ML20044G501
| ML20044G501 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear, Columbia, Bellefonte  |
| Issue date: | 05/26/1993 |
| From: | Taylor J BWR OWNERS GROUP |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-PT21-93 JHT-93-127, NUDOCS 9306030214 | |
| Download: ML20044G501 (8) | |
Text
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BW BGWNUCLEAR TECHNOLOGIES n-JHT/93-127 3315 OldForest Road May 26, 1993 P.O. Box 10935 Lynchbury VA 24506-0935 Telephone:804-385-2000 Telecopy: 804-385-3C53 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Potential Safety Concern Regarding Negative Reference Power Supply Gentlemen:
The purpose of this letter is to advise you of Buffer Amplifier Modules manufactured by Bail a concern regarding containing a suspect Negative Reference Power Supply th t safety implications.
ey Controls Company a
may have The concern arose as the result of a Controls Company dated January 26, notification from Bailey Supply circuit board assembly in Buffer Amplifiadvised tha 1993, copy attached.
Bailey e Reference Power When power'was applied to the assembly it did er and Test Modules.
the module to malfunction.
These modules not operate, causing related applications.
are concern is found in the Bailey letter. Additional information on the nature of the used in safety-BWNT also learned from Bailey that the probl Reference Power Supply circuit board was em with the Negative testing.
during checkoutThere have been no reports that this problem h d discovered during lab of production modules a
occurred root cause of problem is or from any utility.
The the circuit board circuitry.
apparently in the design of the BWNT believes that the Test Modules are not a potential safe concern.
Although the Test Modules are and are installed in the cabinet function. powered up, they are not actively The type of failure the Negative Reference P involved in the trip undergoes is a go/no-go failure and not an improper v lt Therefore, the use of these modules would not result in a ower Supply o
miscalibration of the active modules in a trip stri age output.
ng.
The Buffer AmplifLer Modules of concern wer replacement parts Entergy Operationn.in February 1992 by BWNT to the ANO-1e supplied as spare /
Amplifier Modules of concern vue also suppli dA preliminary review indicat unit of Units of TVA and to the WNP-1 unit of Washin t to the Bellefonte Buffer e
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i U.S. NRC JHT/93-127 May 26, 1993 i
1 Page 2 e
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. Supply System.
TVA' intends to. resume construction of :the Bellefonte: units and the WNP-1 unit is in a-deferred status of -
construction.
l BWNT has not performed an.. evaluation : to determine the safety; significance with respect to the. Buffer-Amplifier: Modules at the' t
applicable plants,~or if the concern is-reportable under 10CFR21.
BWNT has therefore notified the applicable utilities of the concern for their evaluation.
BWNT plans no further evaluation ' of the concern unless requested and authorized by the utilities.
BWNT has - not performed an evaluation for reportability under 10CFR21 concerning..the. Buffer -Amplifier' Modules due:.to the'
~
following reasons:
1.
BWNT has not positively determined (applicable to'TVA/WPPSS only) whether the Buffer Amplifier Module in question was in fact supplied to TVA and-WPPSS in the f time frame. cited by Bailey Controls Company; and if so, exactly which applications they were supplied for.
2.
BWNT does not have positive information that the-Negative Reference Power Supply with Part No.- ' _6635436Al is in: fact.
installed in.the Buffer Amplifier Modules 'suoplied to the
.i utilities. As stated by Bailey in their letter,.the utilities.
are. advised to inspect the modules' to determine if ' that
[
particular Part No..is present.
It is-possible that a Reference. Power Supply with a different part-number is present.
3.
Bailey advises in their letter that the condition (i.e., the power supply circuit board assembly failure to operate when power was applied) may not appear in all modules that contain l
the assembly.
BWNT has no positive information that, even if t
the subject power supply Part No. is present in the. modules l
supplied to the utilities, that they will fail to operate as described by Bailey.
4.
BWNT has not determined the safety consequences of the failure I
of the power supply circuit board.
Determination of the safety consequences first requires an analysis of the effect of failure of this circuit board on the performance of the Buffer Amplifier Module..This analysis is dependent on both i
the module design and:its calibration. Calibration-is done in-the field by plant personnel,-and BWNT has no information on plant-specific-calibration procedures.
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4 U.S.
NRC JHT/93-127 May 26, 1993 4
Page 3 r
This informational letter to the NRC is not a notification under 10CFR21.
You may contact me at 804/385-2817 or Mr. David Mars at 804/385-2852 if you have any questions concerning this matter.
4 truly yours, J.
H. Tayle Manager Licensing Services JHT/bcc-Attachment cc:
C.R.
Gaines, Entergy Operations, Inc.
R.
D. Wells, Tennessee Valley Authority L.
C.
Oakes, Washington Public Power Supply System E.
E. Mahoney, Bailey Controls Company 4
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r-i, j,H.voiOH
! ailey Controis Company M9 4 E B
a division of Elsag Bailey, Inc.
26 February,-1993 B E W Nuclear Service Company P.O. Box 10935 l
Lynchburgh, VA 24506-0935 Attention:
Mr. J. H. Taylor Manager, Licensing Services
Subject:
Notification of Potential Deviation Daar Mr. Taylor:
Bailey Controls Company has long been a_ leader in the supply of control and safety system components for the nuclear industry.
