ML20049A410

Request for Additional Information Regarding License Amendment Request to Revise Surveillance Requirement 4.7.6.1.d, Control Room Air Filtration System

ML20049A410
Person / Time
Site:	Waterford
Issue date:	02/20/2020
From:	April Pulvirenti Plant Licensing Branch IV
To:	Entergy Operations
Pulvirenti A
References
EPID L-2019-LLA-0187
Download: ML20049A410 (6)

Text

February 20, 2020 Site Vice President Entergy Operations, Inc.

Waterford Steam Electric Station, Unit 3 17265 River Road Killona, LA 70057-3093

SUBJECT:

WATERFORD STEAM ELECTRIC STATION, UNIT 3 -REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO REVISE SURVEILLANCE REQUIREMENT 4.7.6.1.d, CONTROL ROOM AIR FILTRATION SYSTEM (EPID L-2019-LLA-0187)

Dear Sir or Madam:

By letter dated August 27, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19239A429), Entergy Operations, Inc. submitted a license amendment request for Waterford Steam Electric Station, Unit 3. The proposed amendment would modify Surveillance Requirements 4.7.6.1.d.2 and 4.7.6.1.d.4 in Technical Specification Section 3/4.7.6, Control Room Air Filtration System. Specifically, the proposed change would add an exception for automatic dampers and valves that are locked, sealed, or otherwise secured in the actuated position in Modes 5, 6, or defueled, in order to consider the surveillance requirement met.

After reviewing your request, the U.S. Nuclear Regulatory Commission staff has determined that additional information is required to complete its review. The additional information needed to complete the review is delineated in the enclosure to this letter.

During a clarification call held on February 12, 2020, with Maria Zamber of your staff, it was agreed that a response would be provided by 30 days after the date of this letter. Please note that if you do not respond to this letter by the agreed-upon date or provide an acceptable alternate date in writing, we may deny your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108, Denial of application for failure to supply information.

If you have any questions, please contact me at 301-415-1390 or via e-mail at April.Pulvirenti@nrc.gov.

Sincerely,

/RA/

April L. Pulvirenti, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-382

Enclosure:

Request for Additional Information cc: Listserv

ML20049A410 *via e-mail OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NRR/DSS/SCPB*

NAME APulvirenti PBlechman BWittick DATE 2 / 19 / 2020 2 / 19 / 2020 1/31/2020 OFFICE NRR/DORL/LPL4/BC NRR/DORL/LPL4/PM NAME JDixon-Herrity APulvirenti DATE 2 / 20 / 2020 2 / 20 / 2020 REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST REGARDING THE REVISION OF SURVEILLANCE REQUIREMENT 4.7.6.1.d ENTERGY OPERATIONS, INC.

WATERFORD STEAM ELECTRIC STATION, UNIT 3 By letter dated August 27, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19239A429), Entergy Operations, Inc. (the licensee) submitted a license amendment request for Waterford Steam Electric Station, Unit 3 (Waterford 3). The proposed amendment would modify Surveillance Requirements (SRs) 4.7.6.1.d.2 and 4.7.6.1.d.4 in Technical Specification Section 3/4.7.6, Control Room Air Filtration System.

Specifically, the proposed change would add an exception for automatic dampers and valves that are locked, sealed, or otherwise secured in the actuated position in Modes 5, 6, or defueled, in order to consider the SR met.

After reviewing your request, the U.S. Nuclear Regulatory Commission (NRC) staff has determined that additional information is required to complete its review. The request is described below.

Regulatory Requirement Appendix A, General Design Criteria for Nuclear Power Plants, to Title 10 of the Code of Federal Regulations Part 50, General Design Criterion (GDC)-19, Control Room, states, in part:

A control room shall be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions, including loss-of coolant accidents.

Adequate radiation protection shall be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of 5 rem [roentgen equivalent man] whole body, or its equivalent to any part of the body, for the duration of the accident.

Discussion Regulatory Guide (RG) 1.197, Demonstrating Control Room Envelope Integrity at Nuclear Power Reactors, dated May 2003 (ADAMS Accession No. ML031490664), provides an approach acceptable to the NRC staff for measuring inleakage into the control room and associated rooms and areas at nuclear power reactors. The amount of inleakage is an input to the design of the control room, and periodic verification of the inleakage provides assurance that the control room will be habitable during normal and accident conditions. RG 1.1.97 provides guidance on methods acceptable to the NRC staff for determining control room envelope (CRE) integrity for the purpose of confirming that the reactor meets GDC 19.

Enclosure

RG 1.197, Section B., Discussion, states, in part:

The capability to meet GDC-19 is a function of the integrity of the environment surrounding the operators. Lack of integrity jeopardizes the operators ability to control the reactor and to maintain it in a safe condition.

During the design of a nuclear power plant, analyses are performed to demonstrate that the plant will provide a habitable environment for the control room operators during postulated design basis events. These analyses are performed assuming a certain amount of inleakage. Unanticipated increases in the amount of contaminants entering the CRE may have an adverse effect on the ability of the operator to perform plant control functions. If the response of the operator to accident events is impaired, there could be increased consequences to the public health and safety.

The integrity of the CRE can be affected by gradual degradation in associated equipment such as seals, floor drain traps, fans, ductwork and other components; drift in throttled dampers; maintenance on the CRE boundary; changes in differential pressures caused by ventilation system changes; and inadvertent misalignments of ventilation systems. Since inleakage is a function of pressure differentials between the CRE and external areas, changes in air pressures in these areas can impact the CRE inleakage. These changes could be the result of modification or degradation of the ventilation systems serving these areas.

Preventive and corrective maintenance programs, in conjunction with periodic integrity testing, provide a level of confidence that control room habitability is being maintained.

The NRC staff notes that Waterford 3 has in place a control room emergency air filtration system (CREAFS), which is designed to maintain a habitable environment in the CRE following a design-basis accident without exceeding a 5 rem whole body dose or its equivalent to any part of the body, 5 rem total effective dose equivalent. The CREAFS consist of two redundant trains, each capable of maintaining the habitability of the CRE, and the CRE boundary is considered operable when the measured unfiltered air inleakage is less than or equal to the inleakage value assumed by the licensing basis analysis of design-basis accident consequences to CRE occupants.

The NRC staff also notes that the license amendment request references Section 3.2 of Amendment No. 218, issued by letter dated February 20, 2009 (ADAMS Accession No. ML090360713), which implemented Technical Specifications Task Force (TSTF) Traveler TSTF-448, Revision 3, Control Room Habitability, which was approved by the NRC staff on January 17, 2007. The safety evaluation for Amendment No. 218 specifically addresses the situation when one CREAFS is inoperable during movement of irradiated fuel assemblies. The safety evaluation for Amendment No. 218 states, in part, that placing the operable train in service ensures that the safety function can be carried out if an accident occurs.

The licensee stated that prior to a planned electrical bus outage on a given train, the CREAFS system would be placed in the ISOLATE mode, which closes the outside air intake valves that are part of the CRE boundary, and then power would be removed. The licensee further stated that closed valves, which have acceptable leakage performance that are subsequently deenergized, do not impact CRE boundary operability.

Request for Additional Information:

1. Since the operability of the CRE boundary is contingent on the leak-tightness of the CRE boundary valves, the NRC staff requests, for all CRE boundary ventilation dampers and valves, the testing frequency of the dampers and valves, along with the results of at least three preventive maintenance tests or surveillances, in order to ensure CRE boundary operability is maintained.

2. Based on the amount of inleakage assumed in the dose analyses for a fuel handling accident, what is the margin of inleakage assumed versus the actual total inleakage for the CRE boundary?