ML20035A138
| ML20035A138 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 03/10/1993 |
| From: | Russo C COMPUTER PRODUCTS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-PT21-92 NUDOCS 9303240138 | |
| Download: ML20035A138 (2) | |
Text
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COMPUTER ~
PRODUCTS pacctss A UTOM ATION March 10, 1993 Document Control Desk US Nuclear Regulatory Commission Washington, DC 20555
Dear Sir:
This letter is official notification in accordance with 10CFR21.21 of a deviation to specification.
Computer Products, Inc. (CPI) has identified a multi-output redundant power supply assembly and a 48 volt redundant power supply assembly, supplied for installation into two nuclear generatihg facilities, which do not meet overvoltage protection specifications as published.
As of the writing of this letter we have determined that the affected revisions have been supplied for installation at:
o Texas Utilities Electric - Comanche Peak, (our immediate customer SAIC, Huntsville, Alabama)
NEQ904-5051-004 - Shipped quantity 2, September 1991.
Also, three revision "B2" units shipped October 1992,.
that are not affected.
NEQ904-5051-006 - Shipped quantity 2, September 1991; shipped quantity 1, April 1992; and shipped quantity 2, October 1992.
o Yonggwang Nuclear Power Plant (YGN) Units 3 &4 (our immediate customer ABB/ Combustion Engineering, Windsor, Connecticut)
NEQ904-5051-004 - Shipped quantity 8, August 1989.
NEQ904-5051-006 - Shipped quantity 8, August 1989.
A continuing investigation, as the result of a Texas Utilities source surveillance, indicates that these redundant power supply systems have an inherent design flaw in the failure protection circuitry; if an overvoltage failure of one of the internal units occurs it may prevent proper operation of the backup unit.
This deviation does not affect the normal operation of the power supply units; however, in a overvoltage failure mode the fail-safe features of the unit will not perform.
This design flaw has been corrected by our supplier, Unipower Corp. in the most current revision through a Engineering Jfg[3 Change Order.
These power supplies, which are purchased by Computer Products, Inc. from Unipower Corp., Pompano Beach, F 247)0 1 9
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are dedicated. class 1E (safety related) by Computer Products.
i The suspect multi-output units can be identified by Computer Products part number NEQ904-5051-004A; however, these units should be further identified by the Unipower part number 098-1055-000, all currently available revisions EXCEPT F
revision "B2".
The suspect 48 volt units can be identified by Computer Products
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part number NEQ904-5051-006, all currently available revisions.
Computer Products,"Inc., as a supplier, does not feel that we.
have the capability to perform an evaluation as to the effect-r this deviation may have regarding whether or not a substantial safety hazard exists.
If the utility (operator) decides that corrective action is required on delivered units, access to the circuitry of the
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internal power supply units is necessary and will require shutdown and removal of the power supply assembly from the system.
Computer Products, Inc. is simultaneously notifying Texas Utilities, SAIC, and ABB/CE of this deviation.
Other non-safety related installations, which are not listed above, will be notified in accordance with computer Products, Inc. set policies.
i Sincerely,
/
,<pc5 i
Clem Russo Vice President of Operations cc:
John Pittman, President Computer Products, Inc., Process Automation Division Dave Chamberlain, Director of Quality Assurance r
Unipower Corp.
jn/CR i
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