ML20010F163

Final Deficiency Rept PRD-81/08 Re Installation of Standby Svc Water Pump,Initially Reported 810212.Item Reportable Under 10CFR50.55e But Not Under Part 21.Metal Will Be Machined from Outer Edge of Suction Bell on Four Pumps

ML20010F163
Person / Time
Site:	Grand Gulf
Issue date:	09/01/1981
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, AECM-81-318, NUDOCS 8109090445
Download: ML20010F163 (5)

Text

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T MISSISSIPPI POWER & LIGH.T COMPANY Helping Build Missis 3lppf e .

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September 1, 1981 , A 'l g

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' N, )' p-  % .g Office of Inspection & Enforcement ( j*'

• U. S. Nuclear Regulatory Commission ~

EP 0 91981> 8 Region II i:

101-Marietta Street, N.W. wn. manamme Suite 3100 ** gg Atlanta, Georgia 30303 N, Attention: Mr. J. P. O'P.eilly, Director '. j k,I

SUBJECT:

Grand Gulf Nocher Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-81/08, Final Report Installation of the Standby Service Water Pump AECM-81/318 On February 12, 1981, Mississippi Power 6 Light Company notified Mr. J.

Rausch, of your of fice, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns the installation of the Standby Service Water (SSW) Pump.

We have evaluated this condition and have determined that had it remained uncorrected, it could have affected the safety of operations of the nuclear power plant over the lifetime of the plant and is reportable under the pro-visions of 10CFR50.55(e). It is not reportable under 10CFR21 because the defic.tency was identified prio- to system turnover to MP&L.

Please note that our final report gives a different figure for the maximum calculated seismic moveme"* of the pump thac was given in previous reports. Our initial report used 7.8 inches wh! ' .as obtained from a telephone conversation. We have :oafirmed that the correct figure is 7.52 inches.

Yours truly, ll KDS:dr f ATTACHMENT cc: See page 2 l 0109090445 810901 PDR ADOCK 05000416 s PDR Member Middle South Utilities System

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- Mr. J. P. O'Reilly' - AECM-81/318 NRC Page 2 cc: Mr. N. L. Stampley;

• Mr. R. B. McGehee '

Mr. T. B. Conner.

Mr. Victor Stello, Director Of fice of' Inspeccion- & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. C. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Hattiesburg, MS.39401

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. C bbc: Mr. D. C. Lutken Mr. J. T.eatherman Dr. D. C. Gibbs Manager of BWR-6 Licensing Mr. J. N. Ward General Electric Company Mr. J. P. McCaughy, Jr. 175 Curtner Avenue Mr. J. D. Heaton San Jose, CA. 95125 Mr. R. Trickovic Mr. J. W. Yelverton Mr. L. F. Dale Mr. D. M. Houston Mr. C. K. McCoy U. S. Nuclear Regulatory Commission Mr. T. H. Cloninger Division of Licensing Mr. R. A. Ambrosino Washington, D. C. 20555 Mr. A. J. Iosue Mr. C. B. Rogers Mr. S. H. Hobbs Mr. J. Matore Mr. L. E. Ruhland U. S. Nuclear Regulatory Commission Mr. D. L. Hunt Division of Licensing Mr. A. C. Wagner Washington, D. C. 20555 Mr. P. A. Taylor PRD File File l

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[ Attachment'to AECM-81/318 P:ge 1 of 2 l

FINAL REPORT FOR PRD-81/08 I. Description of the Deficiency 1

Standby Service Water (SSW) Pumps A and B in both Unit I and Unit 2 have an ae- i

' built clearance between the pump bowl assembly and the sump wall of 5.0 inches

to 6.375 inches. The pump vendor, (Gould Pumps, Inc.) has . calculated _ the maxi-mum seismic movement to be 7.52 imches. Dueing a seismic event, the pump could l strike the SSW basin sump wall. l This deficiency affects the Standby Service Water System (P41) in both Unit 1 j and Unit 2. It is not applicable to the NSSS vendor. l

11. Analysis of Safety Implications The SSW system provides emergency cooling water for systems required for safe plant shutdown. These systems include the Standby Diusel Generator (P75) and safety-related HVAC Systems such as the Control Room HVAC (Z51) and Emergency Swit;chgear and Battery Room HVAC (Z77).

If the deficiency had remained uncorrected, there could have been an adverse ef fect on the safety of the nuclear power plact due to the possible failure of the SSW pumpa to perform their required safety function. Therefore, this deficiency is reportable under the provisions of 10CFR50.55(e). f"ince the af fected pumps had been identified prior to system turnover to MP&L, this deficien;> 18 not reportable under the provisions of 10CFR21.

III. _Correctf yo Actions Taken Two situations caused the deficiency. Fi r's t , the as-built condition does not exactly match our Constructor's design drawings. The pumps and the walls are not exactly on -location but are installed within construction tolerances. ' Also, the final design condition did not allow suf ficient clearance for the pump when the allowed construction tolerances were taken into account.

The original design clearance was 14 inches; however, the basin sump walls were installed of f location by approximately 6 to 6 /2 1 inches. . At the time this; con-dition was noted, in November,1975, the pump seismic movements were unknown. -

The new location of the basin walls was approved, which resulted in a design clearance of 7 1/2inches.

The seismic movements of the pump were known but were not taken into account during the fins' pump installation. This resulted in the approximately 5 to 6

. inch clearance now measured. for the four pumps.

The deficiency affects the four (4) Standby Service Water Pumps.

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. Attrchment to AECM-81/318 Feg2 2 of 2

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To correct the existing deficiency, metal will be machined from the outer edge of - the suction bell on each' of the four, pumps. The outside diameter will be reduced from 33.0 inches to 27.85 inches. This will provide sufficient clear-ance between the pumps and the adjacent concrete wall. For the pump which has the smallest clearance, a~6 inch x 6 inch x 0.1 inch patch of concrete must.be removed to provide the minimum calculated clearance required during a seismic event. All work has the approval of the vendor and is being done in accordance with his. drawings and instructions. We have determined that the modifications will have no detrimental effect on the operation of the pumps.

All corrective actions will be completed prior to fuel load. Since all SSW pumps at Grand Gulf Nuclear Station are af fected and will be modified as required. no actions are necessary to preclude recurrence.

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