented. The assessment is based on a review of code assessment calculations performed in the UK and elsewhere, detailed calculations against a series of commissioning tests carried out on the Wolf Creek PWR and analytical investigations of the phenomena involved in normal and abnormal SG operation. A number of modelling deficiencies are identified and their implications for PWR safety analysis are discussed -- including methods for compensating for the deficiencies through changes to the input deck. Consideration is also given as to whether the deficiencies will still be present in the successor code RELAP5/MOD3.

  9. Study on Equilibrium Characteristics of Thorium-Plutonium-Minor Actinides Mixed Oxides Fuel in PWR

    SciTech Connect

    Waris, A.; Permana, S.; Kurniadi, R.; Su'ud, Z.; Sekimoto, H.

    2010-06-22

    A study on characteristics of thorium-plutonium-minor actinides utilization in the pressurized water reactor (PWR) with the equilibrium burnup model has been conducted. For a comprehensive evaluation, several fuel cycles scenario have been included in the present study with the variation of moderator-to-fuel volume ratio (MFR) of PWR core design. The results obviously exhibit that the neutron spectra grow to be harder with decreasing of the MFR. Moreover, the neutron spectra also turn into harder with the rising number of confined heavy nuclides. The required {sup 233}U concentration for criticality of reactor augments with the increasing of MFR for all heavy nuclides confinement and thorium and uranium confinement in PWR.

  10. Coupled Neutronics Thermal-Hydraulic Solution of a Full-Core PWR Using VERA-CS

    SciTech Connect

    Clarno, Kevin T; Palmtag, Scott; Davidson, Gregory G; Salko, Robert K; Evans, Thomas M; Turner, John A; Belcourt, Kenneth; Hooper, Russell; Schmidt, Rodney

    2014-01-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is developing a core simulator called VERA-CS to model operating PWR reactors with high resolution. This paper describes how the development of VERA-CS is being driven by a set of progression benchmark problems that specify the delivery of useful capability in discrete steps. As part of this development, this paper will describe the current capability of VERA-CS to perform a multiphysics simulation of an operating PWR at Hot Full Power (HFP) conditions using a set of existing computer codes coupled together in a novel method. Results for several single-assembly cases are shown that demonstrate coupling for different boron concentrations and power levels. Finally, high-resolution results are shown for a full-core PWR reactor modeled in quarter-symmetry.

  11. Study on Equilibrium Characteristics of Thorium-Plutonium-Minor Actinides Mixed Oxides Fuel in PWR

    NASA Astrophysics Data System (ADS)

    Waris, A.; Permana, S.; Kurniadi, R.; Su'ud, Z.; Sekimoto, H.

    2010-06-01

    A study on characteristics of thorium-plutonium-minor actinides utilization in the pressurized water reactor (PWR) with the equilibrium burnup model has been conducted. For a comprehensive evaluation, several fuel cycles scenario have been included in the present study with the variation of moderator-to-fuel volume ratio (MFR) of PWR core design. The results obviously exhibit that the neutron spectra grow to be harder with decreasing of the MFR. Moreover, the neutron spectra also turn into harder with the rising number of confined heavy nuclides. The required 233U concentration for criticality of reactor augments with the increasing of MFR for all heavy nuclides confinement and thorium & uranium confinement in PWR.

  12. Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest

    NASA Astrophysics Data System (ADS)

    Norby, R. J.; Warren, J. M.; Iversen, C. M.; Medlyn, B. E.; McMurtrie, R. E.; Hoffman, F. M.

    2008-12-01

    Accurate model representation of the long-term response of forested ecosystems to elevated atmospheric CO2 concentrations (eCO2) is important for predictions of future concentrations of CO2. For biogeochemical models that predict the response of net primary productivity (NPP) to eCO2, free-air CO2 enrichment (FACE) experiments provide the only source of data for comparison. A synthesis of forest FACE experiments reported a 23% increase in NPP in eCO2, and this result has been used as a model benchmark. Here, we provide new evidence from a FACE experiment in a deciduous forest in Tennessee that N limitation has significantly reduced the stimulation of NPP by eCO2, consistent with predictions from ecosystem and global models that incorporate N feedbacks. The Liquidambar styraciflua stand has been exposed to current ambient atmospheric CO2 or air enriched with CO2 to 550 ppm since 1998. Results from the first 6 years of the experiment indicated that NPP was significantly enhanced by eCO2 and that this was a consistent and sustained response. Now, with 10 years of data, our analysis must be revised. The response of NPP to eCO2 has declined from 24% in 2001-2003 to 9% in 2007. The diminishing response to eCO2 since 2004 coincides with declining NPP in ambient CO2 plots. Productivity of this forest stand is limited by N availability, and the steady decline in forest NPP is closely related to changes in the N economy, as evidenced by declining foliar N concentrations. There is a strong linear relationship between foliar [N] and NPP, and the steeper slope in eCO2 indicates that the NPP response to eCO2 should diminish as foliar N declines. Increased fine-root production and root proliferation deeper in the soil have sustained N uptake, but not to an extent sufficient to benefit aboveground production. The mechanistic basis of the N effect on NPP resides in the photosynthetic machinery. The linear relationships between Jmax and Vcmax with foliar [N] did not change from 1998

  13. Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest

    SciTech Connect

    Norby, Richard J; Warren, Jeffrey; Iversen, Colleen M; Medlyn, Belinda; McMurtrie, Ross; Hoffman, Forrest M

    2008-01-01

    Accurate model representation of the long-term response of forested ecosystems to elevated atmospheric CO2 concentrations (eCO2) is important for predictions of future concentrations of CO2. For biogeochemical models that predict the response of net primary productivity (NPP) to eCO2, free-air CO2 enrichment (FACE) experiments provide the only source of data for comparison. A synthesis of forest FACE experiments reported a 23% increase in NPP in eCO2, and this result has been used as a model benchmark. Here, we provide new evidence from a FACE experiment in a deciduous forest in Tennessee that N limitation has significantly reduced the stimulation of NPP by eCO2, consistent with predictions from ecosystem and global models that incorporate N feedbacks. The Liquidambar styraciflua stand has been exposed to current ambient atmospheric CO2 or air enriched with CO2 to 550 ppm since 1998. Results from the first 6 years of the experiment indicated that NPP was significantly enhanced by eCO2 and that this was a consistent and sustained response. Now, with 10 years of data, our analysis must be revised. The response of NPP to eCO2 has declined from 24% in 2001-2003 to 9% in 2007. The diminishing response to eCO2 since 2004 coincides with declining NPP in ambient CO2 plots. Productivity of this forest stand is limited by N availability, and the steady decline in forest NPP is closely related to changes in the N economy, as evidenced by declining foliar N concentrations. There is a strong linear relationship between foliar [N] and NPP, and the steeper slope in eCO2 indicates that the NPP response to eCO2 should diminish as foliar N declines. Increased fine-root production and root proliferation deeper in the soil have sustained N uptake, but not to an extent sufficient to benefit aboveground production. The mechanistic basis of the N effect on NPP resides in the photosynthetic machinery. The linear relationships between Jmax and Vcmax with foliar [N] did not change from 1998

  14. Estimating cropland NPP using national crop inventory and MODIS derived crop specific parameters

    NASA Astrophysics Data System (ADS)

    Bandaru, V.; West, T. O.; Ricciuto, D. M.

    2011-12-01

    Estimates of cropland net primary production (NPP) are needed as input for estimates of carbon flux and carbon stock changes. Cropland NPP is currently estimated using terrestrial ecosystem models, satellite remote sensing, or inventory data. All three of these methods have benefits and problems. Terrestrial ecosystem models are often better suited for prognostic estimates rather than diagnostic estimates. Satellite-based NPP estimates often underestimate productivity on intensely managed croplands and are also limited to a few broad crop categories. Inventory-based estimates are consistent with nationally collected data on crop yields, but they lack sub-county spatial resolution. Integrating these methods will allow for spatial resolution consistent with current land cover and land use, while also maintaining total biomass quantities recorded in national inventory data. The main objective of this study was to improve cropland NPP estimates by using a modification of the CASA NPP model with individual crop biophysical parameters partly derived from inventory data and MODIS 8day 250m EVI product. The study was conducted for corn and soybean crops in Iowa and Illinois for years 2006 and 2007. We used EVI as a linear function for fPAR, and used crop land cover data (56m spatial resolution) to extract individual crop EVI pixels. First, we separated mixed pixels of both corn and soybean that occur when MODIS 250m pixel contains more than one crop. Second, we substituted mixed EVI pixels with nearest pure pixel values of the same crop within 1km radius. To get more accurate photosynthetic active radiation (PAR), we applied the Mountain Climate Simulator (MTCLIM) algorithm with the use of temperature and precipitation data from the North American Land Data Assimilation System (NLDAS-2) to generate shortwave radiation data. Finally, county specific light use efficiency (LUE) values of each crop for years 2006 to 2007 were determined by application of mean county inventory

  15. S-NPP OMPS Nadir In-Flight Performance

    NASA Astrophysics Data System (ADS)

    Pan, S.; Flynn, L. E.; Niu, J.; Grotenhuis, M.; Beck, C. T.; Beach, E.; Zhang, Z.; Tolea, A.

    2014-12-01

    This presentation describes the results of in-flight characterization of the S-NPP Ozone Mapping Profiler Suite (OMPS) charge-coupled device (CCD) performance during the first nearly three years of the OMPS mission in orbit. Data from OMPS's three two-dimension CCD arrays have been collected to characterize in-flight detector behaviors. Our results show that offset, gain, and dark current rate trends remain within sensor requirement limits. System linearity performance trends are stable. The distribution of individual pixel dark rates is slowly growing as expected from pre-launch analyses. The current in-flight dark and linearity calibration corrections provide Sensor Data Records (SDRs) with insignificant error after correction of less than an average of ~0.1% in the Earth radiance retrieval. The instrument optics is less stable than predicted leading to intra-orbit wavelength scale variations as the temperature gradients vary across the instrument. Measurement-based estimates of these effects are as large a ±0.02 nm and are used to make corrections to within +-0.005 nm on a granule by granule basis. Examination of reflectivity, aerosol and ozone EDRs provide evidence of absolute calibration errors with a significant cross track variation. A soft calibration adjustment is under development to remove them.

  16. Suomi NPP VIIRS Striping Analysis using Radiative Transfer Model Calculations

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Cao, C.

    2015-12-01

    Modern satellite radiometers such as VIIRS have many detectors with slightly different relative spectral response (RSR). These differences can introduce artifacts such as striping in the imagery. In recent studies we have analyzed the striping pattern related to the detector level RSR difference in VIIRS Thermal Emissive Bands (TEB) M15 and M16, which includes line-by-line radiative transfer model (LBLRTM) detector level response study and onboard detector stability evaluation using the solar diffuser. Now we extend these analysis to the Reflective Solar Bands (RSB) using MODTRAN atmospheric radiative transfer model (RTM) for detector level radiance simulation. Previous studies analyzed the striping pattern in the images of VIIRS ocean color and reflectance in RSB, further studies about the root cause for striping are still needed. In this study, we will use the MODTRAN model at spectral resolution of 1 cm^-1 under different atmospheric conditions for VIIRS RSB, for example band M1 centered at 410nm which is used for Ocean Color product retrieval. The impact of detector level RSR difference, atmospheric dependency, and solar geometry on the striping in VIIRS SDR imagery will be investigated. The cumulative histogram method used successfully for the TEB striping analysis will be used to quantify the striping. These analysis help S-NPP and J1 to better understand the root cause for VIIRS image artifacts and reduce the uncertainties in geophysical retrievals to meet the user needs.

  17. Derived Land Surface Emissivity From Suomi NPP CrIS

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu

    2012-01-01

    Presented here is the land surface IR spectral emissivity retrieved from the Cross-track Infrared Sounder (CrIS) measurements. The CrIS is aboard the Suomi National Polar-orbiting Partnership (NPP) satellite launched on October 28, 2011. We describe the retrieval algorithm, demonstrate the surface emissivity retrieved with CrIS measurements, and inter-comparison with the Infrared Atmospheric Sounding Interferometer (IASI) emissivity. We also demonstrate that surface emissivity from satellite measurements can be used in assistance of monitoring global surface climate change, as a long-term measurement of IASI and CrIS will be provided by the series of EUMETSAT MetOp and US Joint Polar Satellite System (JPSS) satellites. Monthly mean surface properties are produced using last 5-year IASI measurements. A temporal variation indicates seasonal diversity and El Nino/La Nina effects not only shown on the water but also on the land. Surface spectral emissivity and skin temperature from current and future operational satellites can be utilized as a means of long-term monitoring of the Earth's environment. CrIS spectral emissivity are retrieved and compared with IASI. The difference is small and could be within expected retrieval error; however it is under investigation.

  18. Impact of climate aggregation over different scales on regional NPP modelling

    NASA Astrophysics Data System (ADS)

    Kuhnert, Matthias

    2016-04-01

    Model input data aggregation methods and data aggregation across spatial scales affect various model outputs, e.g. Net Primary Productivity (NPP). The scale at which data is collected is of great importance. In ecosystem modelling studies we often see soil and climate data collected at coarse scale being used in models to predict ecosystem responses e.g. NPP in dependency of these parameters at finer scale. Outputs of these models are impacted by the way the data is aggregated or dis-aggregated to the spatial scale. Up to know there are very few studies which quantified the impact of scaling on the simulation results. In this study, we quantify the impact of climate data aggregation using five different resolutions, to simulate NPP by 11 different crop and biogeochemical models for the same study area. The aggregation effect is investigated for wheat and maize cropping systems in the state of North Rhine-Westphalia, Germany. The simulation results are analysed for NPP averaged over growing seasons of a 30 year period at different spatial resolutions as well as for annual NPP during growing season. While there is only a minor impact of input data aggregation on NPP on 30 year averages, the annual data show differences in NPP up to 9.4 % and 13.6 % between the different resolutions for wheat and maize, respectively. The scale effect differ between the models and shows higher impacts for extreme years. This is tested by selecting years with extreme dry conditions based on a drought index, which showed stronger scale effects of up to 12.8 % and 15.5 % for wheat and maize, respectively.

  19. Switching from deferred dismantling to immediate dismantling: the example of Chooz A, a French PWR

    SciTech Connect

    Grenouillet, Jean-Jacques

    2007-07-01

    Located in the north of France, close to Belgian border, Chooz A is the first PWR that was built in France from 1962 to 1967. When it was shutdown in 1991, a deferred dismantling strategy was selected. Further to an evolution of EDF decommissioning strategy in 2001, the decommissioning of the plant was accelerated by reducing the safe enclosure period to only a few years. Thus Chooz A will be the first PWR to be fully dismantled in France and it gives a good insight of what is needed to reactivate a plant for final dismantling after a safe enclosure period. (author)

  20. PWR containment structures license renewal industry report: Revision 1. Final report

    SciTech Connect

    Deng, D.; Renfro, J.; Statton, J.

    1994-07-01

    Reinforced concrete, prestressed concrete, and freestanding steel PWR containment structures and components have been evaluated relative to the effects of age-related degradation mechanisms; the capability of current design limits, inservice examination, testing, repair, refurbishment, and other programs to manage these effects; and the assurance that these structures and components can continue to perform their intended safety functions in the license renewal term. This industry report (IR), one of a series of ten, provides a generic technical basis for evaluation of PWR containment structures and components for license renewal.

  1. A GeoServices Infrastructure for Near-Real-Time Access to Suomi NPP Satellite Data

    NASA Astrophysics Data System (ADS)

    Evans, J. D.; Valente, E. G.; Hao, W.; Chettri, S.

    2012-12-01

    The new Suomi National Polar-orbiting Partnership (NPP) satellite extends NASA's moderate-resolution, multispectral observations with a suite of powerful imagers and sounders to support a broad array of research and applications. However, NPP data products consist of a complex set of data and metadata files in highly specialized formats; which NPP's operational ground segment delivers to users only with several hours' delay. This severely limits their use in critical applications such as weather forecasting, emergency / disaster response, search and rescue, and other activities that require near-real-time access to satellite observations. Alternative approaches, based on distributed Direct Broadcast facilities, can reduce the delay in NPP data delivery from hours to minutes, and can make products more directly usable by practitioners in the field. To assess and fulfill this potential, we are developing a suite of software that couples Direct Broadcast data feeds with a streamlined, scalable processing chain and geospatial Web services, so as to permit many more time-sensitive applications to use NPP data. The resulting geoservices infrastructure links a variety of end-user tools and applications to NPP data from different sources, and to other rapidly-changing geospatial data. By using well-known, standard software interfaces (such as OGC Web Services or OPeNDAP), this infrastructure serves a variety of end-user analysis and visualization tools, giving them access into datasets of arbitrary size and resolution and allowing them to request and receive tailored products on demand. The standards-based approach may also streamline data sharing among independent satellite receiving facilities, thus helping them to interoperate in providing frequent, composite views of continent-scale or global regions. To enable others to build similar or derived systems, the service components we are developing (based in part on the Community Satellite Processing Package (CSPP) from

  2. Temporal variability of the NPP-GPP ratio at seasonal and interannual time scales in a temperate beech forest

    NASA Astrophysics Data System (ADS)

    Campioli, M.; Gielen, B.; Göckede, M.; Papale, D.; Bouriaud, O.; Granier, A.

