ML15358A042

Third Six-Month Status Report, Phase 2 Overall Integrated Plan, and Responses to Phase 1 Interim Staff Evaluation Open Items in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents.

ML15358A042
Person / Time
Site:	Pilgrim
Issue date:	12/17/2015
From:	Dent J Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-13-109
Download: ML15358A042 (65)

Text

___

i Nuclear Power Station Pilgrigym Entergy Nuclear Operations, Inc.

600 Rocky Hill Road Plymouth, MA 02360

• ) John A. Dent, Jr.

Site Vice President December 17, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852

SUBJECT:

Pilgrim Nuclear Power Station's Third Six-Month Status Report, Phase 2 Overall Integrated Plan, and Responses to Phase 1 Interim Staff Evaluation Open Items 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)

Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35

REFERENCES:

1. NRC Order Number EA-1 3-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions,"~

dated June 6, 2013 (Accession No. ML13143A334).

2. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with Order EA-13-1 09, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated November 2013 (Accession No. ML13304B836).

3. NRC Endorsement of Industry "Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-1 3-1 09), Rev 0" (Accession No. ML14128A219).

4. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA-1 3-1 09, To Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated November 2013.

5. Entergy's Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-1 3-1 09),

dated June 30, 2014.

LETTER NUMBER 2.15.082

Dear Sir or Madam:

On June 6, 2013, the U. S. Nuclear Regulatory Commission (NRC) issued an order (Reference

1) to Entergy Nuclear Operations, Inc. (Entergy). Reference 1 was immediately effective and directs Entergy to install a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris. Specific requirements are outlined in Attachment 2 of Reference 1.

PNPS Letter 2.15.082 Page 2 of 3 Reference I required submission of a Phase 1 overall integrated plan pursuant to Section IV, Condition D. Reference 3 endorses industry guidance document NE! 13-02, Revision 0 (Reference 4) with clarifications and exceptions identified in Reference 2. Reference 5 provided the Entergy overall integrated plan.

Reference 1 requires submission of a status report at six-month intervals following submittal of the overall integrated plan. References 2 and 4 provide direction regarding the content of the status reports. The purpose of this letter is to provide the third six-month status report pursuant to Section IV, Condition D, of Reference 1, that delineates progress made in implementing the requirements of Reference 1. The attached status report (Attachment 1) provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any.

Reference I also requires submission of an overall integrated plan (QIP) by December 31, 2015, for Phase 2 of the order. Therefore, along with the Phase 1 six-month status report, the OIP for Phase 2 of the Order pursuant to Section IV, Condition D.2, of Reference 1 is enclosed as Attachment 2.

Additionally, PNPS's responses to the Phase 1 Interim Staff Evaluation Open Items are contained in Attachment 3.

Entergy plans to permanently cease operation of PNPS no later than June 1, 2019. The Hardened Containment Vent System Phase 1 and Phase 2 strategies documented in this submittal are accurate descriptions of the current planned modifications and/or strategies to satisfy the requirements of NRC Order EA-1 3-1 09.

This letter contains no new regulatory commitments.

Should you have any questions concerning the content of this letter, please contact Mr. Everett (Chip) Perkins, Jr. at (508) 830-8323.

I declare under penalty of perjury that the foregoing is true and correct; executed on December 17, 2015.

Sincerely, JAD/rm b

PNPS Letter 2.15.082 Page 3 of 3 Attachments: 1] Pilgrim Nuclear Power Station's Third 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) 2] Pilgrim Nuclear Power Station's Phase 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-1 3-1 09) 3] Pilgrim Nuclear Power Station's Responses to Phase 1 Interim Staff Evaluation Open Items cc: Mr. Daniel H. Dorman Regional Administrator, Region I U.S. Nuclear Regulatory Commission 2100 Renaissance Boulevard, Suite 100 King of Prussia, PA 19406-1415 U. S. Nuclear Regulatory Commission Director, Office of Nuclear Reactor Regulation Washington, DC 20555-0001 Ms. Booma Venkataraman, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8C2A Washington, DC 20555 Mr. John Giarrusso Jr.

