ML091550571
| ML091550571 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 06/01/2009 |
| From: | Wen P C Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| Wen P | |
| References | |
| Download: ML091550571 (11) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, DC 20555 - 0001 June 1, 2009 MEMORANDUM TO: ACRS MEMBERS FROM: Peter Wen, Senior Staff Engineer
/RA/ Reactor Safety Branch - A Advisory Committee on Reactor Safeguards
SUBJECT:
CERTIFICATION OF THE MINUTES OF THE PLANT LICENSE RENEWAL SUBCOMMITTEE MEETING REGARDING SUSQUEHANNA STEAM ELECTRIC STATION UNITS 1 AND 2 ON APRIL 1, 2009 The minutes of the subject meeting were certified on May 27, 2009, as the official record of the proceedings of that meeting. A copy of the certified minutes is attached.
Attachment:
As stated
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, DC 20555 - 0001 May 27, 2009 MEMORANDUM TO: William Shack, Chairman Plant License Renewal Subcommittee FROM: Peter Wen, Senior Staff Engineer, Reactor Safety Branch - A ACRS
SUBJECT:
THE MINUTES OF THE MEETING OF THE SUBCOMMITTEE ON PLANT LICENSE RENEWAL REGARDING SUSQUEHANNA STEAM ELECTRIC STATION UNITS 1 AND 2 ON APRIL 1, 2009, IN ROCKVILLE, MARYLAND A working copy of the minutes for the subject meeting is attached for your review. Please review and comment on them at your earliest convenience. If you are satisfied with these minutes please sign, date, and return the attached certification letter.
Attachments: Certification Letter Minutes cc w Attachments: Susquehanna License Renewal Subcommittee Members cc w/o Attachments: E. Hackett C. Santos S. Duraiswamy
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, DC 20555 - 0001 May 27, 2009 MEMORANDUM TO: Peter Wen, Senior Staff Engineer Reactor Safety Branch - A ACRS FROM: William Shack, Chairman Plant License Renewal Subcommittee
SUBJECT:
THE MINUTES OF THE MEETING OF THE SUBCOMMITTEE ON PLANT LICENSE RENEWAL REGARDING SUSQUEHANNA STEAM ELECTRIC STATION UNITS 1 AND 2 ON APRIL 1, 2009, IN ROCKVILLE, MARYLAND I hereby certify, to the best of my knowledge and belief, that the minutes of the subject meeting on April 1, 2009, are an accurate record of the proceedings for that meeting. ______________________May 27,2009
____ W. Shack Date Plant License Renewal Subcommittee Chairman Certified By: W. Shack Issued: June 1, 2009 Certified on May 27, 2009 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS MINUTES OF THE MEETING OF THE SUBCOMMITTEE ON PLANT LICENSE RENEWAL REGARDING SUSQUEHANNA STEAM ELECTRIC STATION UNITS 1 AND 2 ON APRIL 1, 2009 INTRODUCTION On April 1, 2009, the ACRS Subcommittee on Plant License Renewal held a meeting regarding Susquehanna Steam Electric Station (SSES) Units 1 and 2, in Room T-2B3, 11545 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss the SSES application for license renewal and NRC staff review of it. In addition to the NRC staff, representatives from PPL Susquehanna, LLC (PPL) (the SSES operator and the licensee) made presentations to the Committee. The meeting was convened at 8:30
a.m. and adjourned at 11:56 a.m.
ATTENDEES ACRS Members William Shack, Subcommittee Chairman John Stetkar, Member Otto Maynard, Member Mario Bonaca, Member Sam Armijo, Member John Sieber, Member Charles Brown, Member Harold Ray, Member Said Abdel-Khalik, Member John Barton, Consultant Peter Wen, DFO Principal NRC Speakers Brian Holian, NRR Evelyn Gettys, NRR Glenn Meyer, Region I PPL Presenters Rick Pagodin John Krais Nick D'Angelo Dave Flyte Other Attendees NRC Staff PPL OTHER S. Lee D. Pelton P.Brady M. Miller L. Lund J. Dozier D. Filchner K. Putuan B. Elliot R. Conte R. Gardner P. Lindberg D. Ashley J. Medoff M. Hager M. Wadley B. Harris Z. Xi M. Mcfarland C. Frickter J. Robinson A. Hiser D. Roth G. Sosson D. Nguyen G. Newman G. Stevens A. Fakhan J. Davis B. Lehman B. Swoyer K. Knaog O. Yee B. Rogers M. Tafazzoli E. Eilolz A. Paulsen D. Alley J. Weik J. Ruether G. Thomas R. Vaucheq J. Williams
R. Mathew J. Daily S.Min R. Li C. Yang E. Smith W. Golumbfski H. Ashar J. Daily R. Sun R. Auluck A. Wong K. Miller S. Sheng W. Smith A. Prinaris R. Mathew N. Iqbal J. Huang C. Doutt E. Wong M. Yoder D. Hoang E. Patel The presentation slides and handouts used during the meeting are attached to the office copy of these minutes. The presentations to the Subcommittee are summarized below.
