ML24295A184

SNC Slides - Hatch Public Pre-Submittal Meeting on Oct 30, 2024 - Change EDG SRs 3.8.1.2 & 3.8.1.5 Load Bands

ML24295A184
Person / Time
Site:	Hatch
Issue date:	10/16/2024
From:	Southern Nuclear Operating Co
To:	Dawnmathews Kalathiveettil NRC/NRR/DORL/LPL2-1
Kalathiveettil, D
Shared Package
ML24295A186	List: ML24295A184
References
EPID L-2024-LLA-0054
Download: ML24295A184 (1)

Text

Proposed Hatch Nuclear Plant Units 1 & 2 License Amendment Request

Revise Technical Specification Surveillance Requirements for Diesel Generator Loading Presubmittal Meeting: October 30, 2024 Agenda

• Description

• System Description

• History

• Technical Evaluation

• Justification

• Regulatory Evaluation

• Precedent

• Schedule

• Discussion Revise Technical Specification Surveillance Requirements for Diesel Generator Loading

Description

• The proposed amendment revises the Surveillance Requirement (SR) diesel generator (DG) loading required by SR 3.8.1.2 and SR 3.8.1.5. Specifically, the proposed change would replace the current DG loading requirements with a loading requirement of 90 to 100% of the continuous rating for the DGs.

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System Description===

• The standby ac power supply consists of five DGs for both HNP 1 and 2.

• Diesel generators 1A, 1C, 2A, and 2C each supply an emergency bus. Diesel generator 1B can supply either 4160-V emergency bus 1F (Unit 1) or 2F (Unit 2).

• All DGs have the following ratings:

a. 2850 kW - continuous

b. 3100 kW - 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />,

c. 3250 kW - 300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br />, and

d. 3500 kW - 30 minutes

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History

• In 1987, Amendments 147 and 83 (ML012970477) established the current DG loading for SR 3.8.1.2 and SR 3.8.1.5.

• SR 3.8.1.2 - The basis for the loading was to implement the manufacturer's recommended testing and to verify starting and load handling capability. The diesel manufacturer recommended that the DGs always be loaded to a minimum of 60% of rated load when started during routine testing. A load range was established to make it simpler to load the DGs for testing.

• SR 3.8.1.5 - The basis for the loading was the load distribution on emergency buses for HNP Unit 2 and a higher rating than the 60% minimum for the monthly test for HNP Unit 1.

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Technical Specifications SR 3.8.1.2 Verify each DG:

a. Starts from standby conditions and achieves steady state voltage 3740 V and 4243 V and frequency 58.8 Hz and 61.2 Hz; and

b. Operates for 60 minutes at a load 1710 kW and 2000 kW.

This test is performed monthly in accordance with the Surveillance Frequency Control Program The Unit 1 and Unit 2 TS are identical.

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Technical Specifications SR 3.8.1.5 - Unit 1 Verify each DG:

a. Starts from standby conditions and achieves, in 12 seconds, voltage 3740 V and frequency 58.8 Hz and after steady state conditions are reached, maintains voltage 3740 V and 4243 V and frequency 58.8 Hz and 61.2 Hz; and

b. Operates for 60 minutes at a load 2250 kW and 2400 kW for DGs 1A and 1C, and 2360 kW and 2425 kW for DG 1B.

This test is performed semi-annually in accordance with he Surveillance Frequency Control Program.

Loading requirements are the same between Units for the shared DG (DG 1C)

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Technical Specifications SR 3.8.1.5 - Unit 2 Verify each DG:

a. Starts from standby conditions and achieves, in 12 seconds, voltage 3740 V and frequency 58.8 Hz and after steady state conditions are reached, maintains voltage 3740 V and 4243 V and frequency 58.8 Hz and 61.2 Hz; and

b. Operates for 60 minutes at a load 2764 kW and 2825 kW for DG 2A, 2360 kW and 2425 kW for DG 1B, and 2742 kW and 2825 kW for DG 2C.

This test is performed semi-annually in accordance with he Surveillance Frequency Control Program.

Loading requirements are the same between Units for the shared DG (DG 1C)

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Technical Evaluation - SR 3.8.1.2 - both Units

• The industry now recommends operating the DG at 90-100% of the continuous rating when operated for routine testing.

• Therefore, this LAR requests that the loading range for SR 3.8.1.2 be changed to reflect 90-100% of the continuous rating of each DG.