    2011-09-01

    The allocation of carbon (C) taken up by the tree canopy for respiration and production of tree organs with different construction and maintenance costs, life span and decomposition rate, crucially affects the residence time of C in forests and their C cycling rate. The carbon-use efficiency, or ratio between net primary production (NPP) and gross primary production (GPP), represents a convenient way to analyse the C allocation at the stand level. In this study, we extend the current knowledge on the NPP-GPP ratio in forests by assessing the temporal variability of the NPP-GPP ratio at interannual (for 8 years) and seasonal (for 1 year) scales for a young temperate beech stand, reporting dynamics for both leaves and woody organs, in particular stems. NPP was determined with biometric methods/litter traps, whereas the GPP was estimated via the eddy covariance micrometeorological technique. The interannual variability of the proportion of C allocated to leaf NPP, wood NPP and leaf plus wood NPP (on average 11% yr-1, 29% yr-1 and 39% yr-1, respectively) was significant among years with up to 12% yr-1 variation in NPP-GPP ratio. Studies focusing on the comparison of NPP-GPP ratio among forests and models using fixed allocation schemes should take into account the possibility of such relevant interannual variability. Multiple linear regressions indicated that the NPP-GPP ratio of leaves and wood significantly correlated with environmental conditions. Previous year drought and air temperature explained about half of the NPP-GPP variability of leaves and wood, respectively, whereas the NPP-GPP ratio was not decreased by severe drought, with large NPP-GPP ratio on 2003 due mainly to low GPP. During the period between early May and mid June, the majority of GPP was allocated to leaf and stem NPP, whereas these sinks were of little importance later on. Improved estimation of seasonal GPP and of the contribution of previous-year reserves to stem growth, as well as reduction

  3. Modification of the Decontamination Facility at the Kruemmel NPP - 13451

    SciTech Connect

    Klute, Stefan; Kupke, Peter

    2013-07-01

    In February 2009, Siempelkamp Nukleartechnik GmbH was awarded the contract for the design, manufacture, delivery and construction of a new Decontamination Facility in the controlled area for Kruemmel NPP. The new decontamination equipment has been installed according to the state of art of Kruemmel NPP. The existing space required the following modification, retrofitting and reconstruction works: - Demounting of the existing installation: to create space for the new facility it was necessary to dismantle the old facility. The concrete walls and ceilings were cut into sizes of no more than 400 kg for ease of handling. This enabled decontamination so largest possible amount could be released for recycling. All steel parts were cut into sizes fitting for iron-barred boxes, respecting the requirement to render the parts decontaminable and releasable. - Reconstructing a decontamination facility: Reconstruction of a decontamination box with separate air lock as access area for the decontamination of components and assemblies was conducted using pressurized air with abrasives (glass beads or steel shots). The walls were equipped with sound protection, the inner walls were welded gap-free to prevent the emergence of interstices and were equipped with changeable wear and tear curtains. Abrasive processing unit positioned underneath the dry blasting box adjacent to the two discharge hoppers. A switch has been installed for the separation of the glass beads and the steel shot. The glass beads are directed into a 200 l drum for the disposal. The steel shot was cleaned using a separator. The cleaned steel shot was routed via transportation devices to the storage container, making it available for further blasting operations. A decontamination box with separate air lock as access area for the decontamination of components and assemblies using high pressure water technology was provided by new construction. Water pressures between 160 bar and 800 bar can be selected. The inner

  4. Radioactive Waste Storage Facility at the Armenian NPP - 12462

    SciTech Connect

    Grigoryan, G.; Amirjanyan, A.; Gondakyan, Y.; Stepanyan, A.

    2012-07-01

    We present a detailed contaminant transfer dynamics model for radionuclide in geosphere and biosphere medium. The model describes the transport of radionuclides using full equation for the processes of advection, diffusion, decay and sorption. The overall objective is to establish, from a post-closure radiological safety point of view, whether it is practical to convert an existing radioactive waste storage facility at Armenian NPP, to a waste disposal facility. The calculation includes: - Data sources for: the operational waste-source term; options for refurbishment and completion of the waste storage facility as a waste disposal facility; the site and its environs; - Development of an assessment context for the safety assessment, and identification of waste treatment options; - A description of the conceptual and mathematical models, and results calculated for the base case scenario relating to the release of contaminants via the groundwater pathway and also precipitation especially important for this site. The results of the calculations showed that the peak individual dose is < 7 E-8 Sv/y arising principally from I-129 after 700 years post closure. Other significant radionuclides, in terms of their contribution to the total dose are I-129, Tc-99 and in little C-14 (U- 234 and Po-210 are not relevant). The study does not explore all issues that might be expected to be presented in a safety case for a near surface disposal facility it mainly focuses on post- closure dose impacts. Most emphasis has been placed on the development of scenarios and conceptual models rather than the presentation and analyses of results and confidence building (only deterministic results are presented). The calculations suggest that, from a perspective the conversion of the waste-storage facility is feasible such that all the predicted doses are well below internationally recognized targets, as well as provisional Armenian regulatory objectives. This conclusion applies to the disposal

  5. Radiation exposure to marine biota around the Fukushima Daiichi NPP.

    PubMed

    Keum, Dong-Kwon; Kim, Byeong-Ho; Lim, Kwang-Muk; Choi, Yong-Ho

    2014-05-01

    The dose rates for six marine organisms, pelagic fish, benthic fish, mollusks, crustaceans, macroalgae, and polychaete worms, representative in marine ecosystems, have been predicted by the equilibrium model with the measured seawater activity concentrations at three locations around the Fukushima Daiich nuclear power plant after the accident on March 11, 2011. Model prediction showed that total dose rates for the biota in the costal sea reached 4.8E4 μGy/d for pelagic fish, 3.6E6 μGy/d for crustaceans, 3.8E6 μGy/d for benthic fish, 5.2E6 μGy/d for macroalgae, 6.6E6 μGy/d for mollusks, and 8.0E6 μGy/d for polychaete worms. The predicted total dose rates remained above the UNSCEAR's (United Nations Scientific Committee on the Effect of Atomic Radiation) benchmark level (1.0E4 μGy/d for an individual aquatic organism), for only the initial short period, which seems to be insufficiently long to bring about any detrimental effect on the marine biota at the population level. Furthermore, the total dose rates for benthic fish and crustaceans approximated using the measured activity concentration of the biota and bottom sediment was well below the benchmark level. From these results, it may be concluded that the impact of the ionizing radiation on the marine biota around the Fukushima NPP as a consequence of the accident would be insignificant. PMID:24374805

  6. An Overview of Suomi NPP VIIRS Calibration Maneuvers

    NASA Technical Reports Server (NTRS)

    Butler, James J.; Xiong, Xiaoxiong; Barnes, Robert A.; Patt, Frederick S.; Sun, Junqiang; Chiang, Kwofu

    2012-01-01

    The first Visible Infrared Imager Radiometer Suite (VIIRS) instrument was successfully launched on-board the Suomi National Polar-orbiting Partnership (SNPP) spacecraft on October 28, 2011. Suomi NPP VIIRS observations are made in 22 spectral bands, from the visible (VIS) to the long-wave infrared (LWIR), and are used to produce 22 Environmental Data Records (EDRs) with a broad range of scientific applications. The quality of these VIIRS EDRs strongly depends on the quality of its calibrated and geo-located Sensor Date Records (SDRs). Built with a strong heritage to the NASA's EOS MODerate resolution Imaging Spectroradiometer (MODIS) instrument, the VIIRS is calibrated on-orbit using a similar set of on-board calibrators (OBC), including a solar diffuser (SD) and solar diffuser stability monitor (SDSM) system for the reflective solar bands (RSB) and a blackbody (BB) for the thermal emissive bands (TEB). On-orbit maneuvers of the SNPP spacecraft provide additional calibration and characterization data from the VIIRS instrument which cannot be obtained pre-launch and are required to produce the highest quality SDRs. These include multi-orbit yaw maneuvers for the characterization of SD and SDSM screen transmission, quasi-monthly roll maneuvers to acquire lunar observations to track sensor degradation in the visible through shortwave infrared, and a driven pitch-over maneuver to acquire multiple scans of deep space to determine TEB response versus scan angle (RVS). This paper pro-vides an overview of these three SNPP calibration maneuvers. Discussions are focused on their potential calibration and science benefits, pre-launch planning activities, and on-orbit scheduling and implementation strategies. Results from calibration maneuvers performed during the Intensive Calibration and Validation (ICV) period for the VIIRS sensor are illustrated. Also presented in this paper are lessons learned regarding the implementation of calibration spacecraft maneuvers on follow

  7. Nuclear power plant maintenance personnel reliability prediction (NPP/MPRP) effort at Oak Ridge National Laboratory

    SciTech Connect

    Knee, H.E.; Haas, P.M.; Siegel, A.I.

    1981-01-01

    Human errors committed during maintenance activities are potentially a major contribution to the overall risk associated with the operation of a nuclear power plant (NPP). An NRC-sponsored program at Oak Ridge National Laboratory is attempting to develop a quantitative predictive technique to evaluate the contribution of maintenance errors to the overall NPP risk. The current work includes a survey of the requirements of potential users to ascertain the need for and content of the proposed quantitative model, plus an initial job/task analysis to determine the scope and applicability of various maintenance tasks. In addition, existing human reliability prediction models are being reviewed and assessed with respect to their applicability to NPP maintenance tasks. This paper discusses the status of the program and summarizes the results to date.

  8. Satellite EDR Evaluation with First Suomi NPP Cal/Val Campaign

    NASA Astrophysics Data System (ADS)

    Zhou, D. K.; Liu, X.; Larar, A. M.; Tian, J.; Smith, W. L.; Wu, W.; Kizer, S.; Goldberg, M.; Liu, Q.

    2015-12-01

    Satellite ultraspectral infrared sensors provide key data records essential for weather forecasting and climate change science. The Suomi National Polar-orbiting Partnership (NPP) satellite Environmental Data Records (EDRs) are retrieved from calibrated ultraspectral radiance or Sensor Data Records (SDRs). Understand the accuracy of retrieved EDRs is critical. The first Suomi NPP Calibration/Validation Campaign was conducted during May 2013. The NASA high-altitude ER-2 aircraft carrying ultraspectral interferometer sounders such as the National Airborne Sounder Testbed-Interferometer (NAST-I) flew under the Suomi NPP satellite that carries the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS). Here, we inter-compare the EDRs produced with different retrieval algorithms from SDRs measured from satellite and aircraft. The available dropsonde and radiosonde measurements together with the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis are used to assess the results of this experiment.

  9. Decreased expression of ectonucleotidase E-NPP1 in leukocytes from subjects with severe asthma exacerbation.

    PubMed

    Montaño, L M; Vargas, M H; Díaz-Hernández, V; De Ita, M; Kazakova, R; Barajas-López, C

    2016-01-01

    Several studies suggest that ATP and related nucleotides play a role in the pathophysiology of asthma. However, the functionality of ectonucleotidases in this disease has been scantly investigated. We studied total ectonucleotidase activity in leukocytes from patients suffering from asthma exacerbation and explored the expression of E-NTPDase 1, 2, 3, and 8, and E-NPP1, 2, and 3, in their polymorphonuclear cells by immunofluorescence and qPCR. Leukocytes from patients with mild or moderate asthma exacerbation had similar ectonucleotidase activity than leukocytes from healthy subjects, while in patients with severe asthma exacerbation, this activity was lower. Of the ectonucleotidases studied, only E-NPP1 displayed diminished immunofluorescence and a significant decrease in its mRNA expression, both in patients with severe asthma exacerbation. This reduced E-NPP1 expression could be responsible for increased amounts of ATP or other nucleotides, capable of worsening asthma exacerbation, and warranting further investigation. PMID:26405014

  10. On the majority carrier collection in p+pn+ and n+pp+ silicon solar cells

    NASA Astrophysics Data System (ADS)

    Singh, S. N.; Kotnala, R. K.; Jain, G. C.

    The spectral responses of a few bifacial n+pp+ silicon solar cells of different thicknesses were measured to investigate the possibility of majority carrier collection in n+pp+ back surface field (BSF) and p+pn+ front surface field (FSF) silicon solar cells. It has been found out that under low level conditions, any appreciable collection of photogenerated majority carriers has to be field aided. Therefore, under low level conditions, a substantial contribution of hole collection to the photocurrent density of a p+pn+ or n+pp+ cell may come from the p+ or p region provided not only the concentration of photogenerated holes in that region is substantially large but there also exists an aiding built in electric field due to an impurity gradient. For high level conditions, however, holes can be collected from the uniformly doped p-base region with or without the help of an aiding electric field.

  11. Assessment of void swelling in austenitic stainless steel PWR core internals.

    SciTech Connect

    Chung, H. M.; Energy Technology

    2006-01-31

    As many pressurized water reactors (PWRs) age and life extension of the aged plants is considered, void swelling behavior of austenitic stainless steel (SS) core internals has become the subject of increasing attention. In this report, the available database on void swelling and density change of austenitic SSs was critically reviewed. Irradiation conditions, test procedures, and microstructural characteristics were carefully examined, and key factors that are important to determine the relevance of the database to PWR conditions were evaluated. Most swelling data were obtained from steels irradiated in fast breeder reactors at temperatures >385 C and at dose rates that are orders of magnitude higher than PWR dose rates. Even for a given irradiation temperature and given steel, the integral effects of dose and dose rate on void swelling should not be separated. It is incorrect to extrapolate swelling data on the basis of 'progressive compounded multiplication' of separate effects of factors such as dose, dose rate, temperature, steel composition, and fabrication procedure. Therefore, the fast reactor data should not be extrapolated to determine credible void swelling behavior for PWR end-of-life (EOL) or life-extension conditions. Although the void swelling data extracted from fast reactor studies is extensive and conclusive, only limited amounts of swelling data and information have been obtained on microstructural characteristics from discharged PWR internals or steels irradiated at temperatures and at dose rates comparable to those of a PWR. Based on this relatively small amount of information, swelling in thin-walled tubes and baffle bolts in a PWR is not considered a concern. As additional data and relevant research becomes available, the newer results should be integrated with existing data, and the worthiness of this conclusion should continue to be scrutinized. PWR baffle reentrant corners are the most likely location to experience high swelling rates, and

  12. Counter-regulatory phosphatases TNAP and NPP1 temporally regulate tooth root cementogenesis.

    PubMed

    Zweifler, Laura E; Patel, Mudita K; Nociti, Francisco H; Wimer, Helen F; Millán, Jose L; Somerman, Martha J; Foster, Brian L

    2015-03-01

    Cementum is critical for anchoring the insertion of periodontal ligament fibers to the tooth root. Several aspects of cementogenesis remain unclear, including differences between acellular cementum and cellular cementum, and between cementum and bone. Biomineralization is regulated by the ratio of inorganic phosphate (Pi) to mineral inhibitor pyrophosphate (PPi), where local Pi and PPi concentrations are controlled by phosphatases including tissue-nonspecific alkaline phosphatase (TNAP) and ectonucleotide pyrophosphatase/phosphodiesterase 1 (NPP1). The focus of this study was to define the roles of these phosphatases in cementogenesis. TNAP was associated with earliest cementoblasts near forming acellular and cellular cementum. With loss of TNAP in the Alpl null mouse, acellular cementum was inhibited, while cellular cementum production increased, albeit as hypomineralized cementoid. In contrast, NPP1 was detected in cementoblasts after acellular cementum formation, and at low levels around cellular cementum. Loss of NPP1 in the Enpp1 null mouse increased acellular cementum, with little effect on cellular cementum. Developmental patterns were recapitulated in a mouse model for acellular cementum regeneration, with early TNAP expression and later NPP1 expression. In vitro, cementoblasts expressed Alpl gene/protein early, whereas Enpp1 gene/protein expression was significantly induced only under mineralization conditions. These patterns were confirmed in human teeth, including widespread TNAP, and NPP1 restricted to cementoblasts lining acellular cementum. These studies suggest that early TNAP expression creates a low PPi environment promoting acellular cementum initiation, while later NPP1 expression increases PPi, restricting acellular cementum apposition. Alterations in PPi have little effect on cellular cementum formation, though matrix mineralization is affected. PMID:25504209

  13. Comparing the impacts of 2003 and 2010 heatwaves in NPP over Europe

    NASA Astrophysics Data System (ADS)

    Bastos, A.; Gouveia, C. M.; Trigo, R. M.; Running, S. W.

    2013-10-01

    In the last decade, Europe was stricken by two outstanding heatwaves, the 2003 event in Western Europe and the recent 2010 episode over Russia. Both extreme events were characterised by record-breaking temperatures, and widespread socio-economic impacts, including significant increments on mortality rates, decreases in crop production and in hydroelectric production. This work aims to assess the influence of both mega-heatwaves on vegetation carbon uptake, using yearly Net Primary Production (NPP) and monthly Net Photosynthesis (PsN) data derived from satellite imagery obtained from MODIS for the period 2000-2011. In 2010, markedly low productivity was observed over a very large area in Russia, at monthly, seasonal and yearly scales, falling below 50% of average NPP. This decrease in NPP in 2010 was far more intense than the one affecting Western Europe in 2003, which corresponded to 20-30% of the average, and affected a~much larger extent. Total NPP anomalies reached -19 Tg C for the selected regions in France during 2003 and -94 Tg C for western Russia in 2010, which corresponds almost to the magnitude of total NPP anomaly during 2010 for the whole Europe. Overall, the widespread negative PsN anomalies in both regions match the patterns of very high temperature values preceded by a long period of below-average precipitation, leading to strong soil moisture deficits, stressing the role of soil-atmosphere coupling. In the case of 2003 heatwave, results indicate a strong influence of moisture deficits coupled with high temperatures in the response of vegetation, while for the 2010 event very high temperatures appear to be the main driver of very low NPP.

  14. Improvement of Radwaste Management System at Bilibinskaya NPP in the Far North Conditions - 13456

    SciTech Connect

    Fedorov, Denis; Adamovich, Dmitry; Savkin, Alexander

    2013-07-01

    Since 2009 Bilibinskaya NPP is getting started to prepare to the decommissioning in the Far North conditions. Bilibinskaya NPP is located in the Far North of Russian Federation in Chukotka region. Since 1974 it operates 4 units EGP-6 with the capacity of 48 MW each. According to the contract, SIA Radon has performed the following works: - LLRW disposal safety analysis, - The technology of spent ion-exchanger and salt residue solidification is proposed, - Expected radwaste (till 2027) management economical analysis, - Technical proposals for LLRW and IRW management. (authors)

  15. Crack growth rates of nickel alloy welds in a PWR environment.

    SciTech Connect

    Alexandreanu, B.; Chopra, O. K.; Shack, W. J.; Energy Technology

    2006-05-31

    In light water reactors (LWRs), vessel internal components made of nickel-base alloys are susceptible to environmentally assisted cracking. A better understanding of the causes and mechanisms of this cracking may permit less conservative estimates of damage accumulation and requirements on inspection intervals. A program is being conducted at Argonne National Laboratory to evaluate the resistance of Ni alloys and their welds to environmentally assisted cracking in simulated LWR coolant environments. This report presents crack growth rate (CGR) results for Alloy 182 shielded-metal-arc weld metal in a simulated pressurized water reactor (PWR) environment at 320 C. Crack growth tests were conducted on 1-T compact tension specimens with different weld orientations from both double-J and deep-groove welds. The results indicate little or no environmental enhancement of fatigue CGRs of Alloy 182 weld metal in the PWR environment. The CGRs of Alloy 182 in the PWR environment are a factor of {approx}5 higher than those of Alloy 600 in air under the same loading conditions. The stress corrosion cracking for the Alloy 182 weld is close to the average behavior of Alloy 600 in the PWR environment. The weld orientation was found to have a profound effect on the magnitude of crack growth: cracking was found to propagate faster along the dendrites than across them. The existing CGR data for Ni-alloy weld metals have been compiled and evaluated to establish the effects of key material, loading, and environmental parameters on CGRs in PWR environments. The results from the present study are compared with the existing CGR data for Ni-alloy welds to determine the relative susceptibility of the specific Ni-alloy weld to environmentally enhanced cracking.

  16. Performance evaluation of two-stage fuel cycle from SFR to PWR

    SciTech Connect

    Fei, T.; Hoffman, E.A.; Kim, T.K.; Taiwo, T.A.

