ML19340A576
| ML19340A576 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 10/27/1977 |
| From: | Bolger R COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML19340A575 | List: |
| References | |
| NUDOCS 8008280635 | |
| Download: ML19340A576 (6) | |
Text
.
~. C:mmonwarlth Edison
~
One Fast Nat,onat Plata Ch*Caqo Illinois
" Acdress Reply to Post Othee Box 767 Chicago.. Ul.nois 60690 October 27, 1977 Mr. James G. Keppler, Director Directorate of Inspection and Enforcement - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
Dresden Station Unit 1, 2, and 3 Response to IE Inspection Report Nos. 50-10/77-27, 50-237/77-24, and 50-249/77-24 NRC Docket Nos. 50-10/237/249 Reference (a) :
J. G. Keppler letter to B.
Lee, Jr.,
dated October 5, 1977.
Dear Mr. Keppler:
Attached to this letter'is Commonwealth Edison's response to the three items of noncompliance identified in Appendix A of Reference (a).
With respect to the items mentioned in the letter of transmittal, we have agreed to review the reliability of the diesel generators and to initiate any corrective action that is identified.
We have also increased the visual surveillance on the diesel genera-tor cooling water pump breakers from once per shift to twice per shift.
As a result of further instrument drift problems with the circuits which count the number of operable LPRM's per APRM channel, we have decided to adjust the setpoint of the circuits to a more conservative value than is actually required.
Any instrument drift bett een surveillances should then not result in exceeding a Technical Specification.
We will continue to conduct the surveillance of these circuits on a weekly basis through November.
At that time, a review will be made to determine the effectiveness of our corrective action and, if acceptable, the surveillance frequency will be reduced to its original monthly basis.
These actions were described in Reportable Occurrence Report No. 77-041/OIT-0 for Dresden Unit 3, Docket'No. 50-249.
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CCi l: 0 W
e Commonwealth Edison Mr. J. G. Keppler October 27, 1977 With respect to the concerns regarding the rc;urring problems with the Dresden Unit 2 HPCI valve, Reportable Occurrence Report No. 50-237/77-35 dated 09-23-77 described the cc erective action which we plan to implement.
The problems with t.is valve have revealed a need to replace the apparently oversized rator operators on several fast-closing, safety-related valves with smaller motors.
The motors which are presently installed subject the valve stems to a higher than d2 sired torque and this appears to have contributed to these events.
A design deficiency in the valve control circuitry of these fast-closing valves has alse been iden-tified previously, causing the valve to cycle excessively during surveillance testing.
During the current refueling outage the HPCI talve 2-2301-8 torque switch and valve stem will be replaced.
Two separ-ate modifications, M12-2-76-76 and M12-2-76-85, designr 2 to elimin-ate cycling will be installed during the outage.
If the smaller motors ordered for Modification 12-2-76-78 arrive before the end of the cutage, the 2-2301-8 valve motor will be replaced -ith a smaller one.
The accumulated water in the switch boxes and motor appraently came from stem packing leaks from the 2-220-2.nd 2-220-90 valves.
The 2-220-2 valve was repacked and the 2-220-90 alves will be repacked during the outage.
Problems from leaking 2-2 0-90 valves will be eliminated in a longer term program by replacing them with packless valves.
This should eliminate the predominant source of water in the switch boxes and on the motor windings.
Please direct any additional questions concerning these matters to this office.
Very truly yours, ho k.b.
R. L.
Bolger Assistant Vice' President Attachments I
50-010 Commonwealth Edison NRC Docket Nos. 50-237 50-249 Attachment Infraction:
Contrary to Technical Specifications, Section 3.7.C.1, the secondary containment requirements for Units 2 and 3 were not followed on September 14, 1977.
The inspectors found both Units 2 and 3 secondary containment personnel access doors inoperable with no interlock or alarm functioning on the doors.
Discussion & Corrective Action:
Upon discovering Units 2 and 3 secondary containment personnel access doors inoperable, work requests were written to investigate and restore proper operation.
Unit 2 access doors were checked and it was discovered that the reactor building door's limit switch was out of adjustment.
This switch was replaced and the interlock returned to service.
Unit 3 interlock was inoperable because the panic bar was out of adjustment and this prevented the lock from resetting properly.
The panic bar was tightened and the interlock returned to service.
Our interim measures to assure the proper functioning of these doors continue to require that if the interlock doors are found inoperable, a work request is written to make repairs and a guard placed at the interlock to assure secondary containment is maintained.
This guard remains at the interlock until repairs are completed and the interlock returned to service.
Corrective Action to Avoid Further Noncompliance & Date of Full Compliance:
The long term corrective action for the problems experi-enced on the interlock doors has been to obtain new doors and a new interlock system.
This action has been delayed due to problems in obtaining a vendor that would provide properly designed doors.
