ML20154R189

Responds to Generic Ltr 88-05, Boric Acid Corrosion of Carbon Steel Reactor Pressure Boundary Components in PWR Plants. Util Has Program to Identify,Evaluate & Correct Leaks in Sys Containing Boric Acid

ML20154R189
Person / Time
Site:	Farley
Issue date:	05/31/1988
From:	Mcdonald R ALABAMA POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
GL-88-05, GL-88-5, NUDOCS 8806070229
Download: ML20154R189 (4)

Text

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, Alaborrfa f'ower Company 600 North 18th Street

' Post offce Box 2641 Birmingham, Alabama 352914400 Telephone 205 250-1835 u

R. P. Mc Donald ggljgyg gyg Senior Vice President the sotthem ekctic systern 10CFR50.54 May 31, 1988 Docket Nos. 50-348 50-364 U. S. Nuclear Regulatory Comission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:

Joseph M. Farley Nuclear Plant - Units 1 & 2 Rt:rsponse to NRC Generic Letter 88-05 NRC Generic Letter 88-05, "Boric Acid Corrosion Of Carbon Steel Reactor Pressure Boundary Components In PWR Plants," requests that Alabama Power company provide assurances that a program has been implemented. We program is to consist of systematic measures to ensure that boric acid corrosion does not lead to degradation of the assurance that the reactor coolant pressure boundary will have an extremely low probability of abnormal leakage, rapidly propagating failure, or gross rupture. This program should include the following:

(1) A determination of the principal locations where leaks that are smaller than the allowable technical specification limit can cause degradation of the primary pressure boundary by boric acid corrosion.

Particular consideration should be given to identifying those locations where conditions exist that could cause high concentrations of boric acid on pressure boundary surfaces.

l (2) Procedures for locating small coolant leaks (i.e., leakage rates at less than technical specification limits).

It is important to establish the potential path of the leaking coolant and the reactor pressure boundary components it is likely to contact. This information is important in determining the interaction between the leaking coolant and reactor coolant pressure boundary materials.

(3) Methods for conducting examinations and performing engineering evaluations to establish the impact on the reactor coolant pressure boundary when leakage is located. his should include procedures to preeptly gather the necessary information for an engineering evaluation before the removal of evidence of leakage, such as boric acid crystal buildup.

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(4) Corrective. actions to prevent recurrences of this type of corrosion.

his should include any modifications to be. introduced in the present' design or operating procedures of the plant that (a) reduce the i

probability of primary coolant leaks at the locations where they may cause corrosion damage e.nd (b) entail the use of suitable corrosion resistant materials or the application of protective coatings / claddings.

Alabama' Power Company has a program to identify, evaluate and correct leaks in systems containing boric acid his program. consists of, as appropriate, 7

j inspections, evaluations, repairs, reviewing industry experiences and corrective actions.

A boric acid leak anywhere in the containment could cause degradation of the Reactor Coolant System pressure boundary if the leakage was allowed to.

accumulate on carbon steel components.

In general, areas subject to l

leakage include:

Welds Reactor vessel head penetration canopy seal welds i

Full penetration welds on Class 1 and 2 components (where j

leaks could cause degradation to carbon ~ steel)

Pressurizer heater penetrations

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Mechanical Connections j

Manway covers (Steara Generators and Pressurizer)

Reactor Coolant Pump main flange Reactor Coolant Pump seal housing Reactor Vessel flange i

Reactor Vessel conoseal bolting Valve body-to-bonnet connections j

Valve packing Flanged connections Resistance Temperature Detectors 4

• U. S. Nuclear Regulatory Comtnission May 31, 1988 Page 3 The Inservice Inspection Program (ISI) of Class 1 and 2 components includes volumetric, visual and/or surface examinations of welds and bolting. nis examination requires the identification and description of any leakage or evidence of leakage (boric acid crystal buildup) in the inspected portions of the systems.

Containment is inspected for leakage at the beginning of each refueling outage. %is inspection is performed at approximately normal operating temperature and pressure. A listing of potential leak sites is used as a guide in the inspection. Any leakage or evidence of leakage is documented and repairs are performed. The effects of the leakage are investigated but not documented unless the investigation determines that there has been degradation.

At the end of each refueling outage, an inspection is again performed at approximately normal operating temperature and pressure to identify any leakage.

If any leakage is found, it is repaired or the effects are investigated. his investigation is documented if degradation is projected.

If during the course of operation, personnel enter the containment for any reason, they are instructed to report any leakage or evidence of leakage that they may note.

If any is reported it is evaluated.

During operation, leakage is monitored as required by the technical specifications. Existing procedures allow for the ic'entification of leakage at rates less than the technical specification requirements.

Results are evaluated and, where abnormal leakage is suspected, investigations are performed to identify potential sources.

Some of the elements of the above program are not currently prescribed by-procedural guidance. However, procedures will be developed and/or modified to:

- Require the above described inspections to be performed and documented;

- Require the leakage path to be determined and documented;

- Provide guidelines for conducting examinations and evaluations to establish the effects of boric acid leakage on the reactor coolant i

system pressure boundary; i

- Ensure that information necessary for the evaluation is gathered prior to removal of the evidence of leakage, i.e., removal of the boric acid buildup;

- Include determination of whether design changes or modifications are necessary to mitigate recurrence.

%ese procedure modifications will be implemented by October 31, 1988.

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• U. S. Nuclear Regulatory Connission May 31, 1988 Page 4 If'you have any questions, please advise.

Respectfully submitted, ALABAMA POWER COMPANY AO, A

R. P. Mcdonald k

RPM / CDP:pln-8 cc:

Mr. L. B. Long Dr. J. N. Grace Mr. E. A. Reeves

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Mr. W. H. Bradford SWORN TO AND SUBSCRIBED BEFORE ME i

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, 1988

f. M0 Notary Publi p My comission Expires: 9-\\\\-8

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