ML041610073
| ML041610073 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 06/08/2004 |
| From: | Michael Webb NRC/NRR/DLPM/LPD4 |
| To: | Sheppard J South Texas |
| Webb M, NRR/DLPM, 415-1347 | |
| Shared Package | |
| ML041680254 | List: |
| References | |
| TAC MC1046 | |
| Download: ML041610073 (13) | |
Text
June 8, 2004 Mr. James J. Sheppard President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483
SUBJECT:
SOUTH TEXAS PROJECT, UNIT 1 - ISSUANCE OF AMENDMENT RE: ONE-TIME EXTENSION TO STEAM GENERATOR INSERVICE INSPECTION FREQUENCY (TAC NO. MC1046)
Dear Mr. Sheppard:
The Commission has issued the enclosed Amendment No. 162 to Facility Operating License No. NPF-76 for the South Texas Project (STP), Unit 1. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated October 16, 2003, as supplemented by letter dated March 3, 2004.
The amendment provides a one-time change to TS 4.4.5.3a to extend the steam generator inspection interval to 44 months for STP, Unit 1 following refueling outage 1R10, which ended on October 24, 2001.
A copy of the related Safety Evaluation is enclosed. The Notice of Issuance will be included in the Commissions next biweekly Federal Register notice.
Sincerely,
/RA/
Michael Webb, Senior Project Manager, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-498
Enclosures:
- 1. Amendment No. 162 to NPF-76
- 2. Safety Evaluation cc w/encls: See next page
Mr. James J. Sheppard June 8, 2004 President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483
SUBJECT:
SOUTH TEXAS PROJECT, UNIT 1 - ISSUANCE OF AMENDMENT RE: ONE-TIME EXTENSION TO STEAM GENERATOR INSERVICE INSPECTION FREQUENCY (TAC NO. MC1046)
Dear Mr. Sheppard:
The Commission has issued the enclosed Amendment No. 162 to Facility Operating License No. NPF-76 for the South Texas Project (STP), Unit 1. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated October 16, 2003, as supplemented by letter dated March 3, 2004.
The amendment provides a one-time change to TS 4.4.5.3a to extend the steam generator inspection interval to 44 months for STP, Unit 1 following refueling outage 1R10, which ended on October 24, 2001.
A copy of the related Safety Evaluation is enclosed. The Notice of Issuance will be included in the Commissions next biweekly Federal Register notice.
Sincerely,
/RA/
Michael Webb, Senior Project Manager, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-498
Enclosures:
- 1. Amendment No. 162 to NPF-76
- 2. Safety Evaluation cc w/encls: See next page DISTRIBUTION:
PUBLIC RidsNrrDlpmDpr PDIV-1 r/f GHill (2)
RidsNrrDlpmLpdiv (HBerkow) RidsNrrDlpmLpdiv1 (RGramm)
RidsNrrPMMWebb RidsNrrLAMDBaxley TBoyce RidsAcrsAcnwMailCenter RidsOgcRp RidsRgn4MailCenter (BJohnson)
JTsao ACCESSION NO: ML041610073 *SE input dated 3/8/2004 OFFICE PDIV-1/PM PDIV-1/LA DE/EMCB/SC OGC PDIV-1/SC NAME MWebb DBaxley LLund* TSmith(NLO) RGramm DATE 5/27/04 5/27/04 3/8/2004 6/1/04 6/3/04 OFFICIAL RECORD COPY
STP NUCLEAR OPERATING COMPANY DOCKET NO. 50-498 SOUTH TEXAS PROJECT, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 162 License No. NPF-76
- 1. The Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment by STP Nuclear Operating Company* acting on behalf of itself and for Texas Genco, LP, the City Public Service Board of San Antonio (CPS), AEP Texas Central Company, and the City of Austin, Texas (COA) (the licensees), dated October 16, 2003, as supplemented by letter dated March 3, 2004, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, as amended, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D. The issuance of this license amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.
