In support of the Accident Sequence Precursor Program (ASP), the U.S. Nuclear Regulatory Commission (NRC), in conjunction with the Idaho National Laboratory (INL), in 1994 developed the Accident Sequence Precursor Standardized Plant Analysis Risk Model (A...
National Technical Information Service (NTIS)
The Accident Sequence Precursor (ASP) Program at ORNL analyzed about 14.000 Licensee Event Reports (LERs) filed by US nuclear power plants 1987--1993. There were 193 events identified as precursors to potential severe core accident sequences. These are re...
A computer algorithm has been developed and implemented to search the Sequence Coding and Search System Licensee Event (LER) database for failures or conditions common to Accident Sequence Precursor (ASP) events. Use of the algorithm has greatly improved the efficiency and timeliness in identifying potential ASP ...
DOE Information Bridge
This report covers work to develop a methodology for analyzing precursors to both earthquake-initiated and fire-initiated accidents at commercial nuclear power plants. Currently, the U.S. Nuclear Regulatory Commission sponsors a large ongoing project, the Accident Sequence Precursor project, to ...
Abstract: Accident Precursor Analjsi.7 (APA) serves as the bridge between ... differences in the nature and objectives of accident precursor analysis at ...
NASA Website
NASA's Accident Precursor Analysis Process and the International Space Station. Trilateral Safety and Mission Assurance Conference ...
The Accident Sequence Precursor Program reviews licensee event reports of operational events that have occurred at LWRs to identify and categorize precursors to potential severe core-damage accidents. Accident sequences considered in the study are those ...
Energy Citations Database
Changes in the US NRC Accident Sequence Precursor program methods since the initial program evaluations of 1969-81 operational events are described, along with insights from the review of 1984-85 events. For 1984-85, the number of significant precursors was consistent with the number observed in 1980-81, dominant ...
The Accident Sequence Precursor (ASP) Program at ORNL analyzed about 14.000 Licensee Event Reports (LERs) filed by US nuclear power plants 1987--1993. There were 193 events identified as precursors to potential severe core accident sequences. These are reported in ...
Safety is a crucial issue in densely sailed waterways. Traffic guidance systems (VTS) have proven to be valuable in this respect. The effectiveness of current systems and the benefits for improvements in navigation are addressed in this paper. Relevant incidents are analysed with a risk assessment tool (Accident Sequence Precursor ...
NASA Astrophysics Data System (ADS)
Abstract: Accident Precursor Analysis (APA) serves as the bridge between existing risk modeling activities, which are often based on historical or generic ...
The Nuclear Regulatory Commission`s (NRC`s) ongoing Accident Sequence Precursor (ASP) program uses probabilistic risk assessment (PRA) techniques to assess the potential for severe core damage (henceforth referred to simply as core damage) based on operating events. The types of operating events considered include ...
The 1994 Accident Sequence Precursor (ASP) human reliability analysis (HRA) methodology was developed for the U.S. Nuclear Regulatory Commission (USNRC) in 1994 by the Idaho National Engineering and Environmental Laboratory (INEEL). It was decided to revi...
Sensitivity studies based on Probabilistic Safety Assessments (PSAs) for a pressurized water reactor and a boiling water reactor are described. In each case human errors modeled in the PSAs were categorized according to such factors as error type, location, timing, and plant personnel involved. Sensitivity studies were then conducted by varying the error rates in each category and evaluating the ...
The inputs to the accident sequence evaluation include the system fault tree models and the event tree models. Each event tree sequence defines a unique accident sequence. The qualitative analysis of an accident sequence is concerned with determining ...
Aug 1, 2005 ... new software may help analysts identify the precursors of incidents or accidents . "The Morning Report offers a promising method for ...
Severe accident management can be defined as the use of existing and/or alternative resources, systems and actors to prevent or mitigate a core-melt accident. For each accident sequence and each combination of severe accident management strategies, there ...
Jul 15, 2007 ... Knowledge of quantification techniques to assess the probability implications of a precursor event or a precursor sequence events. ...
A strategy has been developed for systematically addressing and handling the hazards posed by a transportation accident involving hazardous materials. The Accident Management Orientation Guide presents this system as a logic sequence of events in a color-...
Information concerning the dominant accident sequences from twelve published probabilistic risk assessments (PRA) is cataloged in this report, which is published as a part of the Accident Sequence Evaluation Program (ASEP). The purpose of the report is to...
This slide presentation reviews the precursor analysis for flight and ground based anomaly risk significance. It includes information on accident precursor analysis, real models vs. models, and probabilistic analysis.
