ML20209F422
| ML20209F422 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 08/18/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8609120149 | |
| Download: ML20209F422 (11) | |
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L44 860818 804 5N 157B Lookout Place AU6181986 Director of Nuclear Reactor Regulation Attention:
Mr. B. Youngblood, Project Director PWR Project Directorate No. 4 Division of Pressurized Water Reactors (PWR)
Licensingf[
U.S. Nuclear Regulatory' Commission Washington,D.C.20S5f
Dear Mr. Youngblood:
In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 Your January 15, 1986 1ctter to S. A. White requested additional information regarding five design control questions at the sequoyah Nuclear Plant (SQN).
Enclosed is our response to those questions.
In addition, your letter also requested information regarding the Office of Nuclear Power (ONP) Quality Assurance organization.
As you are aware, details on the organization of the Division of Nuclear Quality Assurance are provided in our revised Corporate Performance Plan which was submitted on March 10, 1986 and amended on July 17, 1986 and in TVA's Quality Assurance Topical Report (TVA-TR75-1A).
If you have any questions conccrning these issues, please get in touch with M. J. Burzynski at (615) 870-7275.
Very truly yours, TENNESPEE VALLEY AUTHORITY R. Gridley, Director Nucicar Safety and Licensing Enclosure
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l,i 0609120149 860018 PDR ADOCK 03000327 G
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~2-Director of Nuclear Reactor Regulation kkN)}8$86 Enclosure cc (Enclosure):
U.S. Nuclear Regulatory Commission Region II Attn:
Dr. J. Nelson Grace Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. James Taylor, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Carl Stahic Sequoyah Project Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20814 HRHiMJB:TSAISCP cc (Enclosure):
RIMS, MR AN 12A-C H. L. Aboreromble. ONP. O&P0-4. Sequoyah T. S. Andreychek. ONP, O&PS-4, Sequoyah M. J. Buraynskl. ONP, 06PS-4, Sequoyah R. W. Cantroll, BR IN 76B-C M. R. Harding. ONP 06P8-4. De$1uoyah T. A. Ippolito. LP SN 121B-C K. M. Jenison, Sequoyah - NRC R. B. Kelly, LP AN 45A-C J. A. Raulaton, W10 C126 C-K H. S. Sanger. Eli B33 C-K R. K. Seiberling, 116C EB-C 0637c
ENCLOSURE queption 1 An explanation of why the design control problems identified at Browns Ferry Nuclear plant (BFN) and identified via tho employee concerns at Watts Bar Nuclear plant (WBN) do not apply at Sequoyah Nuclear plant (SQN).
Responne TVA has in the past and continues to evaluate design control problems found through the employee concern program and programmatic reviews at individual facilities both across its entire program and on a case-by-case basis.
For example, based on the recent results from assessments, inspections, and evaluations TVA has concluded that the primary cause of our design control problems is related to weaknesses in our program for control of design modifications during plant operations.
In order to address these problems and their root causes, TVA has inillated reorganizations and responsibility realignments. These actions are doscribed from a corporate view in volume one of the revised TVA Nuclear performance plan (NPp).
Additional actions required to correct these problems include the development of effective procedures for control of plant modifications and an expanded engineering scope for conducting all design-related 10 CFR 50.59 evaluations at our oporating plants.
Implementation of these actions at SQN will be performed in two phases.
The first phase will include the establishment of preliminary procedures and the organizational changes mentioned above. Also, before SQN restart TVA will perform a verification of those systems or portions of systems required to mitigate FSAR Chapter 15 design basis accidents and achieve subsequent safe shutdown. This effort is directed at providing confidence that plant modifications implemented since issuance of the operating license can be supported by engineering analysis and documentation.
The second phase will be devoted to establishing a long-term solution including the development of final procedures and a revised modification control procons for all of TVA's operating plants.
In summary, TVA has been able to identify and correct weaknesses in the design control process that have surfaced through various assessments, inspections, and evaluations.
We believe that we are taking appropriate corrective actions to address these matters.
Question 2 An explanation as to how all of the many issues from employee concerns, NSRS concerns, QA audits, etc., will be reviewed, and how the scope of the reviews will bound the issues.