    2013-07-01

    One potential fuel cycle option being considered is a two-stage fuel cycle system involving the continuous recycle of transuranics in a fast reactor and the use of bred plutonium in a thermal reactor. The first stage is a Sodium-cooled Fast Reactor (SFR) fuel cycle with metallic U-TRU-Zr fuel. The SFRs need to have a breeding ratio greater than 1.0 in order to produce fissile material for use in the second stage. The second stage is a PWR fuel cycle with uranium and plutonium mixed oxide fuel based on the design and performance of the current state-of-the-art commercial PWRs with an average discharge burnup of 50 MWd/kgHM. This paper evaluates the possibility of this fuel cycle option and discusses its fuel cycle performance characteristics. The study focuses on an equilibrium stage of the fuel cycle. Results indicate that, in order to avoid a positive coolant void reactivity feedback in the stage-2 PWR, the reactor requires high quality of plutonium from the first stage and minor actinides in the discharge fuel of the PWR needs to be separated and sent back to the stage-1 SFR. The electricity-sharing ratio between the 2 stages is 87.0% (SFR) to 13.0% (PWR) for a TRU inventory ratio (the mass of TRU in the discharge fuel divided by the mass of TRU in the fresh fuel) of 1.06. A sensitivity study indicated that by increasing the TRU inventory ratio to 1.13, The electricity generation fraction of stage-2 PWR is increased to 28.9%. The two-stage fuel cycle system considered in this study was found to provide a high uranium utilization (>80%). (authors)

  17. The change of global terrestrial ecosystem net primary productivity (NPP) and its response to climate change in CMIP5

    NASA Astrophysics Data System (ADS)

    Li, Suosuo; Lü, Shihua; Zhang, Yongjun; Liu, Yuanpu; Gao, Yanhong; Ao, Yinhuan

    2015-07-01

    Using global terrestrial ecosystem observation and proxy data for net primary productivity (NPP), leaf area index (LAI), and climate data, we compared simulated NPP, LAI, and major climatic factors and explored the relationship between their variations in historical scenarios of ten Coupled Model Intercomparison Project (CMIP5) models. The results showed that global spatial patterns of the simulated terrestrial ecosystem and climate are consistent with proxy data, but the values have some differences for each model. Based on statistical analysis, the simulated climatic factors were found to be better than terrestrial ecosystem NPP and LAI, and the multi-model ensemble (MME) results were better than every single model. For the terrestrial ecosystem, air temperature (Ta) was found to be the major affecting factor, followed by precipitation, meaning the terrestrial ecosystem NPP and LAI are more related to Ta than precipitation. Meanwhile, surface downwelling shortwave radiation (Rsds) was found to inhibit the terrestrial ecosystem in almost all regions of the world. Between 1976 and 2005, precipitation had a slight increasing trend, Ta an obvious increasing trend, and Rsds a slight decreasing trend. The changes of precipitation, air temperature, and Rsds were favorable for the terrestrial ecosystem and for plant growth. Therefore, LAI and NPP showed an obvious increasing temporal trend, and the terrestrial ecosystem showed a positive response to climate change. All the model results showed NPP had an increasing temporal trend in the past 150 years, which also indicated that the terrestrial ecosystem has shown a positive response to climate change in that time period. In terms of the global average, the simulated NPP varied from 21.5 to 69.3 Pg C year-1, and the MME NPP is about 50.6, which was almost consistent with the International Geosphere Biosphere Program (IGBP) NPP result of 55.1 and Moderate Resolution Imaging Spectroradiometer (MODIS) NPP results of 60.5 Pg

  18. Artificial radionuclides in Russia due to the Fukushima NPP accident

    NASA Astrophysics Data System (ADS)

    Polianskaia, Olga; Vakulovsky, Sergey; Kim, Vera; Yahryushin, Valery; Volokitin, Andrey

    2013-04-01

    Radioactive emission into the atmosphere from the damaged reactors of the Fukushima Daiichi nuclear power plant (NPP) started on March 12th, 2011. The network of Federal Hydrometeorology and Environmental Monitoring Service (Rosgydromet) carries out supervision over a radiation situation on the territory of Russia. In Russia, the first radionuclides from Fukushima were detected on March 20th in the Far East by network. From March 20th to April 30th I-131 (particulate form), Cs-137 and Cs-134 were detected in samples of atmospheric aerosols at the 30 stations of networks and the same ones were detected in fallout at the 25 stations of networks. The first detection of I-131 in the European territory of Russia (ETR) occurred on March 23rd; and in the South and the North of Siberia - on March 26th. The volumetric activities of I-131 in the ETR sharply increased from March 28th to 30th. Along with the increasing content of I-131 cesium isotopes appeared in the air. The maximum values of radionuclides volume activity were observed between April 3rd and 4th: for I-131 - 4,0 mBq/m3, for Cs-137 - 1,15 mBq/m3, for Cs-134 - 1,04 mBq/m3. Observed in the Far East, the maximum values for I-131 were 2-4 times lower than in the ETR. The maximum values for I-131 in the Asian territory of Russia (ATR) were 2 - 8 times lower, than in the ETR. The Cs-137/Cs-134 ratio in samples of atmospheric aerosols was about 1. The ratio I-131/Cs-137 in air changed in a wide range. From March 23rd to April 5th the ratio fluctuated within 11 to 34, from April 5th to 20th of the ratio decreased and varied within 1,5 to 7,7, further it became less than 1. The value of cesium isotopes in second quarter of 2011 in fallout was lower than 2 Bq/m2. The addition to the density of soil contamination by Cs-137 by 2 to 3 orders of magnitude less than the decrease of the density of contamination with this isotope of the global origin due to radioactive decay. Based on the obtained experimental data we can

  19. Ageing management of french NPP civil work structures

    NASA Astrophysics Data System (ADS)

    Gallitre, E.; Dauffer, D.

    2011-04-01

    This paper presents EDF practice about concrete structure ageing management, from the mechanisms analysis to the formal procedure which allows the French company to increase 900 MWe NPP lifetime until 40 years; it will also introduce its action plan for 60 years lifetime extension. This practice is based on a methodology which identifies every ageing mechanism; both plants feedback and state of the art are screened and conclusions are drawn up into an "ageing analysis data sheet". That leads at first to a collection of 57 data sheets which give the mechanism identification, the components that are concerned and an analysis grid which is designed to assess the safety risk. This analysis screens the reference documents describing the mechanism, the design lifetime hypotheses, the associated regulation or codification, the feedback experiences, the accessibility, the maintenance actions, the repair possibility and so one. This analysis has to lead to a conclusion about the risk taking into account monitoring and maintenance. If the data sheet conclusion is not clear enough, then a more detailed report is launched. The technical document which is needed, is a formal detailed report which summarizes every theoretical knowledge and monitoring data: its objective is to propose a solution for ageing management: this solution can include more inspections or specific research development, or additional maintenance. After a first stage on the 900 MWe units, only two generic ageing management detailed reports have been needed for the civil engineering part: one about reactor building containment, and one about other structures which focuses on concrete inflating reactions. The second stage consists on deriving this generic analysis (ageing mechanism and detailed reports) to every plant where a complete ageing report is required (one report for all equipments and structures of the plant, but specific for each reactor). This ageing management is a continuous process because the

  20. Current Status of Suomi NPP VIIRS Aerosol Products

    NASA Astrophysics Data System (ADS)

    Kondragunta, S.; Laszlo, I.; Liu, H.; Zhang, H.; Huang, J.; Remer, L. A.; Ciren, P.; Huang, H.

    2013-12-01

    The Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched on October 28, 2011. It provides Aerosol Optical Thickness (AOT) at two different spatial resolutions: a pixel level (~750 m at nadir) product called the Intermediate Product (IP) and an aggregated (~6 km at nadir) product called the Environmental Data Record (EDR). The VIIRS AOT is expected to provide continuity to the 10-km Aqua and Terra MODIS (Moderate resolution Imaging Spectroradiometer) AOT products that the air quality and public health community has been using. The VIIRS aerosol product suite also includes less mature products such as Suspended Matter (SM) and Aerosol Particle Size Parameter (APSP). An extensive validation of VIIRS best quality aerosol products with ground based L1.5 AERONET data shows that the AOT EDR product has an accuracy/precision of -0.01/0.11 and 0.01/0.08 over land and ocean respectively. Globally, VIIRS mean AOT EDR (0.20) is similar to Aqua MODIS (0.16) with some important regional and seasonal differences. Analysis of SM shows that the algorithm predominantly picks smoke both over land and ocean which is not in agreement with retrievals from Multi-angle Imaging SpectroRadiometer (MISR) and Cloud Aerosol Lidar and Infrared Pathfinder Space Observations (CALIPSO). Similarly, the Angstrom Exponent (AE) retrieval used as a proxy for particle size has no skill over land and only a marginal skill over ocean when compared to AERONET; although a bias of ~0.2 for over ocean retrievals meets specification (0.3), the correlation is low and the standard deviation is ~0.6 and does not meet specification (0.3). This evaluation places the VIIRS AOT product at the provisional maturity level (product is validated, may contain some errors, and ready for operational evaluation). However, several algorithm updates which include a better approach to retrieve surface reflectance are forthcoming. Current status of the aerosol

  1. Proceedings: 1983 Workshop on Secondary-Side Stress Corrosion Cracking and Intergranular Corrosion of PWR Steam Generator Tubing

    SciTech Connect

    1986-03-01

    Participants in this international workshop discussed research investigating mechanisms and propagation rates of intergranular corrosion in PWR steam generators. Laboratory test results, which have been consistent with power plant experience, permitted preliminary definition of corrosion rates in alloy 600 tubing.

  2. Simulation of Hydrogen Distribution in Ignalina NPP ALS Compartments During BDBA

    SciTech Connect

    Babilas, Egidijus; Urbonavicius, Egidijus; Rimkevicius, Sigitas

    2006-07-01

    Accident Localisation System (ALS) of Ignalina NPP is a 'pressure suppression' type confinement, which protects the population, employees and environment from the radiation hazards. According to the Safety Analysis Report for Ignalina NPP {approx}110 m{sup 3} of hydrogen is released to ALS compartments during the Maximum Design Basis Accident. However in case of beyond design basis accident, when the oxidation of zirconium starts, the amount of generated hydrogen could be significantly higher. If the volume concentration of hydrogen in the compartment reaches 4%, there is a possibility for a combustible mixture to appear. To prevent the possible hydrogen accumulation in the ALS of the Ignalina NPP during an accident the H{sub 2} control system is installed. The results of the performed analysis derived the places of the possible H{sub 2} accumulation in the ALS compartments during the transient processes and assessed the mixture combustibility in these places for a beyond design basis accident scenario. Such analysis of H{sub 2} distribution in the ALS of Ignalina NPP in case of BDBA was not performed before. (authors)

  3. [Specific Features of Scots Pine Seeds Formation in the Remote Period after the Chernobyl NPP Accident].

    PubMed

    Geras'kin, S A; Vasiliev, D V; Kuzmenkov, A G

    2015-01-01

    The results of long-term (2007-2011) observations on the quality of seed progeny in Scots pine populations inhabiting the sites within the Bryansk region contaminated as a result of the Chernobyl NPP accident are presented. Formed under the chronic exposure seeds are characterized by a high interannual variability, which is largely determined by weather conditions. PMID:26863784

  4. Evaluation of Radiation Impacts of Spent Nuclear Fuel Storage (SNFS-2) of Chernobyl NPP - 13495

    SciTech Connect

    Paskevych, Sergiy; Batiy, Valiriy; Sizov, Andriy; Schmieman, Eric

    2013-07-01

    Radiation effects are estimated for the operation of a new dry storage facility for spent nuclear fuel (SNFS-2) of Chernobyl NPP RBMK reactors. It is shown that radiation exposure during normal operation, design and beyond design basis accidents are minor and meet the criteria for safe use of radiation and nuclear facilities in Ukraine. (authors)

  5. Deficiency of the bone mineralization inhibitor NPP1 protects mice against obesity and diabetes

    PubMed Central

    Huesa, Carmen; Zhu, Dongxing; Glover, James D.; Ferron, Mathieu; Karsenty, Gerard; Milne, Elspeth M.; Millan, José Luis; Ahmed, S. Faisal; Farquharson, Colin; Morton, Nicholas M.; MacRae, Vicky E.

    2014-01-01

    The emergence of bone as an endocrine regulator has prompted a re-evaluation of the role of bone mineralization factors in the development of metabolic disease. Ectonucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) controls bone mineralization through the generation of pyrophosphate, and levels of NPP1 are elevated both in dermal fibroblast cultures and muscle of individuals with insulin resistance. We investigated the metabolic phenotype associated with impaired bone metabolism in mice lacking the gene that encodes NPP1 (Enpp1−/− mice). Enpp1−/− mice exhibited mildly improved glucose homeostasis on a normal diet but showed a pronounced resistance to obesity and insulin resistance in response to chronic high-fat feeding. Enpp1−/− mice had increased levels of the insulin-sensitizing bone-derived hormone osteocalcin but unchanged insulin signalling within osteoblasts. A fuller understanding of the pathways of NPP1 could inform the development of novel therapeutic strategies for treating insulin resistance. PMID:25368121

  6. Post-Launch Calibration Support for VIIRS Onboard NASA NPP Spacecraft

    NASA Technical Reports Server (NTRS)

    Xiong, Xiaoxion; Chiang, Kwo-Fu; McIntire, Jeffrey; Schwaller, Matthew; Butler, James

    2011-01-01

    The NPP Instrument Calibration Support Element (NICSE) is one of the elements within the NASA NPP Science Data Segment (SDS). The primary responsibility of NICSE is to independently monitor and evaluate on-orbit radiometric and geometric performance of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument and to validate its Sensor Data Record (SDR) [1]. The NICSE interacts and works closely with other SDS Product Evaluation and Analysis Tools Elements (PEATE) and the NPP Science Team (ST) and supports their on-orbit data product calibration and validation efforts. The NICSE also works closely with the NPP Instrument Calibration Support Team (NICST) during sensor pre-launch testing in ambient and thermal vacuum environment [2]. This paper provides an overview of NICSE VIIRS sensor post-launch calibration support with a focus on the use of sensor on-board calibrators (OBC) for the radiometric calibration and characterization. It presents the current status of NICSE post-launch radiometric calibration tool development effort based on its design requirements

  7. Local network deployed around the Kozloduy NPP - a useful tool for seismological monitoring

    NASA Astrophysics Data System (ADS)

    Solakov, Dimcho; Simeonova, Stela; Dimitrova, Liliya; Slavcheva, Krasimira; Raykova, Plamena; Popova, Maria; Georgiev, Ivan

    2015-04-01

    Radiation risks may transcend national borders, and international cooperation serves to promote and enhance safety globally by exchanging experience and by improving capabilities to control hazards, to prevent accidents, to respond to emergencies and to mitigate any harmful consequences. International safety standards provide support for states in meeting their obligations under general principles of international law, such as those relating to environmental protection. Seismic safety is a key element of NPP safe operation. Safety and security measures have in common the aim of protecting human life and health and the environment. The Kozloduy NPP site is located in the stable part of the Moesian platform (area of about 50000 km2). From seismological point of view the Moesian platform is the most quite area on the territory of Bulgaria. There are neither historical nor instrumental earthquakes with M>4.5 occurred within the platform. The near region (area with radial extent of 30 km) of the NPP site is characterized with very low seismic activity. The strongest recorded quake is the 1987 earthquake МS=3.6, localized 22 km northwest of the Kozloduy NPP site on the territory of Romania. In line with international practice, the geological, geophysical and seismological characteristics of the region around the site have been investigated for the purpose of evaluating the seismic hazards at the NPP site. A local network (LSN) of sensitive seismographs having a recording capability for micro-earthquakes have been installed around Kozloduy NPP and operated since 1997. The operation and data processing, data interpretation, and reporting of the local micro-earthquake network are linked to the national seismic network (NOTSSI). A real-time data transfer from stations to National Data Center (in Sofia) was implemented using the VPN and MAN networks of the Bulgarian Telecommunication. Real-time and interactive data processing are performed by the Seismic Network Data

  8. The sensitivity of NPP to climate controls in northern China estimated by CLM model coupled with RS and GIS technology

    NASA Astrophysics Data System (ADS)

    Gao, Zhiqiang; Gao, Wei; Slusser, James R.; Pan, Xiaoling; Ma, Yingjun

    2003-07-01

    The continuing rise in atmospheric CO2 is considered as a main cause of the future changes in global climate. Predicted climate changes include an increase in mean annual air temperature and alterations in precipitation pattern and cloud cover. Net primary productivity (NPP) measures products of major economic and social importance, such as agricultural crop yield and forest production. It is important to understand the response of vegetation to the possible climate changes. While the Global NPP is hard to be measured directly, its global spatial and temporal dynamics can be investigated by a combination of ecosystem process modeling and monitoring by remote sensing (RS). NPP has been linked to climatic patterns by approaches ranging from simple correlations to sophisticated simulation models. This study was conducted in a range where the productivity and climate exist along an east-west transect in northern China. We used modified Common Land Surface Model (CLM) to simulate the NPP combined with satellite data and assessed the response of NPP under different climate change controls with different land surface vegetation types in study areas. The feasibility of the CLM model was tested and parameterized based on the ecological characteristics. The response of NPP to increased temperature was more sensitive to the doubled CO2 climate because the temperature is the limited factor to vegetation growth in study areas. The responses of NPP to different climate controls were also influenced by different vegetation types and ecological characteristics.

