ML19116A160

Report of Full Compliance with Phase 1 and Phase 2 of June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions .

ML19116A160
Person / Time
Site:	Monticello
Issue date:	04/25/2019
From:	Church C Northern States Power Co, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CAC MF4376, EA-13-109, L-MT-19-020
Download: ML19116A160 (13)

Text

Xcel Energy RESPONSIBLE BY NATURE April 25, 2019 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket No. 50-263 Renewed Facility Operating License No. DPR-22 2807 West County Road 75 Monticello, MN 55362 L-MT-19-020 10 CFR 2.202 EA-13-109 Monticello Nuclear Generating Plant: Report of Full Compliance with Phase 1 and Phase 2 of June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phases 1 and 2 (CAC No. MF4376)

References:

1)

NRC Order Number EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," dated June 6, 2013. (ADAMS Accession No. ML13143A334)

2)

NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with.Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions," Revision 0, dated November 14, 2013. (ADAMS Accession No. ML13304B836)

3)

Letter from D. Skeen (NRC) to J. Pollock (NEI), Endorsement of Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-13-109) Rev 0, dated May 14, 2014. (ADAMS Accession No. ML14128A219)

4)

NEI 13-02, "Industry Guidance for Compliance with Order EA-13-109,"

Revision 0, dated November 2013. (ADAMS Accession No. ML13316A853)

Page 1 of 13

L-MT-19-020

5)

Letter from K. Fili (NSPM) to Document Control Desk (NRC),

"MNGP's Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109),"

L-MT-14-052, dated June 30, 2014. (ADAMS Accession No. ML14183A412).

6)

Letter from K. Fili (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: First Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109)," L-MT-14-092, dated December 16, 2014. (ADAMS Accession No. ML14353A215)

7)

Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: Second Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phase 1," L-MT-15-031, dated June 22, 2015.

(ADAMS Accession No. ML15173A176)

8)

NEI 13-02, "Industry Guidance for Compliance with Order EA-13-109,"

Revision 1, dated April 2015. (ADAMS Accession No. ML151138318)

9)

NRC Interim Staff Guidance JLD-ISG-2015-01, "Compliance with Phase 2 of Order EA-13-109, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions," Revision 0, dated April 2015. (ADAMS Accession No. ML15104A118)

10) Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant's Phase 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109) including Phase 1 Status Report," L-MT-15-090, dated December 17, 2015. (ADAMS Accession No. ML15356A120)

Page 2 of 13

L-MT-19-020

11) Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: Fourth Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phases 1 and 2," L-MT-16-034, dated June 17, 2016. (ADAMS Accession No. ML16169A309)

12) Letter from M. Halter (NRC) to P. Gardner (NSPM), "

Subject:

Monticello Nuclear Generating Plant - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase One of Order EA-13-109 (Severe Accident Capable Hardened Vents) (TAC No. MF4376),"dated April 2, 2015. (ADAMS Accession No. ML15082A167)

13) Letter from J. Quichocho (NRC) to P. Gardner (NSPM), "

Subject:

Monticello Nuclear Generating Plant-Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 2 of Order EA-13-109 (Severe Accident Capable Hardened Vents)

(CAC No. MF4376),"dated September 6, 2016. (ADAMS Accession No. ML16244A120)

14) Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: Fifth Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phases 1 and 2," L-MT-16-072, dated December 19, 2016. (ADAMS Accession No. ML16354A666)

15) Letter from P. Gardner (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: Sixth Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phases 1 and 2," L-MT-17-042, dated June 14, 2017.

(ADAMS Accession No. ML17166A051)

16) Letter from C. Church (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: Seventh Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phases 1 and 2," L-MT-17-081, dated December 21, 2017. (ADAMS Accession No. ML17355A508)

17) Letter from R, Au luck (NRC) to C. Church (NSPM), "

Subject:

Monticello Nuclear Generating Plant - Report for the Audit of Licensee Responses to Interim Staff Evaluations Open Items Related to NRC Order EA-13-109 to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Page 3 of 13

L-MT-19-020 Accident Conditions (CAC NO. MF3476; EPID L-2014-JLD-0052),"

dated April 10, 2018. (ADAMS Accession No. ML18094A804)

18) Letter from R. Auluck (NRC) to C. Church (NSPM), "

Subject:

Monticello Nuclear Generating Plant - Correction to the Audit Report for the Audit of Licensee Responses to Interim Staff Evaluations Open Items Related to NRC Order EA-13-109 to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (CAC NO. MF3476; EPID L-2014-JLD-0052)," dated May 14, 2018. (ADAMS Accession No. ML18130A921)

