ML19256B758
| ML19256B758 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/13/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Tallman W PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| References | |
| NUDOCS 7908280339 | |
| Download: ML19256B758 (1) | |
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KING OF PRUSSIA, PENNSYLVANIA 19406 Docket Nos. 50-443 AUG 13 IM 50-444 Public Service Company of New Hampshire ATTN:
Mr. W. C. Tallman President 1000 Elm Street Manchester, New Hampshire 03105 Gentlemen:
The enclosed 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, 8h4Mk g
' (p/ Boyce H. Giier Director
Enclosures:
1.
List of IE Bulletins Issued in the Last 6 Months sc w/encls:
John D. Haseltine, Project Manager 700828u359
ENCLOSURE 1 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 TEMPERATURE EFFECTS ON LEVEL MEASUREMENTS Description of Circumstances:
On June 22, 1979, Westinghouse Electric Corporation reported, to NRC, a potential substantial safety hazard under 10 CFR 21.
The report, Attachment 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 pr2 vent protection signals and could, also, provide erroneous infor,aation during post-accident monitoring.
Attachment No. 1 addresses only a Westinghouse steam generator reference leg water column; however, safety related liquid level 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 wit.h an operating license:*
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-ac-cident 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 similar to Tables 1 and 2 of Attachment 1.
DUPLICATE DOCUMENT
- Boiling water reactors have been re E Eatire document previously NRC to provide similar information. E entered into system under:
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