Leak-before-break issue
Light water reactors (LWRs) must be designed to accomodate loss of coolant accidents (LOCAs) up to and including a double-ended guillotine break (DEGB) of the largest pipe in the reactor coolant system. Advanced fracture mechanics technology [the leak-before-break (LBB) approach] has been used to demonstrate that there is a very low probability of DEGB in the kinds of piping used in many LWRs. Consequently, some licensing requirements have been relaxed. The issue with respect to new production reactor (NPR) design requirements is whether the LBB approach can be applied to NPR design concepts and whether there is justification for eliminating DEGB as a design basis accident. This paper recommends the following concerning NPR design criteria: Allow LBB analysis as a basis for eliminating pipe whip restraints and other supports designed to mitigate the loads for postulated ruptures in primary system piping; Not allow LBB analysis to eliminate the DEGB LOCA as a design basis accident for the emergency cooling system; and, Not allow LBB analysis to limit the design-basis accident (peak pressure and temperature) for containment and environmental qualifications.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); ERC Environmental and Energy Services Co., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 10179155
- Report Number(s):
- LA-SUB-93-230; ON: DE93019302; TRN: 93:003141
- Resource Relation:
- Other Information: PBD: 5 May 1989
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of Pipe Size on the Leak-Before-Break Recommended Safety Margins in a Typical Pressurized Water Reactor
Applicability of leak-before-break criteria
Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
DESIGN BASIS ACCIDENTS
PROBABILITY
BWR TYPE REACTORS
LOSS OF COOLANT
PWR TYPE REACTORS
FRACTURE MECHANICS
LICENSING
PIPE WHIP
RESTRAINTS
SUPPORTS
220900
210100
210200
REACTOR SAFETY
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
BOILING WATER COOLED
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
NONBOILING WATER COOLED