ML12286A078: Difference between revisions
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| number = ML12286A078 | | number = ML12286A078 | ||
| issue date = 10/31/2012 | | issue date = 10/31/2012 | ||
| title = | | title = Issuance of Amendments to Revise the Technical Specifications 3/4.8.1 in Support of Unit Station Service Transformer Modifications | ||
| author name = Lingam S | | author name = Lingam S | ||
| author affiliation = NRC/NRR/DORL/LPLII-2 | | author affiliation = NRC/NRR/DORL/LPLII-2 | ||
| addressee name = Shea J | | addressee name = Shea J | ||
| addressee affiliation = Tennessee Valley Authority | | addressee affiliation = Tennessee Valley Authority | ||
| docket = 05000327, 05000328 | | docket = 05000327, 05000328 | ||
Line 13: | Line 13: | ||
| document type = Letter, License-Application for Facility Operating License (Amend/Renewal) DKT 50, Safety Evaluation | | document type = Letter, License-Application for Facility Operating License (Amend/Renewal) DKT 50, Safety Evaluation | ||
| page count = 25 | | page count = 25 | ||
| project = TAC:ME8772, TAC:ME8773 | |||
| stage = Approval | |||
}} | }} | ||
=Text= | |||
{{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 October 31,2012 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 | |||
==SUBJECT:== | |||
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 -ISSUANCE OF AMENDMENTS TO REVISE THE TECHNICAL SPECIFICATIONS 3/4.8.1 IN SUPPORT OF UNIT STATION SERVICE TRANSFORMER MODIFICATION (TS- SQN-12-01) | |||
(TAC NOS. ME8772 AND ME8773) | |||
==Dear Mr. Shea:== | |||
The Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment No. 332 to Facility Operating License No. DPR-77 and Amendment No. 325 to Facility Operating License No. DPR-79 for the Sequoyah Nuclear Plant, Units 1 and 2, respectively. These amendments are in response to your application dated May 23, 2012, as supplemented by letter dated August 23, 2012. The amendments request changes to Technical Specification 3/4.8.1 to include a surveillance requirement to demonstrate the required offsite circuits OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 KiloVolt Unit Board from the normal supply to the alternate supply. This change is necessary as a result of the planned modifications to the plant design and operating configuration that would install generator circuit breakers and new unit station service transformers to allow their use as an offsite power supply. | |||
A copy of the Safety Evaluation is also enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice. | |||
Sincerely, | |||
~<f'~ | |||
Siva P. Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 | |||
==Enclosures:== | |||
: 1. Amendment No. 332 to DPR*77 | |||
: 2. Amendment No. 325 to DPR-79 | |||
: 3. Safety Evaluation cc w/enclosures: Distribution via Listserv | |||
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-327 SEQUOYAH NUCLEAR PLANT, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 332 License No. DPR-77 | |||
: 1. The Nuclear Regulatory Commission (the Commission) has found that: | |||
A. The application for amendment by Tennessee Valley Authority (the licensee) dated May 23,2012, as supplemented by letter dated August 23,2012, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) I and the Commission's rules and regulations set forth in Title 10 of the Gode of Federal Regulations, Chapter I; B. The facility will operate in conformity with the application, 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 Commission's regulations; D. The issuance of this 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 Commission's regulations and all applicable requirements have been satisfied. | |||
-2 | |||
: 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. DPR-77 is hereby amended to read as follows: | |||
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 332, I are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications. | |||
: 3. This license amendment is effective as of its date of issuance, to be implemented prior to startup from Unit 2 fall 2012 refueling outage. | |||
FOR THE NUCLEAR REGULATORY COMMISSION | |||
~44'~~ | |||
le~. QUichocho, Acting Chief lant licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation | |||
==Attachment:== | |||
Changes to the Facility Operating License and Technical Specifications Date of Issuance: October 31,2012 | |||
ATTACHMENT TO LICENSE AMENDMENT NO. 332 FACILITY OPERATING LICENSE NO. DPR-77 DOCKET NO. 50-327 Replace Page 3 of Operating License DPR-77 with the attached page 3. | |||
Replace the following pages of the Appendix A Technical Specifications with the attached pages. | |||
The revised pages are identified by amendment number and contain marginal lines indicating the areas of change. | |||
REMOVE INSERT 3/48-1 3/48-1 3/4 8-2 3/4 8-2 | |||
(4) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required. any byproduct, source or special nuclear material without restriction to chemical or physical form, for sample analysis. instrument calibration or associated with radioactive apparatus or components; and (5) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate. | |||
such byproduct and special nuclear materials as may be produced by the operation of the Sequoyah and Watts Bar Unit 1 Nuclear Plants. | |||
C. This license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth In 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules. regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions speCified or incorporated below: | |||
(1) Maximum POwer Level The Tennessee Valley Authority is authorized to operate the facility at reactor core power levels not in excess of 3455 megawatts th~rmal. | |||
(2) Technical Specifications The Technical SpAr:ifications contained in Appendices A and S, as revised through Amendment No. 332 are hereby Incorporated into this license. The licensee shall operate the facility in accordance with the Technical Specifications. | |||
(3) Initiar Test Program The Tennessee Valley Authority shall conduct the post-fuel-Ioading initial test program (set forth in Section 14 of Tennessee Vaney Authority's Final Safety Analysis Report. | |||
as amended). without making any major modifications of this program unless modifications have been identified and have received prior NRC approval. Major modifications are defined as: | |||
: a. Elimination of any test identified in Section 14 of TVA's Final Safety AnalySis Report as amended as being essential; | |||
: b. Modification of test objectives, methods or acceptance criteria for any test identified in Section 14 of TVA's Final Safety Analysis Report as amended as being essential; | |||
: c. Performance of any test at power level different from there described; and Facility Operating License No. DPR-77 Amendment No. 332 | |||
3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES OPERA"rlNG LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE: | |||
: a. Two physically independent circuits between the offsite transmission network and the onsite Class 1E distributIon system@, and | |||
: b. Four separate and independent diesel generator sets each with: | |||
: 1. Two diesels driving a common generator | |||
: 2. Two engine-mounted fuel tanks containing a minimum volume of 250 gallons of fuel, per tank | |||
: 3. A separate fuel storage system containing a minimum volume of 62,000 gallons of fuel, | |||
: 4. A separate fuel transfer pump, and | |||
: 5. A separate 125-voH D.C. distribution panel, 125-volt D.C. | |||
battery bank and associated charger, APPLICABILITY: MODES 1, 2, 3 and 4. | |||
ACTION: | |||
: a. With one offsite A.C. circuit of the above required A.C. electrical power source inoperable, demonstrate the OPERABILIlY of the remaining offslte A.C. circuit by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours thereafter. Restore at least two offsite circuits to OPERABLE status within 72 hours or be in at least HOT STANDBY within the next 6 hours and in COLD SHUTDOWN within the following 30 hours. | |||
b.# With diesel generator set(s) 1A-A and/or 2A-A or 1B-B andlor 2B-B of the above required A.C. electrical power sources inoperable,* demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirement 4,8.1.1.1.a within one hour and at least once per 8 hours thereafter. and determining OPERABLE diesel generator sets are not inoperable due to common cause failure or performing Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours; restore at least four diesel generator sets to OPERABLE status within 7 days or be In at least HOT STANDBY within the next 6 hours and in COLD SHUTDOWN within the following 30 hours. | |||
# Required actions, to verify OPERABLE diesel generator sets are not inoperable due to common cause failure or perform SR 4.8.1. 1.2.a.4, shall be completed If this actIon is entered. | |||
No more than one diesel generator may be made simultaneously inoperable on a pre-planned basis for maintenance, modifications, or surveillance testing. | |||
@ Offsite circuits utilizing USST 2A and USST 2B as the normal power sources require CSST A and CSST C to be available as the altemate power sources via automatic transfer at the associated 6.9 kV Unit Boards. (CSST B can be substituted for CSST A or CSST C.) This Note remains in effect until November 30,2013, or until the USST modifications are Implemented on Units 1 and 2, whichever occurs first. | |||
SEaUOYAH - UNIT 1 3/48-1 Amendment No. 100, 132, 137,205,241,332 | |||
ELECTRICAL POWER SYSTEMS ACTION (Continued) | |||
: c. With one offslle circuit and one diesel generator set of the above required A.C. electrical power sources inoperable. demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirements 4.8. 1.1.1.a within one hour and at least once per 8 hours thereafter, and Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours; restore at least one of the Inoperable sources to OPERABLE status within 12 hours or be in at least HOT STANDBY within the next 6 hours and in COLD SHUTDOWN within the following 30 hours. | |||
: d. With two of the above required offsite A.C. circuits inoperable, demonstrate the OPERABILITY of 4 diesel generator sets by performing Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours, unless the diesel generator sets are already operating; restore at least one of the inoperable offslte sources to OPERABLE status within 24 hours or be in at least HOT STANDBY within the next 6 hours. | |||
: e. With either diesel generator sets 1A-A and/or 2A-A inoperable simultaneous with 1B-B and/or 2B-B, demonstrate the OPERABILITY of two offslte A.C. circuits by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours thereafter; restore at least 1) 1A-A and 2A-A or 2) 1B-B and 2B-B to OPERABLE status within 2 hours or be in at least HOT STANDBY within the next 6 hours and in COLD SHUTDOWN within the following 30 hours. | |||
: f. LCO 3.0.4.b is not applicable to diesel generators. | |||
SURVEILLANCE REQUIREMENTS 4.8.1.1.1 Each of the above required independent circuits between the offslte transmission network and the onsite Ciass 1E distribution system shall be: | |||
: a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability. | |||
: b. Demonstrated OPERABLE at least once per 18 months# by manually and automatically transferring the power supply to each 6.9 kV Unit Board## from the normal supply to the alternate supply. | |||
# For the 1A, 1B, 1C and 106.9 kV Unit Boards, this Surveillance shall not be performed in MODES 1 and 2. | |||
## Transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies. | |||
SEQUOYAH - UN IT 1 3/48*2 Amendment No. 100. 137, 184,205,228, 255, 301, 332 | |||
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50~328 SEQUOYAH NUCLEAR PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 325 License No. DPR-79 | |||
: 1. The Nuclear Regulatory Commission (the Commission) has found that: | |||
A The application for amendment by Tennessee Valley Authority (the licensee) dated May 23,2012, as supplemented by letter dated August 23,2012, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), | |||
and the Commission's rules and regulations set forth in Title 10 of the Gode of Federal Regulations (10 CFR) Chapter I; B. The facility will operate in conformity with the application, 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 wi" be conducted in compliance with the Commission's regulations; D. The issuance of this 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 Commission's regulations and a" applicable requirements have been satisfied. | |||
-2 | |||
: 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. DPR-79 is hereby amended to read as follows: | |||
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 325 ,are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications. | |||
: 3. This license amendment is effective as of its date of issuance, to be implemented prior to startup from Unit 2 fall 2012 refueling outage. | |||
FOR THE NUCLEAR REGULATORY COMMISSION | |||
~ i | |||
/ w9t&<-r& | |||
. Quichocho, Acting Chief (Zant Licensing Branch 11-2 ivision of Operating Reactor Licensing Office of Nuclear Reactor Regulation | |||
==Attachment:== | |||
