ML19345D624
| ML19345D624 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/10/1980 |
| From: | Hovey G Metropolitan Edison Co |
| To: | Barrett L Office of Nuclear Reactor Regulation |
| References | |
| TLL-653, NUDOCS 8012160273 | |
| Download: ML19345D624 (2) | |
Text
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Metropditan Edismt Company l I I {.
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I Post Office Box 480 Middletown, Pennsylvania 17057 Writer's Direct Dial Number
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December 10, 1980 TLL 653 TMI[trogramOffice Attn; Mr. Lake Barrett, Deputy Director U. S' Nuclear Regulatory Commission c/o Three Mile Island Nuclear Station Ndddletown, Pennsylvania 19406
Dear Sir:
Three Mile Island Nuclear Station, Unit 2 (TMI-2)
Operating License No. DPR-73 Docket No. 50-320 Reactor Decay Heat Removal In our letter, TLL 633, dated December 4, 1980, concerning Loss to Ambient Test Results, we stated that we were in the process of revising our operating procedures to enable us to use the Loss to Ambient
- cooling mode for reactor decay heat removal. We further stated that until your approval of that operating proced re was obtained, we would continue use of steaming our "A" OTSG as the method of reactor decay heat removal.
The test procedure used to conduct the Loss to Ambient Test required that the turbine bypass valve isolation valve be closed, isolating the "A" OTSG from the condenser and hence, removing the capability to steam on "A" OTSG. To return to the steaming mode of core cooling, opening the isolation valve to the turbine bypass valve is required. Doe to a lack of complete communication, the system configuration was improperly stated in our December 4, 1980, letter. The isolation valve remained closed and until December 9, 1980, we remained in the Loss to Ambient mode of core cooling.
On that date, we re-opened the isolation valve which re-established "A" OTSG steaming mode of core cooling.
As a result of the aforementioned operational scenario, the health and safety of the public was not jeopardized. Because of the level of decay heat generation, irrespective of the stated cooling mode, l
(i.e., the position of the isolation valve), this decay heat is l
rejected from the reactor core primarily through the Loss to Ambient mode.
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N3 B01216 0 vetropoi, tan Ee. son company.s a uember ot rne Generai Pubne um.t es system Y
Like barrett
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Should you wish to discuss this matter further, please contact the undersigned or Mr. L. J. Lehman, Jr. (Ext. 8693), of my staff.
Sincerely,
/s/ G. K. Hovey G. K. Hovey Vice-President and Director, DfI-2 GKH:1JL: dad cc:
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