skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Theoretical description of methodology in PHASER (Probabilistic hybrid analytical system evaluation routine)

Technical Report ·
DOI:https://doi.org/10.2172/199089· OSTI ID:199089

Probabilistic safety analyses (PSAs) frequently depend on fault tree and event tree models, using probabilities of `events` for inputs. Uncertainty or variability is sometimes included by assuming that the input probabilities vary independently and according to an assumed stochastic probability distribution modes. Evidence is accumulating that this methodology does not apply well to some situations, most significantly when the inputs contain a degree of subjectivity or are dependent. This report documents the current status of an investigation into methods for effectively incorporating subjectivity and dependence in PSAs and into the possibility of incorporating inputs that are partly subjective and partly stochastic. One important byproduct of this investigation was a computer routine that combines conventional PSA techniques with newly developed subjective techniques in a `hybrid` (subjective and conventional PSA) program. This program (PHASER) and a user`s manual are now available for beta use.

Research Organization:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC04-94AL85000
OSTI ID:
199089
Report Number(s):
SAND-96-0022; ON: DE96006072
Resource Relation:
Other Information: PBD: Jan 1996
Country of Publication:
United States
Language:
English