Changes to the Facility Operating License and Technical Specifications Date of Issuance: October 31, 2012 | |||
ATTACHMENT TO LICENSE AMENDMENT NO. 325 FACILITY OPERATING LICENSE NO. DPR-79 DOCKET NO. 50-328 Replace Page 3 of Operating License DPR-79 with the attached page 3. | |||
Replace the following pages of the Appendix A Technical Specifications with the attached pages. | |||
The revised pages are identified by amendment number and contain marginal lines indicating the areas of change. | |||
REMOVE INSERT 3/48-1 3/48-1 3/4 8-2 3/48-2 | |||
. -3 (4) Pu/'luant to the Act and 10 CFR Parts 30, 40 and 70. to receive, posses.! end use in amounts as required any byproduct, louree or epeclal nuclear material without restriction to chemical or physical form, for sampl. analysis or instrument calibration or associated with radioacttve apparatus or components: | |||
and (5) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byprOduct and special nuclear materials as may be produced by the operatton of the Sequoyah and Watts Bar Unit 1 Nuclear Plants. | |||
C. Thls license shall be deemed to contain and Is subject to the condttlons speclfted in the Commlstlon's regulations set forth In 10 CFR Chapter I and is subject to all applicable provisions of ttle Act and to the rules, regulations, and orders of the Commission now or hereafter In effect: and Is subject to the additional conditions specified or Incorporated below: | |||
(1) Maximum Po,nr level The Tennetsee Valley AuthOrity is auth~rized to operate the facility at reactor core power levels not In excess of 3455 megawatts thermal. | |||
(2) Tercbnical Soecificltions The Technical Specifications contained In ~ppendlces A and B... revised through Amendment No. 325 are hereby incorporated Into this license. The licensee shall operate the facility In accordance with the Technical Specifications. | |||
(3) Initial Test Program The Tennessee Valley Authority shat! conduct the P08t-fuel-loading initial test program | |||
. (set forth In Section 14 of Tennessee Valley Authority's Final Safety Analysis Report, as amended), without making any major modifications of this program unless modific.tions have been identified and have received prior NRC approval. Major modifications are defined as: | |||
: a. Ellminatton of any test Identified tn Section 14 of TVA's Final Safety Analysis Report as amended as being eS8entlal; | |||
: b. Modification 01 test obJectiVes, methods or acceptance criteria for any test identified in Section 14 of TVA'. Final Safety Analysis Report as amended as being essential; | |||
: c. Performance of any test at power level different from there described; and Facility Operating license No. DPR-79 Nnendment No. 325 | |||
3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES OPERATING LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE: | |||
: a. Two physically Independent circuits between the offslte transmission network and the onsite Class 1E distribution system@, and | |||
: b. Four separate and independent diesel generator sets each with: | |||
: 1. Two diesels driving a common generator | |||
: 2. Two engine-mounted fuel tanks containing a minimum volume of 250 gallons of fuel, per tank | |||
: 3. A separate fuel storage system containing a minimum volume of 62,000 gallons of fuel, | |||
: 4. A separate fuel transfer pump, and | |||
: 5. A separate 125--volt D.C. distribution panel, 125--volt D.C. battery bank and associated charger. | |||
APPLICABILITY: MODES 1, 2, 3 and 4. | |||
ACTION: | |||
: a. With one offsite A.C. cirCUit of the above required AC. electrical power sources inoperable, demonstrate the OPERABILITY of the remaining offslte A.C. circuit by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours thereafter. Restore at least two offsite circuits to OPERABLE status within 72 hours or be in at least HOT STANDBY within the next 6 hours and In COLD SHUTDOWN within the following 30 hours. | |||
b.# With diesel generator set(s) 1A-A and/or 2A-A or 1B-B and/or 2B-B of the above required A.C. electrical power sources Inoperable,* demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours thereafter, and determining OPERABLE diesel generator sets are not Inoperable due to common cause failure or performing Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours; restore at least four diesel generator sets to OPERABLE status within 7 days or be In at least HOT STANDBY within the next 6 hours and In COLD SHUTDOWN within the following 30 hours. | |||
# Required actions, to verify OPERABLE diesel generator sets are not Inoperable due to common cause failure or perform SR 4.8.1.1.2.a.4, shall be completed if this action Is entered. | |||
* No more than one diesel generator may be made simultaneously inoperable on a pre-planned basis for maintenance, modifications, or surveillance testing. | |||
@ Offsite circuits utilizing USST 2A and USST 2B as the normal power sources require CSST A and CSST C to be available as the alternate power sources via automatic transfer at the associated 6.9 kV Unit Boards. (CSST B can be substituted for CSST A or CSST C.) This Note remains in effect until November 30, 2013, or until the USST modifications are Implemented on Units 1 and 2, whichever occurs first. | |||
SEQUOYAH - UNIT 2 3/48-1 Amendment No. 89.119,123,195,231. 325 | |||
ELECTRICAL POWER SYSTEMS ACTION (Continued) | |||
: c. With one offslte circuit and one diesel generator set of the above required A.C. electrical power sources inoperable, demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirements 4.8.1.1.1.a within one hour and at least once per 8 hours thereafter, and Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours; restore at least one of the inoperable sources to OPERABLE status within 12 hours or be in at least HOT STANDBY within the next 6 hours and In COLD SHUTDOWN within the following 30 hours. | |||
: d. With two of the above required offsite A.C. circuits inoperable, demonstrate the OPERABILITY of 4 diesel generator sets by performing Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours, unless the diesel generator sets are already operating; restore at least one of the inoperable offslte sources to OPERABLE status within 24 hours or be In at least HOT STANDBY within the next 6 hours. | |||
: e. With either diesel generator sets 1A-A and/or 2 A-A Inoperable simultaneous with 1B-B and/or 2B-B, demonstrate the OPERABILITY of two offsite A.C. circuits by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours thereafter; restore at least 1) 1A-A and 2A-A or 2) 1B-B and 2B-B to OPERABLE status within 2 hours or be in at least HOT STANDBY within the next 6 hours and In COLD SHUTDOWN within the following 30 hours. | |||
: f. LCO 3.0.4.b Is not applicable to diesel generators. | |||
SURVEILLANCE REQUIREMENTS 4.8.1.1.1 Each of the above required Independent circuits between the offsite transmission network and the onsite Class 1E distribution system shall be: | |||
: a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability. | |||
: b. Demonstrated OPERABLE at least once per 18 monthS# by manually and automatically transferring the power supply to each 6.9 kV Unit Board ## from the normal supply to the altemate supply. | |||
# For the 2A, 2B, 2C and 206.9 kV Unit Boards this Surveillance shall not be performed in MODES 1 and 2. | |||
## Transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and altemate power supplies. | |||
SEQUOYAH - UNIT 2 3/48-2 Amendment No. 89,123.176,195,219, 246, 290, 325 | |||
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 332 TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO. 325 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 | |||
==1.0 INTRODUCTION== | |||
By letter dated May 23,2012, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12146A385), as supplemented by letter dated August 23,2012 (ADAMS Accession No. ML12240A107), Tennessee Valley Authority (TVA or the licensee) requested amendments to Facility Operating License No. DPR-77 and No. DPR-79 for the Sequoyah Nuclear Plant (SON), Units 1 and 2. Specifically, the amendments requested changes to Technical Specification (TS) 3/4.8.1 to include a surveillance requirement (SR) to demonstrate the required offsite circuits OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 KiloVolt (kV) Unit Board from the normal supply to the alternate supply. The change is necessary as a result of planned modifications to the plant design and operating configuration that would install generator circuit breakers (GCBs) and new unit station service transformers (USSTs) to allow their use as an offsite power supply. This plant modification will eliminate a single point vulnerability for a dual unit trip. In addition, typographical errors on TS page 3/4 8-2 for SON, Units 1 and 2, and TS page 3/4 8-1 for Unit 1 would be corrected. | |||
The supplemental letter dated August 23,2012, provided additional information that clarified the application, and did not change the Nuclear Regulatory Commission (NRC or the Commission) staffs original proposed no significant hazards consideration determination as published in the Federal Register on July 24, 2012 (76 FR 43379). | |||
==2.0 REGULATORY EVALUATION== | |||
The regulatory requirements and guidance documents on which the NRC staff bases its acceptance are: | |||
* Title 10 of the Code of Federal Regulation (1 0 CFR), Part 50, Appendix A, General Design Criterion (GDC) 17, "Electric power systems," requires that an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety. The safety function for each system shall be to provide sufficient capacity and Enclosure | |||
-2 capability to assure that (1) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. The offsite power system is required to be supplied by two physically independent circuits that are designed and located so as to minimize, to the extent practical, the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. In addition, this criterion requires provisions to minimize the probability of losing electric power from the remaining electric power supplies as a result of loss of power from the unit, the offsite transmission network, or the onsite power supplies. | |||
* As required by 10 CFR Part 50, Appendix A, GDC-18, "Inspection and testing of electric power systems," electric power systems that are important to safety must be designed to permit appropriate periodic inspection and testing. | |||
* As required by 10 CFR Part 50, Appendix A, GDC-19, "Control room," "A control room shall be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions, including loss-of-coolant accidents.... Equipment at appropriate locations outside the control room shall be provided (1) with a design capability for prompt hot shutdown of the reactor, including necessary instrumentation and controls to maintain the unit in a safe condition during hot shutdown, and (2) with a potential capability for subsequent cold shutdown of the reactor through the use of suitable procedures." | |||
* As required by 10 CFR 50.36, "Technical Specifications," that TS shall be included by applicants for a license authorizing operation of a production or utilization facility. | |||
As required by 10 CFR 50.36(c), the TS includes items in five specific categories related to station operation. These categories are (1) Safety limits, limiting safety system settings, and limiting control settings, (2) Limiting conditions for operation (LCOs), (3) Surveillance requirements, (4) Design features, and (5) Administrative controls. The proposed changes to TS, discussed in this safety evaluation, are within the LCOs and the SRs categories. | |||
* 10 CFR 50.120, "Training and qualification of nuclear power plant personnel." | |||
* NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [Light-Water Reactor] Edition." | |||
* Chapter 13 addresses "Conduct of Operations," specific sub-chapters considered in this review were Chapters 13.2.1, "Reactor Operator Requalification Program; Reactor Operator Training," 13.5.1.1 "Administrative Procedures - General," including "Crane operation procedures," and 13.5.2.1, "Operating and Emergency Operating Procedures." | |||
* Chapter 18, provides review guidance for "Human Factors Engineering." | |||
* NUREG-1764, "Guidance for the Review of Changes to Human Actions." | |||
-3 | |||
* Generic Letter No. 82-33, "Supplement 1 to NUREG-0737 - Requirements for Emergency Response Capability." | |||
* NUREG-0700, "Human-System Interface Design Review Guidelines," Revision 2. | |||
* NUREG-0711, "Human Factors Engineering Program Review Model," Revision 2. | |||
* Information Notice 97-78, "Crediting of Operator Actions in Place of Automatic Actions and Modifications of Operator Actions, Including Response Times." | |||
==3.0 TECHNICAL EVALUATION== | |||
3.1 Brief Description A brief description of the pertinent portions of the SON, Units 1 and 2 electrical distribution system is provided below. The offsite power and onsite power systems are described in Sections 8.2 and 8.3 of the SON Updated Final Safety Analysis Report. | |||
