ML19275A275

RO 50-336/79-27:during Engineering Review,Section of 4-inch Cast Iron Floor Drain Piping Passing Each Station Battery Was Found Not Supported in Accordance W/Design.Drain Working & Ductwork Removed

ML19275A275
Person / Time
Site:	Millstone
Issue date:	09/25/1979
From:	Opeka J NORTHEAST UTILITIES
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
MP-2-4142, NUDOCS 7910030443
Download: ML19275A275 (2)

Text

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September 25, 1979 MP 4142 Mr. Boyce H. Grier Director, Region I ,

Office of Inspection and Enforcement U. S. Nucleer Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

Reference:

Facility Operating Licens3 No. DPR-65 Docket No. 50-336 Reportable Occurrence 50-336/79-27

Dear Mr. Grier:

This letter provides notification of Reportable Occurrence 19-27 pursuant to the requirements of Millstone Unit 2 Appendix A Technical Specifications, Section 6.9.1.8.i. The report concerns the discovery of conditions not specifically considered in the SAR or Technical Specifications that

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. require remedial action or corrective measures to prevent -'.the existence ,

~ or development of' arr unsafe condftion. "

During a routine plant engineering review, it was detemined that a section of 4" cast iron floor drain piping passing over each of the station batteries was not supported in accordance with design drawings.

The support requirements for this piping included seismic hangers to confom to the plant design criteria for the protection of safety related equipment from damage by non-safety related equipment (seismic 2/1 criteria). The results of an as-built engineering analysis demonstrated that the drain line supports would fail during a design basis seismic event, creating the potential for damage to the station batteries from the unrestrained drain piping.

A concurrent review of other equipment in the battery rooms indicated that sections of the battery exhaust fan ducting for each battery roon did not adequately comply with the seismic 2/1 design criteria. A similar as-built engineering analysis demonstrated the potential for battery danage from portions of the ducting which could become unrestrained during a seismic event.

191003? N1 iO93341

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Mr. Boyce H. Grier U. S. Nuclear Regulatory Commission - Page 2 After discussions with your office, it was concluded that the potential seismic related damage to both station batteries resulted in plant operation per Technical Specification 3.0.3, since conditions were in excess of those addressed in Action Statement b of Specification 3.8.2.3.

Accordingly, preparations were made to proceed to place the plant in cold shutdown within 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Concurrent with the preparations for shutdown, the inadequately supported drain piping and duct work located in the vicinity of each battery were removed. The rmoval of the drain piping and duct work precluded proceeding to cold shutdown.

Any further infomation will be provided in the two week report.

Yours truly,

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J. F. Opeka Station Superintendent Millstone !!uclear Power Station JF0/ECF/llm cc: Director, Office of Management Infonnation and Program Control, Wcshington,D.C.(2) 1093 544