ML19253A496
| ML19253A496 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/13/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Cavanaugh W ARKANSAS POWER & LIGHT CO. |
| References | |
| NUDOCS 7909100158 | |
| Download: ML19253A496 (1) | |
Text
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o, UNITED STATES NUCLEAR REGULATORY C07,1 MISSION g
S fp;A 611 RYAN PLAZA DRIVE. SUl *E 1000 p,c gg{g
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ARLINGTON, TEXAS 700 f 2 August 13, 1979 Docket Nos.
50-313 50-368, Arkansas Power and Light Company ATTN:
dr. Willian Cavanaugh III Vice President of Generation and Construction P. O. Box 551 Little Rock, Arkansas 72203 Centlenen:
Enclosed is IE Bulletin 79-21 which requires action by you with regard to your PWR power reactor facilities with an operating license.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely, f
R. k.
2 Karl V. Seyfrit Director
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Enclosures:
1.
IE Bulletin Jo. 79-21 2.
List of IE Bulletins Issued in the Last 6 Months James P. O'Hanlon, Plant Manager cc:
Arkansas Nuclear One P. O. Box 603 Russellville, Arkansas 72801 005 b~
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7'900100/f[
t 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 Descripti'n 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 contairrant temperature on the reference leg water column and the resultant effect :2 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 To. 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 syatems within containment to determine if the signals are used to initiate safety actions or are used to provide post-rccident monitoring information. Previde 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 similar to Tables 1 and 2 of Enclosura 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 ambient te instrumentation, including accident ]Ma 1
these setpoints.
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- Boiling water reactors have been reques into system under:
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