ML20212G076
| ML20212G076 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 10/17/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20212G083 | List: |
| References | |
| NUDOCS 9711050237 | |
| Download: ML20212G076 (1) | |
Text
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2-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 notiftet' by CONVEX of an impending storm, high winds, and/or high water levels, lie 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 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 and secured well in advance of a hydrologic event that is predicted to produce 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 RGs 1.59 and 1.102 and the requirements of General Design Criterion 2, " Design Bases for Protection Against Natural Phenomena."
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 capability for cold shutdown and maintenance.
The RG further states that each component of the flood protection must be passive and in place, as it is to be used for flood protection, during normal plant operation.
RG 1.102 describes the types of flood protection acceptable to the NRC staff for the safety-related structures, systems, and components.
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 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 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 level reaching 14.5 feet MSL.
Therefore, the staff has determined, based on the above, that the proposed changes are acceptable.
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 officiel had no comments.
9711050237 971017 DR ADOCK 0 4y3 Enclosure
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