ML19270H515
| ML19270H515 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/04/1974 |
| From: | John Miller METROPOLITAN EDISON CO. |
| To: | |
| Shared Package | |
| ML19270H513 | List: |
| References | |
| NUDOCS 7910260704 | |
| Download: ML19270H515 (1) | |
Text
l lgjj
,/
t;,,,,,
n u nn n w ass i
/
/
/ METROPOLITAN EDISON COMPANY
._ ~<accrecmsvooono.
a:we 07r CFFICE BOX 542 READING. PENNSYLVANI A 19603 TELEPHONE 215 - 929G601 April 4, 1974 Dr. D. F. Knuth, Director Directorate of Regulatory Operations Office of Regulation U.S. Atomic Energy Comission Washington, DC 20545
Dear Dr. Knuth:
SUBJECT:
THREE IfILE ISLAND NUCLEAR STATION UNIT 1 DOCKET N0. 50-289 DIESEL GENERATORS You were notified on March 4, 1974, of a situation which =ay be considered reportable under 10 CFR 50.55(e), " Conditions of Construction".
This situation related to the Diesel Generators.
The Diesel engines had been warmed and manually shut down in preparation for surveillance tests. This action energizes and seals in the automatic shutdown relay. During engineered safeguards surveillance tests, the diesel generators failed to run when given a start signal.
Investigation of the engineered safeguards test logic revealed that one test channel (one of two) does not override the shutdown relay, whereas the second channel, or an actual safeguards sian do override this relay.
This was the reason for the failure to start.
The applicable procedures are being revised to sequence the pre-parations and test steps to assure proper checking of the safecuards contacts in the Diesel Generator circuitry.
Engraved instructions have been placed at the engines to emphasize the operational requirements to assure the diesel generators are reset properly.
Additionally, the design agent is conducting a separate review of the safeguards test requirements relative to the diesel generator circuit logic. The results of this review will be available for your review at the Three Mile Island site.
t 7
Very truly yours, W
y y. C. Miller Vice President asb
$910260 Ch