An exploratory sensitivity study with the MELCOR Accident Consequence Code System (MACCS) is presented. This study was performed to provide (1) an indication of the possible impact of consequence modeling uncertainties on the results of an integrated prob...
National Technical Information Service (NTIS)
The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was developed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. ...
The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. ...
The MELCOR Accident Consequence Code System (MACCS) has been applied to the radiological consequence assessment of potential accidents from a non-reactor nuclear facility. MACCS has been used in a variety of applications to evaluate radiological dose and ...
The joint USNRC/CEC consequence uncertainty study was chartered after the development of two new probabilistic accident consequence codes, MACCS in the U.S. and COSYMA in Europe. Both the USNRC and CEC had a vested interest in expanding the knowledge base...
Cheap and clean energy can be supplied with nuclear power plant whose accident probability is very low comparing with that of the other industrial facilities. However, the consequences of severe accident of nuclear power plant may result in a critical imp...
The FORTRAN-IV computer code UFOMOD calculates the radiological consequences of reactor accidents for risk studies, namely early deaths, latent cancer deaths and genetic significant doses. Different models for the atmospheric transport and deposition, the...
This volume is the second of a two-volume document that summarizes a joint project conducted by the US Nuclear Regulatory Commission and the European Commission to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. Thes...
This volume is the first of a two-volume document that summarizes a joint project conducted by the US Nuclear Regulatory Commission and the European Commission to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These...
This paper is concerned with the application of severe-accident codes to develop improved accident mitigation strategies for nuclear power plants employing boiling water reactors (BWRs). Specifically, the results of analyses using the APRIL.MOD3X code are presented for typical station blackout ...
Energy Citations Database
This document has been prepared as a user's guide for the computer program RISKIN developed at Sandia National Laboratories. The RISKIN code generates integrated risk tables and the weighted mean risk associated with a user-selected set of consequences from up to five output files generated by the MELCOR Accident ...
DOE Information Bridge
The ORION code is designed to determine very quickly the immediate consequences (such as plume passage time, instantaneous maximum hazards irradiation, inhalation, deposit) due to an accident spreading out radioactive or chemical pollution into the atmosp...
The implementation of SEDA 2.0 computer code, developed at Ezeiza Atomic Center, Argentine for Angra 1 reactor is described. The SEDA code gives an estimate for radiological consequences of nuclear accidents with release of radiactive materials for the en...
A number of computer codes have been written to attempt to predict the consequences of hypothetical accidents. These codes all have one thing in common: they produce reams of paper containing vast quantities of numbers. In an effort to make these numbers ...
In this paper, a simple analytical code, QUASAR, is developed to analyze the phenomena related to severe subassembly accidents, such as a total instantaneous blockage event for a subassembly inlet. The code models failed and neighboring subassemblies, focusing mainly on the thermal consequences and the propagation ...
An assessment of the radiological consequences that would result for the population of Greece from postulated major nuclear accidents in the Kozloduy nuclear power station in Bulgaria is performed. Kozloduy lies at a distance of 225 km from the northern borders of Greece and contains six reactors, all of the Russian WWER type. The postulated ...
MACCS2 represents a major enhancement of the capabilities of its predecessor MACCS, the MELCOR Accident Consequence Code System. MACCS was developed to estimate the potential impacts to the surrounding public of severe accidents at nuclear power plants. T...
Although hypothetical fast reactor accidents leading to severe core damage are very low probability events, their consequences are to be assessed. During such accidents, one can envisage the ejection of sodium, mixed with fuel and fission products, from t...
This paper describes a multilaboratory research program that is directed toward addressing many questions that analysts face when performing air cleaning accident consequence assessments. The program involves developing analytical tools and supportive experimental data that will be useful in making more realistic assessments of ...
Response surface techniques have been developed for obtaining probability distributions of the consequences of postulated nuclear reactor accidents. The probabilistic response surface methodology reported includes new knot-point selection schemes and response surface functions, functional transformations of both parameters and ...
The MELCOR Accident Consequence Code System (MACCS) has been applied to the radiological consequence assessment of potential accidents from a non-reactor nuclear facility. MACCS has been used in a variety of applications to evaluate radiological dose and health effects to the public from ...
The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US ...