Planning, Nuclear and Preparedness Section Chief Mass. Emergency Management Agency 400 Worcester Road Framingham, MA 01702 NRC Resident Inspector Pilgrim Nuclear Power Station

ATTACHMENT 1 To PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Third 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)

(3 pages)

Attachment 1 PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Third Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109) 1 Introduction Pilgrim Nuclear Power Station (PNPS) developed an Overall Integrated Plan (OIP) (Reference 1 in Section 8), documenting the installation of a Hardened Containment Vent System (HCVS) that provides a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris, in response to Reference 2. This attachment provides an update of milestone accomplishments since submittal of the Phase 10CIP and the First and Second Six Month Status Report, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments The following milestone(s) have been completed since the development of the OIP (Reference 1),

and are current as of December 18, 2015.

• The Overall Integrated Plan was issued on June 30, 2014.

• The First Six Month Status Report was issued on December 16, 2014

• The Second Six Month Status Report was issued on June 30, 2015

• The Interim Staff Evaluation (ISE) was received on March 24, 2015 3 Milestone Schedule Status The following provides an update to Part 5 of the OIP. It provides the activity status of each item, and whether the expected completion date has changed. The dates are planning dates subject to change as design and implementation details are developed.

Milestone Target Activity Comments Completion Date Status Complete HCVS Gap Analysis June 2014 Complete Submit Overall Integrated Plan .June 2014 Complete Submit 6 Month Status Report December 2014 Complete Submit 6 Month Status Report June 2015 Complete December 2015 Complete Simultaneous Phase 20QIP with Submit 6 Month Status Report Design Engineering On-site/Complete July 2016 Started

Milestone Target Activity Comments Completion Date Status Submit 6 Month Status Report June 2016 Not Started Operations Procedure Changes Developed December 2016 Not Started Site Specific Maintenance Procedure Developed December 2016 Not Started Submit 6 Month Status Report December 2016 Not Started Training Complete December 2016 Not Started Implementation Outage March 2017 Not Started Procedure Changes Active March 2017 Not Started Walk Through Demonstration/Functional Test March 2017 Not Started Submit Completion Report June 2017 Not Started 4 Changes to Compliance Method There are no changes to the compliance method as documented in the Phase 10OIP (Reference 1).

5 Need for RelieflRelaxation and Basis for the RelieflRelaxation As noted in this submittal cover letter, Entergy plans to permanently cease operation of PNPS no later than June 1, 2019. The Hardened Containment Vent System Phase 1 and Phase 2 strategies documented in this submittal are accurate descriptions of the current planned modifications and/or.

strategies to satisfy the requirements of NRC Order EA-1 3-109.

6 Open Items from Overall Integrated Plan and Interim Staff Evaluation PNPS has received the Interim Staff Evaluation (ISE) with Open Items identified (Reference 7).

These open items have been addressed in an attachment to this status report submittal.

7 Interim Staff Evaluation Impacts There are no potential impacts to the Interim Staff Evaluation identified at this time.

8 References The following references support the updates to the Phase 0I aP described in this enclosure.

1. Pilgrim's 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), dated June 30, 2014.

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

3. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA-1 3-1 09, To Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated November 2013.

4. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with 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 November 2013 (Accession No. ML13304B836).

5. NRC Endorsement of Industry "Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-1 3-1 09) Rev 0" (Accession No. ML14128A219).

6. Nuclear Regulatory Commission AUdits of Licensee Responses to Phase 1 of Order EA 109 to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions (Accession No. ML14126A545).

7. Nuclear Regulatory Commission Interim Staff Evaluation dated March 24, 2015, "Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-1 3-1 09 (Severe Accident Capable Hardened Vents). (Accession No. ML15043A754) (PNPS Letter 1.15.016).

ATTACHMENT 2 To PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Phase 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-1 3-1 09)

• (50 pages)

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Table of Contents:

General Integrated Plan Elements and Assumptions Part 1:

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 3.1A Boundary Conditions for SAWA/SAWM Part 3.IB 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 .1.0: 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 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Introduction In 1989, the NRC issued Generic Letter 89-16, "Installation of a Hardened Wetwell Vent," to all licensees of 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 Torus 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.

On March 19, 2013, the Nuclear Regulatory Commission (NRC) Commissioners directed the staff per Staff Requirements Memorandum (SRM) for SECY 0 157 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-13-109, Issuance of Order to Modifying Licenses withi Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accidents, June 6, 2013. The Order (EA-13-109) 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 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 drywell 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 drywell 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-l13-109 through Interim Staff Guidance (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 Revision 0 and 1, Compliance with OrderEA-13-109, Severe Accident Reliable Hardened Containment Vents, with clarifications. Except in those cases in which a licensee proposes an acceptable alternative method for complying with Order EA-13-109, the NRC staff will use the methods described in the ISGs to evaluate licensee compliance as presented in submittals required in Order EA-13-109.

