ML20215L274

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Requests Relief from Compliance W/Exam Requirements of Winter 1980 Addenda to ASME Boiler & Pressure Vessel Code,Section XI Re Rules for Insp of Nuclear Power Plant Components.Fee Paid
ML20215L274
Person / Time
Site: Fort Calhoun Omaha Public Power District icon.png
Issue date: 10/24/1986
From: Andrews R
OMAHA PUBLIC POWER DISTRICT
To: Thadani A
Office of Nuclear Reactor Regulation
References
LIC-86-482, TAC-63318, NUDOCS 8610280552
Download: ML20215L274 (2)


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Omaha Public Power District 1623 Harney Omaha. Nebraska 68102-2247 402,536-4000 October 24, 1986 LIC-86-482 Mr. Ashok C. Thadani, Project Director PWR Project Directorate #8 Division of PWR Licensing - B Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, DC 20555

Reference:

Docket No. 50-285

Dear Mr. Thadani:

Relief Request from Particular Requirement (s) of ASME Boiler and Pressure Vessel Code,Section XI Pursuant to 10 CFR 50.55a(g)(5)(iii), the Omaha Public Power District is for-warding for approval the attached relief request for the Fort Calhoun Station.

In reviewing the requirements of the Winter 1980 Addenda to the ASME Boiler and Pressure Vessel Code, it has been determined that the requirements from Table IWC-2500-1, Cat. B-N-1, Item B13.10 would result in information of limited value and also would cause unnecessary radiation exposure The attachment spec-ifically defines our reasons for this conclusion. The $150.00 application fee required by 10 CFR 170 is also enclosed.

Your attention to this matter in order to resolve it in time for the 1987 re-fueling outage would be appreciated.

Sincerely

/

R. L. Andrews

, Division Manager l

Nuclear Production RLA/me 8610280552 861024 5 Attachment PDR ADOCK 0000 G

cc: LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.

Washington, DC 20036 Mr. D. E. Sells, NRC Project Manager p Mr. p. H. Harrell, NRC Senior Resident Inspector O d g 0

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Request for Exemption from Compliance with the Examination Requirements of the Winter 1980 Addenda to the ASME Boiler and Pressure Vessel Code,Section XI, Rules for Inspection of Nuclear Power Plant Components.

EXCEPTIONS, CLASS 1. Reactor Pressure Vessel Visuals Table IWB-2500-1, Cat. B-N-1, Item B13.10, requires the Omaha Public Power District to perform a visual examination of accessible areas of the reactor vessel interior once per prescribed inspection interval (approximately every three years).

The visual examination is conducted to determine the general mechanical and structural conditions of components and their supports, such as the presence of loose parts, debris, or abnormal corrosion products, wear, erosion, corrosion, and the loss of integrity at bolted or welded connections. It is intended that the visual examinations will be scheduled to coincide with scheduled plant outages.

Normally, during scheduled plant outages at Fort Calhoun Station, only the uppermost 8 inches of the reactor vessel interior is accessible for visual examination. Accessibility is limited by the design of the reactor vessel and is caused by mechanical interference presented by the instrument flange on top of the core support barrel.

Because of the limited accessibility to the reactor vessel internals, the information gained from visual examination is small compared to the radiation exposure received by personnel performing the examination. The components that can be examined are not attached by bolted or welded connection and the probability of detecting loose parts, debris, or abnormal corrosion products, wear, erosion, and corrosion in such a limited area is small.

During those plant outages when the core support barrel is removed, the reactor internal surfaces are accessible. Under these conditions meaningful information can be obtained by the prescribed visual examinations. Normally, the core support barrel is removed during plant outages corresponding to the end of each ten year interval. The entire reactor vessel interior was visually examined in 1983 during the first ten year ISI examination. There were no visual indications detected at that time which could be classified as unusual or unacceptable.

It is the opinion of OPPD that the requirement of B13.10 to perform visual examination of accessible reactor vessel internals was not intended for such limited areas as those encountered at Fort Calhoun Station. It is also the opinion of OPPD that the information gained by the prescribed examinations does not warrant tM radiation exposure to which personnel performing the examinations are subjected.

Therefore, because safety is not enhanced by examining such a small accessible area and because of the radiation exposure to personnel when performing the examination, OPPD requests that an exemption be granted from performing the examination required by IWB-2500-1, Category B-N-1, Item B13.10, except for those plant outages when the core support barrel is removed.

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