The development of radiological consequence lookup tables for postulated releases of radionuclides commonly used at Savannah River Site (SRS) and other Department of Energy (DOE) facilities requires the use of the MELCOR Accident Consequence Code System (...
Techniques for probabilistic response-surface analysis have been developed to obtain the probability distributions of the consequences of postulated nuclear-reactor accidents. The uncertainties of the consequences are caused by the variability of the syst...
An uncertainty and sensitivity analysis of early health consequences of severe accidents at nuclear power plants as a function of the emergency response parameters has been performed using a probabilistic consequence assessment code. The importance of various emergency response parameters in predicting the ...
This report describes development of a revised Savannah River Site (SRS) meteorological data set for the MELCOR Accident Consequence Code System (MACCS). This data set contains quality assured values of transport wind direction, wind speed, atmospheric st...
The RADionuclide Transport, Removal, And Dose (RADTRAD) code is designed for US Nuclear Regulatory Commission (USNRC) use to calculate the radiological consequences to the offsite population and to control room operators following a design-basis accident ...
The RADTRAN 4 computer code is designed to analyze radiological consequences and accident risks of transporting radioactive material. This manual provides information useful for interpreting, troubleshooting, or debugging components of the code during development or revision of the program.
This report presents the results of an evaluation of the probabilities and consequences of accidents involving shipments of radioactive materials (RAM) contained in multiple Type A packages. On the basis of previous studies as well as highway and air accident experience, the exposure doses from three generic multiple-package shipments ...
APRIL is a fast-running and user-friendly system code for interactive simulations of severe accidents in boiling water reactors (BWRs). The component models in the most recent version, APRIL.MOD3X, include the reactor core and pressure vessel, as well as the primary and secondary containments. Whereas APRIL.MOD3X is a fast-running ...
This volume is the first of a two-volume document that summarizes a joint project conducted by the US Nuclear Regulatory Commission and the European Commission to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These codes were developed primarily for estimating the risks ...
Within the framework of a danger analysis which serves as a decision-finding basis for emergency planning, rarely expected severe accidents, which are not covered by design basis accidents, have to be considered at the Rossendorf research site with regard...
A version of the CRAC2 computer code applicable for use in analyses of consequences and risks of reactor accidents in case work for environmental statements has been implemented for use on the Nuclear Regulatory Commission Data General MV/8000 computer sy...
With respect to the application of the accident consequence model of the German Risk Study (GRS) for light water reactors to risk assessments of other reactor types (high temperature reactor HTR-1160, fast breeder reactor SNR-300), the improved version UF...
The Commission of the European Communities and the Nuclear Energy Agency of the OECD have organized an international exercise to compare the predictions of accident consequence assessment codes, and to identify those features of the models which lead to differences in the predicted results. Alongside this, a further exercise was ...
This paper reports on the UFOMOD program system which is an advanced probabilistic accident consequence assessment (ACA) code. Its structure and modeling are based on the experience gained from applications of the old UFOMOD code during and after the German Risk Study Phase A, the results of scientific ...
Response-surface techniques have been developed for obtaining probability distributions of the consequences of postulated nuclear reactor accidents. In these techniques, probability distributions are assigned to the system and model parameters of the accident analysis. A limited number of parameter values (called knot points) are ...
In recent years, a number of advanced, best-estimate systems codes such as TRAC and RELAP5 have been developed in order to accurately predict the consequences of various postulated accidents and transients in Light Water Reactor (LWR) systems. Although th...
Dose calculations were performed using the MELCOR Accident Consequence Code System (MACCS) to support safety analyses for the Los Alamos Neutron Science Center (LANSCE) facility. The LANSCE facility is operated and maintained at Los Alamos National Labora...
Radiological impacts of transporting radioactive material by truck, air, rail, and water can be analyzed with the RADTRAN code. Consequences of incident-free transportation (also referred to as normal or accident-free transportation) as well as risks from...
Preliminary accident consequence assessments have been performed with the computer code UFOMOD to study the significance of the ingestion pathway in accidental releases with actinides. The investigation was based on the release category K1 of the 'Risk Or...
The consequences of an earthquake-induced fire involving a tritium leak were analyzed using the GASFLOW computer code. Modeling features required by the analysis include ventilation boundary conditions, flow of a gas mixture in an enclosure containing obs...
