Text

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 EA-13-109) Including Phase 1..
	ML15356A120
Person / Time
Site:	Monticello
Issue date:	12/17/2015
From:	Gardner P; Northern States Power Co, Xcel Energy
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	EA-13-109, L-MT-15-090
	Download: ML15356A120 (78)
	v • d • e

X ceIEnegy@Monticello, MNuclear5,5362Generating PlantCu*,o07 Xcel~Monteello December 17, 2015 L-MT-1 5-090 10 CFR 2.202 EA-1 3-109 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket No. 50-263 Renewed Facility Operating License No. DPR-22 Monticello Nuclear Generatingq Plant's Phase 2 Overall Inteqrated Plan in Response to June 6, 2013 Commission Order Modifyingq Licenses with Reqard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109) includinq Phase 1 Status Report

References:

1) NRC Order Number EA-1 3-1 09, "Issuance of Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," dated June 6, 2013. (ADAMS Accession Number ML13143A334)

2) NRC Interim Staff Guidance JLD-ISG-201 5-01, "Compliance with Phase 2 of Order EA-1 3-1 09, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated April 2015. (ADAMS Accession Number ML15104A118)

3) Nuclear Energy Institute (NEI) 13-02, "Industry Guidance for Compliance with Order EA-13-109," Revision 1, dated April 2015.

(ADAMS Accession Number ML15113B318)

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

"MNGP's Phase I 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-1 3-1 09),"

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

Document Control Desk Page 2

5) Letter from K. Fill (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-1 3-1 09)," L-MT-14-092, dated December 16, 2014. (ADAMS Accession No. ML14353A215)

6) 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-13-1 09), Phase 1," L-MT-15-031, dated June 22, 2015.

(ADAMS Accession No. ML15173A176)

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

d/b/a Xcel Energy. Reference 1 was immediately effective and directs NSPM to require the MNGP, a Boiling Water Reactor (BWR) with a Mark I containment, to implement a reliable, severe accident capable hardened containment venting system (HCVS). This requirement will be implemented in two phases. Specific requirements for both phases of the Order are outlined in Attachment 2 of Reference 1.

Reference 1 requires submission of an overall integrated plan (OIP) for Phase 2, including a description of how compliance with the Phase 2 requirements, described in of Reference 1, will be achieved by startup from the first refueling outage that begins after June 30, 2017, or June 30, 2019, whichever comes first. This letter provides the OIP for Phase 2 pursuant to Section IV, Condition D.2, of Reference 1.

The NRC's interim staff guidance (Reference 2) for Phase 2 of the Order was issued April 2015, which endorsed, with exceptions and clarifications, the methodologies described in the industry guidance document NEI 13-02, Revision 1(Reference 3).

Section 7 of NEI 13-02, Revision 1 (Reference 3) contains the specific reporting requirements for the Phase 20OIP.

The purpose of this letter is to provide the OIP for Phase 2 of the Order. The OIP is based on conceptual design information. Final design details and associated procedure guidance, as well as any revisions to the information contained in the Enclosure, will be provided in the six-month status reports required by Reference 1. The information in the Enclosure to this letter aligns with the guidance provided in NEI 13-02, Revision 1, Section 7.

In addition, a status report of Phase 1 activities is included within the Phase 20OIP. The Phase 10OIP was provided to the NRC in Reference 4. Status reports for Phase 1 were previously provided to the NRC in References 5 and 6. The current status report for

Document Control Desk Page 3 Phase 1 s incorporated throughout the Phase 20OIP as the Enclosure incorporates both Phase 1 and Phase 20GIP information. Changes to the Phase 10OIP are indicated in of the Enclosure to assist the NRC in determining the scope of changes that have been made. Any significant changes to this plan will be communicated to the NRC staff in future Six-Month Status Reports.

Please contact John Fields, Fukushima Response Licensing, at 763-271-6707, if additional information or clarification is required.

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 December 1+/-" 2015.

Peter A. Gardner Site Vice President, onicello Nuclear Generating Plant Northern States Poeompany - Minnesota Enclosure cc: Administrator, Region Ill, USNRC Project Manager, Monticello Nuclear Generating Plant, USNRC Resident Inspector, Monticello Nuclear Generating Plant, USNRC

L-MT-1 5-090 Enclosure ENCLOSURE MONTICELLO NUCLEAR GENERATING PLANT HARDENED CONTAINMENT VENTING SYSTEM (HCVS)

PHASE 2 OVERALL INTEGRATED PLAN Table of Contents:

Part 1: General Integrated Plan Elements and Assumptions Part 2: Boundary Conditions for Wetwell Vent Part 3: Boundary Conditions for EA-1 3-1 09, Option B.2 Part 3.1 Boundary Conditions for SAWA Part 3.IA Boundary Conditions for SAWA/SAWM Part 3.1 B Boundary Conditions for SAWA/SADV Part 4: Programmatic Controls, Training, Drills and Maintenance Part 5: Implementation Schedule Milestones : HCVS/SAWA Portable Equipment A: Sequence of Events HCVS .1 .A"Sequence of Events Timeline - SAWA / SAWM .1.B: Sequence of Events Timeline - SADV .1.C: SAWA!/ SAWM Plant-Specific Datum .1.D: SAWM SAMG Approved Language : Conceptual Sketches : Failure Evaluation Table : References : Changes/Updates to this Overall Integrated Implementation Plan : List of Overall Integrated Plan Open Items Page 1 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Introduction In 1989, the NRC issued Generic Letter 89-16, "Installation of a Hardened Wetwell Vent," to all licensees of Boiling Water Reactors (BWRs) with Mark I containments to encourage licensees to voluntarily install a hardened wetwell vent. In response, licensees installed a hardened vent pipe from the suppression pool to some point outside the secondary containment envelope (usually outside the reactor building).

Some licensees also installed a hardened vent branch line from the drywell (DW).

On March 19, 2013, the Nuclear Regulatory Commission (NRC) Commissioners directed the staff per Staff Requirements Memorandum (SRM) for SECY-12-0157 to require licensees with Mark I and Mark II containments to "upgrade or replace the reliable hardened vents required by Order EA-12-050 with a containment venting system designed and installed to remain functional during severe accident conditions."

In response, the NRC issued Order EA-1 3-1 09, Issuance of Order to Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accidents, dated June 6, 2013. The Order (EA-1 3-109) requires that licensees of BWR facilities with Mark I and Mark II containment designs ensure that these facilities have a reliable hardened vent to remove decay heat from the containment and maintain control of containment pressure within acceptable limits following events that result in the loss of active containment heat removal capability, while also maintaining the capability to operate under severe accident (SA) conditions resulting from an Extended Loss of AC Power (ELAP).

The Order requirements are applied in a phased approach where:

"Phase 1 involves upgrading the venting capabilities from the containment wetwell to provide reliable, severe accident capable hardened vents to assist in preventing core damage and, if necessary, to provide venting capability during severe accident conditions." (Completed "no later than startup from the second refueling outage that begins after June 30, 2014, or June 30, 2018, whichever comes first.")

"Phase 2 involves providing additional protections for severe accident conditions through installation of a reliable, severe accident capable DW vent system or the development of a reliable containment venting strategy that makes it unlikely that a licensee would need to vent from the containment DW during severe accident conditions." (Completed "no later than startup from the first refueling outage that begins after June 30, 2017, or June 30, 2019, whichever comes first.")

The NRC provided an acceptable approach for complying with Order EA-1 3-1 09 through Interim Staff Guidance (ISG) (JLD-ISG-2013-02 issued in November 2013 and JLD-ISG-2015-01 issued in April 2015). The ISG endorses the compliance approach presented in NEI 13-02, Revisions 0 and 1, Industry Guidance for Compliance with Order EA-13-1 09, BWR Mark I & II Reliable Hardened Containment Vents Capable of Operation Under Sever Accident Conditions, with clarifications. Except in those cases in Page 2 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan which a licensee proposes an acceptable alternative method for complying with Order EA-1 3-1 09, the NRC staff will use the methods described in the ISGs to evaluate licensee compliance as presented in submittals required in Order EA-1 3-1 09.

The Order also requires submittal of an overall integrated plan (OIP), which will provide a description of how the requirements of the Order will be achieved. This document provides the OIP for complying with Order EA-1 3-1 09 using the methods described in NEI 13-02 and endorsed by NRC JLD-ISG-2013-02 and JLD-ISG-2015-01. Six-month progress reports will be provided consistent with the requirements of Order EA1 3-109.

The submittals required are:

OIP for Phase 1 of EA-1 3-1 09 was required to be submitted by licensees to the NRC by June 30, 2014. The NRC requires periodic (six-month) updates for the Hardened Containment Vent System (HCVS) actions being taken. The first update for Phase 1 was due December 2014, with the second due June 2015.

OIP for Phase 2 of EA-1 3-1 09 is required to be submitted by licensees to the NRC by December 31, 2015. It is expected the December 2015 six month update for Phase 1 will be combined with the Phase 20OIP submittal by means of a combined Phase 1 and 20OIP.

Thereafter, the six-month updates will be for both the Phase 1 and Phase 2 actions until complete, consistent with the requirements of Order EA-1 3-109.

Note: At the Licensee's option, the December 2015 six-month update for Phase 1 may be independent of the Phase 20QIP submittal, but will require separate six-month updates for Phase 1 and 2 until each phase is in compliance.

The plant venting actions for the EA-1 3-109, Phase 1, severe accident capable venting scenario can be summarized by the following:

The HCVS will be initiated via manual action from either the Main Control Room (MCR) (some plants have a designated Primary Operating Station (POS) that will be treated as the main operating location for this order) or from a Remote Operating Station (ROS) at the appropriate time based on procedural guidance in response to plant conditions from observed or derived symptoms.

The vent will utilize containment parameters of pressure and level from the MCR instrumentation to monitor effectiveness of the venting actions.

The vent operation will be monitored by HCVS valve position, temperature, and effluent radiation levels.

The HCVS motive force will be monitored and have the capacity to operate for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months with installed equipment. Replenishment of the motive force will be by use of portable equipment once the installed motive force is exhausted.

Venting actions will be capable of being maintained for a sustained period of up to 7 days or a shorter time if justified.

Page 3 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan The NRC issued an Interim Staff Evaluation (ISE) for Phase I of the Monticello Nuclear Generating Plant (MNGP) HCVS Order response on April 2, 2015.

The Phase 2 actions can be summarized as follows:

Utilization of Severe Accident Water Addition (SAWA) to initially inject water into the Reactor Pressure Vessel (RPV) or DW.

Utilization of Severe Accident Water Management (SAWM) to control injection and Suppression Pool level to ensure the HCVS (Phase 1) wetwell vent (SAWV) will remain functional for the removal of decay heat from containment.

Ensure that the decay heat can be removed from the containment for seven (7) days using the HCVS or describe the alternate method(s) to remove decay heat from the containment from the time the HCVS is no longer functional until alternate means of decay heat removal are established that make it unlikely the DW vent will be required for DW pressure control.

The SAWA and SAWM actions will be manually activated and controlled from areas that are accessible during severe accident conditions.

Parameters measured should be DW pressure, Suppression Pool level, SAWA flowrate and the HCVS parameters listed above.

Alternatively, SAWA and a Severe Accident Capable Drywell Vent (SADV) strategy may be implemented to meet Phase 2 of Order EA-1 3-109.

Page 4 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 1: General Integrated Plan Elements and Assumptions Include a description of any alternatives to the guidance. A technicaljustifcation and basisfor the alternative needs to be provided This will likely require a pre-meeting with the NRC to review the alternative.

IRef: JLD-ISG-2013-02, JLD-ISG-2015-O1 Compliance will be attained for MNGP with no known deviations to the guidelines in JLD-ISG-2013-02, JLD-ISG-2015-01 and NEI 13-02 for each phase as follows:

The HCVS will be comprised of installed and portable equipment and operating guidance:

Severe Accident Wetwell Vent (SAWV) - Permanently installed vent from the Suppression Pool to the top of the reactor building.

Severe Accident Water Addition (SAWA) - A combination of permanently installed and portable equipment to provide a means to add water to the reactor pressure vessel (RPV) following a severe accident and monitor system and plant conditions.

Severe Accident Water Management (SAWM) strategies and guidance for controlling the water addition to the RPV for the sustained operating period. (reference attachment 2.1.D)

Phase 1 (wetwell): by the startup from the second refueling outage that begins after June 30, 2014, or June 30, 2018, whichever comes first. Currently scheduled for May 2017.

Phase 2 (alternate strategy): by the startup from the first refueling outage that begins after June 30, 2017 or June 30, 2019, whichever comes first. Currently scheduled for May 2019.

Northern States Power Minnesota, a Minnesota corporation, doing business as Xcel Energy (NSPM -

the licensee for MNGP) has identified two alternatives from the guidance in JLD-ISG-2013-02 and NEI 13-02, which is described in the following paragraphs.

1) HCVS Design Temperature NEI 13-02, Section 2.4.3.3 (Reference 11) states:

The design temperature for the wetwell vent portions of the HCVS are recommended to be based on the 3500 F upper bound of the EPG/SAG [Emergency Procedure Guidelines/Severe Accident Guidelines] bases document which is above the saturation temperature correspondingto typical PCPL [Primary Containment Pressure Limit] values.

The design pressure and temperature for the existing MNGP Hardened Containment Vent System (called Hard Pipe Vent System) are 62 psi9 and 309°F, respectively. The design temperature of 309°F is lower than the NEI 13-02 recommended value of 350°F, but is acceptable for the MNGP Page 5 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 1: General Integrated Plan Elements and Assumptions HCVS design for the following reasons:

NEI 13-02, Section 2.4.3.1 states:

The suppression pool/wetwell of a BWR Mark 1/Il containment can be considered to be at saturation conditions. MNGP is designed with a Mark I containment with a design pressure of 62 psig. At saturation conditions, this corresponds to a saturation temperature of 309°F. Thus, the HCVS design temperature of 309°F meets the requirements of NE1-13-02, Section 2.4.3.1. To reach 350°F in the HCVS, the MNGP wetwell would need to be at 120 psig, which exceeds the design of the MNGP primary containment design pressure of 62 psig.

Procedural guidance will direct venting containment through the HCVS prior to primary containment pressure exceeding 62 psig.

2) HCVS Release Location NEI 13-02, Section 4.1.5.2.2 (Reference 11), states:

The release point should be situated away from ventilation system intake and exhaust openings or other openings that may be used as naturalcirculation ventilation in take flow paths during a BDBEE (e.g., to prevent recirculationof the releases back into the buildings.)

