ML18332A246
| ML18332A246 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 04/24/1978 |
| From: | Mcduffie M Carolina Power & Light Co |
| To: | O'Reilly J NRC/RGN-II |
| References | |
| Download: ML18332A246 (1) | |
Text
.C KL tpa Power 8 Light Company
'~ April 24, 1978 Mr., James-P.
O'Reilly, Director U. S. Nuclear Regulatoxy Commission Region II, Suite 818 230 Peachtree
- Street, NW Atlanta, Georgia 30303 goo SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NOS. 1, 2, 3, AND 4 DOCKET NOS. 50-400, 50-401, 50-402, 50-403
RESPONSE
TO IE BULLETIN 78-04
Dear Mr. O'Reilly:
Inspection and Enforcement Bulletin No. 78-04 rortce~s st
..mrp>>n"rd limit switches on motor and air operated valves.
Certain stem mounted limit switches identified in the bulletin have not been qualified for LOCA conditions inside containment and could result in mispositioning of safety related valves following an accident.
Valves inside containment supplied by Ebasco Services, Inc., architect-engineer for the Shearon Harris Nuclear Power Plant (SHNPP),
have been surveyed for the use of these particular limit switches (NAMCO D2400X and EA-170-302 SNAP LOCK).
This investigation has shown that the D2400X limit switch had been specified for use on certain dampers in safety related air coolers inside containment and certain butter-fly valves that function as containment isolation valves.
- However, as used -with these dampers and valves, the stem mounted limit s~itches only provide valve and damper position indication.
They are not part. of the valve control circuitry and any failure due to lack of environmental qualification would not, by itself, cause mispositioning of these dampers or valves upon resetting of the safety injection signal or containment isolation signal.
Nevertheless, these D2400X stem mounted limit switches will either be appropriately qualified prior to operation of the SHNPP or be replaced with qualified substitutes.
All other stem mounted limit switches that are being supplied by valve
,vendors for use inside containment have been qualified for LOCA conditions.
This includes NAMCO Model EA-180 SNAP LOCK switches which the'endor states have been qualfied to IEEE Standards
- 323, 344, and 382.
Stem mounted limit switches inside containment supplied by Westinghouse will be qualified under their Supplemental Seismic and Environmental Qualification Program.
Yours very truly, M. A. McDuffie Senior Vice President Engineering 6 Construction MAM/gsm cc:
U.
S. Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D.
C.
20555 336 Fayettevitte Street
~ P. O. Box 1551
~ Raleigh, N. C. 27602