- The lower limit of the load band ensures the DG is sufficiently loaded during the test and the upper limit of the load band is to avoid an overload condition during routine testing.

- The upper and lower limits provide a reasonable band to operate the DG in for the specified run time while achieving the intent of a full load.

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Technical Evaluation - SR 3.8.1.2 - both Units

DG SR 3.8.1.2 Current Percent SR 3.8.1.2 Percent Load Range Continuous Rating Proposed Load Continuous Rating Range

1A 1710 kW and 60% to 70% 2565 kW and 90% to 100%

2000 kW 2850 kW

1B 1710 kW and 60% to 70% 2565 kW and 90% to 100%

2000 kW 2850 kW

1C 1710 kW and 60% to 70% 2565 kW and 90% to 100%

2000 kW 2850 kW

2A 1710 kW and 60% to 70% 2565 kW and 90% to 100%

2000 kW 2850 kW

2B 1710 kW and 60% to 70% 2565 kW and 90% to 100%

2000 kW 2850 kW

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TECHNICAL Evaluation - SR 3.8.1.5 - both Units

• The industry now recommends operating the DG at 90-100% of the continuous rating when operated for routine testing.

• For HNP Unit 1, the proposed change will improve DG testing by demonstrating the ability of the DGs to run loaded to between 90 and 100% of their continuous rating. This is an increase in the load requirements for DGs 1A, 1B and 1C.

• For HNP Unit 2, the proposed change will create consistent testing conditions for all the DGs between Unit 1 and Unit 2 by enlarging the load window for DG testing and increase it to 100% of the continuous rating.

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Technical Evaluation - SR 3.8.1.5 - both Units

DG SR 3.8.1.5 Current Percent SR 3.8.1.5 Percent Load Range Continuous RatingProposed Load Continuous Rating Range

1A 2250 kW and 79% to 84% 2565 kW and 90% to 100%

2400 kW 2850 kW

1B 2360 kW and 83% to 85% 2565 kW and 90% to 100%

2425 kW 2850 kW

1C 2250 kW and 79% to 84% 2565 kW and 90% to 100%

2400 kW 2850 kW

2A 2764 kW and 97% to 99% 2565 kW and 90% to 100%

2825 kW 2850 kW

2B 2742 kW and 96% to 99% 2565 kW and 90% to 100%

2825 kW 2850 kW

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Justification

• The purpose of the one hour loaded run is to verify that the DG can start and is ready to accept load, not to verify the endurance limits of the DGs.

- DG loading levels are verified during the performance of the 24-hour endurance run. The loading criteria for the 24-hour endurance test is unchanged.

• RG 1.9, Revision 3, Section 2.2.2, "Load-Run Test" stipulates that the monthly test be performed with the DG at a load of 90% to 100% of the DG continuous rating for not less than 1-hour.

- Note Hatch is not committed to Revision 3 of RG 1.9.

• The acceptance criterion for the test remains the stabilization of the voltage and frequency within the prescribed acceptable limits. In addition, all parameters monitoring the condition of the running engine are expected to stabilize within the 1-hour test duration.

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Regulatory Evaluation

Unit 2 is committed to RG 1.9, revision 0 and discusses RG 1.108. Unit 1 is not committed to either RG. The combination of RG 1.9 and RG 1.108 created RG 1.9, revision 3 which is the basis for acceptability of the requested change.

Regulatory Guide 1.9, Revision 0

This RG provides an acceptable basis for the selection of a DG set of sufficient capacity and margin to implement GDC 17. This change is consistent with the design criteria of RG 1.9, Revision 0.

Regulatory Guide 1.108

This RG provides design and operational provisions for the performance of periodic testing of DG units used for onsite electric power for nuclear power plants. This change is consistent with the testing requirements of RG 1.108.

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Precedent

• Salem

- Salem requested a change to the DG loading for the monthly testing based on consistency with RG 1.9, Revision 3. The NRC approved the request on that basis.

• Letter from NRC to PSE&G, Issuance of Amendment re: Technical Specifications Section 3/4.8.1 AC Sources, dated April 2, 2001 (ADAMS Accession No. ML010580304)

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Remaining Actions and Schedule

• NRC Pre-Submittal Meeting 10/30/2024

• Submit LAR to NRC 12/17/2024

• Requested Approval by NRC 1 year from completion of acceptance review

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Discussion / Feedback

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