The existing Hardened Vent System discharge path is currently routed next to the Reactor Building plenum exhaust with the vent exhaust 3 feet (ft) above the top of the Reactor Building plenum exhaust stack (see Figure 1). The vent exhaust is above the main plant structures. The vent is located greater than 100 ft above ground level, providing an elevated release point that will not affect personnel staging any portable equipment needed for the Beyond Design Basis External Event (BDBEE). (OIP Open Item 3)

Page 6 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 1: General Integlrated Plan Elements and Assumptions Figure 1: HCVS Exhaust Vent Side View

"* :7Top View Reactor Building Plenum.,

"- "Reactor BuildingS Reactor Building Plenum Exhaust fans --

Reactor Building Roof The HCVS exhaust vent is not near the Reactor Building intake, control room intake, or the emergency response facilities, but is next to the Reactor Building plenum exhaust path. The Reactor Building plenum exhaust fans will be without a power source in a station blackout.

There are two dampers after each Reactor Building plenum exhaust fan - a backdraft damper and discharge damper. The discharge damper will close on loss of power associated with the station blackout and the backdraft damper will close on loss of Reactor Building exhaust flow. Both dampers are designed to prevent reverse flow, and therefore, prevent HCVS gases from entering the Reactor Building via the plenum room. Safety-related dampers also isolate the plenum room from the rest of the Reactor Building. The "T" at the top of the vent will also be removed and replaced with a straight exit with a weather cap. This change will direct the vented gases upward and away from the plant.

Therefore, the existing HCVS configuration is an acceptable alternative to JLD-ISG-1 3-02 and NEl 13-02.

If additional deviations are identified, the deviations will be communicated in a future six-month Page 7 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 1: General Integrated Plan Elements and Assumptions status report following identification.

List resultantdetermination of screened in hazardsfrom the EA-12-049 Compliance.

Ref: NEI 13-02 Section 5.2.3 and D.1.2 The following extreme external hazards screen-in for MNGP:

o Seismic, External Flooding, Extreme Cold, High Wind, Extreme High Temperature The following extreme external hazards screen out for MNGP:

None Key Site assumptio*ns toimplement NEI 13-02 HCVSPhase anid 2 Act6ioS.!j Provide key assumptions associatedwith implementation of HCVS Phase 1 and Phase 2 Actions Ref: NEI 13-02, Revision 1, Section 2, NEI 12-06 Revision 0 Mark I/Il Generic EA-1 3-1 09 Phase 1 and Phase 2 Related Assumptions:

Applicable EA-12-049 assumptions:

049-1. Assumed initial plant conditions are as identified in NEI 12-06, Section 3.2.1.2, Items 1 and 2.

049-2. Assumed initial conditions are as identified in NEI 12-06, Section 3.2.1.3, Items 1, 2, 4, 5, 6 and 8.

049-3. Assumed reactor transient boundary conditions are as identified in NEI 12-06, Section 3.2.1.4, Items 1, 2, 3 and 4.

049-4. No additional events or failures are assumed to occur immediately prior to or during the event, including security events, except for failure of Reactor Core Isolation Cooling (RC IC) or High Pressure Coolant Injection (HPCI) systems. (Reference NEI 12-06, Section 3.2.1.3, Item 9) 049-5. At Time-0 the event is initiated and all rods insert and no other event beyond a common site ELAP is occurring at any or all of the units. (Reference NEI 12-06, Section 3.2.1.3, Item 9 Page 8 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 1: General Integqrated Plan Elements and Assumptions and Section 3.2.1.4, item 1-4) 049-6. At 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , an ELAP is declared and actions begin as defined in EA-12-049.

049-7. DC power and distribution can be credited for the duration determined per the EA-12-049 (FLEX) methodology for battery usage, i.e. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This assumption applies to the water addition capability under SAWAISAWM. The power supply scheme for the HCVS shall be in accordance with EA-1 3-1 09 and the applicable guidance. (Reference NEI 12-06, Section 3.2.1.3, Item 8.)

049-8. Deployment resources are assumed to begin arriving at hour 6 and fully staffed by 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

049-9. All activities associated with plant specific FLEX strategies that are not specific to implementation of the HCVS, including such items as debris removal, communication, notification, Spent Fuel Pool (SFP) level and makeup, security response, opening doors for cooling, and initiating conditions for the event, can be credited as previously evaluated for FLEX. (Refer to assumption 109-02 below for clarity on SAWA and HCVS-FAQ-1 1)

Applicable EA-1 3-1 09 .qeneric assumptions:

109-01. Site response activities associated with EA-13-109 actions are considered to have no access limitations associated with radiological impacts while RPV level is above 2/3 core height (core damage is not expected). This is further addressed in HCVS-FAQ-12.

109-02. Portable equipment can supplement the installed equipment after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months provided the portable equipment credited meets the criteria applicable to the HCVS. An example is use of FLEX portable air supply equipment that is credited to recharge air lines for HCVS components after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The FLEX portable air supply used must be demonstrated to meet the "SA Capable" criteria that are defined in NEI 13-02, Section 4.2.4.2, and Appendix D, Section D. 1.3. This assumption does not apply to Phase 2 SAWAISAWM because SAWA equipment needs to be connected and placed in service within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months from the time of the loss of RPV injection. (Reference HCVS-FAQ-12) 109-03. SFP level is maintained with either on-site or off-site resources such that the SFP does not contribute to the analyzed source term. (Reference HCVS-FAQ-07) 109-04. Existing containment components design and testing values are governed by existing plant primary containment criteria (e.g., Appendix J) and are not subject to the testing criteria from NEI 13-02. (Reference HCVS-FAQ-05 and NEI 13-02 section 6.2.2) 109-05. Classical design basis evaluations and assumptions are not required when assessing the operation of the HCVS. The reason this is not required is that the Order postulates an unsuccessful mitigation of an event such that an ELAP progresses to a severe accident with ex-vessel core debris which classical design basis evaluations are intended to prevent.

(Reference NEI 13-02, Section 2.3.1)

Page 9 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 1: General Integrated Plan Elements and Assumptions 109-06. HCVS manual actions that require minimal operator steps and can be performed in the postulated thermal and radiological environment at the location of the step(s) (e.g., load stripping, control switch manipulation, aligning nitrogen bottles) are acceptable to obtain HCVS venting dedicated functionality. (Reference HCVS-FAQ-01) This assumption does not apply to Phase 2 SAWA/SAWM because SAWA equipment needs to be connected and placed in service within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months from the time of the loss of RPV injection and will require more than minimal operator action.

109-07. HCVS dedicated equipment is defined as vent process elements that are required for the HCVS to function in an ELAP event that progresses to core melt ex-vessel. (Reference HCVS-FAQ-02 and HCVS-WP-01). This assumption does not apply to Phase 2 SAWAISAWM because SAWA equipment is not dedicated to HCVS but shared to support FLEX functions. This is further addressed in HCVS-FAQ-1 1.

109-08. Use of MAAP Version 4 or higher provides adequate assurance of the plant conditions (e.g.,

RPV water level, temperatures, etc.) assumed for Order EA-1 3-109 BDBEE and SA HCVS operation. (Reference FLEX MAAP Endorsement ML13190A201) Additional analysis using RELAP5/MOD 3, GOTHIC, PCFLUD, LOCADOSE and SHIELD are acceptable methods for evaluating environmental conditions in areas of the plant provided the specific version utilized is documented in the analysis. MAAP Version 5 was used to develop EPRI Technical Report 3002003301 to support DW temperature response to SAWA under severe accident conditions.

109-09. NRC Published Accident Evaluations (e.g. SOARCA, SECY-12-0157, and NUREG 1465) as related to Order EA-1 3-1 09 conditions are acceptable as references. (Reference NEI 13-02 section 8).

109-1 0. Permanent modifications installed or planned per Order EA-12-049 are assumed implemented and may be credited for use in EA-1 3-1 09 Order response.

109-11. This Overall Integrated Plan is based on Emergency Operating Procedure (EOP) changes consistent with EPG/SAGs, Revision 3, as incorporated per the sites EOP/ Severe Accident Management Guidelines (SAMG) procedure change process. This assumption does not apply to Phase 2 SAWM because SAWM is not part of Revision 3. (Reference Attachment 2.1 .D for SAWM SAMG Changes approved by the BWROG Emergency Procedures Committee) 109-12. Under the postulated scenarios of Order EA-1 3-1 09, the Control Room is adequately protected from excessive radiation dose due to its distance and shielding from the reactor (per General Design Criterion (GDC) 19 in 10CFR50, Appendix A) and no further evaluation of its use as the preferred HCVS control location is required provided that the HCVS routing is a sufficient distance away from the MCR or is shielded to minimize impact to the MCR dose. In addition, adequate protective clothing and respiratory protection are available if required to address contamination issues. (Reference HCVS-FAQ-01 and HCVS-FAQ-09)

Page 10 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 1: General Integqrated Plan Elements and Assumptions 109-13. The suppression pool/wetwell of a BWR Mark I/Il containment is considered to be bounded by assuming a saturated environment for the duration of the event response because of the water/steam interactions.

109-14. RPV depressurization is directed by the EPGs in all cases prior to entry into the SAGs.

(Reference NEl 13-02 Rev 1, Section 1.1.3) 109-15. The Severe Accident impacts are assumed on one unit only due to the site compliance with NRC Order EA-12-049. However, each BWR Mark I and II under the assumptions of NRC Order EA-1 3-109 ensures the capability to protect the containment exists for each unit.

(HCVS-FAQ-1 0) This is further addressed in HCVS-FAQ-1 0.

Plant Specific HCVS Related Assumptions/Characteristics:

PLT-1. ASDS Panel Rather than the MCR, NSPM will use the Alternate Shutdown System (ASDS) panel located in the Emergency Filtration Train (EFT) Building as the primary control station for operation and monitoring of the HCVS, as permitted by Order EA-1 3-109, Section 1.2.4.

PLT-2. Backup HCVS Operating Station If operation of the HCVS is not possible from the ASDS panel, the HCVS will be operated manually from the Turbine Building, in a location to be determined. This location will be called the Backup HCVS Operating Station.

PLT-3. Initiation of Venting The HCVS will not be opened at a specific time. Use of the HCVS will be determined by plant conditions and procedural guidance.

Page 11 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Provide a sequence of events and identify any time or environmental constraint required for success including the basis for the constraint. *'* *..

HCVS Actions that have a time constraint to be successful should be identifed with a technical basis and a justification provided that the time can reasonably be met (for example, action to open vent valves).

HCVS Actions that have an environmental constraint (e.g. actions in areas of High Thermal stress or High Dose areas) should be evaluatedper guidance.

Describe in detail in this section the technical basisfor the constraints identified on the sequence of events timeline attachment.

See attachedsequence of events timeline (Attachment 2A)

Ref: EA-13-109 Section 1.1.1, 1.1.2, 1.1.3 /1NEI13-02 Section 4.2.5, 4.2.6. 6.1.1 The operation of the HCVS will be designed to minimize the reliance on operator actions in response to hazards listed in Part 1. Initial operator actions will be completed by plant personnel and will include the capability for remote-manual initiation from the HCVS control station. A list of the remote manual actions performed by plant personnel to open the HCVS vent path can be found in the following table (2-1). A Failure Evaluation Table, which shows alternate actions that can be performed, is included in Attachment 4.

Table 2-1 - HCVS Remote Manual Actions Primary Action Primary Location / Notes Component

1. OPEN manual isolation valve Backup HCVS Operating Current pneumatic supply is from to connect HCVS to Station / Component number Alternate Nitrogen System. An dedicated HCVS N2 will be determined as part of independent, dedicated N2 supply (nitrogen) supply modification to install will be installed to meet Phase 1 of dedicated HCVS N2 supply. EA-1 3-1 09

2. OPEN manual isolation valve Backup HCVS Operating Current supply is from the Alternate to connect rupture disk to Station I Component number Nitrogen System. An independent, dedicated rupture disk N2 will be determined as part of dedicated N2 supply will be supply modification to install installed to meet Phase 1 of dedicated rupture disk N2 EA-1 3-1 09.

supply

3. Breach the rupture disk by ASDS Panel/IKey-locked If required - Rupture disk will burst opening solenoid valve switch HS-4541 between 44 - 50 psig. Alternate method by using manual valve at Backup HCVS Operating Station.

Page 12 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent

4. Open air operated ASDS panel / Key-locked Alternate method by using manual suppression pooi Primary switches HS-4539 and HS- valves at Backup HCVS Operating Containment Isolation Valves 4540 Station.

(PCIVs) AO-4539 and AO-4540

5. Transfer HCVS power to Y80 distribution panel is Transfer occurs prior to depletion of uninterruptable power supply located near the ASDS dedicated HCVS battery. Actions (UPS) Y80, powered from panel. will be required to transfer power at EA-12-049 FLEX portable a time greater than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

diesel generator (PDG)

6. Replenish pneumatics with Nitrogen bottles will be Prior to depletion of the pneumatic replaceable N2 bottles located in an area that is sources, actions will be required to accessible to operators, connect back-up sources at a time preferably near the Backup greater than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

HCVS Operating Station.

Provide a sequencethe succe~ssincluding of basis eventsforand theidentifY any time or environmental constraint. *: constraint

'i

, required for A timeline was developed to identify required operator response times and potential environmental constraints. This timeline is based upon the following three cases:

1. Case 1 is a based upon the action response times developed for FLEX when utilizing anticipatory venting in a BDBEE without core damage.

2. Case 2 is based on a SECY-12-0157 long term station blackout (LTSBO) (or ELAP) with failure of ROIC after a black start where failure occurs because of subjectively assuming over injection.

3. Case 3 is based on NUREG-1 935 (SOARCA) results for a prolonged SBO (or ELAP) with the loss of RCIC case without black start.

The followincq is a discussion of time constraints identified in Attachment 2A for the 3 timeline cases identified above

,, Initiate use of HCVS per site procedures to maintain containment parameters below design limits and within the limits that allow continued use of RCIC. The reliable operation of HCVS will be met because HCVS meets the seismic requirements identified in NEI 13-02 and will be powered by Direct Current (DC) buses with motive force supplied to HCVS valves from a dedicated installed HCVS N2 supply. Critical HCVS controls and instruments associated with containment will be DC powered and operated from the ASDS panel or a Remote Operating Station. The DC power for HCVS will be available as long as the HCVS is required. The HCVS battery will supply HCVS critical components / instruments during the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . In addition, when available, Phase 2 FLEX PDG can provide power before battery life is Page 13 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent exhausted. HCVS operation will occur from the ASDS panel.

Installed, dedicated nitrogen bottles will be able to burst the rupture disk if needed. In addition, installed, dedicated nitrogen bottles will be able to supply the HCVS for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

The HCVS Nitrogen bottles will be able to be replenished one at a time.

At greater than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , power to HCVS critical components/instruments will be transferred from the dedicated HCVS battery to the Division 2, UPS Y80, powered by the FLEX PDG.

Discussion of radiological and temperature constraints identified in Attachment 2A

Prior to venting, the rupture disk nitrogen manual isolation valve and the HCVS nitrogen manual isolation valve will need to be opened. Venting will be accomplished from the ASDS panel (in EFT building) or from the ROS (located in the turbine building). Radiological and temperature conditions are not expected to be significant in these areas and will be confirmed by calculation.