OPENING REMARKS BY CHAIRMAN SHACK Chairman Shack convened the meeting by introducing the ACRS members present. Chairman Shack stated that the purpose of the meeting was to review the Susquehanna license renewal application, the draft safety evaluation report and associated documents. He stated that the Subcommittee would hear presentations from representatives of the Office of Nuclear Reactor Regulation (NRR), and the applicant, PPL. He said that the Subcommittee would gather information, analyze relevant issues and facts, and formulate proposed position and action, as appropriate, for deliberation by the Full Committee. The rules for participation in the meeting were announced as part of the notice of the meeting previously published in the Federal Register. Chairman Shack acknowledged that the Committee had received no written statements or requests for time to make oral statements from members of the public.
DISCUSSION OF AGENDA ITEMS Staff Introduction Mr. Brian Holian, Director of Division of License Renewal in NRR, introduced the principal staff members present. He said that the staff has incorporated the recommendations from the Office of Inspector General's license renewal audit report, by increasing the peer review effort on the draft SER. He highlighted three issues that were not included in the staff's draft SER, but are currently being reviewed by the staff. These issues include: (1) metal fatigue cycle counting, (2) dissolved oxygen content used in the metal fatigue calculation, and (3) Boral issue. He then called upon the applicant's presenter, John Krais, to begin the applicant's presentation.
Applicant Presentation Mr. John Krais, Manager of Special Projects for PPL Susquehanna, introduced the PPL team present at the meeting to support their presentation to ACRS. Mr. Krais then started his presentation by describing the general information related to plant location, design, current plant status, operating history, major improvements made to the plant over the years, license renewal team, and license renewal schedule. He stated that PPL submitted the extended power uprate (EPU) application to NRC at approximately the same time (October, 2006) as it submitted its license renewal application (LRA). He stated that the NRC has approved SSES Units 1 and 2 EPU request to increase the maximum power level to 3,952 MWt. He also stated that the evaluations documented in the LRA were performed at the extended power conditions.
Mr. Dave Flyte, PPL License Renewal Lead Engineer, described the SSES license renewal project, scoping, application of NRC's Generic Aging Lessons Learned (GALL) report, commitment process, and time limited aging analyses (TLAA). He pointed out that the SSES LRA was prepared by following NEI 95-10 guidance and GALL report.
For aging management reviews (AMRs), he stated that 82% of AMR line items were consistent with GALL report. For aging management programs (AMPs), 19 out of the 51 AMPs are new programs that require to be developed before the period of extended operation. He stated that PPL made 59 commitments in support of license renewal, and they have been entered into SSES Commitment Tracking Process with station personnel assigned to ensure for implementation.
NRC Staff Presentation Ms. Evelyn Gettys, the NRR Project Manager for Susquehanna License Renewal, provided an overview of the staff's license renewal review. She reported that the staff found the applicant's scoping and screening methodology is consistent with the requirements of 10 CFR 54.4 and 54.21(a)(1). In addition, she reported that the applicant has adequately identified those structures, systems, and components (SSCs) within the scope of license renewal, as required by 10 CFR 54.4(a), and those systems and components subject to an AMR, as required by 10 CFR 54.21(a)(1).
Mr. Glenn Meyer, Team Leader of the Region I inspection team, provided a summary of Region I inspections regarding the license renewal scope and screening, and implementation of AMPs. He stated that the objective of the scoping and screening inspection was to confirm that the applicant included all appropriate SSCs in the scope of license renewal as required by the rule. The inspection team focused on the nonsafety-related SSCs that could affect safety-related equipment. He concluded that these SSCs were implemented as required by the rule, 10 CFR 54.4(a)(2).