- STP Nuclear Operating Company is authorized to act for Texas Genco, LP, the City Public Service Board of San Antonio, AEP Texas Central Company, and the City of Austin, Texas, and has exclusive responsibility and control over the physical construction, operation, and maintenance of the facility.
- 2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and Paragraph 2.C.(2) of Facility Operating License No. NPF-76 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 162, and the Environmental Protection Plan contained in Appendix B, are hereby incorporated in the license. The STP Nuclear Operating Company shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3. The license amendment is effective as of its date of issuance and shall be implemented within 30 days from the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Robert A. Gramm, Chief, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance: June 8, 2004
ATTACHMENT TO LICENSE AMENDMENT NO. 162 FACILITY OPERATING LICENSE NO. NPF-76 DOCKET NO. 50-498 Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains marginal lines indicating the areas of change.
REMOVE INSERT 3/4 4-14 3/4 4-14
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 162 TO FACILITY OPERATING LICENSE NO. NPF-76 STP NUCLEAR OPERATING COMPANY, ET AL.
SOUTH TEXAS PROJECT, UNIT 1 DOCKET NO. 50-498
1.0 INTRODUCTION
By application dated October 16, 2003 (ADAMS Accession No. ML032930285), as supplemented by letter dated March 4, 2004 (ADAMS Accession No. ML040700529), STP Nuclear Operating Company (the licensee or STPNOC), requested changes to the Technical Specifications (TSs) for South Texas Project (STP), Unit 1. The supplement dated March 4, 2004, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the NRC staffs original proposed no significant hazards consideration determination as published in the Federal Register on November 12, 2003, (68 FR 64139).
The proposed changes would revise the TSs to provide a one-time change to TS 4.4.5.3a to extend the steam generator inspection (SG) interval to 44 months for Unit 1, following refueling outage 1R10, which ended on October 24, 2001.
2.0 REGULATORY EVALUATION
STP, Unit 1 began commercial operation on August 25, 1988. Therefore, the General Design Criteria (GDC) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50 Appendix A and the Standard Review Plan (NUREG-0800) are applicable to STP, Unit 1.
GDC-14, "Reactor Coolant Pressure Boundary," and GDC-31, "Fracture Prevention of Reactor Coolant pressure Boundary," require that the reactor coolant pressure boundary have an extremely low probability of abnormal leakage, of rapidly propagating failure, and of gross rupture.
Furthermore, GDC-32, "Inspection of Reactor Coolant Pressure Boundary," requires that components that are part of the reactor coolant pressure boundary be designed to permit periodic inspection and testing of critical areas to assess their structural and leaktight integrity.
The general requirements for the inservice inspection program for SG tubes, which constitute part of the reactor coolant pressure boundary, is based on the plant TSs.
Section 4.4.5.3a of the STP, Unit 1 TS states, in part, that The first inservice inspection following steam generator replacement shall be performed after 6 Effective Full Power Months but within 24 calendar months of initial criticality after the steam generator replacement.
Subsequent inservice inspections shall be performed at intervals of not less than 12 nor more than 24 calendar months after the previous inspection. If two consecutive inspections, not including the preservice inspection, result in all inspection results falling into the C-1 category or if two consecutive inspections demonstrate that previously observed degradation has not continued and no additional degradation has occurred, the inspection interval may be extended to a maximum of once per 40 months... The C-1 category inspection result is defined in TS 4.4.5.2.c as less than 5 percent of the total tubes inspected are degraded and none of the inspected tubes are defective. A degraded tube is defined in TS 4.4.5.4.a.4 as a tube containing imperfections greater than or equal to 20 percent of the nominal wall thickness caused by degradation. A defective tube is defined in TS 4.4.5.4.a.6 as an imperfection of such severity that it exceeds the plugging limit (i.e., 40 percent of the nominal wall thickness).