As part of the Severe Accident Sequence Analysis (SASA) program of the Nuclear Regulatory Commission (NRC), threats to containment and ways in which operators can help preserve containment integrity during severe accidents are examined. Severe accidents a...
The report describes a human factors research project performed to: (1) support the Severe Accident Sequence Analysis (SASA) program and (2) develop a descriptive model of operator response in accident management. The first goal was accomplished by workin...
This study developed a set of dominant accident sequences that could be applied generically to domestic commercial PWRs as a standardized basis for a probabilistic seismic risk assessment. This was accomplished by ranking the Zion 1 accident sequences. The pertinent PWR safety systems were compared on a ...
This work presents a quantitative assessment of the impact that the emergency operating instructions (EOIs) of operating nuclear power plants may have on the frequency of severe accident sequences. Frequencies of such sequences were calculated based on th...
The current state of knowledge with respect to the analysis of postulated accident sequences in fast breeder reactors, as well as some implications to fast reactor design, are reviewed. The accidents considered include loss of coolant flow and transient overpower, both with a postulated failure to scram. The associated ...
This report describes analyses of the response of a Pressurized-Water Reactor at the Zion Plant to hypothetical core-meltdown sequences. The analyses consider the progression of core meltdown, containment response, and consequences to the public for many specific accident sequences within the categories of Loss of Coolant ...
Information concerning the dominant accident sequences from twelve published probabilistic risk assessments (PRA) is cataloged in this report, which is published as a part of the Accident Sequence Evaluation Program (ASEP). The purpose of this report is to provide users of PRA information a single reference ...
Prediction of viral microRNA precursors based on human microRNA precursor sequence and structural features
E-print Network
Mar 30, 2011 ... Sequence of Major Events of the Challenger Accident. Image library of the STS- 51L Challenger mission at Johnson Space Center. ...
Continuing research to develop and verify computer models of CANDU-PHW reactor process and safety systems is described. It is focussed on loss-of-coolant accidents (LOCAs) because they are the precursors of more serious accidents. Research topics include:...
system behavior, and because one is trying to avoid certain kinds of behavior deemed to be accidents, one hits earth bank Take away this node, and you've avoided the accident. What are its immediate precursors, and thus avoided the crash altogether. Further Evidence There was a private video made of the accident y
The 1994 Accident Sequence Precursor (ASP) human reliability analysis (HRA) methodology was developed for the U.S. Nuclear Regulatory Commission (USNRC) in 1994 by the Idaho National Engineering and Environmental Laboratory (INEEL). It was decided to revise that methodology for use by the Simplified Plant Analysis Risk (SPAR) program. ...
The steps involved to incorporate parameter uncertainty into the Nuclear Regulatory Commission (NRC) accident sequence precursor (ASP) models is covered in this paper. Three different uncertainty distributions (i.e., lognormal, beta, gamma) were evaluated to Determine the most appropriate distribution. From the evaluation, it was ...
The Parametric Source Term (PST) code has been developed for estimating radioactivity release fractions. The PST code is a framework of equations based on activity transport between volumes in the release pathway from the core, through the vessel, through the containment, and to the environment. The code is fast-running because it obtains exact solutions to differential equations for activity ...
This paper describes the approach taken by the U. S. Nuclear Regulatory Commission to the treatment of common-cause failure in probabilistic risk assessment of operational events. The approach is based upon the Basic Parameter Model for common-cause failure, and examples are illustrated using the alpha-factor parameterization, the approach adopted by the NRC in their Standardized Plant Analysis ...
This report describes the results of safety-evaluation accidents selection by the probabilistic safety analysis method. The accident sequences following on nine initial events were analyzed by means of the event tree method. The occurrence probability (P)...
As part of the Severe Accident Risk Reduction Program, researchers at Sandia National Laboratories have constructed a group of containment event trees to be used in the analysis of key accident sequences for light water reactors (LWR) during postulated se...
A parameter study was carried out for the FRM and the KKE7 core; in this study the effect of the important parameters on the chronological accident sequence and the max. power that was reached was investigated for the startup accident as the limiting case...
The report covers an accident delineation study undertaken to organize and evaluate the available information concerning LMFBR accident sequences and to identify key phenomenological and system-response uncertainties. The study can help provide a basis fo...
The liberation of radioactive materials into various containment locations during a severe accident creates a radiation field that may have a significant impact on the accident progression. High radiation may not only impair the functioning of important e...
