ML20003G055

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Responds to IE Bulletin 81-01, Surveillance of Mechanical Snubbers. Licensee Identified Seven Accessible Mechanical Snubbers Installed on Sys Required for Safety.No Addl Inc Mechanical Snubbers in Storage
ML20003G055
Person / Time
Site: Fort Calhoun Omaha Public Power District icon.png
Issue date: 02/27/1981
From: William Jones
OMAHA PUBLIC POWER DISTRICT
To: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
IEB-81-01, IEB-81-1, NUDOCS 8104280139
Download: ML20003G055 (2)


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.y- 4 Omaha Public Power District 1623 HARNEY a OMAMA, NE8RASMA 68102 s TELEPHONE S36 4000 AREA CODE 402 February 27, 1981 To ADM/DMB:

PDR f~ LPDR Mr. K. V. Seyfrit, Director i U. S. Nuclear Regulatory Commission 6 Office of Inspection and Enforcement m 8[ -

ADM/RSB Region IV 2 4 bb r2 611 Ryan Plaza Drive, Suite 1000 D u,/3,IPR %

Arlington, Texas 76011 ed!@^rou g b

Reference:

Docket No. 50-285 ,

Dear Mr. Seyfrit:

Omaha Public Power District received IE Bulletin 81-01, dated January 27, 1981, regarding surveillance of mechanical snubbers. Item 1 of the bulletin required all licensees to perfonn operability tests by February 26, 1981, on all accessible mechanical snubbers manufactured by International Nuclear Safeguards Corporation (INC) and installed on safety-related systems. Also, INC mechanical snubbers in storage were to be tested. The discussion below details the District's plans re-garding INC mechanical snubbers. This program was discussed by tele-phone between Messrs. Patterson and McIvor of Omaha Public Power Dis-trict and Mr. Doyle Hunnicutt of your staff on February 19, 1981.

The District identified seven (7) accessible mechanical snubbers installed on systems required for safety at the Fort Calhoun Station.

One of the snubbers, installed on the shutdown cooling system return line, has been replaced with a hydraulic snubber. This mechanical snubber was operable at the time it was removed. Five~(5) of the remaining six (6) snubbers are installed on the two-inch steam supply line to the auxiliary feedwater (AFW) turbine-driven pump. The other snubber is attached to a valve operator on a non-class portion of the main steam line. This snubber was included, however, since it is the first snubber past the class boundary. A visual examination of these six (6) snubbers has been performed, as well as an in-place manual verification that each snubber has freedom-of-movement; i.e., not frozen. All six (6) snubbers were determined to be operable. There are no additional INC mechnical snubbers in storage.

The Fort Calhoun Station AFW system was not originally designed or constructed as a safety grade system. As a long term effort, an upgrade

, of the AFW system to safety grade criteria has been in progress and will be fully implemented during the 1981 refueling outage. This effort was approved by the Commission's letter and safety evaluation dated February 2, 1981. Accordingly, consistent with the District's program for upgrading the Fort Calhoun Station AFW system, the District will reevaluate the seismic design of the steam supply line to the AFW turbine-driven pump.

The INC snubbers will be removed and hydraulic snubbers added as re-Q quired.

81042 8 0 V*R

Mr.'X. V: Seyfrit February 27, 1981 Page Two The District's proposed actions will resolve all safety concerns regarding accessible INC snubbers installed at the Fort Calhoun Station.

Bulletin requirements regarding inaccessible INC mechanical snubbers and other makes of mechanical snubbers installed in safety-related systems will be addressed by separate letter.-

Sinc,erely, i Ifu Q 'jUO J -

W. C. Jdnes Division Manager Production Operations WCJ/KJM/TLP:jmm cc: U. S. Nuclear Regulatory Commission .,

Office of Inspection and Enforcement Washington, D.C. 20555 LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.

Washington, D.C. 20036 l

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