19) Letter from C. Church (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: Eighth Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phases 1 and 2," L-MT-18-035, dated June 26, 2018. (ADAMS Accession No. ML18177A422)

20) Letter from C. Church (NSPM) to Document Control Desk (NRC),

"Monticello Nuclear Generating Plant: Ninth Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109), Phases 1 and 2," L-MT-18-079, dated December 17, 2018. (ADAMS Accession No. ML18352A254)

On June 6, 2013, the Nuclear Regulatory Commission (NRC) issued Order EA-13-109 (Reference 1) to Northern States Power Company, a Minnesota corporation (NSPM),

doing business as Xcel Energy. Reference 1 was effective immediately and directs NSPM to install a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris, for Monticello Nuclear Generating Plant (MNGP). Specific requirements are outlined in Attachment 2 of Reference 1.

Reference 1 required submission of a Phase 1 Overall Integrated Plan (OIP) pursuant to Section IV, Condition D. References 2 and 3 endorse industry guidance document, NEI 13-02, Revision O (Reference 4) with clarifications and exceptions. Reference 5 provided the MNGP Phase 1 OIP.

Reference 1 requires submission of a status report at six-month intervals following submittal of the Phase 1 OIP. References 2 and 4 provide direction regarding the content of the status reports. References 6 and 7 provided the first and second six-month status reports for Phase 1 of the order.

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L-MT-19-020 In Reference 9, the NRC endorsed industry guidance document NEI 13-02, Revision 1 (Reference 8) with clarifications and exceptions identified in Reference 9. NEI 13-02, Revision 1 provides guidance for implementing Phase 2 of Order EA-13-109.

Reference 10 provided a combined Phase 1 and 2 OIP and provided an updated status of Phase 1 of the order. Reference 11 provided the fourth status report which included both Phase 1 and Phase 2 status updates. In References 12 and 13, the NRC provided interim staff evaluations (ISEs) for HCVS Order Phase 1 and 2 OIPs, respectively. In References 14, 15, 16, 19, and 20 NSPM provided the fifth, sixth, seventh, eighth, and ninth HCVS Order status reports.

The purpose of this letter is to provide the report of full compliance with Phase 1 and Phase 2 of the June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109) (Reference 1) pursuant to Section IV, Condition D.4 of the Order for Monticello Nuclear Generating Plant (MNGP).

MNGP has designed and installed a venting system that provides venting capability from the wetwell during severe accident conditions in response to Phase 1 of NRC Order EA-13-109. MNGP has implemented a reliable containment venting strategy that makes it unlikely that the plant would need to vent from the containment drywell before alternative reliable containment heat removal and pressure control is reestablished in response to Phase 2 of NRC Order EA-13-109. The information provided herein documents full compliance for MNGP with NRC Order EA-13-109.

MNGP Phases 1 and 2 OIP Open Items and ISE Open Items have been addressed and reviewed by the NRC as documented in Reference 18 and as provided below, and are considered complete.

1. Follow industry guidance on missile protection for HCVS.

2. Identify the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> power supply for the HCVS.

Closed - see ISE Phase 1 Open Item 5 Closed - see ISE Phase 1 Open Item 1

3. Determine radiological conditions for the FLEX portable equipment Closed - see staging areas.

ISE Phase 1 Open Item 3 Page 5 of 13

L-MT-19-020

4. Evaluate the Alternate Shutdown System (ASDS) panel and Backup HCVS Operation Station locations for accessibility, habitability, staffing sufficiency, associated pathways from the control room and communication capability with vent-use decision makers.

5. Determine approach or combination of approaches to control hydrogen.

6. Determine the Qualification Method for HCVS instrumentation.

7. Evaluate the effects of radiological and temperature constraints on the deployment of nitrogen bottles after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

8. Evaluate HCVS battery charger location for accessibility, habitability, staffing sufficiency, associated pathways from control room and communication capability with vent-use decision makers.

1. Determine approach to repower Low Pressure Coolant Injection (LPCI) swing bus from FLEX PDG.

1. Make available for NRG staff audit the final sizing evaluation for HCVS batteries/battery charger including incorporation into FLEX Diesel Generator (DG) loading calculation.

2. Make available for NRG staff audit documentation of the HCVS nitrogen pneumatic system design including sizing and location.

3. Make available for NRG staff audit an evaluation of temperature and radiological conditions to ensure that operating personnel can safely access and operate controls and support equipment.

