ML20245H419

Forwards Table 1 Summarizing Assessment of Drywell Corrosion to Date & Projected Corrosion Rate for Operating Cycle,Per 880912 Commitment.Nrc Concurs W/Util That Actions Taken or to Be Taken Ensure Drywell Integrity

ML20245H419
Person / Time
Site:	Oyster Creek
Issue date:	04/28/1989
From:	Dromerick A Office of Nuclear Reactor Regulation
To:	Fitzpatrick E GENERAL PUBLIC UTILITIES CORP.
References
TAC-72029, NUDOCS 8905030394
Download: ML20245H419 (5)

Text

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[k og-UN!TED STATES g

NUCLEAR REGULATORY COMMISSION r.

Oj WASHINGTON, D. C. 20555

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April 28, 1989 Docket No. 50-219 l

Mr. E. E. Fitzpatrick Vice President and Director Oyster Creek Kuclear Generating Station Post Office Box 388 fcrked River, New Jersey 08731 Cehr ftr. Fitzpatrick:

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SUBJECT:

DRYWELL CONTAINMENT - OYSTER CREEr NUC' LEAR GENERATING STATION (TACNO.72029) l i

In a letter dated Septenter 12, 1988, GPUNuclearCorporation(GPUN/the i

licensee) comitted to provide an assessment of the drywell corrosion to j

dtte (12 Refueline cutage) anc the projected corrosion rate for the following operating cycle.

In a letter dated February 9, 1989,-CPUf; provided the staff with this information. The pertinent information as given by GPUN is summarized in Table 1 (enclosed).

j On the basis cf the corrosion rate listed in Table 1, the licensee concluded that the.ncst limiting condition is in the sand bed region of the drywell'shell J

and the drywell shell thickness is projected to be acceptable until June 1992.

In an attempt to reduce the corrosion rate, the licensee has (1) installed cathodic protection in selected sand bed locations, (2) taken steps to eliminate water leakage from reactor building equipment and refueling cavity, and (3) i drained water from sand bed region.

In order to assure the structural integrity of the drywell, the licensee has committed pericdic UT thickness measuren,ents of

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the drywell shell c,t all cttages of opportunity.

The licensee enp esized that the projection to June 1992 was based on conservative apprcaches.

Dased on our review of the information provided by GPUN, we concur with the i

licensee that ith the actions taken and to be taken by the licensee to ensure i

drywell integt ty, and that plant'eperation can continue to the 13R refueling cutage.

In the event that efforts to arrest corrosion are not successful the licensee has argued that existing conservatism would still allow operation.-

However, the staff has reservations due to the fact that such conservatism are not easily quantifiable and are required in assuring drywe11' adequacy for the protection of public health and safety. The licensee is required to perform r

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'Mr.' E. E. Fitzpatrick April 28, 1989 thickness measurements and reconfirm the adequacy of the containment integrity at future outages of opportunity, inc1Lding. forced cutages requiring drywell entry during the next cycle, but no later than prior to the resumption of power operation following the 13R refueling outage.

Sincerely,

i

/s/

Alexander W. Dromerick, Project Manager Project Directorate I-4 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation

Enclosure:

Table 1 l

I cc w/ enclosure:

l Sec next page DISTRIBUTION IDockets' File o a l

NRC &~ Lbcal 'PDRs PDI-4 Reading SVarga,14/E/4 BBoger,14/A/2 SNorris ADromerick OGC (for info. only)

E. Jordan, 3302 MNBB ACRS(10),9/A/2 B. Grimes 1

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[0YST CRK DRYWELL CONT 72029]

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i Mr. E. E. Fitzpatrick,

l thickness neasurencnts and reconfirm the adequacy of the containment integrity at future outages of opportunity, including forced outages requiring drywell entry during the next cycle, but no later than prior to the resumption of pwer operation folluwing the 13R refueling outage.

Sincerely,

t

/

Alexander W. Dromerick, Project Manager Project Directorate I-4 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation

Enclosure:

l Table I cc w/ enclosure:

See next page I

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l Mr. E. E. Fitzpatrick Oyster Creek Nuclear 4

Oyster Creek Nuclear Generating Station Generating Station I

l cc:

i Ernest L. Blake, Jr.

Resident Inspector Shaw, Pittman, Potts and Trowbridge c/o U.S. NRC 2300 N Street, NW Post Office Box 445 Washington, D.C.

20037 Forked River, New Jersey 08731 J.B. Liberman, Esquire Consnissioner Bishop, Liberman, Cook, et al.

New Jersey Department of Energy 1155 Avenue of the Americas 101 Conrnerce Street New York, New York 10036 Newark, New Jersey 07102 1

Jennifer Moon, Acting Chief Regional Administrator, Region I New Jersey -Department of Environmental U.S. Nuclear Regulatory Commission Protection 475 Allendale Road Bureau of Nuclear Engineering King of Prussia, Pennsylvania 19406 CN 415 i

Trenton, New Jersey 08625 BWR Licensing Manager l

GPU Nuclear Corporation 1 Upper Pond Road Parsippany, New Jersey 07054

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Deputy Attorney General State of New Jersey Department of Law and Public Safety 36 West State Street - CN 112 Trenton, New Jersey 08625 4

Mayor 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

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EllCLOSURE -

TABLE 1

-Thickness (Inch)

Corrosion Location Nominal Code Req'd UT Measured Rate (Elevation)

(MPY) 8'-11 3/4" to 12'-3" 1.15 0.700 0 838

-27.6 + 6.1 (sandbedregion) 50' - 2" 0.77

.725 0.750

-4.3 +.03 87' - 5" 0.64

.639 0.620*

0

• Accepted on the basis of data f rom certifiec niaterial test reports (CMTRs) aiid no corrosion af ter plant operation (corrosicti cccorred during electicti).

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