ML20058L631
| ML20058L631 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 08/05/1976 |
| From: | Wachter L NORTHERN STATES POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-76-06, IEB-76-6, NUDOCS 9105300362 | |
| Download: ML20058L631 (1) | |
Text
BGBUD e#&
NORTHERN STATE 5 POWER COMPANY I
M I N N E A PO LI B. M ' N N F C OT A 55401 August 5, 1976 i
Mr. James G. Keppler l
Director - Region 111 Office of Inspection and Enforcement United States Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
MONTICELLO NUCLEAR GENEPATING PLANT Docket No. 50-263 License No. DPR-22 In accordance with Items 4 and 6 of IE Bulletin No. 76-06, the following information is submitted:
1.
The insulation on our safety-related diaphragm-operated relief valves is installed in accordance with the current recommendations of the valve vendor; i.e., there is no thermal insulation installed on or covering the air actuators of these valvcs.
2.
Our maintenanct procedure used for the disassembly and inspection of these valves includes instructions for inspection of the subject diaphragms.
3.
The valve vendor (Target Rock Corporation) advises that the diaphrages will not deteriorate while in storage and have an indefinite shelf life.
They do, however, recomnsend that the diaphrages be replaced after five years of service life. We have determined that the three oldest diaphrages presently installed have been in service for approximately 5 1/2 years.
These diaphrages will be replaced prior to or during the next refueling outage.
Bellofram Corporation (the manufacturer of the diaphragm) has advised us that a service life of 7 or 8 years would be expected with operating temperatures under 2000 F as in our installation. The safety-relief valve surveillance procedure has been revised to require replacement
,of the diaphrages in accordance with the vendor's recommendation.
Yours very truly, c
D " 28g M n ggggs, 39#4 L. J. Wachter Vice President - Power Production and System Operation cc:
Mr. Victor Stello Mr. G. Charnoff Minnesota PollutJon Control Agency Attention:
Mr. J. W.
Terman
/
NRC Of fice of Inspection and Lnf orcement
'1 Washington, D.C.
f i
AUG 9 1976
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