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Title: Severe Accident Modeling: Capability to Address New Challenges ? 2016 Update.


Abstract not provided.

Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: Proposed for presentation at the CSARP/MELCOR User Group Meetings held September 12-16, 2016 in Bethesda, MD.
Country of Publication:
United States

Citation Formats

Gauntt, Randall O. Severe Accident Modeling: Capability to Address New Challenges ? 2016 Update.. United States: N. p., 2016. Web.
Gauntt, Randall O. Severe Accident Modeling: Capability to Address New Challenges ? 2016 Update.. United States.
Gauntt, Randall O. 2016. "Severe Accident Modeling: Capability to Address New Challenges ? 2016 Update.". United States. doi:.
title = {Severe Accident Modeling: Capability to Address New Challenges ? 2016 Update.},
author = {Gauntt, Randall O.},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 9

Other availability
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  • The sound background built-up in LWR source term analysis in case of a severe accident, make it worth to check the capability of LWR safety analysis codes to model accident SFR scenarios, at least in some areas. This paper gives a snapshot of such predictability in the area of aerosol behavior in containment. To do so, the AB-5 test of the ABCOVE program has been modeled with 3 LWR codes: ASTEC, ECART and MELCOR. Through the search of a best estimate scenario and its comparison to data, it is concluded that even in the specific case of in-containment aerosol behavior,more » some enhancements would be needed in the LWR codes and/or their application, particularly with respect to consideration of particle shape. Nonetheless, much of the modeling presently embodied in LWR codes might be applicable to SFR scenarios. These conclusions should be seen as preliminary as long as comparisons are not extended to more experimental scenarios. (authors)« less
  • This three-volume report contains papers presented at the conference. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from France, Japan, Norway, and Russia. The titles of the papers and the names of the authors have been updated and may differ from those that appeared in the final program of the meeting. This volume contains the following information: (1) plenary sessions; (2) pressure vessel research; (3) BWR strainer blockagemore » and other generic safety issues; (4) environmentally assisted degradation of LWR components; and (5) update on severe accident code improvements and applications. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.« less
  • Studies of severe accidents in light water reactors have shown that operator response can play a crucial role in the predicted outcomes of dominant accident scenarios. Although computer codes such as MAAP are available to predict the thermal-hydraulic response, substantial knowledge about plant practices and procedures is needed to make reasonable assumptions about operator response. Based on the thermal-hydraulic state of the plant, symptom-oriented procedures provide general guidance to the operators, who then take one of several possible actions. The paper pictures this process as a feedback loop that relies heavily on the judgment of the individual safety analyst. Themore » ability to more explicitly model the procedural guidance and operator response can help close this analytical loop and improve the overall integration and consistency of severe accident analysis. An object-oriented model for operator response characteristics and symptom-oriented procedures was developed using the NEXPERT OBJECT expert system shell. This prototype system reads MAAP transient output files and determines the instructions and operator response characteristics that are implied by the observable plant variables. A limited set of boiling water reactor (BWR6) emergency operating procedures (EOPs) was formulated as a rule set, and pattern-matching techniques were used to generate message queues for display and reports.« less
  • During 1989, a series of severe reacotr accident tests was performed at the HDR test facility in Karlsruhe, Germany. This facility is a decommissioned light water nuclear power plant with more than 700 data measurement channels located throughout the containment. These tests, the E11 series, were designed to simulate conditions in a containment over long periods of time under scenarios that are not always considered during the design phase. The purpose of the tests was to clarify the concepts and procedures necessary for mitigation of these events. An added aspect of these tests is to allow verification and enhancement ofmore » computer simulation programs currently used for containment analysis. The CONTAIN servere reactor accident code is one such program developed by Sanida National Laboratory. The E11.4 test of the series included several unique events over a 56-h period. Ths fission product decay heat to the containment vessel from the primary system was simulated by a continuous external source of steam introduced into a lower compartment room. The actual loss-of-coolant accident (LOCA) was performed using the existing reactor vessel pressurized to 110 bar, which was allowed to blow down into the identical room as the external source. Later in the test an 85-15 vol % helium-hydrogen gas mixture was introduced into the containment to simulate the oxidation reaction of Zircaloy cladding, which can occur during the LOCA. The gas mixture had been added at two time frames during the test and with varying mass flow rates. Twenty-four gas measuring instruments were located throughout the containment building to assess the distribution of the hydrogen gas as well as the effect of noncondensable gases on the heat transfer to existing structures.« less