At >12 hours a FLEX PDG will be installed and connected to power station battery chargers used to supply power to primary containment pressure and wetwell level instrumentation. The cable connections, location of the FLEX PDG and access for refueling will be located in an area that is accessible to operators. NSPM will determine radiological conditions for the FLEX portable equipment staging areas. (OIP Open Item 3)

At >24 hours, replacement nitrogen bottles will continue to supply HCVS pneumatics, as needed. NSPM will evaluate the effects of radiological and temperature constraints on the deployment of nitrogen bottles after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . (GIP Open Item 7)

!Provide Details o~n the Vent chara'cteristicsi .,i,,*:i : .. _* . . .

Provide Details on the Vent characteristics Vent Size and Basis (EA-13-109 Section 1.2.1/INEI 13-02 Section 4.1.1)

What is the plants licensedpower? Discuss any plansfor possible increases in licensedpower (e.g. MU]R, EPU,).

What is the nominal diameter of the vent pipe in inches/Is the basis determined by venting at containment design pressure, Primary ContainmentPressure Limit (PCPL), or some other criteria (e.g. anticipatoryventing)?

Vent Capacity (EA-13-109 Section 1.2.1 /NEIJ13-02 Section 4.1.1)

Indicate any exceptions to the 1% decay heat removal criteria,including reasonsfor the exception. Provide the heat capacity of the suppressionpool in terms of time versus pressurization capacity, assuming suppressionpool is the injection source.

Vent Path andDischarge (EA 109 Section 1.1.4, 1.2.2/NEIJ3-02 Section 4.1.3, 4.1.5 andAppendix F/G)

Provides a description of Vent path, releasepath, and impact of vent path on other vent element items.

Power and Pneumatic Supply Sources (EA 1 09 Section 1.2.5 & 1.2.6/NEIJ13-02 Section 4.2.3, 2.5, 4.2.2, 4.2.6, Page 14 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Provide a discussion of electricalpower requirements, including a description of dedicated 24 hourpower supplyfrom permanently installed sources. Include a similar discussion as abovefor the valve motive force requirements. Indicate the area in the plantfrom where the installed/dedicatedpower andpneumatic supply sources are coming Indicate the areas where portable equipment will be staged after the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period, the dose fields in the area, and any shielding that would be necessary in that area.Any shielding that would be provided in those areas Location of ControlPanels (EA-13-109 Section 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.2.4, 1.2.5 /NEI 13-02 Section 4.1.3, 4.2.2, 4.2.3, 4.2.5, 4.2.6, 6.1.1 andAppendix F/G)

Indicate the location of the panels, and the dose fields in the area during severe accidents and any shielding that would be requiredin the area. This can be a qualitative assessment based on criteriain NE1 13-02.

Hydrogen (EA-13-109 Section 1.2.10, 1.2.11, 1.2.12/NEI13-02 Section 2.3,2.4, 4.1.1, 4.1.6, 4.1. 7, 5.1, & Appendix H)

State which approach or combination of approachesthe plant will take to address the control of flammable gases, clearly demarcatingthe segments of vent system to which an approach applies Unintended Cross Flow of Vented Fluids (EA-13-109 Section 1.2.3, 1.2.12 /NEI113-02 Section 4.1.2, 4.1.4, 4.1.6 and Appendix H)

Provide a description to eliminate/minimize unintended crossflow of ventedfluids with emphasis on interfacing ventilation systems (e.g. SGTS). What designfeatures are being included to limit leakage through interfacingvalves or Appendix J type testingfeatures?

Prevention of lnadvertentActuation (EA-13-109 Section 1.2. 7/NEI 13-02 Section 4.2.1)

The HCVS shall include means to prevent inadvertent actuation Component Qualifications(EA-13-109 Section 2.1/INEI113-02 Section 5.1, 5.3)

State qualification criteria based on use of a combination of safety related and augmented quality dependent on the location, function and interconnectedsystem requirements Monitoringi of HCVS (Order Elements 1.1.4, 1.2.8, 1.2.9/NEI113-02 4.1.3, 4.2.2, 4.2.4, andAppendix F/G)

Provides a description of instruments used to monitor HCVS operation and effluent. Powerfor an instrument will require the intrinsicallysafe equipment installedas part of the power sourcing Component reliable and rugg~ed performance (EA-13-109 Section 2.2/NEl113-02 Section 5.2, 5.3)

HCVS components including instrumentationshould be designed, as a minimum, to meet the seismic design requirements of the plant.

Components including instrumentationthat are not requiredto be seismically designed by the design basis"of the plant should be designedfor reliable and ruggedperformance that is capable of ensuring HCVS functionality following a seismic event. (reference ISG-JLD-2 01201 and ISG-JLD-2012-O3for seismic details.)

The components including instrumentation external to a seismic category 1 (or equivalent building or enclosure should be designed to meet the external hazards that screen-infor the plant as defined in guidance NEI112-06 as endorsed by JLD-ISG-12-Ol for OrderEA-12-049.

Use of instruments and supportingcomponents with known operatingprinciples that are supplied by manufacturerswith Page 15 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent commercial quality assurance programs, such as ISO 9001. The procurement specifications shall include the seismic requirements and/or instrument design requirements, and specify the needfor commercial design standards and testing under seismic loadings consistent with design basis values at the instrument locations.

Demonstfration of the seismic reliabilityof the instrumentationthrough methods thatpredictperformance by analysis, qualificationtesting under simulated seismic conditions, a combination of testing and analysis, or the use of experience data. Guidancefor these is based on sections 7, 8, 9, and 10 of lEEE Standard344-2004, 'IEEE Recommended Practice for Seismic Qualification of Class 1E Equipmentfor Nuclear Power GeneratingStations, " or a substantiallysimilar industrialstandardcould be used.

Demonstrationthat the instrumentation is substantially similar in design to instrumentation that has been previously tested to seismic loading levels in accordancewith the plant design basis at the location where the instrument is to be installed(g-levels andfrequency ranges). Such testing and analysis should be similar to thatperformedfor the plant licensing basis.

Vent Size and Basis The HCVS suppression pool path is designed for venting steam/energy at a nominal capacity of 1 %

decay heat removal criteria from the extended power uprate, 2004 Megawatts thermal (MWt) -

current licensed thermal power, at a containment pressure of 56 psig. This pressure is the lower of the containment design pressure and the PCPL value. The size of the wetwell portion of the HCVS (provided below in the "Vent Path and Discharge" section of this OIP) provides adequate capacity to meet or exceed the Order criteria.

Vent Capacity.

The vent is able to prevent containment pressure from increasing above the containment design pressure. The 1% capacity will be reconfirmed for the final HCVS configuration.

Vent Path and Discharge The existing HCVS vent path at MNGP connects to the wetwell vapor space through an eight inch penetration. Containment isolation is provided by two air operated valves in series, located in the torus room. The eight inch line then enters the HPCI room and connects to a rupture disk. The rupture disk will burst at 44 to 50 psig. It can be manually actuated using a dedicated rupture disk nitrogen supply by opening two solenoid operated valves that pressurize the area between the outboard containment isolation valve and the rupture disk. After the rupture disk, the pipe transitions to a 10 inch pipe that exits the Reactor Building through the HPCI roof. The vent pipe extends up the side of the reactor building to the Plenum Room roof. It then continues horizontally for approximately 60 feet before travelling vertically, adjacent to the Reactor Building vent, to an elevation 3 feet above the highest structure on the Reactor Building roof. As discussed in Part 1, the HCVS discharge is in the vicinity of the Reactor Building plenum exhaust. A layout of the MNGP buildings is provided in Figure 2.

The HCVS discharge path is routed to a point above any adjacent structure. This discharge point is above the Reactor Building such that the release point will vent away from emergency ventilation Page 16 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent system intake and exhaust openings, main control room location, location of HCVS portable equipment, access routes required following an ELAP and BDBEE, and emergency response facilities; however, these must be considered in conjunction with other design criteria (e.g., flow capacity) and pipe routing limitations, to the degree practical.

The detailed design will address missile protection as directed in HCVS-WP-04 related to limited evaluation above 30 feet. (Reference HCVS-FAQ-04; HCVS-WP-04).

Figure 2: MNGP Plant Building Layout PLANT T irineBuilin*HCVS Nitrogen Supply Wetwell Vent concrete wall Discharge F Wetwell -- Potential Portable Vent path Office, Control & FLEX Diesel Outside Administration Generator Location Reactor Reactor Building (one of two required)

Buildin gReco Building

\" Potential Portable FLEX Diesel Generator Location (one of two required)

Power and Pneumatic Supply Sources All electrical power required for operation of HCVS components will be supplied by a dedicated HCVS battery that will be designed with sufficient capacity to power HCVS instrumentation and controls for~the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . After 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , power for the HCVS loads will be transferred to the Division 2 UPS, Y80, which will be powered by an EA-12-049 FLEX PDG. The following Page 17 of75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent components will be supplied by the dedicated HCVS battery:

HCVS Temperature Monitor,

HCVS Radiation Monitor,

Two solenoids for opening the rupture disk,

One solenoid for the inboard, air operated, primary containment isolation valve,

One solenoid for the outboard, air operated, primary containment isolation valve,

Valve position indication for each of the two primary containment isolation valves.

NSPM has not completed the design of the dedicated HCVS battery. NSPM will identify the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months power supply for the MNGP HCVS. (OIP Open Item 2)

NSPM has not completed the dose evaluation for the FLEX portable equipment staging area. NSPM will determine the radiological conditions for the FLEX portable equipment staging areas in accordance with HCVS-WP-02. (OIP Open Item 3)

1. Pneumatic power for the HCVS air-operated (AOVs) is currently provided by the B train of the Alternate Nitrogen System. The plant will be modified to install a dedicated rupture disk nitrogen supply and dedicated HCVS nitrogen supply. The dedicated HCVS nitrogen supply will be designed to supply HCVS pneumatics for the two air operated containment isolation valves for the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Opening the valves requires energizing an AC powered solenoid operated valve (SOV) and providing nitrogen. The detailed design will provide a permanently installed power source and nitrogen supply adequate for the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The FLEX PDG will provide power to the HCVS after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . NSPM will identify the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months power supply for the HCVS. (OIP Open Item 2)

2. In accordance with HCVS-WP-02, as part of the design of the dedicated HCVS nitrogen supply will be designed for 8 vent cycles within the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

3. An assessment of temperature and radiological conditions will be performed to ensure that operating personnel can safely access and operate controls based on time constraints listed in Attachment 2A. NSPM will evaluate the ASDS panel and Backup HCVS Operating Station locations for accessibility, habitability, staffing sufficiency, associated pathway from the main control room, and communication capability with vent-use decision makers. (OIP Open Item 4)

4. Permanently installed HCVS equipment, including any connections required to supplement the HCVS operation during an ELAP (i.e., electric power, nitrogen), will be located in areas reasonably protected from defined hazards listed in Part 1 of this report.

5. HCVS valves required to open the flow path will be designed for remote manual operation following an ELAP, such that the primary means of valve manipulation will not rely on use of a hand wheel, reach-rod or similar means that requires close proximity to the valve (Reference FAQ HCVS-03). Any supplemental connections will be pre-engineered to minimize man-power resources and address environmental concerns. Required portable equipment will be reasonably protected from screened in hazards listed in Part 1 of this OIP.

Page 18 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent

6. Access to the locations described above will not require temporary ladders or scaffolding.

7. Following the initial 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period, additional motive force will be supplied from the replenishment of the dedicated HCVS nitrogen bottles using nitrogen bottles that are staged at a gas cylinder rack located in the Turbine Building, shielded from the HCVS by a 4 foot concrete wall. Additional bottles can be brought in as needed.

Location of Control Panels The HCVS design allows initiating and then operating and monitoring the HCVS from the ASDS panel. If the ASOS panel is not accessible during an ELAP, the Backup HCVS Operating Station, located in the Turbine Building, will be used. NSPM will evaluate the ASDS panel and the Backup HCVS Operating Station locations for accessibility, staffing sufficiency, associated pathways from the main control room, and communication capability with vent-use decision makers (OIP Open Item 4).

Hvdrogen As is required by EA-13-109, Section 1.2.11, the HCVS must be designed such that it is able to either provide assurance that oxygen cannot enter and mix with flammable gas in the HCVS (so as to form a combustible gas mixture), or it must be able to accommodate the dynamic loading resulting from a combustible gas detonation. Several configurations are available that will support the former (e.g., purge, mechanical isolation from outside air, etc.) or the latter (design of potentially affected portions of the system to withstand a detonation relative to pipe stress and support structures).

The HCVS will be designed with mechanical isolation from outside air such that the HCVS is able to provide assurance that oxygen cannot enter and mix with flammable gas in the HCVS (OIP Open Item 5).

Unintended Cross Flow of Vented Fluids The HCVS piping does not interface with any other system piping or ductwork, except for the dedicated HCVS rupture disk nitrogen supply. A check valve will be installed to prevent cross flow of vented fluids into the HCVS rupture disk nitrogen supply.

Prevention of Inadvertent Actuation EOP/SAMG operating procedures provide clear guidance that the HCVS is not to be used to defeat containment integrity during any design basis transients and accident. In addition, the HCVS will be designed to provide features to prevent inadvertent actuation due to a design error, equipment malfunction, or operator error such that any credited containment accident pressure (CAP) that would provide net positive suction head (NPSH) to the emergency core cooling system (EGGS) pumps will be available (inclusive of a design basis loss-of-coolant accident (DBLOCA)). However the EGGS pumps will not be in service during an ELAP condition because EGGS pumps will not have any power available based on the starting boundary conditions of an ELAP.

Page 19 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent EOP/SAMG operating procedures provide supplementary instructions to point out that reducing primary containment pressure will affect NPSH margin. This administrative control, along with key lock switches on the ASDS panel will prevent inadvertent vent opening.

The features that prevent inadvertent actuation are key lock switches on the ASDS panel. Valves that open the HCVS at the Backup HCVS Operating Station, which will only be used if the HCVS cannot be operated from the ASDS panel, will be secured to prevent inadvertent actuation.

Cornponent Qualifications The HCVS components downstream of the second containment isolation valve, up to the HPCI room roof are routed in seismically qualified structures. Piping outside safety related structures is designed to Class II and is supported to meet Class I seismic requirements. HCVS components that directly interface with the primary containment pressure boundary will be considered safety related, as the existing system is safety related. The primary containment system limits the leakage or release of radioactive materials to the environment to prevent offsite exposures from exceeding the guidelines of 10OCFR1 00. During normal or design basis operations, this means serving as a pressure boundary to prevent release of radioactive material. Newly installed piping and valves will be seismically qualified to handle the forces associated with the safe shutdown earthquake (SSE) back to their isolation boundaries.

Likewise, any electrical or controls component which interfaces with Class 1E power sources will be considered safety related up to and including appropriate isolation devices such as fuses or breakers, as their failure could adversely impact containment isolation and/or a safety-related power source. The remaining components will be considered Augmented Quality. Electrical and controls components will be seismically qualified and will include the ability to handle harsh environmental conditions (although they will not be considered part of the site Environmental Qualification (EQ) program).