3.0 TECHNICAL EVALUATION
In May 2000, STPNOC replaced the original SGs in STP, Unit 1 during the 1RE09 refueling outage. The replacement SGs are Westinghouse Delta 94 model which include improvements in the materials and designs to minimize corrosion such as the use of thermally treated alloy 690 tubing, broached-hole tube support configuration, hydraulic tube expansion joints in the tubesheet, and stainless steel anti-vibration bars.
In October 2001, STPNOC performed the first inservice inspection of the STP, Unit 1 replacement SGs during the 1RE10 refueling outage which ended on October 24, 2001.
During Cycle 11 operation, on July 31, 2002, the NRC approved STPNOCs amendment request for a one-time 40-month inspection interval immediately following the 1R10 refueling outage for the STP, Unit 1 SGs as discussed in NRCs Amendment No. 140 (ML022040265).
On March 27, 2003, STP, Unit 1 commenced the 1R11 refueling outage. The SGs were not inspected during the 1RE11 refueling outage. However, STPNOC performed a foreign object search and retrieval (FOSAR) of the feedwater distribution piping in steam generator 1D. For reasons unrelated to the SGs, the 1RE11 refueling outage was extended. During the extended 1RE11 outage, the SGs remained in cold shutdown and wet lay-up condition. The 1RE11 outage ended on August 8, 2003. The following day, August 9, 2003, STP, Unit 1 commenced Cycle 12, which is scheduled to be completed in early March 2005.
There are about 41 calendar months from the inspection of the replacement SGs during the 1RE10 refueling outage in October 2001 to the end of Cycle 12 in March 2005. Since the one-time 40-month inspection interval in current TS 4.4.5.3 would not be satisfied by a projected 41-month interval, STPNOC requested a one-time 44-month inspection interval.
In the NRC's safety evaluation for Amendment No. 140, the NRC staff reviewed the scope and results of the inspection performed during the 1R10 refueling outage, improved design features in the replacement SGs, and related industry operating experience. The NRC staff's evaluation of these issues remains applicable to the proposed 44-month inspection interval amendment request, but will not be repeated within this evaluation. For the proposed one-time 44-month inspection interval amendment request, the NRC staff focused its evaluation on the condition of
the replacement SGs during the extended shutdown in 2003 and on the structural and leakage integrity of the SG tubes in a 44-month inspection interval.
In its letter dated October 16, 2003, STPNOC stated that during the shutdown period, the STP, Unit 1 SGs were in a cold shutdown and wet lay-up condition with chemistry being maintained in accordance with the secondary chemistry guidelines as discussed in Electric Power Research Institute (EPRI) Topical Report (TR), TR-102134-R5, "PWR [Pressurized Water Reactor]
Secondary Water Chemistry Guidelines." (Due to a typographical error, the TR number for this document was incorrect in the letter dated October 16, 2003.) Table 5-1 of EPRI TR-102134-R5 provides specific values for parameters in the SG bulk solution such as pH level, hydrazine, sodium, chloride, sulfate, boron (if boric acid was used), and dissolved oxygen.
In the NRC staffs request for additional information, the NRC staff asked STPNOC to discuss whether the values of these parameters were followed for the wet lay-up of the STP, Unit 1 SGs.
In its response dated March 3, 2004, STPNOC stated that parameter values for all SGs remained in specification for the duration of the wet lay-up except for hydrazine and pH readings in SG 1D, which were related to the FOSAR inspection as discussed above. Once the FOSAR activity was completed, STPNOC refilled SG 1D and corrected the out of specification condition in a timely manner in accordance with EPRI TR-102134-R5.
STPNOC also stated that procedures at STP, Unit 1 follow EPRI report, TR-102134-R5, to require that the SG bulk solution be mixed and sampled three times per week (after parameters are in the normal range) until the parameters are stable, then mixed, and sampled weekly. This sampling schedule was interrupted by maintenance work on the feedwater isolation valves in 1RE11, which removed SG lay-up chemistry sampling capability from March 29, 2003, until April 15, 2003. When sampling capability was returned, lay-up chemistry parameters were still in specification. The sampling scheduled was then followed for the duration of the wet lay-up.
