Text

License Amendment Request for Adoption of Technical Specification Task Force Traveler TSTF-276-A Revision 2, Change TS 3.8.1. AC Sources-Operating. to Clarify the Power Factor Requirements When Performing Diesel Gener
	ML23156A550
Person / Time
Site:	Perry
Issue date:	06/05/2023
From:	Penfield R; Energy Harbor Nuclear Corp
To:	; Office of Nuclear Reactor Regulation, Document Control Desk
References
	L-22-249, TSTF-276-A, Rev 2
	Download: ML23156A550 (1)
	v • d • e

.a energy Energy Harbor Nuclear Corp.

Perry Nuclear Power Plant

~ harbor 10 Center Road Perry, Ohio 44081 Rod L. Penfield 440-280-5382 Site Vice President, Perry Nuclear June 5, 2023 L-22-249 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Perry Nuclear Power Plant, Unit 1 Docket No. 50-440, License No. NPF-58 License Amendment Request for Adoption of Technical Specification Task Force Traveler TSTF-276-A. Revision 2. Change TS 3.8.1. AC Sources-Operating. to Clarify the Power Factor Requirements When Performing Diesel Generator Testing Pursuant to 10 CFR 50.90, the Energy Harbor Nuclear Corp. is submitting a request for amendment to the Perry Nuclear Power Plant, Unit 1 (PNPP) Technical Specification (TS) 3.8.1, AC Sources - Operating. The proposed change would modify the notes to TS Surveillance Requirements (SR) 3.8.1.9, diesel generator (DG) single largest load rejection test, 3.8.1.10, DG full load rejection test, and 3.8.1.14, DG endurance and margin test, to require that these SRs be performed at a specified power factor of s 0.9 with clarifications addressing situations when the power factor cannot be achieved. This change is consistent with NRG-approved NUREG-1434, Standard Technical Specifications, General Electric BWR/6 Plants, Revision 5, and NRG-approved TSTF-276-A, Revision 2 (TSTF-276).

An evaluation of the proposed change is enclosed with markup pages of the existing TS and TS Bases. This amendment application does not involve a significant hazard consideration as determined per 10 CFR 50.92, "Issuance of Amendment."

Approval of the proposed amendment is requested by June 28, 2024. Once approved, the amendment shall be implemented within 90 days.

There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Mr. Phil H. Lashley, Manager, Fleet Licensing, at (330) 696-7208.

Perry Nuclear Power Plant L-22-249 Page 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on June 5, 2023.

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Rod L. Penfield Attachments:

1 Evaluation of the Proposed Change 2 Technical Specification Page Markups 3 Technical Specification Pages Retyped 4 Technical Specification Bases Page Markups (for information only) cc: NRC Region Ill Administrator NRC Resident Inspector NRR Project Manager Executive Director, Ohio Emergency Management Agency, State of Ohio (NRC Liaison)

Utility Radiological Safety board

Attachment 1 L-22-249 Evaluation of the Proposed Change Page 1 of 9

Subject:

License Amendment Request to Adopt Technical Specification Task Force Traveler TSTF-276, Revision 2, Change TS 3.8.1, AC Sources-Operating, to Clarify the Power Factor Requirements When Performing Diesel Generator Testing 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION 2.1 System Design and Operation 2.2 Current Technical Specifications Requirements 2.3 Reason for the Proposed Change 2.4 Description of the Proposed Change

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration Analysis 4.3 Conclusions

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

L-22-249 Page 2 of 9 1.0

SUMMARY

DESCRIPTION Pursuant to 10 CFR 50.90, the Energy Harbor Nuclear Corp. is submitting a request for amendment to the Perry Nuclear Power Plant (PNPP) Technical Specification (TS) 3.8.1, AC Sources - Operating. The proposed change would modify TS Surveillance Requirements (SR) 3.8.1.9, diesel generator (DG) single largest load rejection test, 3.8.1.10, DG full load rejection test, and 3.8.1.14, DG endurance and margin test, to require that these SRs be performed at a specified power factor of 0.9 with clarifications addressing situations when the power factor cannot be achieved. This change is consistent with NRC-approved NUREG-1434, Standard Technical Specifications, General Electric BWR/6 Plants, Revision 5, and NRC-approved TSTF-276-A, Rev 2 (TSTF-276).