  9. Decontamination of the Shaft no.1 and cleaning container of 2. block NPP Paks

    SciTech Connect

    Bolcha, Jan; Mala, Zuzana; Tilky, Peter

    2007-07-01

    Available in abstract form only. Full text of publication follows: Meanwhile cleaning fuel assemblies on Paks NPP Unit 2. in 2003 year, the fuel assemblies were damaged, followed by contamination of cleaning container and operating shaft No. 1., in which was the container. As a part of the task - to restore operation NPP Paks, Unit 2, VUJE and.. realized decontamination of the wall of shaft prior to withdrawal of the defected fuel, decontamination of cleaning tank and in consequence decontamination of full shaft No. 1. Solution rest at finished conceptual decontamination proposal, fabrication of special purpose furnished, necessary documentation according to national legislative exigency. Real facilities on decontamination were examined on the stand and on shaft No. 1 in real conditions. This paper describes access method decontaminating procedure, applied facilities assigned on decontamination and present achievement results from decontamination shaft No. 1 realized in August 2006 and February 2007, respectively. Decontamination procedures were chosen on the base of experiments realized in laboratories VUJE and in Paks NPP. Laboratory experiments were realized on the sample of tube used for measurement of neutron flow, from NPP Paks, located in the shaft No.1 in time of event (INES-3). In NPP Paks were realized experiments on cover of cleaning container, which was in time of event situated on cleaning container. To compare decontaminated factors, the chemical and electrochemical procedures for decontamination were tested, and most effective practices were selected. Equipment ROS-740 can be used for the top part of the shaft decontamination. It allows high-pressure admission, rinse and chemical decontamination. Manipulator MAOS-170 is assigned for high-pressure admission of central part of the shaft. (authors)

  10. Decay Heat Calculations for PWR and BWR Assemblies Fueled with Uranium and Plutonium Mixed Oxide Fuel using SCALE

    SciTech Connect

    Ade, Brian J; Gauld, Ian C

    2011-10-01

    In currently operating commercial nuclear power plants (NPP), there are two main types of nuclear fuel, low enriched uranium (LEU) fuel, and mixed-oxide uranium-plutonium (MOX) fuel. The LEU fuel is made of pure uranium dioxide (UO{sub 2} or UOX) and has been the fuel of choice in commercial light water reactors (LWRs) for a number of years. Naturally occurring uranium contains a mixture of different uranium isotopes, primarily, {sup 235}U and {sup 238}U. {sup 235}U is a fissile isotope, and will readily undergo a fission reaction upon interaction with a thermal neutron. {sup 235}U has an isotopic concentration of 0.71% in naturally occurring uranium. For most reactors to maintain a fission chain reaction, the natural isotopic concentration of {sup 235}U must be increased (enriched) to a level greater than 0.71%. Modern nuclear reactor fuel assemblies contain a number of fuel pins potentially having different {sup 235}U enrichments varying from {approx}2.0% to {approx}5% enriched in {sup 235}U. Currently in the United States (US), all commercial nuclear power plants use UO{sub 2} fuel. In the rest of the world, UO{sub 2} fuel is still commonly used, but MOX fuel is also used in a number of reactors. MOX fuel contains a mixture of both UO{sub 2} and PuO{sub 2}. Because the plutonium provides the fissile content of the fuel, the uranium used in MOX is either natural or depleted uranium. PuO{sub 2} is added to effectively replace the fissile content of {sup 235}U so that the level of fissile content is sufficiently high to maintain the chain reaction in an LWR. Both reactor-grade and weapons-grade plutonium contains a number of fissile and non-fissile plutonium isotopes, with the fraction of fissile and non-fissile plutonium isotopes being dependent on the source of the plutonium. While only RG plutonium is currently used in MOX, there is the possibility that WG plutonium from dismantled weapons will be used to make MOX for use in US reactors. Reactor-grade plutonium

  11. Thiazolo[3,2-a]benzimidazol-3(2H)-one derivatives: Structure-activity relationships of selective nucleotide pyrophosphatase/phosphodiesterase1 (NPP1) inhibitors.

    PubMed

    Lee, Sang-Yong; Perotti, Arianna; De Jonghe, Steven; Herdewijn, Piet; Hanck, Theodor; Müller, Christa E

    2016-07-15

    Ecto-nucleotide pyrophosphatase/phosphodiesterase1 (NPP1) is the most important member of the NPP family, which consists of seven closely related proteins (NPP1-NPP7). This glycoprotein is a membrane-associated or secreted enzyme, which catalyzes the hydrolysis of a wide range of phosphodiester bonds, e.g., in nucleoside triphosphates, dinucleotides and nucleotide sugars. NPP1 plays a crucial role in various physiological functions including bone mineralization, soft-tissue calcification, and insulin receptor signaling. Recently, an upregulated expression of NPP1 has been observed in astrocytic brain cancers. Therefore, NPP1 has been proposed as a novel drug target for the treatment of glioblastoma. Despite their therapeutic potential, only few NPP1 inhibitors have been reported to date, which are in most cases non- or only moderately selective. The best investigated NPP1 inhibitors so far are nucleotide derivatives and analogs, however they are not orally bioavailable due to their high polarity. We identified thiazolo[3,2-a]benzimidazol-3(2H)-one derivatives as a new class of NPP1 inhibitors with drug-like properties. Among the 25 derivatives investigated in the present study, 2-[(5-iodo-2-furanyl)methylene]thiazolo[3,2-a]benzimidazol-3(2H)-one (17) was found to be the most potent NPP1 inhibitor with a Ki value of 467nM versus ATP as a substrate and an un-competitive mechanism of inhibition. Compound 17 did not inhibit other human ecto-nucleotidases, including NTPDase1 (CD39), NTPDases2-3, NPP2, NPP3, tissue-nonspecific alkaline phosphatase (TNAP), and ecto-5'-nucleotidase (eN, CD73), and is thus highly selective for NPP1. PMID:27265686

  12. Pressure-vessel-damage fluence reduction by low-leakage fuel management. [PWR

    SciTech Connect

    Cokinos, D.; Aronson, A.L.; Carew, J.F.; Kohut, P.; Todosow, M.; Lois, L.

    1983-01-01

    As a result of neutron-induced radiation damage to the pressure vessel and of an increased concern that in a PWR transient the pressure vessel may be subjected to pressurized thermal shock (PTS), detailed analyses have been undertaken to determine the levels of neutron fluence accumulation at the pressure vessels of selected PWR's. In addition, various methods intended to limit vessel damage by reducing the vessel fluence have been investigated. This paper presents results of the fluence analysis and the evaluation of the low-leakage fuel management fluence reduction method. The calculations were performed with DOT-3.5 in an octant of the core/shield/vessel configuration using a 120 x 43 (r, theta) mesh structure.

  13. The electrochemistry in 316SS crevices exposed to PWR-relevant conditions

    NASA Astrophysics Data System (ADS)

    Vankeerberghen, M.; Weyns, G.; Gavrilov, S.; Henshaw, J.; Deconinck, J.

    2009-04-01

    The chemical and electrochemical conditions within a crevice of Type 316 stainless steel in boric acid-lithium hydroxide solutions under PWR-relevant conditions were modelled with a computational electrochemistry code. The influence of various variables: dissolved hydrogen, boric acid, lithium hydroxide concentration, crevice length, and radiation dose rate was studied. It was found with the model that 25 ccH 2/kg (STP) was sufficient to remain below an electrode potential of -230 mV she, commonly accepted sufficient to prevent stress corrosion cracking under BWR conditions. In a PWR plant various operational B-Li cycles are possible but it was found that the choice of the cycle did not significantly influence the model results. It was also found that a hydrogen level of 50 ccH 2/kg (STP) would be needed to avoid substantial lowering of the pH inside a crevice.

  14. MC21 analysis of the MIT PWR benchmark: Hot zero power results

    SciTech Connect

    Kelly Iii, D. J.; Aviles, B. N.; Herman, B. R.

    2013-07-01

    MC21 Monte Carlo results have been compared with hot zero power measurements from an operating pressurized water reactor (PWR), as specified in a new full core PWR performance benchmark from the MIT Computational Reactor Physics Group. Included in the comparisons are axially integrated full core detector measurements, axial detector profiles, control rod bank worths, and temperature coefficients. Power depressions from grid spacers are seen clearly in the MC21 results. Application of Coarse Mesh Finite Difference (CMFD) acceleration within MC21 has been accomplished, resulting in a significant reduction of inactive batches necessary to converge the fission source. CMFD acceleration has also been shown to work seamlessly with the Uniform Fission Site (UFS) variance reduction method. (authors)

  15. Optimization of small long-life PWR based on thorium fuel

    SciTech Connect

    Subkhi, Moh Nurul; Suud, Zaki Waris, Abdul; Permana, Sidik

    2015-09-30

    A conceptual design of small long-life Pressurized Water Reactor (PWR) using thorium fuel has been investigated in neutronic aspect. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.2, while the multi-energy-group diffusion calculations were optimized in three-dimension X-Y-Z geometry of core by COREBN. The excess reactivity of thorium nitride with ZIRLO cladding is considered during 5 years of burnup without refueling. Optimization of 350 MWe long life PWR based on 5% {sup 233}U & 2.8% {sup 231}Pa, 6% {sup 233}U & 2.8% {sup 231}Pa and 7% {sup 233}U & 6% {sup 231}Pa give low excess reactivity.

  16. Conceptual design study of small long-life PWR based on thorium cycle fuel

    NASA Astrophysics Data System (ADS)

    Subkhi, M. Nurul; Su'ud, Zaki; Waris, Abdul; Permana, Sidik

    2014-09-01

    A neutronic performance of small long-life Pressurized Water Reactor (PWR) using thorium cycle based fuel has been investigated. Thorium cycle which has higer conversion ratio in thermal region compared to uranium cycle produce some significant of 233U during burn up time. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.3, while the multi-energy-group diffusion calculations were optimized in whole core cylindrical two-dimension R-Z geometry by SRAC-CITATION. this study would be introduced thorium nitride fuel system which ZIRLO is the cladding material. The optimization of 350 MWt small long life PWR result small excess reactivity and reduced power peaking during its operation.

  17. Optimization of small long-life PWR based on thorium fuel

    NASA Astrophysics Data System (ADS)

    Subkhi, Moh Nurul; Suud, Zaki; Waris, Abdul; Permana, Sidik

    2015-09-01

    A conceptual design of small long-life Pressurized Water Reactor (PWR) using thorium fuel has been investigated in neutronic aspect. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.2, while the multi-energy-group diffusion calculations were optimized in three-dimension X-Y-Z geometry of core by COREBN. The excess reactivity of thorium nitride with ZIRLO cladding is considered during 5 years of burnup without refueling. Optimization of 350 MWe long life PWR based on 5% 233U & 2.8% 231Pa, 6% 233U & 2.8% 231Pa and 7% 233U & 6% 231Pa give low excess reactivity.

  18. Conceptual design study of small long-life PWR based on thorium cycle fuel

    SciTech Connect

    Subkhi, M. Nurul; Su'ud, Zaki; Waris, Abdul; Permana, Sidik

    2014-09-30

    A neutronic performance of small long-life Pressurized Water Reactor (PWR) using thorium cycle based fuel has been investigated. Thorium cycle which has higher conversion ratio in thermal region compared to uranium cycle produce some significant of {sup 233}U during burn up time. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.3, while the multi-energy-group diffusion calculations were optimized in whole core cylindrical two-dimension R-Z geometry by SRAC-CITATION. this study would be introduced thorium nitride fuel system which ZIRLO is the cladding material. The optimization of 350 MWt small long life PWR result small excess reactivity and reduced power peaking during its operation.

  19. DOMINO: A fast 3D cartesian discrete ordinates solver for reference PWR simulations and SPN validation

    SciTech Connect

    Courau, T.; Moustafa, S.; Plagne, L.; Poncot, A.

    2013-07-01

    As part of its activity, EDF R and D is developing a new nuclear core simulation code named COCAGNE. This code relies on DIABOLO, a Simplified PN (SPN) method to compute the neutron flux inside the core for eigenvalue calculations. In order to assess the accuracy of SPN calculations, we have developed DOMINO, a new 3D Cartesian SN solver. The parallel implementation of DOMINO is very efficient and allows to complete an eigenvalue calculation involving around 300 x 10{sup 9} degrees of freedom within a few hours on a single shared-memory supercomputing node. This computation corresponds to a 26-group S{sub 8} 3D PWR core model used to assess the SPN accuracy. At the pin level, the maximal error for the SP{sub 5} DIABOLO fission production rate is lower than 0.2% compared to the S{sub 8} DOMINO reference for this 3D PWR core model. (authors)

  20. Preliminary assessment of PWR Steam Generator modelling in RELAP5/MOD3. International Agreeement Report

    SciTech Connect

    Preece, R.J.; Putney, J.M.

    1993-07-01

    A preliminary assessment of Steam Generator (SG) modelling in the PWR thermal-hydraulic code RELAP5/MOD3 is presented. The study is based on calculations against a series of steady-state commissioning tests carried out on the Wolf Creek PWR over a range of load conditions. Data from the tests are used to assess the modelling of primary to secondary side heat transfer and, in particular, to examine the effect of reverting to the standard form of the Chen heat transfer correlation in place of the modified form applied in RELAP5/MOD2. Comparisons between the two versions of the code are also used to show how the new interphase drag model in RELAP5/MOD3 affects the calculation of SG liquid inventory and the void fraction profile in the riser.

  1. Safety analysis of B and W Standard PWR using thorium-based fuels

    SciTech Connect

    Uotinen, V.O.; Carroll, W.P.; Jones, H.M.; Toops, E.C.

    1980-06-01

    A study was performed to assess the safety and licenseability of the Babcock and Wilcox standard 205-fuel assembly PWR when it is fueled with three types of thoria-based fuels denatured (/sup 233/U//sup 238/U-Th)O/sub 2/, denatured (/sup 235//U/sup 238/U-Th)O/sub 2/, and (Th-Pu)O/sub 2/. Selected transients were analyzed using typical PWR safety analysis calculational methods. The results support the conclusion that it is feasible from a safety standpoint to utilize either of the denatured urania-thoria fuels in the standard B and W plant. In addition, it appears that the use of thoria-plutonia fuels would probably also be feasible. These tentative conclusions depend on a data that is more limited than that available for UO/sub 2/ fuels.

  2. Radiation dose rates from commercial PWR and BWR spent fuel elements

    SciTech Connect

    Willingham, C.E.

    1981-10-01

    Data on measurements of gamma dose rates from commercial reactor spent fuel were collected, and documented calculated gamma dose rates were reviewed. As part of this study, the gamma dose rate from spent fuel was estimated, using computational techniques similar to previous investigations into this problem. Comparison of the measured and calculated dose rates provided a recommended dose rate in air versus distance curve for PWR spent fuel.

  3. MELCOR model for an experimental 17x17 spent fuel PWR assembly.

    SciTech Connect

    Cardoni, Jeffrey

    2010-11-01

    A MELCOR model has been developed to simulate a pressurized water reactor (PWR) 17 x 17 assembly in a spent fuel pool rack cell undergoing severe accident conditions. To the extent possible, the MELCOR model reflects the actual geometry, materials, and masses present in the experimental arrangement for the Sandia Fuel Project (SFP). The report presents an overview of the SFP experimental arrangement, the MELCOR model specifications, demonstration calculation results, and the input model listing.

  4. PWR ENDF/B-VII cross-section libraries for ORIGEN-ARP

    SciTech Connect

    McGraw, C.; Ilas, G.

    2012-07-01

    New pressurized water reactor (PWR) cross-section libraries were generated for use with the ORIGEN-ARP depletion sequence in the SCALE nuclear analysis code system. These libraries are based on ENDF/B-VII nuclear data and were generated using the two-dimensional depletion sequence, TRITON/NEWT, in SCALE 6.1. The libraries contain multiple burnup-dependent cross-sections for seven PWR fuel designs, with enrichments ranging from 1.5 to 6 wt% {sup 235}U. The burnup range has been extended from the 72 GWd/MTU used in previous versions of the libraries to 90 GWd/MTU. Validation of the libraries using radiochemical assay measurements and decay heat measurements for PWR spent fuel showed good agreement between calculated and experimental data. Verification against detailed TRITON simulations for the considered assembly designs showed that depletion calculations performed in ORIGEN-ARP with the pre-generated libraries provide similar results as obtained with direct TRITON depletion, while greatly reducing the computation time. (authors)

  5. A highly heterogeneous 3D PWR core benchmark: deterministic and Monte Carlo method comparison

    NASA Astrophysics Data System (ADS)

    Jaboulay, J.-C.; Damian, F.; Douce, S.; Lopez, F.; Guenaut, C.; Aggery, A.; Poinot-Salanon, C.

    2014-06-01

    Physical analyses of the LWR potential performances with regards to the fuel utilization require an important part of the work dedicated to the validation of the deterministic models used for theses analyses. Advances in both codes and computer technology give the opportunity to perform the validation of these models on complex 3D core configurations closed to the physical situations encountered (both steady-state and transient configurations). In this paper, we used the Monte Carlo Transport code TRIPOLI-4®; to describe a whole 3D large-scale and highly-heterogeneous LWR core. The aim of this study is to validate the deterministic CRONOS2 code to Monte Carlo code TRIPOLI-4®; in a relevant PWR core configuration. As a consequence, a 3D pin by pin model with a consistent number of volumes (4.3 millions) and media (around 23,000) is established to precisely characterize the core at equilibrium cycle, namely using a refined burn-up and moderator density maps. The configuration selected for this analysis is a very heterogeneous PWR high conversion core with fissile (MOX fuel) and fertile zones (depleted uranium). Furthermore, a tight pitch lattice is selcted (to increase conversion of 238U in 239Pu) that leads to harder neutron spectrum compared to standard PWR assembly. In these conditions two main subjects will be discussed: the Monte Carlo variance calculation and the assessment of the diffusion operator with two energy groups for the core calculation.

  6. Chernobyl NPP: Completion of LRW Treatment Plant and LRW Management on Site - 12568

    SciTech Connect

    Fedorov, Denis; Adamovich, Dmitry; Klimenko, I.; Taranenko, L.

    2012-07-01

    Since a beginning of ChNPP operation, and after a tragedy in 1986, a few thousands m3 of LRW have been collected in a storage tanks. In 2004 ChNPP started the new project on creation of LRW treatment plant (LRWTP) financed from EBRD fund. But it was stopped in 2008 because of financial and contract problems. In 2010 SIA RADON jointly with Ukrainian partners has won a tender on completion of LRWTP, in particular I and C system. The purpose of LRTP is to process liquid rad-wastes from SSE 'Chernobyl NPP' site and those liquids stored in the LRWS and SLRWS tanks as well as the would-be wastes after ChNPP Power Units 1, 2 and 3 decommissioning. The LRTP design lifetime - 20 years. Currently, the LRTP is getting ready to perform the following activities: 1. retrieval of waste from tanks stored at ChNPP LWS using waste retrieval system with existing equipment involved; 2. transfer of retrieved waste into LRTP reception tanks with partial use of existing transfer pipelines; 3. laboratory chemical and radiochemical analysis of reception tanks contest to define the full spectrum of characteristics before processing, to acknowledge the necessity of preliminary processing and to select end product recipe; 4. preliminary processing of the waste to meet the requirements for further stages of the process; 5. shrinkage (concentrating) of preliminary processed waste; 6. solidification of preliminary processed waste with concrete to make a solid-state (end product) and load of concrete compound into 200-l drums; 7. curing of end product drums in LRTP curing hall; 8. radiologic monitoring of end product drums and their loading into special overpacks; 9. overpack radiological monitoring; 10. send for disposal (ICSRM Lot 3); The current technical decisions allow to control and return to ChNPP of process media and supporting systems outputs until they satisfy the following quality norms: salt content: < 100 g/l; pH: 1 - 11; anionic surface-active agent: < 25 mg/l; oil dissipated in the

  7. [The main radionuclides and dose formation in fish of the Chernobyl NPP exclusion zone].

