Probabilistic safety goals. Phase 2 status report

Jan-Erik Holmberg, Kim Björkman, Jukka Rossi, Michael Knochenhauer, Xuhong He, Anders Persson, Gustavsson Helena

Research output: Book/ReportReportProfessional

Abstract

The second phase of the project, the outcome of which is described in this pro-ject report has mainly dealt with four issues: Consistency in the usage of safety goals, Criteria for assessment of results from PSA level 2, Overview of international safety goals and experiences from their use, Safety goals related to other man-made risks in society. Consistency in judgement over time has been perceived to be one of the main problems in the usage of safety goals. Safety goals defined in the 80ies were met in the beginning with PSA:s performed to the standards of that time, i.e., by PSA:s that were quite limited in scope and level of detail compared to today’s state of the art. This issue was investigated by performing a comparative review was performed of three generations of the same PSA, focusing on the impact from changes over time in component failure data, IE frequency, and modelling of the plant, including plant changes and changes in success criteria. It proved to be very time-consuming and in some cases next to impossible to correctly identify the basic causes for changes in PSA results. A multitude of different sub-causes turned out to combined and difficult to differentiate. Thus, rigorous book-keeping is needed in order to keep track of how and why PSA results change. This is es-pecially important in order to differentiate “real” differences due to plant changes and updated component and IE data from differences that are due to general PSA development (scope, level of detail, modelling issues).
Original languageEnglish
Number of pages46
Publication statusPublished - 2008
MoE publication typeD4 Published development or research report or study

Publication series

NameNKS
PublisherNordic nuclear safety research (NKS)
No.NKS-172
Volume172

Fingerprint

Safety

Keywords

  • Safety Goals
  • PSA
  • Safety Targets
  • ALARP
  • Decision criteria
  • Risk informed decision making

Cite this

Holmberg, J-E., Björkman, K., Rossi, J., Knochenhauer, M., He, X., Persson, A., & Helena, G. (2008). Probabilistic safety goals. Phase 2 status report. NKS, No. NKS-172, Vol.. 172
Holmberg, Jan-Erik ; Björkman, Kim ; Rossi, Jukka ; Knochenhauer, Michael ; He, Xuhong ; Persson, Anders ; Helena, Gustavsson. / Probabilistic safety goals. Phase 2 status report. 2008. 46 p. (NKS; No. NKS-172, Vol. 172).
@book{26c4134c66ba4f6288315503cd987413,
title = "Probabilistic safety goals. Phase 2 status report",
abstract = "The second phase of the project, the outcome of which is described in this pro-ject report has mainly dealt with four issues: Consistency in the usage of safety goals, Criteria for assessment of results from PSA level 2, Overview of international safety goals and experiences from their use, Safety goals related to other man-made risks in society. Consistency in judgement over time has been perceived to be one of the main problems in the usage of safety goals. Safety goals defined in the 80ies were met in the beginning with PSA:s performed to the standards of that time, i.e., by PSA:s that were quite limited in scope and level of detail compared to today’s state of the art. This issue was investigated by performing a comparative review was performed of three generations of the same PSA, focusing on the impact from changes over time in component failure data, IE frequency, and modelling of the plant, including plant changes and changes in success criteria. It proved to be very time-consuming and in some cases next to impossible to correctly identify the basic causes for changes in PSA results. A multitude of different sub-causes turned out to combined and difficult to differentiate. Thus, rigorous book-keeping is needed in order to keep track of how and why PSA results change. This is es-pecially important in order to differentiate “real” differences due to plant changes and updated component and IE data from differences that are due to general PSA development (scope, level of detail, modelling issues).",
keywords = "Safety Goals, PSA, Safety Targets, ALARP, Decision criteria, Risk informed decision making",
author = "Jan-Erik Holmberg and Kim Bj{\"o}rkman and Jukka Rossi and Michael Knochenhauer and Xuhong He and Anders Persson and Gustavsson Helena",
note = "Project code: 13107-1.1",
year = "2008",
language = "English",
isbn = "978-87-7893-238-9",
series = "NKS",
publisher = "Nordic nuclear safety research (NKS)",
number = "NKS-172",

}

Holmberg, J-E, Björkman, K, Rossi, J, Knochenhauer, M, He, X, Persson, A & Helena, G 2008, Probabilistic safety goals. Phase 2 status report. NKS, no. NKS-172, vol. 172.

