CNL-23-045, License Amendment Request to Revise Technical Specification Table 1.1-1 Regarding the Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Bolts (WBN-TS-23-010)
| ML23219A011 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 08/07/2023 |
| From: | Hulvey K Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| CNL-23-045 | |
| Download: ML23219A011 (1) | |
Text
1101 Market Street, Chattanooga, Tennessee 37402 CNL-23-045 August 7, 2023 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 0001 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating Licenses Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391
Subject:
Watts Bar Nuclear Plant, Units 1 and 2 - License Amendment Request to Revise Technical Specification Table 1.1-1 Regarding the Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Bolts (WBN-TS-23-010)
References:
- 1. TVA letter to NRC, CNL-23-043, Watts Bar Nuclear Plant, Unit 1 -
Emergency License Amendment Request to Relax the Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Studs in Technical Specification Table 1.1-1, MODES (WBN-TS-23-09), dated May 4, 2023 (ML23124A403 and ML23124A404)
- 2. NRC letter to TVA, Watts Bar Nuclear Plant, Unit 1 - Issuance of Amendment No. 161 Regarding a One-Time Use Change to Footnotes Applicable to Technical Specification Table 1.1-1 Modes (Emergency Circumstances) (EPID L-2023-LLA-0064), dated May 5, 2023 (ML23125A220)
- 3. TVA letter to NRC, CNL-23-044, Transmittal of Revision 3 to WCAP-18774-P and WCAP-18774-NP, Addendum to the Rotterdam Dockyard Company Final Stress Report for 173" P.W.R. Vessels TVA III
& IV (Report No. 30749-B-030, Rev. 3) - Evaluation of One Closure Stud Out of Service for 40 Years for Watts Bar Units 1 and 2, (EPID L-2023-LLA-0064), dated June 1, 2023 (ML23152A150 and ML23152A151)
In Reference 1, Tennessee Valley Authority (TVA) submitted a request for a one-time emergency license amendment request (LAR) to Facility Operating License No. NPF-90 for the Watts Bar Nuclear Plant (WBN), Unit 1, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.91(a)(5). Reference 1 proposed a temporary change to WBN Unit 1 Technical Specification (TS) Table 1.1-1, MODES, footnotes (b) and (c), to allow completion of the WBN Unit 1 Cycle 18 refueling outage (U1R18) and transition to WBN
U.S. Nuclear Regulatory Commission CNL-23-045 Page 2 August 7, 2023 Unit 1 Cycle 19 operation and the subsequent Unit 1R19 with the required reactor pressure vessel head closure bolts fully tensioned. The required number of head closure bolts is at least 53 of 54 bolts. Reference 1 was approved by the Nuclear Regulatory Commission (NRC) in Reference 2.
In support of the technical evaluation of the WBN Unit 1 emergency LAR, Enclosure 2 to Reference 1 contained Westinghouse Electric Company LLC (Westinghouse)
WCAP-18774-P, Revision 1, Addendum to the Rotterdam Dockyard Company Final Stress Report for 173 P.W.R. Vessels TVA III & IV (Report No. 30749-B-030, Rev. 3) - Evaluation of One Closure Stud Out of Service for 40 Years for Watts Bar Units 1 and 2. As noted in Reference 1, due to the emergent nature of Reference 1, Enclosure 2 to Reference 1 was submitted as a proprietary document in its entirety. Therefore, in Reference 3, TVA submitted to the NRC a revision of WCAP-18774-P (i.e., WCAP-18774-P, Revision 3) with revised proprietary markings and an associated non-proprietary version.
WCAP-18774-P, Revision 3, supports continued operation of WBN Units 1 and 2 with at least 53 of 54 reactor pressure vessel head closure bolts fully tensioned. Therefore, in accordance with the provisions of 10 CFR 50.90, Application for amendment of license, construction permit, or early site permit, TVA is submitting a request for an amendment to Facility Operating License Nos. NPF-90 and NPF-96 for WBN Units 1 and 2, respectively to permanently revise WBN Units 1 and 2 TS Table 1.1-1, footnotes (b) and (c) to allow continued operation of WBN Units 1 and 2 with at least 53 of 54 reactor pressure vessel head closure bolts fully tensioned.
The enclosure to this submittal provides a description and assessment of the proposed change, a regulatory evaluation, and a discussion of environmental considerations. to the enclosure provides the existing WBN Unit 1 TS page marked up to show the proposed change. Attachment 2 to the enclosure provides the existing WBN Unit 2 TS page marked up to show the proposed change. There are no associated TS Bases pages for this request.
TVA has determined that there are no significant hazards considerations associated with the proposed change and that the TS change qualifies for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9). In accordance with 10 CFR 50.91(b)(1), TVA is sending a copy of this letter and enclosure to the Tennessee State Department of Environment and Conservation.
TVA requests approval of the proposed license amendment within one year from the date of this submittal with implementation within 30 days of issuance of the amendment.
There are no new regulatory commitments contained in this letter. Please address any questions regarding this request to Stuart L. Rymer, Senior Manager, Fleet Licensing, at slrymer@tva.gov.
U.S. Nuclear Regulatory Commission CNL-23-045 Page 3 August 7, 2023 I declare under penalty of perjury that the foregoing is true and correct. Executed on this 7th day of August 2023.
Respectfully, Kimberly D. Hulvey Director, Nuclear Regulatory Affairs
Enclosure:
Evaluation of the Proposed Change cc (Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant NRC Project Manager - Watts Bar Nuclear Plant Director, Division of Radiological Health - Tennessee State Department of Environment and Conservation Digitally signed by Edmondson, Carla Date: 2023.08.07 07:20:30 -04'00'
CNL-23-045 Enclosure Evaluation of the Proposed Change
Subject:
Watts Bar Nuclear Plant, Units 1 and 2 - License Amendment Request to Revise Technical Specification Table 1.1-1 Regarding the Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Bolts (WBN-TS-23-010)
CONTENTS 1.0
SUMMARY
DESCRIPTION............................................................................................. 1 2.0 DETAILED DESCRIPTION.............................................................................................. 1 2.1 System Design and Operation..................................................................................... 1 2.2 Current Technical Specifications Requirements........................................................... 1 2.3 Reason for the Proposed Change................................................................................ 2 2.4 Description of the Proposed Change............................................................................ 3
3.0 TECHNICAL EVALUATION
............................................................................................. 4
4.0 REGULATORY EVALUATION
........................................................................................ 4 4.1 Applicable Regulatory Requirements and Criteria........................................................ 4 4.2 Precedent.................................................................................................................... 5 4.3 No Significant Hazards Consideration.......................................................................... 6 4.4 Conclusion................................................................................................................... 7
5.0 ENVIRONMENTAL CONSIDERATION
........................................................................... 7
6.0 REFERENCES
................................................................................................................ 8 Attachments:
- 1. Proposed TS Change (Markup) for WBN Unit 1
- 2. Proposed TS Change (Markup) for WBN Unit 2
Enclosure CNL-23-045 E1 of 8 Evaluation of the Proposed Change 1.0
SUMMARY
DESCRIPTION In accordance with the provisions of Title 10 of the Code of Federal Regulations (10 CFR) 50.90, "Application for amendment of license, construction permit, or early site permit," Tennessee Valley Authority (TVA) is submitting a request for an amendment to Facility Operating License Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (WBN), Units 1 and 2, respectively to permanently revise WBN Units 1 and 2 Technical Specification (TS)
Table 1.1-1, MODES, footnotes (b) and (c) to allow continued operation of WBN Units 1 and 2 with at least 53 of 54 reactor pressure vessel head closure bolts fully tensioned. The basis for this proposed change is described in Section 2.3 to this enclosure.
2.0 DETAILED DESCRIPTION 2.1 System Design and Operation Section 2.1 to Reference 1 provides the system design and operation for the WBN Unit 1 reactor pressure vessel. The WBN Unit 2 reactor pressure vessel is similar to WBN Unit 1 and contains the same number of reactor pressure vessel head closure bolts.
2.2 Current Technical Specifications Requirements WBN Unit 1 TS Table 1.1-1 currently states:
Table 1.1-1 (page 1 of 1)
MODES MODE TITLE REACTIVITY CONDITION (keff)
% RATED THERMAL POWER (a)
AVERAGE REACTOR COOLANT TEMPERATURE
(°F) 1 Power Operation 0.99
> 5 NA 2
Startup 0.99
< 5 NA 3
Hot Standby
< 0.99 NA 350 4
Hot Shutdown (b)
< 0.99 NA 350 > Tavg > 200 5
Cold Shutdown (b)
< 0.99 NA
< 200 6
Refueling(c)
NA NA NA (a)
Excluding decay heat.