Offsite power is supplied to the SON, Units 1 and 2 161 kV switchyard by eight dedicated transmission lines. The 161 kV switchyard is the preferred power supply for station loads during normal and accident conditions. From the 161 kV transformer yard, two electrically and physically separated circuits provide alternating current (AC) power, through step-down common station service transformers (CSSTs), to the 6.9 kV Unit Boards via the 6.9 kV Start Buses. Power is then supplied from the 6.9 kV Unit Boards to the 6.9 kV Shutdown Boards. Those two physically independent circuits between the offsite transmission network and the onsite Class 'I E distribution system are the preferred power supply. | |||
The Class 1E AC Distribution System supplies electrical power to two load groups, shared between the two units, with each load group powered by two independent Class 1E 6.9 kV Shutdown Boards. Train-A Shutdown Boards (1A-A and 2A-A) receive their normal power from CSST C. Train-B Shutdown Boards (1 B-B and 2B-B) receive their normal power from CSST A. | |||
CSST B is a spare transformer with two sets of secondary windings that can be used to power two Start Buses, with each Start Bus on a separate secondary winding. | |||
This lineup provides two immediate-access offsite circuits to each unit (one to each load group). | |||
On a failure of either CSST, offsite power continues to be provided to one load group by the other CSST, assuring that core cooling, containment integrity, and other vital functions are maintained. | |||
Therefore, transfers from one offsite power source to the other offsite power source are not necessary. In the event of a loss of offsite power (LOOP), or degraded voltage on the 6.9 kV Shutdown Boards, a dedicated Class 1E Diesel Generator (DG) supplies power to essential safety systems on its respective 6.9 kV Shutdown Board. | |||
3.2 Proposed Plant Modifications to the SON Electrical Distribution System The licensee plans to install GCBs and new USSTs with automatic load tap changers (LTCs). | |||
These modifications would allow an offsite power configuration in which the USSTs are capable of supplying the normal power, with automatic transfer to the alternate power supply provided by a CSST. GCBs would be installed in the isolated phase bus (IPB) between the main generator | |||
-4 and main bank transformers. Following plant modifications, both units can be powered from either the 500 kV grid or the 161 kV grid. | |||
Specifically, after implementation of the USST modifications on both units, each new USST would be aligned as the normal power supply to only one 6.9 kV Shutdown Board via the associated Unit Board. Train-A Shutdown Boards (1A-A and 2A-A) would receive their normal power from USST 1A and USST 2A respectively. Train-B Shutdown Boards (1 B-B and 2B-B) would receive their normal power from USST 1Band USST 2B, respectively. The design function of each USST is to provide unit power to its respective 6.9 kV Unit Boards and Class 1E 6.9 kV Shutdown Board. | |||
The new USSTs have higher impedance to limit fault current to below the 6.9 kV Unit Board circuit breaker rating. The USSTs have adequate capacity to support normal and accident loads. To support the offsite power requirements and improve normal operations, the USSTs are provided with automatic LTCs. The USST LTCs are similar to those installed on the current CSSTs. | |||
Power circuit breakers (PCBs) are located between the high side of the main bank transformers and the switchyard. On a trip of the PCBs, offsite power would automatically transfer to the alternate power supply from a CSST. Upon receipt of a PCB trip signal, the transfer occurs by opening the Unit Board normal supply breaker and closing the alternate supply breaker. The alternate supply breaker would not close until the normal supply breaker opens. This transfer typically occurs within six cycles. PCBs would trip open on a fault between the GCBs and the PCBs, or a failure of the GCBs to open on a valid command signal. | |||
During the time period between the SON, Unit 2 USST modification implementation and the SON, Unit 1 USST modification implementation, the output of USST 2A will be used as the normal power supply to 6.9 kV Shutdown Board 2A-A via Unit Board 2B, and the output of USST 2B will be used as the normal power supply to 6.9 kV Shutdown Board 2B-B via Unit Board 2C. CSST C will provide an alternate source of power for 6.9 kV Shutdown Board 2A-A via Unit Board 2B. | |||
CSST A will provide an alternate source of power for 6.9 kV Shutdown-Board 2B-B via Unit Board 2C. Power to 6.9 kV Shutdown Board 1A-A will continue to be supplied by CSST C via Start Bus 1B and Unit Board 1B. Power to 6.9 kV Shutdown Board 1B-B will continue to be supplied by CSST A via Start Bus 1A and Unit Board 1C. This lineup essentially requires three power sources (USST 2A12B, CSST A, and CSST C) to supply the normal and alternate offsite power circuits. Alternatively, the CSSTs can provide the two immediate access offsite circuits with no required transfer, consistent with the current licensing basis. | |||
After the SON, Unit 1 USST modification has been implemented, the normal offsite power alignment will be power supplied by the USSTs to the 6.9 kV Shutdown Boards via the 6.9 kV Unit Boards. Alternatively, power can be provided by one or more CSSTs via automatic transfer at the 6.9 kV Unit Boards on a trip of the PCBs. Other alignment configurations using other combinations of available USSTs and CSSTs will also be possible, as long as the alignments are consistent with the analyzed configurations, and comply with the requirements of GDC-17. | |||
3.3 NRC Staff's Evaluation The NRC staff reviewed the proposed change to the SON TS and the licensee's justification for the change. The licensee states that the change is necessary as a result of the planned modifications to the plant design and operating configuration. As described above, the plant modifications would install new USSTs and GCBs in the IPB between the generator and main | |||
-5 bank transformer. Under the new configuration, normal power will be supplied by the main generator through the USSTs and will allow use of the USSTs as an offsite power supply to the Class 'I E buses upon trip of the main generator. To determine the impact of plant modification on the SON electrical system, the NRC staff requested the licensee to provide a summary of the analysis performed to show that the voltage requirements to the plant safety system buses and components remain valid by the proposed modifications. In its response dated August 23,2012, the licensee confirmed that adequate voltage exists to start and accelerate all required loads consistent with the SON design basis requirements. Based on the response, the NRC staff determined that offsite power source would be acceptable when USSTs are being used to supply the unit boards. | |||
The NRC staff requested a summary of the transmission system study, including grid stability analysis, to determine if the SON offsite power systems (161 kV and 500 kV) would be adequate to meet GDC-17 requirements after the plant modifications. In its response dated August 23,2012, the licensee stated the load flow study showed that the transmission system minimum bus voltage acceptance criteria were met for both the normal operating conditions and loss-of-coolant accident conditions, and the bus voltage was sufficiently maintained to meet GDC-17 requirements. In addition, the transient stability study showed that there were no changes to the transmission system voltage recovery characteristics that would result in instability of the normally cleared faults or adversely affect operation of the SON in-plant undervoltage relays or DG system. The fault study analysis was also performed using various operating configurations and scenarios. The short circuit current ratings of the plant auxiliary electrical system breakers and buses would be adequate to support the proposed USST modifications. Based on the response, the NRC staff determined that the two offsite power sources from 161 kV and 500 kV systems for SON would remain in compliance with GDC-17. | |||
In the license amendment request (LAR), the licensee stated that the design function of each USST will be to provide unit power to its respective 6.9 kV Unit Boards and Class 1E 6.9 kV Shutdown Board. These new transformers would have a higher impedance to limit fault currents below the rating of the associated 6.9 kV Unit Board circuit breaker. The USST ratings would ensure adequate capacity for normal and accident loads and would include automatic LTCs to provide adequate 6.9 kV voltage regulation. The USST LTCs would be similar to those installed on the CSSTs and would have equivalent operating times. In its response to the NRC staff's questions regarding the failure modes of LTCs and capacity of the USSTs to support worst case design basis events, accidents, and abnormal operating occurrences, the licensee confirmed (1) the capacity of USSTs during transient accident loading and steady state accident loading, and (2) the capacity of USSTs for normal, anticipated operational occurrence, and accident loads is acceptable. The LTC failure modes were evaluated and no unacceptable conditions were identified. The periodic testing of the LTC controller would ensure that the device provides an acceptable response for the specified input. If the USST LTC fails before or during an accident, the associated 6.9 kV Shutdown Board would transfer to its dedicated DG when the board voltage reaches the degraded voltage relaying setpoint. High and low voltages are annunciated in the main control room (MCR). Based on this, the NRC staff determined that SON electrical system would remain in compliance with GDC-17. | |||
The NRC staff requested a detailed summary of the evaluation that shows the new GCB performance tests, ratings and its capabilities are verified consistent with the guidance provided in the Institute of Electrical and Electronics Engineers Standard (IEEE Std) C37.013-1997, "IEEE | |||
-6 Standard for AC High-Voltage Generator Circuit Breakers Rated on a Symmetrical Current Basis," | |||
and NUREG-0800, Section 8.2, Appendix A, "Guidelines for Generator Circuit Breakers/Load Break Switches." In its response dated August 23,2012, the licensee provided a description of design tests performed by the GCB supplier and summary of the results. The tests discussed are rated dielectric strength, load current switching, short circuit current rating, rated transient recovery voltage, short-time current-carrying capability, duty cycle capability, rated continuous current-carrying test, mechanical endurance life test, rated interrupting time, and short circuit current with delayed current zero. Based on the above, the NRC staff finds that the proposed GCBs have the capability of interrupting the system maximum available fault current and qualify as an immediate access offsite power circuit in accordance with GDC-17 and meet the guidance provided in IEEE Std C37.013 and NUREG-0800, Section 8.2, Appendix A. | |||
The NRC staff requested a summary of the bus transfer study, including a single failure of the bus transfer scheme or a worst-case failure of components in the plant auxiliary system. Based on the information provided by the licensee, the NRC staff finds that the guidance for bus transfers in American National Standards Institute C50.41 "Polyphase Induction Motors for Power Generating Stations" was used by the licensee and that the safety buses and loads would not be adversely affected by the transfer. | |||
The NRC staff also requested information regarding the impact on short circuit current ratings of the plant auxiliary electrical system buses and breakers as a result of the proposed modification. | |||
In its response, the licensee provided information to show that the short circuit ratings of medium voltage breakers and the switchgears would remain adequate to support the installation of the new USSTs. | |||
Based on the above, the NRC staff concludes that SON continues to meet the requirements specified in GDC-17. Implementation of the USST modifications and installation of GCBs will enable use of a USST as the normal power supply to a 6.9 kV Unit Board, with an automatic transfer to the alternate power supply from a CSST on a trip of the PCBs. Either the USSTs or a CSST will be available in a few seconds to support safe shutdown of both units in the event of a loss of all onsite power and the loss of the other offsite circuit. | |||
3.4 Changes to the SON Technical Specifications TS SR 4.8.1.1.1.a requires each of the above required independent circuits between the offsite transmission network and the onsite Class 1 E distribution system to be determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability. | |||
The licensee proposed changes to the SON TS 3/4.8.1 to include an SR to demonstrate the required offsite circuits operable at least once per 18 months by manually and automatically transferring the power supply of a 6.9 kV Unit Board from the normal supply to the alternate supply. | |||
Specifically, TS SR 4.8.1.1.1.b would be revised as follows with two notes. | |||
TS SR 4.8.1.1.1.b would state: | |||
