ML19209B096
| ML19209B096 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 08/13/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Dewitt R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 7910090163 | |
| Download: ML19209B096 (1) | |
Text
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0 9'o UNITED STATES
! ' g -(,9,g NUCLEAR REGULATORY COMMISSION g
9 r REGION lli 799 ROOSEVELT ROAD
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GLEN ELLYN,ILLINolS 60137 Docket No. 50-155 Consumers Power Company AITN:
Mr. R. B. DeWitt Vice President Nuclear Operations 212 West Michigan Avenue Jackson, MI 49201 Gentlemen:
The enclosed IE Bulletin No. 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; Y'
Y James G. Keppler L
Director
Enclosures:
1.
List of IE Bulletins Issued in the Last 6 Honths cc w/encls:
Mr. C. J. Hartman, Plant Superintendent Central Files Director, NRR/DPM Directer, NRR/ DOR PDR Local Pl;R NSIC TIC Ronald Callen, Michigan Public Service Conunission Anthony Roisman, Esq., Attorney 1115 327 m oo90
Accession No:
7908090193 SSINS No:
6820 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WAShIMC-TON, D.C.
_20555 August 13, 1979 IE Sulletin No. 79-21 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, 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. I 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 with 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-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 measurements.
The results of this evaluation should be presented in a tabular form similar to Tables 1 and 2 of Enclosure 1.
3.
Review all safety and control setpoints derived from level signals to verify that the setpoints will initiate the action required by the plant safety analyses throughout the range of am rm
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instrumentation, including accident these setpoints.
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NRC to provide similar information.
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