Enclosure CNL-23-045 E2 of 8 (b)
For transitioning from the Unit 1 Cycle 18 refueling outage, through Cycle 19, and prior to Cycle 20 operation, all required reactor vessel head closure bolts fully tensioned. The required number of head closure bolts is at least 53 of 54 bolts (stud 34 has been removed from service).
(c)
For transitioning from the Unit 1 Cycle 18 refueling outage, through Cycle 19, and prior to Cycle 20 operation, one or more required reactor vessel head closure bolts less than fully tensioned. The required number of head closure bolts is at least 53 of 54 bolts (stud 34 has been removed from service).
WBN Unit 2 TS Table 1.1-1 currently states:
Table 1.1-1 (page 1 of 1)
MODES MODE TITLE REACTIVITY CONDITION (keff)
% RATED THERMAL POWER (a)
AVERAGE REACTOR COOLANT TEMPERATURE
(°F) 1 Power Operation 0.99
> 5 NA 2
Startup 0.99
< 5 NA 3
Hot Standby
< 0.99 NA 350 4
Hot Shutdown (b)
< 0.99 NA 350 > Tavg > 200 5
Cold Shutdown (b)
< 0.99 NA
< 200 6
Refueling (c)
NA NA NA (a)
Excluding decay heat.
(b)
All reactor vessel head closure bolts fully tensioned.
(c)
One or more reactor vessel head closure bolts less than fully tensioned.
2.3 Reason for the Proposed Change In Reference 1, Tennessee Valley Authority (TVA) submitted a request for a one-time emergency license amendment request (LAR) for WBN Unit 1, which was approved by the Nuclear Regulatory Commission (NRC) in Reference 2. This emergency license amendment revised WBN Unit 1 TS Table 1.1-1, MODES, footnotes (b) and (c), to allow completion of the WBN Unit 1 Cycle 18 refueling outage (U1R18) and transition to WBN Unit 1 Cycle 19 operation and the subsequent Unit 1R19 with the required reactor pressure vessel head closure bolts fully tensioned. Specifically, the revised WBN Unit 1 TS Table 1.1-1, footnotes (b) and (c) stated that the required number of head closure bolts is at least 53 of 54 bolts (WBN Unit 1 stud 34 has
Enclosure CNL-23-045 E3 of 8 been removed from service). Reference 1 noted that the WBN Unit 1 stud 34 was removed from service during U1R16 in May 2020.
In support of the technical evaluation of the WBN Unit 1 emergency LAR, Enclosure 2 to Reference 1 contained Westinghouse Electric Company LLC (Westinghouse) WCAP-18774-P, Revision 1, Addendum to the Rotterdam Dockyard Company Final Stress Report for 173" P.W.R. Vessels TVA III & IV (Report No. 30749-B-030, Rev. 3) - Evaluation of One Closure Stud Out of Service for 40 Years for Watts Bar Units 1 and 2. As noted in Reference 1, due to the emergent nature of Reference 1, Enclosure 2 to Reference 1 was submitted as a proprietary document in its entirety. Therefore, in Reference 3, TVA submitted to the NRC, a revision of WCAP-18774-P (i.e., WCAP-18774-P, Revision 3) with revised proprietary markings and an associated non-proprietary version.
WCAP-18774-P, Revision 3, supports continued operation of WBN Units 1 and 2 with at least 53 of 54 reactor pressure vessel head closure bolts fully tensioned. Therefore, TVA is proposing to permanently revise WBN Units 1 and 2 TS Table 1.1-1, footnotes (b) and (c) to allow continued operation of WBN Units 1 and 2 with at least 53 of 54 reactor pressure vessel head closure bolts fully tensioned. The reference to WBN Unit 1 stud 34 being removed from service in WBN Unit 1 TS Table 1.1-1, footnotes (b) and (c) is also being removed to allow flexibility in the event that WBN Unit 1 stud 34 is returned to service.
2.4 Description of the Proposed Change WBN Unit 1 and 2 TS Tables 1.1-1 are being revised as follows:
Table 1.1-1 (page 1 of 1)
MODES MODE TITLE REACTIVITY CONDITION (keff)
% RATED THERMAL POWER (a)
AVERAGE REACTOR COOLANT TEMPERATURE
(°F) 1 Power Operation 0.99
> 5 NA 2
Startup 0.99
< 5 NA 3
Hot Standby
< 0.99 NA 350 4
Hot Shutdown (b)
< 0.99 NA 350 > Tavg > 200 5
Cold Shutdown (b)
< 0.99 NA
< 200 6
Refueling (c)
NA NA NA (a)
Excluding decay heat.
(b)
All required reactor vessel head closure bolts fully tensioned. The required number of head closure bolts is at least 53 of 54 bolts.
(c)
One or more required reactor vessel head closure bolts less than fully tensioned.
The phrase, The required number of head closure bolts is at least 53 of 54 bolts is being removed from Note (c) from WBN Unit 1 TS Table 1.1-1 because that statement does not directly apply to Note (c). Attachment 1 to this enclosure provides the existing WBN Unit 1 TS page marked up to show the proposed change. Attachment 2 to this enclosure provides the
Enclosure CNL-23-045 E4 of 8 existing WBN Unit 2 TS page marked up to show the proposed change. There are no associated TS Bases pages for this request.
3.0 TECHNICAL EVALUATION
The technical evaluation supporting this LAR is provided in Westinghouse Electric Company LLC (Westinghouse) WCAP-18774-P and WCAP-18774-NP (submitted to the NRC in References 1 and 3), which was evaluated by the NRC in Reference 2. WCAP-18774-P supports continued operation of WBN Units 1 and 2 with 53 of 54 reactor vessel head closure bolts fully tensioned. Section 5.1.4 of WCAP-18774-P specifically addresses thread engagement.
As noted in WCAP-18774-P, the maximum stresses in the adjacent studs, the bearing stress in the closure head flange, and the sealing of the reactor vessel O-rings remain acceptable when one stud is left out of service during reactor operation. All of the stress intensities still satisfy the applicable limits of Section III of the 1971 Edition of the ASME Code with Addenda through Winter 1971, which is the construction Code used to design the Watts Bar Unit 1 and Unit 2 reactor vessels. The cumulative usage factor (CUF) of less than 1.0 for the studs adjacent to the out-of-service stud permits the plant to operate for the remainder of the 40-year design life with one stud out of service to allow adequate time for contingencies regarding stud hole repair preparation and implementation.
Additionally, WBN has adopted code case (CC) N-864, which has been conditionally approved by the NRC in Regulatory Guide (RG) 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, Revision 20, which is incorporated by reference in 10 CFR 50.55a. The technical basis for CC N-864 is in EPRI Technical Report 3002007626, Nondestructive Evaluation: Reactor Pressure Vessel Threads in Flange Examination Requirements, March 2016 (ML16221A068).
The bounding preload calculated on page 6-6 of EPRI Technical Report 3002007626 (i.e.,
42,338 psi) is based on the largest PWR vessel ID of 173 inches and the smallest PWR stud diameter of 6 inches. The WBN reactor vessel design pressure (2,500 psi) and number of studs (54) are the same as the pressure and number of studs used in the EPRI preload calculation. The reactor vessels for WBN Units 1 and 2 also have the same vessel ID of 173 inches as used in the EPRI preload calculation. However, the WBN Units 1 and 2 stud diameter is larger at approximately 6.75 inches as compared to the stud diameter of 6 inches utilized in the denominator of the EPRI preload calculation. Utilizing the WBN Unit 1 and Unit 2 specific values in the preload calculation on page 6-6 of EPRI Technical Report 3002007626, the WBN preload is determined to be less than the EPRI bounding preload of 42,338 psi. In addition, the one stud out of service evaluation for WBN in WCAP-18774-P does not require a larger preload for boltup of the flanges in that condition. As a result, it is acceptable for WBN Unit 1 and Unit 2 to use Code Case N-864 even with one stud out of service.
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements and Criteria General Design Criteria WBN Units 1 and 2 were designed to meet the intent of the "Proposed General Design Criteria for Nuclear Power Plant Construction Permits" published in July 1967. The WBN construction permit was issued in January 1973. The WBN updated Final Safety Analysis Report (UFSAR),
Enclosure CNL-23-045 E5 of 8 however, addresses the General Design Criteria (GDC) published as Appendix A to 10 CFR 50 in July 1971. Conformance with the GDCs is described in Section 3.1.2 of the UFSAR.
Each criterion listed below is followed by a discussion of the design features and procedures that meet the intent of the criteria. Any exception to the 1971 GDC resulting from the earlier commitments is identified in the discussion of the corresponding criterion.
Criterion 14 - Reactor Coolant Pressure Boundary. The reactor coolant pressure boundary shall be designed, fabricated, erected, and tested so as to have an extremely low probability of abnormal leakage, or rapidly propagating failure, and of gross rupture.