Demonstrated OPERABLE at least once per 18 months by manually and automatically transferring the power supply to each 6.9 kV Unit Board from the normal supply to the alternate supply. | |||
-7 The first note would preclude performance of the SR on the associated unit's 6.9 kV Unit Boards in MODES 1 and 2. | |||
For Unit 1, this note would state: | |||
For the 1A, 1B, 1C, and 1D 6.9 kV Unit Boards, this Surveillance shall not be performed in MODES 1 and 2. | |||
For Unit 2, this note would state: | |||
For the 2A, 2B, 2C, and 2D 6.9 kV Unit Boards, this Surveillance shall not be performed in MODES 1 and 2. | |||
The second note would specify that verification of transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies. | |||
For Units 1 and 2, this note would state: | |||
Transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies. | |||
As stated in the licensee's submittal, the purpose of SR 4.8.1.1.1.b is to ensure that the power feeds, including those to the shutdown boards, would be transferred to a qualified offsite power circuit in accordance with GDC-17. The NRC staff reviewed the above additional SR 4.8.1.1.1.b requirement and the LAR and noted that following plant modifications, offsite power will normally be supplied from the USSTs to the 6.9 kV Unit Boards, and will automatically transfer to the alternate power supply to at least one circuit from the CSSTs on a trip of the PCBs. The transfer occurs when the Unit Board normal supply breaker opens and the alternate supply breaker closes. | |||
The alternate supply breaker will not close until the normal supply breaker opens. Implementation of these design changes requires the licensee to demonstrate the capability to transfer the power supply to a 6.9 kV Unit Board from the normal supply to the alternate supply. The proposed addition of TS SR 4.8.1.1.1.b requirement to demonstrate that the required offsite circuits are OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 kV Unit Board from the normal supply to the alternate supply meets the requirements specified in 10 CFR 50.36(c) and GDC-18. | |||
The NRC staff reviewed the two notes added to this SR as discussed above. The LAR states that this surveillance is only performed on 6.9 kV Unit Boards associated with the unit not in MODE 1 or 2. Restricting performance of the SR to MODE 3, 4, 5 or 6 will minimize the potential for inducing an electrical distribution subsystem perturbation that could result in a unit trip or actuation of an engineered safety feature (ESF) system. Perturbations to the electrical distribution subsystems are further minimized during performance of the SR on a 6.9 kV Unit Board by transferring the associated 6.9 kV Shutdown Board to the alternate feed (another 6.9 kV Unit Board that is not being tested) prior to performing the SR. Since the 6.9 kV Unit Board surveillance is performed on an unloaded board, it will not initiate a perturbation in an electrical distribution system that could challenge a plant safety related system, or challenge steady state conditions to the unit in operation. If the alignment of the associated 6.9 kV Shutdown Board to the alternate feed results in an inoperable offsite circuit, the Actions of LCO 3.8.1.1 will be entered | |||
-8 and the provisions of LCO 3.0.5 will be invoked. By invoking LCO 3.0.5, the affected safety related equipment may be considered operable for the purpose of satisfying their applicable LCOs. | |||
The licensee states that prior to performance of the SR, safety related equipment redundant to the equipment powered from the affected 6.9 kV Shutdown Board will be verified operable, as required by LCO 3.0.5. Failure of this surveillance will not challenge or cause an operational transient or challenge to plant safety systems for the unit in operation. The ability of the 6.9 kV Shutdown Board to transfer to the DG will not be inhibited should the ability of the associated 6.9 kV Unit Board to automatically or manually transfer to the alternate supply breaker not be functional. The LOOP circuits will still automatically strip the board and allow the diesel starting and loading sequence to occur providing power to the ESF systems as designed. The NRC staff noted that when the surveillance is being performed on the 6.9 kV Unit Board, its associated Shutdown Board loads will be transferred to another Unit Board that is not being tested prior to performing the surveillance, therefore the test has no impact on plant equipment. | |||
Based on the above, the NRC staff determined that restricting performance of the SR to MODE 3, 4, 5 or 6 will minimize the potential for inducing an electrical distribution subsystem perturbation and is consistent with guidance provided in NUREG-1431, "Standard Technical Specifications Westinghouse Plants," as introduced in NRC approved Technical Specification Task Force (TSTF) change TSTF-283, Revision 3. | |||
The second note specifies that automatic transfer from the normal supply to the alternate supply is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies. | |||
The NRC staff reviewed this note and determined that the note is clarifying the intent of the SR and is acceptable. | |||
The requirements for offsite AC power sources are specified in SQN TS 3/4.8.1, "AC Sources, Operating." LCO 3.8.1.1.a requires two physically independent circuits between the offsite transmission network and the onsite Class 1E distribution system to be OPERABLE in MODES 1, 2,3, and 4. The NRC staff expressed concerns regarding the intermediate phase of the modifications (the time period between completion of the modifications in Unit 2 and the completion of modifications in Unit 1). Specifically, the NRC staff asked the licensee to clarify which independent power sources are required to be OPERABLE to meet the TS 3/4.8.1 requirement (two physically independent circuits between the offsite transmission network and the onsite Class 1E distribution system) until the Unit 1 USST modifications are completed. In its response dated August 23, 2012, the licensee modified TS 3/4.8.1, AC Sources, 3.8.1.1.a by adding a note that specifies: | |||
Offsite circuits utilizing USST 2A and USST 2B as the normal power sources require CSST A and CSST C to be available as the alternate power sources via automatic transfer at the associated 6.9 kV Unit Boards. (CSST B can be substituted for CSST A or CSST C). | |||
This Note remains in effect until November 30, 2013, or until the USST modifications are implemented on Units 1 and 2, whichever occurs first. | |||
The NRC staff found adding the note to TS LCO 3.8.1.1.a is an acceptable method to clarify the circuits that are required to be OPERABLE per the LCO until the modifications are fully implemented at both units. | |||
Other changes proposed in the TSs are administrative in nature and does not require the NRC | |||
- 9 staff's review. | |||
3.5 Description of Operator Actiones) and Assessed Safetv Significance The operator action supporting this proposed TS revision is the manual transfer of the power supply to a 6.9 kV Unit Board from the normal supply to the alternate supply. This action is done in the mild environment of the MCR. This is a backup action to an automatic transfer system. The cue for the initiation of the action is annunciation of trouble in the automatic transfer system, or by monitoring available electrical distribution instrumentation. Controls are available both in the MCR and at the local control stations. This action is not credited in any design-basis accident (DBA) and is not time-critical. The original design of SQN included a surveillance almost identical to the one being proposed in this LAR. | |||
In accordance with the generic risk categories established in Appendix A to NUREG-1764, this task sequence is considered "low or no risk" due to the fact that it is not credited in any DBA. | |||
However, because of its association with the loss of off-site power, the NRC staff performed a general human factors review (Le., the least stringent of the levels of graded review possible under the guidance of NUREG-1764). | |||
3.6 Analysis The licensee has done an impact analysis on the plant modification supporting this LAR using TVA procedure NPG-SPP-09.3.1, "Guidelines for Preparation of Design Inputs and Change Impact Screen." The NRC staff finds that because the licensee's analysis was performed using a controlled administrative process, and because the results (see below) are reasonable, the analysis performed is acceptable for a low risk operator action such as that proposed in this LAR. | |||
3.7 Design of Human-System Interfaces, Procedures. and Training 3.7.1 Human-System Interfaces Various new controls, displays, and annunciators will be added to the MCR and local control stations. No change to the safety parameter display system was needed. | |||
3.7.2 Procedures The licensee reviewed annunciator response procedures, general operating procedures, system operating procedures, abnormal operating procedures, emergency operating procedures, surveillance instructions, technical instructions, and periodic instructions. Among those reviewed, many procedures were identified as requiring development or revision to reflect the pending modification. For example, abnormal operating procedure (AOP) AOP-P.01, "Loss of Offsite Power," has been identified for revision to address restoration of offsite power. Similar review efforts are planned for the maintenance procedures. | |||
3.7.3 Training The TVA administrative processes require that training needs assessment be performed on new and revised procedures. Because procedure changes are being made for the TS revision and | |||
-10 plant modification, they are required to be evaluated for potential training needs of licensed operators, nonlicensed operators, and maintenance personnel. Training material will be developed and presented for any identified training needs. It is anticipated that the new TS changes and procedure changes will require approximately 3 hours of classroom training. In addition, the licensee stated that walk-down(s) of new equipment may be conducted to support the training and procedure changes. Task performance evaluations may also be required on the new tasks for non-licensed operators. The licensee anticipates that the additional training will be given to job incumbents and incorporated into the initial operator training. | |||
The licensee also anticipates that a remote function will be added to the simulator model to emulate the new Unit 2 configuration for GCB trips and interlocks, as well as use of the USSTs as an electrical power source. Because the simulator is based on Unit 1, the licensee plans to modify the simulator to reflect the changes being made to the Unit 1 control room, in conjunction with the Unit 1 USSTlGCB modification. | |||
3.7.4 Human Action Verification Because the USSTlGCB plant modification will result in a revision to AOP-P.01, and possibly emergency operating procedures (EOPs), the governing processes at SON require the procedures to be verified and validated. Per the controlling procedures, revised procedures may be walked down, as needed, to verify accuracy and usability. | |||
3.8 Summary The proposed LAR was evaluated by the NRC staff to determine whether applicable regulations and requirements continue to be met. It was determined that the proposed changes do not require any exemptions or relief from regulatory requirements. Applicable regulatory requirements will continue to be met, adequate defense-in-depth will be maintained, and sufficient safety margins will be maintained. The NRC staff concludes that the proposed changes will not impact the licensee's compliance to the regulatory requirements of 10 CFR 50.36(c) and GOCs 17 and 18. | |||
Therefore, the proposed changes are acceptable. | |||
Based on the licensee's impact analysis done for the GCB/USST plant modification, the NRC staff finds that the planned revisions to procedures, training, and the human-system interface design supporting the proposed TS change, and the planned AOP and EOP verification and validation will provide a high level of confidence that SON operators will be able to reliably perform the manual actions proposed in this LAR. Therefore, the NRC staff finds this LAR acceptable from the human performance perspective. | |||
The licensee included in its application, the revised TS Bases to be implemented with the TS changes. The NRC staff finds that the TS Bases Control Program is the appropriate process for updating the affected TS Bases pages and has, therefore, not included the affected Bases pages with these amendments. | |||
==4.0 STATE CONSULTATION== | |||
In accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendment. The State official had no comments. | |||
- 11 | |||
==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 and change surveillance requirements. 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 (77 FR 43379, July 24, 2012). 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 these amendments will not be inimical to the common defense and security or to the health and safety of the public. | |||
