ML19208A958
| ML19208A958 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 09/11/1979 |
| From: | Kelly R GEORGIA POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7909180353 | |
| Download: ML19208A958 (2) | |
Text
J Georgia Power Company 230 Peachtree Street Post Office Bcx 4545 Attanta. Georg a 30302 Tefeenone 404 522-6060 m
R. J. Kelly Georoia Power vce Pres. dent and General Manager O
Pondr Generation tre sourwm eectnc nstem September 11, 1979 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, D.C.
20555 NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EDWIN 1. HATCH NUCLEAR PLANT, UNITS 1, 2 TARGET ROCK SAFETY / RELIEF VALVES GENTLDIEN:
The following information is provided pursuant to your request of July 16, 1979, concerning Target Rock Safety / Relief Valves.
It should be noted that safety / relief valves of a two-stage topworks design are currently installed at both Plant Hatch units:
QUESTION 1:
khat is the status of each of the Target Rock safety / relief valves at your plants; i.e:
a)
Are they in their original design configuration?
b)
What is the existing simmer margin?
c)
What modifications have you implemented to improve reliability?
d)
On what date were these nodifications made?
RESPONSE 1:
a)
Unit 1 - The originally installed three-stage topworks design valves were replaced with improved two-stage topworks design valves in the spring of 1978 (reference C. F. Whitmer's letter of February 10, 1978, to the Director of Nuclear Reactor Regulation).
Unit 2 - The originally installed two-stage topworks design valves remain in place.
360078 b)
The existing simmer margins are 75 psig and 85 psig for Units 1 and 2, respectively, c)
The angle of the pilot valve seat has been reduced and the blowdown orifice modified for backpressure considerations.
@ g d)
The modifications noted in (le) above were made in July 1979 t
for Unit 1 and April 1979 for Unit 2.
l V
$909 t 8 0 383 gC
k Georgia Power n QUESTION 2:
What maintenance and testing do you routinely perform on these valves and how often is it performed?
RESPONSE 2:
Valve operability checks are performed after valve maintenanec; bench testing is performed in accordance with the Technical Specifications and ASME Section XI, Part IWV3510, as a minimum on a periodic basis.
CUESTION 3:
What additional modifications and/or maintenance do you plan to implement in the future?
RESPONSE 3:
With the improved two-stage topworks design valves in place, no additional modifications or maintenance actions beyond the requirements of the Technical Specifications or accepted recommendations of the vendors are planned unless and until operational experience shows it to be necessary.
OUESTION 4:
On what date will the modifications and/or maintenance in item 3 be implemented?
RESPONSE 4:
Not applicable.
Should you require further information or clarification, please contact this office.
Yours very truly, R. J. Kelly WEB /mt xc:
- k. A. Thomas G. F. Trowbridge, Esquire 3600'29