The consequences of an earthquake-induced fire involving a tritium leak were analyzed using the GASFLOW computer code. Modeling features required by the analysis include ventilation boundary conditions, flow of a gas mixture in an enclosure containing obstacles, thermally induced buoyancy, and combustion phenomena.
In the intervening period since the first conception of the accident consequence model UFOMOD of the German Risk Study, new scientific information has accumulated. Important are the newest recommendations of the ICRP 30 concerning the calculation of the d...
The review was undertaken to assist the NRC in determining whether or not to revise the models. The models are presented in the RSS and as implemented in the CRAC (Calculations of Reactor Accident Consequences) Code are described and critiqued. The major ...
The radiological analyses of extreme hypothetical accidents were performed almost wholly by computer techniques. Major analytical codes used were RIBD, CACECO, SPRAY, HAA, and COMRADEX. This paper describes the analyses, the modeling techniques, and transition programs that edited data output from one code into a form suitable for ...
Regardless low probability of occurrence the severe accident phenomena are investigated for all types of nuclear reactors in the world because the consequences of such accident could be catastrophic. Most of research is performed for the prevailing vessel-type light water reactors like PWRs and BWRs. Less research is performed for the ...
To ensure that the public health and safety are protected under any accident conditions in a Liquid Metal Fast Breeder Reactor (LMFBR), many accidents are analyzed for their potential consequences. The SAS4A code system, described in this paper, provides such an analysis capability, including the ability to analyze ...
about homeland security research. Browse these EPA Emergency Response subtopics Accidents Accident Preparedness, Accident Prevention, Chemical Accidents, Radiation Accidents...
Science.gov Websites
This paper briefly describes an ongoing project designed to assess the uncertainty in offsite radiological consequence calculations of hypothetical accidents in commercial nuclear power plants. This project is supported jointly by the Commission of European Communities (CEC) and the US Nuclear Regulatory Commission (USNRC). Both commissions have expressed ...
This report identifies the results of a program aimed at developing a computer code for use in the analysis of the behavior of iodine during steam generator tube rupture (SGTR) accidents in pressurized water reactors (PWR's). The program was directed towards the identification of the several processes that play a role in the transport and ...
A number of computer codes have been written to attempt to predict the consequences of hypothetical accidents. These codes all have one thing in common: they produce reams of paper containing vast quantities of numbers. In an effort to make these numbers more comprehensible, certain graphical techniques have been ...
The in-depth reviews of risk assessments performed specifically for the Limerick and Shoreham plants have identified accident sequences that are important contributors to core damage frequency (CDF). These plants are boiling water reactors (BWRs) with Mark-II containment designs. Plant features and operator actions that have been found to be important for either preventing or ...
An independent quality assurance (QA) and verification of Version 1.5 of the MELCOR Accident Consequence Code System (MACCS) was performed. The QA and verification involved examination of the code and associated documentation for consistent and correct implementation of the models in an error-free FORTRAN computer ...
The lradiological a consequences of the Chernobyl accident Proceedings of the first international conference
E-print Network
The TRANSIT-HYDRO computer code is being developed to provide a tool for assessing the consequences of transition phase events in a hypothetical core disruptive accident in an LMFBR. The TRANSIT-HYDRO code incorporates detailed geometric modeling on a subassembly-by-subassembly basis and detailed modeling of ...
RESOLVE! Version 2 .5 is designed to quantify the risk and uncertainty of combustion accidents in double-shell tanks (DSTs) and single-shell tanks (SSTs). The purpose of the acceptance testing is to ensure that all of the options and features of the computer code run; to verify that the calculated results are consistent with each other; and to evaluate the ...
In this paper, the whole-core reactivity consequences of internal fuel motion in annular fuel during hypothetical 50 cents/s and 3 cents/s transient overpower (TOP) accidents are compared using results calculated by the MELT-IIIB/FUMO-E code to determine ...
This paper presents the results of a systematic study of the effectiveness of intrinsic design features to mitigate the consequences of unprotected accidents in metallic and oxide-fueled LMFBRs. The accidents analyzed belong to the class generally considered to lead to core disruption; unprotected loss-of-flow (LOF) and transient ...
