Text

Application to Modify Operating License Condition Regarding the Actions to Resolve Issues Identified in NRC Bulletin 2012-01, Design Vulnerability in Electrical Power System (391-WBN-TS-17-06)
	ML17093A608
Person / Time
Site:	Watts Bar
Issue date:	03/28/2017
From:	James Shea; Tennessee Valley Authority
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	391-WBN-TS-17-06, BL-12-001, CNL-17-027
	Download: ML17093A608 (14)
	v • d • e

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-17-027 March 28, 2017 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 2 Facility Operating License No. NPF-96 NRC Docket No. 50-391

Subject:

Application to Modify Operating License Condition for Watts Bar Nuclear Plant, Unit 2 Regarding the Actions to Resolve Issues Identified in NRC Bulletin 2012-01, Design Vulnerability in Electrical Power System (391-WBN-TS-17-06)

References:

1. NRC Bulletin 2012-01, Design Vulnerability in Electric Power System, dated July 27, 2012 (ML12074A115)

2. Letter from NEI to NRC, Industry Initiative on Open Phase Condition, dated October 9, 2013 (ML13333A147)

3. Letter from NEI to NRC, Industry Initiative on Open Phase Condition, Revision 1, dated March 16, 2015 (ML15075A455)

4. TVA letter to NRC, Response to Request for Additional Information Regarding Response to Bulletin 2012-01, Design Vulnerability In Electric Power System," dated February 3, 2014 (ML14038A075)

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," the Tennessee Valley Authority (TVA) is submitting a request for an amendment to Facility Operating License No. NPF-96 for the Watts Bar Nuclear Plant (WBN) Unit 2.

In Reference 1, the Nuclear Regulatory Commission (NRC) issued Bulletin 2012-01, "Design Vulnerability in Electric Power System," which required addressees to comprehensively verify compliance with the regulatory requirements of General Design Criterion (GDC) 17, Electric Power Systems, and the design criteria for protection systems under 10 CFR 50.55a(h)(2). In Reference 2, the Nuclear Energy Institute (NEI) notified the NRC that the nuclear industrys chief nuclear officers approved a formal initiative to address open phase condition (OPC). Reference 2 further stated that the initiative represented a

U.S. Nuclear Regulatory Commission CNL-17-027 Page 2 March 28, 2017 formal commitment among nuclear power plant licensees to address the OPC design vulnerability for operating reactors. Reference 2 provided a due date of December 31, 2017, to complete actions to resolve the OPC design vulnerability for this initiative. Subsequently, in Reference 3 this completion date was revised to December 31, 2018.

WBN Unit 2 Operating License (OL) Condition 2.C(5) requires:

By December 31, 2017, the licensee shall report to the NRC that the actions to resolve the issues identified in Bulletin 2012-01, Design Vulnerability in Electrical Power System, have been implemented.

Therefore, this license amendment proposes to revise the completion date for WBN Unit 2 OL Condition 2.C(5) from December 31, 2017 to December 31, 2018, to align with the remainder of the TVA fleet and with the nuclear industry.

TVA will continue to implement the interim compensatory measures as discussed in Reference 4 and inspected under NRC Inspection Manual Temporary Instruction (TI) 2515/192 Inspection of the Licensees Interim Compensatory Measures Associated with the Open Phase Condition Design Vulnerabilities in Electric Power Systems.

The enclosure to this letter provides a description of the proposed changes, technical evaluation of the proposed changes, regulatory evaluation, and a discussion of environmental considerations. Attachment 1 to the enclosure provides the existing OL page marked-up to show the proposed change. Attachment 2 to the enclosure provides the proposed OL page retyped to show the change incorporated.

The WBN Plant Operations Review Committee and the TVA Nuclear Safety Review Board have reviewed this proposed change and determined that operation of WBN Unit 2 in accordance with the proposed change will not endanger the health and safety of the public.

TVA has determined that there are no significant hazards considerations associated with the proposed change and that the license change qualifies for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9). Additionally, in accordance with 10 CFR 50.91(b)(1), TVA is sending a copy of this letter and enclosure to the Division of Radiological Health - Tennessee State Department of Environment and Conservation.

TVA requests approval of this proposed license amendment by December 1, 2017, with implementation within 15 days following the Nuclear Regulatory Commission approval.

There are no new regulatory commitments associated with this submittal. Please address any questions regarding this request to Edward Schrull at (423) 751-3850.

U.S. Nuclear Regulatory Commission CNL-17-027 Page 3 March 28, 2017 I declare under penalty of perjury that the foregoing is true and correct. Executed on this 28th day of March 2017.

