ML20196B949

Forwards Application for Amend to Licenses DPR-42 & DPR-60, Allowing Limited Inoperability of Bast Level Channels & Transfer Logic Channels to Provide for Required Testing & Maint of Associated Components

ML20196B949
Person / Time
Site:	Prairie Island
Issue date:	11/25/1998
From:	Sorensen J NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20196B954	List: ML20196B949 ML20196B957 ML20196B972
References
NUDOCS 9812010214
Download: ML20196B949 (3)

Text

S Northern States Power Company Pralrie Island Nuclear Generating Plant 1717 Wakonade Dr. East Welch, Minnesota 55089 November 25,1998 10 CFR 50.90 l

U S Nuclear Regulatory Commission Attn: Document Control Desk  ;

Washington, DC 20555 l l

PRAIRIE ISLAND NUCLEAR GENERATING PLANT  !

Docket Nos. 50-282 License Nos. DPR-42  !

50-306 DPR-60 License Amendment Request Dated November 25,1998 Boric Acid Storage Tank LevelInstrumentation j l

Attached is a request for a change to the Technical Specifications, Appendix A of the j Operating Licenses, for the Prairie Island Nuclear Generating Plant. Northem States Power Company submits this request in accordance with the provisions of 10CFR50.90.

Prairie Island Technical Specification 3.2.B.5 requires the operability of the Boric Acid Storage Tank (BAST) interlocks associated with the transfer of safety injection suction

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/'f from the BAST to the refueling water storage tank (R'NST). In addition, Technical Specification Table TS.4.1-1C, Functional Unit 7, requires the functional testing of the BAST transfer logic to the RWST on a monthly basis. In order to complete the testing //g required by the Technical Specifications, individual BAST level channels and transfer logic channels must be made inoperable. However, the Prairie Island Technical Specifications do not contain the allowances for the inoperability of BAST level channels or associated transfer logic channels to perform the required testing. This lack of allowance for channel inoperability also limits the performance of preventative and corrective maintenance on the system when above MODE 5.

This amendment request proposes changes to the Prairie Island Technical Specifications which would allow limited inoperability of boric acid storage tank (BAST) 9812010214 9s1125 PDR ADOCK 05000282'i P PDR i

, , Ucense Amendment Request dated Nov:mber 25,1998 Page 2 e,

level channels and transfer logic channels to provide for required testing and maintenance of the associated components.

The two Prairie Island units share three boric acid storage tanks. One tank is normally aligned to each unit during power operation and the third tank acts as a standby and is physically isolated. During power operation the tank acts as a source of highly concentrated boric acid to the chemical and volume control system. In addition, injection of this highly concentrated boric acid solution is necessary, per current analyses, to mitigate the consequences of a main steam line break accident. Additional j details on the system design are provided in Exhibit A.

It is possible to complete testing of the BAST to RWST transfer instrumentation without making level or logic channels associated with the inservice BASTS inoperable.

However, testing the instrumentation in that manner requires the physical re-alignment of the standby and in-service BASTS on each unit each month. As delineated in Exhibit A, this testing configuration has several disadvantages and increases the potential for a two unit shutdown resulting from the inability to complete the BAST instrumentation testing because of the inoperability of one of the three BASTS. For these reasons it is not considered a viable method for the long term testing of the BAST to RWST transfer instrumentation.

However, because the current Technical Specifications offer no alternative, NSP will utilize the re-alignment of the BASTS to complete the required testing while the NRC Staff reviews the proposed License Amendment Request. Because of the increased potential for a two unit shutdown and the disadvantages of the repeated BAST re-alignment, NSP respectfully requests that the NRC review and approve this License Amendment Request in an expedited manner.

Exhibit A contains a description of the proposed change, the reasons for requesting the change, the supporting safety evaluation, and the significant hazards determination.

Exhibit B contains current Prairie Island Technical Specification pages marked up to  !

show the proposed change. Exhibit C contains the revised Prairie Island Technical Specification pages incorporating the proposed change.

If you have any questions related to this license amendment request, please contact Gene Eckholt at 651-388-1121.

Joel P. Sorensen Plant Manager Prairie Island Nuclear Generating Plant i

, , License Amendment Request dated N v:mber 25,1998 Page 3 l

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c: Regional Administrator-Ill, NRC  !

NRR Project Manager, NRC ,

Senior Resident Inspector, NRC '

Kris Sanda, State of Minnesota '

J E Silberg  ;

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Attachments: 1 Affidavit Exhibit A, Evaluation of Proposed Changes to the Technical Specification Appendix A of Operation License DPR-42 and DPR-60.

Exhibit B, Marked Up Technical Specification Pages l I

Exhibit C, Revised Technical Specification Pages i

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