...sequence of events leading to the accident or incident, to the extent...the consequences of a launch accident, launch incident, reentry accident, reentry incident, or other...adopt preventive measures for avoiding recurrence of the event....
Code of Federal Regulations, 2011
The current state of knowledge of fast breeder reactors is reviewed. The primary focus on the analysis of postulated accident sequences and the implications to fast-reactor design. The accidents considered include loss-of-collant flow and transient overpower, both with a postulated failure to scram. The associated ...
The paper discusses work conducted to: (1) support the severe accident sequence analysis of a nuclear power plant transient based on an assessment of operator actions, and (2) develop a descriptive model of operator severe accident management. Operator actions during the transient are assessed using qualitative and quantitative ...
The course focuses on the probabilistic quantification of accident sequences and the link between accident sequences and consequences. Previous sessions in this series have focused on the quantification of system reliability (Session A) and the developmen...
For Zion, the following accident sequences were examined: station blackout with failure of auxiliary feedwater (TMLB'), loss of collant accidents (LOCA's) of various sizes inside containment, and the V-sequence interacing system LOCA which involves direct...
The paper will discuss work being conducted during this human factors review including: (1) support of the Severe Accident Sequence Analysis (SASA) Program based on an assessment of operator actions, and (2) development of a descriptive model of operator ...
CONTAIN is an integrated containment thermohydraulic and aerosol transport code. The choice of the Surry plant provides an opportunity to compare the CONTAIN calculations to those recently performed by Battelle Columbus Laboratories. The accident sequence...
A study is reported on the feasibility of the use of microwave dielectric heating to simulate the nuclear heat source in LMFBR 'transition phase' accident sequence volume-boiling simulation experiments. The adequacy of microwave heating is judged based up...
...Integrated safety analysis. (1) Each licensee...an integrated safety analysis, that is of appropriate... (iv) Potential accident sequences caused by...occurrence of each potential accident sequence identified...Integrated safety analysis team...
In support of the US Nuclear Regulatory Commission Accident Management Research Program, the availability of instruments to supply accident management information during a broad range of severe accidents is evaluated for a Boiling Water Reactor with a Mark I containment. Results from this evaluation include: (1) the identification of ...
A case study modeling the thrust reverser system (TRS) in the context of the fatal accident of a Boeing 767 is presented to illustrate the application of Probabilistic Safety Assessment methods. A simplified risk model consisting of an event tree with supporting fault trees was developed to represent the progression of the accident, taking into account the ...
The solution structure of the leader sequence of the patellamide precursor peptide was analysed by using CD and determined with NOE-restrained molecular dynamics calculations. This leader sequence is highly conserved in the precursor peptides of some other cyanobactins harbouring heterocycles, and is assumed to ...
PubMed
This paper highlights the interim results of ASEP. ASEP is one of many programs sponsored by the Nuclear Regulatory Commission (NRC) to study various aspects of severe core damage accidents. The results of ASEP will ultimately focus on identifying the most likely accident sequences and the high risk accident ...
The anatomy of the disaster at the BP refinery. Management and technical problems are highlighted. Factors that are common to many sites are emphasized. Animated sequences show the factors and there effects on the accident sequence.
NSDL National Science Digital Library
Since its inception in October 1980, the Severe Accident Sequence Analysis (SASA) program at Oak Ridge National Laboratory (ORNL) has completed four studies including Station Blackout, Scram Discharge Volume Break, Loss of Decay Heat Removal, and Loss of Injection accident sequences for the Browns Ferry Nuclear ...
The main features of domino accidents in process/storage plants and in the transportation of hazardous materials were studied through an analysis of 225 accidents involving this effect. Data on these accidents, which occurred after 1961, were taken from several sources. Aspects analyzed included the accident ...
Different hypothetical accident sequences have been simulated at Unit 1 of the Juragua nuclear power plant in Cuba, a plant with two VVER-440 V213 units under construction. The computer code MELCOR was employed for these simulations. The sequences simulated are: (1) a design-basis accident (DBA) large loss of ...
The U.S. Nuclear Regulatory Commission is conducting an accident management research program that emphasizes the use of severe accident research to enhance the ability of plant operating personnel to effectively manage severe accidents. Hence, it is necessary to ensure that the plant instrumentation and information systems adequately ...
This paper describes the methodology used in a quantitative hazard assessment of a nuclear weapon disassembly process. Potential accident sequences were identified using an accident-sequence fault tree based on operational history, weapon safety studies, a hazard analysis team composed of weapons experts, and walkthroughs of the ...
