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Generic event trees and the treatment of dependencies and non-proceduralized actions in a low power and shutdown Probabilistic Risk Assessment

Conference ·
OSTI ID:10104927
;  [1];  [2];  [3]
  1. Science Applications International Corp., Albuquerque, NM (United States)
  2. Sandia National Labs., Albuquerque, NM (United States)
  3. Science and Engineering Associates, Inc., Albuquerque, NM (United States)

Sandia National Laboratories was tasked by the US Nuclear Regulatory Commission to perform a Probabilistic Risk Assessment (PRA) of a boiling water reactor (BWR) during low power and shutdown (LP&S) conditions. The plant chosen for the study was Grand Gulf Nuclear Station (GGNS), a BWR 6. In performing the analysis, it was found that in comparison with full-power PRAs, the low decay heat levels present during LP&S conditions result in a relatively large number of ways by which cooling can be provided to the core. In addition, because of the less stringent requirements imposed on system configurations possible is large and the availability of plant systems is more difficult to specify. These aspects of the LP&S environment led to the development and use of ``generic`` event trees in performing the analysis. The use of ``generic`` event trees, in turn, had a significant impact on the nature of the human reliability analysis (HRA) that was performed. This paper describes the development of the event trees for the LP&S PRA and important aspects of the resulting HRA.

Research Organization:
Sandia National Labs., Albuquerque, NM (United States)
Sponsoring Organization:
Nuclear Regulatory Commission, Washington, DC (United States)
DOE Contract Number:
AC04-94AL85000
OSTI ID:
10104927
Report Number(s):
SAND--93-2218C; CONF-940312--42; ON: DE94003233; BR: GB0103012
Country of Publication:
United States
Language:
English