W3F1-2020-0014, Response to U. S. Nuclear Regulatory Commission Request for Additional Information Regarding Application for Technical Specification Change to Control Room Air Conditioning System

Response to U. S. Nuclear Regulatory Commission Request for Additional Information Regarding Application for Technical Specification Change to Control Room Air Conditioning System

ML20080L845
Person / Time
Site:	Waterford
Issue date:	03/20/2020
From:	Gaston R Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
W3F1-2020-0014
Download: ML20080L845 (9)

Text

Entergy Operations, Inc.

1340 Echelon Parkway Jackson, MS 39213 Tel 601-368-5138 Ron Gaston Director, Nuclear Licensing 10 CFR 50.90 W3F1-2020-0014 March 20, 2020 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Response to U. S. Nuclear Regulatory Commission Request for Additional Information Regarding Application for Technical Specification Change to Control Room Air Conditioning System Waterford Steam Electric Station, Unit 3 (Waterford 3)

NRC Docket No. 50-382 Renewed Facility Operating License No. NPF-38

References:

1. Entergy Operations, Inc. (Entergy) letter to U. S. Nuclear Regulatory Commission (NRC), "Application for Technical Specification Change to Control Room Air Conditioning System," W3F1-2019-0047, (ADAMS Accession Number ML19239A429), dated August 27, 2019

2. NRC letter to Entergy, " 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)," (ADAMS Accession No. ML20049A410), dated February 20, 2020 By letter dated August 27, 2019 (Reference 1), Entergy requested an amendment to revise Waterford 3 Technical Specification Surveillance Requirement 4.7.6.1.d "Control Room Air Conditioning System."

By letter dated February 20, 2020 (Reference 2), the NRC staff informed Entergy that they have reviewed the license amendment request and have determined that additional information is required to complete the review. A clarification call between the NRC and Entergy was previously held on February 12, 2020.

The additional information requested by the NRC in Reference 2 is provided in the Enclosure to this letter.

W3F1-2020-0014 Page 2 of 2 This letter contains no new regulatory commitments.

Should you have any questions or require additional information, please contact Paul Wood, Regulatory Assurance Manager, at 504-464-3786.

I declare under penalty of perjury, that the foregoing is true and correct. Executed on March 20, 2020.

Respectfully, Ron Gaston RWG/mmz

Enclosure:

Response to NRC Request for Additional Information cc: NRC Region IV Regional Administrator NRC Senior Resident Inspector - Waterford Steam Electric Station, Unit 3 NRR Project Manager Louisiana Department of Environmental Quality, Office of Environmental Compliance

Enclosure W3F1-2020-0014 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION

W3F1-2020-0014 Enclosure Page 1 of 6 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION 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 a loss-of coolant accident.

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 1.197 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.

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 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

W3F1-2020-0014 Enclosure Page 2 of 6 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-bases 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 [sic] 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 Request 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.

Entergy Response Technical Specification Surveillance Requirement 4.7.6.1.g states, "Perform required control room envelope unfiltered air inleakage testing in accordance with the Control Room Envelope Habitability Program." As stated in the basis for Technical Specification 3/4.7.6.1, this Surveillance Requirement verifies the operability of the CRE boundary by testing for unfiltered air inleakage past the CRE boundary and into the CRE. The details of the testing are specified in the Control Room Envelope Habitability Program.

The CRE Habitability Program requires that the unfiltered inleakage is determined at a 6-year frequency. The test results for the requested time frame are provided in Table 1.

W3F1-2020-0014 Enclosure Page 3 of 6 Table 1 Control Room Tracer Gas Test Results (PMRQ 23090-01)

System Operating Mode High Radiation Work Order Date High Radiation without Toxic Gas with pressurization pressurization (168 cfm limit)

(100 cfm limit)

(100 cfm limit) 52432363 02/17/2014 2 scfm 56 scfm 43 scfm 52296611 01/25/2011 46 scfm 79 scfm 103 scfm 00036167 04/17/2004 36 acfm 79 acfm 59 acfm The CRE Habitability Program requires that a Positive Pressure Measurement be performed in accordance with Surveillance Requirement 6.5.17.d at an 18-month frequency on a staggered test basis. This measures the CRE differential pressure relative to all adjacent areas during the pressurization mode of operation by one train of the control room emergency filtration unit, operating at less than or equal to 200 cfm. The results are trended and used as part of the assessment of the CRE boundary. The test results for the requested time frame are provided in Table 2.

Table 2 Positive Pressure Measurement Test Results (PMRQ 3334-01 (B Train) and 3334-02 (A Train)

Results Work Order Date (PA > 0.125 INWC) 52789382 04/22/2019 SAT (B Train) 52817820 10/15/2019 SAT (A Train) 52694902 10/25/2017 SAT (B Train) 52722135 04/12/2018 SAT (A Train) 52590873 05/10/2016 SAT (B Train) 52604182 10/08/2016 SAT (A Train)

There are fourteen CRE boundary valves. These are listed in Table 3.

The CRE Habitability Program requires that Preventive Maintenance (PM) Tasks for integrity be performed on valves HVCMVAAA101 and HVCMVAAA102. These valves are configured such that component testing on each valve is possible; the component test is performed with a smoke tube. There has been no observable leakage at these valves for each of the past four occurrences of these PM tasks. The PM information which includes frequency and history for the requested time frame is provided in Table 4.

