ML20010J375
| ML20010J375 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay, Palo Verde |
| Issue date: | 09/25/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| Shared Package | |
| ML20010J373 | List: |
| References | |
| NUDOCS 8109300385 | |
| Download: ML20010J375 (1) | |
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September 25, 1981 Docket Nos. 50-528, 50-529, 50-530 Arizona Public Service Company P. O. RoX 21666 Phoenix, Arizona 85036 Attention: Mr. E. E. Van Brunt, Jr.
Vice President - Nuclear Projects Gentlemen:
The enclosed circular is forwarded for your appropriate action.
No written response to this circular is required.
If you have any questions related to this natter, please contact this office.
Sincerely, Dr.ginal s'gnea by
- d. H. Engelkan R. H. Engelken Director s
Enclosure:
IE Circular No. 81-13 cc w/enclosura:
F. W. Hartley, APS G. C. Andognini, Vice President, Electric Operations 8109300385'010925 PDR ADOCK 05000133 G
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8107230029 IEC 81-13 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 September 25, 1981 IE CIRCULAR NO. 81-13:
TORQUE SWITCH ELECTRICAL BipASS CIRCUIT FOR SAFEGUARD SERVICE VALVE MOTORS
Background:
A common wiring discrepancy between the as-designed and as-installed valve motor control circuitry caused, at least in part, a valve malfunction at two operating boiling water reactors.
In each case, an electrical bypass circuit around the valve-open torque switch on a Limitorque valve operator was not installed as designed.
The intent of this bypass feature is to override the valve open or valve-close torque switch circuits to ensure that full motor torque is applied I
to the valve until it is near full open or full closed. This is to eliminate the chance of the valve stalling out under emergency conditions before it has completed its travel.
Description of Circumstances:
Brunswick Unit 2. During a test of' the reactor core isolation cooling (RCIC)
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system at this facility, in March 1978, the injection valve would not open.
The valve and valve motor were checked, cycled and tested; no problems were identified.
In September 1980, following a. reactor scram, the same valve failed to fully open. An i_nspection of the valve motor control circuitry by the licensee revealed that the electrical bypass circuit wiring around the valve-open torque switch was not installed.as designed. Examination of other RCIC system valves revealed that four of ten, similar torque switch bypass circuits had not been install'ed. The missing electrical bypasses were installed.
Cooper Station --During a test of the residual heat removal (RHR) system at this facility, in December 1980, one of the RHR loop injection line isolation valves would not open.
The problem was reported to be an incorrect closing torque switch setting. However, it was noted and reported, is unrelated to this event, that both Train A and Train B injection valve-open torque switch bypass circuits had not been installed in the valve motor control circuitry as designed.
This discrepancy was corrected.
Recommended Action for Holders of Operating Licenses or Construction Permits:
.1.
Verify-that all valves important to safety, which are re. fired by the design to have torque switch bypass circuits installed, da in fact have these circuits installed.
2.
Verify that 611 applicable electrical drawings correctly reflect these electrical bypass circuits.
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IEC 81-13 September 25, 1981 i
Page 2 of 2 3.
If inspection reveals that required bypass circuits are not installed, installation should be initiated as soon as practicable after the need has been determined.
4.
Establish controls to assure that torque switch bypass circuits are not inadvertently cemoved and that they are restored if they are removed for -
maintenance or test.
No written response to this circular.is required; however, if discrepancies are found, a report may be required by applicable Technical Specifications or other NRC reporting requirements.
If you need additional information with regard to this subject, please contact the Director'of the appropriate NRC Regional Office.
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Attachment:
l Recently issued IE Circulars l
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T Attachment IEC 81-13 September 25, 1981; RECENTLY ISSUED IE CIRCULARS Circular Date of No.
Subject' Issue Issued to 81-12 Inadequate Periodic Test Proce-7/22/81 All power reactor dyre if PWR Protection System facilities with ar.
OL or CP 81-11 Inadequate Decay Heat Removal 7/23/81 All BWR facilities with OL or CP 81-10 Steam Voiding in the Reactor 7/2/81 All power reactor Coolant System During Decay facilities with an Heat Removal Cooldown OL or.CP 81-08 Fo. 'dation Materials 5/29/81 All power reactor facilities with an OL or CP 81-07 Control of Radioactively 5/14/81 All power reactor Contaminated Material facilities with an OL or CP 81-06 Pctential Deficiency Affecting
~4/14/81 All power reactor
'ertain Foxboro 20 to 50 facilities with an Milliampere Transmitters OL or CP 81-05 Self-Aligning Rod End Bushings' 3/31/81
.All power reactor for Pipe Supports; facilities with-an OL or CP
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vi-04 The Role of Shift Technical
~ /30/81-
. All power reactor Advisors and Importance of'.
facilities with an -
OL or near-term OL Reporting Operational Eventsi 81-03 Inoperable Seismic Monitoring ' - 3/2/81-
-All power reactor Instrumentation
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+ fa'cilities with an 0L or ^P
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81-02 Performance of NRC-Licensed 2/9/81 -
All power reactor Individuals While on Duty facilities'(research
& test) with an OL or CP 81-01' Design Problems Involving 1/23/81 All power reactor Indicating Pushbutton facilities with Switches Manufactured by an OL or CP Honeywell Incorporated i