2.0 DETAILED DESCRIPTION 2.1 System Design and Operation The PNPP Class 1E AC Electrical Power Distribution System AC sources consist of the offsite power sources and the onsite standby power sources (Division 1, 2, and 3 diesel generators). As required by 10 CFR 50, Appendix A, GDC 17, the design of the AC electrical power system provides independence and redundancy to ensure an available source of power to the engineered safety feature (ESF) systems.

The Class 1E AC distribution system supplies electrical power to three divisional load groups, with each division powered by an independent Class 1E 4.16 kV ESF bus.

Each ESF bus receives power from the 345 kV grid through two separate independent circuits. Each ESF bus has a dedicated onsite DG. Ratings for DGs satisfy the requirements of Regulatory Guide 1.9. The DG continuous service rating is 7000 Kw for Divisions 1 and 2 and is 2600 Kw for Division 3, with 10% overload permissible for up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months in any 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period.

Offsite power is supplied to the switchyard from the transmission network. From the switchyard two electrically and physically separated circuits provide AC power to each 4.16 kV ESF bus. The offsite AC electrical power circuits are designed and located to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. The onsite standby power source for each 4.16 kV ESF bus is a dedicated DG.

Each DG must be capable of starting, accelerating to rated speed and voltage, and connecting to its respective ESF bus on detection of bus undervoltage. Each DG must also be capable of accepting required loads within the assumed loading sequence intervals and must continue to operate until offsite power can be restored to the ESF buses. These capabilities are required to be met from a variety of initial conditions such as DG in standby with engine hot and DG in standby with engine at ambient conditions.

Additional DG capabilities must be demonstrated to meet required surveillances, L-22-249 Page 3 of 9 including SR 3.8.1.9, DG single largest load rejection test, SR 3.8.1.10, DG full load rejection test, and SR 3.8.1.14, DG endurance and margin test.

Each DG is provided with an engine overspeed trip to prevent damage to the engine.

Recovery from the transient caused by the loss of a large load could cause diesel engine overspeed, which, if excessive, might result in a trip of the engine. SR 3.8.1.9 demonstrates the DG load response characteristics and capability to reject the largest single load while maintaining a specified margin to the overspeed trip. SR 3.8.1.10 demonstrates the DG capability to reject a full load, that is, maximum expected accident load, without overspeed tripping or exceeding the predetermined voltage limits. SR 3.8.1.14 verifies conformance with Regulatory Guide 1.108, paragraph 2.a.(3), which requires demonstration that the DGs can start and run continuously at full load capability for an interval of not less than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months - 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months of which is at a load equivalent to the continuous rating of the DG, and 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of which is at a load equivalent to 110% of the continuous duty rating of the DG.

These surveillances are performed with the DG synchronized with offsite power. When the DG is not synchronized with offsite power, the power factor is determined by plant load and cannot be adjusted.

2.2 Current Technical Specification Requirements PNPP TS 3.8.1, AC Sources - Operating, specifically SR 3.8.1.9, SR 3.8.1.10, and SR 3.8.1.14, state that when a DG is synchronized with offsite power for load rejection or endurance and margin testing, the SR shall be performed at a power factor of 0.9.

2.3 Reason for the Proposed Change The requirement in SRs 3.8.1.9, 3.8.1.10, and 3.8.1.14 is that DG testing shall be performed at a power factor of 0.9. The proposed change requires the DG to be tested under load conditions that are as close to design basis conditions as possible.

When a DG is synchronized with offsite power, a power factor of 0.9 is representative of the inductive loading the DG would experience under design basis accident conditions. However, under certain grid conditions, this power factor may not be achievable. Under such circumstances, the proposed change allows the surveillances to be performed at a power factor as close as practicable to 0.9. The change adds notes to address the power factor limits and is intended to improve clarity and ensure requirements are fully understood and consistently applied.

2.4 Description of the Proposed Change The following changes are proposed for PNNP TS 3.8.1 in accordance with TSTF-276:

SR 3.8.1.9 (DG single largest load rejection test) is revised by adding to Note 2: However, if grid conditions do not permit, the power factor limit is not L-22-249 Page 4 of 9 required to be met. Under this condition the power factor shall be maintained as close to the limit as practicable.

