ML21252A012

NRR E-mail Capture - Request for Additional Information Amendment Request to Adopt TSTF-471 and 517-T for Prairie Island

ML21252A012
Person / Time
Site:	Prairie Island
Issue date:	08/30/2021
From:	Robert Kuntz NRC/NRR/DORL/LPL3
To:	Kivi J Northern States Power Company, Minnesota
References
Download: ML21252A012 (4)

Text

From: Kuntz, Robert Sent: Monday, August 30, 2021 2:48 PM To: Kivi, Jeffrey L.

Cc: Scott, Sara

Subject:

Request for Additional Information RE: Amendment request to adopt TSTF-471 and 517-T for Prairie Island By letter dated April 19, 2021 (Agencywide Documents Access and Management System (ADAMS) at Accession No. ML21109A385) Northern States Power Company, doing business as Xcel Energy (Xcel Energy), requested an amendment to the Technical Specifications (TS) for the Prairie Island Nuclear Generating Plant (PINGP) Units 1 and 2. The proposed amendment would adopt TSTF-471, Eliminate Use of the Term CORE ALTERATIONS in ACTIONS and Notes, with site-specific variations. The proposed change would eliminate the defined term CORE ALTERATIONS and all uses of the term from the TS and Bases. The proposed amendment would also adopt TSTF-571-T, Revise Actions for Inoperable Source Range Neutron Flux Monitor, which changes TS 3.9.3, Nuclear Instrumentation, to ensure that no actions are taken that could alter the core reactivity when a required core subcritical neutron flux monitor is inoperable. The Nuclear Regulatory Commission (NRC) staff has determined that additional information is required to complete the review of the amendment request. The following is the NRC staffs request for additional information (RAI). During a meeting for the staff to provide clarification on the draft RAI conducted on August 30, 2021 a 30 day response was agreed upon. Therefore, the NRC staff expects a response to this RAI by September 30, 2021. If Xcel Energy has any issues with providing the response contact me.

Robert Kuntz Senior Project Manager (Monticello and Prairie Island)

NRC/NRR/DORL/LPL3 (301) 415-3733 REQUESTS FOR ADDITIONAL INFORMATION ADOPTION OF TSTF-471 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-282 AND 50-306 REGULATORY BASIS Part 50.36, "Technical Specifications," of Title 10 of the Code of Federal Regulations requires, in part, that the operating license of a nuclear production facility include TS. Paragraph 50.36(c)(2) of Title 10 of the Code of Federal Regulations requires, in part, that the TS include limiting conditions for operation (LCOs), which are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When an LCO of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the TS, until the condition can be met.

Appendix A to 10 CFR 50 establishes minimum criteria (General Design Criteria or GDC) for the design of light water reactors. GDC 13 requires that instrumentation be provided to monitor

variables over anticipated ranges for normal operations, for anticipated operational occurrences, and for accident conditions.

Prairie Island Nuclear Generating Plant (PINGP) was not licensed to the 10 CFR 50, Appendix A GDC. PINGP was designed and constructed to comply with the licensees understanding of the intent of the AEC General Design Criteria (AEC 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, 10 CFR 50, Appendix A GDC, the plant was not reanalyzed and the Updated Safety Analysis Report (USAR) 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 USAR, against the Appendix A design criteria and ... are satisfied that the plant design generally conforms to the intent of these criteria. GDC 13 is equivalent to AEC GDC 12 and 13.

RAI-1

The amendment proposes to remove Required Action C.2 from LCO 3.9.3. This Required Action is included in the PINGP technical specifications, but not in the standard technical specifications for Westinghouse plants. Since Technical Specification Task Force (TSTF)

Traveler TSTF-471 was written to modify standard technical specifications (TSs), it does not refer to this Required Action.

This action requires suspension of core alterations when one required core subcritical neutron flux monitor audible count rate circuit is inoperable. However, the basis for this limiting condition of operation states that audible count rate circuits serve to alert the operator in containment in the event of a dilution accident or improperly loaded fuel assembly, as noted in Section 3.1 of the amendment request. The amendment request also stated that considering an improperly loaded fuel assembly in discussion of the audible count rate circuit is not consistent with the rest of the PINGP TS 3.9.3 bases.

Request Describe the portions of PINGPs licensing basis that consider improper loading of a fuel assembly and explain why these basis support removal of Required Action C.2.

RAI-2

Technical or Regulatory Issue In the current TSs, Required Action C.2 of LCO 3.9.3 requires that core alterations be suspended if one required core subcritical neutron flux monitor audible count rate circuit is inoperable. The current LAR proposes to remove this Required Action. Section TS 3.9.3, Required Actions A.1 and C.2 of the LAR, states that this Required Action has no effect on the initial conditions or mitigation of a boron dilution accident. However, as written, the proposed change would allow for positive reactivity additions when in Condition C. This contradicts the statement in section TS 3.9.1 of the LAR that suspending positive reactivity additions is the only action needed to mitigate a boron dilution event. It also appears to be inconsistent with TSTF-471, which explains that suspending core alterations provides no safety benefit if Required Actions that suspend core alterations also suspend movement of recently irradiated fuel. The proposed Required Actions in Condition C would not require suspension of movement of recently irradiated fuel.

Request Please clarify why a requirement to suspend positive reactivity additions or movement of recently irradiated fuel is not needed to replace the requirement to suspend core alterations in Condition C of LCO 3.9.3, and why this change would have no effect on the initial conditions or mitigation of a boron dilution accident in this condition.

Hearing Identifier: NRR_DRMA Email Number: 1329 Mail Envelope Properties (SA9PR09MB4640A454FA74CFC4EC2497EF99CB9)

Subject:

Request for Additional Information RE: Amendment request to adopt TSTF-471 and 517-T for Prairie Island Sent Date: 8/30/2021 2:48:19 PM Received Date: 8/30/2021 2:48:00 PM From: Kuntz, Robert Created By: Robert.Kuntz@nrc.gov Recipients:

"Scott, Sara" <sara.scott@xcelenergy.com>

Tracking Status: None "Kivi, Jeffrey L." <jeffrey.l.kivi@xcelenergy.com>

Tracking Status: None Post Office: SA9PR09MB4640.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 6168 8/30/2021 2:48:00 PM Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: