ML19322B706
| ML19322B706 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/10/1977 |
| From: | Parker W DUKE POWER CO. |
| To: | Rusche B, Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7912050709 | |
| Download: ML19322B706 (3) | |
Text
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NRCse;nu 195 U.C. NUCLE AR FiEGULAToRY C 41538oN DOCKET NUMIE R 82 den 50-269/270/287 NRO DISTRIBUTION FoR PART 50 DOCKET MATERIAL
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FROM:
DATE oF DOCUMENT TO:
Duke Power Company 3/10/77 Mr. Benard C. Rusche Charlotte, North Carolina oATE RECEivEo Mr. William O. Parker, Jr.
3/14/77
% LETTER O NoToRIZ E o PROP INPUT FORM NUMBER oF COPIES RECEIVED CoRiclNAL kNC LASSIFIE D OCoPv -
i One signed DESCRIPTION ENCLOSURE Ltr. re our 1/14/77 ltr..... trans the following:
Consists of evaluation of refueling accident inside containment.....
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March 10,1977 FCE P#ES;ct=Y
- C.E Pa*C N E: A# C4 7C4 3 7t ane P*ODuC?>O*e 373-4093 Mr. Benard C. Rusche, Director Of fice of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. A. Schwencer, Chief Operating Reactor Branch #1
Reference:
Oconee Nuclear Station
. - -, vf p r.t!**'".=" ~ m m Docket Nos. 50-269, -270, -287
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Dear Sir:
Your letter of January 14, 1977 enclosed a letter from Mr. R. D. Pollard which stated that a refueling accident inside the containment building may not have been adequately considered during the licensing review of the Oconee Nuclear Station. It was requested that we provide the results and factors involved in the evaluation for two cases: (1) a conservative analysis using parameters as limited by the Technical Specifications, and (2) an analysis using parameters associated with known facility operating conditions.
In response to this request, an extremely conservative analysis was per-formed for this postulated accident utilizing assumptions comparable to those given in Regulatory Guide 1.25.
The results of this evaluation, discussed in Attachment 1, were shown to provide a site boundary exposure of 0.5 rem to the whole body and 32 rem to the thyroid. These doses are well within the 25 rem whole body and 300 rem thyroid dose criteria estab-lished in 10CFR100. Considering the demonstrated results of the conserva-tive evaluation, the extremely remote probability of the postulated acci-dent, and the effort required to perform analysis using parameters associated with known facility operating conditions, it is felt tiiat sufficient infor-mation is provided for your review of this matter.
Very truly yours,
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h-WilliamO. Parker,(r)
MST:ge 2684
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ATTACIDiENT I EVALUATION OF REFUELING ACCIDENT INSIDE CONTAINMENT A conservative analysis of the effect of a fuel handling accident inside the containment building has been performed. This analyses has considered para-meters as limited in the Technical Specifications and was performed using methods and assumptions specified in Regulatory Guide 1.25.
A summary of i
the pertinent assumptions is as follows:
l.
The accident occurs 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after reactor shutdown.
Earlier fuel 3
movement is prohibited by Technical Specification 3.8.11.
2.
The minimum water depth between the top of the damaged fuel rods and the water surface is 23 feet.
3.
The maximum fuel rod pressurization is less than 1200 psi.
4.
All gap activity in all rods of the af fected assembly is released and consists of 10% of the total noble gases other than Kr-85, 30% of the Kr-85, and 10% of the total radioactive iodine.
5.
The values assumed for individual fission product activity are calculated assuming full power operation at the end of core life immediately preced-ing shutdown. A radial peaking factor of 1.65 is assumed.
6.
The iodine gap activity is composed of inorganic species (99.75%) and organic species (0.25%).
7.
The decontamination factors for the inorganic and organic species are j
133 and 1 respectively.
i 8.
The retention of noble gases is negligible.
9.
The radioactive material that escapes is released instantaneously and no hold up time is considered.
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- 10. No credit is assumed for installed filtar systems.
- 11. The activity is released at ground level and the atmospheric dispersion factors used are in accardance with those in the bases of Technical Specificaion 3.10.
The result of this conservative analysis indicate that a 0.5 rem whole body and 32 rem thyroid dose at the site boundary could occur in the event of this j
highly unlikely accident. This is well within the guidelines established in 10CFR100.
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