ML20037B052
| ML20037B052 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/09/1978 |
| From: | Reed C COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20037B051 | List: |
| References | |
| NUDOCS 8009030758 | |
| Download: ML20037B052 (8) | |
Text
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V Ons First National Plaza. Chicago. I:hnois Address Reply to: Post Office Box 767 Chicago, lilinois 60690 January 9, 1978 Mr. James G. Keppler, Director Directorate of Inspection and Enforcement - Region III U.S. Nuclear Fegulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Subject:
Dresden Station Units 1, 2 and 3 Response to IE Inspection Report Nos. 30-10/77-35, 50-237/77-32, and 50-249/77-30 NRC Docket Nos. 50-10/237/249 Reference (a) :
J. G.
Keppler letter to B.
Lee, Jr.,
dated Decembcr 16, 1977.
Dear Mr. Keppler:
Attached to this letter is Commonwealth Edison's response to four items of noncompliance identified in Appendix A of Reference (a).
Three of the four items of noncompliance in the inspection report are related to the station procedure for removing equipment from service.
The fourth item of noncompliance is the resuir of an inadequate procedure.
Earlier in 1977, Dresden Station manage-ment began a review of the Dresden Procedure DAP 3-5, which implements the Commonwealth Edison Company procedure for removing equipment from service.
During this review, aspects of preparing, establishing, and clearing equipment outages were examined.
An experienced Maintenance Department Foreman was released from his normal duties for a one-week period to make the first-level review, and his comments have received additional reviews by station upper management.
The major finding of his review pointed out the need for additional awareness and understanding by all station eersonnel involved with the Out-of-Service Procedure, with the details of the Commonwealth Edison Company Order on ot -of-service procedures, and the Dresden bnplementing procedure DAP 3-5.
In December, 1977, the Station Superintendent requested the Training Department to prepare a retraining program for all applicable Dresden personnel.
Additionally, he requested a thorough review of the implementing procedure DAP 3-5.
The station retraining 7N 8000030 t
Commonwealth Edison Mr. James G.'Keppler January 9, 1978 program has now been prepared and is scheduled to begin in late January.
The revision of the implementing procedure has also been prepared and is undergoing station review.
The revised procedure will address steps to ensure that equipment outages are properly prepared and required functional tests are completed when equipment is returned to service.
As a result of additional difficulties experienced with removing equipment from service in December, a special investigative task force has been established to review, as part of their investigation, the application of the out-of-service procedure at Dresden.
This task force consists of the Division Manager of Nuclear Stations, Compliance Administrator, Corporate Station Nuclear Engineering Department Manager, Corporate Station Electrical Engineering Department Manager, Assistant Superintendent of Braidwood Station, and the Dresden Statica Superintendent.
Additional corrective action to prevent recurrences sLailar to
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those mentioned in this inspection report must await the results of that investigation.
As an interim measure, all equipment outages which 1
affect either safety-related or technical specification related equipment will be independently and physically verified to ensure the proper removal and return to service of the equipment.
These redundant inspections will be performed by a competent individual equally qualified to the person removing or returning the equipment I
to service, and will be documented on the equipment outage check-list form DAP 3-5.
We feel that this added stringent requirement, in addition to the corporate and station management attention now being focused on equipment outages, provides adequate assurance that the likelihood of similar events recurring is acceptably small.
Mr. R. C. Knop of your staff granted a one-day extension, January 9, 1978, for this response by telecon on January 6, 1978.
Please direct any additional questions concerning these matters to this office.
Very truly yours, C.. A Cordell Reed Assistant Vice President Attachment
,,.n.
-a "dow n Canmonwealth Edison NRC Docket Nos. 50-10 50-237 Attachment 50-249 Infraction 1:
i l
Contrary to 10 CFR 50, Appendix B, Criterion V, and the licensee's Quality Assurance Program, maintenance work was per-formed on several Unit 2 control rod drives without tagging this i'-
equipment out of service as requested by the refuel foreman and as required in QP 3-52.