STPNOC stated that in accordance with EPRI report, TR-102134-R5, a positive nitrogen overpressure was maintained during filling, draining, and cold shutdown to minimize oxygen ingress into the STP, Unit 1 SGs, except during the FOSAR in SG 1D as described above.
Once the FOSAR inspection was completed, a positive nitrogen overpressure was established.
The NRC staff finds that STPNOC has followed the EPRI TR-102134-R5 guidance on wet lay-up of the STP, Unit 1 SGs. Where there were exceptions because of the FOSAR inspection or maintenance work, STPNOC took timely corrective actions to maintain water chemistry within the EPRI guidelines.
With regard to the structural and leakage integrity of the SG tubes, STPNOC stated in its letter dated October 16, 2003, that "The Operational Assessment performed at 1RE10 found that the operational requirements for continued SG operation over the next three cycles (Cycles 11, 12, and 13) are met without exceeding the structural integrity recommendations of draft Reg Guide 1.121." In its request for additional information, the NRC staff asked STPNOC to discuss whether the operational assessment results would cover the 44-calendar month inspection interval. In its response to the NRC staffs question, STPNOC stated that three 18-month cycles were evaluated for a total of 54 calendar months in its operational assessment.
The NRC staff asked STPNOC to show the accuracy of its operating assessment and to discuss how the tube degradation is modeled and projected so as to obtain adequate and/or
conservative results. In its response, STPNOC stated that no degraded tube condition of any amount of wall loss was experienced during the 1RE10 inspection. This inspection result is consistent with industry experience regarding SG tubes made of Alloy 690 material. The 1R10 inspection result was based on a bobbin examination of 100 percent of the tubes plus selected supplemental rotating probe inspections consistent with the STP, Unit 1 TSs and industry guidelines.
In its request for additional information, the NRC staff asked STPNOC to clarify whether it has performed an assessment on the leakage integrity of the SG tubes. In its response to the NRC staff question, STPNOC stated that it has performed an assessment on the leakage integrity of the SG tubes. Nuclear Energy Institute (NEI) document NEI 97-06, "Steam Generator Program Guidelines," specifies that an operational assessment be performed to assess if observed degraded mechanisms will continue to meet tube structural and leakage integrity requirements until the next inspection. No degradation mechanisms were observed in any SG, so projections of operational leakage or accident leakage were not applicable. STPNOC stated that it uses a defense-in-depth design with power-compensated N-16 monitors on each SG providing control room readout capability of leak rates. This design feature provides assurance that in the unlikely event of operational leakage, it would be detected, trended, and monitored for appropriate action.
STPNOC stated further that the only indication from the 1RE10 inspection that required a tube integrity analysis was one potential loose part signal. Results from a bounding loose part analysis for the potential foreign object near tube R43C79 in SG 1D showed that the object would not adversely affect the structural or leak integrity of that SG for at least three operating cycles (54 calendar months). Although no wear was observed in the vicinity of the potential loose part, a bounding analysis assumed that such a loose part existed at the highest flow location (to excite the loose part) and further assumed that the most limiting calculated tube cyclic deflections observed anywhere in the bundle were coincident with the high flow and part location. STPNOC calculated tube wear ranges based on various orientations of the loose part to cause future wear assuming undetected 20 percent initial tube wall wear had occurred. The results were compared to a minimum wall thickness of 15 mils. STPNOCs analysis showed that both leakage integrity and structural integrity would be maintained for the next three operating cycles for a total of 54 calendar months.
During the 1RE11 shutdown, a cable stabilizer from a feedwater heater plugged tube became dislodged and was caught in the main feedwater regulating valve of SG 1D. STPNOC retrieved small wire pieces from this stainless steel wire rope stabilizer during the FOSAR of the main feedwater header and from the flow distribution ring header and sludge collector within SG 1D.
