ML20008E230

Second Interim Deficiency Rept Re Debris That Could Accumulate & Clog Heat Exchangers in Safety Related Sys.Util Reviewing Proposed Design Changes.Final Rept Will Be Submitted on 810306

ML20008E230
Person / Time
Site:	Grand Gulf
Issue date:	10/20/1980
From:	Mcgaughy J MINNESOTA POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, AECM-80-262, NUDOCS 8010240438
Download: ML20008E230 (2)

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NilSSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi Emendeang P. O. B O X 16 40. J A C K S O N. MIS SIS SIP PI 3 9 2 0 5 "5"$[Uc*e Eckr* October' 20, 1980 Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N.W.

Suite 3100 Atlanta, Georgia 30303 Attention: Mr. J. P. O'Reilly, Director

Dear Mr. O'Reilly:

SUBJECr: Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/32, Interim Report #2, Standby Service Water System Design Deficiency AECM-80/262

Reference:

AECM-80/153 On June 13, 1980, Mississippi Power & Light Company notified Mr. F. Cantrell of your office of a Potentially Reportable Defi-ciency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns debris in the Standby Service Water (SSW) basin being picked.up by the pumps and transferred into the system.

As previcusly reported, we have determined this condition to be reportable under 10CFR50.55(e). Our engineering review of cor-rective action is in progress. Details are described in the at-tached interim report. We expect to send you our final report on this matter by March 6, 1981.

Yours truly, Jn, f(A-fyJ.P.McGaughy,Jr.

R WDH:mt Attachment 0

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cc: Mr. N. L. Stampley Mr. Victor Stello, Directo#

Mr. R. B. McGehee Division of Inspection & Enforcement Mr. T. 3. Conner U. S. Nuclear Regulatory Cor: mission Washington, D.C. 20555 8010240 Y I 8 Member Middle South Utilities System

l INTERIM REPORT NO. 2 FOR PRD-80/32 l I. Description of the Deficiency The constructor discovered that during flush of the Standby Ser-vice Water (SSW) System, the pumps caused debris te he picked up and transferred into the SSW system. Investigata s revealed that the design permitted debris to enter the SSW basin from the surrounding area. Debris could potentially accumulate and clog heat exchangers in safety related systems serviced by the SSW system and/or restrict orifices in the SSW System piping which services safety related equipment. Examples of safety related systems serviced by the SSW system are the RHR heat exchangers, the HPCS, RER, & LPCS pumps bearing coolers, the HPCS Diesel Generator Cooler, and the Standby Diesel Generator Cooler. Should debris enter the system and clog the flow path of the cooling water, the heat exchang'ers could be rendered inoperable, thus leading to oil overheating, and, ultimately, to bearing and pump failure.

II. Proposed Resolution

• Mississippi Power & Light Company is working with the constructor to investigate and resolve this deficiency. The following steps are being taken in this investigation:

1. Evaluate the condition for affect on safety, assuming that it remains uncorrected throughout the expected lifetime of the plant. Determine reportability under 10CFR50.55(e) and 10CFR21.

2. Identify and perform corrective action.

3. Perform corrective actions to preclude recurrence.

III. Status of Proposed Resolution The safety analysis to determine reportability is complete. This item was determined reportable under 10CFR50.55(e). This design condition is related to the design of the GGNS only. All other Bechtel designed nuclear plants have a screening device on the suction of the SSW pumps.

Determination and implementation of remedial and corrective action is proceeding. MP&L engineering is reviewing proposed design changes.

IV. Reason for Delav in Final Report Corrective action has not been completed.

V. Final Report Date We expect to file our Final Report on this matter by March 6, 1981.

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