ML19345A442
| ML19345A442 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 05/11/1973 |
| From: | Johnson W YANKEE ATOMIC ELECTRIC CO. |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8011210540 | |
| Download: ML19345A442 (2) | |
Text
Ri'ulatory No Cy.
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YANKEE ATOMIC ELECTRIC COMPANY
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W :.. M. ::: l '....;g 0's United States Atomic Energy Commission
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Attention: Directorate of Licensirg o) cn
Reference:
License No. DPR-3 (Docket No. 50-29)
Dear Sirs:
Pursuant to Section 50-59 of the Commission's Regulations, Yankee Atomic Electric Company hereby requests to make the fo11 ewing change:
PROPOSED CliANGE:
Reference is made to Section 214 of the license application, Nuclear Instrumentation and Reactor Protection System and particularly to the permissive circuitry description on pages 214:5 and 214:6 and to Turbine Shutdown S Reactor Scram block diagram No. 9699-FE-2G.
We propose the following:
"To disconnect the reactor permissive relay pressure switches from the turbine first stage pressure sensing line. and to reconnect them to the turbine #1 no::le pessure.c asing line which presently serves only as a source c no::le pressure indication."
Re
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Since the return to normal operation following an extended control rod / shroud tube replacement shutdown, a change in turbine first stage pressure has been noted. At 180 MWeg the normal first stage pressure should be approximately 400 psig.
Immediately after the unit was returned to service, first stage pressure was noted to be approximately 300 psig, and has since decreased to 230 psig.
It is believed that sensing line leakage into the high pressure turbine is the cause of the erroneous first stage pressure indication.
Description of Change: The four pressure switches (418, 418A, 420 6 421) which presently sense turbine first stage pressure will be removed from service.
Four new pressure switches with a larger operating range will be installed in their place. The sensing line which presently supplies the pressure switches will be disconnected at a location inside the turbine startup panel and the new pressere switches will be connected to the #1 no::le pressure sensing line whid is also located 8011210 E90
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United St:tes Atomic Energy Commission May 11, 1973 Attn: Directorate of Licensing Page Two within the turbine startup panel. The new pressure switches (418, 418A and 420) will be set to operate at that nozzle pressure which is equivalent to = 15 MWe, and pressure switch 421, which presently operates at a pressure equivalent to 485 MWt and acts to disallow continuous rod motion above this point, will be conservatively adjusted i
to perform the same function at a pressure which is equivalent to j
% 30 MWe, Installation and pre-operational testing of this change will be performed in accordance with approved written procedures.
Safety Considerations: This change does not affect the proper operation of the reactor and the generator protection system. The permissive circuits remain unchanged except for the source of the initiating signal, and the pressure at which the permissive switches operate.
Data taken during the most recent plant startup and during a subsequent throttle valve exercise verifies that the range of pressure measured within the #1 nozzle chamber makes it an acceptable source from which to take the permissive relay initiating signal.
Respectfully submitted, YANKEE ATOMIC ELECTRIC COMPANY 1
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3 W. P ohnson
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Assistant Vice President MAY.161973>
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4 Then personally appeared before me, Wendell P. schnson, who, being duly sworn did state that he is an Assistant Vice President of Yankee Atomic Electric Company, that he is duly authorized to execute and file the foregoing request in the name and on the behalf of Yankee Atomic Electric Company, and that the statements therein are true to the best of
'i his knowledge and belief.
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Armand R. Soucy Notary Public My Commission Expires September 9, 1977 3212