    PubMed

    Gudkov, D I; Kaglian, A E; Kireev, S I; Nazarov, A B; Klenus, V G

    2008-01-01

    The results of the researches of spices-specificity, accumulation dynamics and distribution of 90Sr, of 137Cs and of transuranic elements in fish of the Chernobyl NPP exclusion zone are analysed. The data of estimations of absorbed doze rate from incorporated radionuclides for pray fish and predatory species are given. For the fish from the lake of the left-bank floodplain of the Pripyat River the increase of 90Sr specific activity is registered which is presumably connected with the dynamics of the physical-chemical forms of the radionuclide in soils and their wash out in water bodies from the catchment basin. Now about 90% of internal dose rate of fish from closed aquatic ecosystems within the Chernobyl NPP exclusion zone is caused by 90Sr incorporation. PMID:18666579

  8. Land, Cryosphere, and Nighttime Environmental Products from Suomi NPP VIIRS: Overview and Status

    NASA Technical Reports Server (NTRS)

    Roman, Miguel O.; Justice, Chris; Csiszar, Ivan

    2014-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched in October 2011 as part of the Suomi National Polar-orbiting Partnership (S-NPP: http://npp.gsfc.nasa.gov/). VIIRS was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer (AVHRR) and provide observation continuity with NASA's Earth Observing System's (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS). Since the VIIRS first-light images were received in November 2011, NASA and NOAA funded scientists have been working to evaluate the instrument performance and derived products to meet the needs of the NOAA operational users and the NASA science community. NOAA's focus has been on refining a suite of operational products known as Environmental Data Records (EDRs), which were developed according to project specifications under the former National Polar-orbiting Environmental Satellite System (NPOESS). The NASA S-NPP Science Team has focused on evaluating the EDRs for science use, developing and testing additional products to meet science data needs and providing MODIS data product continuity. This paper will present to-date findings of the NASA Science Team's evaluation of the VIIRS Land and Cryosphere EDRs, specifically Surface Reflectance, Land Surface Temperature, Surface Albedo, Vegetation Indices, Surface Type, Active Fires, Snow Cover, Ice Surface Temperature, and Sea Ice Characterization (http://viirsland.gsfc.nasa.gov/index.html). The paper will also discuss new capabilities being developed at NASA's Land Product Evaluation and Test Element (http://landweb.nascom.nasa.gov/NPP_QA/); including downstream data and products derived from the VIIRS Day/Night Band (DNB).

  9. Joint Polar Satellite System (JPSS) System Architecture: Suomi-NPP to the Future

    NASA Astrophysics Data System (ADS)

    Furgerson, J.; Layns, A.; Feeley, J. H.; Griffin, A.; Trumbower, G.

    2014-12-01

    The National Oceanic and Atmospheric Administration (NOAA) is acquiring the next-generation weather and environmental satellite system, named the Joint Polar Satellite System (JPSS). NOAA has overall responsibility for the system including funding and requirements while the National Aeronautics and Space Administration (NASA) serves as the acquisition and development agent. The Suomi National Polar-orbiting Partnership (S-NPP) satellite was launched on 28 October, 2011, and is a pathfinder for JPSS and provides continuity for the NASA Earth Observation System and the NOAA Polar-orbiting Operational Environmental Satellite (POES) system. S-NPP and the follow-on JPSS satellites will operate in the 1330 LTAN orbit. JPSS-1 is scheduled to launch in early 2017. NASA is developing the Common Ground System which will process JPSS data and has the flexibility to process data from other satellites. This poster will provide a top level status update of the program, as well as an overview of the JPSS system architecture. The space segment carries a suite of sensors that collect meteorological, oceanographic, and climatological observations of the earth and atmosphere. The system design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users through a Command, Control, and Communication Segment (C3S). The data processing for S-NPP/JPSS is accomplished through an Interface Data Processing Segment (IDPS)/Field Terminal Segment (FTS) that processes S-NPP/JPSS satellite data to provide environmental data products to U.S. and international partners as well as remote terminal users throughout the world.

  10. SEISMIC RESPONSE PREDICTION OF NUPEC'S FIELD MODEL TESTS OF NPP STRUCTURES WITH ADJACENT BUILDING EFFECT.

    SciTech Connect

    XU,J.COSTANTINO,C.HOFMAYER,C.ALI,S.

    2004-03-04

    As part of a verification test program for seismic analysis computer codes for Nuclear Power Plant (NPP) structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model tests to address the dynamic cross interaction (DCI) effect on the seismic response of NPP structures built in close proximity to each other. The program provided field data to study the methodologies commonly associated with seismic analyses considering the DCI effect. As part of a collaborative program between the United States and Japan on seismic issues related to NPP applications, the U.S. Nuclear Regulatory Commission sponsored a program at Brookhaven National Laboratory (BNL) to perform independent seismic analyses which applied common analysis procedures to predict the building response to recorded earthquake events for the test models with DCI effect. In this study, two large-scale DCI test model configurations were analyzed: (1) twin reactor buildings in close proximity and (2) adjacent reactor and turbine buildings. This paper describes the NUPEC DCI test models, the BNL analysis using the SASSI 2000 program, and comparisons between the BNL analysis results and recorded field responses. To account for large variability in the soil properties, the conventional approach of computing seismic responses with the mean, mean plus and minus one-standard deviation soil profiles is adopted in the BNL analysis and the three sets of analysis results were used in the comparisons with the test data. A discussion is also provided in the paper to address (1) the capability of the analysis methods to capture the DCI effect, and (2) the conservatism of the practice for considering soil variability in seismic response analysis for adjacent NPP structures.

  11. Managing the equipment service life in rendering engineering support to NPP operation

    NASA Astrophysics Data System (ADS)

    Ryasnyy, S. I.

    2015-05-01

    Apart from subjecting metal to nondestructive testing and determining its actual state, which are the traditional methods used for managing the service life of NPP equipment during its operation, other approaches closely linked with rendering engineering support to NPP operation have emerged in recent decades, which, however, have been covered in publications to a lesser extent. Service life management matters occupy the central place in the structure of engineering support measures. Application of the concept of repairing NPP equipment based on assessing its technical state and the risk of its failure makes it possible to achieve significantly smaller costs for maintenance and repairs and produce a larger amount of electricity due to shorter planned outages. Decreasing the occurrence probability of a process-related abnormality through its prediction is a further development of techniques for monitoring the technical state of equipment and systems. The proposed and implemented procedure for predicting the occurrence of process-related deviations from normal NPP operation opens the possibility to record in the online mode the trends in changes of process parameters that are likely to lead to malfunctions in equipment operation and to reduce the probability of power unit unloading when an abnormal technical state of equipment occurs and develops by recording changes in the state at an early stage and taking timely corrective measures. The article presents the structure of interconnections between the objectives and conditions of adjustment and commissioning tests, in which the management of equipment service life (saving and optimizing the service life) occupies the central place. Special attention is paid to differences in resource saving and optimization measures.

  12. Characterization and Performance of the Suomi-NPP VIIRS Solar Diffuser Stability Monitor

    NASA Technical Reports Server (NTRS)

    Fulbright, Jon P.; Ning, Lei; Kwofu, Chiang; Xiaoxiong, Xiong

    2012-01-01

    We describe the on-orbit characterization and performance of the Solar Diffuser Stability Monitor (SDSM) on-board Suomi-NPP/VIIRS. This description includes the observing procedure of each SDSM event, the algorithms used to generate the Solar Diffuser degradation corrective factors, and the results for the mission to date. We will also compare the performance of the VIIRS SDSM and SD to the similar components operating on the MODIS instrument on the EOS Terra and Aqua satellites

  13. NPP VIIRS and Aqua MODIS RSB comparison using observations from simultaneous nadir overpasses (SNO)

    NASA Astrophysics Data System (ADS)

    Wu, Aisheng; Xiong, Xiaoxiong

    2012-09-01

    Suomi NPP (National Polar-orbiting Partnership) satellite (http://npp.gsfc.nasa.gov/viirs.html) began to daily collect global data following its successful launch on October 28, 2011. The Visible Infrared Imaging Radiometer Suite (VIIRS) is a key NPP sensor. Similar to the design of the OLS, SeaWiFS and MODIS instruments, VIIRS has on-board calibration components including a solar diffuser (SD) and a solar diffuser stability monitor (SDSM) for the reflective solar bands (RSB), a V-groove blackbody for the thermal emissive bands (TEB), and a space view (SV) port for background subtraction. Immediately after the VIIRS nadir door's opening on November 21, 2011, anomalously large degradation in the SD response was identified in the near-IR wavelength region, which was unexpected as decreases in the SD reflectance usually occur gradually in the blue (~0.4 μm) wavelength region based on past experience. In this study, we use a well-calibrated Aqua MODIS as reference to track and evaluate VIIRS RSB stability and performance. Reflectances observed by both sensors from simultaneous nadir overpasses (SNO) are used to determine VIIRS to MODIS reflectance ratios for their spectral matching bands. Results of this study provide an immediate post-launch assessment, independent validation of the anomalous degradation observed in SD measurements at near-IR wavelengths and initial analysis of calibration stability and consistency.

  14. An overview of the ENEA activities in the field of coupled codes NPP simulation

    SciTech Connect

    Parisi, C.; Negrenti, E.; Sepielli, M.; Del Nevo, A.

    2012-07-01

    In the framework of the nuclear research activities in the fields of safety, training and education, ENEA (the Italian National Agency for New Technologies, Energy and the Sustainable Development) is in charge of defining and pursuing all the necessary steps for the development of a NPP engineering simulator at the 'Casaccia' Research Center near Rome. A summary of the activities in the field of the nuclear power plants simulation by coupled codes is here presented with the long term strategy for the engineering simulator development. Specifically, results from the participation in international benchmarking activities like the OECD/NEA 'Kalinin-3' benchmark and the 'AER-DYN-002' benchmark, together with simulations of relevant events like the Fukushima accident, are here reported. The ultimate goal of such activities performed using state-of-the-art technology is the re-establishment of top level competencies in the NPP simulation field in order to facilitate the development of Enhanced Engineering Simulators and to upgrade competencies for supporting national energy strategy decisions, the nuclear national safety authority, and the R and D activities on NPP designs. (authors)

  15. Pharmacokinetics of hederacoside C, an active ingredient in AG NPP709, in rats.

    PubMed

    Kim, Ju Myung; Yoon, Ji Na; Jung, Ji Won; Choi, Hye Duck; Shin, Young June; Han, Chang Kyun; Lee, Hye Suk; Kang, Hee Eun

    2013-11-01

    1. Hederacoside C (HDC) is one of the active ingredients in Hedera helix leaf extract (Ivy Ex.) and AG NPP709, a new botanical drug to treat acute respiratory infection and chronic inflammatory bronchitis. However, information regarding its pharmacokinetic properties remains limited. 2. Here, we report the pharmacokinetics of HDC in rats after intravenous administration of HDC (3, 12.5, and 25 mg/kg) and after oral administration of HDC, Ivy Ex., and AG NPP709 (equivalent to 12.5, 25, and 50 mg/kg HDC). 3. Linear pharmacokinetics of HDC were identified upon its intravenous administration at doses of 3-25 mg/kg. Intravenous administration of HDC results in relatively slow clearance (1.46-2.08 mL/min/kg) and a small volume of distribution at steady state (138-222 mL/kg), while oral administration results in a low absolute oral bioavailability (F) of 0.118-0.250%. The extremely low F of HDC may be due to poor absorption of HDC from the gastrointestinal (GI) tract and/or its decomposition therein. 4. The oral pharmacokinetics of HDC did not differ significantly among pure HDC, Ivy Ex., and AG NPP709. PMID:23607546

  16. Principles on Radiological Characterization of the Unit 1 at Ignalina NPP for Decommissioning Purposes

    SciTech Connect

    Poskas, P.; Zujus, R.; Drumstas, G.; Poskas, R.; Simonis, V.

    2008-07-01

    There is only one nuclear power plant in Lithuania - Ignalina NPP (INPP). The INPP operated two similar units with installed capacity of 1500 MW(each). They were commissioned in 12/1983 and 08/1987, and the original design lifetime was projected out to 2010 and 2015 respectively. But the first Unit of Ignalina NPP was shutdown December 31, 2004, and second Unit will be closed down before 2010 taking into consideration substantial long-term financial assistance from the EU, G7 and other states as well as international institutions. Implementation of dismantling activities requires detailed knowledge of the radiological situation at the Unit 1. General Programme of Radiological Survey for Ignalina NPP Unit 1 based on NUREG-1575 was prepared in 2005- 2006 by Consortium led by Lithuanian Energy Institute and approved by Regulatory Bodies. It includes such main steps as historical site assessment, scoping, characterization, remedial actions/decontamination support surveys and final status surveys. General Programme of Radiological Survey defines content and principles of the surveys, and preliminary survey considerations, including identification of the contaminants, establishment of the free release levels, principles on areas classification depending on contamination potential, identification of the final survey units, criteria for selection survey instrumentation, techniques and methods etc. So, in the paper information on these principles and the content of the different stages in General Programme of Radiological Survey is presented. (authors)

  17. Conformity Between LR0 Mock-Ups and Vvers Npp Rpv Neutron Flux Attenuation

    NASA Astrophysics Data System (ADS)

    Belousov, Sergey; Ilieva, Krassimira; Kirilova, Desislava

    2009-08-01

    The conformity of the mock-up results and those for reactor pressure vessel (RPV) of nuclear power plants (NPP) has been evaluated in order to qualify if the mock-ups data could be used for benchmark's purpose only, or/and for simulating of the NPP irradiation conditions. Neutron transport through the vessel has been calculated by the three-dimensional discrete ordinate code TORT with problem oriented multigroup energy neutron cross-section library BGL. Neutron flux/fluence and spectrum shape represented by normalized group neutron fluxes in the multigroup energy structure, for neutrons with energy above 0.5 MeV, have been used for conformity analysis. It has been demonstrated that the relative difference of the attenuation factor as well as the group neutron fluxes did not exceed 10% at all considered positions for VVER-440. For VVER-1000, it has been obtained the same consistency, except for the location behind the RPV. The neutron flux attenuation behind the RPV is 18% higher than the mock-up attenuation. It has been shown that this difference arises from the dissimilarity of the biological shielding. The obtained results have demonstrated that the VVERs' mock-ups are appropriate for simulating the NPP irradiation conditions. The mock-up results for VVER-1000 have to be applied more carefully i.e. taking into account the existing peculiarity of the biological shielding and RPV attenuation azimuthal dependence.

  18. Assessing Forest NPP: BIOME-BGC Predictions versus BEF Derived Estimates

    NASA Astrophysics Data System (ADS)

    Hasenauer, H.; Pietsch, S. A.; Petritsch, R.

    2007-05-01

    Forest productivity has always been a major issue within sustainable forest management. While in the past terrestrial forest inventory data have been the major source for assessing forest productivity, recent developments in ecosystem modeling offer an alternative approach using ecosystem models such as Biome-BGC to estimate Net Primary Production (NPP). In this study we compare two terrestrial driven approaches for assessing NPP: (i) estimates from a species specific adaptation of the biogeochemical ecosystem model BIOME-BGC calibrated for Alpine conditions; and (ii) NPP estimates derived from inventory data using biomass expansion factors (BEF). The forest inventory data come from 624 sample plots across Austria and consist of repeated individual tree observations and include growth as well as soil and humus information. These locations are covered with spruce, beech, oak, pine and larch stands, thus addressing the main Austrian forest types. 144 locations were previously used in a validating effort to produce species-specific parameter estimates of the ecosystem model. The remaining 480 sites are from the Austrian National Forest Soil Survey carried out at the Federal Research and Training Centre for Forests, Natural Hazards and Landscape (BFW). By using diameter at breast height (dbh) and height (h) volume and subsequently biomass of individual trees were calculated, aggregated for the whole forest stand and compared with the model output. Regression analyses were performed for both volume and biomass estimates.

  19. Assessment of core damage frequency owing to possible fires at NPP with RBMK type reactors

    SciTech Connect

    Vinnikov, B.

    2012-07-01

    According to Scientific and Technical Cooperation between the USA and Russia in the field of nuclear engineering the Idaho National Laboratory has transferred to the possession of the National Research Center ' Kurchatov Inst. ' the SAPHIRE software without any fee. With the help of the software Kurchatov Inst. developed a Pilot Living PSA- Model of Leningrad NPP Unit 1. Computations of core damage frequencies were carried out for additional Initiating Events. In the submitted paper such additional Initiating Events are fires in various compartments of the NPP. During the computations of each fire, structure of the PSA - Model was not changed, but Fault Trees for the appropriate systems, which are removed from service during the fire, were changed. It follows from the computations, that for ten fires Core Damaged Frequencies (CDF) are not changed. Other six fires will cause additional core damage. On the basis of the calculated results it is possible to determine a degree of importance of these fires and to establish sequence of performance of fire-prevention measures in various places of the NPP. (authors)

  20. Monitoring NPP VIIRS on-orbit radiometric performance from TOA reflectance time series

    NASA Astrophysics Data System (ADS)

    Wu, A.; Xiong, X.; Cao, C.; Sun, C.

    2013-09-01

    The recently launched (October 28, 2011) Suomi NPP (National Polar-orbiting Partnership) satellite has been operating nominally to daily collect global data. The Visible Infrared Imaging Radiometer Suite (VIIRS) is a key NPP sensor onboard the spacecraft. Similar to the heritage sensor MODIS, VIIRS has on-board calibration components including a solar diffuser (SD) and a solar diffuser stability monitor (SDSM) for the reflective solar bands (RSB), a V-groove blackbody for the thermal emissive bands (TEB), and a space view (SV) port for background. This study examines VIIRS reflective solar bands (RSB) calibration stability and performance using observed top-of-atmosphere (TOA) reflectance time series collected from two approaches. The first is from comparison with a well-calibrated Aqua MODIS and the second is from overpasses over the widely used Liby-4 desert site. The VIIRS and MODIS comparison data is obtained from simultaneous nadir overpasses (SNO) for their spectrally matched bands. The reflectance trends over the Libya-4 site are extracted from 16-day repeatable orbits so each data point has the same viewing geometry relative to the site. The impact due to the band spectral differences between the two instruments is corrected based on MODTRAN5 simulations. Results of this study provide useful information on NPP VIIRS post-launch calibration assessment and preliminary analysis of its calibration stability and consistency for the first 1.5 years.

  1. NPP VIIRS and Aqua MODIS RSB Comparison Using Observations from Simultaneous Nadir Overpasses (SNO)

    NASA Technical Reports Server (NTRS)

    Xiong, X.; Wu, A.

