Experience from Level 2 Site Risk Analysis for Nordic Power Plants

Jan-Erik Holmberg, Stefan Authén, Ola Bäckström, He Xuhong, Salvatore Massaiu, Tero Tyrväinen

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Abstract

The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.
Original languageEnglish
Title of host publicationProceedings of the 29th European Safety and Reliability Conference
EditorsMichael Beer, Enrico Zio
Place of PublicationSingapore
PublisherResearch publishing services
Pages3790-3797
Number of pages8
ISBN (Electronic)978-981-11-2724-3
Publication statusPublished - Sep 2019
MoE publication typeA4 Article in a conference publication
Event29th European Safety and Reliability Conference - Welfenschloss, Hannover, Germany
Duration: 22 Sep 201926 Sep 2019
Conference number: 29
https://esrel2019.org/#/

Conference

Conference29th European Safety and Reliability Conference
Abbreviated titleESREL 2019
CountryGermany
CityHannover
Period22/09/1926/09/19
Internet address

Fingerprint

Risk analysis
Power plants
Accidents

Keywords

  • site risk analysis
  • nuclear power plant
  • level 2 PSA
  • probabilistic safety assessment
  • probabilistic risk analysis
  • multi-unit
  • severe accident
  • risk metrics
  • human reliability analysis

Cite this

Holmberg, J-E., Authén, S., Bäckström, O., Xuhong, H., Massaiu, S., & Tyrväinen, T. (2019). Experience from Level 2 Site Risk Analysis for Nordic Power Plants. In M. Beer, & E. Zio (Eds.), Proceedings of the 29th European Safety and Reliability Conference (pp. 3790-3797). [0276] Singapore: Research publishing services.
Holmberg, Jan-Erik ; Authén, Stefan ; Bäckström, Ola ; Xuhong, He ; Massaiu, Salvatore ; Tyrväinen, Tero. / Experience from Level 2 Site Risk Analysis for Nordic Power Plants. Proceedings of the 29th European Safety and Reliability Conference. editor / Michael Beer ; Enrico Zio. Singapore : Research publishing services, 2019. pp. 3790-3797
@inproceedings{59d67f889d33428786dc6190e14bf97a,
title = "Experience from Level 2 Site Risk Analysis for Nordic Power Plants",
abstract = "The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.",
keywords = "site risk analysis, nuclear power plant, level 2 PSA, probabilistic safety assessment, probabilistic risk analysis, multi-unit, severe accident, risk metrics, human reliability analysis",
author = "Jan-Erik Holmberg and Stefan Auth{\'e}n and Ola B{\"a}ckstr{\"o}m and He Xuhong and Salvatore Massaiu and Tero Tyrv{\"a}inen",
year = "2019",
month = "9",
language = "English",
pages = "3790--3797",
editor = "Michael Beer and Enrico Zio",
booktitle = "Proceedings of the 29th European Safety and Reliability Conference",
publisher = "Research publishing services",
address = "Singapore",

}

Holmberg, J-E, Authén, S, Bäckström, O, Xuhong, H, Massaiu, S & Tyrväinen, T 2019, Experience from Level 2 Site Risk Analysis for Nordic Power Plants. in M Beer & E Zio (eds), Proceedings of the 29th European Safety and Reliability Conference., 0276, Research publishing services, Singapore, pp. 3790-3797, 29th European Safety and Reliability Conference, Hannover, Germany, 22/09/19.

Experience from Level 2 Site Risk Analysis for Nordic Power Plants. / Holmberg, Jan-Erik; Authén, Stefan; Bäckström, Ola; Xuhong, He; Massaiu, Salvatore; Tyrväinen, Tero.

Proceedings of the 29th European Safety and Reliability Conference. ed. / Michael Beer; Enrico Zio. Singapore : Research publishing services, 2019. p. 3790-3797 0276.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

TY - GEN

T1 - Experience from Level 2 Site Risk Analysis for Nordic Power Plants

AU - Holmberg, Jan-Erik

AU - Authén, Stefan

AU - Bäckström, Ola

AU - Xuhong, He

AU - Massaiu, Salvatore

AU - Tyrväinen, Tero

PY - 2019/9

Y1 - 2019/9

N2 - The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.

AB - The objective with the SITRON (SITe Risk On Nuclear installations) project has been to search for practical approaches for Nordic utilities to assess the site level risk. This paper presents the findings from the performance of level 2 PSA, i.e., the assessment of radioactive release risk from multiple units. Qualitatively, a multi-unit level 1 and 2 PSA are similar in terms of identifying dependencies. Level 2 PSA may bring some additional dependencies that are not relevant for level 1 PSA. Quantitatively, the difference in the used risk metrics can have some practical implications. In level 1 PSA, risk metrics are the frequencies of combinations of core damages (one, two, ..., all units). In level 2 PSA, risk metric is the frequency of a certain release category (small, large, early, late), which is determined by the aggregated release rather than number of releases. The need to quantify various accident sequences is thus much dependent on the applied safety goal for level 2 PSA. Further, pilot studies indicate that inter-unit dependencies in level 2 safety functions have less influence on results than inter-unit dependencies in level 1 safety functions.

KW - site risk analysis

KW - nuclear power plant

KW - level 2 PSA

KW - probabilistic safety assessment

KW - probabilistic risk analysis

KW - multi-unit

KW - severe accident

KW - risk metrics

KW - human reliability analysis

M3 - Conference article in proceedings

SP - 3790

EP - 3797

BT - Proceedings of the 29th European Safety and Reliability Conference

A2 - Beer, Michael

A2 - Zio, Enrico

PB - Research publishing services

CY - Singapore

ER -

Holmberg J-E, Authén S, Bäckström O, Xuhong H, Massaiu S, Tyrväinen T. Experience from Level 2 Site Risk Analysis for Nordic Power Plants. In Beer M, Zio E, editors, Proceedings of the 29th European Safety and Reliability Conference. Singapore: Research publishing services. 2019. p. 3790-3797. 0276