ML20113H445

Proposed Tech Spec Section 3.3.D.2.c,conforming to Equivalent NUREG-0452 Tech Spec,To Facilitate Removal of Loose Part in CWS

ML20113H445
Person / Time
Site:	Prairie Island
Issue date:	01/18/1985
From:	NORTHERN STATES POWER CO.
To:
Shared Package
ML20113H420	List: ML20113H418 ML20113H445
References
RTR-NUREG-0452, RTR-NUREG-452 TAC-56738, TAC-56739, NUDOCS 8501250151
Download: ML20113H445 (4)

Text

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Exhibit A Prairie Island Nuclear Generating Plant License Amendment Request Dated January 18, 1985 Evaluation of Proposed Changes to the Technical Specifications Appendix A of Operating License DPR-42 and DPR-60 Pursuant to 10 CFR Part 50, Sections 50.59 and 50.90 the holders of Operating Licenses DPR-42 and DPR-60 hereby propose the following change to Appendix A, Technical Specitics.tions:

COOLING WATER HEADER OPERABILITY b

Proposed Change Change "24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />" to "72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />" in paragraph TS 3.3.D.2.c as shown in j Exhibit B.

. Reason For Change f

, Technical Specification Section 3.3.D.2.c presently allows one of the two required cooling water headers to be out of service for a period not to exceed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Removal of a loose part located in Loop A of the Prairie Island Cooling Water System requires removing the inlet portion of cooling -

water Loop A from service for a period in excess of the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed by TS 3.3.D.2.c. Thus, removal of the loose part under the existing Technical Specification requirements would require the shutdown of both units.

Significant Hammeds Evaluation The Standard Technical Specification equivalent to TS 3.3.D.2.c (NUREG-0452, Section 3.7.4, Service Water System), allows one loop of cooling water to 4

be out of service for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> requirement in TS 3.3.D.2.c is overly conservative and restrictive and does not provide adequate flexibility for anything beyond minor system maintenance. Adoption of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limitation from the Standard Technical Specificatione should provide the additional flexibility necessary to maintain the system, while

, providing assurance that adequate cooling water will be available to the plant at all times. While this change may result in some increase in the consequences of a previously-analyzed accident, the results are clearly within the bounds of previous Commission guidance in that it conforms to the corresponding Standard Technical Specification.

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For these reasons, operation of the Prairie Island Nuclear Generating Plant in accordance with this proposed change will not:

(1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

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EXHIBIT B Prairie Island Nuclear Generating Plant '

License Amendment Request dated January 18, 1985 Proposed changes to the Technical Specifications of Appendix A of Operating Licenses DPR-42 and 60.

Exhibit B consists of revised pages of Appendix A Technical Specifications as listed below:

P,, agess TS.3.3-5A

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- TS.3.3-5A REV

a. One diesel-driven cooling water pump may be inoperable for a period not to exceed seven days (total for both diesel-driven cooling water pumps during any consecutive 30 day period) provided: .

(1) the operability of the other diesel-driven pump and its associated diesel generator are demonstrated immediately and at least once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereaf ter.

(2) the engineered safety features associated with the operable diesel-driven cooling water pump are operablo; and (3) both off-site power supply paths from the grid to tha 4Kv emergency buses are operable.

(4) two motor-driven cooling water pumps shall be operable,

b. One of the two required motor-driven cooling water pumps may be inoperable for a period not to exceed seven days provided:

(1) the operability of both diesel-driven cooling water pumps is demonstrated immediately and at least once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter.

c. One of the two required cooling water headers may be inoperable for a period not to exceed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided: ,

(1) the operability of the diesel-driven pump and the diesel generator associated with safety features on the operable header is demonstrated im:2ediately.

(2) the horizontal motor-driven pump associated with the operable header and the vertical motor-driven pump are operable.