The failure to tag these control rod drive units out of service resulted in the ~ expulsion of blade guides from the reactor core.
The licensee did take the CRD hydraulic control system charging line out of service, however, j
this did not prevent inadvertant blade guide expulsion on the individual Ciu)':s left in the withdrawn position, when the hydraulic j
system was returned to service.
i Discussion:
I During a refueling outage with all fuel removed from the reactor, four control rod drives (CRD) were fully withdrawn and their blade guides removed without tagging this equipment out-of-l service.
The CRD hydraulic _ control system charging line was already l
out-of-service for maintenance work, but an additional equipment outage was not established for these individual drives.
Four blade guides were inadvertantly improperly seated when they were l
reinserted following completion of the LPRM work.
When a later scram signal was received, and after the CRD-hydraulic systsm had been returned to service, the blade guides were expelled from the reactor.
i Corrective Action and Corrective Action to Prevent Recurrence:
The four CRD's should have been individually taken out-of-service when their blade guides were removed to facilitate LPRM replacement.
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As mentioned in the cover letter to this Attachment, the corrective' actions which will be taken to ensure'that equipment is properly removed from service and the required functional tests are completed when it is returned to service must await the results of a special investigative task force.
The corrective action will, of course, be directed toward. ensuring that individual components are effectively and completely' removed from service for multiple outages when required.
Additionally, the Fuel Handling Department-has been instructed in the importance of following detailed refueling procedures.
Commonwealth Edison NRC Docket Nos. 50-10 50-237
' 50-249 Date of Full Comoliance:
The Station expects to be in full compliance when the corrective action recommended by the task force is implemented.
We expect implementation to be completed by March 31, 1978.
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Canmonwealth Edison NRC Docket Nos. 50-10 50-237 50-249 Infraction 2:
Contrary to reqcirements, LPCI valve 1501-3A was knproperly removed from service for maintenance.
As a result of the insufficient equipment outage, water discharging from the 2/3 diesel generator cooling water pump escaped through the valve and flooded the east LPCI room to a depth of approximately 3 feet.
This event was reported to you in Licensee Event Report 77-065/03L-0, Docket No. 50-237, dated December 22, 1977.
Discussion:
This event was similarly caused by personnel error in identifying and preparing equipment to be taken out-of-service.
The related maintenance procedure requires the 2/3 diesel generator cooling water pump to be taken out-of-service and a blind flange installed over the LPCI valve 1501-3A valve bonnet if repair work is extensive.
These steps were not accomplished as required.
As a result, while testing the 2/3 diesel generator for operability the cooling water pump discharge escaped through valve 1501-3A and flooded the east LPCI room to a depth of approximately 3 feet.
JCorrective Action and Corrective Action to Prevent Recurrence:
The corrective action to preve.nt recurrence must again 1
await the results and implementation of the recommendations of the special investigative task force.
Enmediate corrective action l
was to install a blind flange on the 1501-3A valve bonnet.
As
(
reported to you in the Licensee Event Report, this corrective l
action was completed within 50 minutes of the event.
The 2/3
' diesel generator cooling water pump was then run to inspect the l
flange and the 2/3 diesel generator operability test was repeated.
Supplemental corrective action included a thorough inspection of the LPCI/CS pump room, recalibration of the instrumentation in the room, and megcering of the affected pump motors.
The ECCS jockey pump motor was replaced and the LPCI and CS subsystems were demonstrated to be operable prior to Unit 2 startup.
Date of Full Compliance:
The Station expects to be in full compliance when the recommendations of the investigative task force are implemented.
This is expected to occur by March 31, 1978.
I i
Commonwaalth Edison NRC Dockst Nos. 50-10 50-237 50-249 f'
Infraction 3:
Contrary to Dresden Administrative Procedur.e DAP 3-5 the system valve lineup on the Unit 2A recirculation pump was not correctly-identified and explained on the equipment outage check-list resulting in the November 2, 1977 overpressurization of the 2A recirculation pump bowl and associated piping to 1435 psig.
