ML20040B854

Final Deficiency Rept Re Discrepancy Between Standby Gas Treatment Sys & Peid Drawings,Initially Reported on 811203. Field Change Notices Issued to Revise Drawings to Reflect as-built Configuration

ML20040B854
Person / Time
Site:	Grand Gulf
Issue date:	01/08/1982
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-82-10, NUDOCS 8201260478
Download: ML20040B854 (4)

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MISSISSIPPhPOWER:& LIGHT COMPANY

' 'MiIpin'g. B O~ild . Mis sis s ippi P. O . BOX 1640, JACKSON, MISSISSIPPI 39205 J AMES P. McGAUGHY, JR ASSisf ANi vrCE PAE$iDENT January 8, 1982 Of fice of Inspection & Enforcement p U. S. Nuclear Regulatory Commission '

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Region II 101 Marietta Street, N.W.

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i Suite 3100 '

Atlanta, Georgia 30303 '

Attention: Mr. J. P. O'Reilly, Regional Administrator /

i Dea r Mr. O'Reilly:

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 l

I File 0260/15525/15526 PRD-81/51, Final Report, Incorrect SGTS Installation Drawings AECM-82/10 On December 3, 1981, Mississippi Power & Light Company notified Mr. F.

Cantrell, of your of fice, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns the Standby Gas Treatment System (SGTS) installation drawings which do not agree with the piping and installation diagram (P&ID) drawings.

We have completed our investigation of this matter and have determined that this deficiency is reportable under the provisions of 10CFR50.55(e) for MP&L but not under the provisions of 10CFR21.

Attached is our Final Report on this matter. The report was originally due on January 4, 1982; however, an extension was requested f rom and granted by Mr. R. Butcher, of your office, on that date.

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Mr. J. P. O'Reilly AECM-82/10 NRC Page 2 cc: Mr. N. L. Stampley Mr. R. B. McGehee Mr. T. B. Conner Mr. Richard C. DeYoung, Director Of fice of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 llattiesburg, MS 394Gi l

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Attachment to AECM-82/10 Page 1 of 2 FINAL REPORT FOR PRD-81/51 I. Description of Deficiency Installation drawings (ductwork layout) did not agree with Piping and Instru-mentation Diagram (P&ID) drawings, which resulted in the following deficiencies:

A. Standby Cas Treatment System (SGTS) ductwork physicalization did not follow the system P& ids. Intake for the SGTS "A" charcoal filter train was connected to the "B" recirculating fan ductwork, and the "B" charcoal filter train was connected to the "A" recirculating fan ductwork at elevation 228.

B. Dampers in the recirculating fan inlet ducts (SGTS) from the Enclosure Butiding were reversed in the physicalization drawings. An "A" dampe r was shown connected to the "B" recirculating fan ductwork, and a "B" damper was connected to the "A" recirculating fan ductwork.

C. The intake of the SGTS System "A" was tied into the Enclosure Building "B" recirculating fan; and the intake of the SGTS System "B" was tied into the Enclosure Building "A" recirculating f an at elevation 166.

D. Two isokinetic probes were transposed in their respective locations.

E. The plant system affected was the Standby Gas Treatment (T48) System.

Other systems tested did not identify this problem nor were they affected.

F. The deficiency is applicable to Unit 1.

G. We have determined that the deficiencies noted in A-C above are report-able under 10CFR50.55(e). The equipment noted in D above is not safety-related and therefore is not reportable. The deficiency does not apply to the NSSS vendor.

H. It should be underatood that although the deficiencies are technically reportable under the current reporting criteria of 10CFR50.55(e), the deficiencies could not have remained undetected once the SGIS underwent our testing program.

II. Analysis of Safety Implications in that credit cannot be taken for the fact that the deficiency could not have gone undetected we must conclude the deficiency could have adversely affected safety had it remained uncorrected.

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0 D Attachment to AECM-82/10 Page 2 of 2 A. Had the deficiency remained uncorrected, the possibility exists that during and after an accident, the Standby Gas Treatment System could have failed to perform its intended safety function of maintaining a 1/4 inch negative pressure in the SGTS boundary region. The following examples provide more details:

1. Improper ductwork physicalization would have resulted in low or no j flow at the SGTS fans. The combined operation of the SGTS trains, if j allowed to continue, would have achieved the intended function of the SGTS; however, loss of power from any one of the engineered safety busses or failure of any of the SGTS fans to operate, would cause the system to fail to perform its intended function.

2. This condition could also cause a positive pressure in the Enclosure l Building and leakage of untreated Auxiliary Building air to the outside via the Enclosure Building. However, the Auxiliary Building boundary could still have been maintained at negative pressure.

3. A mininum mixing ratio of Enclosure Building to Auxiliary Building air of 8:1 could not have been maintained.

B. The deficiency is not reportable under 10CFR21 since the af fected system has not been turned over to MP&L.

III. Corrective Actions Taken A. Revisions to the installation drawings failed to conform to the design drawing (P&lD). The extent of the condition has been determ'.Jed to be limited to System T48.

B. The af fected ducts were routed to the proper locations af ter deleting the Train "A" and Train "B" interconnections. The affected dampers aere also retagged and wired accordingly.

C. The described actions have been documented and dispositioned on our Constructor's Nonconformance Reports. This action included the issuance of Field Change Notices to revise drawings to reflect the necessary corrective action taken and the as-built configuration. All field modification is complete including revisions to appropriate drawings.

D. To preclude recurrence, designers have been instructed, through our Constructor's discipline engineering group supervisor, that all changes, including those made for physical reason's such as interface, must be checked for agreement with the P&ID. When a duct or pipe is rerouted, a check must be made to assure the system function remains the same as originally designed.

E. Corrective action has been completed.

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