Sensitivity, uncertainty, and importance analysis of a risk assessment

Journal Article · Fri May 01 00:00:00 EDT 1992 · Nuclear Technology; (United States)

OSTI ID:7116936

Andsten, R S ^[1]; Vaurio, J K ^[2]

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1. Imatran Voima Oy, PL 112, 01601 Vantaa (FI)
2. Imatran Voima Oy, PL 23 07901 (FI)

In this paper a number of supplementary studies and applications associated with probabilistic safety assessment (PSA) are described, including sensitivity and importance evaluations of failures, errors, systems, and groups of components. The main purpose is to illustrate the usefulness of a PSA for making decisions about safety improvements, training, allowed outage times, and test intervals. A useful measure of uncertainty importance is presented, and it points out areas needing development, such as reactor vessel aging phenomena, for reducing overall uncertainty. A time-dependent core damage frequency is also presented, illustrating the impact of testing scenarios and intervals. Tea methods and applications presented are based on the Level 1 PSA carried out for the internal initiating event of the Loviisa 1 nuclear power station. Steam generator leakages and associated operator actions are major contributors to the current core-damage frequency estimate of 2 {times}10{sup {minus}4}/yr. The results are used to improve the plant and procedures and to guide future improvements.

• OSTI ID: 7116936
• Journal Information: Nuclear Technology; (United States), Vol. 98:2; ISSN 0029-5450
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
LOVIISA-1 REACTOR
RISK ASSESSMENT
SENSITIVITY
AGING
DAMAGE
ERRORS
FAILURES
LEAKS
OUTAGES
PROBABILITY
REACTOR CORES
REACTOR VESSELS
STEAM GENERATORS
TESTING
TIME DEPENDENCE
UNCERTAINTY PRINCIPLE
BOILERS
CONTAINERS
ENRICHED URANIUM REACTORS
POWER REACTORS
PWR TYPE REACTORS
REACTOR COMPONENTS
REACTORS
THERMAL REACTORS
VAPOR GENERATORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
WWER TYPE REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
210200 - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled