TXX-4280, Advises That Concerns Re Radiation of Biw Silicone Insulated Cable Resolved.Calculations Examined Show Lower Postulated Dose Acceptable.Fsar Will Be Updated to Reflect New Valves in Next Amend
| ML20095G651 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/23/1984 |
| From: | Schmidt H TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| TXX-4280, NUDOCS 8408280142 | |
| Download: ML20095G651 (1) | |
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TEXAS UTILITIES GENERATING COMPANY Log # TXX-4280 6KYWAY TOWEH 400 NORTH OI,IVE MTHm,I..H. MI
- DAE I.A96.TEXAM mot Fil e # 10010 903.11 August 23, 1984 Director of Nuclear Reactor Regulation Attention: Mr. B. J. Youngblood, Chief Licensing Branch No. 1 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION D0CKET NOS. 50-445 AND 50-446 BIW QUALIFICATION REPORTS AND RADIATION LEVELS REF:
(1)TXX-4254ofAugust 10, 1984 entitled
" Environmental Qualification of BIW Cable"
Dear Sir:
In reference (1) and in a follow-up phone conversation on August 14, 1984, Texas Utilities explained that the BIW silicone insulated cable is being qualified by the two cable assembly qualification reports (BIW Report #82E080-TV, Rev.1 and the Litton report of November 1978).
This was acceptable but raised a concern about radiation.
The FSAR provides a postulated total integrated dose { TID) of 1 x 106 Rads The BIW report tested to agly 5 x 10 Rads gamma and the gamma.
Litton reporter tested to 1.1 x 100 Rads gamma.
To resolve this concern, the calculations used to determire the postulated total integrated dose were examined to see if a lower postulated dose wgs acceptable.
The existing dose calculation yielded 1.16 x 100 Rad (beta plus gamma). This calculation was found to contain conservatisms that could be justifiably reduced to yield a new postulated TID.8 The new TID is 6.67 x 107 Rads (beta plus gamma). Since the 1.1 x 10 Rads of testing performed for the Litton test report clearly envelopes this new postulated TID valve, radiation is no longer a concern in the qualification of the BIW cable.
The FSAR will be updated to reflect these new valves in an upcoming amendment.
Respectfully,
!5 O
PDR H. C. Schmidt DRW:tls Original + 40 copies Ao48
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