Discussion:
As reported to you in Mr. Stephenson's letter to^
Mr. Keppler, dated November 10, 1977, at aporoximately 0510 hours0.0059 days <br />0.142 hours <br />8.43254e-4 weeks <br />1.94055e-4 months <br /> the "A" recirculation pump on Unit 2 was returned to' service following the replacement of the pump seal assembly.
At that time the seal purge system was returned to service while the recircu-lation loop remained isolated.
The reactor vessel head was removed at the time for the refueling outage.
The pump discharge, discharged bypass, and suction valves were left closed when the outage was cleared and the seal purge system was returned to operation.
As a result of improperly restoring this equipment to service, and additionally experiencing a failure of the seal purge system relief valve to lift as designed, at approximately 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> the pressure in the number one seal cavity of the recirculation pump was noted to be greater than 1200 psig as monitored in the control Room.
Subsequent investigation revealed the pressure to be 1435 psig in the pump discharge and suction piping.
An investigation of the event was made for a possible violation of Section 1.2 of the Technical Specifications.
The review indicated that no such-violation occurred as reported to you in the letter of November 10, 1977, because the pressurization I
event was similar to the initial hydrostatic test.
During con-struction on June 27, 1967, the primary system was pressurized to 1575 psig at approximately 1400F as required by ASME Boiler and Pressure Vessel Code, Section 3, Article 7, and USAS Power Piping Code, B31.1-1967, paragraph 137.41. (a).
Basically, it was concluded that the 2A recirculation loop was subjected to a pressure of' 140 psig less than the construction hydrostatic test.
As a result, i
there was no safety significance to the public or plant personnel.
I o
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Commonwealth Edison NRC Dockat Non. 50-10 50-237 50-249 Corrective Action and Corrective Action to Prevent Recurrence:
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The immediate corrective action was to isolate the seal purge system from the A recirculation pump.-
The seal purge system to B recirculation pmmp was isolated previously in the outage and the recirculation loop isolation valves for the B pump remained opened.
The relief valves designed to prevent this event have now been reset with proper setpoints.
The seal purge system relief valve lifting pressures will now be checked once each refueling cycle.
Additionally, applicable operating procedures are being revised to enstre the seal purge system is removed from service whenever the recirculation pumps are isolated.
Additional corrective action to prevent recurrence of improper equipment outages is awaiting implementation of the recommendations of the special investigative task force.
Date of Full Compliance:
Fu"1 compliance will be achieved when the recommendations of the special investigative task force are implemented.
This is expected to be completed by March 31, 1978.
/
4.
b Commonwealth Edison NRC Docket Nos. 50-10 50-237 50-249 Infraction 4:
Contrary to our Quality Assurance Program, procedure DMP 249 for hydrostatically testing the recirculation pump #1 seal is deficient in that specific valve line-ups upon completion of a hydrostatic test or valve line-ups to be made if the hydro-static test is not fully completed were not specified in the
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procedure.
The use of this deficient procedure resulted in inadvertently pressurizing the Unit 2A recirculation pump bowl and associated piping to 1550 psig on November 18, 1977.
Discussion:
This pressurization resulted from the fact that the hydrostatic test procedure DMP 249 did not require valve line-ups to be correctly returned following partial or full completion of the hydrostatic test.
When the hydrostatic test was started, but could not be completed, the correct valve line-ups were not made and the CRD system remained lined up to'the recirculation pump bowl.
Following the cancellation of the hydrostatic test, another job was in progress the next day utilizing the same CRD supply line for another purpose.
This resulted in the pressuri-zation of the recirculation pump bowl.
Corrective Action and Corrective Action to Prevent Recurrence:
Maintenance procedure DMP 249 appears deficient since no requirements are contained in the procedure to require a specific valve line-up to be implemented at the completion of the test or a cancellation of the test.
DMP 249 will be revised to include
' these valve line-up requirements.
Date of Full Comoliance:
The procedure will be reviewed and revised by March 1, 1978, and the station will be in full compliance at that time.
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