For the AMP inspection, Mr. Meyer reported that the inspection team reviewed 29 AMPs, including 12 new AMPs and 17 existing AMPs, and performed detailed inspections on the conditions of HPCI system on both units. Mr. Meyer also said that the inspection
team identified some license renewal items that required the applicant to take corrective actions either through a LRA amendment, a LRA commitment, or resolution of onsite procedure changes. He stated that the applicant's license renewal activities were conducted well as described in the LRA and the on-site procedures. He stated that the inspection results support a conclusion of reasonable assurance that aging effects will be adequately managed and intended functions will be maintained.
Ms. Gettys also presented the staff's review results of LRA Section 3, Aging Management Review Results, and Section 4, Time-Limited Aging Analyses (TLAA). For LRA Section 3, she indicated that the staff determined that the aging effects, with the exception of the Boral issue, will be adequately managed for the period of extended operation as required by 10 CFR 54.21(a)(3). However, for LRA Section 4, she indicated that the staff has additional questions on the following two issues: (1) cycle counting used in the metal fatigue monitoring and (2) dissolved oxygen content used in the environmental fatigue usage factor calculations.
SER Open Items Ms. Gettys stated that the staff's draft safety evaluation report (SER) with Open Items was issued on March 2009. Although the SER did not specifically listed any open item in the document provided to the ACRS, the staff is currently asking the applicant to provide additional information for the following areas:
AMR Section 3.3.2.2.6 Boral Issue This issue stemmed from the industry operating experience that inspection of Boral test coupons at some plants revealed bulging and blistering of the aluminum cladding. Mr. Brian Holian, Director, Division of License Renewal, NRR, in his opening statement, informed the Committee that the staff, as a result of recent license renewal reviews with several other plants, has identified this issue as an emerging issue. Ms. Gettys stated that the NRR staff is in the process of requesting additional information regarding aging management of Boral panels used in the spent fuel pool racks.
Cycle Counting The applicant uses its Fatigue Monitoring Program to monitor and track the numbers and severity of critical thermal and pressure transients for the selected reactor coolant system components. Ms. Gettys provided the Committee with information regarding the staff's draft RAI on the fatigue monitoring program (see staff's slide 31). She stated that the staff is in the process of asking the applicant questions regarding the transient monitoring and cycle counting, which were used in the fatigue evaluations. In response to Member Stetkar's question, Dr.
Sam Li of the NRR staff replied that the applicant did previously provide the staff with cycle counting information, but only for the past 10 years. The staff needs information for the cycle counting going back to the original operation to confirm the applicant's projected cycle numbers.
Dissolved Oxygen Content The dissolved oxygen level is one of the variables used in the environmental cumulative usage factor calculations. The applicant used the normal water chemistry operation in early plant operations, but switched to hydrogen water chemistry operation on both units after 1999. Ms. Gettys stated that the applicant previously provided the dissolved oxygen data, covering the period from 1994 through 2007, but didn't provide the data for period before 1994. She stated that the staff is in the process of asking PPL to provide the missing data.
Chairman Shack asked about the water chemistry sampling locations and oxygen bounding values used in the environmental cumulative usage factor calculations. Mr. Rick Pagodin of PPL staff indicated that PPL will provide a complete response during the full committee meeting.
COMMENTS AND OBSERVATIONS FROM THE SUBCOMMITTEE MEMBERS Station Blackout Recovery Scoping Mr. Philip Brady of PPL staff described the topic of station blackout (SBO) recovery scoping. He stated that the SSES license renewal scoping includes the transmission conductors from startup transformers T10 and T20 to circuit breakers in the switchyard as well as the circuit breakers themselves. He believes that this license renewal SBO recovery boundary is in accordance with the latest NRC guidance (draft LR-ISG-2008-01). Ms. Gettys of the NRR staff reported that as a result of the staff's review, the applicant has included sections of the offsite switchyard in the scope of license renewal for SBO in accordance
with 10 CFR 54.4(a)(3).