SR 3.8.1.10 (DG full load rejection test) is revised by removing operating at a power factor 0.9 from the surveillance, changing NOTE to NOTES, adding 1. to the existing note, and adding Note 2: If performed with DG synchronized with offsite power, it shall be performed at a power factor 0.9.

However, if grid conditions do not permit, the power factor limit is not required to be met. Under this condition the power factor shall be maintained as close to the limit as practicable.

SR 3.8.1.14 (endurance and margin test) is revised by removing from the surveillance operating at a power factor 0.9 and adding Note 3: If performed with DG synchronized with offsite power, it shall be performed at a power factor 0.9 for Division 1, 2, and 3 DGs. However, if grid conditions do not permit, the power factor limit is not required to be met. Under this condition the power factor shall be maintained as close to the limit as practicable.

Proposed revisions to TS Bases for SR 3.8.1.9, SR 3.8.1.10, and SR 3.8.1.14 are included in this application. The changes to TS Bases are consistent with TSTF-276, describing that DG testing performed when synchronized with offsite power shall be performed at a power factor 0.9, unless conditions do not allow this, in which case, the power factor shall be maintained as close to 0.9 as possible. The changes to the affected TS Bases pages will be incorporated in accordance with the TS Bases Control Program.

3.0 TECHNICAL EVALUATION

PNPP performs SR 3.8.1.9, SR 3.8.1.10, and SR 3.8.1.14 with the DG synchronized with offsite power. When the DG is synchronized with offsite power a power factor of 0.9 is representative of the inductive loading a DG would experience under design basis accident conditions. When the DG is not synchronized with offsite power, the power factor is determined by plant load and cannot be adjusted. Also, adequate load may not be available, or it could be difficult to achieve the loads required by the SR.

A power factor of 0.9 should normally be able to be achieved when performing this surveillance test at power and synchronized with offsite power. Therefore, a power factor of 0.9 is desired when performing these surveillances. However, under certain grid conditions, this power factor may not be achievable. When grid voltage is higher than typical, the additional field excitation current required to achieve a power factor 0.9 results in ESF bus voltage exceeding the maximum steady state voltage limit.

Increased grid voltage typically occurs when the plant is shutdown and the loads on the associated ESF transformer are too light to lower the voltage sufficiently to achieve a 0.9 power factor. Under these conditions, the power factor should be maintained as L-22-249 Page 5 of 9 close as practicable to a 0.9 power factor while still maintaining acceptable voltage limits on the ESF busses. In other circumstances, the grid voltage may be such that the DG excitation levels needed to obtain a power factor of 0.9 may not cause unacceptable voltages on the emergency busses, but the excitation levels are greater than those recommended for the DG. In such cases, the power factor shall be maintained as close as practicable to 0.9 without exceeding DG excitation limits.

The proposed changes to SR 3.8.1.9, SR 3.8.1.10, and SR 3.8.1.14 to require that they be performed at a power factor of 0.9, if performed with the DG synchronized to offsite power unless grid conditions do not permit, are consistent with NRC approved traveler TSTF-276-A, Revision 2. The proposed changes require the DG to be tested under load conditions that are as close to design basis conditions as possible. Under certain conditions, however, the proposed changes allow the surveillance to be conducted at a power factor other than 0.9.

There exists a slight potential for failure during performance of a surveillance test, but it would be limited to the DG that is being tested. Load test overload protection, when testing with the DG synchronized with the offsite power, is provided by a single unit solid state underfrequency relay. Should an offsite power anomaly occur that overloads the diesel generator during load testing, this relay acts to trip the Class 1E offsite source breakers while leaving the diesel generator connected to the bus. The alternate DG will remain operable and in a standby condition during the performance of the SR and would not be susceptible to a common grid disturbance and a common cause failure.

Furthermore, procedure precautions ensure that testing will not be performed under potentially adverse external plant conditions (such as storms, unstable grid conditions, and so forth).

These changes do not significantly affect the ability of these surveillances to verify that the DG is capable of performing its safety function. Therefore, the proposed changes still afford adequate assurance of safety when judged against current regulatory standards.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria

Section 182a of the Atomic Energy Act requires applicants for nuclear power plant operating licenses to include TSs as part of the operating license application. The TSs ensures the operational capability of structures, systems, and components that are required to protect the health and safety of the public. The U.S. Nuclear Regulatory Commission's (NRC's) requirements related to the content of the TSs are contained in Section 50.36 of the Title 10 of the Code of Federal Regulations (10 CFR 50.36), which requires that the TSs include items in the following specific categories: (1) safety limits, limiting safety system settings, and limiting control settings; (2) limiting conditions for L-22-249 Page 6 of 9 operation; (3) surveillance requirements per 10 CFR 50.36(c)(3); (4) design features; and (5) administrative controls.

The regulations in 10 CFR 50.36(c)(3) specify that SRs are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met.

General Design Criteria (GDC) 17, "Electric power systems," of 10 CFR 50, Appendix A, "General Design Criteria for Nuclear Power Plants," requires, in part, that 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 onsite electric power supplies, 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. In addition, this criterion requires provisions to minimize the probability of losing electric power from any of the remaining supplies 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 supplies.

GDC 18, "Inspection and Testing of Electric Power Systems," requires that electric power systems important to safety be designed to permit appropriate periodic inspection and testing to demonstrate operability and functional performance.

Regulatory Guide 1.9, (Safety Guide 9) August 10, 1971, Selection of Diesel Generator Set Capacity for Standby Power Supplies. This safety guide describes an acceptable basis for the selection of diesel generator sets of sufficient capacity and margin to implement General Design Criterion 17.

Application of the PNPP standby DGs complies with the recommendations of this regulatory guide.

Regulatory Guide 1.108, Rev 1, August 1977, Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants. This regulatory guide describes a method acceptable to the NRC staff for complying with the Commission's regulations with regard to periodic testing of diesel electric power units to ensure that the diesel electric power systems will meet their availability requirements. At PNPP, the guidelines presented in this regulatory guide are used in establishing preoperational and periodic test procedures for the standby (Division 1 and 2) and HPCS (Division 3) DGs.

The proposed changes to the SRs are consistent with TSTF-276 and ensures that the DG is tested under load conditions that are as close to design basis conditions as L-22-249 Page 7 of 9 possible. The design of the PNPP AC electrical power system provides independence and redundancy to ensure an available source of power to the engineered safety feature systems.

Based on this, the proposed changes do not affect compliance with these regulations or guidance and will ensure that the lowest functional capabilities or performance levels of equipment required for safe operation are met.

4.2 No Significant Hazards Consideration Pursuant to 10 CFR 50.90, the Energy Harbor Nuclear Corp. is submitting a request for amendment to the Perry Nuclear Power Plant Technical Specification 3.8.1, AC Sources - Operating. The proposed changes would modify the TS Surveillance Requirements 3.8.1.9, diesel generator (DG) single largest load rejection test, 3.8.1.10, DG full load rejection test, and 3.8.1.14, DG endurance and margin test, to require that these SRs be performed at a specified power factor of 0.9 with clarifications addressing situations when the power factor cannot be achieved. The proposed changes allow the surveillances to be performed at a power factor as close as practicable to 0.9 when the DG is synchronized with offsite power. The changes are consistent with NRC-approved NUREG-1434, Standard Technical Specifications, General Electric BWR/6 Plants, Revision 5, and NRC-approved TSTF-276-A, Rev 2.

Energy Harbor Nuclear Corp. 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.

Performing a surveillance that tests the DG is not a precursor of any accident previously evaluated. Relaxing the requirement to maintain a specific power factor limit when synchronized with offsite power does not significantly affect the method of performing the surveillances such that the probability of an accident would be affected. The changes only affect surveillances of mitigative equipment and, therefore, do not have an impact on the probability of an accident previously evaluated.

Revising the surveillances by relaxing the requirement to maintain a specific power factor limit when synchronized to offsite power does not affect performance of the DG under accident conditions. The performance of the surveillances ensures that mitigative equipment is capable of performing its intended function, and therefore, the changes do not involve a significant increase in the consequences of an accident previously evaluated.

L-22-249 Page 8 of 9 Therefore, the proposed changes do 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.

No new accident scenarios, failure mechanisms, or limiting single failures are introduced as a result of the proposed changes. The systems, structures, and components previously required for the mitigation of a transient remain capable of fulfilling their intended design functions. The proposed changes have no adverse effects on a safety-related systems or components and do not challenge the performance or integrity of safety related systems. As such, the changes do not introduce a mechanism for initiating a new or different accident than those described in the Updated Safety Analysis Report.