J. W. Shea Vice President, Nuclear Licensing

Enclosure:

Evaluation of Proposed Change cc (Enclosure):

NRG Regional Administrator - Region II NRG Senior Resident Inspector - Watts Bar Nuclear Plant ,

NRG Project Manager - Watts Bar Nuclear Plant Director, Division of Radiological Health - Tennessee State Department of Environment and Conservation

ENCLOSURE Tennessee Valley Authority Watts Bar Nuclear Plant, Units 1 and Unit 2 391-WBN-TS-17-06 EVALUATION OF PROPOSED CHANGE

Subject:

Application to Modify Operating License Conditions for Watts Bar Nuclear Plant, Unit 2 Regarding the Actions to Resolve Issues Identified in NRC Bulletin 2012-01, Design Vulnerability in Electrical Power System, (391-WBN-TS-17-06)

CONTENTS 1.0 Summary Description ......................................................................................2 2.0 Detailed Description ........................................................................................2 3.0 Technical Evaluation .......................................................................................2 4.0 Regulatory Evaluation .....................................................................................3 4.1 Applicable Regulatory Requirements/Criteria .................................................. 3 4.2 Precedent ........................................................................................................4 4.3 Significant Hazards Consideration ................................................................... 5 4.4 Conclusions.....................................................................................................6 5.0 Environmental Consideration........................................................................... 6 6.0 References ......................................................................................................7 ATTACHMENTS

1. Proposed Operating License Change (Mark-Ups) for WBN Unit 2

2. Proposed Operating License Change (Final Typed) for WBN Unit 2 CNL-17-027 E-1 of 7

ENCLOSURE 1.0

SUMMARY

DESCRIPTION This evaluation supports a request to amend Facility Operating License (OL)

No. NPF-96 for the Tennessee Valley Authority (TVA) Watts Bar Nuclear Plant (WBN), Unit 2. The proposed change revises the completion date for OL Condition 2.C(5) regarding the reporting of actions taken to resolve issues identified in Nuclear Regulatory Commission (NRC) Bulletin 2012-01, Design Vulnerability in Electrical Power System. The proposed change revises the completion date in OL Condition 2.C(5) from December 31, 2017 to December 31, 2018, to align with the industry completion date in Reference 1 and the remainder of the TVA fleet.

2.0 DETAILED DESCRIPTION WBN Unit 2 OL Condition 2.C(5) currently states:

By December 31, 2017, the licensee shall report to the NRC that the actions to resolve the issues identified in Bulletin 2012-01, Design Vulnerability in Electrical Power System, have been implemented.

The proposed change revises WBN Unit 2 OL Condition 2.C(5) as follows:

By December 31, 2018, the licensee shall report to the NRC that the actions to resolve the issues identified in Bulletin 2012-01, Design Vulnerability in Electrical Power System, have been implemented.

3.0 TECHNICAL EVALUATION

On January 30, 2012, an operating event at Byron Station, Unit 2, revealed a significant design vulnerability where an open phase condition (OPC) in the plants offsite power supply caused a loss of certain safety functions powered by the sites alternating current (AC) electric power system. This event was documented in NRC Bulletin 2012-01 (Reference 2), which required addressees to comprehensively verify compliance with the regulatory requirements of General Design Criterion (GDC) 17, Electric Power Systems, and the design criteria for protection systems under Title 10 of the Code of Federal Regulations (10 CFR) Part 50.55a(h)(2).

TVA provided its response to NRC Bulletin 2012-01 for WBN Unit 2 in Enclosure 3 of Reference 3. Based on review of the response, NRC staff determined that the design vulnerability exists at WBN Unit 2 electric power system and no design features have been provided to enable functioning of electric power system with an OPC with offsite power circuits.

In Reference 4, the Nuclear Energy Institute (NEI) informed the NRC that the nuclear industry had formally approved an initiative to address the open phase condition in the off-site power circuits with a completion date of December 31, 2017.

Subsequently, in Reference 5, the NRC issued a request for additional information (RAI) requesting licensees to provide a schedule for completion of plant design changes and modifications to resolve the open phase design vulnerability. In Reference 6, TVA provided its response to the RAI and endorsed the generic schedule provided in the industry OPC initiative.

CNL-17-027 E-2 of 7

ENCLOSURE In Reference 7, TVA proposed a license condition for WBN Unit 2 associated with actions for resolving NRC Bulletin 2012-01 with a completion date of December 31, 2017. In Section 8.2.2 of Reference 8, the NRC concurred with this proposed license condition and stated:

Based on the above, the staff concludes that there is reasonable assurance that OPC design vulnerability with the WBN Unit 2 electric power system will be addressed by TVA when license conditions and regulatory commitments are met. The staff will close Bulletin 2012-01 for WBN Unit 2 when TVA notifies the NRC with a close-out letter when full compliance is achieved.

