ML20134G745
| ML20134G745 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 11/04/1996 |
| From: | Roche M GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 6730-96-2337, IEB-96-003, IEB-96-3, NUDOCS 9611130340 | |
| Download: ML20134G745 (3) | |
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GPU Nuclear, Inc.
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U.s. Route #9 South NUCLEAR Post Office Box 388 Forked River, NJ 08731-0388 Tel 609-9714000 November 4,1996 6730-96-2337 U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555
Dear Sir:
Subject:
Oyster Creek Nuclear Generating Station Docket No. 50-219 l
On May 6,1996, the USNRC issued Bulletin 96-003 " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors". Page 9 of that bulletin l
requires a msponse within 180 days of the date of the bulletin. The attachment to this cover letter meets that reporting requirement.
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l If any additional information or assistance is required, please contact Mr. John Rogers of my staff at 609.971.4893.
V truly yours,
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Michae Roche Vice President and Director i
Oyster Creek MBR/JJR Attachment cc:
Oyster Creek NRC Project Manager Administrator, Region I Senior Resident Inspector Sworn and Subscribed to before me this VtLday of November,1996 JW 5 W 9611130340 961104 A Notary Public of New Jersey if
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l NRC Bulletin 96-003 180 day Response l
NRC Required Response
" All addressees are required to submit the following written report (s):..Within 180 days of the date of this bulletin, a report indicating whether the addressee intends to comply with these requested actions, including a description of planned actions and mitigative strategies to be used, the schedule for implementation, and proposed TS, if appropriate:..."
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GPU Nuclear Reply GPU Nuclear intends to comply with the requested actions described in the bulletin. A modification to the torus strainers is presently scheduled to be irstalled during our next refueling outage (17R). This outage will commence during the third quarter of 1998. The modification will serve to maintain sufficient cooling capacity to meet current licensing requirements.
GPU Nuclear has participated in the development of the Boiling Water Reactor Owners Group (BWROG) Utility Resolution Guidance (URG) document, and will use this guidance in the design of the modification. Consistent with the URG, potential strainer clogging mechanisms for the Oyster Creek Nuclear Generating Station will be included in the design of the resolution of this issue. GPU Nuclear will continue to participate in the ongoing efforts to finalize the URG document.
4 At the present time, the URG document is not completed, with the test and analytical information being finalized. Resultingly, it is not possible to provide a detailed description of the final modification design package at this time. It is presently our intent to install a large capacity passive strainer to address the clogging concern. The Mark I LOCA induced hydrodynamic loads have been evaluated and the strainer calculation envelope developed. The strainer design will encompass the debris generating potential of the installed insulation at the Oyster Creek Nuclear Generating Station. Additionally, the potentiai mitigation which could be provided by replacement or encapsulation of the insulation will be included. BWROG experimental results will be utilized to support these evaluations.
During the recently completed 16R refueling outage, Foreign Material Exclusion procedures were implemented in the torus. Each of the three suction strainers weie inspected, video l
taped, and found in perfect condition, with all holes free of debris and fibrous material. All existing foreign material in the torus was removed and the torus was desludged. A sludge accumulation rate was calculated to be 50 lbs per year using the methodology in the URG.
Future desludging operations will be sci.eduled based on the accumulation rate and the assumptions made for the proposed moditication.
6730- % 2337 Page 2 The existing Oyster Creek Nuclear Generating Station Technical Specifications require a visual inspection of the torus interior at each refueling outage. Existing Preventative Maintenance tasks include inspecting the torus strainers as well as the downcomers, the vent header, and the remainder of the torus components. Therefore, no new Technical Specifications or Preventative Maintenance tasks are required, t
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