Methods for handling of dependencies in HRA: Fortum case study

Markus Porthin

Research output: Book/ReportReportProfessional

Abstract

This report is a part of collaboration carried out in 2015 between a Nordic PSA Group (NPSAG) project and the SAFIR2018 research programme project PRAMEA (Probabilistic risk assessment method development and applications) with the objective to evaluate existing methods and develop supplementary guidance for the assessment of dependencies in Human Reliability Analysis (HRA). As part of the collaboration, Lloyd's Register Consulting performed a literature study on existing methods and guidance for assessment of dependencies in HRA and performed case studies in Sweden, financed by NPSAG. As part of PRAMEA two HRA dependency case studies were performed: One by VTT on Fortum's assessments and one by Risk Pilot on shutdown loss of cooling accidents (LOCA) in boiling water reactors (BWR). This case study performed by VTT examines the probabilistic assessments of dependency between multiple pre-initiator actions in Fortum's HRA as part of Loviisa 1 and 2 Probabilistic Safety Assessment (PSA). The chosen case example was the calibration error of two redundant thermostats due to a common cause failure (CCF) leading to loss of certain cooling systems in emergency situations due to no actuation of auxiliary air conditioning. Fortum's dependency model has been developed based on the Technique for Human Error Rate Prediction (THERP) method, from which it has been somewhat modified to better meet Fortum's needs. It can be concluded that the model gives similar results as THERP, seems reasonable and differentiates between different situations. The clearly defined questionnaire for determining the dependency level adds transparency and reproducibility to the method. It is also in reasonable agreement with NUREG-1792 Good Practices for Implementing HRA.
Original languageEnglish
PublisherVTT Technical Research Centre of Finland
Number of pages9
Publication statusPublished - 2015
MoE publication typeD4 Published development or research report or study

Publication series

NameResearch Report
PublisherVTT
VolumeVTT-R-05397-15

Fingerprint

Reliability analysis
Risk assessment
Thermostats
Boiling water reactors
Cooling systems
Air conditioning
Transparency
Accidents
Calibration
Cooling

Keywords

  • Human Reliability Analysis
  • HRA
  • dependencies
  • case study

Cite this

Porthin, M. (2015). Methods for handling of dependencies in HRA: Fortum case study. VTT Technical Research Centre of Finland. VTT Research Report, Vol.. VTT-R-05397-15
Porthin, Markus. / Methods for handling of dependencies in HRA: Fortum case study. VTT Technical Research Centre of Finland, 2015. 9 p. (VTT Research Report, Vol. VTT-R-05397-15).
@book{684b44738b5242f092b91c457dea936c,
title = "Methods for handling of dependencies in HRA: Fortum case study",
abstract = "This report is a part of collaboration carried out in 2015 between a Nordic PSA Group (NPSAG) project and the SAFIR2018 research programme project PRAMEA (Probabilistic risk assessment method development and applications) with the objective to evaluate existing methods and develop supplementary guidance for the assessment of dependencies in Human Reliability Analysis (HRA). As part of the collaboration, Lloyd's Register Consulting performed a literature study on existing methods and guidance for assessment of dependencies in HRA and performed case studies in Sweden, financed by NPSAG. As part of PRAMEA two HRA dependency case studies were performed: One by VTT on Fortum's assessments and one by Risk Pilot on shutdown loss of cooling accidents (LOCA) in boiling water reactors (BWR). This case study performed by VTT examines the probabilistic assessments of dependency between multiple pre-initiator actions in Fortum's HRA as part of Loviisa 1 and 2 Probabilistic Safety Assessment (PSA). The chosen case example was the calibration error of two redundant thermostats due to a common cause failure (CCF) leading to loss of certain cooling systems in emergency situations due to no actuation of auxiliary air conditioning. Fortum's dependency model has been developed based on the Technique for Human Error Rate Prediction (THERP) method, from which it has been somewhat modified to better meet Fortum's needs. It can be concluded that the model gives similar results as THERP, seems reasonable and differentiates between different situations. The clearly defined questionnaire for determining the dependency level adds transparency and reproducibility to the method. It is also in reasonable agreement with NUREG-1792 Good Practices for Implementing HRA.",
keywords = "Human Reliability Analysis, HRA, dependencies, case study",
author = "Markus Porthin",
note = "Project code: 101958",
year = "2015",
language = "English",
series = "Research Report",
publisher = "VTT Technical Research Centre of Finland",
address = "Finland",

}

Porthin, M 2015, Methods for handling of dependencies in HRA: Fortum case study. VTT Research Report, vol. VTT-R-05397-15, VTT Technical Research Centre of Finland.

