ML20079G918

Forwards Rev 1 to BCL-382-85-1, Exam,Testing & Evaluation of Specimens from 210-Degree Irradiated Pressure Vessel Surveillance Capsule for Oyster Creek... Per SEP Topics III-2 Re Wind & Tornado Loadings & III-7.B Re Design Codes

ML20079G918
Person / Time
Site:	Oyster Creek
Issue date:	10/03/1991
From:	Devine J GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20079G921	List: ML20079G918 ML20079G922
References
TASK-03-02, TASK-03-07.B, TASK-3-2, TASK-3-7.B, TASK-RR 5000-91-2072, C321-91-2221, NUDOCS 9110100021
Download: ML20079G918 (2)

Text

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E One Upper Pond Road Parsippany, New Jersey 07054 201-316 7000 TELFx 136-482 October 3, 1991 Wet e s Direct Dial Numter 5000-91-2072 C321-91-2221 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:

Subje- : Oyster Creek Nuclear Generating Station (0CNGS)

Docket ilo. 50 219 SEP Topic 111-2,

' Wind and Tornado loadings - Upper Reactor Building Structure", and SEP Topic 111 - 7.B.

" Design Codes, Design Criteria, Load Combinations and Reactor Cavity Design Criteria" - Related lo Drywell Temperatures and Neutron Flux

References:

1. Licensing Report on High Density Spent Fuel Racks for Oyster Creek Nuclear Generating Station, 1984.

2. Battelle Columbus Laboratories Report, " Final Report on Examination, Testing and Evaluation of Specimens from the 210-Degree Irradiated Pressure Vessel Surveillance Capsule for OCNGS," October 18, 1985.

3. Industry Ra.,nrt on Class 1 Structures Prepared for Electrical Power Research Institute Project RP-2643-27.

Unner Reactor Buildina GPUN letter dated November 15, 1990 concerning tl :,ubject matter stated that GPUN had decided to upgrade the upper Reactor Buildir.g structure by adding cross braces to the roof framing. It also stated that af ter completion of the modification, the structural stability of the Reactor Building would be maintaitied at wind speeds up to 190 mph. This analysis was performed assuming fixed connections between the Reactor Building steel superstructure columns and the concrete portion of the Reactor Building.

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. . 1 GPU Nuclear Corporation is a subsidwy of General Pubhc Utihties Corporation

' 5000-91-2072 C320 91 2221 Page 2 However, as discussed with your staff during their inspection in february,1991, CPUN agrees that this assumption does not reflect as-built configuration. We '

have recently re-analyzed the structure assuming a oinned connection between the steel columns and the co~:, ete structure. The results of this re-analysis show that after the proposed modification is complete, all members, including anchors and baseplates, will have stresses within allowables at a wind speed of 190 mph.

As requested by your staff during the inspection noted above, GPUN has also completed an analysis of the effect of a section of the Reactor Building metal siding falling into the spent fuel pool. The results of this analysis show that the maximum freces on the spent fuel racks are bounded by those resulting from a dropped fuel assembly. Stresses due to forces from a dropped fuel assembly were previously analyzed and determined to be within code limits (Ref. 1).

Temperature and Neutron Flux Data - Assessmertof-Biological shield Wall As requested by NRC Reviewer Mr. Hansraj G. Ashar during.the inspection noted above, attacbe'! (Attachment 1) are pertinent pages from Reference 2 which provide flux and Fluence data from the Oyster Creek Reactor Vessel. As stated in our letter ' dated July 17, 1991, . these radiation levels are comparable to the estimates provided in Reference 3. The estiniated radiation levels are well below the_ levels at which concrete degradation begins to occur. Therefore, radiation levels experienced during plant operation at Oyster Creek have no detrimental impact on the functionality of the biological shield wall.

A1:o attached (Attachment II) are data sheets which provide temperature readings taken in - the Oyster Creek Drywell during plant _ operation. These data were recorded at Elevations 35 and 91 near the biological shield wall during a three month period of operation. The data were requested by Mr. llansraj G. Ashar during a recent phone call. The numbers provided in our. letter of July 17, 1991 were obtained by averating temperature readings for a two year period. . As discussed in our July 17, 1991_ letter, temperatures in the range experienced by the biological shield wall at Oyster Creek have an insignificant impact on concrete strength or inodulus of elasticity.

If you have any' questions concerning this submittal, please contact Mr. Michael Laggart, Manager, Corporate Nuclear Licensing at (201) 316-7968.

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J. C. De ine, Jr Vice President and Director Technical functions JCD/YN/ pip I

cc: Administrator, Region 1 NRC Resident Inspector Oyster Creek NRC Project Manager