Criterion 30 - Quality of reactor coolant pressure boundary. Components which are part of the reactor coolant pressure boundary shall be designed, fabricated, erected, and tested to the highest quality standards practical. Means shall be provided for detecting and, to the extent practical, identifying the location of the source of reactor coolant leakage.
Compliance with GDCs 14 and 30 are described in Section 3.1.2 of the WBN UFSAR.
With the implementation of the proposed changes, WBN Units 1 and 2 continue to meet the applicable regulations and requirements, subject to the previously approved exceptions.
4.2 Precedent The proposed changes are similar to the following NRC-approved license amendments.
In Reference 2, NRC approved an emergency LAR for WBN Unit 1, which revised WBN Unit 1 TS Table 1.1-1, footnotes (b) and (c), to allow completion of the WBN Unit 1 Cycle 18 refueling outage (U1R18) and transition to WBN Unit 1 Cycle 19 operation and the subsequent Unit 1R19 with the required reactor pressure vessel head closure bolts fully tensioned. Specifically, the revised WBN Unit 1 TS Table 1.1-1, footnotes (b) and (c) stated that the required number of head closure bolts is at least 53 of 54 bolts.
Braidwood Station Units 1 and 2 and Byron Station Units 1 and 2 on October 28, 2015, in Amendment Nos. 186 and 192, respectively (ML15232A441). These amendments approved the use of the methodology for developing the pressure and temperature limits reports and changed TS Table 1.1-1, MODES, footnote (b) to state: All required reactor vessel head closure bolts fully tensioned and footnote (c) to state: One or more required reactor vessel head closure bolts less than fully tensioned. The proposed license amendment request for WBN Units 1 and 2 is not requesting changes to the pressure and temperature limits methodology.
Callaway Plant Unit 1 on May 28, 1999, in Amendment No. 133 (ML021640446).
Amendment No. 133 converted the current TSs to the improved TSs. The amendment approved changes to TS Table 1.1-1 based on an NRC Safety Evaluation issued on May 26, 1988 (ML20155J379 and ML20155J490) associated with the operation of the Callaway Plant with stud #2 untensioned. Amendment No. 133 revised footnote (b) to state:
At least 53 of 54 reactor vessel head closure bolts fully tensioned, and footnote (c) to state:
Two or more reactor vessel head closure bolts less than fully tensioned.
The approved TS changes are similar to the changes proposed in this LAR.
Enclosure CNL-23-045 E6 of 8 4.3 No Significant Hazards Consideration Tennessee Valley Authority (TVA) is requesting a license amendment request (LAR) to Facility Operating License Nos. NPF-90 for Watts Bar Nuclear Plant (WBN) Unit 1 and NPF-96 for WBN Unit 2. This LAR permanently revises WBN Units 1 and 2 Technical Specification (TS)
Table 1.1-1, MODES, footnotes (b) and (c) to allow continued operation of WBN Units 1 and 2 with at least 53 of 54 reactor pressure vessel head closure bolts fully tensioned. Revision 3 to WCAP-18774-P and WCAP-18774-NP, Addendum to the Rotterdam Dockyard Company Final Stress Report for 173" P.W.R. Vessels TVA III & IV (Report No. 30749-B-030, Rev. 3) -
Evaluation of One Closure Stud Out of Service for 40 Years for Watts Bar Units 1 and 2, provides the technical evaluation in support of this proposed change.
TVA has evaluated whether or not a significant hazards consideration is involved with the proposed amendments by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment, as discussed below:
- 1. Does the proposed amendment involve a significant increase in the probability or consequence of an accident previously evaluated?
Response: No Overall protection system performance will remain within the bounds of the accident analyses. Because the stresses remain within American Society of Mechanical Engineers (ASME) Code allowables, the proposed change will not affect the probability of any event initiators. Nor will the proposed change affect the ability of any safety related equipment to perform its intended function. There will be no degradation in the performance of nor an increase in the number of challenges imposed on safety related equipment assumed to function during an accident situation.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No.
There are no changes in the method by which any safety related plant system performs its safety function. The method of plant operation is unaffected. Leakage would be precluded because adequate compression remains. Analysis demonstrates that any gap opening remains less than the springback recovery of the inner closure O-ring.
Because stresses remain within ASME Code allowables, no new accident scenarios, transient precursors, failure mechanisms, or limiting single failures are introduced as a result of this change.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
Enclosure CNL-23-045 E7 of 8
- 3. Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No.