Underground Medium Voltage Cables Mr. Dave Flyte of PPL staff described SSES underground medium voltage cables. He stated that the 15 kV cables are non-safety related circuit and are within the scope of license renewal for the SBO recovery. The circuit consists of two segments: (1) from the low side of the startup transformers to the turbine building which contains five manholes and (2) from the reactor building to the engineered safeguard services transformer which is a short run with no manhole.
He also stated that SSES has observed submerged cables in two of these manholes in the segment 1 cable circuit. He stated that SSES has committed to an aging management program to inspect these manholes, and to drain them, if necessary, on a periodic basis to keep these cables from exposure to standing water. Member Stetkar asked whether PPL has performed any testing on the insulation of these cables. Mr. Brady replied that SSES has performed the double testing (i.e., a power factor testing) on these cables on a four-year frequency under a prevent maintenance program. This testing is checking at the actual insulation to confirm that the conductor insulation is not degrading.
Condition of Containment Member Bonaca asked questions regarding the suppression pool containment liner status. Mr. Bruce Swoyer of PPL staff replied that the applicant has inspected the containment liners on both units. In 2007, NDE-qualifiers divers performed visual inspection on the liners and found no unacceptable conditions.
During the meeting, neither the applicant nor the NRC staff specifically discussed the material condition of containment. Members Bonaca, Brown, and Sieber expressed interest in hearing more about this topic during the next full committee meeting. Mr. Holian of the NRR staff rep lied that this topic will be discussed in detail during the full committee meeting.
Condition of Core Shroud Chairman Shack asked questions regarding the condition of core shroud. Mr. Bruce Swoyer of PPL staff replied that the applicant has inspected the core shrouds in both units, in accordance with BWRVIP inspection guidance and found that most of the horizontal welds in both units exhibited some degree of cracking. The most extensive crack is located at mid H4 weld in Unit 1 and has an average crack depth of 0.6 inches and is approximately 60 percent around the circumstance. He stated that crack growth rate and fracture toughness for all identified flaws have been evaluated. The evaluation results concluded that these flaw indications as acceptable for further service without the need for repair or replacement at this time. SSES plans to inspect the same welds in Unit 1 in 2010, based on the results of these inspections and evaluations.
Mr. John Barton of ACRS asked whether the applicant applied any modifications to the shroud. Mr. Bruce Swoyer replied that SSES has not modified the shroud and it is as originally installed.
In response to Mr. Barton's question regarding inspection of core shroud welds that are inaccessible (e.g., welds H8 and H9), Mr. Swoyer replied that SSES performed UT inspection on these welds from outside the vessel in accordance with the BWRVIP guidance.
In response to Member Armijo's questions regarding the application of hydrogen water chemistry operation and its impact on the reactor internals, Mr. Swoyer replied that PPL plans to increase the amount of hydrogen to account for the power increase as a result of implementation of EPU. He also reported that so far, other than the core shroud area, PPL has not found any new cracks in any reactor internals components.
Impact of EPU on LRA The NRC authorized an EPU to increase the maximum power level for SSES Units 1 and 2 from 3,489 MWt to 3,952 MWt on January 2008. Member Bonaca asked how applicant's license renewal aging management programs and commitments will reflect operation at a higher power level. Mr. John Krais of PPL staff replied that PPL's aging management programs and evaluations
documented in the LRA were performed at the EPU conditions. Both EPU and
LRA projects were prepared by the same group.
Mr. Dave Flyte added that the applicant has committed to perform an operation experience review at EPU conditions to identify any impacts on aging management programs for systems, structures, and components, before entering the period of extended operation. (Commitment 52).
FatiguePro Benchmark The applicant uses FatiguePro software for stress-based fatigue monitoring of the feedwater nozzle and control rod drive (CRD) penetrations. FatiguePro is also used to calculate the fatigue cumulative usage factor (CUF) at other limiting plant locations in the plant. Chairman Shack asked the applicant to explain the benchmark that has been performed for the FatiguePro software. Mr. Gary Stevens (PPL consultant) replied that SSES was one of the first plants to implement FatiguePro and has 20 years of experience using this software. He reported that originally, FatiguePro was developed for stress-based fatigue calculations of the feedwater nozzle and CRD penetrations. The benchmark was performed to compare (1) the stress intensity predictions against the results from the design basis of ASME NB-3200 code and (2) the fatigue usage factors against the results from the stress reports for these two components. He further explained that the application of FatiguePro at Susquehanna did not take credit of a finite element analysis that yielded lower stress results.
