ML19312C372
| ML19312C372 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, McGuire  |
| Issue date: | 05/31/1978 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 7912130902 | |
| Download: ML19312C372 (1) | |
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- Refer Tc, RI7:JPO 50-369, 50-370 3 0- 59, 50-270 50-267 Dul:e Power Company Attn:
Mr. William O. Parker, Jr.
Vice President, Steam Production P. O. Box 2178 422 South Church Street Charlotte, North Carolina 28242 Gentlemen:
The enclosed Circular 78-07 is forwarded to you for information.
If there are any questions related to your understanding of the suggested actions, please contact this office.
Sincerely,
[
- James P. O Reil y Director
Enclosure:
IE Circular 78-07 cc w/ enc 1:
J. C. Rogers, Proj ect Manager McGuire Nuclear Station P. O. Box 2178 Charlotte, North Carolina 28242 M. D. McIntosh, Plant Manager McGuire Nuclear Station P. O. Box 488 Cornelius, North Carolina 28031 J. E. Smith, Station Manager Oconee Nuclear Ststion P. O. Box 1175 Seneca, South Carolina ~
29678 7912130fo%
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UNITED STATES NUCLEAR REGULATORY CO.*eiISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 May 31, 1978 IE Circular No. 78-07 DAMAGED COMPONENTS OF A BERGEN-PATERSON SERIES 25000 HYDMULIC TEST STAND Description of Circumstances:
During functional testing of hydraulic snubbers at a power reactor f acility, test results were adversely influenced by the use of damaged components in the test stand connectors to the snubber being tested.
The following paragraphs are the manufacturer's (Bergen-Paterson) description of the problem together with recoceended proced::res to evoid such problems in the future:
A number of HSSA-3 (Hydraulic Shock and Sway Arrester) Units, 1-1/2" bore x 6" stroke, with 3,000 pound load rating, exhibited nonuniform performance. The bleed rates were erratic and in some instances a structural lockup was observed. A sample of units were disassembled and found to be in proper working order.
Attention was then directed to the testing machine's fixturing. The series 25000 test stand utilizes a 2 pin loading system to simulate octual strut load connections which does not allow transmission of bending moments in the vertical plane.
Unlike the actual strut which employs a ball bushing, the test stand's fixturing is a simplified pin connection.
An inspection of the load pins and bushings during the review of the test fixturing indicated that they were damaged due to a prior. overload condition. These damaged components induced bending moments into the test units which produced mechanical binding between the piston rod and its bearing.
The noted sent type loading condition does not occur on units in service si e all strut assemblies incorporate ball bushings in the cross pin connection at each end of the strut, providing a universal cetion thereby assuring pure axial loading.
Bergen-Paterson recommends that the pinned connections and fixtures of the Series 25000 test stand or other test equipment used for snubber testing be periodically inspected and replaced if indications of damage are noted.
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e IE Circular No. 78-07 May 31, 1978 32rgen-Paterson's 2ecommended inspection frequency should be as follows:
A.
Prior to initial start ef a Test Program.
E.
After each 60 credits of units tested - with credits assigned per the following schedule:
ESSA UNIT SIZE CREDIT 5 3
1 10 1
20 2
30 3
50 5
70 5
Inspection acceptance criteria for Test Fixture Components are:
Cross Pins s'traightness 0.015 in.
Bushings Cylindricity 0.015 in.
Fit
.020 in. Max Diametral While there are a limited number of this specific test stand currently in use, it is considered likely that similar bydraulic snubber test All holders of Reactor equipment may have comparable problems.
Operating Licenses or Construction permits should consider the following items in their review of this matter:
Review the snubber testing device utilized at your facility 1.
to determine if a comparable problem could develop in the mounting fixtures.
Consider the need for a periodic inspection and replacement 2.
of components that could adversely affect the test results.
No written response to this Circular is required.
If your require edditional information regarding this matter, contact the Director of the appropriate NRC Regional Office.
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IE Circular No. 78-07 May 31, 1978 LISTING OF IE CIRCULARS ISSUED IN 1978 Date Issued To Circular Subject of Issue No.
78-01 Loss of Well Logging 4/5/78 All Holders of Well Logging Source Source Licenses 78-02 Proper Lubricating Oil 4/20/78 All Bolders of Reactor OLs or for Terry Turbines cps 78-03 Pack 6ging Greater Than 5/12/78 All Holders of Reactor Ols, cps, Type A Quantities of Fuel Cycle, Tev Specific Activity Priority 1 Material Fadioactive Material and Waste Disposal for Transport Licenses
.78-04 Installation Errors that 5/15/78 All Holders of Reactor OLs or Could Prevent Closing of cps Fire Doors 78-05 Inadvertent Safety 5/23/78 All Holders of Reactor OLs or Injection During cps Cooldown 78-06 Potential Common Mode 5/25/78 All Holders of Reactor OLs or Flooding of ECCS Equip-cps ment Rooms at BWR Facilities i
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