ML19260C475
| ML19260C475 | |
| Person / Time | |
|---|---|
| Issue date: | 11/05/1979 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19260C474 | List: |
| References | |
| REF-GTECI-A-07, REF-GTECI-CO, TASK-A-07, TASK-A-7, TASK-OR NUDOCS 8001030636 | |
| Download: ML19260C475 (3) | |
Text
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[ Issued for Information]
7590-01 NUCLEAR REGULATORY COMMISSION
[ Docket Nos.: 50-219, 50-220, 50-237, 50-245, 50-249, 50-254, 50-259, 50-260, 50-263, 50-265, 50-271, 50-277, 50-278, 50-293, 50-296, 50-298, 50-321,50-324,50-325,50-331,50-333,50-341,50-354,50-355,50-366]
NOTICE OF ISSUANCE OF CRITERIA FOR THE MARK I CONTAINMENT LONG TERM PROGRAM The Nuclear Regulatory Corinission (NRC) staff has completed its review of the proposed suppression pool hydrodynamic load assessment criteria submitted by the General Electric Company on behalf of the licensees of Boiling Water Reac-tor (BWR) facilities with the Mark I pressure-suppression containment design.
As a result of this review, the staff has developed requirements by which the proposed criteria are to be implemented, and has issued these requirements to the affected utilities. This action represents a key milestone in the NRC's Generic Technical Activity A-7 (Mark I Containment Long Tem Program), which has been designated an " Unresolved Safety Issue" pursuant to Section 210 of the Energy Reorganization Act of 1974.
This generic study originated from concerns raised during the course of the NRC staff's review of test results for an advanced pressure-suppression contain-ment design (Mark III) and operating experience related to the pressure-suppression concept. The specific concern was the capability of the containment structure (i.e., suppression chamber) to withstand the effects of suppression pool hydrodynamic loads which had not been explicitly considered in the original design of the structure.
A short-term assessment was conducted, from which the NRC staff concluded that continued operation of the licensed BWR/ Mark I facilities would not jeopardize the public health and safety. However, the containment design safety margins were found to be less than that required by the Commission's regulations in General Design Criterion 50 of Appendix A to 10 CFR Part 50. Accordingly, exemp-tions from this requirement were issued to the licensed BWR/ Mark I facilities in March and April 1978, which pemitted continued plant operation until a more comprehensive long-term program could be completed.
The bases for these exemp-tions are described in NUREG-0408, " Mark I Containment Short Tem Program Safety Evaluation Report," dated December 1977. The purpose of the long-term program is to restore the original intended containment design safety margins.
The NRC staff's requirements for the long-term program define the generic metho-dology that is to be used by the affected utilities to design any additional structural and/or operational modifications which will restore the margins of safety, as determined by a plant-specific analysis.
These criteria were issued to the affected utilities in letters dated October 31, 1979, to commence the 1700 204 f
S 00103 0 dd 7590-01 implementation of this program.
Copies of the criteria are available for public inspection at the NRC Public Document Room, 1717 H Street, N.W.,
Washington, D.C. and the Commission's Local Public Document Room located in the vicinity of the affected nuclear power plants.
In addition, these criteria will be appended to the NRC staff's generic Safety Evaluation Re-port for the Mark I Containment Long Term Program, which is currently scheduled to be issued in December 1979.
For further information, contact Mr. Christopher Grimes, A-7 Task Manager, Division of Operating Reactors, U. S. Nuclear Regulatory Comission, Washington, D.C. 20555.
Dated at Bethesda, Maryland, this 31st day of October,1979.
OR THE NUCLEAR REGULATORY COMMISSION l
- n. Director e
1sen 5
Division of Operating Reactors Office of Nuclear Reactor Regulation 1700 205
SUMMARY
STATEMENT Notice The Nuclear Regulatory Commi.esion has issued the "NRC Acceptance Criteria for the Mark I Containment Long Term Program." This ac-tion represents a key milestone in the NRC staff's resolution of Generic Technical Activity A-7, which had been declared an "un-resolved safety issue" pursuant to Section 210 of the Energy Reorganization Act of'1974. The issuance of these criteria commence the implementation of this program. A generic Safety Evaluation Re-port for this program is scheduled to be issued in December 1979.
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