    2012-01-01

    Suomi NPP (National Polar-orbiting Partnership) satellite (http://npp.gsfc.nasa.gov/viirs.html) began to daily collect global data following its successful launch on October 28, 2011. The Visible Infrared Imaging Radiometer Suite (VIIRS) is a key NPP sensor. Similar to the design of the OLS, SeaWiFS and MODIS instruments, VIIRS has on-board calibration components including a solar diffuser (SD) and a solar diffuser stability monitor (SDSM) for the reflective solar bands (RSB), a V-groove blackbody for the thermal emissive bands (TEB), and a space view (SV) port for background subtraction. Immediately after the VIIRS nadir door s opening on November 21, 2011, anomalously large degradation in the SD response was identified in the near-IR wavelength region, which was unexpected as decreases in the SD reflectance usually occur gradually in the blue (0.4 m) wavelength region based on past experience. In this study, we use a well-calibrated Aqua MODIS as reference to track and evaluate VIIRS RSB stability and performance. Reflectances observed by both sensors from simultaneous nadir overpasses (SNO) are used to determine VIIRS to MODIS reflectance ratios for their spectral matching bands. Results of this study provide an immediate post-launch assessment, independent validation of the anomalous degradation observed in SD measurements at near-IR wavelengths and initial analysis of calibration stability and consistency.

  2. Joint Polar Satellite System (JPSS) Common Ground System (CGS) Performance for Suomi NPP

    NASA Astrophysics Data System (ADS)

    Idol, J.; Grant, K. D.; Waas, W.; Austin, J.

    2012-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS will contribute the afternoon orbit component and ground processing system of the restructured National Polar-orbiting Operational Environmental Satellite System (NPOESS). As such, the Joint Polar Satellite System replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by the National Oceanic and Atmospheric Administration and the ground processing component of both Polar-orbiting Operational Environmental Satellites and the Defense Meteorological Satellite Program (DMSP) replacement, previously known as the Defense Weather Satellite System (DWSS), managed by the Department of Defense (DoD). The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS), and consists of a Command, Control, and Communications Segment (C3S) and an Interface Data Processing Segment (IDPS). Both segments are developed by Raytheon Intelligence and Information Systems (IIS). The C3S currently flies the Suomi National Polar Partnership (Suomi NPP) satellite and transfers mission data from Suomi NPP and between the ground facilities. The IDPS processes Suomi NPP satellite data to provide Environmental Data Records (EDRs) to NOAA and DoD processing centers operated by the United States government. When the JPSS-1 satellite is launched in early 2017, the responsibilities of the C3S and the IDPS will be expanded to support both Suomi NPP and JPSS-1. The Suomi NPP launched on October 28, 2011. Launch was followed by a phase of sensor activation, and full volume data traffic is now flowing from the

  3. Suomi Npp and Jpss Pre-Launch Test Data Collection and Archive

    NASA Astrophysics Data System (ADS)

    Denning, M.; Ullman, R.; Guenther, B.; Kilcoyne, H.; Chandler, C.; Adameck, J.

    2012-12-01

    During the development of each Suomi National Polar-orbiting Partnership (Suomi NPP) instrument, significant testing was performed, both in ambient and simulated orbital (thermal-vacuum) conditions, at the instrument factory, and again after integration with the spacecraft. The NPOESS Integrated Program Office (IPO), and later the NASA Joint Polar Satellite System (JPSS) Program Office, defined two primary objectives with respect to capturing instrument and spacecraft test data during these test events. The first objective was to disseminate test data and auxiliary documentation to an often distributed network of scientists to permit timely production of independent assessments of instrument performance, calibration, data quality, and test progress. The second goal was to preserve the data and documentation in a catalogued government archive for the life of the mission, to aid in the resolution of anomalies and to facilitate the comparison of on-orbit instrument operating characteristics to those observed prior to launch. In order to meet these objectives, Suomi NPP pre-launch test data collection, distribution, processing, and archive methods included adaptable support infrastructures to quickly and completely transfer test data and documentation from the instrument and spacecraft factories to sensor scientist teams on-site at the factory and around the country. These methods were unique, effective, and low in cost. These efforts supporting pre-launch instrument calibration permitted timely data quality assessments and technical feedback from contributing organizations within the government, academia, and industry, and were critical in supporting timely sensor development. Second, in parallel to data distribution to the sensor science teams, pre-launch test data were transferred and ingested into the central Suomi NPP calibration and validation (cal/val) system, known as the Government Resource for Algorithm Verification, Independent Testing, and Evaluation

  4. A Study on the Conceptual Design of a 1,500 MWe Passive PWR with Annular Fuel

    SciTech Connect

    Kwi Lim Lee; Soon Heung Chang

    2004-07-01

    In this study, the preliminary conceptual design of a 1500 MWe pressurized water reactor (PWR) with annular fuel has been performed. This design is derived from the AP1000 which is a 1000 MWe PWR with two-loop. However, the present design is a 1500 MWe PWR with three-loop, passive safety features and extensive plant simplifications to enhance the construction, operation, and maintenance. The preliminary design parameters of this reactor have been determined through simple relation to those of AP1000 for reactor, reactor coolant system, and passive safety injection system. Using the MATRA code, we analyze the core designs for two alternatives on fuel assembly types: solid fuel and annular fuel. The performance of reactor cooling systems is evaluated through the accident of the cold leg break in the core makeup tank loop by using MARS2.1 code. This study presents the developmental strategy, preliminary design parameters and safety analysis results. (authors)

  5. PWR Facility Dose Modeling Using MCNP5 and the CADIS/ADVANTG Variance-Reduction Methodology

    SciTech Connect

    Blakeman, Edward D; Peplow, Douglas E.; Wagner, John C; Murphy, Brian D; Mueller, Don

    2007-09-01

    The feasibility of modeling a pressurized-water-reactor (PWR) facility and calculating dose rates at all locations within the containment and adjoining structures using MCNP5 with mesh tallies is presented. Calculations of dose rates resulting from neutron and photon sources from the reactor (operating and shut down for various periods) and the spent fuel pool, as well as for the photon source from the primary coolant loop, were all of interest. Identification of the PWR facility, development of the MCNP-based model and automation of the run process, calculation of the various sources, and development of methods for visually examining mesh tally files and extracting dose rates were all a significant part of the project. Advanced variance reduction, which was required because of the size of the model and the large amount of shielding, was performed via the CADIS/ADVANTG approach. This methodology uses an automatically generated three-dimensional discrete ordinates model to calculate adjoint fluxes from which MCNP weight windows and source bias parameters are generated. Investigative calculations were performed using a simple block model and a simplified full-scale model of the PWR containment, in which the adjoint source was placed in various regions. In general, it was shown that placement of the adjoint source on the periphery of the model provided adequate results for regions reasonably close to the source (e.g., within the containment structure for the reactor source). A modification to the CADIS/ADVANTG methodology was also studied in which a global adjoint source is weighted by the reciprocal of the dose response calculated by an earlier forward discrete ordinates calculation. This method showed improved results over those using the standard CADIS/ADVANTG approach, and its further investigation is recommended for future efforts.

  6. Optimization of burnable poison design for Pu incineration in fully fertile free PWR core

    SciTech Connect

    Fridman, E.; Shwageraus, E.; Galperin, A.

    2006-07-01

    The design challenges of the fertile-free based fuel (FFF) can be addressed by careful and elaborate use of burnable poisons (BP). Practical fully FFF core design for PWR reactor has been reported in the past [1]. However, the burnable poison option used in the design resulted in significant end of cycle reactivity penalty due to incomplete BP depletion. Consequently, excessive Pu loading were required to maintain the target fuel cycle length, which in turn decreased the Pu burning efficiency. A systematic evaluation of commercially available BP materials in all configurations currently used in PWRs is the main objective of this work. The BP materials considered are Boron, Gd, Er, and Hf. The BP geometries were based on Wet Annular Burnable Absorber (WABA), Integral Fuel Burnable Absorber (IFBA), and Homogeneous poison/fuel mixtures. Several most promising combinations of BP designs were selected for the full core 3D simulation. All major core performance parameters for the analyzed cases are very close to those of a standard PWR with conventional UO{sub 2} fuel including possibility of reactivity control, power peaking factors, and cycle length. The MTC of all FFF cores was found at the full power conditions at all times and very close to that of the UO{sub 2} core. The Doppler coefficient of the FFF cores is also negative but somewhat lower in magnitude compared to UO{sub 2} core. The soluble boron worth of the FFF cores was calculated to be lower than that of the UO{sub 2} core by about a factor of two, which still allows the core reactivity control with acceptable soluble boron concentrations. The main conclusion of this work is that judicial application of burnable poisons for fertile free fuel has a potential to produce a core design with performance characteristics close to those of the reference PWR core with conventional UO{sub 2} fuel. (authors)

  7. Impact of radiation embrittlement on integrity of pressure vessel supports for two PWR plants

    SciTech Connect

    Cheverton, R.D.; Pennell, W.E.; Robinson, G.C.; Nanstad, R.K.

    1989-01-01

    Recent data from the HFIR vessel surveillance program indicate a substantial radiation embrittlement rate effect at low irradiation temperatures (/approximately/120/degree/F) for A212-B, A350-LF3, A105-II, and corresponding welds. PWR vessel supports are fabricated of similar materials and are subjected to the same low temperatures and fast neutron fluxes (10/sup 8/ to 10/sup 9/ neutrons/cm/sup 2//center dot/s, E > 1.0 MeV) as those in the HFIR vessel. Thus, the embrittlement rate of these structures may be greater than previously anticipated. A study sponsored by the NRC is under way at ORNL to determine the impact of the rate effect on PWR vessel-support life expectancy. The scope includes the interpretation and application of the HFIR data, a survey of all light-water-reactor vessel support designs, and a structural and fracture-mechanics analysis of the supports for two specific PWR plants of particular interest with regard to a potential for support failure as a result of propagation of flaws. Calculations performed thus far indicate best-estimate critical flaw sizes, corresponding to 32 EFPY, of /approximately/0.2 in. for one plant and /approximately/0.4 in. for the other. These flaw sizes are small enough to be of concern. However, it appears that low-cycle fatigue is not a viable mechanism for creation of flaws of this size, and thus, presumably, such flaws would have to exist at the time of fabrication. 59 refs., 128 figs., 49 tabs.

  8. User's guide for the PWR LOCA analysis capability of the WRAP-EM system

    SciTech Connect

    Beranek, F; Gregory, M V

    1980-02-01

    The Water Reactor Analysis Package (WRAP) has been expanded to provide the capability to analyze loss-of-coolant accidents (LOCAs) in both pressurized water reactors (PWRs) and boiling water reactors (BWRs) by using evaluation models (EMs). The input specifications for modules in the WRAP-EM system are presented in this document along with the JOSHUA input templates. This document, along with the WRAP user's guide, provides a step-by-step procedure for setting up a PWR data base for the WRAP-EM system. 12 refs.

  9. Thermal Response of the 21-PWR Waste Package to a Fire Accident

    SciTech Connect

    F.P. Faucher; H. Marr; M.J. Anderson

    2000-10-03

    The objective of this calculation is to evaluate the thermal response of the 21-PWR WP (pressurized water reactor waste package) to the regulatory fire event. The scope of this calculation is limited to the two-dimensional waste package temperature calculations to support the waste package design. The information provided by the sketches attached to this calculation (Attachment IV) is that of the potential design of the type of waste package considered in this calculation. The procedure AP-3.12Q.Calculations (Reference 1), and the Development Plan (Reference 24) are used to develop this calculation.

  10. CRACK GROWTH RESPONSE OF ALLOY 152 AND 52 WELD METALS IN SIMULATED PWR PRIMARY WATER

    SciTech Connect

    Toloczko, Mychailo B.; Bruemmer, Stephen M.

    2009-12-01

    The crack growth response of alloy 152 and 52 weld metals has been measured in simulated PWR primary water at both high (325-350 C) and low (50 C) temperatures. Tests were performed on samples machined from alloy 152 or 52 mockup welds. Propagation rates under cycle + hold and constant K conditions at high temperatures show stable, but extremely low SCC growth rates. The most significant intergranular cracking occurred during cycling at 50 C, particularly for the alloy 152 weld metal at high stress intensity.

  11. MELCOR analyses of severe accident scenarios in Oconee, a B&W PWR plant

    SciTech Connect

    Madni, I.K.; Nimnual, S.; Foulds, R.

    1993-03-01

    This paper presents the results and insights gained from MELCOR analyses of two severe accident scenarios, a Loss of Coolant Accident (LOCA) and a Station Blackout (TMLB) in Oconee, a Babcock & Wilcox (B&W) designed PWR with a large dry containment, and comparisons with Source Term Code Package (STCP) calculations of the same sequences. Results include predicted timing of key events, thermal-hydraulic response in the reactor coolant system and containment, and environmental releases of fission products. The paper also explores the impact of varying concrete type, vessel failure temperature, and break location on the accident progression, containment pressurization, and environmental releases of radionuclides.

  12. MELCOR analyses of severe accident scenarios in Oconee, a B W PWR plant

    SciTech Connect

    Madni, I.K.; Nimnual, S. ); Foulds, R. )

    1993-01-01

    This paper presents the results and insights gained from MELCOR analyses of two severe accident scenarios, a Loss of Coolant Accident (LOCA) and a Station Blackout (TMLB) in Oconee, a Babcock Wilcox (B W) designed PWR with a large dry containment, and comparisons with Source Term Code Package (STCP) calculations of the same sequences. Results include predicted timing of key events, thermal-hydraulic response in the reactor coolant system and containment, and environmental releases of fission products. The paper also explores the impact of varying concrete type, vessel failure temperature, and break location on the accident progression, containment pressurization, and environmental releases of radionuclides.

  13. SCALE 5.1 Predictions of PWR Spent Nuclear Fuel Isotopic Compositions

    SciTech Connect

    Radulescu, Georgeta; Gauld, Ian C; Ilas, Germina

    2010-03-01

    The purpose of this calculation report is to document the comparison to measurement of the isotopic concentrations for pressurized water reactor (PWR) spent nuclear fuel determined with the Standardized Computer Analysis for Licensing Evaluation (SCALE) 5.1 (Ref. ) epletion calculation method. Specifically, the depletion computer code and the cross-section library being evaluated are the twodimensional (2-D) transport and depletion module, TRITON/NEWT,2, 3 and the 44GROUPNDF5 (Ref. 4) cross-section library, respectively, in the SCALE .1 code system.

  14. Nuclear data uncertainties by the PWR MOX/UO{sub 2} core rod ejection benchmark

    SciTech Connect

    Pasichnyk, I.; Klein, M.; Velkov, K.; Zwermann, W.; Pautz, A.

    2012-07-01

    Rod ejection transient of the OECD/NEA and U.S. NRC PWR MOX/UO{sub 2} core benchmark is considered under the influence of nuclear data uncertainties. Using the GRS uncertainty and sensitivity software package XSUSA the propagation of the uncertainties in nuclear data up to the transient calculations are considered. A statistically representative set of transient calculations is analyzed and both integral as well as local output quantities are compared with the benchmark results of different participants. It is shown that the uncertainties in nuclear data play a crucial role in the interpretation of the results of the simulation. (authors)

  15. Application of LBB to high energy piping systems in operating PWR

    SciTech Connect

    Swamy, S.A.; Bhowmick, D.C.

    1997-04-01

    The amendment to General Design Criterion 4 allows exclusion, from the design basis, of dynamic effects associated with high energy pipe rupture by application of leak-before-break (LBB) technology. This new approach has resulted in substantial financial savings to utilities when applied to the Pressurized Water Reactor (PWR) primary loop piping and auxiliary piping systems made of stainless steel material. To date majority of applications pertain to piping systems in operating plants. Various steps of evaluation associated with the LBB application to an operating plant are described in this paper.

  16. Neutronics and safety characteristics of a 100% MOX fueled PWR using weapons grade plutonium

    SciTech Connect

    Biswas, D.; Rathbun, R.; Lee, Si Young; Rosenthal, P.

    1993-12-31

    Preliminary neutronics and safety studies, pertaining to the feasibility of using 100% weapons grade mixed-oxide (MOX) fuel in an advanced PWR Westinghouse design are presented in this paper. The preliminary results include information on boron concentration, power distribution, reactivity coefficients and xenon and control rode worth for the initial and the equilibrium cycle. Important safety issues related to rod ejection and steam line break accidents and shutdown margin requirements are also discussed. No significant change from the commercial design is needed to denature weapons-grade plutonium under the current safety and licensing criteria.

  17. Development of inspection systems for alloy 600 nozzles of PWR reactor vessel

    SciTech Connect

    Unate, K.; Ideo, M.; Sanagawa, T.; Shirai, T.; Araki, Y.

    1995-08-01

    PWR reactor vessels have alloy 600 nozzles at top and bottom heads. The former are head penetration nozzles for CRDM, and the latter are bottom mounted instrumentation nozzles. The authors have developed inspection systems of two types for each nozzle to confirm the soundness. ECT and UT Techniques are employed for both systems. These systems are controlled remotely and enable to reduce radiation exposure, inspection time and number of inspectors. Based on the functional tests using full scale mockups, the reliabilities and effectiveness of both systems were confirmed.

  18. Importance of thermal nonequilibrium considerations for the simulation of nuclear reactor LOCA transients. [PWR

    SciTech Connect

    Fischer, S.R.; Nelson, R.A.; Sullivan, L.H.

    1980-01-01

    The purpose of this paper is to show the importance of considering thermal nonequilibrium effects in computer simulations of the refill and reflood portions of pressurized water reactor (PWR) loss-of-coolnat accident (LOCA) transients. Although RELAP4 assumes thermodynamic equilibrium between phases, models that account for the nonequilibrium phenomena associated with the mixing of subcooled emergency cooling water with steam and the superheating of vapor in the presence of liquid droplets have recently been incorporated into the code. Code calculated results, both with and without these new models, have been compared with experimental test data to assess the importance of including thermal nonequilibrium phenomena in computer code simulations.

  19. Secondary Startup Neutron Sources as a Source of Tritium in a Pressurized Water Reactor (PWR) Reactor Coolant System (RCS)

    SciTech Connect

    Shaver, Mark W.; Lanning, Donald D.

    2010-02-01

    The hypothesis of this paper is that the Zircaloy clad fuel source is minimal and that secondary startup neutron sources are the significant contributors of the tritium in the RCS that was previously assigned to release from fuel. Currently there are large uncertainties in the attribution of tritium in a Pressurized Water Reactor (PWR) Reactor Coolant System (RCS). The measured amount of tritium in the coolant cannot be separated out empirically into its individual sources. Therefore, to quantify individual contributors, all sources of tritium in the RCS of a PWR must be understood theoretically and verified by the sum of the individual components equaling the measured values.

  20. Neutron fluence vessel assessment in the 1300 MWe NPP French fleet: the FLUOLE program in EOLE

    SciTech Connect

    Blaise, P.; Thiollay, N.; Fougeras, P.; Destouches, C.; Beretz, D.; Pont, T.; Garnier, D.