The NRC staff notes that the size of a loose part passing through the feedwater distribution ring is limited by the 0.29 inch flow holes. STPNOC assessed the potential of unrecovered wire by evaluating the aforementioned bounding loose part analysis performed during the 1RE10 refueling outage against the characteristics of the potential unrecovered wire rope from this incidence. The existing analysis was found to be bounding for the potential of small wire fragments from this event.
Based on the fact that STP, Unit 1 has not experienced any tube wear from initial operation of the replacement SGs through 1RE10, combined with the analysis of loose part wear, STPNOC stated that it is confident that the STP, Unit 1 SGs will satisfy the performance criteria on
structural integrity, accident-induced leakage, and operational leakage at the end of the 44-month inspection interval.
On the basis of information submitted, the NRC staff finds that STPNOC has demonstrated that the structural and leakage integrity of the SG tubes would be maintained during the 44-month inspection interval immediately following the 1R10 refueling outage. The NRC staff further finds that STPNOCs proposed change to TS 4.4.5.3a in the STP, Unit 1 TSs is acceptable because STPNOC has demonstrated that the structural and leakage integrity of the SG tubes will be maintained during the 44-month inspection interval immediately following the 1R10 refueling outage that ended on October 24, 2001. The NRC staff concludes that STPNOC may incorporate the proposed changes to the STP, Unit 1 TSs.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Texas State official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (68 FR 64139 dated November 12, 2003). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: J. Tsao Date: June 8, 2004
South Texas Project, Units 1 & 2 cc:
Senior Resident Inspector A. H. Gutterman, Esq.
U.S. Nuclear Regulatory Commission Morgan, Lewis & Bockius P. O. Box 910 1111 Pennsylvania Avenue, NW Bay City, TX 77414 Washington, DC 20004 A. Ramirez/C. M. Canady Mr. T. J. Jordan, Vice President City of Austin Engineering & Technical Services Electric Utility Department STP Nuclear Operating Company 721 Barton Springs Road P. O. Box 289 Austin, TX 78704 Wadsworth, TX 77483 Mr. L. K. Blaylock S. M. Head, Manager, Licensing Mr. W. C. Gunst Nuclear Quality & Licensing Department City Public Service Board STP Nuclear Operating Company P. O. Box 1771 P. O. Box 289, Mail Code: N5014 San Antonio, TX 78296 Wadsworth, TX 77483 Mr. C. A. Johnson/A. C. Bakken Environmental and Natural Resources AEP Texas Central Company Policy Director P. O. Box 289 P. O. Box 12428 Mail Code: N5022 Austin, TX 78711-3189 Wadsworth, TX 77483 Jon C. Wood INPO Matthews & Branscomb Records Center 112 East Pecan, Suite 1100 700 Galleria Parkway San Antonio, TX 78205 Atlanta, GA 30339-3064 Arthur C. Tate, Director Regional Administrator, Region IV Division of Compliance & Inspection U.S. Nuclear Regulatory Commission Bureau of Radiation Control 611 Ryan Plaza Drive, Suite 400 Texas Department of Health Arlington, TX 76011 1100 West 49th Street Austin, TX 78756 D. G. Tees/R. L. Balcom Texas Genco, LP Brian Almon P. O. Box 1700 Public Utility Commission Houston, TX 77251 William B. Travis Building P. O. Box 13326 Judge, Matagorda County 1701 North Congress Avenue Matagorda County Courthouse Austin, TX 78701-3326 1700 Seventh Street Bay City, TX 77414 May 2003
South Texas Project, Units 1 & 2 Susan M. Jablonski Office of Permitting, Remediation and Registration Texas Commission on Environmental Quality MC-122 P.O. Box 13087 Austin, TX 78711-3087 Mr. Terry Parks, Chief Inspector Texas Department of Licensing and Regulation Boiler Division P. O. Box 12157 Austin, TX 78711 Mr. Ted Enos 4200 South Hulen Suite 630 Ft. Worth, Texas 76109