Subsequently, in Reference 9, the NRC issued the OL for WBN Unit 2 that contained OL Condition 2.C(5) with the completion date of December 31, 2017, regarding NRC Bulletin 2012-01.

In Reference 1, NEI informed the NRC that the original schedule to complete actions to resolve the OPC design vulnerability under this initiative was being revised from December 31, 2017 to December 31, 2018. Therefore, TVA proposes to revise the completion date for WBN Unit 2 OL Condition 2.C(5) from December 31, 2017 to December 31, 2018, to align with the remainder of the TVA fleet and with the nuclear industry.

TVA has concluded that the change in the completion date does not affect the basis of the NRC approval in Reference 8.

4.0 REGULATORY EVALUATION

4.1 APPLICABLE REGULATORY REQUIREMENTS/CRITERIA As noted in the WBN dual-unit updated final safety analysis report (UFSAR)

Section 3.1.1, WBN was 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 dual-unit UFSAR, however, addresses the NRC General Design Criteria (GDC) published as Appendix A to 10 CFR 50 in July 1971, including Criterion 4 as amended October 27, 1987.

The WBN UFSAR contains these GDC followed by a discussion of the design features and procedures that meet the intent of the criteria. The relevant GDC is described below.

Criterion 17 - Electric power systems An onsite electric power system and 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 (assuming the other system is not functioning) shall be to provide sufficient capacity and 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.

CNL-17-027 E-3 of 7

ENCLOSURE The onsite power sources, including the batteries, and the onsite electric distribution system, shall have sufficient independence, redundancy, and testability to perform their safety functions assuming a single failure.

Electric power from the transmission network to the onsite electric distribution system shall be supplied by two physically independent circuits (not necessarily on separate rights of way) 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. A switchyard common to both circuits is acceptable. Each of these circuits shall be designed to be available in sufficient time following a loss of all onsite alternating current power supplies and the other offsite electric power circuit, to assure that specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded. One of these circuits shall be designed to be available within a few seconds following a LOCA to assure that core cooling, containment integrity, and other vital safety functions are maintained.

Provisions shall be included to minimize the probability of losing electric power from any of the remaining sources as a result of, or coincident with, the loss of power generated by the nuclear power unit, the loss of power from the transmission network, or the loss of power from the onsite electric power sources.

Conformance with GDC 17 is described in Section 3.1.2.2 of the WBN dual-unit UFSAR.

There will be no changes to the WBN design such that compliance with any of the above regulatory requirements would come into question. As such, WBN Unit 2 will continue to comply with the applicable regulatory requirements.

4.2 PRECEDENT There are no other applicable regulatory precedents regarding the changes proposed in this license amendment request. As noted in Section 3.0. the proposed completion date is consistent with the date to resolve the OPC design vulnerability provided in Reference 1.

CNL-17-027 E-4 of 7

ENCLOSURE 4.3 SIGNIFICANT HAZARDS CONSIDERATION The Tennessee Valley Authority (TVA) proposes to revise the completion date for the Watts Bar Nuclear (WBN) Plant, Unit 2 Operating License (OL) Condition 2.C(5) regarding the reporting of actions taken to resolve issues identified in Nuclear Regulatory Commission (NRC) Bulletin 2012-01, Design Vulnerability in Electrical Power System. The proposed license amendment revises the completion date in OL Condition 2.C(5) from December 31, 2017 to December 31, 2018.

TVA has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) 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 consequences of an accident previously evaluated?

Response: No.

The proposed changes to revise the completion date for OL Condition 2.C(5) for WBN Unit 2 regarding the reporting of actions taken to resolve issues identified in NRC Bulletin 2012-01 from December 31, 2017 to December 31, 2018 do not affect the structures, systems, or components (SSCs) of the plant, affect plant operations, or any design function or any analysis that verifies the capability of an SSC to perform a design function. No change is being made to any of the previously evaluated accidents in the WBN Updated Final Safety Analysis Report (UFSAR).

The proposed changes do not 1) require physical changes to plant SSCs;

2) prevent the safety function of any safety-related system, structure, or component during a design basis event; 3) alter, degrade, or prevent action described or assumed in any accident described in the WBN UFSAR from being performed because the safety-related SSCs are not modified; 4) alter any assumptions previously made in evaluating radiological consequences; or

5) affect the integrity of any fission product barrier.

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.

The proposed changes do not introduce any new accident causal mechanisms, because no physical changes are being made to the plant, nor do they affect any plant systems that are potential accident initiators.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

CNL-17-027 E-5 of 7

ENCLOSURE

3. Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No.

