ML20098E186
| ML20098E186 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 05/29/1992 |
| From: | Kovach T COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9206020017 | |
| Download: ML20098E186 (4) | |
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O 1490 Opus Placs Downers Grova, Illinois 60515 May 29,1992 U.S. Nuclear Regulatory Commission i
Washington, D. C. 20555-Attn:
Document Control Desk
Subject:
Byron Nuclear Power Station Unit 1 and 2 i
Respo,'.se to Unresolved items Inspection Repod 50-454(455)/92000-NRC Docket Number 50-454 and 50-455 i
Reference:
B. Clayton letter to Cordell Reed dated-March 30,1992, transmitting Inspection Report 50-454(455)/920061 Enclosed is Commonwealth Edison Company's (CECO) response to two ;
Unresolved items which were transmitted with the reference letter and Inspection-Report.
The Unresolved items concerned work performed' not addressed by station -
documents and methods.used to verify operability testing of check valves in systems open to the containment atmosphere where the process medium is air.
L If there are any questions or comments regarding this' response, please-contact Sara Reece-Koenig,-- Compliance Engineer, at 708/515-7250.
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. Sincerely,
$ Wg T.J. Kovach -
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L Nucleari.lcensing Manager Attachments I
cc:
A. Bert Davis, Regional Administrator - Region Illi A. H. Hsia, Project Manager, NRR-'
W. J. Kropp, Senior Resident Inspector, Byron.
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COMMONWEALTH EDISON COMPANY RESPONSE TO INSPECTION REPORT 454(455)/92006 UNBESOLVEDlTEMA55L9200B-02 While witnessing the replacement of a pressurizer pressure transmitter (loop 455) in accordance with surveillance procedure 2 BIS 3.1.1-206, the inspector noted that cap -
screws for a clamp on a Unistrut used to suppor? a conduit feed to the transmitter had been loosened. The inspectors did not find any reference in the surveillance procedure or the Nuclear Work Request (NWR) 885936 to the loosening and/or removal of the Unistrut clamp during the replacement of the transmitter. Further discussion with the maintenance department determined that there was torquing requirements for the cap screws for the clamp. The inspectors determined that the surveillance procedure, 2 BIS 3.1.1-206, had been recently revised to include the new opt.on of replacing i
transmitters by disconnecting the conduit feeds to the transmitter. The previous method of replacement using a Raychem splice was still addressed in the procedure.
The inspector's were concerned that the loosening of the clamp on the Unistrut, which wat not addressed in the surveillance procedure or NWR, was performed without the restoration requirements for torquing the cap screws. Pending further review by the (DRP). To facilitate a timely closure of this item, a written response i(455/92006 NRC and the licensee. this matter is considered an Unresolved Kem s requested that addresses the results of the licensee's review with particular emphasis on work performed not addressed by station documents, such as, NWRs or surveillance procedures.
BESP_QMSE During development of the procedure BIS 3.1.1-206, revision, allowing replacement of a transmitter by removal of the Seal Connector Assembly, a mock up was used to validate this new replacement method. What was not known at that time, was that some installations require that the conduit support be removed in order to remove the I
transmitter, others do not.
The action taken by the technician in removing this clamp was within the scope of the work directions specified by the procedure. However, the procedure did not specify torque values for reinstallation.
The work package was returned to the Work Analyst for revision to include specific l
torque values. During this review it was recognized that this situation may also exist for the three other procedures that were just revised to make use of the Seal Connector l
Assembly.
Procedures BIS 3.1.1-203, BIS 3.1.1-204, BIS 3.1.1-205 and BIS 3.1.1206 and their accompanying test report packages were revised to incit de torquing requirements to be used if the conduit support is removed. ZNLD/1826/2
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o-An evaluation is being performed by the Assistant Superintendent of Maintenance and the Maintenance Masters to determine the scope of work to be included in
. maintenance procedures. Items to be considered willinclude craft capabilite, training, regulatory requirements and safety. This evaluation and implementation of corrective -
actions will be completed by September 30,1992.
In the interim, a memo has been issued to Station and ENC personnel describing the concern and to heighten the level of awareness for performing work not detailed in a procedure.
UNBESO13RREEht45M920003-03 During a review of surveillance procedure 1 BIS 6.4.1-003, the inspectors notad that the procedure, in addition to the functional test of the Hydrogen Monitor (HM), also verified the operability of containment isolation check valve 1PS231 A located in the discharge line in accordance with the IST program and Technical Specification (TS). The check valve,1PS231 A, was determined operable if flow through the HM system was noted as 3 SCFH on the HM installed flow meter. Since the discharge line was capped and the leak in the HM system was u 3 stream of the check valve, there was no flow through the -
check valve between Novem 3er 2,1991 and February 19,1992 when the cap was discovered on the discharge line. Therefore the performance of surveillance 1 BIS 6.4.1-003 was not verifying operabilih of check valve 1PS231 A whenever the surveillance was performed between November 2,1992 and February 19,1992.
Surveillance 1 BIS 6.4.1-003 was performed monthly with the TS and IST program requiring verification of operability of check valve 1PS231 A, on a minimum frequency of every quarter. With the pipa cap inadvertently placed on the discharge line of Train A of the HM system on November 2,1991, the last time surveillance 1 BIS 6.4.1-003 was performed without the pipe cap installed was November 1,1991.- Subsequent to discovering the pipe cap on the discharge line, the licensee pen *ormed survaillance 1 BIS 6,4.1-003 after the pipe cap was removed. The performance of this servoillance adequately verified the operability of valve 1PS231 A and was pedormed within the required frequency (plus the allowed 25%) since the last successful performance of the surveillance on November 1,1991. Based on this event the inspectors considered surveillance procedure,1 BIS 6.4.1003, as inadequate to verify cperability cf check valve 1 PS231 A in accordance with TS and the IST program Pending fu:ther review by the NRC and licensee, this matter is considered an Unresolved item (454/92006-03 (DRP)). To facilitate a timely closuro of this item, the inspectors reouest a written response from the licenses that discusses the methnds utiiized to verify operability of:
other check valves in systems opened to the containment atmosphere where the process medium is air. ZNLD/1826/3 i
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4 BE.SP_QNSE Procedures 1/2B!S 6.4.1002,003, " Calibration of Hydrogen Monitor," will be revised to :
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- include a requirement to verify check valves 1/2 PS231 A/B fully stroke _-
A review of all check valves in the Byron Station IST, ASME program was conducted.
From this review, it was determinC that the only other check valves in systems opened -
to the containment atmosphere whn air as the process medium and which receive IST I
operability tests are 1/2PR002G, H and 1/2PR032.1 None of these valves has a safety _
function in the open direction which'would require that they receive a check valve full flow test such as the one performed for the 1/2PS231 A,B valves in surveillance 1/2 BIS 6.4.1-002,003. The only IST operability tests required for the _1/2PR002G, H and 1/2PR032 valves are backflow and seat leakage tests.- Each valve is tested; separately,.
proving each Individual valve is capable of performing its IST function.-
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