    2006-07-01

    The Vessel Neutron fluence assessment is a key parameter for vessel embrittlement determination and plant lifetime estimation To validate this parameters, the CEA and its Industrial Partner EdF have decided to launch a devoted experimental program in the EOLE facility of the Cadarache Research Centre The aim of this proposed FLUOLE experimental program (acronym of Fluence in EOLE) is to provide the most accurate neutron propagation measurements in representative PWR neutron spectrum material and geometry in order to enable a reduction of uncertainties on calculated vessel fluence with Monte-Carlo codes such as MCNP or TRIPOLI. (authors)

  1. Climate change impacts on net primary production (NPP) and export production (EP) regulated by increasing stratification and phytoplankton community structure in CMIP5 models

    NASA Astrophysics Data System (ADS)

    Fu, W.; Randerson, J.; Moore, J. K.

    2015-08-01

    We examine climate change impacts on net primary production (NPP) and export production (sinking particulate flux; EP) with simulations from nine Earth System Models (ESMs) performed in the framework of the fifth Coupled Model Inter-comparison Project (CMIP5). Global NPP and EP are reduced considerably by the end of the century for the intense warming scenario of Representative Concentration Pathway (RCP) 8.5. Relative to the 1990s, global NPP in the 2090s is reduced by 2.3-16 % and EP by 7-18 %. The models with the largest increases in stratification (and largest relative reductions in NPP and EP) also show the largest positive biases in stratification for the contemporary period, suggesting some potential overestimation of climate impacts on NPP and EP. All of the CMIP5 models show an increase in stratification in response to surface ocean warming and freshening that is accompanied by decreases in NPP, EP, and surface macronutrient concentrations. There is considerable variability across models in the absolute magnitude of these fluxes, surface nutrient concentrations, and their perturbations by climate change, indicating large model uncertainties. The negative response of NPP and EP to stratification increases reflects a bottom-up control, as nutrient flux to the euphotic zone declines. Models with dynamic phytoplankton community structure show larger declines in EP than in NPP. This is driven by phytoplankton community composition shifts, with a reduced percentage of NPP by large phytoplankton under RCP 8.5, as smaller phytoplankton are favored under the increasing nutrient stress. Thus, projections of the NPP response to climate change in the CMIP5 models are critically dependent on the simulated phytoplankton community structure, the efficiency of the biological pump, and the resulting (highly variable) levels of regenerated production. Community composition is represented relatively simply in the CMIP5 models, and should be expanded to better capture the

  2. The impact of radiolytic yield on the calculated ECP in PWR primary coolant circuits

    NASA Astrophysics Data System (ADS)

    Urquidi-Macdonald, Mirna; Pitt, Jonathan; Macdonald, Digby D.

    2007-05-01

    A code, PWR-ECP, comprising chemistry, radiolysis, and mixed potential models has been developed to calculate radiolytic species concentrations and the corrosion potential of structural components at closely spaced points around the primary coolant circuits of pressurized water reactors (PWRs). The pH( T) of the coolant is calculated at each point of the primary-loop using a chemistry model for the B(OH) 3 + LiOH system. Although the chemistry/radiolysis/mixed potential code has the ability to calculate the transient reactor response, only the reactor steady state condition (normal operation) is discussed in this paper. The radiolysis model is a modified version of the code previously developed by Macdonald and coworkers to model the radiochemistry and corrosion properties of boiling water reactor primary coolant circuits. In the present work, the PWR-ECP code is used to explore the sensitivity of the calculated electrochemical corrosion potential (ECP) to the set of radiolytic yield data adopted; in this case, one set had been developed from ambient temperature experiments and another set reported elevated temperatures data. The calculations show that the calculated ECP is sensitive to the adopted values for the radiolytic yields.

  3. Survey of the power ramp performance testing of KWU'S PWR UO 2, fuel

    NASA Astrophysics Data System (ADS)

    Ga¨rtner, M.; Fischer, G.

    1987-06-01

    To determine the power ramp performance of KWU's PWR UO 2 fuel, 134 fuel rodlets with burnups of up to 46 GWd/ t (U) and several fuel assemblies with 19 to 30 GWd/t (U) burnup were ramped in power in the research reactors HFR Petten/The Netherlands and R2 Studsvik/Sweden and in the power plants KWO and KWB-A/Germany, respectively. The power ramp tests demonstrate decreasing resistance of the PWR fuel rods to PCI (pellet-to-clad interaction) up to fuel burnups of 35 GWd/t (U) and a reversal effect at higher burnups. The fuel rods can be operated free of defects at fast power transients to linear heat generation rates of up to 400 W/cm, at least.Power levels of up to 490 W/cm can be reached without defects by reducing the ramp rate. After reshuffling according to an out-in scheme, 1-cycle fuel assemblies may return to rod powers of up to 480 W/cm with a power increase rate of up to 10 W/(cm min) without fuel rod damage. Set points basing on these test results and incorporated into the power distribution control and power density limitation system of KWU's advanced power plants guarantee safe plant operation under normal and load follow operating conditions.

  4. Experiment data report for LOFT anticipated transient-without-scram Experiment L9-3. [PWR

    SciTech Connect

    Bayless, P.D.; Divine, J.M.

    1982-05-01

    Selected pertinent and uninterpreted data from the third anticipated transient with multiple failures experiment (Experiment L9-3) conducted in the Loss-of-Fluid Test (LOFT) facility are presented. The LOFT facility is a 50-MW(t) pressurized water reactor (PWR) system with instruments that measure and provide data on the system thermal-hydraulic and nuclear conditions. The operation of the LOFT system is typical of large (approx. 1000 MW(e)), commercial PWR operations. Experiment L9-3 simulated a loss-of-feedwater anticipated transient without scram. The loss-of-feedwater accident led to an increase in the primary coolant system temperature and pressure. Both the experiment power-operated relief valve (PORV) and safety relief valve opened and were able to limit and control the pressure transient. The plant was then recovered with the control rods still withdrawn by injecting 7200-ppM borated water, manually cycling the PORV and feeding and bleeding the steam generator.

  5. Code System for PWR & BWR Multicompartment Containment Analysis, Versions MOD5

    Energy Science and Technology Software Center (ESTSC)

    1999-06-02

    CONTEMPT4/MOD6 describes the response of multicompartment containment systems subjected to postulated loss-of-coolant accident (LOCA) conditions. The program can accommodate both pressurized water reactor (PWR) and boiling water reactor (BWR) containment systems. Also, both design basis accident (DBA) and degraded core type LOCA conditions can be analyzed. The program calculates the time variation of compartment pressures, temperatures, and mass and energy inventories due to inter-compartment mass and energy exchange taking into account user-supplied descriptions of compartments,more » inter-compartment junction flow areas, LOCA source terms, and user-selected problem features. Analytical models available to describe containment systems include models for containment fans and pumps, cooling sprays, heat conducting structures, sump drains, PWR ice condensers, and BWR pressure suppression systems. CONTEMPT4/MOD6 also provides analytical models for hydrogen and carbon monoxide combustion within compartments and energy transfer due to gas radiation to accommodate degraded core type accidents.« less

  6. Validation of the new code package APOLLO2.8 for accurate PWR neutronics calculations

    SciTech Connect

    Santamarina, A.; Bernard, D.; Blaise, P.; Leconte, P.; Palau, J. M.; Roque, B.; Vaglio, C.; Vidal, J. F.

    2013-07-01

    This paper summarizes the Qualification work performed to demonstrate the accuracy of the new APOLLO2.S/SHEM-MOC package based on JEFF3.1.1 nuclear data file for the prediction of PWR neutronics parameters. This experimental validation is based on PWR mock-up critical experiments performed in the EOLE/MINERVE zero-power reactors and on P.I. Es on spent fuel assemblies from the French PWRs. The Calculation-Experiment comparison for the main design parameters is presented: reactivity of UOX and MOX lattices, depletion calculation and fuel inventory, reactivity loss with burnup, pin-by-pin power maps, Doppler coefficient, Moderator Temperature Coefficient, Void coefficient, UO{sub 2}-Gd{sub 2}O{sub 3} poisoning worth, Efficiency of Ag-In-Cd and B4C control rods, Reflector Saving for both standard 2-cm baffle and GEN3 advanced thick SS reflector. From this qualification process, calculation biases and associated uncertainties are derived. This code package APOLLO2.8 is already implemented in the ARCADIA new AREVA calculation chain for core physics and is currently under implementation in the future neutronics package of the French utility Electricite de France. (authors)

  7. Development of a new lattice physics code robin for PWR application

    SciTech Connect

    Zhang, S.; Chen, G.

    2013-07-01

    This paper presents a description of methodologies and preliminary verification results of a new lattice physics code ROBIN, being developed for PWR application at Shanghai NuStar Nuclear Power Technology Co., Ltd. The methods used in ROBIN to fulfill various tasks of lattice physics analysis are an integration of historical methods and new methods that came into being very recently. Not only these methods like equivalence theory for resonance treatment and method of characteristics for neutron transport calculation are adopted, as they are applied in many of today's production-level LWR lattice codes, but also very useful new methods like the enhanced neutron current method for Dancoff correction in large and complicated geometry and the log linear rate constant power depletion method for Gd-bearing fuel are implemented in the code. A small sample of verification results are provided to illustrate the type of accuracy achievable using ROBIN. It is demonstrated that ROBIN is capable of satisfying most of the needs for PWR lattice analysis and has the potential to become a production quality code in the future. (authors)

  8. Bi-content Gadolinia as Burnable Absorber in PWR to Improve the Reactor Core Behaviour

    SciTech Connect

    Zheng, S.

    2007-07-01

    The gadolinia product is one of the standard burnable absorbers used in the PWR long and low leakage fuel cycle in order to control the radial power distribution and to hold down the initial core reactivity. This product presents a large number of advantages such as the high efficiency with only a small number of gadolinia-bearing rods, the easy adjustment between the number and the content of the gadolinia-bearing rods according to the cycle length need and the initial reactivity hold-down, no increasing of boron concentration versus cycle depletion, no additional increasing of internal pressure in poisoned rods, very low additional manufacture cost. On the other hand, some unfavourable phenomena are also observed during the utilization of the gadolinia: amplification of the asymmetrical power distribution and more negative axial offset. Based on the correlation between the gadolinia burnout and its content, the use of gadolinia bi-content will improve the parameters indicated here above. The gadolinia bi-content have been used in BWR for more than 20 years. In this paper, the comparison of the main reactor core physical parameters in PWR, calculated with the AREVA NP standard neutronic code package SCIENCE, is made by using the mono- and bi-content of the gadolinia products in the same fuel assembly. The results show that the asymmetrical axial and azimuthal power distribution can be improved in the case of the bi-content gadolinia product. (authors)

  9. Analysis of loss of off-site power with a PWR at shutdown

    SciTech Connect

    Chu, T.L.; Yoon, W.H.; Fitzpatrick, R.G.

    1987-01-01

    In many probabilistic risk assessments (PRAs), loss of offsite power (LOOP) when a nuclear power plant is operating was found to be a significant contributor to core damage. The purpose of this study is to provide an analysis of a LOOP event that occurs while a pressurized water reactor (PWR) is shut down. The importance of such an analysis was recognized as part of a study to evaluate the core damage frequency due to a loss of decay heat removal (DHR) capability during an outage. When a PWR is in a shutdown condition, there are relatively few technical specification requirements on the operability of safety systems. In fact, some safety systems are intentionally disabled, i.e., the safety injection system and nonoperating charging pumps. Another problem when the reactor is shut down is that the reactor coolant system (RCS) may be partially drained and the steam generators may be unavailable. To determine the time available for operator actions, given that a LOOP occurs during shutdown and the DHR capability is lost, a simple thermal model has been developed. Similar calculations have been performed for other phases of refueling and maintenance outages. A total core damage frequency due to LOOP while the plant is in shutdown has been calculated to be 5.9 x 10/sup -6//yr. This is approximately twice the core damage frequency calculated for LOOP when the plant is at power.

  10. Application of the MELCOR code to design basis PWR large dry containment analysis.

    SciTech Connect

    Phillips, Jesse; Notafrancesco, Allen; Tills, Jack Lee

    2009-05-01

    The MELCOR computer code has been developed by Sandia National Laboratories under USNRC sponsorship to provide capability for independently auditing analyses submitted by reactor manufactures and utilities. MELCOR is a fully integrated code (encompassing the reactor coolant system and the containment building) that models the progression of postulated accidents in light water reactor power plants. To assess the adequacy of containment thermal-hydraulic modeling incorporated in the MELCOR code for application to PWR large dry containments, several selected demonstration designs were analyzed. This report documents MELCOR code demonstration calculations performed for postulated design basis accident (DBA) analysis (LOCA and MSLB) inside containment, which are compared to other code results. The key processes when analyzing the containment loads inside PWR large dry containments are (1) expansion and transport of high mass/energy releases, (2) heat and mass transfer to structural passive heat sinks, and (3) containment pressure reduction due to engineered safety features. A code-to-code benchmarking for DBA events showed that MELCOR predictions of maximum containment loads were equivalent to similar predictions using a qualified containment code known as CONTAIN. This equivalency was found to apply for both single- and multi-cell containment models.

  11. Regeneratively Cooled Liquid Oxygen/Methane Technology Development Between NASA MSFC and PWR

    NASA Technical Reports Server (NTRS)

    Robinson, Joel W.; Greene, Christopher B.; Stout, Jeffrey B.

    2012-01-01

    The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LOX)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon exploration studies. The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. NASA-Marshall Space Flight Center (MSFC) in concert with industry partner Pratt & Whitney Rocketdyne (PWR) utilized a Space Act Agreement to test an oxygen/methane engine system in the Summer of 2010. PWR provided a 5,500 lbf (24,465 N) LOX/LCH4 regenerative cycle engine to demonstrate advanced thrust chamber assembly hardware and to evaluate the performance characteristics of the system. The chamber designs offered alternatives to traditional regenerative engine designs with improvements in cost and/or performance. MSFC provided the test stand, consumables and test personnel. The hot fire testing explored the effective cooling of one of the thrust chamber designs along with determining the combustion efficiency with variations of pressure and mixture ratio. The paper will summarize the status of these efforts.

  12. Recommendations for Addressing Axial Burnup in the PWR Burnup Credit Analyses

    SciTech Connect

    Wagner, J.C.

    2002-10-23

    This report presents studies performed to support the development of a technically justifiable approach for addressing the axial-burnup distribution in pressurized-water reactor (PWR) burnup-credit criticality safety analyses. The effect of the axial-burnup distribution on reactivity and proposed approaches for addressing the axial-burnup distribution are briefly reviewed. A publicly available database of profiles is examined in detail to identify profiles that maximize the neutron multiplication factor, k{sub eff}, assess its adequacy for PWR burnup credit analyses, and investigate the existence of trends with fuel type and/or reactor operations. A statistical evaluation of the k{sub eff} values associated with the profiles in the axial-burnup-profile database was performed, and the most reactive (bounding) profiles were identified as statistical outliers. The impact of these bounding profiles on k{sub eff} is quantified for a high-density burnup credit cask. Analyses are also presented to quantify the potential reactivity consequence of loading assemblies with axial-burnup profiles that are not bounded by the database. The report concludes with a discussion on the issues for consideration and recommendations for addressing axial burnup in criticality safety analyses using burnup credit for dry cask storage and transportation.

  13. Patterns of NPP, GPP, respiration, and NEP during boreal forest succession

    USGS Publications Warehouse

    Goulden, M.L.; Mcmillan, A.M.S.; Winston, G.C.; Rocha, A.V.; Manies, K.L.; Harden, J.W.; Bond-Lamberty, B. P.

    2011-01-01

    We combined year-round eddy covariance with biometry and biomass harvests along a chronosequence of boreal forest stands that were 1, 6, 15, 23, 40, 74, and 154 years old to understand how ecosystem production and carbon stocks change during recovery from stand-replacing crown fire. Live biomass (Clive) was low in the 1 and 6 year old stands, and increased following a logistic pattern to high levels in the 74 and 154year old stands. Carbon stocks in the forest floor (Cforest floor) and coarse woody debris (CCWD) were comparatively high in the 1year old stand, reduced in the 6 through 40year old stands, and highest in the 74 and 154year old stands. Total net primary production (TNPP) was reduced in the 1 and 6year old stands, highest in the 23 through 74year old stands and somewhat reduced in the 154year old stand. The NPP decline at the 154year old stand was related to increased autotrophic respiration rather than decreased gross primary production (GPP). Net ecosystem production (NEP), calculated by integrated eddy covariance, indicated the 1 and 6 year old stands were losing carbon, the 15year old stand was gaining a small amount of carbon, the 23 and 74year old stands were gaining considerable carbon, and the 40 and 154year old stands were gaining modest amounts of carbon. The recovery from fire was rapid; a linear fit through the NEP observations at the 6 and 15year old stands indicated the transition from carbon source to sink occurred within 11-12 years. The NEP decline at the 154year old stand appears related to increased losses from Clive by tree mortality and possibly from Cforest floor by decomposition. Our findings support the idea that NPP, carbon production efficiency (NPP/GPP), NEP, and carbon storage efficiency (NEP/TNPP) all decrease in old boreal stands. ?? 2010 Blackwell Publishing Ltd.

  14. Lunar BRDF Correction of Suomi-NPP VIIRS Day/Night Band Time Series Product

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Roman, M. O.; Kalb, V.; Stokes, E.; Miller, S. D.

    2015-12-01

    Since the first-light images from the Suomi-NPP VIIRS low-light visible Day/Night Band (DNB) sensor were received in November 2011, the NASA Suomi-NPP Land Science Investigator Processing System (SIPS) has focused on evaluating this new capability for quantitative science applications, as well as developing and testing refined algorithms to meet operational and Land science research needs. While many promising DNB applications have been developed since the Suomi-NPP launch, most studies to-date have been limited by the traditional qualitative image display and spatial-temporal aggregated statistical analysis methods inherent in current heritage algorithms. This has resulted in strong interest for a new generation of science-quality products that can be used to monitor both the magnitude and signature of nighttime phenomena and anthropogenic sources of light emissions. In one particular case study, Román and Stokes (2015) demonstrated that tracking daily dynamic DNB radiances can provide valuable information about the character of the human activities and behaviors that influence energy, consumption, and vulnerability. Here we develop and evaluate a new suite of DNB science-quality algorithms that can exclude a primary source of background noise: i.e., the Lunar BRDF (Bidirectional Reflectance Distribution Function) effect. Every day, the operational NASA Land SIPS DNB algorithm makes use of 16 days worth of DNB-derived surface reflectances (SR) (based on the heritage MODIS SR algorithm) and a semiempirical kernel-driven bidirectional reflectance model to determine a global set of parameters describing the BRDF of the land surface. The nighttime period of interest is heavily weighted as a function of observation coverage. These gridded parameters, combined with Miller and Turner's [2009] top-of-atmosphere spectral irradiance model, are then used to determine the DNB's lunar radiance contribution at any point in time and under specific illumination conditions.

