Calculation of conditional reactor vessel fracture probabilities integrated over plant lifetime

Journal Article · · Nuclear Safety (Bimonthly Technical Progress Review); (United States)

OSTI ID:5078461

Gore, B F; Vo, T V ^[1]; Colburn, A J; Throm, E D

---

1. Pacific Northwest Lab., Washington, DC (United States)

This article and companion article (to be published in the next issue of Nuclear Safety) present a determination of the time-integrated lifetime risk as the result of low-temperature overpressure (LTOP) events for the 63 pressurized-water reactors (PWRs) operating at the end of 1986. This article presents the methodology and results of a determination of conditional reactor vessel fracture probabilities (given an LTOP event) integrated over plant lifetime. The companion article presents the expected frequency and severity of LTOP events, based on operating experience, and combines this information with the conditional vessel fracture probabilities and associated public risk estimates. The analysis determines the effects of continuing the present regulations and of the impositions of several proposed regulatory alternatives. The analysis addresses only overpressurization from a cold initial condition and hence does not address pressurized-thermal-shock events. The methodology and results presented in this article address the time-dependent effects of neutron embrittlement of reactor vessels. Plant-specific values of vessel chemistry and neutron fluence are used to determine conditional vessel fracture probability as a function of time and event severity for each of the 63 PWRs addressed. An approximate method is presented for integrating these results over plant lifetime, and results are presented for each of the PWRs. This analysis was performed by Pacific Northwest Laboratory for the US Nuclear Regulatory Commission to assist in resolution of Generic issue 94 (GI-94), Additional Low Temperature Protection.

• OSTI ID: 5078461
• Journal Information: Nuclear Safety (Bimonthly Technical Progress Review); (United States), Journal Name: Nuclear Safety (Bimonthly Technical Progress Review); (United States) Vol. 30:4; ISSN 0029-5604; ISSN NUSAA
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200 -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
CALCULATION METHODS
CONTAINERS
DATA
EMBRITTLEMENT
ENRICHED URANIUM REACTORS
FAILURES
FRACTURES
INFORMATION
NEUTRON FLUENCE
NUMERICAL DATA
OPERATION
POWER REACTORS
PRESSURE VESSELS
PRESSURIZATION
PROBABILITY
PWR TYPE REACTORS
RADIATION EFFECTS
REACTOR OPERATION
REACTOR START-UP
REACTORS
RISK ASSESSMENT
SERVICE LIFE
START-UP
THERMAL REACTORS
TIME DEPENDENCE
WATER COOLED REACTORS
WATER MODERATED REACTORS