HCVS instrumentation performance (e.g., accuracy and precision) need not exceed that of similar plant installed equipment. Additionally, radiation monitoring instrumentation accuracy and range will be sufficient to confirm flow of radionuclides through the HCVS.

The HCVS instruments, including valve position indication, process instrumentation, radiation monitoring, and support system monitoring, will be qualified by using one or more of the three methods described in the ISG, which includes:

1. Purchase of instruments and supporting components with known operating principles from manufacturers with commercial quality assurance programs (e.g., ISO 9001) where the procurement specifications include the applicable seismic requirements, design requirements, and applicable testing.

2. Demonstration of seismic reliability via methods that predict performance described in IEEE 344-2004.

3. Demonstration that instrumentation is substantially similar to the design of instrumentation Page 20 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent previously qualified.

Instrument Qualification Method*

HCVS Process Temperature ISO 9001 / IEEE 344-2004 / Demonstration HCVS Process Radiation Monitor ISO 9001 I IEEE 344-2004 / Demonstration HCVS Process Valve Position ISO 9001 / IEEE 344-2004 I Demonstration HCVS Pneumatic Supply Pressure ISO 9001 / IEEE 344-2004 I Demonstration HCVS Electrical Power Supply Availability ISO 9001 / IEEE 344-2004 I Demonstration

Note: NSPM will determine the Qualification Method for HCVS Instrumentation (OIP Open Item 6). The specific qualification method used for each required HCVS instrument will be reported in future 6 month status reports.

Monitoring of HCVS The MNGP wetwell HCVS will be capable of being manually operated during sustained operations from the ASDS panel and will meet the requirements of Order Section 1.2.4. Additionally, to meet the intent for a secondary control location of Section 1.2.5 of the Order, a readily accessible Backup HCVS Operating Station (i.e. the ROS), located in the Turbine Building, will also be incorporated into the HCVS design as described in NEI 13-02 Section 4.2.2.1.2.1. The controls and indications at the Backup HCVS Operating Station and the ASDS panel locations will be accessible and functional under a range of plant conditions, including severe accident conditions with due consideration to source term and dose impact on operator exposure, extended loss of AC power (ELAP), and inadequate containment cooling. NSPM will evaluate the ASDS panel and the Backup HCVS Operating Station locations for accessibility to the location, habitability, staffing sufficiency, and communication capability with vent-use decision makers (OIP Open Item 4).

The wetwell HCVS will include means to monitor the status of the vent system at the ASDS panel.

The wetwell HCVS will include indications for vent temperature, and effluent radiation levels adjacent to the ASDS panel. Other important information on the status of supporting systems, such as power source status and pneumatic supply pressure will be available locally by the dedicated HCVS battery (power source status) and in the Turbine Building (pneumatic supply pressure). NSPM will evaluate the HCVS battery charger location for accessibility, habitability, staffing sufficiency, associated pathways from the main control room, and communication capability with vent-use decision makers (OIP Open Item 8). Monitoring of the power source and the pneumatic pressure will be performed periodically, based on plant procedures. The wetwell HCVS includes existing DW pressure and Suppression Pool level indication at the ASDS panel location to monitor vent operation. This monitoring instrumentation provides the indication from the ASDS panel as per Requirement 1.2.4 and will be designed for sustained operation during an ELAP event. Table 2-2 summarizes the existinqj and planned instrumentation.

Page 21 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Table 2-2: Instrumentation Requirements Plant Equipment Paaee NC NIBackup Other Modification Prmtr NC NI Power Intuet ASDS HCVS Pat Rqie EA-13-109 13-02 Supply Intuet Panel Operating PLoanti Rqure Station Lcto AO-4539 HPV Yes, ISOLATION HS-4539 None None 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months nCVS Valve 128 42411 2hor INBOARD battery PoiinAO4540 HPV Yes, ISOLATION HS-4540 None None 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months HCVS OUTBOARD battery HARD PIPE Yes, Effluent VENT New Discharge 1.2.9 4.2.4.'[.2 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months RADIATION RR-4544 None None instrument Radioactivity MONITOR and RECORDER 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months HCVS battery HARD PIPE Yes, Effluent EXTERNAL New Add a new Temperature NA 4.2.2.1.8 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months SURFACE Instrument None None thermocouple TEMPERATURE and 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months HCVS battery PRIMARY CONTAINMENT - No, 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months WIDE RANGE PI-7251B None None powered from Containment 4.2.2.1.9 with PRSUEFLEX PDG Pressure and NA and FLEX PESR Wetwell Level 4.2.4.1.4 PDG SUPPRESSION No, POOL LEVEL LI-7338B None None powered from FLEX PDG BATT-ERY Lcl Yes, POWER None None Lcl part of 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Electrical MONITOR Indicator HCVS battery Power and design Pneumatic NA 4.2.4.1.3 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months HCVS Yes, Supply DEDICATED N2 Local part of Pressure SUPPLY None Pressure None dedicated PRESSURE Gauge HCVS N2

_______ ______________ _________ _________ __supply_ suplysdsig Component reliable and rugged performance The HCVS downstream of the second containment isolation valve, including piping and supports has been designed/analyzed to conform to the requirements consistent with the applicable design codes for the plant and to ensure functionality following a design basis earthquake. The HCVS electrical power supply, valve actuator pneumatic supply, and instrumentation (local and remote) components will be designed/analyzed to conform to the requirements consistent with the applicable design codes for the plant and to ensure functionality following a design basis earthquake.

Additional modifications required to meet the Order will be reliably functional at the temperature, Page 22 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent pressure, and radiation levels consistent with the vent pipe conditions for sustained operations. The instrumentation/power supplies/cables/connections (components) will be qualified for temperature, radiation level, and total integrated dose radiation for the Effluent Vent Pipe.

Conduit design will be installed to Seismic Class 1 criteria. Both existing and new barriers will be used to provide a level of protection from missiles (OIP Open Item 1) when required. (Reference HCVS-WP-04) Augmented quality requirements, will be applied to the components installed in response to this Order.

If the instruments are purchased as commercial-grade equipment, they will be qualified to operate under severe accident environment as required by NRC Order EA-1 3-1 09 and the guidance of NEI 13-02.

For the instruments required after a potential seismic event, the following methods will be used to verify that the design and installation is reliable / rugged and thus capable of ensuring HCVS functionality following a seismic event. (OIP Open Item 6) Applicable instruments are rated by the manufacturer (or otherwise tested) for seismic impact at levels commensurate with those of postulated severe accident event conditions in the area of instrument component use using one or more of the following methods:

demonstration of seismic motion will be consistent with that of existing design basis loads at the installed location;

substantial history of operational reliability in environments with significant vibration with a design envelope inclusive of the effects of seismic motion imparted to the instruments proposed at the location;

adequacy of seismic design and installation is demonstrated based on the guidance in Sections 7, 8, 9, and 10 of IEEE Standard 344-2004, IEEE Recommended Practicefor Seismic Qualification of Class 1E Equipment for Nuclear Power GeneratingStations, (Reference 27) or a substantially similar industrial standard;

demonstration that proposed devices are substantially similar in design to models that have been previously tested for seismic effects in excess of the plant design basis at the location where the instrument is to be installed (g-Ievels and frequency ranges); or

seismic qualification using seismic motion consistent with that of existing design basis loading at the installation location.

Page 23 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary Conditions for Wetwell Vent: BDBEE Venting ,

Determine venting capability for BDBEE Venting, such as may be used in an ELAP scenario to mitigate core damage.

Ref: EA-13-109 Section 1.1.4 / NEI 13-02 Section 2.2 First 24 Hour Coping Detail Provide a general description of the venting actionsforfirst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months using installed equipmnent including station modijfications that areproposed.

Ref: EA-13-109 Section 1.2.6 / NEI 13-02 Section 2.5, 4.2.2 The operation of the HCVS will be designed to minimize the reliance on operator actions for response to an ELAP and BDBEE hazards identified in part 1 of this OIP. Initial operator actions can be completed by Operators from the HCVS control station and include remote-manual initiation. The operator actions required to open a vent path are as described in Table 2-1.

Remote-manual is defined in this report as a non-automatic power operation of a component and does not require the operator to be at or in close proximity to the component. No other operator actions are required to initiate venting under the guiding procedural protocol.

The HCVS has been designed to allow initiation, control, and monitoring of venting from the ASDS panel. NSPM will evaluate the ASDS panel location for accessibility, habitability, staffing sufficiency, associated pathways from the main control room, and communication capability with vent-use decision makers (QIP Open Item 4). The ASDS panel is located in a Class I structure, and the associated path is therefore protected from hazards assumed in Part 1 of this report.

Permanently installed power and nitrogen capability will be available to support operation and monitoring of the HCVS for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Permanently installed equipment will supply nitrogen and power to HCVS for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

System control:

Active: HCVS valves are operated in accordance with EOPs, SAMGs, and/or AOPs to control DW pressure. In accordance with HCVS-WP-02, the HCVS will be designed eight (8) open/close cycles under ELAP conditions over the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months following an ELAP. Controlled venting will be permitted in the revised EPG/SAG and associated implementing EOPs and SAMGs.

ii. Passive: Inadvertent actuation protection is provided by:

o HCVS key lock switches located on the ASDS panel.

o A rupture disk is currently provided in the HCVS vent line, downstream of the Page 24 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary Conditions for Wetwell Vent: BDBEE Venting containment isolation valves. The rupture disk is designed such that it can be intentionally breached from the ASDS panel as directed by applicable procedures. The rupture disk pneumatics will be designed such that the rupture disk can be intentionally breached from the Backup HCVS Operating Station as directed by applicable procedures. The containment isolation valves must be opened to permit HCVS flow.

The rupture disk is designed to burst between 44 - 50 psig, which is less than the suppression chamber internal design pressure (56 Psig at 281 0F), the maximum suppression chamber internal pressure (62 Psig at 281 °F), or the existing HCVS design pressure (62 Psig at 309°F).

o Controls at the Backup Operating Station required to open the HCVS will be secured.

* ' ' Greater Than 24 Hour Coping Detail Provide a general description of the venting actionsfor greater than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months usingportable and installedequipment including station mnodifications that areproposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 / NEI 13-02 Section 4.2.2 After 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , available personnel will be able to connect supplemental nitrogen to the HCVS.

Connections for supplementing electrical power and nitrogen required for HCVS will be located in accessible areas with reasonable protection per NEI 12-06 that minimize personnel exposure to adverse conditions for HCVS initiation and operation. Connections will be pre-engineered quick disconnects to minimize manpower resources. A FLEX PDG will be used to ensure HCVS control power after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The response to NRC EA-12-049 demonstrates the capability for FLEX efforts to maintain the power source.

These actions provide long term support for HCVS operation for the period beyond 24 hrs to 7 days (sustained operation time period) because on-site and off-site personnel and resources will have access to the unit(s) to provide needed action and supplies.

"' ~~~~~Details: *. .. , . .* ,

Provide a brief description of Procedures / Guidelines:

Confirm that procedure/guidanceexists or will be developed to support implementation.

NEL 13-02 §6.1.2 Page 25 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary Conditions for Wetwell Vent: BDBEE Venting The operation of the HCVS is governed the Primary Containment Control Flowchart. Other site procedures for venting containment using the HCVS include:

o EOP Support Procedure C.5-3505 (Venting Primary Containment),

o EDMG A.8-05.08 (Manually Open Containment Vent Lines),

o Emergency Management Guideline 5790-110-01, o Severe Accident Management Guideline A.7-SAMG-01 (Primary Containment Flooding),

o Severe Accident Management Guideline A.7-SAMG-02 (RPV, Containment, and Radioactivity Release Control),

o Severe Accident Management Guideline A.7.-SAMG-03 (Combustible Gas Control), and o Abnormal Procedure B.04.01-05.H.2 (Alternate N2 Supply for Operating AO-4539 and AO-4540)

C.5-3505 will be revised to incorporate plant modifications made to meet EA 13-109. A new procedure will be developed to control transfer of HCVS loads from HCVS battery to Y80.

Identify modifications:

List nmodifications and describe how they support the HCVS Actions.

EA-1 2-049 Modifications o Two of three Division 2, 250 Vdc battery chargers have been modified to connect to the 480 volt FLEX PDG to repower the battery chargers. This permits powering the containment pressure and suppression pool level instruments located on the ASDS panel from the FLEX PDG. This also permits powering HCVS instrumentation and controls from the FLEX PDG after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

o Missile shielding will be provided as necessary to ensure the availability of the HCVS (L-MT-14-083).

EA-1 3-109 Modifications o A dedicated HCVS nitrogen supply will be installed as a pneumatic supply for the containment isolation valves.

o A dedicated HCVS rupture disk nitrogen supply will be installed.

o Manual valves will be installed on the dedicated HCVS nitrogen supply and the dedicated HCVS rupture disk nitrogen supply to allow manual actuation of the HCVS from the Backup HCVS Operating Station, located in the Turbine Building.

Page 26 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent PartP2 Boundary Conditions for ,Wetwell Vent:* B EE Vnting*:

o A dedicated HCVS power supply will be installed o The existing HCVS radiation monitor will be replaced with a radiation monitor that meets the requirements of EA-1 3-1 09. (See Table 2-2) o A new HCVS temperature element will be installed. (See Table 2-2) o A mechanical isolation device will be installed on the existing 1HCVS pipe such that the HCVS is able to provide assurance that oxygen from outside air cannot enter the HCVS and mix with flammable gas in the HCVS (OIP Open Item 5).

o The existing "T" at the top of the existing Hardened Vent System pipe will be replaced with a straight section of pipe and a weather cap.

Key Venting Parameters:

List instrumentationcreditedfor this venting actions. Clearly indicate which of those already exist in the plant and what others will be newly installed (to comply with the vent order)

Initiation, operation and monitoring of the HCVS venting will rely on the following key parameters and indicators (refer also to Table 2-2):

Key Parameter Component Identifier Indication Location HCVS Effluent temperature TBD ASOS panel HCVS Pneumatic supply pressure TBD Local at dedicated HCVS nitrogen supply.

HCVS valve position indication HS-4539 and HS-4540 ASDS panel Initiation, operation and monitoring of the HCVS system will rely on several existing ASDS panel key parameters and indicators which are qualified or evaluated to Regulatory Guide (RG) 1.97 per the existing plant design:

Key Parameter Drywell pressure Suppression Pool level

{PI-7251 Component Identifier LI-7338B B

Indication Location ASDS panel ASDS panel Reactor pressure PI-4012 ASOS panel Page 27 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part,2 Boundary Conditions for Wetwell Vent: Severe Accident Venting ...

Determine venting capability for Severe Accident Venting, such as may be used in an ELALP scenario to mitigate core damage.

