L-PI-23-025, License Amendment Request to Revise Technical Specification 3.8.1, Surveillance Requirement 3.8.1.2, Note 3

License Amendment Request to Revise Technical Specification 3.8.1, Surveillance Requirement 3.8.1.2, Note 3

ML23271A205
Person / Time
Site:	Prairie Island
Issue date:	09/28/2023
From:	Conboy T Northern States Power Company, Minnesota, Xcel Energy
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-PI-23-025
Download: ML23271A205 (1)

Text

1717 Wakonade Drive Welch, MN 55089 September 28, 2023 L-PI-23-025 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant, Units 1 and 2 Docket Nos. 50-282 and 50-306 Renewed Facility Operating License Nos. DPR-42 and DPR-60 License Amendment Request to Revise Technical Specification 3.8.1, Surveillance Requirement 3.8.1.2, Note 3 Pursuant to 10 CFR 50.90, Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter NSPM), hereby requests an amendment to the Technical Specifications (TS) for the Prairie Island Nuclear Generating Plant (PINGP). The proposed change would revise Note 3 of TS Surveillance Requirement (SR) 3.8.1.2 to remove detail that is not needed to ensure operability.

The enclosure provides NSPMs evaluation of the proposed change. Attachment 1 to the enclosure provides the marked-up PINGP TS pages. Attachment 2 to the enclosure provides re-typed copies of the PINGP TS pages. Attachment 3 to the enclosure provides the marked-up PINGP TS Bases pages, which are being provided for information only.

NSPM has evaluated the changes proposed in this License Amendment Request (LAR) in accordance with 10 CFR 50.92 and concluded that they involve no significant hazards consideration. In accordance with 10 CFR 50.91(b)(1), a copy of this application, with the enclosure, is being provided to the designated Minnesota official.

NSPM requests approval of the proposed amendment 12 months after NRC acceptance. Once approved, the amendment shall be implemented within 90 days.

If there are any questions or if additional information is required, please contact Mr. Jeff Kivi at (612) 330-5788.

Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

(l Xcel Energy

Document Control Desk L-Pl-23-025 Page 2 I declare under penalty of perjury, that the foregoing is true and correct.

Executed on -----

Thomas A. Conboy Site Vice President, Prairie Island ~clea Generating Plant Northern States Power Company - lv1in esota Enclosure cc:

Administrator, Region Ill, USNRC Project Manager, Prairie Island, USNRC Resident Inspector, Prairie Island, USNRC State of Minnesota September 28, 2023.

Page 1 of 6 ENCLOSURE PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 Description and Assessment of the Proposed Change License Amendment Request to Revise Technical Specification 3.8.1, Surveillance Requirement 3.8.1.2, Note 3 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION 2.1 System Design and Operation 2.2 Current Technical Specification Requirements 2.3 Reason for Proposed Changes 2.4 Description of Proposed Changes

4.0 REGULATORY ANALYSIS

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

5.0 ENVIRONMENTAL CONSIDERATION

ATTACHMENTS:

1. Technical Specification Pages (Markup)

2. Technical Specification Pages (Retyped)

3. Technical Specification Bases Pages (Markup - for information only)

L-PI-23-025 NSPM Enclosure Page 2 of 6 1.0

SUMMARY

DESCRIPTION Pursuant to 10 CFR 50.90, Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter NSPM), hereby requests an amendment to the Technical Specifications (TS) for the Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2, Renewed Facility Operating License Nos. DPR-42 and DPR-60. The proposed change would revise Note 3 of TS Surveillance Requirement (SR) 3.8.1.2 to remove detail that is not needed to ensure operability.

2.0 DETAILED DESCRIPTION 2.1 System Design and Operation Units 1 and 2 at PINGP each have dedicated emergency diesel generators (referred to in TS as DGs). Each DG is automatically started by either of the following events:

a. Undervoltage, which envelopes loss of voltage, including a loss of offsite power (LOOP), or degraded voltage on the associated 4160 Volt buses. Automatic starting of the DGs is initiated by a modified 2-out-of-4 voltage relay scheme on each 4160 Volt bus to which the DG is to be connected.

b. Initiation of a Safety Injection (SI) signal (both of the affected Units DGs start on this signal).

Loading on the DGs is analyzed for a worst case condition as represented by a SI signal coincident with a LOOP. However, a small break loss of coolant accident (LOCA) that was sufficient to initiate automatic SI action would represent the same inrush KVA load on the DG.