Page 6 of 13 Closed -see ISE Phase 1 Open Items 3 and 7 Closed-see ISE Phase 1 Open Items 8 and 9 Closed-see ISE Phase 1 Open Item 10 Closed -see ISE Phase 1 Open Item 3 Closed - see ISE Phase 1 Open Items 3 and 7 Complete See Reference 16 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18

L-MT-19-020

4. Make available for NRC staff audit analyses demonstrating that HCVS has the capacity to vent the steam/energy equivalent of one percent of licensed/rated thermal power (unless a lower value is justified), and that the suppression pool and the HCVS together are able to absorb and reject decay heat, such that following a reactor shutdown from full power containment pressure is restored and then maintained below the primary containment design pressure and the primary containment pressure limit.

5. Make available for NRC staff audit the seismic and tornado missile final design criteria for the HCVS stack.

6. Make available for NRC staff audit the descriptions of local conditions (temperature, radiation and humidity) anticipated during Extended Loss of AC Power (ELAP) and severe accident for the components (valves, instrumentation, sensors, transmitters, indicators, electronics, control devices, etc.) required for HCVS venting including confirmation that the components are capable of performing their functions during ELAP and severe accident conditions.

7. Make available for NRC staff audit documentation that demonstrates adequate communication between the remote HCVS operation locations and HCVS decision makers during ELAP and severe accident conditions.

8. Provide a description of the final design of the HCVS to address hydrogen detonation and deflagration.

9. Provide a description of the strategies for hydrogen control that minimizes the potential for hydrogen gas migration and ingress into the reactor building or other buildings.

10. Make available for NRC staff audit descriptions of all instrumentation and controls (existing and planned) necessary to implement this order including qualification methods.

Page 7 of 13 Closed See Reference 18 Closed See Reference 18 and Additional Information in of Reference 20 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18

L-MT-19-020

11. Make available for NRG staff audit documentation of an evaluation verifying the existing containment isolation valves, relied upon for the HCVS, will open under the maximum expected differential pressure during Beyond Design Basis External Event (BDBEE) and severe accident wetwell venting.

1. Licensee to provide the plant specific justification for SAWA

[Severe Accident Water Addition] flow capacity less than specified in the guidance in NEI 13-02, Section 4.1.1.2.

2. Licensee to evaluate the SAWA equipment and controls, as well as the ingress and egress paths for the expected severe accident conditions (temperature, humidity, radiation) for the sustained operating period.

3. Licensee to demonstrate how instrumentation and equipment being used for SAWA and supporting equipment is capable to perform for the sustained operating period under the expected temperature and radiological conditions.

4. Licensee to demonstrate that containment failure as a result of overpressure can be prevented without a drywell vent during severe accident conditions.

5. Licensee to demonstrate how the plant is bounded by the reference plant analysis that shows the SAWM [Severe Accident Water Management] strategy is successful in making it unlikely that a drywell vent is needed.

6. Licensee to demonstrate that there is adequate communication between the MGR [Main Control Room] and the Intake Structure operator at the FLEX manual valve during severe accident conditions.

7. Licensee to demonstrate the SAWM flow instrumentation qualification for the expected environmental conditions.

Page 8 of 13 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18 Closed See Reference 18

L-MT-19-020 Milestone Schedule - Items Complete Submit 6 Month Updates:

Update 1 Update 2 Update 3 (with Phase 2 OIP)

Update 4 Update 5 Update 6 Update 7 Update 8 Update 9 Phase 1 Modifications:

Hold preliminary/conceptual design meeting Design Engineering On-site/Complete Implementation Outage Walk Through Demonstration/Functional Test Phase 1 Procedure Changes Active:

Operations Procedure Changes Developed Site Specific Maintenance Procedure Developed Page 9 of 13 June 2014 December 2014 June 2015 December 2015 June 2016 December 2016 June 2017 December 2017 June 2018 December 2018 June 2014 November 2016 May 2017 May 2017 May 2017 May 2017

L-MT-19-020 Procedure Changes Active Phase 1 Training:

Training Complete Phase 1 Completion:

HCVS Implementation Phase 2 Modifications:

Hold preliminary/conceptual design meeting Design Engineering On-site/Complete Implementation Outage Walk Through Demonstration/Functional Test Phase 2 Procedure Changes Active:

Operations Procedure Changes Developed Site Specific Maintenance Procedure Developed Procedure Changes Active Phase 2 Training:

Training Complete Phase 2 Completion:

HCVS Implementation Submit Completion Report Page 10 of 13 May 2017 May 2017 May 2017 October 2015 June 2018 Not Needed December 2018 December 2018 March 2019 February 2019 May 2018 April 2019 April 2019, completed with this submittal

L-MT-19-020 Order EA-13-109 Compliance Elements Summary The elements identified below for MNGP as well as the Phase 1 (Updated) and Phase 2 OIP response submittal (Reference 10), and the 6-Month Status Reports (References 6, 7, 11, 14, 15, 16, 19, and 20), demonstrate compliance with NRG Order EA-13-109.

