ML19290C120

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Requests Extension to 800111-18 of Schedule for Insp of Inaccessible Piping Per IE Bulletin 79-14.Insp of Accessible Areas Produced Low Number of Discrepancies
ML19290C120
Person / Time
Site: Fort Calhoun Omaha Public Power District icon.png
Issue date: 10/15/1979
From: William Jones
OMAHA PUBLIC POWER DISTRICT
To: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
IEB-79-14, NUDOCS 8001090504
Download: ML19290C120 (3)


Text

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E A Omaha Public Power District 1623 MARNEY O M A N A, NE8RASKA 68102 TELEPHONE 536 4000 AREA CODE 402 October 15, 1979 Mr. K. V. Seyfrit, Di rector U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region IV 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Reference:

Docket No. 50-285

Dear Mr. Seyfrit:

The Omaha Public Power District submitted a response, dated August 31, 1979, to IE Bulletin 79-14, wherein results of inspections of accessible piping at the Fort Calhoun Station were reported. Based upon the results of these inspections and in consideration of the justification herein pro-vided, the District respectfully requests the Commission to grantan exten-sion to the Bulletin 79-14 schedule requiring inspection of " inaccessible" piping in October 1979. Rather, the District proposes to perform the inspection seventy-five (75) days later, during the next refueling outage, scheduled to commence sometime between January 11 and 18.

Inspections of accessitile safety-related redundant and non-redundant systems, for confontance to seismic analysis input information, demonstrated a lov. number of discrepancies. These discrepancies totalled 104 out of 827 inspection elements; one related to pipe-run geometry and the rest related to piping support design, location, and clearance. Twelve of these discrepancies were corrected in the field. The remaining discrepancies were referred to the District's Architect / Engineer for evaluation in accordance with Item 4 of the Bulletin. As of this writing, 81 discrepan-cies have been evaluated in detail. Six of these have been determined to affect system operability and have either been corrected or are being corrected on an expedited basis. Since a large number of these discrepan-cies do not require corrective action, it is believed that they may have been approved field changes during construction; however, the District has no records to substantiate this.

Cause to permit extending the inspection of inaccessible piping is further provided by the mutual interest of the District and Staff in keeping per-sonnel radiation doses as low as reasonably achievable. Performance of these inspections during a refueling outage, as opposed to a mid-cycle shutdown, assures that radiation exposures will be kept to an absolute 1728 264 8 0 010 9 0 5 0V k

Mr. K. V. Seyfrit October 15, 1979 Page Two minimum. The inspections require close personal contact with piping systems carrying radioactive fluid streams. Performance of the inspec-tions during a refueling outage would pemit draining or flushing of some highly radioactive piping, as well as pemit enough time for decay of short lived radionuclides. In addition, airborne radioactivity con-centrations are expected to be lower during a refueling outage. Perform-ance of inspections in a less radioactive environment also enhances the quality of the examinations perfomed.

Finally, extending the inspection schedule by approximately seventy-five (75) days is not expected to, in any way, jeopardize the health and safety of the public because the possibility of a seismic event occurring within this period of time is extremely remote. The Fort Calhoun site lies in a region of low seismic activity. Since the middle of the 19th century, from the first historical record of earthquake occurrence in the area, oniy 12 shakes with epicentral Modified fiercalli Intensities of V or greater have occurred within 200 miles of the plant site, and very few of these had sufficient intensity to cause any structural damage. No damaging earthquakes have ever been reported within 50 miles of the site. Based upon historical evidence, it appears that the site will not experience damaging earthquake motion. (

Reference:

Fort Calhoun Station Unit No. 1 FSAR 5 2.4.)

In view of the foregoing information, the District firmly believes that there is just cause to grant the proposed extension without causing any ,

deterioration in the level of safety at the Fort Calhoun Station. The extension would provide for an enhanced quality of examinations and con-tinued availability of the station. The Ccmmission is asked to provide a determination on this request as early as possible, since the District is currently scheduled to shut down for required inspecticns on October 26, 1979, and arrangements for equipment and manpower must be made in the near future. The District's staff is obliged to discuss this matter at your request.

Since_rf, y,

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1(1 W. C.

/Nb ones Divisi n Manager Production Operations WCJ/KJM/BJH/lp cc: Mr. Victor Stello, Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 1728 265

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Mr. K. V. Seyfrit October 15, 1979 Page Three cc: Mr. Robert W. Reid, Chief Director of Nuclear Reactor Regulation Operating Reactors Branch No. 4 U. S. Nuclear Regulatory Conmission Washington, D. C. 20555 LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N. W.

Washington, D. C. 20036 1728 266