ML20009H410

Interim Deficiency Rept 1 Re Heating,Ventilation,Air Conditioning Automatic Air Dampers,First Reported on 800912. Evaluation of Known Safety Implications,Cause & Extent of Deficiency Completed.Next Rept Will Be Submitted by 811019

ML20009H410
Person / Time
Site:	Grand Gulf
Issue date:	07/29/1981
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-81-270, NUDOCS 8108100075
Download: ML20009H410 (5)

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MISSISSIPPI POWER '&'LlGHT: COMPANY Helping Build Mississippi P. O. B O X 16 4 0, J A C K S O N, MIS SI S SIP PI 3 9 2 0 5

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3 lv NUCLEAR PRODUCTION DEPARTMENT dh . j Of fice of Inspection & Enforcement July 29, 1981 U. S. Nuclear Regulatory Commission Region 11

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O 101 Marietta Street, N. W. 5 Suite 3100 Atlanta, Georgia 30303 s

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't UG 0 71986 4;g Ea, Attention: Mr. J. P. O'Reilly, Director Dear Mr. O'Reilly s

SUBJECT:

Grand Gulf Nu a t Units 1 and 2 Docket Nos. 50-416/417 File: 0260/15525/15526 PRD-80/57, Interim Report No. 1, HVAC Automatic Air Dampers AECM-81/270

Reference:

1) AECM-81/41, 1/23/81

2) AECM-80/254, 10/12/80 On September 12, 1980, Mississippi Power & Light Company notified Mr. M.

Hunt of your office of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns the i failure of tack welds on safety related automatic air dampers supplied by Pacific Air Products Company.

Our previous report stated mat remedial action would be to grind out the existing welds that failed and to reweld. However, our investigation has shown that the cause of the failure of the welds was that ASTM-A-108 12L14 steel, which is not suitable for welding, was utilized in the manufacture of the damper shaf ts. Therefore, other plans of corrective sction will be formulated and pursued.

Also, previous reports identified the af fected sys =n as the Safeguard Switchgear and Battery Rooms Ventilation System (X77). fhis should have been identified as Diesel Generator HVAC System (X77).

Working with our Constructor we have determined that this deficiency, had it remained uncorrected, could have af fected the safety of operations of the nuclear power plant and therefore is reportable under the provisions of 10CFR 50.55(e). It is not reportable per 10CFR21 as explained in our attached report.

Yours truly, j

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KDS:seb 8108100075 810729 Attachment DR ADOCK 05000 gf,f cc: See age 2 Member Middle South Utilities System I/ j

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Mr. J. P. O'Reilly AECM-270 NRC Page 2 cc

Mr. N. L. Stampley i Mr. . B. McGehee

, Mr. T. B. Conner Mr. Victor Stello, Director

Office of Inspection & Enforcement j U. S. Nuclear Regulatory Commission ,

j Washington, D. C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P.O. Box 1589 .

I j Hattiesburg, MS 39401

bec: Mr. F. L. Stampley Mr. J. N. Ward Mr. R. L. Scott Mr. R. S. Trickovic Mr. J. W. Yelverton Mr. L. F. I> ale Mr. C. K. McCoy Mr. T. H. Cloninger Mr. R. A. Ambrosino Mr. R. C. Fron Mr. G. B. Rogers Mr. M. R. Williams Mr. L. E. Ruhland Mr. D. L. Hunt Dr. D. C. Gibbs Mr. A. G. Wagner Mr. P. A. Taylor PRD File File

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Interim Report No. I for PRD-80/57

1. Description of the Deficiency l The tack welds connecting the shaf t to the damper blades on two safety reluted automatic air dempers failed during an attempt to open the blade. 1 Rue dampers are Q1X77F001 A-A and Q1X77F003-C in the Diesel Generator HVAC System (X77). These dampers nre supplied by Pacific Air Products Company. When failures were noted in these dampers, our Construc'c or undertook investigative action which identified other similar failures. The condition has now been determined to be generic in nature.

Systems affected in addition to the Diesel Generator HVAC (X77) are the Standby Service Water Building HVAC (Y47), Control Room HVAC (Z51), Safeguard Switchgear and Battery Room HVAC (Z77), and the Standby Gas Treatment System (T48). The deficiency is applicable to both Unit I, Unit II, and Common.

The failure of the welds could cauee the respective damper blades to be inoperative. Failure of the dampers associated with safety related equipment to fully open when required could result in temperatures above limits and loss of control room environmental control which could hazard safety related 4

equipment and operating personnel. Failure of the dampers to function according to design because < broken tack welds could cause malfunction of equipment in the Standby Ser vice Water System (P41), the Standby Diesel i

3enerators (P75), the High Pressure Core Spray Diesel Generator (P81), the Safeguard Switchgear and Battery Room, and the Control Room due to inadequate cooling. Inadequate environmental control in the control room could result due to loss of function of the Standby Fresh Air System and secondary containment integrity could be jeopardized by inadequate performance of the

Standby Gas Treatment System.

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Because of the above reasons, the failure of the tcck welds is reportable under tha provisions of 10CFR50.55(e). Some of the systems af fected have been j turned over to MP&L for acceptance, but the deficient items had been identified prior te turnover so this deficiency is not reportsble under the requirements of 10CFR21.

Investigation is continuing into the applicability of this deficiency to the NSSS vendor.

i II. Approach to Resolution of the Problem The cause of the tack weld failures is due to the inadequacy of the i material (ASTM-A-108 12L14 steel) utilized by the vendor for the damper shaf ts

and/or the use of inappropriate welding procedures for welding this type of material. The deficiency includes all safety related automatic air dampers where this type of material was used.

l Our Constructor has notified the vendor of the cause of the deficiency

and requested that they redesign the blade bracket to shaf t connection to eliminate the tack welding requirement in order to assure system reliability.

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III. Status of Proposed Resolution.

Evaluation of known safety implications and of cause and extent of the deficiency has been completed. Further corrective actions and actions to prevent recurrence will be formulated af ter receiving the vendor's response and new design for the dampers.

IV. Reason Why a Final Report Will Be Delayed Our Constructor is vaiting for the vendor to submit a new design for the I

blade bracket to shaft connection.

V. Date When Final Report Will Be Submitted Octobe r 19, 1981.

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