ML19253A488
| ML19253A488 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/13/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Gary R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| References | |
| NUDOCS 7909100134 | |
| Download: ML19253A488 (1) | |
Text
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k' UNITE D STATES y" f,.., f' h NUCLEAR REGULATORY COMMISSION i M/. s REGION IV SA 4
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Gil RYAN PL AZA DRIVE, SUITE 1000
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ARLINGTON, T EX AS 76012 h
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August 13, 1979 In Reply Refer To:
RIV Docket Nos.
50-445/IE Bulletin 79-21 SC-4.'.6/IE Bulletin 79-21 Texas Utilities Generating Co=pany ATTN:
.t.
- 2. J. Gary, 20:ecutive Vice President and General Manager 2001 Bryan Tower Dallas, Te::as 75201 Gentlecea:
The enclosed IE Bulletin 79-21 is forwarded to you for information. No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
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Karl V. Sey'fri Director
Enclosures:
1.
Listing of IE Bulletins Issued in Last 6 Months 0 9 % v '. {l) a u u-. a
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UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 79-21 Date: August 13, 1979 Page 1 of 2 T N r; C 2E EFFECTS ON LEVEL MEASUREMENTS Descriptica of Circumstances:
On June 22, 1979, Westinghouse Electric Corporation reported to NRC a potential substantial safety hazard under 10 CFR 21.
The report, Enclosure No. 1, addresses the effect of increased containment temperature on the reference leg water column and the resultant effect on the indicated steam generator water level.
This effect would cause the indicated steam generator level to be higher than the actual level and could delay or prevent protection signals and could also provide erroneous information during post-accident monitoring.
Enclosure No. 1 addresses only a Westinghouse steam generat' r reference leg water column; however, safety related liquid 1cvel o
measuring systems utilized on other steam generators and reactor coolant systems could be affected in a similar manner.
Actions To Be Taken By Licensees:
For all pressurized water power reactor facilities with an operating license:h 1.
Review the liquid level measuring systems within containment to determine ~
if the signals are used to initiate safety actions or are used to provide post-accident monitoring information.
Provide a description of systems that are so employed; a description of the type of reference leg shall be included, i.e., open column or sealed reference leg.
2.
On those systems described in Item 1 above, evaluate the effect of post-accident ambient temperatures on the indicated water level to determine any change in indicated level relative to actual water level. This evaluation must include other sources of error including the effects of varying fluid pressure and flashing of reference leg to steam on the water level measure-ments.
The results of this evaluation should be presented in a tabular form sinilar to Tables 1 and 2 of Enclosure 1.
3.
Review all safety and control setpoints derived from 1cvel signals to verify that the setpoints will initiate the action required by the plant safety analyses throughout the range W I
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instrumentation, including acc O
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DUPLICATE DOCUMENT these setpoints.
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Entire document previously entered into system under:
xBoiling water reactors have been 7 f Ohhh O/
the NRC to provide similar inform ANO No. of pages:
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