At the international level the Chernobyl accident reemphasized the importance of long-range air pollution effects and in Portugal the need for assessment of the likely environmental and socioeconomic impacts of a hypothetical accident in a Spanish nuclear power plant to anticipate eventual protective and mitigating actions was emphasized. Although no ...
... Accession Number : AD0620258. Title : FURTHER ATTEMPTS AT CODING AIRCRAFT ACCIDENTS. Descriptive Note : Research rept.,. ...
DTIC Science & Technology
... AD0076065. Title : CODED FLEET ACCIDENTS OF RECENT GRADUATES. Corporate Author : TULANE UNIV NEW ORLEANS LA. ...
Assessment of the environmental consequences of an accident in a fuel cycle facility ultimately involves calculating the atmospheric dispersion of radioactive materials and estimating the radiation dose to the surrounding population. Some uncertainty lies in the estimate of the nuclear facility source term to be used for atmospheric dispersion ...
An interactive simulation code for studying postulated heatup accidents in modular high-temperature gas-cooled reactors (MHTGRs) has been adapted to assist with parametric design studies of the US Department of Energy`s (DOE`s) direct-cycle gas-turbine MHTGR concept. The studies show that the proposed MHTGR designs are very robust and can generally ...
The Commission of the European Communities, within the framework of radiation protection research program, initiated a project entitled Methods for Assessing the Radiological Impact of Accidents (MARIA). This project was continued and enlarged within the 1985-1989 research program. The main objectives of this paper are to develop a new probabilistic ...
The objective of this paper is to assess proposed transuranic waste accident analysis guidance and recent software improvements in a Windows-OS version of MACCS2 that allows the inputting of parameter uncertainty. With this guidance and code capability, there is the potential to perform a quantitative uncertainty assessment of unmitigated ...
This report presents a set of precalculated doses based on a set of postulated accident releases and intended for use in emergency planning and emergency response. Doses were calculated for the PWR (Pressurized Water Reactor) accident categories of the Reactor Safety Study (WASH-1400) using the CRAC (Calculations of Reactor Accident ...
This paper discusses salient aspects of methodology, assumptions, and modeling of various features related to estimation of source terms from two conservatively scoped severe accident scenarios in the Advanced Neutron Source (ANS) reactor at the Oak Ridge National Laboratory. Various containment configurations are considered for steaming-pool-type ...
Although the early carbide fuel tests in the Fast Test Reactor (FTR) are less than subassembly size, the long-term irradiation program provides for an eventual loading of up to 14 carbide subassemblies (S/As). This work compares the transient overpower (TOP) accident consequences of the FTR partial carbide core with the safety envelope established for the ...
The development of two new probabilistic accident consequence codes, MACCS and COSYMA, completed in 1990, estimate the risks presented by nuclear installations based on postulated frequencies and magnitudes of potential accidents. In 1991, the US Nuclear Regulatory Commission (NRC) and the Commission of the ...
The fundamental objective of the accident management program is to assure, in the event of a severe accident at a nuclear plant, that the effectiveness of personnel and equipment is maximized in preventing or mitigating the consequences of the accident. T...
For a long time in the Russian Federation the computer code for analysis of severe accidents is being developed. The main peculiarity of this code from the known computer codes for analysis of severe accidents at NPP such as MELCOR and ASTEC, is a consequent realization of ...
Anticipated Transients Without Scram (ATWS) accident analyses make part of the Safety Analysis Report of the European Pressurized water Reactor (EPR), covering Risk Reduction Category A (Core Melt Prevention) events. This paper deals with three of the most penalizing RRC-A sequences of ATWS caused by mechanical blockage of the control/shutdown rods, regarding their ...
The International Thermonuclear Experimental Reactor (ITER) Program is performing accident analyses for ITER�s �Rapport Préliminaire de Sûreté� (Report Preliminary on Safety - RPrS) with a modified version of the MELCOR 1.8.2 code. The RPrS is an ITER safety document required in the ITER licensing process to obtain a �Décret Autorisation de ...
The International Thermonuclear Experimental Reactor (ITER) Program is performing accident analyses for ITER�s �Rapport Pr�liminaire de S�ret� (Report Preliminary on Safety - RPrS) with a modified version of the MELCOR 1.8.2 code. The RPrS is an ITER safety document required in the ITER licensing process to obtain a �D�cret Autorisation de ...
