ML19347F817
| ML19347F817 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 05/15/1981 |
| From: | Wells D DETROIT EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, EF2-49-970, NUDOCS 8105260393 | |
| Download: ML19347F817 (2) | |
Text
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8""##'s May 15, 1981 EF2-49,970 Nl os Mr. James G. Keppler, Director Region III U.S. Nuclear Regulatory Comnission 799 Roosevelt Road l
Glen Ellyn, Illinois 60137
Subject:
Interim Report on 10GR50.55(e) Item on Fisher Control Valves
(#37).
Dear Mr. Keppler:
1 The final report on this Fisher Control Valves problem cannot be subnit-ted to you by May 15, 1981, as scheduled. This additional interim report is to provide you with the current status of the evaluation of this prob-lem.
This item was originally reported to Mr. R. Knop of NRC - Pagion III by Detroit Edison's Mr. H.A. Walker, Supervisor - Construction Quality Assurance on December 31, 1980. At that time, it had been determined that there was a problem !.th Fisher Control Valves at the Fermi 2 Site.
Control valves were purchased fran Fisher Controls according to Detroit Edison specifications. Dilring the purchase of additional valves, Detroit Edison Desfgn Engineering determined that cut-off frequencies had not been specified to assure that seismic design of the valves accounted for l
the Fermi 2 peak response frequency. It has been subsequently determined that a design deficiency exists.
Dascription of Deficiency L
l Control valves purchased frau Fisher Controls were specified without pro-viding a cut-off frequency for seismic analysis. In subsequent discus-sions with Fisher Controls, it was requested that Fisher revie.f all Fjsher supplied safety related control valves for minimum resonant frequencies.
Based on this analysis, it was determined that ten (10) valves have natural frequencies belcw thirty-three (33) hz. The resultant stress levels that the actuator bonnet assembly are subjected to during a basis l
event could cause valve failure and pressure integrity rupture.
Action Taken An investigation has been initiated to determine if the control valves can be qualified by determining the natural frequencies of the piping systems within which these valves are installed. A time history analysis will be perfomed on each pipe system configuration containing the control valve
- '9r 6t6 8105260 M3 3
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Mr. James G. Keppler, Director May 15, 1981 Page Two EF2-49,970 to establish the natural frequency of the system. If the natural frequerg l
of the control valve is established to be above the piping system natural frequency, the valve will be ac. we as qualified. 1: parallel to the engineering investigation, the specifications will be uv3ated and quota-tions for new valves will be sought and purchase initiated as maary.
l Another report m the item, either interim or final, is Wiled to be sent to you cm or before Septarber 11, 1981. If you have questions con-cerning this matter, please contact Mr. H.A. Walker, Supe.rvisor - Canstruc-tion Quality Assurance.
Very truly J
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DAW / w /pn ec: Mr. Victor Stello, Jr., Director Office of Inspection and Enforcernant Division of Reactor Inspection PWcus 1
U.S. Nuclear Regulatory Ccamission Washington, D.C.
20555 Mr. Bruce Little, Resident Inspector U.S. Nuclear Regulatory Cm mission Resident Inspectors Office 6400 North Dixie Highway Newport, Michigan 48166 l
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