ML20055B665
| ML20055B665 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 07/15/1982 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8207220603 | |
| Download: ML20055B665 (3) | |
Text
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GPU Nuclear Ngg gf 100 Interpace Parkway Q
Parsippany, New Jersey 07054 201 263-6500 TELEX 136-482 Writer's Direct Dial Number:
July 15, 1982 Hr. Dennis M. Crutchfield, Chief Operating Reactors Branch #5 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Mr. Crutchfield:
Subj ect : Oyster Creek Nuclear Generating Station Docket No. 50-219 Containment Vent / Purge System In accordance with your letter of January 4,1982 and our letter of March 18, 1982 addressing the subject matter, please find attached responses to items 1,
3 and 5.
It is our intention to provide the information relative to the two remaining items by October 15, 1982.
As stated in our previous letter, the information presented will represent the subject system following its modification in the future.
If there are any questions concerning this matter, please contact Mr. J.
Knubel at (201) 299-2264.
Very truly yours, sL y
Pet r e er Vice President and Director - Oyster Creek 1r cc:
Ronald C. Haynes, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pa.
19406 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, N.J.
08731 8207220603 820715 PDR ADOCK 05000219 p
PDR hh GPU Nuclear is a part of the General Pubhc Utilities System W
Attachment Oyster Creek Containment Vent / Purge System 1.
During normal reactor operation, the drywell and torus are inerted with nitrogen to maintain the oxygen content below 5.0% by volume.
The inerted drywell atmosphere is maintained between 1.25 pai to 15 psi by providing nitrogen through 2"
make-up valves.
Excess nitrogen in the drywell is exhausted manually through 2" exhaust valves.
The vent-purge system containment isolation valves have been qualified to the guidelines in the commissions September 27, 1979 letter.
The actuator manufacturer recommends that the actuators be stroked at least oace per month to insure that the actuator seals remain flexible and do not leak.
Each valve can be operated independently, such that for surveillance cycling purposes, at least one of two redundant valves would be left closed.
For these reasons, a commitment to limit the use of the subject valves to a specified annual time is deemed unnecessary.
3 Our current technical specifications require local leak rate testing of all our vent and purge valves.
The valves are tested by pressurizing to 35 psig between isolation valves and measuring either the flow rate or proscure decay for leak tightness. This testing is performed once per refueling cycle.
Sinc e our vent and purge valves are to be replaced, our current and past surveillance and operating experience with the existing valves is not applicable.
However, due to the unique design of the replacement valves and the results of the manufacturer's leak tests, we ex pec t superior performance from the replacement valves in regard to leak tightness.
The new valves are torque seated and utilize a metal to metal sealing ar rangement.
Unlike the existing valves which are rubbe r-s eated, we expect no deterioration of the valve seat due to age or thermal cycling.
5 During normal reactor power operation, the d rywell and toru s are inerted with nitrogen to maintain the oxygen content below 5.0% by volume.
The drywell pressure is maintained within its opera ting limits via 2" make-up and exhaust valves.
Should a LOCA occur during nitrogen purging when the reactor is at power, the calculated accident doses are:
Exclusion Boundary LPS Thyroid Dose 59 23 (REM)
Whole Body 15 0.57 Dose (REM)
L
1 1
All the assumptions and methodology in the analysis were in accordance with R.G.
1.3 and SRP 6.2 4 The above results were based on the following assumptions:
a.
Reactor power level of 1930 MWT b.
Purging flow rate of 1000 CFM c.
Valve closure time of 5 seconds d.
No credit for decay of radioisotopes being released to the environment e.
SGTS filter efficiency of 99% for iodine f.
SGTS filter efficiency of Of for noble gases g.
Breathing rate of 3 47 x 10-4 cubic meters /see h.
Atmospheric diffusion factors of:
x ii at Exclusion Boundary = 1.1 x 10-4 sec/ cubic meters xii at LPS = 4.2 x 10-5 sec/ cubic meters
)
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