The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the risks presented by nuclear installations based on postulated frequencies and magnitudes of potential accidents. In 1991, the US Nuclear Regulatory Commission ...
This report is a summary of the material transport modeling procedures developed to support a family of accident analysis computer codes. The material transport modeling areas include transport initiation, convection, interaction, depletion, and filtration. Except for material interaction, these areas are developed in modular form in three Los Alamos ...
MACCS, Chronic, Exposure Pathway, Models: Review the chronic exposure pathway models implemented in the MELCOR Accident Consequence Code System (MACCS) and compare those models to the chronic exposure pathway models implemented in similar codes developed ...
The Idaho National Laboratory�s PEBBED code and simple probability considerations are used to estimate the likelihood and consequences of the accumulation of highly reactive pebbles in the region of peak power in a pebble-bed reactor. The PEBBED code is briefly described, and the logic of the probability calculations is presented in ...
The purpose of this report is to estimate the consequences of a Hanford reactor accident with emphasis on the effects at distant points. The potential effects in Canada are estimated as well as the consequences within the United States.
This thesis describes a complete methodology which has allowed for the development of a faster than real time computer program designed to simulate a small break loss -of-coolant accident in the primary system of a pressurized water reactor. By developing an understanding of the major phenomenon governing the small break LOCA fluid response, the system model representation can ...
NASA Astrophysics Data System (ADS)
The task described in this paper was performed for the U.S. Nuclear Regulatory Commission. The chronic exposure pathway models implemented in the MELCOR Accident Consequence Code System (MACCS) were compared to post-Chernobyl data from various sources, though mainly from Norway, for verification or identification of areas for possible ...
Because of the complexity, volume of data and calculations required, one preferred analytical tool to perform transportation risk assessments is the RADTRAN computer code. RADTRAN combines user-determined material, packaging, transportation, demographic and meteorological factors, with health physics data to calculate expected radiological consequences and ...
This report describes the MACCS computer code. The purpose of this code is to simulate the impact of severe accidents at nuclear power plants on the surrounding environment. MACCS has been developed for the US Nuclear Regulatory Commission to replace the previously used CRAC2 code, and it incorporates many ...
Jan 11, 2011 ... trajectories and potential reentry accidents and environments. .... Environmental Consequences of Potential Accidents ...
NASA Website
In recent years, a number of advanced, best-estimate systems codes such as TRAC and RELAP5 have been developed in order to accurately predict the consequences of various postulated accidents and transients in Light Water Reactor (LWR) systems. Although these codes had to go through some verification or assessment ...
One consequence of the accident at the Three Mile Island Unit 2 (TMI-2) nuclear power plant is a realization by the nuclear power technical community that there is a need for calculational tools that can be used to analyze the TMI-2 accident and to investigate hypothetical situations involving degraded light-water reactor (LWR) cores. ...
This report contains technical information used to determine accident consequences for the Spent Nuclear Fuel Project safety documents. It does not determine accident consequences or describe specific accident scenarios, but instead provides generic information.
...mitigate the consequences of an accident; (ii) The equipment...relied on to prevent potential accidents or mitigate their consequences...relied on to prevent potential accidents or mitigate their consequences...evaluated in the Integrated Safety Analysis. (d) The ...
Code of Federal Regulations, 2011
The analysis of the risks of transporting irradiated nuclear fuel to a federal repository, Appendix A of the DOE Environmental Assessment for Yucca Mountain (DOE84), is based on the RADTRAN model and input parameters. The RADTRAN computer code calculates the radiation exposures and health effects under normal or incident-free transport, and over all credible ...
Effective planning for the management of severe accidents at nuclear power plants can produce both a reduction in the frequency of such accidents as well as the ability to mitigate their consequences if and when they should occur. This report provides an ...
After some indications on the Chernobylsk power plant and the characteristics of the RBMK series, the scenario of the accident is developed. The immediate consequences and the control of the accident are commented before concluding on more general lessons...