Probabilistic safety goals. Phase 2 status report. / Holmberg, Jan-Erik; Björkman, Kim; Rossi, Jukka; Knochenhauer, Michael; He, Xuhong; Persson, Anders; Helena, Gustavsson.

2008. 46 p. (NKS; No. NKS-172, Vol. 172).

Research output: Book/ReportReportProfessional

TY - BOOK

T1 - Probabilistic safety goals. Phase 2 status report

AU - Holmberg, Jan-Erik

AU - Björkman, Kim

AU - Rossi, Jukka

AU - Knochenhauer, Michael

AU - He, Xuhong

AU - Persson, Anders

AU - Helena, Gustavsson

N1 - Project code: 13107-1.1

PY - 2008

Y1 - 2008

N2 - The second phase of the project, the outcome of which is described in this pro-ject report has mainly dealt with four issues: Consistency in the usage of safety goals, Criteria for assessment of results from PSA level 2, Overview of international safety goals and experiences from their use, Safety goals related to other man-made risks in society. Consistency in judgement over time has been perceived to be one of the main problems in the usage of safety goals. Safety goals defined in the 80ies were met in the beginning with PSA:s performed to the standards of that time, i.e., by PSA:s that were quite limited in scope and level of detail compared to today’s state of the art. This issue was investigated by performing a comparative review was performed of three generations of the same PSA, focusing on the impact from changes over time in component failure data, IE frequency, and modelling of the plant, including plant changes and changes in success criteria. It proved to be very time-consuming and in some cases next to impossible to correctly identify the basic causes for changes in PSA results. A multitude of different sub-causes turned out to combined and difficult to differentiate. Thus, rigorous book-keeping is needed in order to keep track of how and why PSA results change. This is es-pecially important in order to differentiate “real” differences due to plant changes and updated component and IE data from differences that are due to general PSA development (scope, level of detail, modelling issues).

AB - The second phase of the project, the outcome of which is described in this pro-ject report has mainly dealt with four issues: Consistency in the usage of safety goals, Criteria for assessment of results from PSA level 2, Overview of international safety goals and experiences from their use, Safety goals related to other man-made risks in society. Consistency in judgement over time has been perceived to be one of the main problems in the usage of safety goals. Safety goals defined in the 80ies were met in the beginning with PSA:s performed to the standards of that time, i.e., by PSA:s that were quite limited in scope and level of detail compared to today’s state of the art. This issue was investigated by performing a comparative review was performed of three generations of the same PSA, focusing on the impact from changes over time in component failure data, IE frequency, and modelling of the plant, including plant changes and changes in success criteria. It proved to be very time-consuming and in some cases next to impossible to correctly identify the basic causes for changes in PSA results. A multitude of different sub-causes turned out to combined and difficult to differentiate. Thus, rigorous book-keeping is needed in order to keep track of how and why PSA results change. This is es-pecially important in order to differentiate “real” differences due to plant changes and updated component and IE data from differences that are due to general PSA development (scope, level of detail, modelling issues).

KW - Safety Goals

KW - PSA

KW - Safety Targets

KW - ALARP

KW - Decision criteria

KW - Risk informed decision making

M3 - Report

SN - 978-87-7893-238-9

T3 - NKS

BT - Probabilistic safety goals. Phase 2 status report

ER -

Holmberg J-E, Björkman K, Rossi J, Knochenhauer M, He X, Persson A et al. Probabilistic safety goals. Phase 2 status report. 2008. 46 p. (NKS; No. NKS-172, Vol. 172).