The Order also requires submittal of an overall integrated plan which will provide a description of how the requirements of the Order will be achieved. This document provides the Overall Integrated Plan (OIP) for complying with Order EA-13-109 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 EA 13-109.

Page 2 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 The submittals required are:

• OIP for Phase 1 of EA-13-109 was required to be submitted by Licensees to the NRC by June 30, 2014. The NRC requires periodic (6 month) updates for the 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-13-109 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 20GIP submittal by means of a combined Phase 1 and 20OP.

[] Thereafter, the 6 month updates will be for both the Phase 1 and Phase 2 actions until complete, consistent with the requirements of Order EA- 13-1 09.

Note: At the Licensee's option, the December 2015 six month update for Phase 1 is included with this Phase 20OIP submittal.

The Plant venting actions for the EA-13-109, Phase 1 severe accident capable venting scenario can be summarized by the following:

• The HCVS will be initiated via manual action from the either the Main Control Room (MCR) 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.

o 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 at least 7 days.

The Phase 2 actions can be summarized as follows:

• The PNIPS FLEX Severe Accident Strategy is based on the use of Severe Accident Water Addition (SAWA), Severe Accident Water Management (SAWM), and Severe Accident Wetwell Venting (SAWV) to achieve safe shutdown conditions in the best manner possible for the given Beyond-Design-Basis External Event (BDBEE). The "HCVS Phase 2" Strategy is a seamless transition of the FLEX SAWA / SAWM / SAWV Strategy, i.e., Phase 2 is simply an extension of the FLEX-Phase 1 Severe Accident Strategy that is implemented as early as possible to mitigate core damage as shown in the Attachment 2 Figures of the EA-1 3-109 Phase 1 Overall Integrated Plan (OIP) with the SAWMV injection rates controlled to utilize the available Torus water capacity as effectively as possible to continue with only Wetwell (Torus) venting f*or the event duration.

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

• Utilization of Severe Accident Water Management (SAWMV) to control injection and Torus level to ensure the HCVS (Phase 1) Wetwell vent (SAWV) will remain functional for the removal of decay heat from Containment.

Page 3 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 o Ensure that the decay heat can be removed from the Containment for at least 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 drywell 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.

oParameters measured include Containment pressure, Torus level, SAWA flowrate and the HCVS parameters listed above.

Page 4 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 1: General Integrated Plan Elements and Assumptions Extent to which the guidance, JLD-ISG-2013-02, JLD-ISG-2015-01 and NEI 13-02 (Revision 1),. ,:

are being followed. Identify any deviations.

Include a description of any alternativesto the guidance. A technicaljusti~fication and basisfor the alternative needs to be provided. This will likely require a pre-meeting with the NRC to review the alternative.

Ref: JLD-ISG-2013-02, JLD-ISG-2015-01 Compliance will be attained for PNPS 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 Hardened Containment Vent System (HCVS) will be comprised of installed and portable equipment and operating guidance:

• Severe Accident Wetwell Vent (SAWV) - Permanently installed vent from the Torus to the Main Plant Stack.

• Severe accident Water Addition (SAWA) - A combination of permanently installed and portable equipment to provide a means to add water to the 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 2Q2017.

• 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 2Q20 19.

If deviations are identified at a later date, then the deviations will be communicated in a future 6 month update following identification.

State Applicable Extreme External Hazard from NEI 12-06, Section 4.0-9.0 List resultantdetermination of screened in hazardsfrom the EA-12-049 Compliance.

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

• Seismic, Snow, Ice and Extreme Cold, High Wind, Extreme High Temperature The following extreme external hazards screen out for PNPS:

• External Flooding Key Site assumptions to implement NEi 13-02 HCVS, Phase 1 and 2 Actions.

Provide key assumptions associatedwith implementation of HCVS Phase 1 and Phase 2 Actions Ref: NET 13-02, Revision 1, Section 2 NET 12-06 Revision 0 Page 5 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 1: General Integrated Plan Elements and Assumptions Mark I/II Generic EA-13-109 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 RCIC or HPCI. (Reference NEI 12-06 3.2.1.3 item 9).