The margin of safety associated with the acceptance criteria of any accident is unchanged. The proposed changes will have no effect on the availability, operability, or performance of safety-related systems and components. The proposed change will not adversely affect the operation of plant equipment or the function of equipment assumed in the accident analysis.

The proposed amendment does not involve changes to any safety analyses assumptions, safety limits, or limiting safety system settings. The changes do not adversely affect plant-operating margins or the reliability of equipment credited in the safety analyses.

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

S In conclusion, based on the considerations discussed above, there is reasonable assurance that (1) 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 Commissions 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.

CNL-17-027 E-6 of 7

ENCLOSURE

6.0 REFERENCES

1. Letter from NEI to NRC, Industry Initiative on Open Phase Condition, Revision 1, dated March 16, 2015 (ML15075A455)

2. NRC Bulletin 2012-01, Design Vulnerability in Electric Power System, dated July 27, 2012 (ML12074A115)

3. TVA letter to NRC, 90-Day Response to NRC Bulletin 2012-01, Design Vulnerability in Electric Power System, dated October 25, 2012 (ML12312A167)

4. Letter from NEI to NRC, Industry Initiative on Open Phase Condition, dated October 9, 2013 (ML13333A147)

5. NRC letter to various licensees, Request for Additional Information Regarding Response to Bulletin 2012-01, Design Vulnerability In Electric Power System," dated December 20, 2013 (ML13351A314)

6. TVA letter to NRC, Response to Request for Additional Information Regarding Response to Bulletin 2012-01, Design Vulnerability In Electric Power System," dated February 3, 2014 (ML14038A075)

7. TVA letter to NRC, Watts Bar Nuclear Plant Unit 2 - Response to NRC Requests Related to Granting an Operating License, dated September 3, 2014 (ML14247A231)

8. NUREG-0847, Supplement 27, "Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant, Unit 2," issued January 2015

9. NRC letter to TVA, Issuance of Facility Operating License No. NPF-96, Watts Bar Nuclear Plant Unit 2, dated October 22, 2015 (ML15251A587)

CNL-17-027 E-7 of 7

ENCLOSURE ATTACHMENT 1 Proposed Operating License Changes (Mark-Ups) for WBN Unit 2 CNL-17-027

C. The license shall be deemed to contain and is subject to the conditions specified in the Commissions 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 TVA is authorized to operate the facility at reactor core power levels not in excess of 3411 megawatts thermal.

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 2, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

(3) TVA shall implement permanent modifications to prevent overtopping of the embankments of the Fort Loudon Dam due to the Probable Maximum Flood by February 1, 2017.

(4) PAD4TCD may be used to establish core operating limits for Cycles 1 and 2 only. PAD4TCD may not be used to establish core operating limits for subsequent reload cores.

(5) By December 31, 20178, the licensee shall report to the NRC that the actions to resolve the issues identified in Bulletin 2012-01, Design Vulnerability in Electrical Power System, have been implemented.

(6) The licensee shall maintain in effect the provisions of the physical security plan, security personnel training and qualification plan, and safeguards contingency plan, and all amendments made pursuant to the authority of 10 CFR 50.90 and 50.54(p).

(7) TVA shall fully implement and maintain in effect all provisions of the Commission approved cyber security plan (CSP), including changes made pursuant to the authority of 10 CFR 50.90 and 10 CFR 50.54(p).

The TVA approved CSP was discussed in NUREG-0847, Supplement 28.

(8) TVA shall implement and maintain in effect all provisions of the approved fire protection program as described in the Fire Protection Report for the facility, as described in NUREG-0847, Supplement 29, subject to the following provision:

Unit 2 Amendment No. 5, XX Facility Operating License No. NPF-96

ENCLOSURE ATTACHMENT 2 Proposed Operating License Change (Final Typed) for WBN Unit 2 CNL-17-027

C. The license shall be deemed to contain and is subject to the conditions specified in the Commissions 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 TVA is authorized to operate the facility at reactor core power levels not in excess of 3411 megawatts thermal.

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 2, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

(3) TVA shall implement permanent modifications to prevent overtopping of the embankments of the Fort Loudon Dam due to the Probable Maximum Flood by February 1, 2017.

(4) PAD4TCD may be used to establish core operating limits for Cycles 1 and 2 only. PAD4TCD may not be used to establish core operating limits for subsequent reload cores.

(5) By December 31, 2018, the licensee shall report to the NRC that the actions to resolve the issues identified in Bulletin 2012-01, Design Vulnerability in Electrical Power System, have been implemented.