The 1
safety and quality-of nuclear qualified products ~are of paramount
(-concern to Bailey.
Our' designs and the manufactured or purchased (laterials of which they are constructed are carefully scrutinized to.
assure that we maintain quality and performance as we continue to support the needs of our nuclear utility' customers.
On 15 January 1993, we observed an irregularity in a negative reference power supply circuit board assembly.
The function of the assembly is to provide a calibrated negative reference of -10.0 or -
11.5 Volts for use within a module.
When power was applied to the assembly it did not operate.
The output remained at or near zero Volts, causing the module to malfunction-The assembly is Bailey part number 6635436A1.
It may be used in modules in type 88_ nuclear i
scfety systems.
Bailey's report under 10 CFR 21 is included as an attachment to this letter.
1 Only a few modules were built with this assembly.
The condition
)
may not appear in all modules that contain the assembly.
For this reason, we are unable to precisely determine the importance of this condition for each of our customers.
Accordingly, we have classified this condition as a potential deviation. As you are aware, this cl'assification does not require a notification to be sent to the NRC.
Wa do urge you, however, to review your system to determine if any-of these modules are in use in critical applications and take appropriate corrective action as suggested in the attached report.
An attachment lists module part numbers and the dates they were shipped to your
- facility, b
29801 Euclid Avenue
- Wickliffe, Ohio 44092 U.S.A. Phone (216) 585-0500 Fax (216) 585-8756
4 d
Bailey is notifying its customers of this condition as a result of our commitment to Bailey's Total Quality Assurance Program.
Bailey stands ready tio supply any support that you may need in evaluating the significance of this change.
Please feel free to contact either Frank Sillag (216) 585-5711 or myself (216) 585-7832.
l i
Very truly yours,
/
E. E. Mahoney Director, Quality Assurance n
4 l
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1 l
s I '.
This condition applies to:
i Negative reference power supply assemblies part number 6635436A1.
The assembly was created in October of 1983.
The assembly may-be r
found in modules of the part numbers listed above.
These modules j
are used in type 88_ nuclear safety systems supplied by the j
Bailey Controls Co.
i l
Corrective action:
Bailey controls Co. is providing this notice to its customers.
j The negative reference. power supply assambly has been redesigned j
to assure that the circuit will start when power is applied.
The replacement part numbers are 6635436C1 for -10 volt applications and 6635436A2 for -11.5 Volt applications.
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our customer is advised as follows:
4 i
Applications of modules of the part numbers listed above should l
be reviewed to determine the potential consequences of the l
reported condition.
Suspect modules should be inspected to j
determine if negative reference power supply assembly part number 6635436Al is present.
The safety implications, if any, should be evaluated and appropriate action taken.
It is recommended that negative reference power supply assambly part number 6635436Al be 3
j replaced.
)
Bailey Controls Co. remains committed to serving the needs of our j
nuclear utility customers as well as our total worldwide customer base.
We apologize for any inconvenience this condition may_cause you.
Bailey stands prepared to provide any support you'may require in the evaluation of this condition.
We trust that you will continue to j
look to Bailey for your continuing control needs.
Please direct questions or comments regarding this notification to Ed Mahoney (216) i 585-7832 or Frank Sillag (216) 545-5711.
t o
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i-e.
l SAILEY CONTROLS COMPANY Safety consera Report SCR-068 Rev. Original 26 February 1993
)
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10CFR21 report issued by:
i Mr. Edward E. Mahoney l
Director of Quality Assurance Phone:-
(216)- 585-7832 Fax:
(216) 585-5090
)
Bailey Controls Co.
i 29801 Euclid Ave.
Wickliffe, OH 44092 l
4 Items supplied:
l J
Module Part P=her Descriation Buffer Amplifier Module 1
l 6421470331 _ _ _ _ _
Temperature Test Module-6623825A1 Power Range Test Module 6625215F1 Power Range Test Module i
6625215F2 Power Range Test Module l
6629214A1 Power Range Test Module l
6629214A2 Universal Test Module Universal Test Module l
f 6635140A1 I
663514012 suhass==hiv Part r=%r Description 4,
Negative Reference Power supply l
6635436A1 This subassembly nay be used in the
~
modulee listed above.
Items supplied by:
Bailey controls Co.
t 29801 Euclid Ave.
j Wickliffe, OH 44092 i
Potential Deviation:
The reference voltage source circuit may not turn on or start The result is an output near l
properly when power is applied.This is a random condition that any appear w zero volta dc.
power is first applied to a module or when power is restored j
following an interruption.
This condition will not appear spontaneously during normal operation.
j i
This condition came to our attention on:
15 January 1993 i
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SAFETY CONCERN REPORT SCR-068 4
Notification Address:
Mr. J. R. Taylor Manager, Licensing services 4
I B&W Nuclear Service-Co.
P.O. Box 10935 Lynchburgh, VA 24506-0935 J
Order Address:
Babcock & Wilcox Co.
NPDC 3117 ODD FELLOWS RD LYNCHBURGH VA 24501 Item Quantity shipping Order #
Data shipped 6621670BE110321 2
37920P10 04 Feb 92 f
,