ML20136A935

Safety Evaluation Accepting Licensee Response to Items 2(b) & 3 of IE Bulletin 80-11, Masonry Wall Design. Licensee 850726 Request Re Wall Mods to Be Completed During Operating Cycle 11 Not Addressed

ML20136A935
Person / Time
Site:	Oyster Creek
Issue date:	12/23/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20136A906	List: ML20136A901 ML20136A935 ML20136G479
References
IEB-80-11, NUDOCS 8601020354
Download: ML20136A935 (2)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO IE BULLETIN 80-11, MASONRY WALL DESIGN GPU NUCLEAR CORPORATION JERSEY CENTRAL POWER AND LIGHT COMPANY OYSTER CREEK NUCLEAR GENERATING STATION DOCKET NO. 50-219 INTRODUCTION On May 8, 1980, the NRC issued Inspection and Enforcement (IE)Bulletin 80-11, Masonry Wall Design, which required licensees to reevaluate the design adequacy of safety-related masonry walls under postulated loads, including seismic load. GPU Nuclear Corporation and Jersey Central Power and Light Company (the licensees) responded to the bulletin by letters dated July 7 and November 14,1980; April 30,1981; August 11 and November 2, 1983; July 26, 1984; and March 21, June 14 and August 14, 1985 for Oyster CreekNuclearGeneratingStation(0ysterCreek).

DISCUSSION AND EVALUATION The findings reported in this Safety Evaluatinn (SE) are based on the attached Technical Evaluation Report (TER) (Attachment 1). prepared by Franklin Research Center (FRC) as a contractor to NRC. This TER contains the details of construction techniques used, technical infonnation reviewed, acceptance criteria, and technical findings with respect to masonry wall construction at Oyster Creek. The staff has reviewed this TER and concurs with its technical findings. The following is our sunnary of major technical findings:

1. There are 45 safety-related masonry walls at Oyster Creek.

The licensee has relied upon the working stress criteria to qualiQ the safety-related masonry walls. The licensee's working stress criteria, in general, are in compliance with the staff accept-ance criteria with two differences. These differences are dis;ussed in items 2 and 3 below.

2. Ir. several (9) of the unreinforcec walls (see p. 5 of the TER for details), the licensee's calculated values of the tensile stresses normal to the bad joint that exceeded the staff allowable values by 3%

to l h with one wall exceeding by 27%. However, as noted in the TER, the licensee's calculated values are based on conservative assumptions such as one-way bending action (rather than plate-action) and the use of the damping value of 4% (compared to the staff allowable of 7%). Therefore, taking these conservatisms into account, it is concluded that the licensee's analysis of unrein-forced walls meets the' intent of the staff acceptance criteria.

8601020354 851223 PDR ADOCK 05000219

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3. The licensee': calculated stresses in the joint reinforcement of two reinforced masonry' walls exceeded the staff allowable value by 32% (see pg. 10 of the TER) when subjected to the safe shut-downearthquake(SSE) loads. The licensee calculated these stresses by doubling'the operating basis earthquake (OBE) loads. However, in reality, the SSE loading is about 70% higher than the OBE loading. Therefore, it can be concluded that the licensee's analysis of the reinforced walls at Oyster Creek also complys with the intent of the staff acceptance criteria.

4. There are 38 safety-related masonry walls at the Oyster Creek plant which require modifications. The masonry wall modifications include the following:

• Minor preemptive modifications to 20 walls to eliminate interaction with the safety-related equipments;

• Reinforcement of the support edges;

• Installation of intemediate supports and bracings;

• Removal of excess equipment loads from walls; and -

• Repair of all visible cracks.

5. By a letter dated July 26, 1985, the licensee has requested that modi-fications to walls 15, 20, 24, 17, 18, 53, 29, 30, 31, 32, 33, 45, and 43 will be completed in Operating Cycle 11 operation rather than Cycle 11 Refueling as indicated in the TER. This SE does not address this request.

6. The licensee's approach to the wall modifications is acceptable as the modified walls will comply with the intent of the staff's acceptance criteria.

CONCLUSION Based on the above findings and the licensee's comitments, the staff concludes that the Items 2(b) and 3 of the IE Bulletin 80-11 have been fully resolved for Oyster Creek and that there-is a reasonable assurance that the safety-related masonry walls at Oyster Creek will withstand the specified design load conditions without impairment of (a) wall integrity or (b) the performance of the required safety functions. This closes out the staff's actions on IE Bulletin-80-11.

Principal Contributor: N. Chokshi.

Dated: December 23, 1985

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