ML20141H779
| ML20141H779 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 07/28/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20141H775 | List: |
| References | |
| NUDOCS 9708010176 | |
| Download: ML20141H779 (3) | |
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UNITED STATES g
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NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. 20066 4 001
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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 144 TO FACILITY OPERATING LICENSE NO. NPF-49 NORTHEAST NUCLEAR ENERGY COMPANY. ET AL.
l MILLSTONE NUCLEAR POWER STATION. UNIT NO. 3 DOCKET NO. 50-423
1.0 INTRODUCTION
l By letter dated April 28, 1997, the Northeast Nuclear Energy Company, et al.
j (the licensee), submitted a request for changes to the Millstone Nuclear Power Station, Unit No. 3 Technical Specifications (TS). TS 3.7.6 requires that i
flood protection be provided for the service water pump cubicles and L
components when the water level exceeds a specific value. The proposed amendment would (1) add the closing of the service water pump cubicle sump drain valves to the TS, (2) revise the wording of the action statement to be consistent with the limiting condition for operation, and (3) revise the i
associated Bases section.
2.0 EVALUATION In its letter dated April 28, 1997, the licensee stated that a modification was made to Millstone Unit 3 to install a drain line from the sump of each service water pump cubicle to the intake bay in order to provide a passive means of removing internal leakage from the cubicle and to improve internal flood protection for the cubicles. These valves are normally maintained in the open position and closure of the valves is required to provide protection to the pump cubicles from external flooding when sea level exceeds 13 feet mean sea level (MSL).
The licensee stated that the drain valves are category 1 valves that are periodically stroked under the plant maintenance program. The proposed change incorporates additional manual actions to provide external flood protection for the service water pump cubicles in the event water level exceeds 13 feet MSL by requiring that the cubicle sump drain valves be closed prior to the introduction of water from an external source.
The licensee further stated that the drain valves, which were installed as part of a plant modification, meet the intent of Regulatory Guide (RG) 1.59,
" Design Basis Floods for Nuclear Power Plants," and RG 1.102, " Flood Protection for Nuclear Power Plants" in a manner similar to that of the service water pump cubicle watertight doors.
In response to questions the NRC had regarding the Millstone Unit 3 Final Safety Analysis Report (FSAR), the 9708010176 970728 PDR ADOCK 05000423 P
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licensee, in a letter dated July 22, 1983, stated that the service water cubicle watertight doors would normally be left open.
The licensee further stated that when they are notified by CONVEX of an impending storm, high j
winds, and/or high water levels, the doors would be closed by operating procedures (i.e., administrative 1y controlled). The NRC staff, in the Safety Evaluation Report dated July 1984, stated that the licensee would be required j'
to ensure that the watertight doors into the service water cubicles are closed and secured during any hydrologic event that will result in water levels in excess of 14.5 feet MSL. The staff further stated that a TS or Emergency Operating Plan will be required to ensure that the watertight doors are closed i
and secured well in advance of a hydrologic event that is predicted to produce
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water levels in excess of 14.5 feet MSL. The staff concluded that based on its analyses, the plant design for probable maximum hurricane storm surge flooding and associated wave overtopping and runup meets the guidelines of i
RGs 1.59 and 1.102 and the requirements of General Design Criterion 2, " Design j
Bases for Protection Against Natural Phenomena."
i RG 1.59 requires that the conditions resulting from the worst site-related flood probable at a nuclear power plant with attendant wind-generated wave activity constitute the design basis flood conditions that safety-related structures, systems, and components must be designed to withstand and retain 1
capability for cold shutdown and maintenance. The RG further states that each j
component of the flood protection must be passive and in place, as it is to be
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used for flood protection, during normal plant operation.
RG 1.102 describes i
the types of flood protection acceptable to the NRC staff for the safety-related structures, systems, and components.
i The staff has reviewed the licensee's proposed change to add the manual action of shutting the service water pump cubicle sump drain valves to the existing j
required action to shut the watertight doors of both service water pump cubicles and determined that it is consistent with the Millstone Unit 3 design basis and is safe.
The staff's determination is based on that (1) the drain valves will be shut by procedure when the sea level reaches 13 feet MSL, (2) the Millstone Unit 3 TS already require manual action to be taken when the sea l
level reaches 13 feet MSL, and (3) the Millstone Unit 3 design and the licensee's manual actions meet the intent of RGs 1.52 and 1.102 in that flood protection will be provided for the service water cubicles prior to the sea i
level reaching 13 feet MSL.
Therefore, the staff has determined, based on the above, that the proposed j
changes are acceptable.
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3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Connecticut State official was notified of the proposed issuance of the amendment. The State official had no comments.
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4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR
'4 Part 20. The NRC staff has determined that the amendment involves.no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in ind.ividual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (62 FR 30636 dated June 4,1997). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
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5.0 CONCLUSION
The Commission has-concluded, based on the considerations discussed above, I
that:
(1) there is reasonable assurance that the health and safety of the i
public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
J. Andersen Date:
July 28, 1997 i
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