If the break is so small that automatic SI is not initiated, manual action would be required as soon as the operator is aware of the break. Manual action would represent loads less than or equal to that analyzed in the calculations for an automatic SI initiation.

SR 3.8.1.2 (slow start) and SR 3.8.1.6 (fast start) help to ensure availability of the standby electrical power supply to mitigate design bases accidents and transients and to maintain the unit in a safe shutdown condition. The slow start test of SR 3.8.1.2 is performed on a 62-day frequency and is intended to reduce stress and wear on the diesel engines. The fast start of SR 3.8.1.6 is performed on a 184-day frequency and is more restrictive than the slow start of SR 3.8.1.2 and requires a ten-second start and may be performed in lieu of SR 3.8.1.2 as noted in Note 1 to SR 3.8.1.2.

L-PI-23-025 NSPM Enclosure Page 3 of 6 2.2 Current Technical Specification Requirements SR 3.8.1.2, Note 3 states:

3. A modified DG start involving idling and gradual acceleration to synchronous speed may be used for this SR in consideration of manufacturers recommendations. When modified start procedures are not used, the time, voltage, and frequency tolerances of SR 3.8.1.6 must be met.

2.3 Reason for Proposed Changes SR 3.8.1.2, Note 3, contains details that are not necessary to ensure operability; therefore, these details are not required to be in the TS to provide adequate protection of the public health and safety. Details for performing required actions and surveillances or statements providing clarification of the technical specification requirement are more appropriately specified in the TS Bases, USAR, or other licensee controlled document that is subject to 10 CFR 50.59 or a TS requirement.

2.4 Description of Proposed Changes NSPM proposes to revise SR 3.8.1.2, Note 3, to:

3. A modified DG start may be used for this SR. When modified start procedures are not used, the time, voltage, and frequency tolerances of SR 3.8.1.6 must be met.

The specific changes are provided in markup form in Attachment 1 to this Enclosure and the proposed final SR 3.8.1.2, Note 3, is provided in Attachment 2 to this Enclosure.

3.0 TECHNICAL EVALUATION

The proposed change to SR 3.8.1.2, Note 3, will remove detail from TS that is not necessary to ensure operability. Detail to provide consistent implementation of the TS is located in other licensee-controlled documents. NSPM considers manufacturers recommendations as part of operating and testing procedures and proposed design modifications.

NSPM operating and testing procedures are informed by design specifications, vendor technical manuals, and the operating experience program that has diverse inputs including NRC generic correspondence, notifications from the Institute of Nuclear Power Operations (INPO), and technical bulletins from manufacturers. Therefore, it is not necessary to specify consideration of manufacturers recommendations for DG starting in SR 3.8.1.2, Note 3. The details of what constitutes a modified start, such as idling and acceleration, are more appropriately located in other licensee-controlled documents.

L-PI-23-025 NSPM Enclosure Page 4 of 6

4.0 REGULATORY ANALYSIS

4.1 Applicable Regulatory Requirements/Criteria 10 CFR 50.36, Technical specifications, establish the requirements related to the content of the TS. Section 50.36(c)(3) states:

Surveillance requirements 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.

The proposed change would revise Note 3 of TS Surveillance Requirement (SR) 3.8.1.2 to remove detail that is not needed to ensure operability. SR 3.8.1.2 will continue to assure necessary quality of the DGs is maintained and that Limiting Condition for Operation 3.8.1 will continue to be met. Therefore, 10 CFR 50.36(c)(3) will continue to be met.

4.1.1 Principal Design Criteria PINGP was designed and constructed to comply with NSPMs understanding of the intent of the AEC General Design Criteria (GDC) for Nuclear Power Plant Construction Permits, as proposed on July 10, 1967. Since the construction of the plant was significantly completed prior to the issuance of the February 20, 1971, 10CFR50, Appendix A GDC, the plant was not reanalyzed and the Final Safety Analysis Report (FSAR) was not revised to reflect these later criteria. However, the AEC Safety Evaluation Report acknowledged that the AEC staff assessed the plant, as described in the FSAR, against the Appendix A design criteria and...

are satisfied that the plant design generally conforms to the intent of these criteria.

Criterion 39 - Emergency Power For Engineered Safety Features Alternate power systems shall be provided and designed with adequate independency, redundancy, capacity, and testability to permit the functioning required of the engineered safety features. As a minimum, the onsite power system and the offsite power system shall each, independently, provide this capacity assuming a failure of a single active component in each power system.

