This document provides guidance in the implementation of external events modeling in extended L2 PSA and is a complement of the ASAMPSA2 guidelines in this area. The conclusions of the ASAMPSA_E end-users survey and of technical meetings of WP10, WP21, WP22, and WP30 at Vienna University in September 2014 which are relevant for L2 PSA have been reflected in the content of the present document and are being taken into account as much as it is possible with the current status of knowledge.
Change history 3
List of diffusion 4
Summary 6
ASAMPSA_E Partners 7
Table of content 8
List of Tables 9
List of Figures 10
Glossary 11
1 Introduction 12
1.1 External events under consideration 12
1.2 Impact of external events on L2 PSA issues 13
2 External events specific issue impacting L2 PSA 13
2.1 Definition of Plant Damage States (PDS) 13
2.2 Containment Analysis, Phenomena and Source Terms 16
2.3 Human reliability analysis 19
2.4 Event tree modelling 22
2.5 Quantification of Event trees 23
2.6 Defence-In-Depth under external events loads 24
2.7 Analysis and presentation of results 25
2.8 Issues involving multi units sites 29
3 Compliance with end-user’s needs 35
4 Conclusions 36
5 Recommendations 37
6 List of references 38
7 Appendix 41
7.1 Appendix 1 - Example of an on-going seismic fragility analysis at IRSN (main steam line of a PWR) 41
7.2 Appendix 2 - Compliance of the report with the PSA End-Users Needs 44
ACWS
|
Auxiliary Cooling Water System
|
AESJ
|
Atomic Energy Society of Japan
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APET
|
Accident Progression Event Tree
|
BWR
|
Boiling Water Reactor
|
DiD
|
Defence in Depth
|
CCF
|
Common Cause Failure
|
CD
|
Core Damage
|
CDF
|
Core Damage Frequency
|
CDS
|
Core Damage State
|
CRT
|
Common Risk Target
|
ENSI
|
Eidgenössisches Nuklearsicherheitsinspektorat
(Swiss Federal Nuclear Safety Inspectorate)
|
EOP
|
Emergency Operating Procedure
|
FCI
|
Fuel Coolant Interaction
|
HRA
|
Human reliability analysis
|
L1
|
Level 1
|
L2
|
Level 2
|
MCCI
|
Molten Core Concrete Interaction
|
MCS
|
Minimal Cut-Set
|
PDS
|
Plant Damage State
|
PSA
|
Probabilistic Safety Analysis
|
RCS
|
Reactor Coolant System
|
SAM
|
Severe Accident Management
|
SAMG
|
Severe Accident Management Guidelines
|
SFP
|
Spent Fuel Pool
|
SSC
|
Structures, Systems and Components
|