The present schedule ^for this modification is to begin work on the Unit 3 interlock doors during the week of November 7; the Unit 2 and 2/3 Diesel Generator room interlock door work will start the week of November 28.
m 50-010 Commonw2alth Edissn NRC Docket Nos. 50-237 50-249 Attachment Infraction:
Contrary to 10 CFR 50, Appendix B, Criterion V, and the licensee's Quality Assurance Manual, OPS-51, no acceptance criteria is used to evaluate the timing test of the Unit 1 power operated containment isolation valves.
These valves are tested quarterly, and for the year 1976, the time recorded for various valves to close, varied considerably.
Discussion:
As pointed out in the inspection report, the containment isolation valves for Dresden Unit 1 are timed quarterly and the results reviewed by the Operating Engineer in accordance with station procedures.
We agree that this review should be enhanced by explicitly referencing the acceptance criteria in the sur-veillance procedure.
More than half of these valver are also included within the ASME Inservice Inspection Program and those valves are time, and evaluated, in accordance with the ASME Boiler and Pressure Vessel Code,Section XI.
Since the current program was initiated in March, 1977, the evaluation of the timing of those valves in the ISI Program has been conducted by Technical Staff Personnel in accordance with the criteria specified in Section XI.
Corrective Action to Avoid Further Noncompliance & Date of Full Compliance:
Timing criteria for the operation of the containment iso-lation valve 3 will be established and explicitly specified within procedure DOS 1600-1.
This action will be completed by January 1, 1978 and we will be in full compliance at that time.
,/
50-010 Commonwealth Edison NRC Docket Nos. 50-237 50-249 Infraction:
Contrary to Unit 1 Technical Specifications, Section 4.9.A.5, and contrary to Unit 3 Technical Specifications, Section 4.5.A, surveillance was not accomplished within the required fre-quency for both units.
On Unit 1, measurement of each cell voltage, specific gravity of each cell, and temperature of every fifth cell was not completed for a period of almost 5 months, between October 28, 1976 and March 9, 1977.
On Unit 3, the LPCI and Core Spray, pump and valve operability surveillance was not completed within the specified technical specification frequency requirements..
_ Discussion:
Even though instances of untimely or incomplete performance of routine surveillances are occurring less frequently with continued management attention, we do still experience occasional surveillance discrepancies.
We have discovered some confusion with our compu-
+erized surveillance schedule and our Licensee Event Reports have
- c. ascribed the changes we have made to the computer model.
We have identified a need for more frequent updates of the schedules, with 3 0nger lead times provided for advanced awareness of upcoming sur-
' rillances, and a need to unambiguously indicate the latest possible ampletion date while still complying with the two separate surveil-lance interval extensions permitted by the Technical Specifications.
We feel that the reprogramming of the computer model which was com-pleted last month will greatly assist in eliminating missed surveil-lances as revised data is entered into the computer file.
We have also recognized that our monthly management audit 2
of our surveillance program only identifies missed surveillances.
As described in our Licensee Event Report #50-249/1977-32, beginning August 1, 1977, an Engineering Assistant in the Operating Department has been assigned to provide an additional check of the surveillance program by recording completed surveillances on comprehensive charts and by closely monitoring those charts to anticipate upcoming sur-veillances.
We fully expect that this Engineering Assistant will provide the required anticipatory review of the program.
We further agree that there is a need in some cases to improve the review of completed surveillance checklists.
The Super-intendent has initiated an analysis by the Assistant Superintendent and the Lead Operating Engineer of our procedures for thoroughly reviewing completed surveillances.
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Finally, our investigations have not confirmed that an inadequate surveillance may have contributed to the failure of the diesel fire pump to automatically start.
Surveillance DOS-4100 to check the diesel fire pump battery is performed weekly.
After the May 17, 1977, surveillance identified ten cells with low speci-fic gravities, the battery was charged.
Earlier surveillances in May did not reveal any degradation of the battery.
only one cell gravity reading fell slightly below the surveillance acceptance criteria thereafter until the failure of the pump to start on July 29, 1977, ultimately led to replacement of the battery.
No trend in gravity readings was readily apparent during the three month period and, in particular, all cell specific gravity readings the weeks before and after adding water on June 21, 1977, were acceptable.
We feel that no additional corrective action is war-ranted for this event.
Corrective Action Taken, Corrective Action to Avoid Further Noncompliance, and Date of Full Compliance Beginning August 1, 1977, an Engineering Assistant in the Operations Department has been assigned to record completed surveillances on comprehensive charts and to anticipate the need to schedule upcoming surveillances.
Also, in September, 1977, our computerized surveillance schedule was reprogrammed to unambiguously indicate the latest possible completion dates for upcoming surveil-lances.
These changes should eliminate any confusion about the surveillance schedule and provide improved coordination for the program.
The Superintendent has reqyested that the Assistant Super-intendent and the Lead Operating Engineer analyze the adequacy of the review process of completed surveillance checklists and-present any recommended bnprovements for consideration by January 1,1978.
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