Principal Contributors: R. Mathew A Matos-Marin G. Lapinsky Date: October 31,2012 | |||
October 31,2012 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 | |||
==SUBJECT:== | |||
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 -ISSUANCE OF AMENDMENTS TO REVISE THE TECHNICAL SPECIFICATIONS 3/4.8.1 IN SUPPORT OF UNIT STATION SERVICE TRANSFORMER MODIFICATION (TS- SQN-12-01) | |||
(TAC NOS. ME8772 AND ME8773) | |||
==Dear Mr. Shea:== | |||
The Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment No. 332 to Facility Operating License No. DPR-77 and Amendment No. 325 to Facility Operating License No. DPR-79 for the Sequoyah Nuclear Plant, Units 1 and 2, respectively. These amendments are in response to your application dated May 23, 2012, as supplemented by letter dated August 23,2012. The amendments request changes to Technical Specification 3/4.8.1 to include a surveillance requirement to demonstrate the required offsite circuits OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 KiloVolt Unit Board from the normal supply to the alternate supply. This change is necessary as a result of the planned modifications to the plant design and operating configuration that would install generator circuit breakers and new unit station service transformers to allow their use as an offsite power supply. | |||
A copy of the Safety Evaluation is also enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice. | |||
Sincerely, IRA! | |||
Siva P. Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 | |||
==Enclosures:== | |||
: 1. Amendment No. 332 to DPR-77 | |||
: 2. Amendment No. 325 to DPR-79 | |||
: 3. Safety Evaluation cc w/enclosures: Distribution via Listserv Distribution: | |||
Public RidsNrrDorlDpr RidsNrrLABClayton RidsAcrsAcnw MailCTR RidsNrrDssStsb LPL2*2 R/F RidsNrrDorlLpl2*2 RidsOgcRp RidSRgn2MailCenter RidsNrrPMSequoyah RidsNrrDraAhpb RidsNrrDssSnpb RidsNrrDeEeeb RidsNrrDraApla R. Mathew, NRR G. Lapinsky, NRR G. Waig, NRR A. Matos*Marin. NRR o | |||
ADAMS Accession No. ML12286A 78. *Ssymemo OFFICE LPL2*2/PM LPL2-2/LA B/BC AHPB/BC APLAlBC NAME SLingam BClayton dersen* UShoop* SDinsmore for DHarrison DATE 10/15112 10115/12 09117/12 10/01/12 10/16/12 OFFICE SNPB/BC STSB/BC OGC NLO LPLII-21BC (A) | |||
NAME AMendiola GWaig for LSubin JQuichocho RElUolt wI comment DATE 10/24112 10/15/12 10/22/12 10131112 OFFICIAL RECORD COpy}} |
Latest revision as of 22:21, 11 November 2019
ML12286A078 | |
Person / Time | |
---|---|
Site: | Sequoyah ![]() |
Issue date: | 10/31/2012 |
From: | Siva Lingam Plant Licensing Branch II |
To: | James Shea Tennessee Valley Authority |
Lingam, Siva | |
References | |
TAC ME8772, TAC ME8773 | |
Download: ML12286A078 (25) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 October 31,2012 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 -ISSUANCE OF AMENDMENTS TO REVISE THE TECHNICAL SPECIFICATIONS 3/4.8.1 IN SUPPORT OF UNIT STATION SERVICE TRANSFORMER MODIFICATION (TS- SQN-12-01)
(TAC NOS. ME8772 AND ME8773)
Dear Mr. Shea:
The Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment No. 332 to Facility Operating License No. DPR-77 and Amendment No. 325 to Facility Operating License No. DPR-79 for the Sequoyah Nuclear Plant, Units 1 and 2, respectively. These amendments are in response to your application dated May 23, 2012, as supplemented by letter dated August 23, 2012. The amendments request changes to Technical Specification 3/4.8.1 to include a surveillance requirement to demonstrate the required offsite circuits OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 KiloVolt Unit Board from the normal supply to the alternate supply. This change is necessary as a result of the planned modifications to the plant design and operating configuration that would install generator circuit breakers and new unit station service transformers to allow their use as an offsite power supply.
A copy of the Safety Evaluation is also enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice.
Sincerely,
~<f'~
Siva P. Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328
Enclosures:
- 1. Amendment No. 332 to DPR*77
- 2. Amendment No. 325 to DPR-79
- 3. Safety Evaluation cc w/enclosures: Distribution via Listserv
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-327 SEQUOYAH NUCLEAR PLANT, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 332 License No. DPR-77
- 1. The Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment by Tennessee Valley Authority (the licensee) dated May 23,2012, as supplemented by letter dated August 23,2012, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) I and the Commission's rules and regulations set forth in Title 10 of the Gode of Federal Regulations, Chapter I; B. The facility will operate in conformity with the application, 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 Commission's regulations; D. The issuance of this 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 Commission's regulations and all applicable requirements have been satisfied.
-2
- 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. DPR-77 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 332, I are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.
- 3. This license amendment is effective as of its date of issuance, to be implemented prior to startup from Unit 2 fall 2012 refueling outage.
FOR THE NUCLEAR REGULATORY COMMISSION
~44'~~
le~. QUichocho, Acting Chief lant licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Facility Operating License and Technical Specifications Date of Issuance: October 31,2012
ATTACHMENT TO LICENSE AMENDMENT NO. 332 FACILITY OPERATING LICENSE NO. DPR-77 DOCKET NO. 50-327 Replace Page 3 of Operating License DPR-77 with the attached page 3.
Replace the following pages of the Appendix A Technical Specifications with the attached pages.
The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
REMOVE INSERT 3/48-1 3/48-1 3/4 8-2 3/4 8-2
(4) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required. any byproduct, source or special nuclear material without restriction to chemical or physical form, for sample analysis. instrument calibration or associated with radioactive apparatus or components; and (5) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate.
such byproduct and special nuclear materials as may be produced by the operation of the Sequoyah and Watts Bar Unit 1 Nuclear Plants.
C. This license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth In 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules. regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions speCified or incorporated below:
(1) Maximum POwer Level The Tennessee Valley Authority is authorized to operate the facility at reactor core power levels not in excess of 3455 megawatts th~rmal.
(2) Technical Specifications The Technical SpAr:ifications contained in Appendices A and S, as revised through Amendment No. 332 are hereby Incorporated into this license. The licensee shall operate the facility in accordance with the Technical Specifications.
(3) Initiar Test Program The Tennessee Valley Authority shall conduct the post-fuel-Ioading initial test program (set forth in Section 14 of Tennessee Vaney Authority's Final Safety Analysis Report.
as amended). without making any major modifications of this program unless modifications have been identified and have received prior NRC approval. Major modifications are defined as:
- a. Elimination of any test identified in Section 14 of TVA's Final Safety AnalySis Report as amended as being essential;
- b. Modification of test objectives, methods or acceptance criteria for any test identified in Section 14 of TVA's Final Safety Analysis Report as amended as being essential;
- c. Performance of any test at power level different from there described; and Facility Operating License No. DPR-77 Amendment No. 332
3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES OPERA"rlNG LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE:
- a. Two physically independent circuits between the offsite transmission network and the onsite Class 1E distributIon system@, and
- b. Four separate and independent diesel generator sets each with:
- 1. Two diesels driving a common generator
- 2. Two engine-mounted fuel tanks containing a minimum volume of 250 gallons of fuel, per tank
- 3. A separate fuel storage system containing a minimum volume of 62,000 gallons of fuel,
- 4. A separate fuel transfer pump, and
- 5. A separate 125-voH D.C. distribution panel, 125-volt D.C.
battery bank and associated charger, APPLICABILITY: MODES 1, 2, 3 and 4.
ACTION:
- a. With one offsite A.C. circuit of the above required A.C. electrical power source inoperable, demonstrate the OPERABILIlY of the remaining offslte A.C. circuit by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter. Restore at least two offsite circuits to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
b.# With diesel generator set(s) 1A-A and/or 2A-A or 1B-B andlor 2B-B of the above required A.C. electrical power sources inoperable,* demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirement 4,8.1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter. and determining OPERABLE diesel generator sets are not inoperable due to common cause failure or performing Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; restore at least four diesel generator sets to OPERABLE status within 7 days or be In at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- Required actions, to verify OPERABLE diesel generator sets are not inoperable due to common cause failure or perform SR 4.8.1. 1.2.a.4, shall be completed If this actIon is entered.
No more than one diesel generator may be made simultaneously inoperable on a pre-planned basis for maintenance, modifications, or surveillance testing.
@ Offsite circuits utilizing USST 2A and USST 2B as the normal power sources require CSST A and CSST C to be available as the altemate power sources via automatic transfer at the associated 6.9 kV Unit Boards. (CSST B can be substituted for CSST A or CSST C.) This Note remains in effect until November 30,2013, or until the USST modifications are Implemented on Units 1 and 2, whichever occurs first.
SEaUOYAH - UNIT 1 3/48-1 Amendment No. 100, 132, 137,205,241,332
ELECTRICAL POWER SYSTEMS ACTION (Continued)
- c. With one offslle circuit and one diesel generator set of the above required A.C. electrical power sources inoperable. demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirements 4.8. 1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, and Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />; restore at least one of the Inoperable sources to OPERABLE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- d. With two of the above required offsite A.C. circuits inoperable, demonstrate the OPERABILITY of 4 diesel generator sets by performing Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, unless the diesel generator sets are already operating; restore at least one of the inoperable offslte sources to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
- e. With either diesel generator sets 1A-A and/or 2A-A inoperable simultaneous with 1B-B and/or 2B-B, demonstrate the OPERABILITY of two offslte A.C. circuits by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least 1) 1A-A and 2A-A or 2) 1B-B and 2B-B to OPERABLE status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- f. LCO 3.0.4.b is not applicable to diesel generators.
SURVEILLANCE REQUIREMENTS 4.8.1.1.1 Each of the above required independent circuits between the offslte transmission network and the onsite Ciass 1E distribution system shall be:
- a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability.
- b. Demonstrated OPERABLE at least once per 18 months# by manually and automatically transferring the power supply to each 6.9 kV Unit Board## from the normal supply to the alternate supply.
- For the 1A, 1B, 1C and 106.9 kV Unit Boards, this Surveillance shall not be performed in MODES 1 and 2.
- Transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies.
SEQUOYAH - UN IT 1 3/48*2 Amendment No. 100. 137, 184,205,228, 255, 301, 332
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50~328 SEQUOYAH NUCLEAR PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 325 License No. DPR-79
- 1. The Nuclear Regulatory Commission (the Commission) has found that:
A The application for amendment by Tennessee Valley Authority (the licensee) dated May 23,2012, as supplemented by letter dated August 23,2012, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),
and the Commission's rules and regulations set forth in Title 10 of the Gode of Federal Regulations (10 CFR) Chapter I; B. The facility will operate in conformity with the application, 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 wi" be conducted in compliance with the Commission's regulations; D. The issuance of this 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 Commission's regulations and a" applicable requirements have been satisfied.
-2
- 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. DPR-79 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 325 ,are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.