049-5. At Time =0 the event is initiated and all rods inser-t and no other event beyond a common site ELAP is occurring at any or all of the units. (NEI 12-06, section 3.2.1.3 item 9 and 3.2.1.4 item 1-4).

049-6. At Time = 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> an ELAP is declared and actions begin as defined in EA-12-049 compliance.

049-7. DC power and distribution can be credited for the duration determined per the EA-1 2-049 (FLEX) methodology for battery usage, with capacity greater than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. This assumption applies to the water addition capability under SAWA/SAWM. The power supply scheme for the HCVS shall be in accordance with EA-13-109 and the applicable guidance. (NEI 12-06, section 3.2.1.3 item 8).

049-8. Deployment resources are assumed to begin arriving at Time = 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and fully staffed by 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

049-9. All activities associated with plant specific EA-12-049 FLEX strategies that are not specific to implementation of the HCVS, including such items as debris removal, communication, notification, 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)(HCVS-FAQ-1 1).

Applicable EA- 13-109 generic 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. 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 SAWA/SAWM because SAWA equipment needs to be connected and placed in service within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 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 t~o prevent. (Reference NEI 13-02 section 2.3.1).

Page 6 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 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, valving-in nitrogen bottles) are acceptable to obtain HCVS venting dedicated functionality (Reference HCVS-FAQ-0 1).

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 <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> from the time of the loss of RPV injection and will require more than minimal operator action, but these actions are in areas that are accessible and well shielded from radiological effects.

109-07. IICVS 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 White Paper HCVS-WP-0 1).

This assumption does not apply to Phase 2 SAWA/SAWM 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 MAAIP Endorsement ML13190A201) Additional analysis using RELAP5/MOD 3, GOTHIC, PCFLUD, LOCADO SE 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 drywell temperature response to SAWA under severe accident conditions.

109-09. NRC Published Accident evaluations (e.g. SOARCA, SECY-12-0 157, and NUREG 1465) as related to Order EA-13-109 conditions are acceptable as references. (Reference NEI 13-02 section 8).

109-10. Permanent modifications installed or planned per EA- 12-049 are assumed implemented and may be credited for use in EA- 13-109 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/SAMG procedure change process. This assumption does not apply to Phase 2 SAWM because SAWM is not part of Revision 3. (Reference to 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 3-109 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 10OCFR50 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-0 1 and HCVS-FAQ-09).

109-13. The Suppression Pool / Wetwell of a BWR Mark I 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 NEI 13-02 Rev 1, §I.1.3).

109-15. The Severe Accident impacts are assumed on one unit only due to the site compliance with NRC Order EA-1 2-049. However, each BWR Mk I and II under the assumptions of NRC Order EA-1 3-109 ensure the capability to protect Containment exists for each unit (HCVS-FAQ-1). This is further addressed in HCVS-FAQ-l10.

Plant Specific HCVS Related Assumptions/Characteristics:

None.

Page 7 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Providea s'equence of events ~and identify any time or environmental constraint, required for success includin g the blasis for the constrai~nt. ,, , ' / ,i, ,: i" , * - ;  !

HCVS Actions that have a time constraint to be successful should be identified with a technical basis and ajustification 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 ofHigh 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 attached sequence of events timeline (Attachment 2A)

Ref: EA-13-109 Section 1.1.1, 1.1.2, 1.1.3 I NEI 13-02 Section 4.2.5, 4.2.6. 6.1.1 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

• Provide a sequence.e of events sand identify an y;tire or enwironmental constraint ,requiredfor success icluding the,*

Refer to the EA-1 3-109 Phase 1 Overall Integrated Plan.

Provide :Details onthe Vent ,characteristics:s ,*:  : ' *: **;!*  !

Provide Details on the Vent characteristics Vent Size and Basis (EA-13-109 Section 1.2.1 /NEI13-02 Section 4.1.1)

UWhat is the plants licensedpower? Discuss any plansfor possible increases in licensedpower (e.g. MUR, EPU).

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

Vent Capacity (EA-13-109 Section 1.2.1/INEI113-02 Section 4.1.1)

Indicate any exceptions to the 100 decay heat removal criteria, including reasonsfor the exception. Provide the heat capacity of the suppressionpool in terms of time versus pressurizationcapacity, assuming suppressionpool is the injection source.