The hypothetical core disruptive accident in an LMFBR is discussed under the following main headings: reactor dynamics; mechanical consequences; and post- accident heat removal. 79 references. (DCC)
The impact on society of the Chernobyl accidents is assessed. The situation prior to Chernobyl with respect to regulations of radiation protection against the consequences of a major accident is considered. The development of the recommendations and regul...
In this report information about the nuclear accident at Chernobyl and the radioactivity burdening of Greece from the radioactive releases of the accident are presented. The main characteristics of the RBMK-1000 reactor and the flow pattern of the radioac...
The report describes the Chernobyl accident and its consequences for Denmark in particular. It was commissioned by the Secretary of State for the Environment. The event at the accident site, the release and dispersal of radioactive substances into the atm...
It is prerequisite for the establishment of nuclear power plant safety and for the maximization of operation efficiency to devlope the accident analysis computer code packages which can predict the results of postulated accidents and evaluate the performa...
In the licensing process for an LMFBR, the margins for safety are determined by considering many accident sequences that are within the design basis for the plant. However, to establish the safety margin beyond the design basis, also considered are accidents that have an extremely low probability of occurrence but the potential for significant ...
It summarizes the consequences in Sweden of the Chernobyl accident, describes the emergency response, the basis for decisions and countermeasures, the measurement strategies, the activity levels and doses and countermeasures and action levels used. Past a...
The VICTORIA code is designed to be a module of the MELPROG severe accident analysis code. The VICTORIA code is designed to model the in-vessel phase of a severe reactor accident. The functions of VICTORIA in MELPROG are fission product release from fuel,...
The goal of this work is the investigation of the influence of different accident management strategies on the thermal-hydraulics in the containment during a Large Break Loss of Coolant Accident with a large containment leak from the beginning of the accident. The increasing relevance of terrorism suggests a closer look at this kind of ...
This report presents the technical details of RISKIND, a computer code designed to estimate potential radiological consequences and health risks to individuals and the collective population from exposures associated with the transportation of spent nuclear fuel. RISKIND is a user-friendly, interactive program that can be run on an IBM or equivalent ...
The primary objective of the Probabilistic Safety Assessment (PSA) at the U. S. Department of Energy (DOE) Savannah River Site (SRS) is to quantify health and economic risks posed by K Reactor operation to the nearby offsite and onsite areas from highly unlikely severe accidents. The overall risk analyses have also been instrumental as defensible bases for analyzing existing ...
An assessment of UF{sub 6} release accidents was conducted for the feed facility of a gaseous diffusion plant. The MELCOR code was utilized for simulating the reactions of UF{sub 6} with moisture and the consequent transport of UO{sub 2}F{sub 2} aerosols and HF vapor through the building and to the environment.
The Nuclear Regulatory Commission uses MACCS2 (MELCOR Accident Consequence Code System, Version 2) for regulatory purposes such as planning for emergencies and cost-benefit analyses. MACCS2 uses a straight-line Gaussian model for atmospheric transport and...
In the framework of pressurized water reactor severe accidents, the MOD code studies steam explosion from its triggering and escalation stage to the propagation and possible steady-state stage of the interaction. The triggering of vapor explosion is induced by thermal fragmentation caused by a pressure wave. In MOD, the fine fragmentation is described by ...
One of the most important safety design issues for a hydrogen production system coupling with a high-temperature gas-cooled reactor (HTGR) is to ensure reactor safety against fire and explosion accidents because a large amount of combustible fluid is dealt with in the system. The Japan Atomic Energy Research Institute has a demonstration test plan of a hydrogen production ...
The RADionuclide Transport, Removal, And Dose (RADTRAD) code is designed for US Nuclear Regulatory Commission (USNRC) use to calculate the radiological consequences to the offsite population and to control room operators following a design-basis accident at Light Water Reactor (LWR) power plants. This code utilizes ...
ECART can simulate the thermal-hydraulic behavior of LWR and GCR plants under severe accident conditions together with the transport of radio-toxic substances. This tool is still under improvement and assessment for new applications in non-nuclear risk studies, new advanced and fusion reactors. As regards accidents with fires within closed environments, ...
A preliminary computational fluid dynamics (CFD) analysis was performed to understand density-gradient-induced stratified flow in a Very High Temperature Reactor (VHTR) air-ingress accident. Various parameters were taken into consideration, including turbulence model, core temperature, initial air mole-fraction, and flow resistance in the core. The gas turbine modular helium ...
