ML20009G446
| ML20009G446 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/27/1981 |
| From: | Hukill H METROPOLITAN EDISON CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| L11-186, NUDOCS 8108040271 | |
| Download: ML20009G446 (1) | |
Text
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Metropolitan Edison Company II g
Post Office Box 480 Middletown, Pennsylvania 17057 Writer's Direct Dial Number July 27, 1981 LlL 186 Cifice of Nuclear Reactor Regulation N
Attn:
J. F. Stolz, Chief g
Operating Reactors Branch No. 4
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U. S. Nuclear Regulatory Commission tr'
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Washington, D.C.
20555
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9,s.
Dear Sir:
O Three Mile Island Nuclear Station, Unit 1 (TMI-1) g/
Operating License No. DPR-50 4/
Docket No. 50-289 A
Atmospheric Dump Valves Modification This letter is in response to your letter of April 28, 1981, concerning the automatic opening of the atmospheric dump valves upon loss of non-nuclear instrumentation power supply. Specifically, you requested we agree to follow the guidelines of one of the items listed in your letter referenced above.
Upon review of your letter, we have determined that there is another - alterna-tive to resolve this problem. We propose a daily reading of the meter on the manual J oader. This will confirm proper operation since any likely failure would cause a change in the meter position. We will implement the daily checks using normal administrative controls.
We consider this approach adequate in that:
1.
the valves have a relatively low relieving capacity and are provided with easily accessible manual isolation valves, 2.
the probability of demand on the backup system is low, and 3.
the probability of the backup system not performing is low since the probability of the I
.o P device failing in other than the denergized position is very low.
The combined probability of adverse consequences in light of items 2 and 3 above, make it excessive and unnecessary to do surveillance of the I/E device as suggested by your letter especially in light of the minimal consequences of failure of the backup system to function and the ability of the operator to isolate the dump valves if necessary.
Sincerely, 7
7k s
. D. I ki 1 Director, TMI-l HDil:DGM:vj f I
cc:
H. Silver L. Barrett B. J. Snyder D. DiIanni B. H. Grier Qg 0 8109040271 810727 'etropohtan Edison Cornpany is a Member of the General Pubhc Utattes System L
PDR ADOCK 05000289 Y-PDR
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