Methods for handling of dependencies in HRA: Fortum case study. / Porthin, Markus.

VTT Technical Research Centre of Finland, 2015. 9 p. (VTT Research Report, Vol. VTT-R-05397-15).

Research output: Book/ReportReportProfessional

TY - BOOK

T1 - Methods for handling of dependencies in HRA: Fortum case study

AU - Porthin, Markus

N1 - Project code: 101958

PY - 2015

Y1 - 2015

N2 - This report is a part of collaboration carried out in 2015 between a Nordic PSA Group (NPSAG) project and the SAFIR2018 research programme project PRAMEA (Probabilistic risk assessment method development and applications) with the objective to evaluate existing methods and develop supplementary guidance for the assessment of dependencies in Human Reliability Analysis (HRA). As part of the collaboration, Lloyd's Register Consulting performed a literature study on existing methods and guidance for assessment of dependencies in HRA and performed case studies in Sweden, financed by NPSAG. As part of PRAMEA two HRA dependency case studies were performed: One by VTT on Fortum's assessments and one by Risk Pilot on shutdown loss of cooling accidents (LOCA) in boiling water reactors (BWR). This case study performed by VTT examines the probabilistic assessments of dependency between multiple pre-initiator actions in Fortum's HRA as part of Loviisa 1 and 2 Probabilistic Safety Assessment (PSA). The chosen case example was the calibration error of two redundant thermostats due to a common cause failure (CCF) leading to loss of certain cooling systems in emergency situations due to no actuation of auxiliary air conditioning. Fortum's dependency model has been developed based on the Technique for Human Error Rate Prediction (THERP) method, from which it has been somewhat modified to better meet Fortum's needs. It can be concluded that the model gives similar results as THERP, seems reasonable and differentiates between different situations. The clearly defined questionnaire for determining the dependency level adds transparency and reproducibility to the method. It is also in reasonable agreement with NUREG-1792 Good Practices for Implementing HRA.

AB - This report is a part of collaboration carried out in 2015 between a Nordic PSA Group (NPSAG) project and the SAFIR2018 research programme project PRAMEA (Probabilistic risk assessment method development and applications) with the objective to evaluate existing methods and develop supplementary guidance for the assessment of dependencies in Human Reliability Analysis (HRA). As part of the collaboration, Lloyd's Register Consulting performed a literature study on existing methods and guidance for assessment of dependencies in HRA and performed case studies in Sweden, financed by NPSAG. As part of PRAMEA two HRA dependency case studies were performed: One by VTT on Fortum's assessments and one by Risk Pilot on shutdown loss of cooling accidents (LOCA) in boiling water reactors (BWR). This case study performed by VTT examines the probabilistic assessments of dependency between multiple pre-initiator actions in Fortum's HRA as part of Loviisa 1 and 2 Probabilistic Safety Assessment (PSA). The chosen case example was the calibration error of two redundant thermostats due to a common cause failure (CCF) leading to loss of certain cooling systems in emergency situations due to no actuation of auxiliary air conditioning. Fortum's dependency model has been developed based on the Technique for Human Error Rate Prediction (THERP) method, from which it has been somewhat modified to better meet Fortum's needs. It can be concluded that the model gives similar results as THERP, seems reasonable and differentiates between different situations. The clearly defined questionnaire for determining the dependency level adds transparency and reproducibility to the method. It is also in reasonable agreement with NUREG-1792 Good Practices for Implementing HRA.

KW - Human Reliability Analysis

KW - HRA

KW - dependencies

KW - case study

M3 - Report

T3 - Research Report

BT - Methods for handling of dependencies in HRA: Fortum case study

PB - VTT Technical Research Centre of Finland

ER -

Porthin M. Methods for handling of dependencies in HRA: Fortum case study. VTT Technical Research Centre of Finland, 2015. 9 p. (VTT Research Report, Vol. VTT-R-05397-15).