- 3. This license amendment is effective as of its date of issuance, to be implemented prior to startup from Unit 2 fall 2012 refueling outage.
FOR THE NUCLEAR REGULATORY COMMISSION
~ i
/ w9t&<-r&
. Quichocho, Acting Chief (Zant Licensing Branch 11-2 ivision of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Facility Operating License and Technical Specifications Date of Issuance: October 31, 2012
ATTACHMENT TO LICENSE AMENDMENT NO. 325 FACILITY OPERATING LICENSE NO. DPR-79 DOCKET NO. 50-328 Replace Page 3 of Operating License DPR-79 with the attached page 3.
Replace the following pages of the Appendix A Technical Specifications with the attached pages.
The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
REMOVE INSERT 3/48-1 3/48-1 3/4 8-2 3/48-2
. -3 (4) Pu/'luant to the Act and 10 CFR Parts 30, 40 and 70. to receive, posses.! end use in amounts as required any byproduct, louree or epeclal nuclear material without restriction to chemical or physical form, for sampl. analysis or instrument calibration or associated with radioacttve apparatus or components:
and (5) Pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byprOduct and special nuclear materials as may be produced by the operatton of the Sequoyah and Watts Bar Unit 1 Nuclear Plants.
C. Thls license shall be deemed to contain and Is subject to the condttlons speclfted in the Commlstlon's regulations set forth In 10 CFR Chapter I and is subject to all applicable provisions of ttle Act and to the rules, regulations, and orders of the Commission now or hereafter In effect: and Is subject to the additional conditions specified or Incorporated below:
(1) Maximum Po,nr level The Tennetsee Valley AuthOrity is auth~rized to operate the facility at reactor core power levels not In excess of 3455 megawatts thermal.
(2) Tercbnical Soecificltions The Technical Specifications contained In ~ppendlces A and B... revised through Amendment No. 325 are hereby incorporated Into this license. The licensee shall operate the facility In accordance with the Technical Specifications.
(3) Initial Test Program The Tennessee Valley Authority shat! conduct the P08t-fuel-loading initial test program
. (set forth In Section 14 of Tennessee Valley Authority's Final Safety Analysis Report, as amended), without making any major modifications of this program unless modific.tions have been identified and have received prior NRC approval. Major modifications are defined as:
- a. Ellminatton of any test Identified tn Section 14 of TVA's Final Safety Analysis Report as amended as being eS8entlal;
- b. Modification 01 test obJectiVes, methods or acceptance criteria for any test identified in Section 14 of TVA'. Final Safety Analysis Report as amended as being essential;
- c. Performance of any test at power level different from there described; and Facility Operating license No. DPR-79 Nnendment No. 325
3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES OPERATING LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE:
- a. Two physically Independent circuits between the offslte transmission network and the onsite Class 1E distribution system@, and
- b. Four separate and independent diesel generator sets each with:
- 1. Two diesels driving a common generator
- 2. Two engine-mounted fuel tanks containing a minimum volume of 250 gallons of fuel, per tank
- 3. A separate fuel storage system containing a minimum volume of 62,000 gallons of fuel,
- 4. A separate fuel transfer pump, and
- 5. A separate 125--volt D.C. distribution panel, 125--volt D.C. battery bank and associated charger.
APPLICABILITY: MODES 1, 2, 3 and 4.
ACTION:
- a. With one offsite A.C. cirCUit of the above required AC. electrical power sources inoperable, demonstrate the OPERABILITY of the remaining offslte A.C. circuit by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter. Restore at least two offsite circuits to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and In COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
b.# With diesel generator set(s) 1A-A and/or 2A-A or 1B-B and/or 2B-B of the above required A.C. electrical power sources Inoperable,* demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, and determining OPERABLE diesel generator sets are not Inoperable due to common cause failure or performing Surveillance Requirement 4.8.1.1.2.a.4 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; restore at least four diesel generator sets to OPERABLE status within 7 days or be In at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and In COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- Required actions, to verify OPERABLE diesel generator sets are not Inoperable due to common cause failure or perform SR 4.8.1.1.2.a.4, shall be completed if this action Is entered.
- No more than one diesel generator may be made simultaneously inoperable on a pre-planned basis for maintenance, modifications, or surveillance testing.
@ Offsite circuits utilizing USST 2A and USST 2B as the normal power sources require CSST A and CSST C to be available as the alternate power sources via automatic transfer at the associated 6.9 kV Unit Boards. (CSST B can be substituted for CSST A or CSST C.) This Note remains in effect until November 30, 2013, or until the USST modifications are Implemented on Units 1 and 2, whichever occurs first.
SEQUOYAH - UNIT 2 3/48-1 Amendment No. 89.119,123,195,231. 325
ELECTRICAL POWER SYSTEMS ACTION (Continued)
- c. With one offslte circuit and one diesel generator set of the above required A.C. electrical power sources inoperable, demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirements 4.8.1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter, and Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />; restore at least one of the inoperable sources to OPERABLE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and In COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- d. With two of the above required offsite A.C. circuits inoperable, demonstrate the OPERABILITY of 4 diesel generator sets by performing Surveillance Requirement 4.8.1.1.2.a.4 within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, unless the diesel generator sets are already operating; restore at least one of the inoperable offslte sources to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be In at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
- e. With either diesel generator sets 1A-A and/or 2 A-A Inoperable simultaneous with 1B-B and/or 2B-B, demonstrate the OPERABILITY of two offsite A.C. circuits by performing Surveillance Requirement 4.8.1.1.1.a within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least 1) 1A-A and 2A-A or 2) 1B-B and 2B-B to OPERABLE status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and In COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- f. LCO 3.0.4.b Is not applicable to diesel generators.
SURVEILLANCE REQUIREMENTS 4.8.1.1.1 Each of the above required Independent circuits between the offsite transmission network and the onsite Class 1E distribution system shall be:
- a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability.
- b. Demonstrated OPERABLE at least once per 18 monthS# by manually and automatically transferring the power supply to each 6.9 kV Unit Board ## from the normal supply to the altemate supply.
- For the 2A, 2B, 2C and 206.9 kV Unit Boards this Surveillance shall not be performed in MODES 1 and 2.
- Transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and altemate power supplies.
SEQUOYAH - UNIT 2 3/48-2 Amendment No. 89,123.176,195,219, 246, 290, 325
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 332 TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO. 325 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328
1.0 INTRODUCTION
By letter dated May 23,2012, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12146A385), as supplemented by letter dated August 23,2012 (ADAMS Accession No. ML12240A107), Tennessee Valley Authority (TVA or the licensee) requested amendments to Facility Operating License No. DPR-77 and No. DPR-79 for the Sequoyah Nuclear Plant (SON), Units 1 and 2. Specifically, the amendments requested changes to Technical Specification (TS) 3/4.8.1 to include a surveillance requirement (SR) to demonstrate the required offsite circuits OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 KiloVolt (kV) Unit Board from the normal supply to the alternate supply. The change is necessary as a result of planned modifications to the plant design and operating configuration that would install generator circuit breakers (GCBs) and new unit station service transformers (USSTs) to allow their use as an offsite power supply. This plant modification will eliminate a single point vulnerability for a dual unit trip. In addition, typographical errors on TS page 3/4 8-2 for SON, Units 1 and 2, and TS page 3/4 8-1 for Unit 1 would be corrected.
The supplemental letter dated August 23,2012, provided additional information that clarified the application, and did not change the Nuclear Regulatory Commission (NRC or the Commission) staffs original proposed no significant hazards consideration determination as published in the Federal Register on July 24, 2012 (76 FR 43379).
2.0 REGULATORY EVALUATION
The regulatory requirements and guidance documents on which the NRC staff bases its acceptance are:
- Title 10 of the Code of Federal Regulation (1 0 CFR), Part 50, Appendix A, General Design Criterion (GDC) 17, "Electric power systems," requires that an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety. The safety function for each system shall be to provide sufficient capacity and Enclosure
-2 capability to assure that (1) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. The offsite power system is required to be supplied by two physically independent circuits that are designed and located so as to minimize, to the extent practical, the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. In addition, this criterion requires provisions to minimize the probability of losing electric power from the remaining electric power supplies as a result of loss of power from the unit, the offsite transmission network, or the onsite power supplies.
- As required by 10 CFR Part 50, Appendix A, GDC-18, "Inspection and testing of electric power systems," electric power systems that are important to safety must be designed to permit appropriate periodic inspection and testing.
- As required by 10 CFR Part 50, Appendix A, GDC-19, "Control room," "A control room shall be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions, including loss-of-coolant accidents.... Equipment at appropriate locations outside the control room shall be provided (1) with a design capability for prompt hot shutdown of the reactor, including necessary instrumentation and controls to maintain the unit in a safe condition during hot shutdown, and (2) with a potential capability for subsequent cold shutdown of the reactor through the use of suitable procedures."
- As required by 10 CFR 50.36, "Technical Specifications," that TS shall be included by applicants for a license authorizing operation of a production or utilization facility.
As required by 10 CFR 50.36(c), the TS includes items in five specific categories related to station operation. These categories are (1) Safety limits, limiting safety system settings, and limiting control settings, (2) Limiting conditions for operation (LCOs), (3) Surveillance requirements, (4) Design features, and (5) Administrative controls. The proposed changes to TS, discussed in this safety evaluation, are within the LCOs and the SRs categories.
- 10 CFR 50.120, "Training and qualification of nuclear power plant personnel."
- NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [Light-Water Reactor] Edition."
- Chapter 13 addresses "Conduct of Operations," specific sub-chapters considered in this review were Chapters 13.2.1, "Reactor Operator Requalification Program; Reactor Operator Training," 13.5.1.1 "Administrative Procedures - General," including "Crane operation procedures," and 13.5.2.1, "Operating and Emergency Operating Procedures."
- Chapter 18, provides review guidance for "Human Factors Engineering."
- NUREG-1764, "Guidance for the Review of Changes to Human Actions."
-3
- Generic Letter No. 82-33, "Supplement 1 to NUREG-0737 - Requirements for Emergency Response Capability."
- NUREG-0700, "Human-System Interface Design Review Guidelines," Revision 2.
- NUREG-0711, "Human Factors Engineering Program Review Model," Revision 2.
- Information Notice 97-78, "Crediting of Operator Actions in Place of Automatic Actions and Modifications of Operator Actions, Including Response Times."
3.0 TECHNICAL EVALUATION
3.1 Brief Description A brief description of the pertinent portions of the SON, Units 1 and 2 electrical distribution system is provided below. The offsite power and onsite power systems are described in Sections 8.2 and 8.3 of the SON Updated Final Safety Analysis Report.
Offsite power is supplied to the SON, Units 1 and 2 161 kV switchyard by eight dedicated transmission lines. The 161 kV switchyard is the preferred power supply for station loads during normal and accident conditions. From the 161 kV transformer yard, two electrically and physically separated circuits provide alternating current (AC) power, through step-down common station service transformers (CSSTs), to the 6.9 kV Unit Boards via the 6.9 kV Start Buses. Power is then supplied from the 6.9 kV Unit Boards to the 6.9 kV Shutdown Boards. Those two physically independent circuits between the offsite transmission network and the onsite Class 'I E distribution system are the preferred power supply.