Reliability of electric power supply is insured through two independent connections to the system grid, and a redundant source of emergency power from four diesel generators installed in the facility. Power to the engineered safety features is assured even with the failure of a single active component in each system.

The proposed change has no effect on how PINGP DGs comply with Criterion 39. No changes are made to the plant and testability is unchanged.

L-PI-23-025 NSPM Enclosure Page 5 of 6 Conclusion The change proposed to the TS will not affect any installed components at PINGP. The change proposed to the TS simplifies and eliminates an unnecessary reference to manufacturers recommendations in Note 3 to SR 3.8.1.2. Therefore, the criteria listed above, and as described in the PINGP USAR, will continue to be met.

4.2 No Significant Hazards Consideration Analysis In accordance with the requirements of 10 CFR 50.90, Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter NSPM), requests an amendment to the Technical Specifications (TS) for the Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2, Renewed Facility Operating License Nos. DPR-42 and DPR-60.

The proposed change would revise Note 3 of TS Surveillance Requirement (SR) 3.8.1.2 to remove detail that is not needed to ensure operability.

NSPM has evaluated the proposed amendment against the standards in 10 CFR 50.92 and has determined that the operation of the PINGP in accordance with the proposed amendment presents no significant hazards. NSPMs evaluation against each of the criteria in 10 CFR 50.92 follows.

1.

Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed TS change does not introduce new equipment or new equipment operating modes, nor does the proposed change alter existing system relationships.

The proposed change does not affect normal plant operation. Further, the proposed change does not increase the likelihood of the malfunction of any system, structure or component or impact any analyzed accident.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2.

Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operations. The proposed change does not alter assumptions made in the safety analysis. Further, the proposed change does not introduce new accident initiators.

L-PI-23-025 NSPM Enclosure Page 6 of 6 Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3.

Does the proposed change involve a significant reduction a margin of safety?

Response: No The proposed change does not alter the manner in which safety limits, limiting safety system settings, or limiting conditions for operation are determined. The safety analysis assumptions and acceptance criteria are not affected by this change.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above evaluation, NSPM 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.

4.3 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

NSPM 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 effluent 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, ATTACHMENT 1 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 License Amendment Request to Revise Technical Specification 3.8.1, Surveillance Requirement 3.8.1.2, Note 3 TECHNICAL SPECIFICATION PAGES (Markup)

(2 pages follow)

AC Sources-Operating 3.8.1 Prairie Island Units 1 and 2 3.8.1-6 Unit 1 - Amendment No. 235 Unit 2 - Amendment No. 223 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.1.1 Verify correct breaker alignment and indicated power availability for each required path.

In accordance with the Surveillance Frequency Control Program SR 3.8.1.2

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NOTES--------------------------

1.

Performance of SR 3.8.1.6 satisfies this SR.

2.

All DG starts may be preceded by an engine prelube period and followed by a warmup period prior to loading.

3.

A modified DG start involving idling and gradual acceleration to synchronous speed may be used for this SR in consideration of manufacturers recommendations. When modified start procedures are not used, the time, voltage, and frequency tolerances of SR 3.8.1.6 must be met.

Verify each DG starts from standby conditions and achieves steady state voltage > 4084 V and

< 4400 V, and frequency > 59.5 Hz and < 60.5 Hz.

In accordance with the Surveillance Frequency Control Program

AC Sources-Operating 3.8.1 Prairie Island Units 1 and 2 3.8.1-8 Unit 1 - Amendment No. 235 Unit 2 - Amendment No. 223 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.1.6 ----------------------------NOTE---------------------------

All DG starts may be preceded by an engine prelube period.

Verify each DG starts from standby condition and achieves:

a.

In < 10 seconds, voltage > 3740 V and frequency > 58.8 Hz; and b.

Steady state voltage > 4084 V and < 4400 V, and frequency > 59.5 Hz and < 60.5 Hz.

In accordance with the Surveillance Frequency Control Program SR 3.8.1.7 Verify each DG does not trip during and following a load rejection of:

1.

Unit 1 > 650 kW; and 2.

Unit 2 > 860 kW.

In accordance with the Surveillance Frequency Control Program SR 3.8.1.8 Verify each DG's automatic trips are bypassed on an actual or simulated safety injection signal except:

a.

Engine overspeed; b.

Generator differential current; and c.

Ground fault (Unit 1 only).

In accordance with the Surveillance Frequency Control Program No changes. Included for information on SR 3.8.1.6.

