ML21327A260

NRR E-mail Capture - Request for Additional Information - Wolf Creek Revision of Technical Specification 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation

ML21327A260
Person / Time
Site:	Wolf Creek
Issue date:	11/23/2021
From:	Samson Lee NRC/NRR/DORL/LPL4
To:	Joseph Turner Wolf Creek
References
L-2021-LLA-0172
Download: ML21327A260 (4)

Text

From: Lee, Samson Sent: Tuesday, November 23, 2021 1:34 PM To: Joshua Turner

Subject:

Request for additional information - Wolf Creek revision of Technical Specification 3.3.2, Engineered Safety Feature Actuation System (ESFAS)

Instrumentation" (EPID L-2021-LLA-0172)

By application dated September 29, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21272A283), Wolf Creek Nuclear Operating Corporation (the licensee) requested changes to the Technical Specifications (TSs) for Wolf Creek Generating Station, Unit 1 (Wolf Creek). The proposed changes would modify TS 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation, by adding a new Required Action N.1 to require restoration of an inoperable balance of plant (BOP) ESFAS train to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The NRC staff has reviewed the license amendment request (LAR) and determined that additional information is required to complete the review. The NRC staffs request for additional information (RAI) is listed below. The staff may have additional RAIs. The licensee and NRC staff held a draft RAI clarification call on November 23, 2021. The licensee staff requested, and NRC staff agreed, to a RAI response by December 23, 2021.

The NRC staff considers that timely responses to RAIs help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. Please note that if you do not respond to this request by the agreed upon date or provide an acceptable alternate date, we may deny your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108. If circumstances result in the need to revise the agreed upon response date, please contact me at (301) 415-3168 or via e-mail Samson.Lee@nrc.gov.

NRC CONSIDERATION OF RISK INSIGHTS The licensee stated that the proposed amendment represents a deterministic based amendment supplemented by risk insight information. Therefore, the NRC staff does not review the licensees probabilistic risk assessment models to determine their technical acceptability.

The NRC staff does not rely on the quantitative risk information provided by the licensee in the LAR. However, the NRC staff considers the licensee-provided qualitative risk insights and associated compensatory measures in its decision on the proposed change.

RAI APLC-1: Inclusion of All Equipment Affected by BOP ESFAS Cabinets in Development of Risk Insights Section 3.1, System Description, of Attachment I to the LAR describes the function of the BOP ESFAS. This section states that the redundant train BOP ESFAS actuation logic cabinets SA036D and SA036E actuate the motor-driven auxiliary feedwater (MDAFW) pumps and reposition automatic valves as required (i.e., steam generator blowdown and sample line isolation valves, essential service water supply valves, and condensate storage tank supply valves). This section further states that these redundant train cabinets also actuate containment purge isolation, control room emergency ventilation isolation, and emergency exhaust system actuation functions.

The auxiliary feedwater system instrumentation and controls are described in Section 7.3.6, Auxiliary Feedwater Supply, of the Updated Safety Analysis Report (USAR) (ADAMS

Accession No. ML21168A142). Section 7.3.6.1.1.g lists the components that are actuated with the auxiliary feedwater system.

Based on the staffs review of the LAR, especially the information in Section 5.10 of Attachment II, the entire set of equipment listed in Section 7.3.6.1.1.g of the USAR does not appear to be included in the development of the risk insights supporting the proposed change. Therefore, it is unclear if the risk insights address all the impacts of the proposed change.

Please address the following:

a. Clarify if all components listed in Section 7.3.6.1.1.g of the USAR are affected by BOP ESFAS actuation logic cabinets SA036D and SA036E. If not all components in Section 7.3.6.1.1.g of the USAR are affected by BOP ESFAS actuation logic cabinets SA036D and SA036E, identify the ones that are affected.

b. Discuss how the risk insights provided in the LAR encompass all potential impacts of the proposed change on the components affected by the BOP ESFAS actuation logic cabinets SA036D and SA036E.

c. Identify any changes to the risk insights supporting the proposed change, if applicable, based on the responses to items a. and b. above.

RAI APLC-2: Risk Management for High-Risk Configurations Section 3.3, Risk Management/Work Control and Scheduling, of Attachment I to the LAR describes how the risk impact of maintenance, testing, and equipment outages is assessed.

This section states that an On-Line Nuclear Safety and Generation Risk Assessment is completed for the current weekly schedule. This section also states that maintenance and testing activities added to the weekly schedule (preplanned or emergent) are assessed for their impact upon the existing On-Line Nuclear Safety and Generation Risk Assessment. This section further states that on-line daily maintenance and testing activities are planned, scheduled, and conducted in a manner to ensure both commercial and nuclear safety issues are assessed and the associated risks are managed. Finally, this section states that risk assessment and management is accomplished, in part, by developing compensatory measures to manage and minimize the operational risks associated with planned or emergent activities that are categorized as risk significant.

The staffs review noted that the LAR does not identify any potentially high-risk configurations that could exist if equipment is taken out of service simultaneously or compensatory measures that can mitigate such configurations. The staff expects the licensee to identify appropriate risk mitigation actions or compensatory measures from the risk insights.

Please address the following:

a. Discuss the potentially high-risk configurations for the proposed change from internal events and internal flood initiators and identify corresponding compensatory measures for managing the risk from such configurations or discuss why compensatory measures are unnecessary for the proposed change.

b. Discuss how it will be ensured that any required compensatory measures based on the emergent condition(s) that occur while in the proposed Required Action N.1 are identified and implemented prior to the expiration of the 24-hour completion time.

Docket No. 50-482

Hearing Identifier: NRR_DRMA Email Number: 1428 Mail Envelope Properties (SA1PR09MB8653AD5AACE094E42C03DA499A609)

Subject:

Request for additional information - Wolf Creek revision of Technical Specification 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation" (EPID L-2021-LLA-0172)

Sent Date: 11/23/2021 1:33:49 PM Received Date: 11/23/2021 1:33:00 PM From: Lee, Samson Created By: Samson.Lee@nrc.gov Recipients:

"Joshua Turner" <Josh.Turner@evergy.com>

Tracking Status: None Post Office: SA1PR09MB8653.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 6359 11/23/2021 1:33:00 PM Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: