ML20003E669
| ML20003E669 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 03/26/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Finfrock I JERSEY CENTRAL POWER & LIGHT CO. |
| References | |
| LSO5-81-03-060, LSO5-81-3-60, NUDOCS 8104080134 | |
| Download: ML20003E669 (4) | |
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Mr. I. R. Finfrock, Jr.
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Vice President Jersey Central Power & Light Company ACRS(16)
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Oyster Creek Nuclear Generating Station mk% /
Y Post Office Box 388 Forked River, NJ 08731
Dear Mr. Finfrock:
We are continuing our review of the scram and " spurious" triple low level that occurred on July 17, 1980 at the Oyster Creek Nuclear Generating Station and have found that additional information described in the enclosure to this letter is needed.
In a tele-phone conversation on March 10,1981 Mr. James Knubel of your staff indicated that General Public Utilities Nuclear Group (GPUNG) is preparing a report on this event which will be provided to tne NRC when it is completed in about one month. It was indicated that most of the information requestel in the enclosua could be included in the report that GPUh6 is preparing. For thos.21tems that will not be addressed in the report, please pmvide a response within 30 days of the receipt of this letter.
Sincerely, Original Signed by Dennis M. Cmtchfield, Chief Operating Rsactors Branch #5 Division of Licensing
Enclosure:
As stated cc w/ enclosure:
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j MM C 61931 Docket No. 50-219 L505-81-03-060 Mr. I. R. Finfrock, Jr.
Vice President Jersey Central Power & Light Company Oyster Creek Nuclear Generating Station Post Office Box 388 Forked River, NJ 08731
Dear Mr. Finfrock:
We are continuing our review of the scram and " spurious" triple icw level that occurred on July 17, 1980 at the Oyster Creek Nuclear Generatir.g Station and h:ve found that additional information described in the enclosure to this letter is needed.
In a tele-phone conversation on March 10,1981, Mr. James Knubel of your staff indicated that General Public Utilities Nuclear Group (GPUNG) is preparing a report on this event which will be provided to the NRC when it is completed in about one month.
It was indicated that most of the information requested in the enclosure could be included in the report that GPUNG is preparing. For those items that will not be addressed in the report, please provide a response within 30 days of the receipt of this letter.
Sincerely, ut4E4 Dennis M. Crutchfield, C. ef Operating Reactors Branch #5 Division of Licensing
Enclosure:
As stated cc w/ enclosure:
See next page e
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Mr. I. R. Fi nf rock, J r.
cc G. F. Trowbridge, Esquire Gene Fisher Shaw, Pittman, Potts and Trowbridge Bureau Chief 1800 M Street, N. W.
Bureau of Radia' ion Protection Washington, D. C.
20036 380 Scotts Road.
Trenton, New Jersey 38628 GPU Service Corporation ATTN: Mr. E. G. Wallace Comissioner Licensing Manager New Jersey Decartment of Energy 260 Cherry Hill Road 101 Comerce Street Parsippany, New Jersey 07054 Newark, New Jersey 0/102 Natural Resources Defense Council Plant Superintendent 91715th Street, N. W.
Oyster Creek Nuclear Generating Washington, D. C.
20006 Station P. O. Box 388 Forked River, Nqs Jersey 08731 Steven P. Russo Esquire 5
. 248 Washington Street Resident Inspeci or P. O. Box 1060 c/o U. S. NRC
- Toms River, New Jersey 08753
-P. O. Box 445 Fcrk ed River, NW Jersey 08731 Joseph W. Ferraro, J r., Esquire Deputy Attorney General Director, Criter la and Standards State of New Jersey
. Division Department of Law and Public Safety Office of Radiation Programs 1100 Raymond Boulevard (ANR-460)
Newark, New Jersey 07012 U. S. Envirencental Protection Agency Ocean County Library Washington, D. C.
20460 Brick Township Branch 401 Chambers Bridge Road U. S. Environcer :al Protection Brick Town,. New Jersey 08723 Agency Region II Office.
Mayor ATTN: ' EIS C00RC;[NATOR Lacey Township 26 Federal Plazzi P. O. Box 475 New York, New Yc}-k 10007 Forked. River, New Jersey 08731
'Comissioner Department of Public Utilities State of New Jersey 101 Comerce Street Newark,- New Jersey 07102.
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ENCLOSURE QUESTIONS CONCERNING THE 7-17-80 TRIPLE LCW EVENT AT OYSTER CREEK 1.
Do the Recirculation Pumps have vibration trip or alarm, which may indicate pump cavitation? What do the procedures tell the operator to do? How long does he have to do required action?
2.
Did the Recirculation Pumps show decreased amperage when recirculation flow decreased?
3.
Provide the feedwater flow data during the event.
4.
Do the continuing triple alam/ indications, recirculation loop saturation condition, and apparent pump cavitation indicate basic system instability? (Between annular and core regions?)
1.e., do small pertubations in the annular region cause large level swings in the core region?
5.
Could there have been a core-annular region disconnect when recircu-lation flow went to zero or cavitated? If so, how long before a manual action is necessary? How is this addressed in the emergency procedures?
6.
What do procedures tell operator for appropriate action when recircula-tion flow goes to zero?
7.
Explain why Oyster Creek has had spurious triple low signals. What improvement in design or operation can be made to eliminate spurious triple low alarms?
8.
What does the operator 'do if he gets a triple low alam? Is this addressed in the emergency procedures?
9.
What caused the recirculation flow to go to zero? Was it instrument error due to two phase mixture in instrument lines or sensing elements, or was it cavitation in the recirculation pump?
'.10.
Why does the temperature increase while the pressure is decreasing during the event?- Is this a conr. action with the feedwater flow?
- 11. What effect does operation of the recirculation pumps have on level measurement?
.' 12. Provide the data from the event recorder that is used to analyze the significant events during the July 17, 1980 transient.
In particular, supply the data that.is' used to calculate the core quality change and density change with reduced recirculation flow.
Provide ~the data to show the natural circulation driving head in the recirculation loops during periods of minimum pump flow.
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- 13. Provide assurance that the core does not 90 into film boiling during periods of minimum or degraded recirculation flow.
- 14. Protide analyses to show that a density change occurs fast enough to perturbate a 0.5 second triple low level blip on the event
- recorder.
- 15.. Indicate whether your procedures-instruct the operator to keep RBCCW
- available when it is beneficial for transient mitigation, if it automatically isolates during an event.
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