ML19294C258

Final Deficiency Rept on Bahnson Co safety-related Automatic & Gravity Ventilation Damper Setscrews.Setscrew Matl Too Hard,Causing Possible Slippage & Consequent Improper Blade Position.Fillet Welds Installed to Prevent Slippage

ML19294C258
Person / Time
Site:	Summer
Issue date:	02/12/1980
From:	Crews E SOUTH CAROLINA ELECTRIC & GAS CO.
To:
References
NUDOCS 8003070385
Download: ML19294C258 (2)

Text

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So ru CAnouNA ELECTRIC & GAS COMPANY N>st OFFsCC tos Poe COLUMs:A, SOUTH CAROLINA 29218 E.k carws Jm.

v.w e. ......... s.... c. c.....

c...........c...... February 12, 1980 Mr. James P. O'Reilly Office of Inspection and Enforce:ent f~A N 6 United States Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 3100 Atlanta, Georgia 30303

Subject:

V. C. Summer Nuclear Station Reportable Significant Deficiency -

Automatic and Gravity Dampers Nuclear Eng. File - 3.1051

Dear Pz. O'Reilly:

On February 8,1980 Mr. Tom Burdette of NRC Region II was notified of a reportable significant deficiency. Details of the problem are dis-cussed below:

1. Name of Reporting Individual Ronald B. Clary - P. O. Box 764 - Columbia, S. C. 29218

2. Identification of Basic Component Safety related automatic and gravity ventilation dampers.

3. Identification of Firm Supplying Component -

Bahnson, Industrial Air Quality Division, Box 10458, Winston Salem, North Carolina, 27108.

4. Nature of Defect Individual damper blades are connected to actuators and/or the damper frame by linkages. Setscrews are used to hold the blades, linkages and actuator arms in place. The problem discovered during startup testing is that the Bahnson design did not account for the hardness of a shaft and too hard a material was used. Under operating conditions setscrews holding the various blades, linkages and arms may come loose.

Therefore, the damper blades may assume an improper position.

Failure of the dampers to be in the correct position could possibly lead to excessive radiation exposures or affect the ability of the plant to safely shutdown.

30/7 SEE llo 8003071D

~6 3 5 4

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Mr. James P. O'Reilly United States Nuclea'r Regulatory Commission February 12, 1980 Page Two

5. Date Information of Defect was obtained The problem was first discovered on December 28, 1979. Evaluation of the scope of the problem, its affect on the safety of the plant and corrective action was co=pleted on February 8, 1980.

6. Number and Location of Defects sixty-four dampers in the fuel handling building ventilation system, control room ventilation system, relay room ventilation system, controlled access supply ventilation system, service water purphouse ventilation system, battery rotm ventilation system, instrument repair room ventilation system, computer room ventilation system and the diesel generator building ventilation system are involved.

7. Corrective Action Corrective action is being taken to provide fillet welds at several locations to prevent slipping. Also, EaSnson was notified for possible 10CFR Part 21 reporting purposes.

8. Advice This is a similar problem to the significant deficiency re-ported to the NRC on Dece:ber 18, 1979 regarding da=per/

actuator control ar= slippage.

Under the South Carolina Electric and Cas Cc pany program this defect which has been determined to be a substantial safety hazard defined by 10CFR Part 21 is being reported as s significant deficiency under 10CFR 50.55(e). Since corrective action has been determined and is in progress, this will be the final report on this item.

If any questions arise p1 ase let us know.

e uly yours, E. . rews, Jr.

REC:EHC:jv cc: Division of Inspection & Enforcement (Washington, D. C. )