ENCLOSURE, ATTACHMENT 2 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 License Amendment Request to Revise Technical Specification 3.8.1, Surveillance Requirement 3.8.1.2, Note 3 TECHNICAL SPECIFICATION PAGES (Re-typed)

(1 page follows)

AC Sources-Operating 3.8.1 Prairie Island Unit 1 - Amendment No. TBD Units 1 and 2 3.8.1-6 Unit 2 - Amendment No. TBD SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.1.1 Verify correct breaker alignment and indicated power availability for each required path.

In accordance with the Surveillance Frequency Control Program SR 3.8.1.2

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NOTES--------------------------

1. Performance of SR 3.8.1.6 satisfies this SR.

2. All DG starts may be preceded by an engine prelube period and followed by a warmup period prior to loading.

3. A modified DG start may be used for this SR.

When modified start procedures are not used, the time, voltage, and frequency tolerances of SR 3.8.1.6 must be met.

Verify each DG starts from standby conditions and achieves steady state voltage > 4084 V and

< 4400 V, and frequency > 59.5 Hz and < 60.5 Hz.

In accordance with the Surveillance Frequency Control Program

ENCLOSURE, ATTACHMENT 3 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 License Amendment Request to Revise Technical Specification 3.8.1, Surveillance Requirement 3.8.1.2, Note 3 TECHNICAL SPECIFICATION BASES PAGES (Marked-Up)

(Provided for Information Only)

(2 pages follow)

AC Sources-Operating B 3.8.1 Prairie Island Units 1 and 2 B 3.8.1-13 Revision 261 BASES SURVEILLANCE associated safeguards bus: load rejection; voltage restoration; and REQUIREMENTS load restoration. The voltage restoration portion of the sequence will (continued) connect the DG to the bus if no viable offsite source is available.

The load restoration is accomplished by a series of start permissives separated by 5 second steps. The 5 second steps allow for the starting of the load and voltage recovery prior to starting the next loads which ensures that voltage does not fall below the degraded voltage setting of the bus. The PLC program has the capability to have up to 9 programed load steps which total 45 seconds. Along with a 15 second allowance for the DG to start and come up to rated speed and voltage gives a total transient time of 60 seconds. After 60 seconds the DG is determined to be in a steady state condition.

SR 3.8.1.1 This SR ensures proper circuit continuity for the required offsite AC electrical power supply to the onsite distribution network and availability of offsite AC electrical power. The breaker alignment verifies that each breaker is in its correct position to ensure that distribution buses and loads are connected to their offsite power source, and that appropriate independence of offsite circuits is maintained.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.8.1.2 and SR 3.8.1.6 These SRs help to ensure the availability of the standby electrical power supply to mitigate DBAs and transients and to maintain the unit in a safe shutdown condition. The steady state voltage requirement is to allow the DG to accept loads and to maintain the unit in a safe shutdown condition.

To minimize the wear on moving parts that do not get lubricated when the engine is not running, these SRs are modified by a Note

AC Sources-Operating B 3.8.1 Prairie Island Units 1 and 2 B 3.8.1-14 Revision 261 BASES SURVEILLANCE SR 3.8.1.2 and SR 3.8.1.6 (continued)

REQUIREMENTS (Note 2 for SR 3.8.1.2) to indicate that all DG starts for these Surveillances may be preceded by an engine prelube period and followed by a warmup period prior to loading.

In order to reduce stress and wear on diesel engines, some manufacturers recommend a modified start in which the starting speed of DGs is limited, warmup is limited to this lower speed, and the DGs are gradually accelerated to synchronous speed prior to loading. These start procedures are the intent of Note 3, which is only applicable when such modified start procedures are recommended by the manufacturer.

Since SR 3.8.1.6 requires a 10 second start, it is more restrictive than SR 3.8.1.2, and it may be performed in lieu of SR 3.8.1.2. This is the intent of Note 1 of SR 3.8.1.2.

The Surveillance Frequencies are controlled under the Surveillance Frequency Control Program.

SR 3.8.1.3 This Surveillance verifies that the DGs are capable of synchronizing with the offsite electrical system and accepting loads greater than or equal to 90% of the continuous rating of the DG (Ref. 2). The Unit 1 and Unit 2 diesel generators have different loading requirements since their individual loads are different. As an example, the Unit 2 diesel generators supply emergency power to the cooling water pump whereas the Unit 1 diesel generators do not. A minimum run time of 60 minutes is required to stabilize engine temperatures, while minimizing the time that the DG is connected to the offsite source.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

A modified (slow)

DG start procedure may be used to reduce long-term stress and wear on diesel engines.