The initial activities of a Department of Energy (DOE) Safety Analysis Software Group to establish a Safety Analysis Toolbox of computer models are discussed. The toolbox shall be a DOE Complex repository of verified and validated computer models that are configuration-controlled and made available for specific accident analysis applications. The toolbox concept was ...
The Defense Programs (DP) Office of Engineering and Operations Support (DP-62) requested SAIC to organize and conduct a survey-level evaluation of 27 DP non-reactor nuclear facilities. The purpose of the evaluation was to provide a consistent scoping effort to estimate, with high confidence, bounding accident consequences for hazards associated with DP ...
This booklet is written to help the untrained accident investigator perform a type C'' accident investigation. It is designed to identify the philosophy of accident investigation, the steps involved, the potential problems in the investigation, and give instruction for completing the DOE 5484 X form. A hypothetical ...
This booklet is written to help the untrained accident investigator perform a type ``C`` accident investigation. It is designed to identify the philosophy of accident investigation, the steps involved, the potential problems in the investigation, and give instruction for completing the DOE 5484 X form. A hypothetical ...
This report describes development of a revised Savannah River Site (SRS) meteorological data set for the MELCOR Accident Consequence Code System (MACCS). This data set contains quality assured values of transport wind direction, wind speed, atmospheric stability class, and precipitation for all hours in each of the five years ...
An uncertainty/sensitivity analysis performed with the MACCS computer code for the early health effects associated with a severe nuclear reactor accident is described. Results obtained in this study indicate that (1) the impact of consequence modeling uncertainty in an integrated risk assessment may be significant; (2) dominant ...
The primary system of a pressurized water reactor (PWR) operates at a relatively high pressure (15.5 MPa, 2250 psia) and consists of piping and components designed to withstand these pressures. The low-pressure-injection system (LPIS) connects to the primary system but possesses low-pressure piping passing outside the containment. Therefore, a potential exists for a loss-of-coolant ...
This paper describes work done at the Oak Ridge National Laboratory (ORNL) for evaluating the potential and resulting consequences of a hypothetical criticality accident during refueling of the 330-MW Advanced Neutron Source (ANS) research reactor. The development of an analytical capability is described. Modeling and problem formulation were conducted ...
A probabilistic risk assessment and consequence analysis for a BWR with a Mark-II containment design has shown that overpressurization is the dominant containment failure mode for a wide range of potential core meltdown accidents. This failure mode is a major contributor to the predicted off-site health consequences. Mitigation of this ...
The nuclear risk analysis of the Cassini mission is one of the most comprehensive risk analyses ever conducted for a space nuclear mission. The complexity of postulated accident scenarios and source term definitions, from launch to Earth swingby, has necessitated an extensive series of analyses in order to provide best-estimates of potential consequence ...
The consequences of an accidental beam loss in superconducting accelerators and colliders of the next generation range from the mundane to rather dramatic, i.e., from superconducting magnet quench, to overheating of critical components, to a total destruction of some units via explosion. Specific measures are required to minimize and eliminate such events as much as practical. ...
The joint USNRC/CEC consequence uncertainty study was chartered after the development of two new probabilistic accident consequence codes, MACCS in the U.S. and COSYMA in Europe. Both the USNRC and CEC had a vested interest in expanding the knowledge base of the uncertainty associated with ...
An overview of the analysis of core-disruptive accidents is given. These analyses are for the purpose of understanding and predicting fast reactor behavior in severe low probability accident conditions, to establish the consequences of such conditions and to provide a basis for evaluating consequence limiting ...
This report presents a comparison between two computerized methodologies for estimating the radiation dose to man from radionuclide releases to the atmosphere. The COMRADEX-IV code was designed to provide a means of assessing potential radiological consequences from postulated power reactor accidents. The AIRDOS-EPA ...
Over the past three years (1991-1993), an extensive international exercise for intercomparison of a group of six Probabilistic Consequence Assessment (PCA) codes was undertaken. The exercise was jointly sponsored by the Commission of European Communities (CEC) and OECD Nuclear Energy Agency. This exercise was a logical continuation of a similar effort ...
