ML20207M269
| ML20207M269 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 12/24/1986 |
| From: | Donohew J Office of Nuclear Reactor Regulation |
| To: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| Shared Package | |
| ML20207M276 | List: |
| References | |
| TAC-49397, TAC-62860, NUDOCS 8701130130 | |
| Download: ML20207M269 (3) | |
Text
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Do UNITED STATES
! " 3.,,.,
NUCLEAR REGULATORY COMMISSION g
g ap WASHINGTON, D. C. 20555 k....o#
December 24, 1986 Docket No. 50-219 t
Mr. P. B. Fiedler i
Vice President and Director Oyster Creek Nuclear Generating Staticn l
Post Office Fox 388 Forked River, New Jersey 08731
Dear Mr. Fiedler:
SUBJECT:
HIGH ENERGY LINE BREAK IN ISOLATION CONDENSER DRYWELL PIPING PENETRATIONS (TAC 49397,62860)
Re:
Oyster Creek Nuclear Generating Station In January,1986, Niagara Mohawk Power Corporation (NMPC) notified NRC of a condition involving a failure mode for the Nine Mile Point I drywell peretrations. Loads calculated for the penetrations due to a postulated High Energy Line Break (HELP) in the process pipino within the penetrations were determined to exceed those for which the penetrations were designed. These higher loads resulted from use of a more accurate analysis model which included both pressure and momentum effects. GPU Nuclear (the licensee) became aware of the N9PC analysis and, in February 1986, voluntarily initiated an investigation of the Oyster Creek dryvell penetrations. The results of this investigation were discussed with the staff in the meeting of August 2?,1986. The NRC meeting minutes are dated October 1, 1986.
At that time, the four piping penetrations for the Isoletion Condensers (IC) pipino were identified tc be below the updated Final Safety Analysis Report (FSARI design criteria and would fail if a guillotine rupture of the pipe occurred within the penetration. This was also reported to the staff in Licensee Event Report No.86-024, dated October 17, 1986.
Since Aucust 22, 1986, the staff bas had several telephone discussions with the licensee on this subject.
This resulted in the licensee's letters of September 17, and November 75, 1986.
In the latter letter, the licensee committed (1) to coordinate the final resolution of four piping penetrations with the resolution of NUREG-0313, Revision 2, requirements on welds inside these penetrations and with the staff's Systematic Evaluation Program (SEP)
Topic III-5.B on the two containment isolation valves outside containment on the IC steam lines and (2) to operate Oyster Creek with additional limitino conditions for operation on the reactor coolant leakage within the drywell.
The licensee stated that a physical modification cannot be made in the current Cycle 11 Refueling (Cycle 11P) outage because of the time needed to complete the design and engineering for the required modifications of the penetrations.
The penetration n'odifications would be completed in the Cycle I?R outage in 1988.
The licensee's justification for the restart from the Cycle 11P outage and l
cperation to the Cycle 12R outage is in its letters dated September 17 and November 25, 1986. The licensee stated that a recent unverified finite 8701130130 861224 l
PDR ADOCK 05000219 P
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, element analysis using reinforcement not considered in previous work and'more realistic themal-hydraulic modeling shcwed that the drywell shell at the steam line penetrations will not be overstressed due to an HELB..The licensee further stated that diagnostic techniques can be used to verify the source of an increase in unidentified leak rate if it is from a through-wall crack in a condensate return line weld in the penetration. These measures will be initiated upon a 2 gpm increase in unidentified leak rate above an established baseline leak rate.
If the investigation cannot reasonably assure the absence of a leak in an IC condensate return line weld in the penetration, a plant shutdown will commence to further investigate and analyze the leak and repair the cause as necessary. The licensee agreed by phone on December 12, 1986, that the commitment for the condensate return lines applies to the steam lines also until the analyses for these lines are verified. The plant will also be shut down if there is a 2 gpm increase in unidentified leakage within a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period.
The staff has reviewed the license's letters and data on the HELB within the IC penetrations through the drywell. As discussed in the ca.losed safety evaluation, the staff concludes that operation of Oyster Creek for operating Cycle 11 is acceptable. The modifications to the four piping penetrations will be completed in the Cycle 12R outage.
As the licensee explained its letter dated November 25, 1986, completing the modification in the Cycle 12R outage is contingent on finalizing the design of the penetrations and completing the engineering for the modifications in time for the outage. The staff will be involved in this activity with the licensee because this design will involve NUREG-0313 Revision 2 and SEP Topic III-5.B..
To expedite the design of the penetration, the staff requests a meeting at NRR headquarters in Bethesda, Maryland, no later than 4 weeks from the restart of Oyster Creek. This meeting is to discuss the licensee's conceptual design for the four penetrations. This meeting has been tentatively set between the
' licensee and the staff for January 16, 1986, unless it impacts the restart of Oyster Creek.
Sincerely.
Original signed by Jack N. Donohew, Jr., Project Manager PWR Project Directorate #1 Division of BWR Licensing i
Enclosure:
l Safety Evaluation l
cc w/ enclosure:
l See next page i
DISTRIPtlTION H. Conrad ACRS (10)
OC file i
f~NEETITel.,( BWD1 Reading E. Jordan J. Zwolinski G. Lainas NRC'PDR' R. Bernero R. Grimes J. Donohew B. D. Liaw Local PDR OGC-ETH (Info only)
.. Partlow C. Jamerson R. Hermann
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1 DBL:BWD CJa rson Jochohew JZwolinski 12/
6 If/M/86 12/f/86
Pr. P. B. Fiedler Oyster Creek Nuclear Dyster Creek Nuclear Generating Station Generatirg Station cc:
Mr. Ernest L. Blake, Jr.
Resident Inspector Shaw, Pittman, Potts and Trowbridge c/o U.S. NRC 2300 N Street, NW Post Office Box 445 k'ashington, D.C.
20037 Forked River, New Jersey 08731 J.B. Liberman, Esquire Ccmmissioner Bishop, Liberman, Cook, et al.
New Jersey Department of Energy-1155 Avenue of the Americas 101 Commerce Street New York, New York 10036 Newark, New Jersey 07102 Mr. David M. Scott, Acting Chief Regional Acministrator, Region I Eureau of Nuclear Engineering U.S. Nuclear Reaulatory Ccmmission Department of Environmental Protection 631 Park Avenue CN 411 King of Prussia, Pennsylvania 19406 Trenton, New Jersey- 08625 BWR Licensing Manager GPU Nuclear Corporation 1 Upper Pond Road Parsippany, New Jersey 07054 Deputy Attorney General State of New Jersey Department of Law and Public Safety 36 West State Street - CN 112 Trenton, New Jersey 08625 Mayer Lacey Township 818 West Lacey Road Forked River, New Jersey 08731 Licensing Manager Oyster Creek Nuclear Generating Station Mail Stop:
Site Emergency Bldg.
P. O. Box 388 Forked River, New Jersey 08731 w ? ~r.
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