ML20150D363
| ML20150D363 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah, 05000000 |
| Issue date: | 03/16/1988 |
| From: | Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | |
| Shared Package | |
| ML20150D366 | List: |
| References | |
| FOIA-88-129, TASK-PII, TASK-SE SECY-88-082, SECY-88-82, NUDOCS 8803240114 | |
| Download: ML20150D363 (6) | |
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l POLICY ISSUE l
March 16, 1988 SECY-88-82 j
(Information) j For:
The Comissioners From:
Victor Stello, Jr.
Executive Director for Operations
Subject:
UPDATED STAFF ACTIONS FOR TENNESSEE VALLEY AUTHORITY SEQUOYAH UNIT 2 RESTART
Purpose:
To provide the status of the remaining issues required to be resolved prior to restart of Sequoyah Unit 2 and to request authorization for the staff to approve release of Sequoyah Unit 2 from its hold points to allow restart when the staff is satisfied that all open issues have been resolved.
Discussion:
The Tennessee Valley Authority (TVA) and the staff briefed the Commission on March 4, 1988.
At that time the staff provided the Comission the status of the remaining technical l
I issues that were required to be resolved prior to restart of Sequoyah Unit 2.
The. issues were the adequacy of electrical cables, the acceptability of the emergency diesel generators (EDGs), the allegations regarding 10 CFR Part 50, Appendix R, and the operational readiness of the plant.
These issues have been resolved, as discussed below, with the exception of the Appendix R
issue.
In response to the Staff Requirements Memorandum dated March 11, 1988, from S. Chilk to V.
Stello, on Sequoyah Restart, the staff has also provided a discussion of TVA's root cause analyses and corrective action programs, and allegations.
Silicone Rubber-Insulated Cables In SECY-88-11, dated January 13, 1988, the staff provided
~
the Comission the-status of issues requiring reso1ution before restart of Sequoyah Unit 2, including a discussion of the cable issues.
The staff indicated that the concerns regarding cable installation practices at Sequoyah had been resolved by the in-situ high-potential tests performed by TVA.
However, the testing identified a concern regarding silicone rubber-insulated cables.
After removal of the AIW silicone rubber-insulated
- cables, Sequoyah Unit 2
has approximately 600 silicone rubber-insulated single conductor cables remaining inside containment.
On November 24, 1987, resented the results of tests conducted at Wyle L bora ry which demonstrated that significantly lower y g ppt [ojj j 4catact:
Steven D. Richardson, OSP
insulation thicknesses would be sufficient for these cables to perform their intended safety functions in a harsh environment.
The staff reviewed the TVA test data and concluded that the remaining installed silicone rubber-insulated cables manufactured by Rockbestos and Anaconda are acceptable for service.
The staff noted, however, that the Wyle Laboratory test program demonstrated the qualified life of the silicone rubber-insulated cables for only 10 years.
Although the Wyle Laboratory test results demonstrated that a sufficient margin exists for startup, the staff has required TVA to qualify the silicone rubber-insulated cables for the 40 year life of the plant before coming out of the first refueling outage of Se.quoyah Unit 2 after restart.
Emergency Diesel Generators As
.a result of TVA employee concerns, allegations, and technical reports, potential deficiencies were identified with regard to the EDGs at Sequoyah Nuclear Plant.
These alleged deficiencies included over. loads, poor. niaintenance, inadequate calculations, inadequate preoperational testing and unacceptable voltage and frequency variations.
As a result of these allegations, TVA conducted a rereview and reanalysis of the Sequoyah EDGs.
This led TVA to implement plant modifications in the EDG load sequencing and timing.
In January 1988, TVA provided NRC staff with surveillance test results which raised ouestions with regard to whether, in view of the changes made in loads and load sequencing, sufficient margin existed on the EDGs to allow them to perform their safety function.
Based on an evaluation of the test data and a review of the TVA analysis by the staff and its consultants (Drs. Kusko and Peeran whose analysis is included as Enclosure 1),
the staff concluded the EDG margins that remain are sufficient to assure safe operatiun of Sequoyah.
TVA has committed to take corrective actions to provide additional assurance of adequate EDG performance.
These actions will be ccrrplete prior to returning Sequoyah Unit 1 to service following the first refueling outage following Unit I restart.
This schedule is acceptable to the staff.
During routine surveillance of the EDGs, the staff will continue to monitor the performance of these units.
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10 CFR Part 50, Appendix R Sequoyah Unit 2 is committed by Operating License Condition 2.C.13.c to four sections of 10 CFR Part 50, Appendix R.
These sections are III.G, III.J. III.L and III.O.
Based on these requirements, TVA prepared a safe shutdown logic j
analysis (SSLA).
Prior to the fall of 1987, the safe shutdown design basis for Sequoyah Unit 2 was Revision 6 to this analysis.
As a result of TVA's Calculation Verification Program, TV.i found this analysis to be deficient due to i
implicit unverified assumptions and requirements.
TVA performed a
recalculation of the SSLA and generated j
Revision 7.
Due to a lack of interface review within TVA, not all cognizant departments within the TVA organization had reviewed the revision.
Subsequent reviews by these TVA organizational entities resulted in the identification of additional concerns regarding the implementation of these requirements.
Mr. Bartlik, the alleger on Appendix R issues,.
participated in these reviews and raised several of his concerns to TVA.
TVA formed a review team to address the additional concerns that were raised and to determine which concerns required resolution prior to restart.
Concurrently, the NRC received allegations from Mr.
Bartlik regarding TVA's compliance with the requirements of Appendix R at Sequoyah.
Interviews were conducted with him.
This resulted in a staff request for additional information from TVA by letter dated February 26, 1988.