  15. An Algorithm For Climate-Quality Atmospheric Profiling Continuity From EOS Aqua To Suomi-NPP

    NASA Astrophysics Data System (ADS)

    Moncet, J. L.

    2015-12-01

    We will present results from an algorithm that is being developed to produce climate-quality atmospheric profiling earth system data records (ESDRs) for application to hyperspectral sounding instrument data from Suomi-NPP, EOS Aqua, and other spacecraft. The current focus is on data from the S-NPP Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments as well as the Atmospheric InfraRed Sounder (AIRS) on EOS Aqua. The algorithm development at Atmospheric and Environmental Research (AER) has common heritage with the optimal estimation (OE) algorithm operationally processing S-NPP data in the Interface Data Processing Segment (IDPS), but the ESDR algorithm has a flexible, modular software structure to support experimentation and collaboration and has several features adapted to the climate orientation of ESDRs. Data record continuity benefits from the fact that the same algorithm can be applied to different sensors, simply by providing suitable configuration and data files. The radiative transfer component uses an enhanced version of optimal spectral sampling (OSS) with updated spectroscopy, treatment of emission that is not in local thermodynamic equilibrium (non-LTE), efficiency gains with "global" optimal sampling over all channels, and support for channel selection. The algorithm is designed for adaptive treatment of clouds, with capability to apply "cloud clearing" or simultaneous cloud parameter retrieval, depending on conditions. We will present retrieval results demonstrating the impact of a new capability to perform the retrievals on sigma or hybrid vertical grid (as opposed to a fixed pressure grid), which particularly affects profile accuracy over land with variable terrain height and with sharp vertical structure near the surface. In addition, we will show impacts of alternative treatments of regularization of the inversion. While OE algorithms typically implement regularization by using background estimates from

  16. MetEd Resources for Embracing Advances with S-NPP and JPSS

    NASA Astrophysics Data System (ADS)

    Abshire, W. E.; Dills, P. N.; Weingroff, M.

    2014-12-01

    The COMET® Program (www.comet.ucar.edu), a part of the UCAR Community Programs (UCP) at UCAR, receives funding from NOAA NESDIS as well as EUMETSAT and the Meteorological Service of Canada to support education and training in satellite meteorology. For many years COMET's satellite education programs have focused on developing self-paced online educational materials that highlight the capabilities and applications of current and next-generation operational geostationary and polar-orbiting satellites and their relevance to operational forecasters and other user communities. By partnering with experts from the Naval Research Laboratory, NOAA-NESDIS and its Cooperative Institutes, Meteorological Service of Canada, EUMETSAT, and other user communities, COMET stimulates greater use of current and future satellite observations and products. This presentation provides a tour of COMET's satellite training and education offerings that are directly applicable to data and products from the S-NPP and JPSS satellite series. A recommended set of lessons for users who wish to learn more will be highlighted, including excerpts from the newest materials on the Suomi NPP VIIRS imager and its applications, as well as advances in nighttime visible observation with the VIIRS Day-Night Band. We'll show how the lessons introduce users to the advances these systems bring to forecasting, numerical weather prediction, and environmental monitoring. Over 90 satellite-focused, self-paced, online materials are freely available on the of the MetEd Web site (http://www.meted.ucar.edu) via the "Education & Training", "Satellite" topic area. Quite a few polar-orbiting-related lessons are available in both English, Spanish, and French. Additionally, S-NPP and JPSS relevant information can also be found on the the Environmental Satellite Resource Center (ESRC) Web site (www.meted.ucar.edu/esrc) that is maintained by COMET. The ESRC is a searchable, database-driven Web site that provides access to

  17. COMET Program Training Offerings to Support S-NPP and JPSS Utilization

    NASA Astrophysics Data System (ADS)

    Abshire, W. E.; Dills, P. N.; Weingroff, M.

    2015-12-01

    Are you up to speed on how to exploit new S-NPP capabilities and products? If not, don't worry, because UCAR's COMET program has self-paced online educational materials that highlight the capabilities and applications of current and next-generation operational polar-orbiting and geostationary satellites. The COMET® Program (www.comet.ucar.edu) has long received funding from NOAA NESDIS as well as EUMETSAT and the Meteorological Service of Canada to support education and training in satellite meteorology. By partnering with experts from NOAA-NESDIS and its Cooperative Institutes, Meteorological Service of Canada, EUMETSAT, the Naval Research Laboratory and others, COMET's self-paced training stimulates greater use of current and future satellite observations and products. Right now, over 70 satellite-focused, self-paced, online materials are freely available in English via the MetEd Web site at http://meted.ucar.edu/topics/satellite. Additionally, quite a few lessons are also available in Spanish and French making training more easily accessible to an international audience. This presentation will focus on COMET's latest satellite training and education offerings that are directly applicable to data and products from the S-NPP and JPSS satellite series. A recommended set of lessons for users who wish to learn more will be highlighted, including excerpts from the newest materials on the Suomi NPP VIIRS imager and its applications, as well as advances in nighttime visible observation with the VIIRS Day-Night Band. We'll show how the lessons introduce users to the advances these systems bring to forecasting, numerical weather prediction, and environmental monitoring. Finally, new relevant training initiatives will also be presented.

  18. OVERVIEW ON BNL ASSESSMENT OF SEISMIC ANALYSIS METHODS FOR DEEPLY EMBEDDED NPP STRUCTURES.

    SciTech Connect

    XU,J.; COSTANTINO, C.; HOFMAYER, C.; GRAVES, H.

    2007-04-01

    A study was performed by Brookhaven National Laboratory (BNL) under the sponsorship of the U. S. Nuclear Regulatory Commission (USNRC), to determine the applicability of established soil-structure interaction analysis methods and computer programs to deeply embedded and/or buried (DEB) nuclear power plant (NPP) structures. This paper provides an overview of the BNL study including a description and discussions of analyses performed to assess relative performance of various SSI analysis methods typically applied to NPP structures, as well as the importance of interface modeling for DEB structures. There are four main elements contained in the BNL study: (1) Review and evaluation of existing seismic design practice, (2) Assessment of simplified vs. detailed methods for SSI in-structure response spectrum analysis of DEB structures, (3) Assessment of methods for computing seismic induced earth pressures on DEB structures, and (4) Development of the criteria for benchmark problems which could be used for validating computer programs for computing seismic responses of DEB NPP structures. The BNL study concluded that the equivalent linear SSI methods, including both simplified and detailed approaches, can be extended to DEB structures and produce acceptable SSI response calculations, provided that the SSI response induced by the ground motion is very much within the linear regime or the non-linear effect is not anticipated to control the SSI response parameters. The BNL study also revealed that the response calculation is sensitive to the modeling assumptions made for the soil/structure interface and application of a particular material model for the soil.

  19. Digital safety I and C system in the Paks NPP (Hungary))

    SciTech Connect

    Eiler, J.

    2006-07-01

    The entire replacement of the original, Russian safety I and C system in the Paks NPP concluded successfully in 2003. The new, digital system was selected after a very thorough tendering process and installation was performed within the time-frame of normal refueling outages. The new system has shown very high reliability and flexibility in the past years. Several other nuclear power plants have initiated / completed the same replacement using the same type of equipment. This paper provides a summary on selected technical and organizational issues, as well as the main lessons learned in this very comprehensive and wide-scale project. (authors)

  20. Application of the SASSI soil structure interaction method to CANDU 6 NPP seismic analysis

    SciTech Connect

    Ricciuti, R.A.; Elgohary, M.; Usmani, S.A.

    1996-12-01

    The standard CANDU 6 NPP has been conservatively qualified for a Design Basis Earthquake (DBE) peak horizontal ground acceleration of 0.2 g. Currently there are potential opportunities for siting the CANDU 6 at higher seismicity sites. In order to be able to extend the use of a standardized design for sites with higher seismicity than the standard plant, various design options, including the use of the SASSI Soil Structure Interaction (SSI) analysis method, are being evaluated. This paper presents the results of a study to assess the potential benefits from utilization of the SASSI computer program and the use of more realistic damping ratios for the structures.

  1. Maximim Accelerations On The Fuel Assemblies Of a 21-PWR Waste Package During End Impacts 

    SciTech Connect

    V. DeLa Brosse

    2003-03-27

    The objective of this calculation is to determine the acceleration of the fuel assemblies contained in a 21-Pressurized Water Reactor (PWR) spent nuclear fuel waste package impacting an unyielding surface. A range of initial velocities of the waste package is studied. The scope of this calculation is limited to estimating the acceleration of the fuel assemblies during the impact.

  2. Maximim Accelerations On The Fuel Assemblies Of a 21-PWR Waste Package During End Impacts 

    SciTech Connect

    T. Schmitt

    2005-08-17

    The objective of this calculation is to determine the acceleration of the fuel assemblies contained in a 21-Pressurized Water Reactor (PWR) spent nuclear fuel waste package impacting an unyielding surface. A range of initial velocities of the waste package is studied. The scope of this calculation is limited to estimating the acceleration of the fuel assemblies during the impact.

  3. Proceedings: 1984 Workshop on Secondary-Side Stress Corrosion Cracking and Intergranular Corrosion of PWR Steam Generator Tubing

    SciTech Connect

    1986-03-01

    During 1984, research investigating intergranular corrosion and stress corrosion cracking in PWR steam generators provided data to formulate a corrosion-product transport theory. In addition, the research showed that changing the pH of liquids in generator crevices will retard and sometimes arrest the corrosion process.

  4. End-of-life destructive examinations of Zircaloy maximum depletion blanket fuel plates from the Shippingport PWR Core 2

    SciTech Connect

    Clayton, J.C.; Kammenzind, B.F.; Senio, P.; Sherman, J.

    1993-10-01

    Destructive examinations were performed on four Shippingport PWR Core 2 maximum fluence and depletion blanket plates for surface integrity, corrosion oxide thickness, and hydrogen absorption of the Zircaloy-4 cladding. The Shippingport PWR Core 2 operated for 23,360 effective full power hours (EFPH) (62,235 hot hours) at an average coolant temperature of 536{degrees}F (280{degrees}C) and a peak neutron flux of 0.6{times}10{sup 14}n/cm{sup 2}/s. The end-of-life examination program included measurements on three PWR-2 beta-quenched blanket fuel plates and one alpha-annealed blanket end plate. The examinations consisted of optical and scanning electron microscopy (SEM) inspections, direct metallographic oxide thickness measurements, and hydrogen extraction analyses on a joined element pair from the peak fluence (132{times}10{sup 20} n/cm{sup 2}), maximum depletion (13.5{times}10{sup 20} fissions/cc)PWR-2 blanket cluster.

  5. Role of research reactors in training of NPP personnel with special focus on training reactor VR-1

    SciTech Connect

    Sklenka, L.; Rataj, J.; Frybort, J.; Huml, O.

    2012-07-01

    Research reactors play an important role in providing key personnel of nuclear power plants a hands-on experience from operation and experiments at nuclear facilities. Training of NPP (Nuclear Power Plant) staff is usually deeply theoretical with an extensive utilisation of simulators and computer visualisation. But a direct sensing of the reactor response to various actions can only improve the personnel awareness of important aspects of reactor operation. Training Reactor VR-1 and its utilization for training of NPP operators and other professionals from Czech Republic and Slovakia is described. Typical experimental exercises and good practices in organization of a training program are demonstrated. (authors)

  6. Calculation of releases of radioactive materials in gaseous and liquid effluents from pressurized water reactors (PWR-GALE Code). Revision 1

    SciTech Connect

    Chandrasekaran, T.; Lee, J.Y.; Willis, C.A.

    1985-04-01

    This report revises the original issuance of NUREG-0017, ''Calculation of Releases of Radioactive Materials in Gaseous and Liquid Effluents from Pressurized Water Reactors (PWR-GALE-Code)'' (April 1976), to incorporate more recent operating data now available as well as the results of a number of in-plant measurement programs at operating pressurized water reactors. The PWR-GALE Code is a computerized mathematical model for calculating the releases of radioactive material in gaseous and liquid effluents (i.e., the gaseous and liquid source terms). The US Nuclear Regulatory Commission uses the PWR-GALE Code to determine conformance with the requirements of Appendix I to 10 CFR Part 50.

  7. Land and Cryosphere Products from Suomi NPP VIIRS: Overview and Status

    NASA Technical Reports Server (NTRS)

    Justice, Christopher O.; Roman, Miguel O.; Csiszar, Ivan; Vermote, Eric F.; Wolfe, Robert E.; Hook, Simon J.; Friedl, Mark; Wang, Zhuosen; Schaaf, Crystal B.; Miura, Tomoaki; Tschudi, Mark; Riggs, George; Hall, Dorothy K.; Lyapustin, Alexei I.; Devadiga, Sadashiva; Davidson, Carol; Masuoka, Edward

    2013-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched in October 2011 as part of the Suomi National Polar-Orbiting Partnership (S-NPP). The VIIRS instrument was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer and provide observation continuity with NASA's Earth Observing System's Moderate Resolution Imaging Spectroradiometer (MODIS). Since the VIIRS first-light images were received in November 2011, NASA- and NOAA-funded scientists have been working to evaluate the instrument performance and generate land and cryosphere products to meet the needs of the NOAA operational users and the NASA science community. NOAA's focus has been on refining a suite of operational products known as Environmental Data Records (EDRs), which were developed according to project specifications under the National Polar-Orbiting Environmental Satellite System. The NASA S-NPP Science Team has focused on evaluating the EDRs for science use, developing and testing additional products to meet science data needs, and providing MODIS data product continuity. This paper presents to-date findings of the NASA Science Team's evaluation of the VIIRS land and cryosphere EDRs, specifically Surface Reflectance, Land Surface Temperature, Surface Albedo, Vegetation Indices, Surface Type, Active Fires, Snow Cover, Ice Surface Temperature, and Sea Ice Characterization. The study concludes that, for MODIS data product continuity and earth system science, an enhanced suite of land and cryosphere products and associated data system capabilities are needed beyond the EDRs currently available from the VIIRS.

  8. Vicarious calibration of S-NPP/VIIRS day-night band

    NASA Astrophysics Data System (ADS)

    Shao, Xi; Cao, Changyong; Uprety, Sirish

    2013-09-01

    The Day Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite provides imagery of clouds and other Earth features over illumination levels ranging from full sunlight to quarter moon. In order to cover this extremely broad measurement range, the DNB employs four imaging arrays that comprise three gain stages. The low gain stage (LGS) gain values are determined by solar diffuser data. In operation, the medium and high gain stage values are determined by multiplying the LGS gains by the medium gain stage (MGS)/LGS and high gain stage (HGS)/LGS gain ratios, respectively. This paper demonstrates a scheme of using DNB observation of ground vicarious sites under lunar illumination at night to independently verify the radiometric accuracy of HGS of DNB. We performed vicarious calibration of DNB when S-NPP flies above the vicarious site such as Dome C in Antarctic and Greenland in northern hemisphere at night and the moon illuminates the site with lunar phase being more than half moon. Lunar spectral irradiance model as a function of Sun-Earth-Moon distances and lunar phase is used to assist the determination of top-of-atmosphere reflectance at the vicarious site. Analysis of the vicariously-derived reflectance from DNB observations show agreement with the reflectance derived from Hyperion observations of the vicarious sites.

  9. Reactor Dosimetry Aspects of the Service Life Extension of the Hungarian Paks NPP

    NASA Astrophysics Data System (ADS)

    Zsolnay, Eva M.; Czifrus, Szabolcs; Fehér, Sándor; Hordósy, Gábor; Keresztúri, András; Kresz, Norbert; Oszvald, Ferenc

    2016-02-01

    The service life of the Hungarian Paks Nuclear Power Plant (NPP) will be extended from the originally planned 30 years to 50 years. To improve the reliability of the results obtained in frame of the old reactor pressure vessel (RPV) surveillance programme, new methods have been developed, and based on them, the old exposition data have been re-evaluated for all the four reactor units. At the same time, a new RPV surveillance programme has been developed and introduced, and long term irradiations have been performed to determine the radiation damage of the surveillance specimens due to the high fast neutron exposition. Neutron transport calculations have been performed with a validated neutron transport code system to determine the fast neutron exposition of the RPVs during the extended service life. The cavity dosimetry is in the introductory phase. This paper presents the new developments in the field of the RPV surveillance dosimetry and summarises the results obtained. According to the results the service life of the NPP can safely be extended for the planned 50 years.

  10. N-Glycomic and Microscopic Subcellular Localization Analyses of NPP1, 2 and 6 Strongly Indicate that trans-Golgi Compartments Participate in the Golgi to Plastid Traffic of Nucleotide Pyrophosphatase/Phosphodiesterases in Rice

    PubMed Central

    Kaneko, Kentaro; Takamatsu, Takeshi; Inomata, Takuya; Oikawa, Kazusato; Itoh, Kimiko; Hirose, Kazuko; Amano, Maho; Nishimura, Shin-Ichiro; Toyooka, Kiminori; Matsuoka, Ken; Pozueta-Romero, Javier; Mitsui, Toshiaki

    2016-01-01

    Nucleotide pyrophosphatase/phosphodiesterases (NPPs) are widely distributed N-glycosylated enzymes that catalyze the hydrolytic breakdown of numerous nucleotides and nucleotide sugars. In many plant species, NPPs are encoded by a small multigene family, which in rice are referred to NPP1–NPP6. Although recent investigations showed that N-glycosylated NPP1 is transported from the endoplasmic reticulum (ER)–Golgi system to the chloroplast through the secretory pathway in rice cells, information on N-glycan composition and subcellular localization of other NPPs is still lacking. Computer-assisted analyses of the amino acid sequences deduced from different Oryza sativa NPP-encoding cDNAs predicted all NPPs to be secretory glycoproteins. Confocal fluorescence microscopy observation of cells expressing NPP2 and NPP6 fused with green fluorescent protein (GFP) revealed that NPP2 and NPP6 are plastidial proteins. Plastid targeting of NPP2–GFP and NPP6–GFP was prevented by brefeldin A and by the expression of ARF1(Q71L), a dominant negative mutant of ADP-ribosylation factor 1 that arrests the ER to Golgi traffic, indicating that NPP2 and NPP6 are transported from the ER–Golgi to the plastidial compartment. Confocal laser scanning microscopy and high-pressure frozen/freeze-substituted electron microscopy analyses of transgenic rice cells ectopically expressing the trans-Golgi marker sialyltransferase fused with GFP showed the occurrence of contact of Golgi-derived membrane vesicles with cargo and subsequent absorption into plastids. Sensitive and high-throughput glycoblotting/mass spectrometric analyses showed that complex-type and paucimannosidic-type glycans with fucose and xylose residues occupy approximately 80% of total glycans of NPP1, NPP2 and NPP6. The overall data strongly indicate that the trans-Golgi compartments participate in the Golgi to plastid trafficking and targeting mechanism of NPPs. PMID:27335351