The proposed change does not affect any safety limits or controlling numerical values for a parameter established in the updated final safety analysis report or any specific values that define margin that are established in the plants licensing basis. ASME Section III stress limits for affected components are not exceeded. Plant specific evaluations indicate that the reactor vessel will continue to meet ASME Code allowable stress criteria with the required reactor pressure vessel closure studs fully tensioned. The proposed change does not alter nor exceed the acceptance criteria for any analyzed event. There will be no effect on the manner in which safety limits or limiting safety system settings are determined nor will there be any effect on those plant systems necessary to assure the accomplishment of protection functions.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, TVA concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of no significant hazards consideration is justified.
4.4 Conclusion In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
5.0 ENVIRONMENTAL CONSIDERATION
A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.
Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
Enclosure CNL-23-045 E8 of 8
6.0 REFERENCES
- 1.
TVA letter to NRC, CNL-23-043, Watts Bar Nuclear Plant, Unit 1 - Emergency License Amendment Request to Relax the Required Number of Fully Tensioned Reactor Pressure Vessel Head Closure Studs in Technical Specification Table 1.1-1, MODES (WBN-TS-23-09), dated May 4, 2023 (ML23124A403 and ML23124A404)
- 2.
NRC letter to TVA, Watts Bar Nuclear Plant, Unit 1 - Issuance of Amendment No. 161 Regarding a One-Time Use Change to Footnotes Applicable to Technical Specification Table 1.1-1 Modes (Emergency Circumstances) (EPID L-2023-LLA-0064), dated May 5, 2023 (ML23125A220)
- 3.
TVA letter to NRC, CNL-23-044, Transmittal of Revision 3 to WCAP-18774-P and WCAP-18774-NP, Addendum to the Rotterdam Dockyard Company Final Stress Report for 173" P.W.R. Vessels TVA III & IV (Report No. 30749-B-030, Rev. 3) - Evaluation of One Closure Stud Out of Service for 40 Years for Watts Bar Units 1 and 2, (EPID L-2023-LLA-0064), dated June 1, 2023 (ML23152A150 and ML23152A151)
CNL-23-045 Enclosure Proposed TS Changes (Mark-Ups) for WBN Unit 1
Definitions 1.1 Watts Bar-Unit 1 1.1-7 Amendment 161, Table 1.1-1 (page 1 of 1)
MODES MODE TITLE REACTIVITY CONDITION (keff)
% RATED THERMAL POWER (a)
AVERAGE REACTOR COOLANT TEMPERATURE
(°F) 1 Power Operation 0.99
> 5 NA 2
Startup 0.99
< 5 NA 3
Hot Standby
< 0.99 NA 350 4
Hot Shutdown (b)
< 0.99 NA 350 > Tavg > 200 5
Cold Shutdown (b)
< 0.99 NA
< 200 6
Refueling (c)
NA NA NA (a)
Excluding decay heat.
(b)
For transitioning from the Unit 1 Cycle 18 refueling outage, through Cycle 19, and prior to Cycle 20 operation, aAll required reactor vessel head closure bolts fully tensioned.
The required number of head closure bolts is at least 53 of 54 bolts (stud 34 has been removed from service).
(c)
For transitioning from the Unit 1 Cycle 18 refueling outage, through Cycle 19, and prior to Cycle 20 operation, oOne or more required reactor vessel head closure bolts less than fully tensioned. The required number of head closure bolts is at least 53 of 54 bolts (stud 34 has been removed from service).
CNL-23-045 Enclosure Proposed TS Changes (Mark-Ups) for WBN Unit 2
Definitions 1.1 Watts Bar - Unit 2 1.1-8 Amendment Table 1.1-1 (page 1 of 1)
MODES MODE TITLE REACTIVITY CONDITION (keff)
% RATED THERMAL POWER (a)
AVERAGE REACTOR COOLANT TEMPERATURE
(°F) 1 Power Operation 0.99
> 5 NA 2
Startup 0.99
< 5 NA 3
Hot Standby
< 0.99 NA 350 4
Hot Shutdown (b)
< 0.99 NA 350 > Tavg > 200 5
Cold Shutdown (b)
< 0.99 NA
< 200 6
Refueling (c)
NA NA NA (a)
Excluding decay heat.
(b)
All required reactor vessel head closure bolts fully tensioned. The required number of head closure bolts is at least 53 of 54 bolts.
(c)
One or more required reactor vessel head closure bolts less than fully tensioned.