ML20052A265
| ML20052A265 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/09/1982 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Parker W PENNSYLVANIA POWER CO. |
| References | |
| IEB-80-04, IEB-80-4, NUDOCS 8204280089 | |
| Download: ML20052A265 (5) | |
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DISTRIBUTION Docket File NRC PDR L PDR TERA N
Dockets Nos. 50-269, 50-270 NSIC 4
and 50-287 ORB #4 Rdg
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Mr. William 0. Parker, Jr.
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Vise President - Steam Production ACRS-10 p~M>Nd*
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422 So Ch ch Str. ret ny Charlotte, North Carolina 28242 WBut.ler Gray File
Dear Hr. Parker:
EBlackwood Our consultant, Franklin Research CNE"r,Nas reviewed your May 7,1980 response to IE Bulletin 80-04, " Analysis of a PWR Main Steam Line Break with Continued Feedwater Addition." As a result of this review some concerns have been raised.
In order for us to resolve these concerns, we request that you respond to the enclosed Request for Additional Infonnation within 45 days of your receipt of this letter.
Since this reporting requirement relates solely to the Oconee Nuclear Station, fewer than ten respondents are affected; therefore, OMB clearance is not required under P.L.96-511.
If you have any questions, please contact your NRC Project flinager.
Sincerely, N._...
-Jazmy,]Zope,Bt John F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing i
Enclosure:
Request for Additional Information cc w/ enclosure:
See next cage 820428 DOM
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pCORD COPY us e im - m 9m nnc rosu ais oo-soi sscu o24o OFFICIAL
o Duke Power Company cc w/ enclosure (s):
Mr. William L. Porter Duke Power Company P. O. Box 33189 422 South Church Street Office of Intergovernmental Relations Charlotte, North Carolina 28242 116 West Jones Street Oconee County Library 501 West Southbroad Street Walhalla, South Carolina 29691 Honorable James M. Phinney County Supervisor of Oconee County Walhalla, South Carolina 29621 Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission, Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Regional Radiation Representative EPA Region IV 345 Courtland Street, N.E.
Atlanta, Georgia 30308 Uilliam T. Orders Senior Resident Inspector l
U.S. Nuclear Regulatory Commission Route 2, Box 610 Seneca, South Carolina 29678 Mr. Robert B. Borsum Babcock & Wilcox Nuclear Power Generation Division Suite 220, 7910 Woodmont Avenue Bethesda, Maryland 20814 Manager, LIS NUS Corporation 2536 Countryside Boulevard Clearwater, Florida 33515 J. Michael McGarry, III, Esq.
DeBevoise & Liberman 1200 17th Street, N.W.
Washington, D. C.
20036 9
$4
REQUEST FOR' ADDITIONAL INFORMATION PWR MAIN STEAM LINE BREAK WITH CONTINUED FEEDWATER ADDITION DUKE POWER COMPANY OCONEE NijCLEAR STATION UNITS 1, 2, AND 3 NRC DOCKET NO. 50-269, 50-270, 50-287 FRC PROJECT CSEDS l
NRC TAC NO. 46847, 46848, 46849 FRC ASSIGNMENT 5 NRC CONTRACT NO. NRC-03-81-130 FRC TASK 134 l
Preparedby Franklin Research Center Author:
F. Vosbury 20th and Race Street Philadelphia, PA 19103 FRC Group Leader:
R. C. Herrick Prepared for r
Nuclear Regulatory Commismon We%vivn, D.C. 20665 Lead NRC Engineer:
P. Hearn l
March 15, 1982 l
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l BACKGROUND Evaluation of the information con,tained in the May 7, 1980 [1] letter from the Duke Power Company (DPC) to the U.S. Nuclear Regulatory Comunission (NRC) relating to IE Bulletin 80-04, Analysis of a PWR Main Steam Line Break with Continued Feedwater Addition, revealed an item of concern. Additional information relating to this concern is needed before a final evaluation can be made regarding the potential for exceeding containment design pressure.
This concern and the additional information needed to resolve this concern are identified in this aequest for Additional Information.
ITEM CONCERN IE Bulletin 80-04 directs the Licensee to review containment pressure response to a main steam line break (MSI2) accident to determine the impact of runout flow from the auxiliary feedwater (AFW) system and other energy sources.
In explaining their response to the MSLB accident at the Oconee Nuclear Station Units 1, 2, and 3, DPC stated:
"Following the main steam line break, the [ Integrated Control System] ICS was assumed to close the main and startup feedwater control valves after the reactor trip. No operator action to isolate the affected DTSG was assumed. Following the initial blowdown of the affected steam generator, the main feedwater flow was assumed to be supplied to the affected steam generator at a rate sufficient to maintain the design two foot level."
DPC concluded that, even though runout AFW flow was not specifically considered in the FSAR analysis, the assumptions bound the situation involving AFW flow.
DPC also stated that:
"It is to be noted that continued feedwater addition either by means of the main feedwater system or the auxiliary feedwater system in an Franidn Reneerch Center A Cheuen af The Ptemen genas f
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y a v uncontrolled manner could ultimately result in overpressurization of the containment. The Oconee Nuclear Station emergency procedure includes the requirement to isolate all feedwater into the affected steam generator."
DPC's response is not sufficient to allow FRC to complete the evaluation of the potential for exceeding containment design pressure.
Since the ICS is not safety-grade, the system cannot be relied upon to function correctly in an accident. Failure of the ICS may cause both MFW and AFW runout flow to the affected steam generator, which, as stated in.Aeference 1, could ultimatelv result in overpressurization of the containment.
4 As stated in Reference 1, the Oconee Nuclear Station procedures require that the operator isolate the MFW and APW systems to prevent containment overpressure in the even,t that a single active failure causes runout feedwater flow. However, the Licensee does not state the time margin that the operator has before the actions must be completed.
i REQUEST Please provide the following information concerning your analysis of containment pressure response to a MSLB with continued feedwater addition:
1.
An evaluation of the potential for exceeding containment design pressure using the MMt and AFN runout flow rates.
2.
Provide the time after the start of a MSLB that containment design pressure will be exceeded if no operator action is taken to terminate the accident. Provide the magnitude of the peak pressure and the time at which the peak occurs.
3.
Provide actions required to be performed by the operator to prevent exceeding containment design pressure, and provide justification for the time at which credit is taken for operator action.
G i
i REFERENCE 1.
W. O. Parker, Jr. (DPC')
Letter to J. P. O' Reilly (NBC)
Subject:
Response to IE Bulletin 80-04 May 7, 1980 4
_2 UUUU Frankun Research Center A theem af The Mamaan human
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