The MNGP Final Integrated Plan for reliable hardened containment vent Phase 1 and Phase 2 strategies is provided in the enclosure to this letter.

HCVS Phase 1 and Phase 2 Functional Requirements and Design Features -

Complete The MNGP Phase 1 HCVS provides a vent path from the wetwell to remove decay heat, vent the containment atmosphere, and control containment pressure within acceptable limits. The Phase 1 HCVS will function for those accident conditions for which containment venting is relied upon to reduce the probability of containment failure, including accident sequences that result in the loss of active containment heat removal capability during an extended loss of alternating current power.

The MNGP Phase 2 HCVS provides a reliable containment venting strategy that makes it unlikely that the plant would need to vent from the containment drywell before alternative reliable containment heat removal and pressure control is reestablished. The MNGP Phase 2 HCVS strategies implement Severe Accident Water Addition (SAWA) with Severe Accident Water Management (SAWM) as an alternative venting strategy. This strategy consists of the use of the Phase 1 wetwell vent and SAWA hardware to implement a water management strategy that will preserve the wetwell vent path until alternate reliable containment heat removal can be established.

The MNGP Phase 1 and Phase 2 HCVS strategies are in compliance with Order EA-13-109. The modifications required to support the HCVS strategies for MNGP have been fully implemented in accordance with the station processes.

HCVS Phase 1 and Phase 2 Quality Standards - Complete The design and operational considerations of the Phase 1 and Phase 2 HCVS installed at MNGP comply with the requirements specified in the Order and described in NEI 13-02, Revision 1, "Industry Guidance for Compliance with Order EA-13-109". The Phase 1 and Phase 2 HCVS has been installed in accordance with the station design control process.

The Phase 1 and Phase 2 HCVS components including piping, piping supports, containment isolation valves, containment isolation valve actuators, and containment isolation valve position indication have been designed consistent with the design basis of the plant. All other Phase 1 and Phase 2 HCVS Page 11 of 13

L-MT-19-020 components including electrical power supply, valve actuator pneumatic supply and instrumentation have been designed for reliable and rugged performance that is capable of ensuring Phase 1 and Phase 2 HCVS functionality following a seismic event.

HCVS Phase 1 and Phase 2 Programmatic Features - Complete Storage of portable equipment for MNGP Phase 1 and Phase 2 HCVS use provides adequate protection from applicable site hazards, and identified paths and deployment areas will be accessible during all modes of operation and during severe accidents, as recommended in NEI 13-02, Revision 1, Section 6.1.2.

Training in the use of the Phase 1 and Phase 2 HCVS for MNGP has been completed in accordance with an accepted training process i:ts recommended in NEI 13-02, Revision 1, Section 6.1.3.

Operating and maintenance procedures for MNGP have been developed and integrated with existing procedures to ensure safe operation of the Phase 1 and Phase 2 HCVS. Procedures have been verified and are available for use in accordance with the site procedure control program.

Site processes have been established to ensure the Phase 1 and Phase 2 HCVS is tested and maintained as recommended in NEI 13-02, Revision 1, Sections 5.4 and 6.2.

MNGP has completed validation in accordance with industry developed guidance to assure required tasks, manual actions, and decisions for HCVS strategies are feasible and may be executed within the constraints identified in the HCVS Phases 1 and 2 OIP for Order EA-13-109 (Reference 10).

MNGP has completed evaluations to confirm accessibility, habitability, staffing sufficiency, and communication capability in accordance with NEI 13-02, Revision 1, Sections 4.2.2 and 4.2.3.

Please contact Stephen Sollom, Senior Regulatory Affairs Engineer, at 612-342-8982, if additional information or clarification is required.

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L-MT-19-020 Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on April l.i_, 2019.

ristopher R. Church Site Vice President, Monticello Nuclear Generating Plant Northern States Power Company - Minnesota Enclosure (1) cc:

Administrator, Region Ill, USNRC Project Manager, Monticello Nuclear Generating Plant, USNRC Resident Inspector, Monticello Nuclear Generating Plant, USNRC Page 13 of 13