ML20127H439
| ML20127H439 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 08/17/1973 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Wachter L NORTHERN STATES POWER CO. |
| References | |
| IEB-73-03, IEB-73-3, NUDOCS 9211180513 | |
| Download: ML20127H439 (3) | |
Text
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1 ATOMIC ENERGY COMMISSION
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Y DIRECTORATE OF REGULATORY OPERATIONS to REGION lit bs d "
799 ROOSEVELT ROAD m gpwong GLEN ELLYN ILLINOIS 60137 O t ti 85s-1650 August 17, 1973 Marthern 8tates Power Company Docket No. 50-263 ATTE: Mr.14e Weehter, Visa President Power Producties and System Operation 414 Nicollet Hall Minneapolis, Minnesota 55401 Gentlemen The reports of your action in response to Regulatory Operations Bulletin No. 73-3, dated July 27, 1973, and other inforastion concerning Bergen-Paterson hydraulic shock absorbers, indicate that sdditional action is advisable.
Enclosed is Regulatory Operations Bulletin No. 73-4 whi:;h provides you with additional information and lists certain actiona that appear appropriate on a timely basis. The Directorate of Licensing currently is evaluating the need for a continuing surveillance program for hydraulic shock absorbers.
You are requested to take the action shown under ACTION INDICATED in the enclosed Regulatory Operations Bulletin No. 73-4, dated August 17, 1973.
Should you have questions concerning this matter, please contact me.
Sincerely.
Boyce H. Crier Regional Director Enclosure 30 Bulletin 73-4 bcct RO Files DR Central Files PDR Local PDR OGC, Beth, P-506A 9211180513 730817 PDR ADOCK 05000263 G
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August 17, 1973 Directorate of Regulatory Operations Bulletin 73-4 DEFECTIVE BERGEN-PATERSON HYDRAULIC SHOCK ABSORBERS INFORMATION Reference is made to Regulatory Operations Bulletin 73-3, dated July 27, 1973, entitled DEFECTIVE HYDRAULIC SHOCK ABSORBERS AND RESTRAINTS which provided information on known problems with hydraulic shock absorbers and which requested actions, including inspections of installed' hydraulic shock absorbers, by certain utilities.
The compiled results of these inspections.of Bergen-Paterson shock absorbers, based on telephone reports from affected licensees to the five Regional Offices of the Directorate of Regulatory Operations, reveal that a large percentage of installed Bergen-Paterson hydraulic shock absorbers were not fully operational. In addition, preliminary information indicates that routine repairs, replacing defective seals and filling hydraulic oil reservoirs may not be an adequate long range solution to this problem.
There is also some indication that deterioration of the affected hydraulic shock absorbers can occur over a relatively short period of time (less than 90 days).
ACTION INDICATED 1.
Schedule a. reinspection of Bergen-Paterson hydraulic shock absorbers installed in safety related systems to be conducted approximately 45 days and no longer than 90 days af ter the plant has been at operating temperature subsequent to the inspection performed as requested in R0 Bulletin 73-3.
2.
The inspection should include the following:
(
a.
Determination of condition of seals.
I b.
Verification of overall integrity of shock absorber assemblies, Examination for loss of fluid, fluid lerks, and other signs of c.
distress.
d.
Recording of piston rod extension and fluid level indicator positions.
- 3.. Inform this office of the planned date for reinspection of the Bergen-Paterson hydraulic shock absorbers.
1 t
2-4.
Provide this office with a prompt telephone report of the significant i
findings of this reinspection.
If defective shock absorbers are identified, a written report should be submitted to this office within 10 days following completion of the inspection; if no defective shock absorbers are identified, the' written report should be submitted j
vithin 30 days following the completion of the inspection.
S.
The written report should include the following:
a.
As appropriate for each defective shock absorber identified, a description of the mode of failure, corrective action and tests performed to determine the adequacy of the repair.
j b.
A description of the program for the development and subsequent i
installation of a-permanent modification to the hydraulic shock absorber installation to assure proper operation. The description should include the technical basis for the conclusion that deficiencies in the Bergen-Paterson hydraulic shock absorbers have been resolved.
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