Seismic qualification of equipment in operating nuclear power plants: Unresolved Safety Issue A-46

Technical Report · Sun Feb 01 04:00:00 EST 1987

OSTI ID:6876647

Chang, T Y

The margin of safety provided in existing nuclear power plant equipment to resist seismically induced loads and perform their intended safety functions may vary considerably, because of significant changes in design criteria and methods for the seismic qualification of equipment over the years. Therefore, the seismic qualification of equipment in operating plants must be reassessed to determine whether requalification is necessary. The objective of technical studies performed under the Task Action Plan A-46 was to establish an explicit set of guidelines and acceptance criteria to judge the adequacy of equipment under seismic loading at all operating plants, in lieu of requiring qualification to the current criteria that are applied to new plants. This report summarizes the work accomplished on USI A-46. In addition, the collection and review of seismic experience data and existing seismic test data are presented. Staff assessment of work accomplished under USI A-46 leads to the conclusion that the use of seismic experience data provides the most reasonable alternative to current qualification criteria. Consideration of seismic qualification by use of experience data was a specific task in USI A-46. Several other A-46 tasks serve to support the use of an experienced data base. The principal technical finding of USI A-46 is that seismic experience data, supplemented by existing seismic test data, applied in accordance with the guidelines developed, can be used to verify the seismic adequacy of mechanical and electrical equipment in operating nuclear plants. Explicit seismic qualification should be required only if seismic experience data or existing test data on similar components cannot be shown to apply.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (USA). Div. of Safety Review and Oversight
• OSTI ID: 6876647
• Report Number(s): NUREG-1030; ON: TI87900528
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
BLACKOUTS
DOCUMENT TYPES
EARTHQUAKES
GROUND MOTION
LOSS OF COOLANT
MOTION
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
OPERATION
POWER PLANTS
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR OPERATION
REACTOR SAFETY
REGULATIONS
REGULATORY GUIDES
SAFEGUARD REGULATIONS
SAFETY
SAFETY STANDARDS
SEISMIC EFFECTS
SEISMIC EVENTS
STANDARDS
THERMAL POWER PLANTS