The Class 1E AC Distribution System supplies electrical power to two load groups, shared between the two units, with each load group powered by two independent Class 1E 6.9 kV Shutdown Boards. Train-A Shutdown Boards (1A-A and 2A-A) receive their normal power from CSST C. Train-B Shutdown Boards (1 B-B and 2B-B) receive their normal power from CSST A.
CSST B is a spare transformer with two sets of secondary windings that can be used to power two Start Buses, with each Start Bus on a separate secondary winding.
This lineup provides two immediate-access offsite circuits to each unit (one to each load group).
On a failure of either CSST, offsite power continues to be provided to one load group by the other CSST, assuring that core cooling, containment integrity, and other vital functions are maintained.
Therefore, transfers from one offsite power source to the other offsite power source are not necessary. In the event of a loss of offsite power (LOOP), or degraded voltage on the 6.9 kV Shutdown Boards, a dedicated Class 1E Diesel Generator (DG) supplies power to essential safety systems on its respective 6.9 kV Shutdown Board.
3.2 Proposed Plant Modifications to the SON Electrical Distribution System The licensee plans to install GCBs and new USSTs with automatic load tap changers (LTCs).
These modifications would allow an offsite power configuration in which the USSTs are capable of supplying the normal power, with automatic transfer to the alternate power supply provided by a CSST. GCBs would be installed in the isolated phase bus (IPB) between the main generator
-4 and main bank transformers. Following plant modifications, both units can be powered from either the 500 kV grid or the 161 kV grid.
Specifically, after implementation of the USST modifications on both units, each new USST would be aligned as the normal power supply to only one 6.9 kV Shutdown Board via the associated Unit Board. Train-A Shutdown Boards (1A-A and 2A-A) would receive their normal power from USST 1A and USST 2A respectively. Train-B Shutdown Boards (1 B-B and 2B-B) would receive their normal power from USST 1Band USST 2B, respectively. The design function of each USST is to provide unit power to its respective 6.9 kV Unit Boards and Class 1E 6.9 kV Shutdown Board.
The new USSTs have higher impedance to limit fault current to below the 6.9 kV Unit Board circuit breaker rating. The USSTs have adequate capacity to support normal and accident loads. To support the offsite power requirements and improve normal operations, the USSTs are provided with automatic LTCs. The USST LTCs are similar to those installed on the current CSSTs.
Power circuit breakers (PCBs) are located between the high side of the main bank transformers and the switchyard. On a trip of the PCBs, offsite power would automatically transfer to the alternate power supply from a CSST. Upon receipt of a PCB trip signal, the transfer occurs by opening the Unit Board normal supply breaker and closing the alternate supply breaker. The alternate supply breaker would not close until the normal supply breaker opens. This transfer typically occurs within six cycles. PCBs would trip open on a fault between the GCBs and the PCBs, or a failure of the GCBs to open on a valid command signal.
During the time period between the SON, Unit 2 USST modification implementation and the SON, Unit 1 USST modification implementation, the output of USST 2A will be used as the normal power supply to 6.9 kV Shutdown Board 2A-A via Unit Board 2B, and the output of USST 2B will be used as the normal power supply to 6.9 kV Shutdown Board 2B-B via Unit Board 2C. CSST C will provide an alternate source of power for 6.9 kV Shutdown Board 2A-A via Unit Board 2B.
CSST A will provide an alternate source of power for 6.9 kV Shutdown-Board 2B-B via Unit Board 2C. Power to 6.9 kV Shutdown Board 1A-A will continue to be supplied by CSST C via Start Bus 1B and Unit Board 1B. Power to 6.9 kV Shutdown Board 1B-B will continue to be supplied by CSST A via Start Bus 1A and Unit Board 1C. This lineup essentially requires three power sources (USST 2A12B, CSST A, and CSST C) to supply the normal and alternate offsite power circuits. Alternatively, the CSSTs can provide the two immediate access offsite circuits with no required transfer, consistent with the current licensing basis.
After the SON, Unit 1 USST modification has been implemented, the normal offsite power alignment will be power supplied by the USSTs to the 6.9 kV Shutdown Boards via the 6.9 kV Unit Boards. Alternatively, power can be provided by one or more CSSTs via automatic transfer at the 6.9 kV Unit Boards on a trip of the PCBs. Other alignment configurations using other combinations of available USSTs and CSSTs will also be possible, as long as the alignments are consistent with the analyzed configurations, and comply with the requirements of GDC-17.
3.3 NRC Staff's Evaluation The NRC staff reviewed the proposed change to the SON TS and the licensee's justification for the change. The licensee states that the change is necessary as a result of the planned modifications to the plant design and operating configuration. As described above, the plant modifications would install new USSTs and GCBs in the IPB between the generator and main
-5 bank transformer. Under the new configuration, normal power will be supplied by the main generator through the USSTs and will allow use of the USSTs as an offsite power supply to the Class 'I E buses upon trip of the main generator. To determine the impact of plant modification on the SON electrical system, the NRC staff requested the licensee to provide a summary of the analysis performed to show that the voltage requirements to the plant safety system buses and components remain valid by the proposed modifications. In its response dated August 23,2012, the licensee confirmed that adequate voltage exists to start and accelerate all required loads consistent with the SON design basis requirements. Based on the response, the NRC staff determined that offsite power source would be acceptable when USSTs are being used to supply the unit boards.
The NRC staff requested a summary of the transmission system study, including grid stability analysis, to determine if the SON offsite power systems (161 kV and 500 kV) would be adequate to meet GDC-17 requirements after the plant modifications. In its response dated August 23,2012, the licensee stated the load flow study showed that the transmission system minimum bus voltage acceptance criteria were met for both the normal operating conditions and loss-of-coolant accident conditions, and the bus voltage was sufficiently maintained to meet GDC-17 requirements. In addition, the transient stability study showed that there were no changes to the transmission system voltage recovery characteristics that would result in instability of the normally cleared faults or adversely affect operation of the SON in-plant undervoltage relays or DG system. The fault study analysis was also performed using various operating configurations and scenarios. The short circuit current ratings of the plant auxiliary electrical system breakers and buses would be adequate to support the proposed USST modifications. Based on the response, the NRC staff determined that the two offsite power sources from 161 kV and 500 kV systems for SON would remain in compliance with GDC-17.
In the license amendment request (LAR), the licensee stated that the design function of each USST will be to provide unit power to its respective 6.9 kV Unit Boards and Class 1E 6.9 kV Shutdown Board. These new transformers would have a higher impedance to limit fault currents below the rating of the associated 6.9 kV Unit Board circuit breaker. The USST ratings would ensure adequate capacity for normal and accident loads and would include automatic LTCs to provide adequate 6.9 kV voltage regulation. The USST LTCs would be similar to those installed on the CSSTs and would have equivalent operating times. In its response to the NRC staff's questions regarding the failure modes of LTCs and capacity of the USSTs to support worst case design basis events, accidents, and abnormal operating occurrences, the licensee confirmed (1) the capacity of USSTs during transient accident loading and steady state accident loading, and (2) the capacity of USSTs for normal, anticipated operational occurrence, and accident loads is acceptable. The LTC failure modes were evaluated and no unacceptable conditions were identified. The periodic testing of the LTC controller would ensure that the device provides an acceptable response for the specified input. If the USST LTC fails before or during an accident, the associated 6.9 kV Shutdown Board would transfer to its dedicated DG when the board voltage reaches the degraded voltage relaying setpoint. High and low voltages are annunciated in the main control room (MCR). Based on this, the NRC staff determined that SON electrical system would remain in compliance with GDC-17.
The NRC staff requested a detailed summary of the evaluation that shows the new GCB performance tests, ratings and its capabilities are verified consistent with the guidance provided in the Institute of Electrical and Electronics Engineers Standard (IEEE Std) C37.013-1997, "IEEE -6 Standard for AC High-Voltage Generator Circuit Breakers Rated on a Symmetrical Current Basis,"
and NUREG-0800, Section 8.2, Appendix A, "Guidelines for Generator Circuit Breakers/Load Break Switches." In its response dated August 23,2012, the licensee provided a description of design tests performed by the GCB supplier and summary of the results. The tests discussed are rated dielectric strength, load current switching, short circuit current rating, rated transient recovery voltage, short-time current-carrying capability, duty cycle capability, rated continuous current-carrying test, mechanical endurance life test, rated interrupting time, and short circuit current with delayed current zero. Based on the above, the NRC staff finds that the proposed GCBs have the capability of interrupting the system maximum available fault current and qualify as an immediate access offsite power circuit in accordance with GDC-17 and meet the guidance provided in IEEE Std C37.013 and NUREG-0800, Section 8.2, Appendix A.
The NRC staff requested a summary of the bus transfer study, including a single failure of the bus transfer scheme or a worst-case failure of components in the plant auxiliary system. Based on the information provided by the licensee, the NRC staff finds that the guidance for bus transfers in American National Standards Institute C50.41 "Polyphase Induction Motors for Power Generating Stations" was used by the licensee and that the safety buses and loads would not be adversely affected by the transfer.
The NRC staff also requested information regarding the impact on short circuit current ratings of the plant auxiliary electrical system buses and breakers as a result of the proposed modification.
In its response, the licensee provided information to show that the short circuit ratings of medium voltage breakers and the switchgears would remain adequate to support the installation of the new USSTs.
Based on the above, the NRC staff concludes that SON continues to meet the requirements specified in GDC-17. Implementation of the USST modifications and installation of GCBs will enable use of a USST as the normal power supply to a 6.9 kV Unit Board, with an automatic transfer to the alternate power supply from a CSST on a trip of the PCBs. Either the USSTs or a CSST will be available in a few seconds to support safe shutdown of both units in the event of a loss of all onsite power and the loss of the other offsite circuit.
3.4 Changes to the SON Technical Specifications TS SR 4.8.1.1.1.a requires each of the above required independent circuits between the offsite transmission network and the onsite Class 1 E distribution system to be determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability.
The licensee proposed changes to the SON TS 3/4.8.1 to include an SR to demonstrate the required offsite circuits operable at least once per 18 months by manually and automatically transferring the power supply of a 6.9 kV Unit Board from the normal supply to the alternate supply.
Specifically, TS SR 4.8.1.1.1.b would be revised as follows with two notes.
TS SR 4.8.1.1.1.b would state:
Demonstrated OPERABLE at least once per 18 months by manually and automatically transferring the power supply to each 6.9 kV Unit Board from the normal supply to the alternate supply.
-7 The first note would preclude performance of the SR on the associated unit's 6.9 kV Unit Boards in MODES 1 and 2.
For Unit 1, this note would state:
For the 1A, 1B, 1C, and 1D 6.9 kV Unit Boards, this Surveillance shall not be performed in MODES 1 and 2.
For Unit 2, this note would state:
For the 2A, 2B, 2C, and 2D 6.9 kV Unit Boards, this Surveillance shall not be performed in MODES 1 and 2.
The second note would specify that verification of transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies.