Responce The following paragraphs describe the sources of concerns and issues and how they are being evaluated and resolved.
I.
Overall_TVA_Pror. rams A.
Employee Concerns Employee concerns arising from the following sources are being evaluated and resolved through the Watts Bar Employee Concerns Task Croup (ECTC) for all TVA nuclear sites:
- Employee concerns received under the Watts Bar Employee Concerns Special Program
- Employee concerns identified to the TVA Nuclear Safety Review Staff (NSRS)
- Employee concerns from the TVA Employee Concern Program which were identified before February 1,1986 (the old ECP)
Employee concerns expressed under TVA's Office of Nuclear Power Employee Concern Program which became effective February 1, 1906 and any new allegations received from NRC are being addressed and resolved on an individual basis.
S. A. White's May 2, 1986 letter to Victor Stello and R. L. Gridley's May 7, 1986 letter to H. R. Dentoa describe the ECTC and TVA Office of Nuclear Power Employee Concern Program.
Furthermore, these programs were discussed in detail with NRC on April 17 and May 12, 1986.
In the caso of Quality Assurance (QA) audit findings, responses within the Office of Nuclear Power are reviewed by Division of Nuclear Quality Assurance for acceptability. A procedure exists for escalation of findings to ensure resolution of the finding is achieved.
B.
Other Issuns -
The ECTG is also responsible for evaluating and resolving the following:
- Issues arising from the " Systematic Analysis of Concerne/Isnues at
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TVA" performed by Stone & Webster of externally generated correspondence (e.g., NHC, INPO, and Consultant documentation) f or the 16-month period before January 1986.
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- Issues from the NSRS which did not result from expressed employee concerns and remain open at this time.
II. SON-Soecific A.
Employee Concerns Before February 1,1986 - Restart Related Employee Concerns that will be evaluated for impact on SQN restart are:
1.
Those concerns which specifically name SQN.
2.
Those concerns initially determined by the ECTG to be potentially generically applicable to SQN as well.
3.
Those concerns that, during the evaluation process at WBN, are determined to be potentially generically applicable to SQN as well.
The evaluation will include the following:
1.
Assignment of concerns to subcategories and elements.
2.
Identification of issues within each element.
3.
Identification of restart issues in accordance with the restart criteria.
4.
Review of the results of previous evaluations by other than the ECTG as related to the elements to determine if each issue is sufficiently addressed.
5.
Whore previous evaluations have not been conducted or where existing documentation does not sufficiently address all rectart issues, evaluation methodology will be developed and implemented.
6.
Based upon the evaluation and findings, concluulons will be made.
The reports will contain sufficient information and references to f aellitate an independent review and assessment.
The SQN Site Director will review the reports and prepare corrective action plans for findings contained in the reports.
The ECTO will review and provide concurrence with the planned corrective actions.
The Site Director will determine those correctivo actions that must be implemented before rectart.
This determination la to be mado using the " Criteria for Determination of Restart Items" provided in Volume 2 of the Nuclear performance Plan.
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-4 B.
Employee Concerns Before February 1, 1986 - Not Restart Related Employee concerns which are not restart related will be evaluated and resolved by the ECTG in conjunction with concetms which apply to other TVA locations. These have been consolidated into technical areas and are being investigated on that basis because of the similarity among many of the concerns expressed on other sites.
Corrective actions are being developed to address the issues representing these similar or related concerns.
C.
Other Issues 1.
NSRS and " Systematic Analysis issues and concerns are now being.
evaluated by the ECTG and will be evaluated and resolved Individually or collectively as appropelate to the issues and concerns taking into account the program for restart of Sequoyah.
3 Additionally, the corrective actions necessary for restart are' being defined and tracked in SQN's startup schedule which is reviewed weekly by site management.
2.
QA audit findings are evaluated by SQN line management using TVA and site procedures and processes established for this purpose which fix the timeframe for site evaluation and response and provide in the case of QA findings for escalation of issues to upper TVA management.
D.
Additional Information TVA project managers have also been established to evaluato issues related to many issues such as welding, environmental qualification, and electrical issues. These evaluations encompass many of the issues arising from employee concerns NSRS concerns, etc., and will be the source of resolutions for findinFs of the ECTG, where appropriate.
