Bulletin 73-04: Defective Bergen-Patterson Hydraulic Shock Absorbers Information
ATOMIC ENERGY COMMISSION
DIRECTORATE OF REGULATORY OPERATIONS
REGION II - SUITE 818
230 PEACHTREE STREET, NORTHWEST
ATLANTA, GEORGIA 30303
August 17, 1973
The reports of your action in response to Regulatory Operations Bulletin
No. 73-3, dated July 27, 1973, and other information concerning Bergen-
Patterson hydraulic shock absorbers, indicate that additional action is
Enclosed is Regulatory Operations Bulletin No. 73-4 which provides you with
additional information and lists certain actions 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 any questions concerning this matter, please contact me.
Norman C. Moseley
Regulatory Operations Bulletin
No. 73-4, Dated August 17, 1973
Bulletin No. 73-4
Date: August 17, 1973
DEFECTIVE BERGEN-PATTERSON HYDRAULIC SHOCK ABSORBERS
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-Patterson 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-Patterson 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
1. Schedule and conduct a reinspection of Bergen-Patterson hydraulic shock
absorbers installed in safety related systems following approximately 45 days
and no longer than 90 days after the plant has been at operating temperature
subsequent to the inspection performed as requested in RO Bulletin 73-3.
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2. The inspection should include:
a. Determination of condition of seals.
b. Verification of overall integrity of shock absorber assemblies.
c. Examination for loss of fluid, fluid leaks, and other signs of 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-Patterson hydraulic shock absorbers.
4. Provide this office with a prompt telephone report of the significant
findings of this reinspection. If defective shocks 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 within 30 days following the completion of the
5. The written report should include:
a. As appropriate, a description of the mode of failure, corrective action
and tests performed to determine the adequacy of the repair.
b. A description of the program for the development and subsequent
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-Patterson
hydraulic shock absorbers have been resolved.
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