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

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

Response: No.

The proposed changes will continue to ensure the DGs are able to perform their design function as assumed in calculations that evaluate their function during design basis accidents. The proposed changes to the testing requirements for the plant DGs do not affect the operability requirements for the DGs, as verification of such operability will continue to be performed as required. Continued verification of operability supports the capability of the DGs to perform their required function of providing emergency power to engineered safety feature systems. Only one DG is tested at a time and the remaining DG will be available to safely shut down the plant or respond to a design basis accident, if required. In addition, the proposed change involves no changes to safety setpoints or limits established or assumed by the accident analysis.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Based on the above, Energy Harbor Nuclear Corp. concludes that the proposed amendment does not involve a significant hazards consideration under the L-22-249 Page 9 of 9 standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of no significant hazards consideration is justified.

4.3 Conclusions 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 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.

6.0 REFERENCES

1. Technical Specifications Task Force Traveler (TSTF) TSTF-276-A, Revision 2, "Revise DG full load rejection test."

2. NUREG 1434, Revision 5, Standard Technical Specifications (STS) General Electric Plants, BWR/6.

3. Wolf Creek License Amendment Request to Revise Technical Specification 3.8.1, "AC Sources - Operating," Surveillance Requirements 3.8.1.10 and 3.8.1.14.

(ML15273A156)

4. Wolf Creek Generating Station - Issuance of Amendment RE: Revise Technical Specification Surveillance Requirements 3.8.1.10 and 3.8.1.14. (ML16081A194)

Attachment 2 L-22-249 Technical Specification Page Markups (2 pages follow)

AC Sources - Operating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.9 ------------------------------NOTES-----------------------------

1. This Surveillance shall not be performed in MODE 1 or 2 (not applicable to Division 3).

However, credit may be taken for unplanned events that satisfy this SR.

2. If performed with DG synchronized with offsite power, it shall be performed at a power factor 0.9. However, if grid conditions do not permit, the power factor limit is not required to be met.

Under this condition the power factor shall be maintained as close to the limit as practicable. In accordance

with the Surveillance Verify each DG rejects a load greater than or equal Frequency to its associated single largest post-accident load. Control Program Following load rejection, engine speed is maintained less than normal plus 75% of the difference between nominal speed and the overspeed trip setpoint, or 15% above nominal, whichever is less.

SR 3.8.1.10 ------------------------------NOTES-----------------------------

1. This Surveillance shall not be performed in MODE 1 or 2 (not applicable to Division 3).

However, credit may be taken for unplanned events that satisfy this SR.

2. If performed with DG synchronized with offsite power, it shall be performed at a power factor In accordance 0.9. However, if grid conditions do not permit, with the the power factor limit is not required to be met. Surveillance Under this condition the power factor shall be Frequency maintained as close to the limit as practicable. Control Program Verify each DG operating at a power factor 0.9 does not trip and voltage is maintained 4784 V for Division 1 and 2 DGs and 5000 V for Division 3 DG during and following a load rejection of a load 5600 kW for Division 1 and 2 DGs and 2600 kW for Division 3 DG.

(continued)

PERRY - UNIT 1 3.8-8 Amendment No. 171

AC Sources - Operating 3.8.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.14 ------------------------------NOTES-----------------------------

1. Momentary transients outside the load and power factor ranges do not invalidate this test.

2. Credit may be taken for unplanned events that satisfy this SR.

3. If performed with DG synchronized with offsite power, it shall be performed at a power factor In accordance 0.9 for Division 1, 2, and 3 DGs. However, if with the grid conditions do not permit, the power factor Surveillance limit is not required to be met. Under this Frequency condition the power factor shall be maintained Control Program as close to the limit as practicable.

Verify each DG operating at a power factor 0.9 operates for 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months s:

a. For 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months loaded 6800 kW and 7000 kW for Division 1 and 2 DGs, and 2860 kW for Division 3 DG; and

b. For the remaining hours of the test loaded 5600 kW and 7000 kW for Division 1 and 2 DGs, and 2600 kW for Division 3 DG.

(continued)

PERRY - UNIT 1 3.8-11 Amendment No. 171

Attachment 3 L-22-249 Technical Specification Pages Retyped (2 pages follow)