For Units 1 and 2, this note would state:
Transfer capability is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies.
As stated in the licensee's submittal, the purpose of SR 4.8.1.1.1.b is to ensure that the power feeds, including those to the shutdown boards, would be transferred to a qualified offsite power circuit in accordance with GDC-17. The NRC staff reviewed the above additional SR 4.8.1.1.1.b requirement and the LAR and noted that following plant modifications, offsite power will normally be supplied from the USSTs to the 6.9 kV Unit Boards, and will automatically transfer to the alternate power supply to at least one circuit from the CSSTs on a trip of the PCBs. The transfer occurs when the Unit Board normal supply breaker opens and the alternate supply breaker closes.
The alternate supply breaker will not close until the normal supply breaker opens. Implementation of these design changes requires the licensee to demonstrate the capability to transfer the power supply to a 6.9 kV Unit Board from the normal supply to the alternate supply. The proposed addition of TS SR 4.8.1.1.1.b requirement to demonstrate that the required offsite circuits are OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 kV Unit Board from the normal supply to the alternate supply meets the requirements specified in 10 CFR 50.36(c) and GDC-18.
The NRC staff reviewed the two notes added to this SR as discussed above. The LAR states that this surveillance is only performed on 6.9 kV Unit Boards associated with the unit not in MODE 1 or 2. Restricting performance of the SR to MODE 3, 4, 5 or 6 will minimize the potential for inducing an electrical distribution subsystem perturbation that could result in a unit trip or actuation of an engineered safety feature (ESF) system. Perturbations to the electrical distribution subsystems are further minimized during performance of the SR on a 6.9 kV Unit Board by transferring the associated 6.9 kV Shutdown Board to the alternate feed (another 6.9 kV Unit Board that is not being tested) prior to performing the SR. Since the 6.9 kV Unit Board surveillance is performed on an unloaded board, it will not initiate a perturbation in an electrical distribution system that could challenge a plant safety related system, or challenge steady state conditions to the unit in operation. If the alignment of the associated 6.9 kV Shutdown Board to the alternate feed results in an inoperable offsite circuit, the Actions of LCO 3.8.1.1 will be entered
-8 and the provisions of LCO 3.0.5 will be invoked. By invoking LCO 3.0.5, the affected safety related equipment may be considered operable for the purpose of satisfying their applicable LCOs.
The licensee states that prior to performance of the SR, safety related equipment redundant to the equipment powered from the affected 6.9 kV Shutdown Board will be verified operable, as required by LCO 3.0.5. Failure of this surveillance will not challenge or cause an operational transient or challenge to plant safety systems for the unit in operation. The ability of the 6.9 kV Shutdown Board to transfer to the DG will not be inhibited should the ability of the associated 6.9 kV Unit Board to automatically or manually transfer to the alternate supply breaker not be functional. The LOOP circuits will still automatically strip the board and allow the diesel starting and loading sequence to occur providing power to the ESF systems as designed. The NRC staff noted that when the surveillance is being performed on the 6.9 kV Unit Board, its associated Shutdown Board loads will be transferred to another Unit Board that is not being tested prior to performing the surveillance, therefore the test has no impact on plant equipment.
Based on the above, the NRC staff determined that restricting performance of the SR to MODE 3, 4, 5 or 6 will minimize the potential for inducing an electrical distribution subsystem perturbation and is consistent with guidance provided in NUREG-1431, "Standard Technical Specifications Westinghouse Plants," as introduced in NRC approved Technical Specification Task Force (TSTF) change TSTF-283, Revision 3.
The second note specifies that automatic transfer from the normal supply to the alternate supply is only required to be met for 6.9 kV Unit Boards that require normal and alternate power supplies.
The NRC staff reviewed this note and determined that the note is clarifying the intent of the SR and is acceptable.
The requirements for offsite AC power sources are specified in SQN TS 3/4.8.1, "AC Sources, Operating." LCO 3.8.1.1.a requires two physically independent circuits between the offsite transmission network and the onsite Class 1E distribution system to be OPERABLE in MODES 1, 2,3, and 4. The NRC staff expressed concerns regarding the intermediate phase of the modifications (the time period between completion of the modifications in Unit 2 and the completion of modifications in Unit 1). Specifically, the NRC staff asked the licensee to clarify which independent power sources are required to be OPERABLE to meet the TS 3/4.8.1 requirement (two physically independent circuits between the offsite transmission network and the onsite Class 1E distribution system) until the Unit 1 USST modifications are completed. In its response dated August 23, 2012, the licensee modified TS 3/4.8.1, AC Sources, 3.8.1.1.a by adding a note that specifies:
Offsite circuits utilizing USST 2A and USST 2B as the normal power sources require CSST A and CSST C to be available as the alternate power sources via automatic transfer at the associated 6.9 kV Unit Boards. (CSST B can be substituted for CSST A or CSST C).
This Note remains in effect until November 30, 2013, or until the USST modifications are implemented on Units 1 and 2, whichever occurs first.
The NRC staff found adding the note to TS LCO 3.8.1.1.a is an acceptable method to clarify the circuits that are required to be OPERABLE per the LCO until the modifications are fully implemented at both units.
Other changes proposed in the TSs are administrative in nature and does not require the NRC
- 9 staff's review.
3.5 Description of Operator Actiones) and Assessed Safetv Significance The operator action supporting this proposed TS revision is the manual transfer of the power supply to a 6.9 kV Unit Board from the normal supply to the alternate supply. This action is done in the mild environment of the MCR. This is a backup action to an automatic transfer system. The cue for the initiation of the action is annunciation of trouble in the automatic transfer system, or by monitoring available electrical distribution instrumentation. Controls are available both in the MCR and at the local control stations. This action is not credited in any design-basis accident (DBA) and is not time-critical. The original design of SQN included a surveillance almost identical to the one being proposed in this LAR.
In accordance with the generic risk categories established in Appendix A to NUREG-1764, this task sequence is considered "low or no risk" due to the fact that it is not credited in any DBA.
However, because of its association with the loss of off-site power, the NRC staff performed a general human factors review (Le., the least stringent of the levels of graded review possible under the guidance of NUREG-1764).
3.6 Analysis The licensee has done an impact analysis on the plant modification supporting this LAR using TVA procedure NPG-SPP-09.3.1, "Guidelines for Preparation of Design Inputs and Change Impact Screen." The NRC staff finds that because the licensee's analysis was performed using a controlled administrative process, and because the results (see below) are reasonable, the analysis performed is acceptable for a low risk operator action such as that proposed in this LAR.
3.7 Design of Human-System Interfaces, Procedures. and Training 3.7.1 Human-System Interfaces Various new controls, displays, and annunciators will be added to the MCR and local control stations. No change to the safety parameter display system was needed.
3.7.2 Procedures The licensee reviewed annunciator response procedures, general operating procedures, system operating procedures, abnormal operating procedures, emergency operating procedures, surveillance instructions, technical instructions, and periodic instructions. Among those reviewed, many procedures were identified as requiring development or revision to reflect the pending modification. For example, abnormal operating procedure (AOP) AOP-P.01, "Loss of Offsite Power," has been identified for revision to address restoration of offsite power. Similar review efforts are planned for the maintenance procedures.
3.7.3 Training The TVA administrative processes require that training needs assessment be performed on new and revised procedures. Because procedure changes are being made for the TS revision and
-10 plant modification, they are required to be evaluated for potential training needs of licensed operators, nonlicensed operators, and maintenance personnel. Training material will be developed and presented for any identified training needs. It is anticipated that the new TS changes and procedure changes will require approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> of classroom training. In addition, the licensee stated that walk-down(s) of new equipment may be conducted to support the training and procedure changes. Task performance evaluations may also be required on the new tasks for non-licensed operators. The licensee anticipates that the additional training will be given to job incumbents and incorporated into the initial operator training.
The licensee also anticipates that a remote function will be added to the simulator model to emulate the new Unit 2 configuration for GCB trips and interlocks, as well as use of the USSTs as an electrical power source. Because the simulator is based on Unit 1, the licensee plans to modify the simulator to reflect the changes being made to the Unit 1 control room, in conjunction with the Unit 1 USSTlGCB modification.
3.7.4 Human Action Verification Because the USSTlGCB plant modification will result in a revision to AOP-P.01, and possibly emergency operating procedures (EOPs), the governing processes at SON require the procedures to be verified and validated. Per the controlling procedures, revised procedures may be walked down, as needed, to verify accuracy and usability.
3.8 Summary The proposed LAR was evaluated by the NRC staff to determine whether applicable regulations and requirements continue to be met. It was determined that the proposed changes do not require any exemptions or relief from regulatory requirements. Applicable regulatory requirements will continue to be met, adequate defense-in-depth will be maintained, and sufficient safety margins will be maintained. The NRC staff concludes that the proposed changes will not impact the licensee's compliance to the regulatory requirements of 10 CFR 50.36(c) and GOCs 17 and 18.
Therefore, the proposed changes are acceptable.
Based on the licensee's impact analysis done for the GCB/USST plant modification, the NRC staff finds that the planned revisions to procedures, training, and the human-system interface design supporting the proposed TS change, and the planned AOP and EOP verification and validation will provide a high level of confidence that SON operators will be able to reliably perform the manual actions proposed in this LAR. Therefore, the NRC staff finds this LAR acceptable from the human performance perspective.
The licensee included in its application, the revised TS Bases to be implemented with the TS changes. The NRC staff finds that the TS Bases Control Program is the appropriate process for updating the affected TS Bases pages and has, therefore, not included the affected Bases pages with these amendments.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendment. The State official had no comments.
- 11
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 and change surveillance requirements. 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 (77 FR 43379, July 24, 2012). 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 these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: R. Mathew A Matos-Marin G. Lapinsky Date: October 31,2012
October 31,2012 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 -ISSUANCE OF AMENDMENTS TO REVISE THE TECHNICAL SPECIFICATIONS 3/4.8.1 IN SUPPORT OF UNIT STATION SERVICE TRANSFORMER MODIFICATION (TS- SQN-12-01)
(TAC NOS. ME8772 AND ME8773)
Dear Mr. Shea:
The Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment No. 332 to Facility Operating License No. DPR-77 and Amendment No. 325 to Facility Operating License No. DPR-79 for the Sequoyah Nuclear Plant, Units 1 and 2, respectively. These amendments are in response to your application dated May 23, 2012, as supplemented by letter dated August 23,2012. The amendments request changes to Technical Specification 3/4.8.1 to include a surveillance requirement to demonstrate the required offsite circuits OPERABLE at least once per 18 months by manually and automatically transferring the power supply to a 6.9 KiloVolt Unit Board from the normal supply to the alternate supply. This change is necessary as a result of the planned modifications to the plant design and operating configuration that would install generator circuit breakers and new unit station service transformers to allow their use as an offsite power supply.
A copy of the Safety Evaluation is also enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice.
Sincerely, IRA!
Siva P. Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328
Enclosures:
- 1. Amendment No. 332 to DPR-77
- 2. Amendment No. 325 to DPR-79
- 3. Safety Evaluation cc w/enclosures: Distribution via Listserv Distribution:
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