Mosture Separator Vane Member Abdel-Khalik asked a question regarding the root cause of the damage of turbine moisture separator vane. Mr. Krais replied that the cause of the.damage was a result of shifting direction of vanes after a long period of operation. He further explained that the nature of the damage was due to erosion and degradation of spacers between the vanes themselves.
Member Sieber asked about the upgrade replacement vanes that were installed. Mr. Krais replied that the primary upgrade was implemented in the design of vanes; the upgrade included the use of double-pockets design instead of single-pocket vanes.
Main Steam Flow Restrictor Inspection Program Ms. Gettys of NRR staff reported that the applicant has withdrawn the Main Steam Flow Restrictor Inspection Program (the staff's presentation slide# 22). Member Abdel-Khalik asked what is the concern with the inspection of the main steam flow restrictor. Mr. Erach Patel (the staff's consultant) replied that the aging effects related to this component are loss of material, cracking, and reduction of fracture toughness due to the thermal embrittlement. He explained that PPL managed the aging effects of loss of material and cracking through its ISI program. He also stated that in accordance with the GALL Report, XI.M12, recommendations, the aging effect of reduction fracture toughness due to the thermal embrittlement need not to be considered. This is because the main steam flow restrictors in SSES are made of centrifugally cast material. For these reasons, the staff agreed with the applicant's assessment that the Main Steam Flow Restrictor Inspection Program is not needed.
Member Abdel-Khalik asked how the flow restrictor inspection is performed, how is the loss of material indicated, and how the change in flow diameter is detected. Mr. Dave Pelton of the NRR staff stated that the staff and the applicant will return to the Committee with a complete response.
Other In SSES, the condensate storage tank (CST) and the refueling water storage tank (RWST) rest on oil-sand pads. Member Sieber and Mr. Barton asked about the material and the inspection of these tanks. Mr. Mitch McFarland of PPL staff replied that these tanks are made of carbon steel, and SSES will perform one-time inspections, using a UT technique on the tank bottoms, to check against the design thickness and any indication of loss of material, prior to entering into the period of extended operation.
There are several welds in the BWR reactor vessel internals that are inaccessible and cannot currently be inspected using conventional visual or ultrasonic techniques. The BWR utilities are relying on the BWRVIP programs to address this issue. Member Bonaca asked about the progress and when this issue will be resolved. Mr. Bruce Swoyer replied that BWRVIP is working hard to resolve this issue. Recently, they were succeeding in resolving the issue of inspecting inaccessible locations in the spray piping welds inside the vessel.
As a result of NRC's authorization for an EPU for SSES Units 1 and 2, the applicant has instrumented the Unit 1 steam dryer to monitor and evaluate structural adequacy of the new steam dryer design. Member Abdel-Khalik asked about the data collected from the steam dryer instrumentation. Mr. Krais reported that the assumption made in the licensing for EPU was conservative compared with the actual data collected from the measurement.
SUBCOMMITTEE DECISIONS AND ACTIONS Following the staff and applicant presentations and discussions, Chairman Shack asked members if they had additional issues and concerns that needed to be discussed.
Members were asked for their overall observations from the presentations. Other than those issues described above, no additional issues were identified. He then adjourned the meeting by thanking everyone for attending the meeting.
BACKGROUND MATERIALS PROVIDED TO THE SUBCOMMITTEE
- 1. PPL LLP License Renewal Application for SSES, Units 1 and 2, dated September 13, 2006. 2. Draft Draft NRC Safety Evaluation Report with Open Items, dated March 2009. 3 NRC Staff Audit Summary Report, dated January 16, 2009. 4. NRC Inspection Report 05000387/2008007 and 05000388/2008007, dated February 27, 2009.
NOTE: Additional details of this meeting can be obtained from a transcript of this meeting available in the NRC Public Document R oom, One White Flint North, 11555 Rockville Pike, Rockville, MD, (301) 415-7000, downloading or view on the Internet at http://www.nrc.gov/reading-rm/doc-collections/acrs/ can be purchased from Neal R. Gross and Co., 1323 Rhode Island Avenue, NW, Washington, D.C. 20005, (202) 234-
4433 (voice), (202) 387-7330 (fax), nrgross@nealgross.com (e-mail).