ML19219B290
| ML19219B290 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 03/02/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19219B289 | List: |
| References | |
| NUDOCS 8103110826 | |
| Download: ML19219B290 (2) | |
Text
ENCLOSURE O
S/FETY EVALUATION REPORT SUSCEPTIBILITY OF SAFETY-RELATED SYSTEMS TO FLOODING Fr?M FAILURE OF NON-CATEGORY l SYSTEMS FOR Mali 4E YANKEE ATOMIC POWER STATION 1.
INTRODUCTIOil By letter to the Maine Yankee Atomic Power Company (MYAPCO) dated September 27, 1972, we requested MYAPC0 to review the Maine Yankee Atomic Power Station to determine i.. nether the failure of any rion-Class 1 (seismic) equipment coulc' result in a condition such as flooding that might adversely affect the safe shutdown of the facility.
By letter to us dated October 20,1972, MYAPC0 responded to the original NRC request, furnishing information on postulated failure of the service water pumps and the circulating water pumps.
On June 7,1973, MYAPC0 subnitted additional detailed information to us which was the result of an extensive study conducted on the effects of piping failure av'.ernal to the Containment Building.
Proposed modi fi-cations to the system as outlined in this letter were not acceptable to us.
Revised inodification designs were outlined by MYAPC0 in their letter to us dated October 19, 1973.
We transmitted to MYAPC0 on December 17, 1974, a set of Guidelines for Protection from Flooding of Equipment Important to Safety. These guide-lines expanded on the scope of MYAPC0's original study and required further study of the flooding problem by MYAPCO.
MYAPC0 responded to our Guidelines by letter reports dated January 23, 1975 and February 19, 1975.
The various sources of potentia flooding identified by MYAPC0 and the affected safety-related equipment are discussed in the enclosed consultant's report.
II.
EVALUATION The enclosed technical evaluation report was prepared for us by our consultant, the Lawrence Livermore National Laboratory, as part of the Selected Operating Reactors Issues Program, FIN A0250.
8103 2 2 01r.tG
2-III.
CONCLUSIONS The consultant has reviewed the licensee's submittals for Maine Yonkee to determine if postulated failures of non-Category 1 (seismic) components could adversely affect the cperability of safety-related equipment.
We conclude that the licensee has demonstrated in their analysis that the Maine Yankee Atomic Power Station, excluding the Turbine Building, has the capacity and capability to manage and mitigate any single incident, such as flooding from a non-Class 1 system component or pipe, so that flooding will not prevent the safe shutdown of the plant and, is therefore, acceptable.
The licensee has further shown in the analysis for those areas addressed, that no single f ailure would result in common mode failure of redundant safety-related equipment, We recommend that the licer'see be required to submit an analysis of flooding of safety-related equipment in the Turbine Suilding resulting from failure of the circulating water piping or expansion joint in this area.
The receipt of this analysis is reonired to enable us to complete the evaluation for flooding of safety-r-La+ed equipment / systems at the Maine Yankee Atomic Power Station.