ML19254D005
| ML19254D005 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 09/11/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Short T OMAHA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 7910190274 | |
| Download: ML19254D005 (4) | |
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UNITED STATES S
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NUCLEAR REGULATORY COMMISSION s,.,
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September 11, 1979 Docket No. 50-285 Mr. Theodore E. Short Assistant General Manager Omaha Public Power District 1623 Harney Street Omaha, Nebraska 68102
Dear Mr. Short:
In respcnse to our letter of September 2,1977 regarding steam generator water hamer you indicated that, bued on your operating experience, modifications were not necessary to further reduce the probability or consequences of steam generator water hammer at your facility. Although your operating history does not show that such water hammer has occurred in your present piping arrangement, we require further assurance that steam generator water hamer will not occur in the future and that surveillance procedures would be adequate to decect water hamer or damace from water hammer if it were to occur.
Your response to the enclosed request for information, together with pre-viously supplied information, will provide a basis for a determination regarding the need for modifications to your feedwater system to prevent steam generator water hamer.
Your response is needed within 60 days so that we may maintain our schedule for evaluating the potential for water hammer at your facility.
Sincerely, 1/'J'/.W /
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obert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosure:
Request for Information Potential for Steam Generator Water Hammer cc w/ enclosure:
See next page 1190 042 791010M '
Onaha Public Power District CC:
ltargaret R. A. Paradis LeBoc;f, Lamb, Leiby & flacRae 1757 N Street, N.W.
Washington, D. C.
20036 Blair Public Library 166's Lincoln Street Blair, Nebraska,68008 4
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ENCLOSURE 1 o
8 REQUEST FOR INF0FSTION REGARDING THE POTENTIAL FOR STEAM GENERATOR WATER HAMM.ER AT PRESSURIZED WATER REACTORS WITH FEEDRINGS THAT DISCHARGE FROM THE BOTTOM
..k AUGUST 1979 1/ EGGOl4 t
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Provide information that demonstrates that the feedwater system and steam generator water level at your facility have been subjected to those transient conditions that are conducive to water hamer, i.e., the dition of cold feedwater or auxiliary feedwater to steam-filled # # water piping and feedring.
See NUREG 0291 Page 4 that was vwarded to you on September 2,1977.
Include the following:
1.1 Describe the expected behavior of steam generator water level as a tesult of reector trip from power levels greater than 30*J of full power.
Include actual plant measurements of stear generator level and other available related data such as feedwater flow and auxiliary feedwater flow.
1.2 Provide the number and causes of loss of feedwater events during the operational history of the plant.
You may refer to material submitted previously.
13 Provide the number and causes of loss of off-site power events during the operational history of the plant.
2.
If administrative controls have been adopted to limit the flow of auxiliary feednater for the purpose of reducing the probability of water hamer, show when they were adopted and give the answers to items 1.1, ' 2 and 1.3 for before and af ter such controls were established.
1.
If administrative controls have been adopted to limit the flow of auxiliary feedwater for the purpose of reducing the prCDability of water hamer, shcw that an adequate water inventory and flow will be maintained to accomodate all postulated transient and accident conditions.
'4.
If auxiliary feedwater flow in your facility is not at present initiated automatically for normal and accident events, present your ev31uation of whether automating the actuation of auxiliary feedwater might increase the probability of inducing steam generator water hammer.
One of the signals that would automatically initiate the flow of auxiliary feedwater would be the steam generator low water level.
This set point should be above the top of the main feedwater sparger to reduce the probability of steam generator water hammer.
5.
Describe the means that will be used to monitor for the occurrence of steam generator water hammer and possible damage fr:m such an event.
Include all instrumentation that will be emoloyed.
Describe the inspe:tions that will be perfom ed and give the fre;;sr.:y cf such insoe:tions.
6.
Describe the rescrting procecures that wiii bi use: tc dc:u e.
and reo:rt water ha r er and damage to ; iring and pi;in; su;;c-s stem.
O:n re::-:s were re:uested ir cur letter :: y:a date:
Se::em:er 2, 1977.
1190 045
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