ML20066H873
| ML20066H873 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 11/10/1982 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 5408N, NUDOCS 8211230383 | |
| Download: ML20066H873 (2) | |
Text
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N Commonwealth Edison O ) one First National Plaza. Chicago. Illinois O
Address R: ply to: Post Offie Box 767 Chicago, Illinois 60690 November 10, 1982 Mr. Harold R. De n t o n, Director Of fice o f Nuclear Reactor Regulation U.S.
Nuclear Regulatory Commission Washington, DC 20555
Subject:
Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Containment Isolation NRC Docke t No s. 509-454, 50-455, 50-456 and 50-457 Re ference (a):
Au gust 17, 1982 letter from T.
R.
Tr amm to H. R.
De n t o n.
Dear Mr. Denton:
This is to provide advance copies o f a revision nf a response to a Byron /Braidwood FSAR question regarding containment isolation provisions.
This information will be incorporated into the FSAR in the next amendment.
Enclosed is a revised response to FSAR question 022.54 regarding valves in the containment ventilation systems which will be sealed closed during operational modes.
This response was previously revised in reference (a) to indicated that the post-LOCA purge system isolation valve would be tagged to prevent operation during power i
operation, startup, hot standby, and hot shutdown.
Af ter further review it appears that r emoval o f the fuses from the circuit supplying power to the actuator solenoid will provide additional assurance that j
the valve will not be inadvertently, opened.
The enclosed response to question 022.54 has been revised to include this commitment,
j Please address questions regarding this matter to this of fice.
One signed original and forty copies of this letter are l
provided for your review.
Ve ry truly yours, i
ma f~~
Sool T.R.
Tramm Nuclear Licensing Administrator 1m i
Attachment 8211230393 821110 5408N PDR ADOCK 05000454 A
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ATT AC HMEN T QUESTION 022.54
" Verify that the normal containment purge system isolation valves (1VQ001A, B, and IVQOO2A, B) and post-LOCA purge system isolation valve IVQ003) will be sealed closed (as defined in SRP Section 6.2.4, 11.2.f) during the operational modes o f power operation, startup, hot standby, and hot shutdown."
R ES PONSE The normal containment purge valves will be locked closed by the administrative procedure of interrupting power to the valve at the circuit breaker (i.e., the circuit breaker will be racked out) and tagging the breaker "out of service."
Inadvertant operation of the purge valves requires violation o f procedures prohibiting both the operation of tagged-out equipment and the containment purge system.
Tagging out at the breaker is considered equivalent to a mechanical lock because in both instances positive action is used to prevent the valve from receiving power and an administrative procedure is required to return the breaker to service.
Tne Post-LOC A purge system isolation valve, IVQ003, is a solencid operated valve powered from Ulvision 12 120VAC ESF distribution panel.
Interrupting power to IVQOO3 is accomplished by reiaoving the fuses in the 120 VAC power supply.
Removing and tagging 00S the fuses and tagging the control switch 00S will provide the equivalent to a mecahnical lock as stated above.
The fuses supplying power to IVQOO3 will be removed and tagged 00S during power operation, startup, hot standby, and hot shutdown.
Valve IVQOO3 is identical to valves IVQOO4A/B, and IVQOOSA/B, the miniflow containment isolation valves, and is equipped with an operator capable of closing the valve in 5 seconds for containment isolation (see Table 6.2-58).
i 5408N
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