By letter dated February 27, 1988, TVA submitted Revision 8 to the Sequoyah Appendix R SSLA.
By letter dated March 2, 1988 TVA responded to the staff request for additional information.
Basea on a prelininary review of the TVA submittals by the staff and discussions conducted during a public meeting on March 9,
- 1988, the staff concluded that there was insufficient information to resolve all the allegations received.
Specifically, concerns remain in a number of areas:
spurious actuations of equipment due to cable-to-cable electrical faults as a result of a fire; provision of a reactor coolant system letdown path to comply with Appendix R requirements; and adequacy of TVA procedures for actions during a fire.
The staff is conducting an Appendix R inspection at Sequoyah to veri fy TVA program implementation and compliance with Appendix R in general and to review specific issues which were not resolved during the public meeting.
This inspection began on March 14, 1988 and is expected to be completed by March 18, 1985.
Preliminary results from the inspection team indicate that a
g
-4 some of the allegations have been substantiated and modifications will be required prior to restart.
Implementation of hardware and procedural changes are expected to be completed by March 21, 1988.
The NRC staff will review and inspect the changes before Sequoyah Unit 2 is permitted to enter mode 2.
Operational Readiness In SECY-88-11 the staff stated that TVA has made significant progress to support heatup and the staff will evaluate TVA's corrective actions through plant restart.
The staff has made a number of observations to date regarding -
the Sequoyah heatup and preparations for restart.
The heatup has progressed as expected considering the extended shutdown.
TVA has proceeded in a methodical and deliberate manner.
However, procedural and personnel errors have occurred.
For
- example, a
Preliminary Notification (PN-0SP-88-002) was recently prepared to provide the Comission with information on a problem found with status of the centrifugal charging pumps.
Some problems were identified with equipment status monitoring and shift comunications during this incident.
An enforcement conference has been scheduled at the site on March 17, 1988 and escalated enforcement action is under consideration for this event.
However, the staff does not believe this should delay authorization to restart.
In general, TVA's overall response to the errors has been conservative ano appropriate at both the operational staff and management levels.
In summary, although some problems have been found, the staff has observed significant improvement in Sequoyah's operational capability and considers the plant. and operational staff readiness acceptable for initiating mode 2 operations.
Root Cause Analyses and Corrective Action Program TVA ceveloped a revised progran for reporting Conditions Adverse to Quality (CAQ).
The improvements in this p cgram provide for documenting, evaluating, tracking, and correcting CAQs in a more effective.and timely manner.
A centralized tracking system has been developed to track adverse conditions to assure timely actions to resolve CAQs are taken.
Each significant adverse condition is required to be individually analyzed by line management to determine the root cause of the condition, the corrective action necessary to prevent recurrence, and the generic applicability to other TVA nuclear plants.
Trends are also evaluated to assist in
l 9
5 root cause evaluation and in determining action to preclude recurrence of adverse conditions.
Trend reports are issued to corporate and plant management to assist in identifying i
areas where increased management attention is needed.
The NRC staff has reviewed the program and monitored the implementation of the program during several inspections.
Based on these reviews, the staff has found the revised CAQ j
program and its implementation acceptable.
Most CAQs that 1
had been identified as Sequoyah restart items have been adequately closed out.
The remaining CAQs will be closed out prior to restart.
The staff will continue to monitor implementation of the program.
Aliegations l
Between 1985 and 1987,. Mr. Hicks provided written and oral statements to the NRC staff that were categorized into 61 separate allegations.
Of these, five do not pertain to Sequoyah.
The statements alleged general and specific deficiencies in many areas of TVA's nuclear operations.
The staff has completed the evaluation of most of the issues applicable to Sequoyah and found most to be substantiated.
The status of the allegations with regard to restart is as j
follows:
44 allegations are resolved and resolution has been documented 12 allegations are resolved but internal documentation is not complete Between 1984 and
- 1987, the NRC staff had received approximately 300 other allegations regarding TVA, of which 131 needed to be resolved prior to restart.
The status of these allegations is as follows:
96 allegations are resolved and resolution has been documented 33 allegations are resolved but internal documentation is not complete 2 allegations, related to Appendix R, will be resolved after TVA supplies additional information The staff continues to receive a number of late-filed allegations that are being addressed expeditiously in conformance with agency practice.
Those late-filed allegations with a
potential impact on safety will be resolved by the staff prior to restart.
1 t
i,
==
Conclusions:==
With the exception of the Appendix R issues all of the tech-nical issues requiring resolution prior to Sequoyah Unit 2 restart have been' resolved and all plant modifications which were required to be implemented prior to restart have been completed.
The Appendix R inspection will be completed by March 18, 1988 an implementation of hardware and procedural changes that have been identified as necessary to achieve compliance with Appendix R are expected to be completed by March 21, 1988.
The licensee is also expected to complete the remaining heatup evolutions by March 21 - 23, 1988.
The staff will inform the Commission when all items required for restart are complete.
The staff expects to be able to so inform the Comission by March 23; 1988.
. Recommenda tion:
(1)
That upcn receiving confirmation from the staff that the above described items are completed the Commission auth6rize the staff tc permit TVA to restart Sequoyah Unit 2.
The staff will orally provide to the Commission offices such confirmation en March 21, 1988.
A written. follow-up report will be provided.
(2)
The Comission authorize the staff to permit TVA to restart Sequoyah Unit 2 when the staff provides confirmation that all open issues have been resolved and mode 3 evolutions have been successfully completed.
A restart vote by the Commission should be possible by March 22, 1988.
1 V ctor SD T10, Jr Executive Director for Operations
Enclosure:
As stated DISTRIBUTION:
Commissioners OGC (H Street)