For SQN, NSRS concerns, employee concerns, and QA-identified restart issues, in the areas of weldir.g. environmental qualification, cables, and electrical calculations have been and are being transmitted to the resrective project managers for these areas to provido an extra measure of assurance that the scope of reviews conducted and any proposed corrective actions adequately address the various issues.
Applicable QA-identified restart issues and NSRS concerns have also been or are being transmitted to responsible TVA managers to ovaluate and address in the areas of design control, configuration control, j
cable tray and conduit hangers, and pipe hangers and anchor bolts.
-5 In addition, a SQN restart task force has been established. One of the responsibilities of this task force has been to determine those items which must be completed before startup.
A criteria has been established, and a composite startup list is being developed based on a review of (for example) significant condillon reports, operational experience review items, maintenance items, open licensing issues, commitments, Nuclear Safety Review Board recommendations, newly identified technical issues, as well as employee concerns, NSRS concerns, and QA findings.
The actions necessary for restart are being defined and tracked in SQN's startup cchedule which ic reviewed weekly by site management.
E.
Summary The process described above will ensure that safety-significant. issues arising out of employee concerns, QA findings, NSRS concerns, etc.,
will bound identified problem areas and be adequately addressed for the restart of SQN.
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Question 3 A more complete description of the basis for your conclusion that SQN design controls were adequate prior to June 1985.
Response
In order to address the adequacy of SON design controls before June 1985, TVA contracted with Gilbert-Commonwealth (G/C) for a second design control review. The purpose of this review was to provide TVA management with the additional assurance that the modifications to SQN were adequate and consistent with safety and licensing commitments. The scope of the G/C review involved the main and auxiliary feedwater systems and the modifications made on those systems since the issuance of the operating license for SQN unit.l.
The plan for this G/C review was submitted to NRC in a letter to B. J. Youngblood from J. A. Domer dated January 24, 1986.
This review, NRC's inspection (IE Report Nos. 50-327 -328/86-27), as well as reviews by INPO, have been completed and weaknesses identified. TVA has developed a corrective action program as outlined in the response to question No. 1.
This program will ensure that the design control weaknesses identified are corrected. The program will also verify that those systems or portions of systems required to mitigate FSAR Chapter 15 design basis accidents and achieve subsequent shutdown can perfoam their safety functions.
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Question 4 provide an explanation of how design changes initiated at WBN to correct a potential safety problem would be addressed with respect to SQN, assuming the plant design feature in question is identical to both plants.
Response
Any identified " potential safety problem" requiring corrective design action is considered by TVA to be a condition adverse to quality (CAQ).
procedures have been in place for a number of years governing the identification, documentation, evaluation, and resolution of CAQs. The program requires that corrective action for CAQs be determined and documented on quality assurance records and, for significant CAQs, the cause of the condition be determined and corrective actions taken to preclude repetition of the CAQ. This action includes a determination of the condition's potential applicability to other issues associated with the plant in question or to other plants.
Subsequent affirmation findings in this area would be documented by separate CAQs for each plant.
CAQs initiated on WBN are reviewed for potential generic applicability to other TVA plants.
If it is determined that the condition applies to SQN, corrective action (through the initiation of SQN-specific CAQs) is initiated and implemented.
In addition, where CAQs are known or suspected of being applicable to more than one plant at the time of identification, identical plant-specific and/or generic Nonconformance Reports (NCRs) or significant condition reports (SCRs) have been issued.
Where revisions to approved TVA desigr output documents are deemed necessary, Engineering Change Notices (ECNs) are issued.
procedures governing the handling of ECNs have required since 1978 the initiation of an NCR (indicating the existance of a CAQ) for ECNs issued to correct design errors. This procedural requirement was further clarified to require the processing of an NCR when an issued design document required revision to correct a condition that "could have resulted in a required safety-related function not being fulfilled." The current program has similar provisions for the identification of CAQs as part of the ECN process.
In the area of handling employee concerns, it should be noted that employee 3
concerns forwarded for dispositioning are assessed for needed corrective actions. Where these corrective actions involve design changes, ECNs are prepared.
