ML20154M112

Responds to Generic Ltr 88-05, Boric Acid Corrosion of Carbon Steel Reactor Pressure Boundary Components in PWR Plants. Program Document Describing Plant Policy to Identify & Correct RCS Leakage Being Prepared

ML20154M112
Person / Time
Site:	Prairie Island
Issue date:	05/25/1988
From:	Musolf D NORTHERN STATES POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), Office of Nuclear Reactor Regulation
References
GL-88-05, GL-88-5, NUDOCS 8806010177
Download: ML20154M112 (4)

Text

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/ Mnneapoks. Minnesota 55401 Telephone (612) 330 5500 May 25, 1988 Generic Letter 88-05 Director of Nuclear Reactor Regulat",-m s U S Nuclear Ragulatory Commiscion Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-41 50-306 DPR-60 Response to Generic Letter 88-05, Boric Acid Corrosion of Carbon Steel Reactor Pressure Boundary Components in PWR Plants The purpose of this letter is to respond to NRC Generic Letter 88-05 for the Prairie Island Nuclear Generating Plant.

Generic Letter 88-05 requested licensees of pressurized water reactors to "provide assurances that a program has been implemented consisting of systematic measures to ensure that boric acid corrosion does not lead to degradation of the assurance that the reactor cc olant pressure boundary will have an extremely low probability of abnormal leakage, rapidly propagating failure, or gross rupture." Policies and prac-tices are in place at Prairie Island to accomplish these goals. It has always been our policy to expeditiously repair all leaks in the Reactor Coolant System (RCS) to eliminate the potential for boric acid corrosion and radioactive contamination in the plant.

Our program for identification and correction of small RCS leakage has, until recently, been informal. In response to Generic Letter 88-05, a program document is being prepared which describes the Prairie Island policy with respect to identification and correction of small RCS leakage. The program document will contain the following ele-monts:

1. Potential Critical Leak Locations A list of principle locations where small leaks could cause corrosion of carbon steel RCS pressure boundary components will be included. This list will focus primarily on mechani-cal joints at locations adjacent to or over carbon steel ma-terials.

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2. Methods for Identifying and Locating e- 'l Leaks

- Plant surveillanco procedures and monitoring techniques will i be specified which enable the identification of leaks remotely orivisually during routine inspections of RCS leakage'inside l containment.

Remote leakage detaction methods have a sensitivity of approx.

imately 0.1 to 0.2 gpm. Visual inspections of accessible areas inside containment, which are used to locate and identi-fy potential corrosion concerns, are more sensitive.

3. Methods for Evaluation and Cleanup Leakage.whi.ch contacts carbon steel RCS components will be

r. ported to the System Engineer. The System Engineer will be the individual responsible for evaluating the operating im-pret, conducting an engineering evaluation of component dam-i ag , and specifying clean-up procedures and other corrective actions.

4. Actions to Prevent Recurrence (

E The System Engineer will be the individual responsible for initiating-necessary modifications to equipment, procedures, and specifications to reduce the potential for future boric acid leakage problems. Reduction in the probability of boric acid corrosion, including the use of corrosion resistant mate -

rials, will be the goal of these corrective actions.

The progsam for identification and correction of small RCS leakage will be incorpocated into the Prairie Island Operation Manual by June 15, 1988.

f We believe that th program we have described will provide assurance that the RCS will have cn extremely low probability of abncrmal leak-age, rapidly propagating failure, or gross rupture due to boric acid corrosion of earbon steel components.

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.g Director of NRR May 25, 1988 Northern States Power Company Page 3 Please contact us if you have any questions related to the information we have provided, e.

OYn David Musolf j Managcr Nuclear Support Services c: Regional Administrator, Region III, NRC NRC Sr Resident Inspector NRC Project Manager G Charnoff

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UNITED STATES NUCLEAR REGULATORY COMMISSION NORTilEh!; STATES POWER COMPANY PRAIRIE ISLAND NUCLEAR GENERATING PLANT DOCKET NOS. 50 282 50 306 RESPONSE TO GENERIC LETTER 88-05

. BORIC ACID CORROSION OF CARBON STEEL REACTOR PRESSURE BOUNDARY COMPONENTS IN PWR PLANTS Northern States Power Company, a Minnesota corporation, hereby submits information in response to Generic Letter 88-05.

.This submittal contains no restricted or other defense information.

NORTilERN STATES POWER COMPANY By D D Mw David Musolf h Manager Nuclear Support Services onthis8 day of htLtb ,/ M 8 before me a notary public in and for said County, p'6risonally appeared David Musolf, Manag-er buclear Support Services, and being first duly sworn acknowl-edged that he is authorized to execute this documert on behalf of Northern States Power Company, that he knows the contents there-of, and that to the best of his knowledge, information, and be-lief the statements made in it are true and that it is not inter-posed for delay.

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