ML18136A457

From kanterella
Jump to navigation Jump to search
Forwards Response to IE Bulletin 79-28 Re Possible Malfunction of Namco Limit Switches.All Namco Limit Switches in safety-related Equipment Have Had Top Gaskets Replaced in Accordance W/Manufacturer Recommendations
ML18136A457
Person / Time
Site: Surry, North Anna  Dominion icon.png
Issue date: 01/09/1980
From: Stallings C
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
IEB-79-28, NUDOCS 8002040228
Download: ML18136A457 (3)


Text

e VIRGINIA ELECTRIC AND POWER COMPANY RrcHMON'D,Vl:ROl:N.IA 2326.l.

January 9, 1980 Mr. James P. O'Reilly, Director ll 38A/ 120 779 Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 50-280 Region II 50-281 101 Marietta Street, Suite 3100 50-338 Atlanta, Georgia 30303 ~- 50-339 License Nos: DP -32 DPR-37 NPF-4 Fermi t No. CPPR-78 Subj~ct: IE Bulletin 79-28

Dear Mr. 0 'Reilly:

This is in response to. IE Bulletin 79-28, 11 Possible Malfunction of Namco Model EA180 Lim:1.t Switches at *Elevated Temperatures". Our responses for North Anna Power Station and Surry Power Station are attached.

Very truly yours, z;.}t;t?. 0?au;np C. M. Stallings Vice President-Power Supply and Production Operations Attachment

. cc: Director, Office of Inspection and Enforcement Division of Reactor Operations Inspection

u. S. Nuclear Regulatory Comm:lssion Washin*gton, D. C. 20555
  • North Anna Power Station e

Attachment, page 1 Response to IE Bulletin 79-28 Possible Malfunction of Namco Model EA 180 Limit Switches at Elevated Temperatures

1. Determine if your facility has installed or plans to install Namco EA180 switches in any safety-related equipment located inside or outside con-tainment, including valve position indicating circuitry related to con-tainment isolation valves.

Response

We have reviewed the subject bulletin and, based on the results of our equip-ment review, we have determined that the installed switches for both units do not fall between date codes 02-79 and 08-79.

2. If such switches are identified, examine the four digit number stamped on the conduit boss of the switch housing. If this number falls between 02-79 and 08-79, replace the top gasket of the switch in accordance with the manufacturer's recommendations provided in the enclosed letter.

Response

New replacement switches which were received during that period, although not necessarily date coded between 02-79 through 08-79, were modified by replacing the top gasket of the switch in accordance with the manufacturer's recommendations.

3. Submit your plans and programs, including schedules for corrective action, regarding your findings in response to Items 1 and 2 above.

Response

Since we have determined that all NAMCO Model EA180 switches in safety-related equipment located inside or outside containment, including valve position indication circuitry related to containment isolation valves, 11hlch were received between 02-79 and 08-79 have had the top gasket of the switch replaced in accordance with the manufact.urer. 's recornrnenda tions, we believe no further action is required. This applies to both Unit Nos.

1 and 2.

e Attachment, page 2 Surry Power Station Response to IE Bulletin 79-28 Possible Malfunction of Namco Model EA180 Limit Switches at Elevated Temperatures

1. Determine if your facility has installed or plans to install Namco EA180 switches in any safety-related equipment located inside or outside con-tainment, including valve position indicating circuitry related to containment isolation valves.

Response

Surry Power Station presently has six Namco EA180 model limit switches on site but not installed in any safety-related equipment.

2. If such switches are identified, examine the four digit number stamped on the conduit boss of the switch housing. If this number falls between 02-79 and 08-79, replace the top gasket of the switch in accordance with the manufacturer's recommendations provided in the enclosed letter.

Response

The six switches do have four digit numbers on the housing which fall between 02-79 and 08-79. The top gaskets of the switches have been replaced with nevr gaskets in accordance with the manufacturer's recommendations.

3. Submit your plans and programs, including schedules for corrective action regarding your findings in response to items 1 and 2 above.

Response

It is anticipated that the corrective actions already taken are sufficient.