In these instances, the procedural requirements for identifying CAQs during the ECN process as described in the preceding paragraph apply.
In addition to the procedural aspects of the issue as described above, it should be noted that during the construction phase for SQN and before commercial operation for SQN unit 2, the design change (ECN) process for both SQN and WBN was managed by one design project organization. Design changes initiated for either plant were considered for the other plant as a matter of Consequently, further assurance is provided (through the course.
organizational structure utilized in this timeframe) that design changes initiated for WBN were adequately considered for SQN.
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. Question 5 A description of the electrical design calculations review program currently in progress for the Sequoyah facility. This should include description of how
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this program is being incorporated in the overall design review effort.
Response
As discussed in our February 27, 1986, submittal, electrical calculations required to support the electrical design had not been completely defined for TVA's nuclear plants. The basic design approach over past years has been-to do whatever calculations were necessary to develop detailed designs and to support the design bases. This resulted in calculations being generated based on the design engineer's best judgment of what was required.
Some calculations were not officially documented and controlled, and those that were of ficially documentud were not kept up to date for future design changes. These facts were identified by INp0 in its review of both the Bollefonte Nuclear plant (BLN) and WBN, in the BLN Electrical Evaluation performed within TVA's Division of Nuclear Engineering (DNE) and in a DNE quality assurance audit deviation.
TVA has performed a formal review effort tu entobiluh the minimum set of electrical calculations required to support the electrical design for BLN.
In response, TVA has developed an index of required calculations for SQN, based on the BLN effort and information obtained from other A/Es and utilities.
The plant electrical systems are:
auxiliary power system control power system lustrumentation und control systems communications systems lighting systems main generator / step-up transformer system raceway systems station grounding systems In evaluating the requiremente for SQM restart. TVA has performed an examination of existing calculations to determine which of the required calculations have been performed and whether or not they are current.
Included in this evaluation was a determination of which calculations must be performed or revised before restart to provide assurance that safety-related equipment can perform properly for design conditions.
Assurance may be gained not only from calculations but from test results, inference, satisfactory operation to date, or combinations thereof.
This evaluation concluded that coicuidtionu muut be performed before restart for the auxiliary and control power systems, instrumentation and control systems, and raceway systems. TVA is proceeding to scope and schedule the work associated with completion of this task.
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Justifications are also required for those calculations contained within the minimum set that have not been determined to be required for restart.
Controls and procedures will also be developed for performing, indexing, and maintaining the required calculations for all future activities and design changes.
For the long term, with respect to the overall design review effort, TVA plans to develop software programs and an electrical data base with an overall objective to establish consistency between nuclear projects in the performance of calculations, to ensure that all future work is incorporated into the design change process, and to be more responsive and timely in the performance of electrical calculations.
To preclude recurrence of this problem, retraining will also be conducted.
TVA has also contracted with Sargent and Lundy Engineers to perform an independent assessment of the electrical calculation program for each nuclear plant. The scope of this work basically includes a review of the minimum set of required calculation, a review of those deemed by TVA to be required before startup of the respective plant, a review of the justification for not performing certain calculations before startup, the rationale and methodology for identifying these calculations, a review of existing procedures and FSAR requirements, and a sample review of eclected electrical calculation documents.
An Electrical Inouen Mana5er han been cutabiluhed within TVA effective November 25, 1985, to ensure that this problem area is adequately managed.
This manager will be responsible for ensuring that the management of all activities associated with the technical objectives listed below are carried out, that all work performed will establish that the electrical systems now in place at TVA's nuclear plants will perform their intended safety functions, and that programs and procedures are in place for future activities.
The electrical issues program objectives are:
1.
That all coluulations required to support the electrical systems design basis for each nuclear plant are well defined.
t 2.
The adequoey of existing electrical calculations.
Where neceunury take action to enuure existing electrical a.
calculations are adequate.
b.
Where necennary tuhe action to have electrical calculations made that l
do not exist.
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That prodromo und procedurou are in pinte for all future activities.
l TVA is generically inveutigatin6 the other disulpline areas (civil, mechanical, and nuclear) to ensure the adequacy of design calculations in
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these discipline areas. Assessments of all calculations are being made including sampling to obtain the necessary verification.
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