W3F1-2020-0014 Enclosure Page 4 of 6 Table 3 Control Room Envelope Boundary Valves Valve Function HVCMVAAA101 Control Room Normal OAI Downstream Isolation HVCMVAAA102 Control Room Normal Outside Air Intake Upstream Isolation HVCMVAAA201A Control Room Emergency Filter Unit North OAI Upstream Isolation HVCMVAAA201B Control Room Emergency Filter Unit North OAI Upstream Isolation HVCMVAAA202A Control Room Emergency Filter Unit North OAI Downstream Isolation HVCMVAAA202B Control Room Emergency Filter Unit North OAI Downstream Isolation HVCMVAAA203A Control Room Emergency Filter Unit South OAI Upstream Isolation HVCMVAAA203B Control Room Emergency Filter Unit South OAI Upstream Isolation HVCMVAAA204A Control Room Emergency Filter Unit South OAI Downstream Isolation HVCMVAAA204B Control Room Emergency Filter Unit South OAI Downstream Isolation HVCMVAAA306 Control Room Toilet Exhaust Fan Upstream Exhaust Damper HVCMVAAA307 Control Room Toilet Exhaust Fan Downstream Exhaust Damper HVCMVAAA313 Kitchen/Conference Exhaust Fan Upstream Exhaust Damper HVCMVAAA314 Kitchen/Conference Exhaust Fan Downstream Exhaust Damper Table 4 Component Testing for Valves HVCMVAAA101 and HVCMVAAA102 HVCMVAAA101 (air operated butterfly valve)

PMRQ Number 2064-02: Performs a leak (smoke) test on the valve on a 104-week frequency Date Work Order Results 11/21/2019 52820196 No leakage observed 01/16/2018 52693267 No leakage observed 04/18/2016 52557957 No leakage observed 11/12/2013 52417636 No leakage observed HVCMVAAA102 (air operated butterfly valve)

PMRQ Number 2066-02: Performs a leak (smoke) test on the valve on a 120-week frequency Date Work Order Results 08/16/2019 52820604 No leakage observed 07/10/2017 52644139 No leakage observed 02/06/2015 52580525 No leakage observed 02/26/2014 52367252 No leakage observed The remaining twelve valves are configured such that component testing on each individual valve is not feasible without removing the valve from the ductwork; thus, no individual component testing has been performed on these valves beyond the unfiltered inleakage and differential pressure testing referenced above.

W3F1-2020-0014 Enclosure Page 5 of 6 PM tasks to clean, inspect, and replace non-metallic parts are required to be performed on all fourteen valves. The PM information which includes frequencies and dates of the last three performances is provided in Table 5 (note: if less than three performance dates are provided, this is because the PM was not required to be performed prior to the performance(s) listed, or, in the case of HVCMVAAA101 and HVCMVAAA102, it is because the individual component testing results were such that replacement was not warranted).

Table 5 PM History to Clean, Inspect, and Replace Non-Metallic Parts Date Valve Type* PRMQ Frequency** Work Order Performed HVCMVAAA101 AOV 2064-01 12-year 250306 04/19/2016 HVCMVAAA102 AOV 2066-01 12-year 250101 02/05/2015 HVCMVAAA201A MOV 2069-01 11-year 314865 01/30/2013 50088831 (MAI 414692) 10/18/2000 HVCMVAAA201B MOV 2070-01 11-year 299076 10/07/2013 50088832 (MAI 414693) 11/16/2000 HVCMVAAA202A MOV 2071-01 11-year 188816 08/30/2011 50213749 (1151649) 06/20/1997 HVCMVAAA202B MOV 2072-01 11-year 187939 10/04/2010 50213750 (1151650) 06/25/1997 HVCMVAAA203A MOV 6953-01 11-year 248347 07/30/2012 50081376 (MAI 407052) 09/09/1999 HVCMVAAA203B MOV 2073-01 11-year 189251 06/25/2014 50080787 (MAI 406427) 07/01/1999 HVCMVAAA204A MOV 2074-01 10-year 187937 05/17/2010 50211419 (1148257) 06/25/1997 HVCMVAAA204B MOV 2075-01 10-year 187935 05/17/2010 50211420 (1148260) 06/25/1997 HVCMVAAA306 AOV 2079-01 12-year 52613442 11/21/2017 238396 05/24/2012 50083915 (MAI 409800) 08/23/2000 HVCMVAAA307 AOV 2081-01 12-year 52543048 06/17/2016 193138 08/06/2009 50213752 (1151652) 06/10/1998 HVCMVAAA313 AOV 2086-01 12-year 52796589 09/24/2019 193536 06/25/2012 50080774 (MAI 406411) 10/20/1999 HVCMVAAA314 AOV 7163-01 12-year 52680152 09/28/2017 229929 08/10/2011 50213754 (1151655) 06/10/1998

• AOV: air operated butterfly valve; MOV: motor operated butterfly valve

• • PM frequency variation is due to varying percentage on late date calculation

W3F1-2020-0014 Enclosure Page 6 of 6 Request 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?

Entergy Response Calculation ECS04-011, Fuel Handling Accident (FHA) Alternative Source Term (AST)

Radiological Dose Consequences for 3716 MWt Extended Power Uprate (EPU) concludes the total dose for the control room in a Fuel Handling Accident is 0.824 Rem Total Effective Dose Equivalent (TEDE) using a total unfiltered in-leakage of 100 cfm throughout the event. The most recent tracer gas test was performed in 2014 under WO-52432363. With the control room isolated in the applicable configuration corresponding to a high radiation signal (control room envelope isolated), the inleakage was tested to be 56 scfm (100 cfm testing acceptance limit);

therefore, the current margin to the assumed inleakage in calculation ECS04-011 is 44 scfm.