Ref: EA-13-109 Section 1.2.10 INEI 13-02 Section 2.3

'**... ... :First 24 Hour Co ing Detail '

Provide a general description of the venting actionsforfirst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months using installed equipment including station miodifications that are proposed.

Ref: EA-13-109 Section 1.2.6 / NEI 13-02 Section 2.5, 4.2.2 The operation of the HCVS will be designed to minimize the reliance on operator actions for response to an ELAP and severe accident events. Severe accident event assumes that specific core cooling actions from the FLEX strategies identified in the response to Order EAl2-049 were not successfully initiated. Access to the reactor building will be restricted as determined by the RPV water level and core damage conditions. Initial actions will be completed by Operators at the ASDS panel or in the Turbine Building at the Backup HCVS Operating Station and will include remote-manual actions at the dedicated HCVS nitrogen supply and the dedicated rupture disk nitrogen supply. The operator actions required to open a vent path were previously listed in the BDBEE Venting Part 2 section of this report (Table 2-I).

Permanently installed power and nitrogen capable will be available to support operation and monitoring of the HCVS for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Specifics are the same as for BDBEE Venting Part 2.

System control:

i. Active: Same as for BDBEE Venting Part 2 ii. Passive: Same as for BDBEE Venting Part 2.

~Details:

Provide a generaldescription of the venting actionsfor greaterthan 241 hours0.00279 days 0.0669 hours 3.984788e-4 weeks 9.17005e-5 months usingportable and installed equipmlent including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 I NEI 13-02 Section 4.2.2 Page 28 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent

,, ,,...... Part 2 Boundary Conditions, for Wetwell Vent: BDBEE Venting ,

Specifics are the same as for BDBEE Venting Part 2.

These actions provide long term support for HCVS operation for the period beyond 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to 7 days (sustained operation time period) because on-site and off-site personnel and resources will have access to provide needed action and supplies.

, ,, ..... .. ... .First 24 Hour Coping Detail .. . ..

Provide a brief description of Procedures / Guidelines:

Confirm thatprocedure/guidanceexists or will be developed to support implementation.

The operation of the HCVS is governed the same for SA conditions as for BDBEE conditions.

Existing guidance in the SAMGs directs the plant staff to consider changing radiological conditions in a severe accident.

Identify modifications."

List modifications and describe how they support the HCVS Actions.

The same as for BDBEE Venting Part 2.

Key Venting Parameters:

List instrumentation creditedfor the HCVS Actions. Clearly indicate which of those already exist in the plant and what others will be newly installed (to comply with the vent order)

Initiation, operation and monitoring of the HCVS venting will rely on the following key parameters and indicators:

Key Parameter Component Identifier Indication Location HCVS effluent temperature TBD ASDS panel HCVS pneumatic supply pressure TBD Local at HCVS nitrogen supply Page 29 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary: Conditions for Wetwell Vent:, BDBEE Venting HCVS valve position indication HS-4539 and HS-4540 ASDS panel HCVS power status TBD Local at HCVS battery HCVS effluent radiation monitor RM-4544 ASDS panel Initiation, operation and monitoring of the HCVS system will rely on several existing ASDS panel key parameters and indicators that are the same as for BDBEE Venting Part 2.

HCVS indications for HCVS pneumatic supply pressure and HCVS power status will be installed locally to comply with EA-1 3-109. HCVS effluent temperature and HCVS effluent radiation will be installed at the ASDS panel to comply with EA-1 3-109.

Page 30 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary Conditions for Wetwell Vent: HCVS Support Equipment Functions Determine venting capability support functions needed Ref: EA-13-109 Section 1.2.8, 1.2.9 / NEI 13-02 Section 2.5, 4.2.4, 6.1.2

....* " *, : BDBEE Venting, . . ..... .

Provide a general description of the BDBEE Venting actions supportfunctions. Identif methods and strategy(ies) utilized to achieve venting results.

Ref: EA-13-109 Section 1.2.9 / NEI 13-02 Section 2.5, 4.2.2, 4.2.4, 6.1.2 Containment integrity is initially maintained by permanently installed equipment. All containment venting functions will be performed from the ASDS panel or the Backup HCVS Operating Station, located in the Turbine Building.

Venting will require support from DC power as well as the dedicated HCVS nitrogen supply and the dedicated rupture disk nitrogen supply. A dedicated HCVS power supply will provide sufficient electrical power for HCVS operation for greater than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Before the dedicated HCVS battery is depleted, a portable FLEX PDG, as detailed in the response to Order EA-12-049, will be credited to supply electrical power to the HCVS after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

...... .. Severe Accident Venting '....

Provide a general description of the Severe Accident Venting actions supportfunctions. Identify methods and strategy(ies) utilized to achieve venting results.

Ref: EA-13-109 Section 1.2.8, 1.2.9 I NEI 13-02 Section 2.5, 4.2.2, 4.2.4, 6.1.2 The same support functions that are used in the BDBEE scenario would be used for severe accident venting

~Details Provide a brief description of Procedures / Guidelines:

Confirm thatprocedure/guidanceexists or will be developed to support implementation.

Most of the equipment used in the HCVS is permanently installed. The key portable items are the portable FLEX PDG and nitrogen bottles needed to supplement the pneumatic supply to the HCVS Page 31 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary Conditions for Wetwell Vent: HCVS Support Equipment Functions valves after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Use of portable equipment will be per existing procedure.

Identify modifications."

List mocifications and describe how they support the HCVS Actions.

FLEX modifications applicable to HCVS operation are identified in BDBEE Venting, Part 2.

Key Support Equipment Parameters:

List instrumentation creditedfor the support equipment utilized in the venting operation.

Clearly indicate which of those already exist in the plant and what others will be newly installed (to comply with the vent order)

Local control features of the FLEX PDG electrical load and fuel supply.

Pressure gauge on dedicated HCVS nitrogen supply bottles.

Page 32 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary conditions for Wetwell Vent: HCVS Venting Portable Equipment Deployment Provide a general description of the venting actions using portable equipment including nmodifcations that are proposed to maintain and/or support safety functions.

Ref: EA-13-109 Section 3.1 / NEI 13-02 Section 6.1.2, D.1.3.1 Deployment pathways for compliance with Order EA-12-049 are acceptable without further evaluation needed except in areas around the Reactor Building or in the vicinity of the HCVS piping.

Deployment in the areas around the Reactor Building or in the vicinity of the HCVS piping will allow access, operation and replenishment of consumables with the consideration that there is potential Reactor Core Damage and HCVS operation.

' ~Details:

Provide a brief description of Procedures!/ Guidelines:

Confirm thatprocedure/guidanceexists or will be developed to support implementation.

Operation of the portable equipment is the same as for compliance with Order EA-12-049 thus they are acceptable without further evaluation.

HCVS Actions Modifications Protection of connections Per compliance with Order N/A Per compliance with Order EAI2-049 EA-1 2-049 (FLEX) j______________(FLEX)

Page 33 of 75

HardenedMonticello Nuclear Generating Plant Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3: Boundary Conditions for EA-1 3-1 09, Option B.2 G eneral:... .... .. .....

Licensees that use Option B. ] of EA-] 3-] 09 (SA Capable DW Vent without SA WA) must develop their own QIP. This template does not provide guidancefor that option.

Licensees using Option B.2 of EA 1 09 (SA WA and SA WM or 545°FSAD W Vent (SAD V) with SA WA) may use this template for their QIP submittal. Both SA WM and SAD V require the use of SA WA and may not be done independently.

The HCVS actions under Part 2 apply to all of the following."

This Part is divided into the following sections."

3.1." Severe Accident Water Addition (SA WA) 3.1.A." Severe Accident Water Management (SA WM) 3.1.B." Severe Accident DW Vent (545 deg F)

Provide a sequence of events and identify any time constraint required for success including th~e basis for the time constraint. ...

SA WA and SA WM or SAD VActions supportingSA conditions that have a time constraint to be successful should be identified with a technical basis and ajustificationprovided that the time can reasonably be met (for example, a walkthrough of deployment). Actions already identified under the HCVS part of this template need not be repeatedhere.

The time to establish the water addition capability into the RPV or DW should be less than 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months from the onset of the loss of all injection sources.

Electrical generators satisfying the requirements of EA-12-049 may be credited for powering components and instrumentation needed to establish a flow path.

Time Sensitive Actions (TSAs) for the purpose of SAWA are those actions needed to transport, connect and start portable equipment needed to provide SA WA flow or provide power to SA WA components in the flow path between the connection point and the RPV or drywell. Actions needed to establish power to .SAWA instrumentationshould also be included as TSAs.

Ref: NEI 13-02 Section 6.1.1.7.4.1, 1.1.4, 1.1.5 The operation of the HCVS using SAWA and SAWM/SADV will be designed to minimize the reliance on operator actions in response to hazards listed in Part 1. Initial operator actions will be completed by plant personnel and will include the capability for remote-manual initiation from the ASDS panel or the Backup HCVS Operating Station, located in the Turbine Building.

Timelines (see attachments 2.1 .A for SAWA/SAWM) were developed to identify required operator response times and actions. The timelines are an expansion of Attachment 2A and begin either as core damage occurs (SAWA) or after initial SAWA injection is established and as flowrate is adjusted for option B.2 (SAWM). The timelines do not assume the core is ex-vessel and the actions taken are appropriate for both in-vessel and ex-vessel core damage conditions.

Page 34 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1: Boundary Conditions for SAWA Table 3.1 - SAWA Manual Actions . . . .

Primary Action Primary Location / Notes

________________________Component_______________

1. Establish HCVS capability in

ASDS Panel / Backup

Applicable to SAWA/SAWM accordance with Part 2 of this HCVS Operating Station strategy guidance.

2. Establish SAWA/SAWM flow

FLEX PDG Staging Area

Stage FLEX PDG path

Turbine Building

Layout cables and connect

Main Control Room FLEX PDG to electrical distribution

Repower the Low Pressure Coolant Injection (LPCI) swing bus (OIP Open Item 9)

Open LPCI isolation valve from control room using hand switch

3. Connect FLEX Portable Diesel = Discharge Canal

Alternate Location at Intake Pump (PDP) to water source

4. Connect FLEX PDP discharge

5 inch portable fire

Route hoses from discharge to injection piping hoses canal to RHR/RHRSW cross-tie located in Turbine Building.

5. Inject to RPV using FLEX PDP

From RHR/RHRSW *Valves (RHRSW-68 and (diesel) cross-tie located in RHRSW-14) are operated Turbine Building. manually.

Initial SAWA injection rate is 305 gpm

6. Monitor SAWA indications

Pump flow *Flow meter procedurally o Turbine Building / Flow controlled to be installed meter installed on 5 inch during layout of 5 inch hose fire hose from the portable diesel

HCVS Valve Position pump to the RHR/RHRSW

HS-4539 and HS-4540 / cross-tie.

_________________________Located on ASDS panel Page 35 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1: Boundary Conditions for SAWA

7. Use SAWM to maintain

ASDS panel and

Monitor OW pressure and availability of the Wetwell vent RHR/RHRSW cross-tie, Suppression Pool level at (Part 3.1 .A) located in Turbine ASOS panel.

Building

Control SAWM at

Drywell Pressure RHR/RHRSW cross-tie.

Suppression Pool Level Excess pump flow is returned to the discharge canal as needed by throttling manual valve RHRSW-12.

SAWM flowrate is 61 gpm.

8. Power primary containment

FLEX PDG staging area . Layout cables and connect pressure and wetwell level

Turbine Building FLEX PDG and Division 2, instruments from EA-12-049

EFT Building 250 Vdc battery chargers.

FLEX PDG

Repower Division 2, 250 Vdc battery chargers.

D*iscUssionobftirmeline SAWA identified items . .,::.. ..... ;*J HCVS operations are discussed under Phase 1 of EA-1 3-109 (Part 2 of this OIP).

8 Hours - Establish electrical power and other EA-12-049 actions needed to support the strategies for EA-13-109, Phase 1 and Phase 2. Action being taken within the reactor building under EA 049 conditions after RPV level lowers to 2/3 core height must be evaluated for radiological conditions assuming permanent containment shielding remains intact. (HCVS-FAQ-12) Other actions required are assumed to be in-line with the FLEX timeline submitted in accordance with the EA-12-049 requirements.

Less than 8 Hours - Initiate SAWA flow to the RPV. Having the HCVS in service will assist in minimizing the peak DW pressure during the initial cooling conditions provided by SAWA.

Severe Accident Operation Determine operatingrequirementsfor SA WA, such as may be used in an ELAP scenario to mitigate core damage.

Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NEI 13-02 Section 1.1.6, 1.1.4.4 Page 36 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1: Boundary Conditions for SAWA It is anticipated that SAWA will be used in Severe Accident Events based on presumed failure of injection systems or presumed failure to implement an injection system in a timely manner leading to core damage. This does not preclude the use of the SAWA system to supplement or replace the EA-12-049 injection systems if desired. SAWA will consist of both portable and installed equipment.

The motive force equipment needed to support the SAWA strategy shall be available prior to t=8 hours from the loss of injection (assumed at T=0).

The SAWA flow path includes methods to minimize exposure of personnel to radioactive liquids /

gases and potentially flammable conditions by inclusion of backflow prevention. AO-10-46A is an installed check valve in the RHR system, downstream of the RHR injection isolation valves.

AO-1 0-46A will prevent leakage when the FLEX POP is secured (See Attachment 3, Sketch 3a).

Description of SAWA actions for first 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months s:

T<1 hr:

No evaluation required for actions inside the reactor building for SAWA. Expected actions are:

o None T=I - 8 hr:

Evaluation of core gap and early in vessel release impact to reactor building access for SAWA actions is required. It is assumed that reactor building access is limited due to the source term at this time unless otherwise noted. (Refer to HCVS-FAQ-12 for actions in T=1-7 hr) Expected actions are:

o None

Establish flow to the RPV using SAWA systems. Begin injection at a maximum rate, not to exceed 305 gpm.

o Steps 2, 3, 4, and 5 of Table 3.1 above

Establish electrical power for indications using EA-12-049 FLEX PDG o Steps 2 and 8 of Table 3.1 above T<8 -12 hr:

Continue injection for 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months after SAWA injection begins at initial SAWA rate.

o Steps 6 of Table 3.1 above T<12 hrs:

Proceed to SAWM actions (Part 3.1.A) o Step 7 of Table 3.1 above Page 37 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1: Boundary Conditions for SAWA

,* * *. ... , .Gr.eater Than, 24 Hour Coping Detail*, *...

Provide a general description of the SA WA actionsfor greaterthan 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months usingportable and installed equipment including station modifcations that are proposed.

Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3/ NEI 13-02 Section 4.2.2.4.1.3.1, 1.1.4, SAWA Operation is the same for the full period of sustained operation. If SAWM is employed flow rates will be directed to preserve the availability of the HCVS wetwell vent (see 3.1 .A).

- " " * *~D eta ils: .. .*. . . . . ,

Details of Design Characteristics/Performance Specifications SA WA shall be capable of providing an RPV injection rate of30O0 gpm within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months of a loss of all RP V injection following an ELAP/Severe Accident. SA WA shall meet the design characteristicsof the HCVS with the exception of the dedicated24 hour power source. Hydrogen mitigation is provided by backfflow preventionfor SA WA.

Ref: EA-13-109 Attachment 2, Section B.2.1, B.2.2, B.2.3/ NEI 13-02 Section 1.1.4 Equipment Locations/ControlslInstrumentation The locations of the SAWA equipment and controls, as well as ingress and egress paths will be evaluated for the expected severe accident conditions (temperature, humidity, radiation) for the Sustained Operating period. Equipment has been evaluated to remain operational throughout the Sustained Operating period. Personnel exposure and temperature / humidity conditions for operation of SAWA equipment will not exceed the limits for Emergency Response Organization (ERO) dose and plant safety guidelines for temperature and humidity (OIP Open Item 3).

The FLEX Portable Diesel Pump (PDP) will be staged at the discharge canal. Two 5 inch fire hoses will be run between the portable diesel pump and the Turbine Building. Near the Turbine Building entrance, the two 5 inch fire hoses will be combined into a single 5 inch hose that is run to the RHR/RHRSW cross-tie. A flow meter will be included in the flow path after the fire hoses are combined, but before the hose is connected to the injection isolation valve at the RHR/RHRSW cross-tie (RHRSW-68). Once connected, RHRSW-68 is opened to admit water into the RHR/RHRSW cross-tie, at which point the Emergency RHR Injection Isolation Valve (RHRSW-14) can be opened to inject water into the RHR system. With the LPCI injection isolation valve open (MO-2014), the RHR system will inject into the RPV. RPV injection flow is controlled by throttling RHRSW-14 as needed to maintain the desired flow. Excess pump flow is routed back to the discharge canal through installed piping by opening the isolation valve between RHR and RHRSW (RHRSW-12). See Attachment 3, Sketch 3.

Page 38 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1: Boundar Conditions for SAWA Evaluations for projected SA conditions (radiation / temperature) will indicate that personnel can complete the initial and support activities without exceeding the ERO-allowable dose for equipment operation or site safety standards. (reference HCVS-WP-02, Plant-Specific Dose Analysis for the Venting of Containment during the SA Conditions) (PIP Open Item 3).

Electrical equipment and instrumentation will be powered from the existing station batteries and from AC distribution systems that are powered form the EA-12-049 portable DG. The battery chargers are also powered from the FLEX PDG to maintain the battery capacities during the Sustained Operating period. The indications include:

Parameter Instrument Location Power Source / Notes DW Pressure PI-7251B ASDS panel Station batteries plus EA-1 2-049 generator Suppression Pool LI-7338B ASDS panel Station batteries plus Level EA-1 2-049 generator SAWA Flow Flow meter staged on Installed during hose No power source hose staging required The instrumentation and equipment being used for SAWA and supporting equipment will be evaluated to perform for the Sustained Operating period under the expected radiological and temperature conditions (OIP Open Item 3).

Equipment Protection Any SAWA component and connections external to protected buildings have been protected against the screened-in hazards of EA-12-049 for the station. Portable equipment used for SAWA implementation meets the protection requirements for storage in accordance with the criteria in NEI 12-06, Revision 0.

Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NEI 13-02 Section 5.1.1, 5.4.6, 1.1.6 Provide a brief description of Procedures / Guidelines:

Confirm that procedure/guidanceexists or will be developed to support implementation.

Ref: EA-13-109 Attachment 2, Section A.3.1, B.2.3 I NET 13-02 Section 1.3, 6.1.2 Guidance has been or will be developed to:

. Stage FLEX PDP at the discharge canal*

Page 39 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1: Boundary Conditions for SAWA

Layout and connect hoses from the FLEX PDP to the RHR/RHRSW cross-tie*

Start and run the FLEX PDP*

Stage the FLEX PDG*

Repower station battery chargers from FLEX PDG*

Repower the LPCI swing bus from FLEX PDG

Verify OPEN at least one LPCI injection flow path

Establish and control RPV injection using RHRSW-68, RHRSW-14, and RHRSW-12 as needed*

Transfer HCVS power from dedicated HCVS power to Division 2 UPS, Y80

Existing FLEX Support Guideline Identify modifications:

List miodifications and describe how they support the SA WA Actions.

Ref: EA-13-109 Attachment 2, Section B.2.2, / NEI 13-02 Section 4.2.4.4, 7.2.1.8, Appendix I Two modifications are required to support SAWA Actions:

1. To establish SAWA flowrate within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months and repower the station battery chargers from the FLEX PDG within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , a modification to the east side of the site security perimeter is required. This will provide a second access portal into the plant that can be used independent of off-site personnel.

2. To establish SAWA flowrate within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , one of the LPCI injection isolation valves must be opened. A modification to the power distribution system is required. This will allow the LPCI swing bus to be powered from the FLEX PDG independent of off-site personnel, allowing the LPCI injection isolation valve to be opened from the main control room.

Component Qualifications:

State the qualificationusedfor equipmnent supportingSA WA Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NEI 13-02 Section 1.1.6 Permanently installed plant equipment shall meet the same qualifications as described in Part 2 of this OIP. Temporary/Portable equipment shall be qualified and stored to the same requirements as FLEX equipment as specified in NEI 12-06 Rev 0. SAWA components are not required to meet NEI Page 40 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1: Boundary Conditions for SAWA 13-02, Table 2-1 design conditions.

Page 41 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1 .A: Boundary Conditions for SAWAISAWM Time periods for the maintaining SAWM actions such that the WetweII vent SA WMActions supporting SA conditions that have a time constraintto be successful should be identified with a technical basis and ajustificationprovided that the time can reasonably be met (for example, a walkthrough of deployment). Actions already identified under the HCVS part of this template need not be repeatedhere.

There are three time periodsfor the maintainingSA WM actions such that the WW vent remains available to remove decay heatfrom the containment:

SA WM can be maintainedfor >7 days without the needfor a drywell vent to maintainpressure below PCPL or containment design pressure, whichever is lower.

o Under this approach, no detail concerningplant nmodifications or procedures is necessary with respect to how alternate containment heat removal will be provided.

SA WMcan be maintainedfor at least 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , but less than 7 days before DWpressure reaches PCPL or design pressure, whichever is lower.

o Under this approach, afunctional description is required of how alternate containment heat removal might be establishedbefore D Wpressure reaches PCPL or design pressure whichever is lower. Under this approach,physical plant modifications and detailedprocedures are not necessary, but written descriptions of possible approachesfor achieving alternate containment heat removal andpressure control will be provided.

SA WM can be maintainedfor <72 hours SAWM strategy can be implemented but for less than 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months before DW pressure reaches PCPL or design pressure whichever is lower.

o Under this approach, afunctional description is requiredof how alternatecontainment heat removal might be establishedbefore D Wpressure reaches PCPL or design pressure whichever is lower. Under this approach,physical plant modifications and detailedprocedures are requiredto be implemented to insure achieving alternate containmentheat removal andpressure control will be providedfor the sustained operatingperiod.

Ref: NEI 13-02 Appendix C.7 SAWM can be maintained for > 7 days without the need for a DW vent to maintain pressure below PCPL or containment design pressure, whichever is lower.

Basis for SAWM~ time frame Option 1 - SAWM can be maintained .qreater than or equal to 7 days:

MNGP is bounded by the evaluations performed in BWROG TP-201 5-008 and representative of the reference plant in NEI 13-02 figures C-2 through C-6. (C.7.1.4.1) and will be confirmed.

Instrumentation relied upon for SAWM operations is DW Pressure, Suppression Pool level and SAWA flow. DW Pressure and Suppression Pool Level are initially powered by station batteries, and then by the EA-12-049 FLEX PDG, which is placed in-service prior to core breach. The SAWA Page 42 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1 .A: Boundary Conditions for SAWAISAWM flow meter is installed during hose layout, and does not require AC power to operate. The DG will provide power throughout the Sustained Operation period (7 days). DW Temperature monitoring is not a requirement for compliance with Phase 2 of the order, but some knowledge of temperature characteristics provides information for the operation staff to evaluate plant conditions under a severe accident and provide confirmation to adjust SAWA flow rates. (0.7.1.4.2, C.8.3.1)

Suppression Pool level indication is maintained throughout the Sustained Operation period, so the HCVS remains in-service.

Table 3.1l.B -*SAWM Manual Actions . *, o :.. ...

Primary Action Primary Location / Notes Component

1. Lower SAWA injection Turbine Building e Control to maintain containment and rate to control Wetwell parameters to ensure Wetwell Suppression Pool Level vent remains functional.

and decay heat

61 gpm minimum capability is removal maintained for greater than 7 days.

2. Control to SAWM Turbine Building

SAWM flow rates will be monitored flowrate for using the following instrumentation containment control / o FLEX PDP (EA-12-049) Flow decay heat removal a Suppression Pool Level a DW pressure

SAWM flow rates will be controlled using RHRSW-14 and RHRSW-12 as needed

3. Establish alternate * >7 days.

source of decay heat removal

4. Secure SAWA / SAWM Turbine Building and

When reliable alternate containment Discharge Canal decay heat removal is established.

SAWM Time Sensitive Act~ions Time Sensitive SAWM Actions:

12 Hours - Initiate actions to maintain the Wetwell vent capability by lowering injection rate, while maintaining the cooling of the core debris (SAWM). Monitor SAWM critical parameters while ensuring the Wetwell vent remains available.

24 Hours - Transfer HCVS loads (instrumentation and controls) from dedicated HCVS battery to Page 43 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1 A: Boundary Conditions for SAWAISAWM FLEX PDG.

SAWM Severe Accident Operation Determine operatingrequirementsfor SA WM, such as may be used in an ELAP scenario to mitigate core damage.

Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NET 13-02 Appendix C It is anticipated that SAWM will only be used in Severe Accident Events based on presumed failure of plant injection systems per direction by the plant SAMGs. Refer to attachment 2.1 .D for SAWM SAMG language additions.

First 24 Hour Coping Detail Provide a general description of the SA WM actionsfor first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months using installedequipment including station modifications that are proposed.

Given the initial conditionsfor EA-13-109."

]3DBEE occurs with ELAP

Failure of all injection systems, including steam-powered injection systems Ref: EA-13-109 Section 1.2.6, Attachment 2, Section B.2.2, B.2.3 I NEI 13-02 2.5, 4.2.2, Appendix C, Section C.7 SAWA will be established as described as stated above. SAWM will use the installed instrumentation to monitor and adjust the flow from SAWA to control the pump discharge to deliver flowrates applicable to the SAWM strategy.

Once the SAWA initial low rate has been established for 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , the flow will be reduced while monitoring DW pressure and Suppression Pool level. SAWM flowrate can be lowered to maintain containment parameters and preserve the Wetwell vent path. SAWM will be capable of injection for the period of Sustained Operation.

Greater Than 24 Hour Coping Detail Provide a general description of the SA WM actionsfor greaterthan 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months using portable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8, Attachment 2, Section B.2.2, B.2.3 / Nfl 13-02 Section 4.2.2, Appendix C, Section C.7 Page 44 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1!.A: Boundary Conditions for SAWA/SAWM SAWM can be maintained >7 days:

The SAWM flow strategy will be the same as the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months until "alternate reliable containment heat removal and pressure control" is reestablished. SAWM flow strategy uses the SAWA flow path.

A MNGP specific SAWA/SAWM analysis will be required.

No additional modifications are being proposed for SAWM.

, ...... * ,, D etails:

Details of Design Characteristics/Performance Specifications Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NEI 13-02 Section Appendix C3 SAWM shall be capable of monitoring the containment parameters (DW pressure and Suppression Pool Level) to provide guidance on when injection rates shall be reduced, until alternate containment decay heat/pressure control is established. SAWA will be capable of injection for the period of Sustained Operation.

Equipment Locations/Controls/Instrumentation Describe locationfor SA WM monitoring and control.

Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NEL 13-02 Appendix C, Section C.8, Appendix I The SAWM control location is the same as the SAWA control location. Local indication of SAWM flow rate is provided by a portable flowmeter installed on the hose from the FLEX PDP. The flow meter will be near the SAWA injection point.

Injection flowrate is controlled by manually throttling RHRSW-14 and RHRSW-12, located in the Turbine Building.

Suppression Pool level and OW pressure are read at the ASDS panel using indicators powered by the FLEX PDG installed under EA-12-049. These indications are used to control SAWM flowrate to the RPV.

Key Parameters:

List instrumentation creditedfor the SA WM Actions.

Page 45 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Part 3.1.A: Boundary Conditions for SAWAISAWM Parameters used for SAWM are:

DW Pressure

Suppression Pool Level

SAWM Flowrate The DW pressure and Suppression Pool level instruments are qualified to RG 1.97 and are the same as listed in part 2 of this OIP. The SAWM flow instrumentation will be qualified for the expected environmental conditions expected when needed (OIP Open Item 6).

Page 46 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 3.1 .B: Boundary Conditions for SAWA/SADV

i*i* ;ilApplicability of Wetwel Design Considration Not applicable for MNGP.

Table 3.1 .C SADv MaUal Actios

- ;i .. .... ,i, Severe Accident Venting.. ., , ,.. .*.. * . "* '" ;...° "

First 24 Hou Coping Deai Greater Than 24 HOur coping Detai*!*

Page 47 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 4: Progqrammnatic Controls. Training, Drills and Maintenance Identify how the prograrrmmtic controls Will be met.

Provide a description of the programmatic controls equipmentprotection, storage and deployment and equipnent quality addressingthe impact of temperature and environment Ref: EA-13-109 Section 1.2.10, 3.1, 3.2 / NEI 13-02 Sections 5, 6.1.2, 6.1.3, 6.2 Program Controls:

The HCVS venting actions will include:

Site procedures and programs are being developed in accordance with NEI 13-02 to address use and storage of portable equipment relative to the Severe Accident defined in NRC Order EA-1 3-1 09 and the hazards applicable to the site per Part 1 of this OIP.

Routes for transporting portable equipment from storage location(s) to deployment areas will be developed as the response details are identified and finalized. The identified paths and deployment areas will be analyzed for radiation and temperature to ensure they are accessible during Severe Accidents.

Procedures:

Procedures will be established for system operations when normal and backup power is available, and during ELAP conditions.

The HCVS procedures will be developed and implemented following the plants process for initiating or revising procedures and contain the following details:

appropriate conditions and criteria for use of the HCVS,

when and how to place the HCVS in operation,

the location of system components,

instrumentation available,

normal and backup power supplies, o directions for sustained operation, including the storage location of portable equipment,

training on operating the portable equipment, and

testing of portable equipment.

EOPISAMGs provide supplementary instructions to point out that reducing primary containment pressure will affect Net Positive Suction head margin.

NSPM will establish provisions for out-of-service requirements of the HCVS and compensatory measures. The following provisions will be documented in a controlled document:

The provisions for out-of-service requirements for HCVSISAWA functionality are applicable in Page 48 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 4: Programnmatic Controls. Training., Drills and Maintenance Modes 1, 2 and 3.

If for up to 90 consecutive days, the primary or alternate means of HCVS/SAWA operation are non-functional, no compensatory actions are necessary.

If for up to 30 days, the primary and alternate means of HCVS/SAWA operation are nonfunctional, no compensatory actions are necessary.

If the out of service times exceed 30 or 90 days as described above, the following actions will be performed through the sites corrective action program:

o Document the cause(s) of the non-functionality, o The actions to be taken and the schedule for restoring the system to functional status and prevent recurrence, o Initiate action to implement appropriate compensatory actions, and o Restore full HCVS functionality at the earliest opportunity not to exceed one full operating cycle.

Describe training plan .... ..

List trainingplansfor affected organizationsor describe the planfor trainingdevelopment Ref: EA-13-109 Section 3.2 / NEL 13-02 Section 6.1.3 Personnel expected to perform direct execution of the HCVS/SAWA/SAWM actions will receive necessary training in the use of plant procedures for system operations when normal and backup power is available and during ELAP conditions. The training will be refreshed on a periodic basis and as any changes occur to the HCVS/SAWA/SAWM actions, systems or strategies. Training content and frequency will be established using the Systematic Approach to Training (SAT) process.

Identify~how the drills and exercise paramet:ers will be met. ...

Alignment with NE1 13-06 and 14-01 as codified in NTTF Recommendation 8 and 9 rulemaking The Licensee should demonstrate use of the HCVS/SA WA/SA WM system in drills, tabletops, or exercises as follows:

Hardenedcontainment vent operation on normal power sources (no ELAP).

During FLEX demonstrations (as required by EA-12-049): Hardenedcontainment vent operationon backup power andfrom primary or alternate location during conditions of ELAP/loss of UHS with no core damage.

System use isfor containment heat removalAND containmentpressure control.

HCVS operation on backup power andfrom primary or alternate location during conditions of ELAP/loss of UHS with core damage. System use is for containment heat removal AND containmentpressure control with potentialfor combustible gases (Demonstrationmay be in conjunction with SAG change).

Page 49 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Part 4: Progqrammatic Controls! Training, Drills and Maintenance

Operationfor sustainedperiod with SAWA and SA WMto provide decay heat removal and containmentpressure control.

Ref: EA-13-109 Section 3.1 / NEI 13-02 Section 6.1.3 The site will utilize the guidance provided in NEI 13-06 and 14-01 for guidance related to drills, tabletops, or exercises for HCVS operation. In addition, the site will integrate these requirements with compliance to any rulemaking resulting from the NTTF Recommendations 8 and 9.

Descr'ibe maintenance plan:

Describe the elements of the maintenanceplan

The maintenanceprogram should ensure that the HCVS/SA WA/SA WMequipment reliability is being achieved in a manner similar to that requiredfor FLEX equipment. Standardindustry templates (e.g., EPRI) and associatedbases niay be developed to define specific maintenance and testing.

o Periodictesting andfrequency should be determined based on equipment type, expected use and manufacturer'srecommendations (/further details areprovided in Part 6 of this document,).

o Testing should be done to verify design requirements and/or basis. The basis should be documented and deviationsfr'om vendor recommendations and applicable standardsshould bejustified.

,o Preventive maintenance should be determined based on equipment type and expected use. The basis should be documented and deviationsfrom vendor recommendations and applicablestandardsshould bejustified.

o Existing work controlprocesses may be used to control maintenance and testing.

HCVS/SA WA permanent installed equipment should be maintained in a manner that is consistent with assuringthat it performs itsfunction when required.

o HCT'S/SA WA permanently installed equipment should be subject to maintenance and testing guidance provided to verify properfun ction.

HCVS/SA WA non-installed equipment should be stored and maintained in a manner that is consistent with assuring that it does not degrade over long periods of storage and that it is accessiblefor periodic maintenance and testing.

Ref: EA-13-109 Section 1.2.13 1 NEI 13-02 Section 5.4, 6.2 NSPM will utilize the standard EPRI industry Preventive Maintenance (PM) process as guidance (similar to the Preventive Maintenance Basis Database) for establishing the maintenance calibration and testing actions for HCVS/SAWA/SAWM components. The control program will include maintenance guidance, testing procedures and frequencies established based on type of equipment and considerations made within the EPRI guidelines, or in accordance with site program.

NSPM will implement the following operation, testing and inspection requirements for the HCVS and SAWA to ensure reliable operation of the system.

Page 50 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 4: Programmatic Controls, Training. Drills and Maintenance Table 4-1: Testing and Inspection Requirements Description Frequency Cycle the HCVS and installed SAWA valves 1 and the Once per every 2 operating cycle interfacing system boundary valves not used to maintain containment integrity during Mode 1, 2 and 3. For HCVS valves, this test may be performed concurrently with the control logic test described below.

Cycle the HCVS and installed SAWA check valves not Once per every other4 operating cycle used to maintain containment integrity during unit operations 3 Perform visual inspections and a walk down of HCVS and Once per every other 4 operating cycle installed SAWA components Functionally test the HCVS radiation monitors. Once per operating cycle Leak test the.HCVS. 1. Prior to first declaring the system functional;

2. Once every three operating cycles thereafter; and

3. After restoration of any breach of system boundary within the buildings Validate the HCVS operating procedures by conducting an Once per every other operating cycle open/close test of the HCVS control function from its control location and ensuring that all HCVS vent path and interfacing system boundary valves 5 move to their proper (intended) positions.

1Not required for HCVS and SAWA check valves.

2 After two consecutive successful performances, the test frequency may be reduced to a maximum of once per every other operating cycle.

3 Not required if integrity of check function (open and closed) is demonstrated by other plant testing requirements.

4 After two consecutive successful performances, the test frequency may be reduced by one operating cycle to a maximum of once per every fourth operating cycle.

5 Interfacing system boundary valves that are normally closed and fail closed under ELAP conditions (loss of power and/or air) do not require control function testing under this part. Performing existing plant design basis function testing or system operation that reposition the valve(s) to the HCVS required position will meet this requirement without the need for additional testing.

Page 51 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 5: Milestone Schedule Provide a milestone schedule This schedule should include:

Modifications timeline

Procedure guidance development complete o HCVS Actions o Maintenance

Storage plan (reasonable protection)

Staffing analysis completion

Long term use equipment acquisition timeline

Training completion for the HCVS Actions The dates specifically requiredby the orderare obligated or committed dates. Other dates are planned dates subject to change. Updates will be provided in the periodic (six month) status reports.

Ref: EA-13-109 Section D.1, D.3 / NEI 13-02 Section 7.2.1 The following milestone schedules are provided. The dates are planning dates subject to change as design and implementation details are developed. Any changes to the following target dates will be reflected in the subsequent 6 month status reports.

Phase 1 Milestone Schedule:

Phase 1 Milestone Schedule Milestone Target Activity Comments Completion Status Date Hold preliminary/conceptual design meeting June 2014 Complete Submit Overall Integrated Implementation Plan June 2014 Complete Submit 6 Month Status Report Dec. 2014 Complete Submit 6 Month Status Report June 2015 Complete Submit 6 Month Status Report Dec. 2015 Complete Simultaneous with with this Phase 20OIP.

submittal June 2016 Started 2016 based on current project schedule.

Page 52 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 5: Milestone Schedule Submit 6 Month Status Report June 2016 Not Started Operations Procedure Changes Developed Dec. 2016 Not Revised from Started September 2016 based on current project schedule.

Site Specific Maintenance Procedure Developed Dec. 2016 Not Revised from Started September 2016 based on current project schedule.

Submit 6 Month Status Report Dec. 2016 Not Started Training Complete May 2017 Not Started Implementation Outage May 2017 Not Started Procedure Changes Active May 2017 Not Started Walk Through Demonstration/Functional Test May 2017 Not Started Submit Completion Report July 2017 Not Started Phase 2 Milestone Schedule:

Phase 2 Milestone Schedule Milestone Target Activity Comments Completion Status Date Hold preliminary/conceptual design meeting Oct 2015 Complete Submit Overall Integrated Implementation Plan Dec 2015 Complete with this submittal Submit 6 Month Status Report June 2016 Not Started Page 53 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Part 5: Milestone Schedule Submit 6 Month Status Report Dec 2016 Not Started Submit 6 Month Status Report June 2017 Not Started Submit 6 Month Status Report Dec. 2017 Not Started Design Engineering On-site/Complete June 2018 Not Started Submit 6 Month Status Report June 2018 Not Started Submit 6 Month Status Report Dec. 2018 Not Started Operations Procedure Changes Developed Dec. 2018 Not Started Site Specific Maintenance Procedure Developed Dec. 2018 Not Started Training Complete May 2019 Not Started Implementation Outage May 2019 Not Started Procedure Changes Active May 2019 Not Started Walk Through Demonstration/Functional Test May 2019 Not Started Submit Completion Report July 2019 Not Started Page 54 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 1: HCVSISAWA Portable Equipment BDBEE Severe Performance Criteria Maintenance / PM List portable equipment Venting Accident requirements Venting Nitrogen Cylinders X X Required number of bottles Check periodically for pressure, will be determined during replace or replenish as needed design of dedicated HCVS nitrogen supply.

(ISE Open Item 2)

FLEX PDG (and associated X X EA-12-049 Per Response to EA-12-049 equipment)______________

FLEX PDP (and associated X X 305 gpm first 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Per Response to EA-13-109 equipment) 61 gpm thereafter ________________

Page 55 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 2A: Sequence of Events Timeline - HCVS SAWA Injection Flow Control $AWM flow rate begins 4305 gpm) using diywell pressure and suppression pool level 550 RCK start ELAP delred CASE 1 FLEX Successful Ret: FLEX OIP No Injection No Injection Lev¢el at TAF S t "23 hrs CASE2

,*,6

RCIC Late Failure

~Ret: SECY-12-0157 V V Ceubbameutvm*irtg apt sq.mptudh~

Ul V

t =24 Its CS

~1=~

RCIC Early Failure Ref: SOARCA tneiahanenlVtnliag bau~NL~$~,upplyd TiamdaIlIYSpmsww 0U~FO jbused..peewewliq NCWb.tkuyswtum. RmrqlenI~kmeIat sup$~andiqi~abb

~PcP4 ~p.ed1ah.bwat=24hmvs Legend Adequate Care Cooling Maintaind EIF~fl

.......... Injecton Lost Referenlces:

-- Increased Shine and L~eakag~e of Radionuclides Primarily from Wetei Case 1: FLEX Overall Inegaed Plan (Reference 28)

""" HCVS Post Core Damage Dose ['valuation Requhe Case 2: SECY-12-0157 - ML 12344AD30

" HCVS Time Evaluation Required Cae3: SOARCA - ML13ISOAOS3 Page 56 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 2.1 .A: Sequence of Events Timeline - SAWA / SAWM Sustained Operation Period SAWA Injection Flow begins (305 gpm)

Control SAWM flow rate U-using drywell pressure and suppression pool level 0 - - - - a

- Stage FLEX Portable Diesel Pump

- Stage FLEX Portable Diesel Generator

- OPEN LPCi Injection Valve Page 57 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 2.1.B: Sequence of Events Timeline - SADV Not applicable to MNGP.

Page 58 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 2.1 .C: SAWA / SAWM Plant-Specific Datum AT 305 GPM SAWA FLOW, RATE OF RISE IS0.29 FT/HR*

AT 61 GPM SAWM FLOW, RATE OF RISE IS 0.058 FT/HR*

DOES NOT CONSIDER MASS LOSS RATE OF STEAM LEAVING CONTAINMENT THROUGH WETWELL VENT

,SPILLOVER HEIGHT DRYWELL FLOOR ELEVATION Page 59 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 2.1.D: SAWM SAMG Approved Language The following general cautions, prioritiesand methods will be evaluated for plant specific applicabilityand incorporatedas appropriateinto the plant specific SAMGs using administrativeprocedures for ERG/SAG change control process and implementation. SAMGs are symptom based guidelines and therefore address a wide variety of possible plant conditions and capabilities while these changes are intended to accommodate those specific conditions assumed in Order EA-13-109. The changes will be made in a way that maintains the use of SAMGs in a symptom based mode while at the same time addressing those conditions that may exist under extended loss of AC power (ELAP) conditions with significant core damage including ex-vessel core debris.

Actual Approved Lanquage that will be incorporated into site SAMG*

Cautions:

Addressing the possible plant response associated with adding water to hot core debris and the resulting pressurization of the primary containment by rapid steam generation.

Addressing the plant impact that raising suppression pool water level above the elevation of the suppression chamber vent opening elevation will flood the suppression chamber vent path.

Priorities:

With significant core damage and RPV breach, SAMGs prioritize the preservation of primary containment integrity while limiting radioactivity releases as follows:

Core debris in the primary containment is stabilized by water addition (SAWA)

Primary containment pressure is controlled below the Primary Containment Pressure Limit (Wetwell venting)

Water addition is managed to preserve the Mark 1/Il suppression chamber vent paths, thereby retaining the benefits of suppression pool scrubbing and minimizing the likelihood of radioactivity and hydrogen release into the secondary containment (SAWM)

Methods:

Identify systems and capabilities to add water to the RPV or DW, with the following generic guidance:

Use controlled injection if possible.

Inject into the RPV if possible.

Maintain injection from external sources of water as low as possible to preserve suppression chamber vent capability.

Actual language may vary by acceptable site procedure standards, but intent and structure should follow this guidance.

Page 60 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 3: Conceptual Sketches (Conceptual sketches, as necessary to indicate equipment which is installed or equipment hookups necessary for the HCVS Actions)

Sketch 1: Electrical Layout of System (preliminary)

Instrumentation Process Flow

Electrical Connections Sketch 2: P&ID Layout of Wetwell Vent (preliminary)

Piping routing for vent path - Wetwell Vent

Demarcate the valves (in the vent piping) between the currently existing and new ones

Wetwell Vent Instrumentation Process Flow Diagram

Egress and Ingress Pathways to ROS, Battery Transfer Switch, DG Connections and Deployment location

Site layout sketch to show location/routing of Wetwell vent piping and associated components. This should include relative locations both horizontally and vertically Sketch 3: P&ID Layout of SAWA (preliminary)

Piping routing for SAWA path

SAWA instrumentation process paths

SAWA connections

Include a piping and instrumentation diagram of the vent system. Demarcate the valves (in the vent piping) between the currently existing and new ones.

Ingress and egress paths to and from control locations and manual action locations

Site layout sketch to show locations of piping and associated components. This should include relative locations both horizontally and vertically Page 61 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan I- NEW -- - -I I

DIV II ESSENTIAL MCC-144 AC INPUT POWER I I

I I

I

CONNECTION FOR PORTABLE DIESEL I GENERATOR I I

STATIC MANUAL SWITCH BYPASS I SWITCH HCVS I

~IJiI BA1TERY HCVS I

ASDS INSTRUMENTATION INVERTER I

RPV LEVEL I I

RPV PRESSURE I

CONTAINMENT PRESSURE I

TORUS LEVEL I I

TORUS TEMPERATURE I I I

ri'..V* *UL.II'IUIU V,'iLVP.. I I

HCVS VALVE POSITION INDI CATION

HCVS TEMPERATURE MONI7rOR I

HCVS RADIATION MONITOR

-JI FM4RCJ.4cvs P*e Sup- PhseI cP.d.e I.. - -- -- - ...

Sketch la: Electrical Layout of System (preliminary)

Page 62 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Division I Division II Essential Load Center Essential Load Center K,,

~2 ) -I MCC-131 MCC-132 MCC-133A MCC-134 MCC-141 MCC-142 (E) {E) MCC-143A MCC-144

~~~1 I MCC-133B (E) LPCI Swing Bus MCC-143B (E)

F ) I

,.J 0 9*

4~. NI 0

r,'J 0 LU I-fl LU 4-. I-.

LU LU NI 02

-j Y

Recirc Pump RHR X-tie ILPCI Injection RHR X-tie Recirc Pump LPCI Injection Isolation Isolation Isolation Isolation Isolation Isolation Valves Valve Valves Valves Valve Valves L

Sketch l b: Electrical Layout of System Page 63 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan HCVS - VENT LAYOUT - PHASE II alP I RED BLACK- EXUSTING

- ADDED TO MEET EA-1 3-1 09 PHASE I

)AI-651 [EXISTING AN 2 TIE IN NH-36049-10 (B,6)1 110 F:4RC*CVS-VENT LAYOUT-PHASE OPd',.g RUPTURE DISK Sketch 2: Layout of Current HCVS with Planned Phase 1 Modifications Page 64 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan RIVER

"HOSE BLACK - PERMANENTLY INSTALLED PLANT EQUIPMENT RED - PORTABLE EQUIPMENT STAGED IN FLEX BUILDINGS I

F:'NRC'.AWA Laot{rnr)*

+ VALVES LOCATED IN REACTOR BUILDING Sketch 3a: P&ID Layout of SAWA (preliminary)

Page 65 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan RIVER REPOWER HCVS LOADS F:*NRC*OIP PRESENTATION SITE LAYOUT.dwg Sketch 3b: P&ID Layout of SAWA (preliminary)

Page 66 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 4: Failure Evaluation Table Failure with Alternate Functional Failure Action Impact on Mode Failure Cause Alternate Action Containment Venting?

Failure of Vent to Valves fail to open/close No action needed, a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months battery will be No Open on Demand due to loss of normal power provided Failure of Vent to Valves fail to open/close No action needed, a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months battery will be No Open on Demand due to loss of alternate provided power (long term)

Failure of Vent to Valves fail to open/close Manual valves located at the Backup HCVS No Open on Demand due to complete loss of Operating Station will be used to open the batteries (long term) HCVS Failure of Vent to Valves fail to open/close Replace nitrogen bottles No Open on Demand due to loss of normal pneumatic air supply Failure of Vent to Valves fail to open/close Manual valves located at the Backup HCVS No Open on Demand due to SOV failure Operating Station will be used to open the HCVS SAWA /SAWM TBD TBD TBD Specific Table 4A: Wetwell HCVS Failure Evaluation Table Page 67 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Attachment 5: References

1. NRC Generic Letter 89-16, "Installation of a Hardened Wetwell Vent," dated September 1, 1989 (ADAMS Accession No. ML060760371).

2. NRC Order EA-12-049, "Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,"

dated March 12, 2012 (ADAMS Accession No. ML12054A735).

3. NRC Order Number EA-12-050, "Issuance of Order to Modify Licenses with Regard to Requirements for Reliable Hardened Containment Vents," dated March 12, 2012 (ADAMs Accession No. ML12054A682).

4. NRC Order Number EA-12-051, "Issuance of Order to Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," dated March 12, 2012 (ADAMS Accession No. ML12054A679).

5. NRC Order Number EA-1 3-1 09, "Issuance of Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," dated June 6, 2013 (ADAMs Accession Number ML13143A334).

6. NRC Interim Staff Guidance JLD-ISG-2012-01 ,"Compliance with Order EA 049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," Revision 0, dated August 29, 2012 (ADAMS Accession No. ML12229A174).

7. NRC Interim Staff Guidance JLD-ISG-2012-02, "Compliance with Order EA 12-050, Order Modifying Licenses with Regard to Requirements for Reliable Hardened Containment Vents," Revision 0, dated August 29, 2012 (ADAMS Accession Number ML12229A475).

8. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with Order EA-13-09, 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).

9. NRC Responses to Public Comments, "Japan Lessons-Learned Project Directorate Interim Staff Guidance JLD-ISG-2012-02: Compliance with Order EA-12-050, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents," dated August 29, 2012 (ADAMS Accession No. ML12229A477).

10. NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,"

Revision 0, dated August 2012 (ADAMS Accession No. ML12242A378).

11. NEI 13-02, "Industry Guidance for Compliance with Order EA-1 3-109' Revision 0, dated November 2013 (ADAMS Accession Number ML13316A853).

12. NEI 13-06, "Enhancements to Emergency Response Capabilities for Beyond Design Basis Accidents and Events," Draft Revision 0, dated March 2014 (ADAMS Accession No. ML14049A002).

Page 68 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan

13. NEI 14-01, "Emergency Response Procedures and Guidelines for Extreme Events and Severe Accidents," Draft Revision 0, dated March 2014 (ADAMS Accession No. ML14049A005).

14. NE! FAQ HCVS-01, "HCVS Primary and Alternate Controls and Monitoring Locations,"

Revision 2, dated April14, 2014 (ADAMS Accession No. ML14120A289).

15. NEI FAQ HCVS-02, "HCVS Dedicated Equipment," Revision 0, dated March 11,2014 (ADAMS Accession No. ML14120A289).

16. NEI FAQ HCVS-03, "HCVS Alternate Control Operating Mechanisms," Revision 1, dated April 2, 2014 (ADAMS Accession No. ML14120A289).

17. NEI FAQ HCVS-04, "HCVS Release Point," Revision 1, April 14, 2014 (ADAMS Accession No. ML14120A289).

18. NEI FAQ HCVS-05, "HCVS Control and 'Boundary Valves,"'" Revision 2, April 14, 2014 (ADAMS Accession No. ML14120A289).

19. NEI FAQ HCVS-06, "HCVS FLEX and Generic Assumptions' Revision 2, April 14, 2014 (ADAMS Accession No. ML14120A289).

20. NE! FAQ HCVS-07, "HCVS Source Term from SFP," Revision 0, March 11, 2014 (ADAMS Accession No. ML14120A289).

21. NEI FAQ HCVS-08, "HCVS Instrument Qualification," Revision 1, April14, 2014 (ADAMS Accession No. ML14120A289).

22. NEI FAQ HCVS-09, "HCVS Toolbox Approach for Collateral Actions," Revision 1, dated April14, 2014 (ADAMS Accession No. ML14120A289).

23. NEI White Paper HCVS-WP-01, "HCVS Dedicated and Permanently Installed Motive Force," dated April15, 2014 (ADAMS Accession No. ML14120A298 and ML14120A295).

24. NEI White Paper HCVS-WP-02, "Hardened Containment Vent System (HCVS) Cyclic Operations Approach," Draft Revision A, dated April 2, 2014.

25. NEI White Paper HCVS-WP-03, "Hydrogen/Carbon Monoxide Control Measures,"

Draft Revision, dated April4, 2014.

26. NEI White Paper HCVS-WP-04, "Missile Evaluation for HCVS Components 30 Feet Above Grade," Revision 0, dated August 17, 2015.

27. IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class I E Equipment for Nuclear Power Generating Stations, dated June 8, 2005.

28. NSPM Letter to NRC, "Monticello Nuclear Generating Plant's Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)," L-MT-13-017, dated February 28, 2013 (ADAMS Accession No. ML13066A066).

29. NSPM Letter to NRC, "MNGP's Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Hardened Containment Vents (Order Number EA-12-050)," L-MT-13-015, dated February 28, 2013 (ADAMS Accession No. ML13060A411).

Page 69 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan

30. NSPM Letter to NRC, "Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)," L-MT-13-016, dated February 28, 2013 (ADAMS Accession No. ML13060A447).

31. 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, dated April 2015. (ADAMS Accession No. MLI5I04AI118)

32. Consideration of Additional Requirements for Containment Venting Systems for Boiling Water Reactors with Mark I and Mark II Containments, SECY-12-0157, (ADAMS Accession No. ML12344A030)

33. NUREG/CR-71 10, VI, RI, State-of-the-Art Reactor Consequence Analyses (SOARCA) Project: Peach Bottom Integrated Analysis, (ADAMS Accession No. MLL31 50A053).

34. NEI HCVS-FAQ-1 0, Severe Accident Multiple Unit Response

35. NEI HCVS-FAQ-I1I, Plant Response During a Severe Accident

36. NEI HCVS-FAQ-12, Radiological Evaluations on Plant Actions Prior to HCVS Initial Use

37. NEt HCVS-FAQ-1 3, Severe Accident Venting Actions Validation Page 70 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase I and 2 Overall Integrated Plan Attachment 6: Changes/Updates to this Overall Integrated Implementation Plan This Overall Integrated Plan has been updated in format and content to encompass both Phase 1 and Phase 2 of Order EA-1 3-109. Any significant changes to this plan will be communicated to the NRC staff in the 6 Month Status Reports.

Phase Change Description An additional alternative to JLD-ISG-2013-02 and NEI 13-02 has been Phase Iadded. The HCVS design temperature will be 3090°F, not 350°F.

A dedicated HCVS rupture disk nitrogen supply will be installed to burst the rupture disk if needed. Previously communicated that the rupture Phase Idisk nitrogen was to be supplied from Train B, Alternate Nitrogen System.

A dedicated HCVS nitrogen supply will be installed to provide Phase 1 pneumatics to HCVS air operated suppression pool PCIVs. Previously communicated that the HCVS pneumatics were to be supplied from Train B, Alternate Nitrogen System.

Manual valves will be installed on both the dedicated HCVS rupture disk nitrogen supply and the dedicated HCVS nitrogen supply to bypass the solenoid valves to allow the HCVS to be actuated manually from the Phase I Backup HCVS Operating Station. Previously communicated that the solenoid valves were to be moved from the reactor building to the Backup HCVS Operating Station.

Phase ~A dedicated HCVS battery will be installed to power HCVS instrumentation and controls for the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the event.

The HCVS will be designed with mechanical isolation from outside air Phase I such that the HCVS is able to provide assurance that oxygen cannot enter and mix with flammable gas in the HCVS.

A check valve will be installed on the dedicated HCVS rupture disk Phase 1 nitrogen supply line to prevent cross flow of vented fluids. Previously Phase I communicated the HCVS piping does not interface with any other system piping, or ductwork except the Alternate Nitrogen System.

Valves that open the HCVS at the Backup HCVS Operating Station will Phase I be secured to prevent inadvertent actuation. Previously communicated the valves would be locked.

Page 71 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Change Description A battery power monitor will be installed on the dedicated HCVS battery to monitor electrical power. Previously communicated power monitoring would be done using the battery charger voltmeter or a hand held FLUKE meter.

Have identified missile shielding of HCVS as being required to meet EA-1 2-049 rather than EA-1 3-109 requirements.

The existing Hardened Vent System radiation monitor will be replaced with a radiation monitor that meets the requirements of EA-1 3-109.

Page 72 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Attachment 7: List of Overall Integqrated Plan Open Items Table 7.1 - alP Open items Open Action Comment 1 Follow industry guidance on missile protection for HCVS. Phase 1 2 Identify the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months power supply for the HCVS. Phase 1 3 Determine radiological conditions for the FLEX portable Phase 1 equipment staging areas.

Evaluate the ASDS panel and Backup HCVS Operation 4 Station locations for accessibility, habitability, staffingPhs1 sufficiency, associated pathways from the control room and PhsI communication capability with vent-use decision makers.

5 Determine approach or combination of approaches to Phase 1 control hydrogen.

Determine the Qualification Method for HCVS 6 Instrumentation. Pae Evaluate the effects of radiological and temperature 7 constraints on the deployment of nitrogen bottles after 24 Phase 1 hours1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months .

Evaluate HCVS battery charger location for accessibility, 8 habitability, staffing sufficiency, associated pathways from Phase 1 the control room and communication capability with vent-use decision makers.

9 Determine approach to repower LPCI swing bus from FLEX Phase 2 PDG Page 73 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan Table 7.2 - ISE Open Items ISE ISE Section Open Action Reference Item 1 Make available for NRC staff audit the final sizing evaluation Section 3.2.1 for HCVS batteries/battery charger including incorporation Section 3.2.2.4 into FLEX PDG loading calculation. Section 3.2.3.1 Section 3.2.3.2 Section 3.2.4.1 Section 3.2.4.2 Section 3.2.5.1 Section 3.2.5.2 Section 3.2.6 2 Make available for NRC staff audit documentation of the Section 3.2.1 HCVS nitrogen pneumatic system design including sizing and Section 3.2.2.4 location. Section 3.2.3.1 Section 3.2.3.2 Section 3.2.4.1 Section 3.2.4.2 Section 3.2.5.1 Section 3.2.5.2 Section 3.2.6 3 Make available for NRC staff audit an evaluation of Section 3.2.1 temperature and radiological conditions to ensure that Section 3.2.2.3 operating personnel can safely access and operate controls Section 3.2.2.4 and support equipment. Section 3.2.2.5 Section 3.2.2.10 Section 3.2.4.1 Section 3.2.4.2 Section 3.2.5.2 Section 3.2.6 4 Make available for NRC staff audit analyses demonstrating Section 3.2.2.1 that HCVS has the capacity to vent the steam/energy Section 3.2.2.2 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.

Page 74 of 75

Monticello Nuclear Generating Plant Hardened Containment Venting System (HCVS) Order Phase 1 and 2 Overall Integrated Plan ISE ISE Section Open Action Reference Item 5 Make available for NRC staff audit the seismic and tornado Section 3.2.2.3 missile final design criteria for the HCVS stack.

6 Make available for NRC staff audit the descriptions of local Section 3.2.2.5 conditions (temperature, radiation and humidity) anticipated Section 3.2.2.9 during ELAP and severe accident for the components (valves, Section 3.2.2.10 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 Section 3.2.2.5 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 Section 3.2.2.6 address hydrogen detonation and deflagration.

9 Provide a description of the strategies for hydrogen control Section 3.2.2.6 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 Section 3.2.2.9 instrumentation and controls (existing and planned) necessar to implement this order including qualification methods.

11 Make available for NRC staff audit documentation of an Section 3.2.2.9 evaluation verifying the existing containment isolation valves, relied upon for the HCVS, will open under the maximum expected differential pressure during BDBEE and severe accident wetwell venting.

Page 75 of 75