Vent Path and Dischargie (EA 109 Section 1.1.4, 1.2,2/NEI13-02 Section 4.1.3, 4.1.5 and Appendix FIG)

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

Power and Pneumatic Supply Sources (EA-13-109 Section 1.2.5 & 1.2.6/INEI 13-02 Section 4.2.3, 2.5, 4.2.2, 4.2.6, 6.1)

Provide a discussion of electricalpower requirements, including a description of dedicated24 hourpower supply from permanently installed sources. Include a similardiscussion as abovefor the valve motive force requirements. Indicate the area in the plantfrom where the installed/dedicatedpower and pneumatic supply sources are coming.

Page 8 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Indicate the areas where portable equipment will be staged after the 24 hourperiod, 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 Control Panels (EA 109 Section 1.1.1. 1.1.2, 1.1.3, 1.1.4, 1.2.4, 1.2.5/ NEIJ13-02 Section 4.1.3, 4.2.2, 4.2.3, 4.2.5, 4.2.6, 6.1.1 and Appendix F/G)

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

Hvdrogien (EA-13-109 Section 1.2.10, 1.2.11, 1.2.12 /NEI 13-02 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 offlammable gases, clearly demarcating the 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 /NEI 13-02 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 interfacing valves or Appendix J type testingfeatures?

Prevention of InadvertentActuation (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.

Monitoringof HCVS (Order Elements 1.1.4, 1.2.8, 1.2.9/NE113-02 4.1.3, 4.2.2, 4.2.4, and Appendix FIG)

Provides a description of instruments used to monitor HCVS operationand effluent. Powerfor an instrument will require the intrinsically safe equipment installed as part of the power sourcing.

Component reliable and ruggj~ed performance (EA-13-109 Section 2.2 /NEI 13-02 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 instrumentation that are not requiredto be seismically designed by the design basis of the plant should be designedfor reliable and ruggedperformance that is capable of ensuringHC VS functionalityfollowing a seismic event. (Reference ISG-JLD-201201 and ISG-JLD-2012-03for 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 NE1 12-0 6 as endorsed by JLD-ISG-12-Olfor OrderEA-12-049.

Use of instruments and supportingcomponents with known operatingprinciples that are supplied by manufacturers with commercial quality assuranceprograms, such as IS09001. The procurement specifications shall include the seismic requirements and/or instrument design requirements, and speciify the need for commercial design standards and testing under seismic loadings consistent with design basis values at the instrument locations.

Demonstration of the seismic reliabilityof the instrumentation through 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 IEEE Standard 344-2004, "IEEERecommended Practice Page 9 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent for Seismic Qualification of Class JE Equipmentfor NuclearPower GeneratingStations, " or a substantiallysimilar industrialstandardcould be used.

Demonstration that 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 that performedfor the plant licensing basis.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Page 10 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent

~Part 2 Boundary Conditions for WW 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 descri~ption of the venting actionsforfirst 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment including station modifications that areproposed.

Ref: EA-13-109 Section 1.2.6 / NEI 13-02 Section 2.5, 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

• * .... Greater Than 24 Hour CoigDetail , °°'*

Provide a general descri~ption of the venting actionsfor greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> usingportable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 / NEI 13-02 Section 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

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

Provide a brief description of Procedures I Guidelines:

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

NET 13-02 §6.1.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Identify modifications."

List modifications and describe how they support the HCVS Actions.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Key Venting Parameters:

List instrumentation creditedfor 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).

Page 11 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary conditions for Wetwell Vent

:" Part 2 Boundary"Conditions for WW Vent:....BEE Venting Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Notes: For the BDBEE Case #1 where the FLEX Strategy is successfully implemented, Wetwell venting is initiated at 16 Hours after Shutdown when or before the Suppression Pool exceeds 281 0 F.

Part 2: Boundary Conditions for Wetwell Vent

,,,,* :Part 2, Boundary Conditions for WW Vent: Severe Accident Venting,,,:: *;

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

Ref: EA-13-109 Section 1.2.10 / NET 13-02 Section 2.3 o First 24Hur Coping Detail

• Provide a general description of the venting actionsfor first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment includingstation modifications that areproposed.

Ref: EA-13-109 Section 1.2.6 / NET 13-02 Section 2.5, 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

• Details:

Provide a general descriiption of the venting actionsfor greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> usingportable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 1 NET 13-02 Section 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

" First 24 Hour Coping Detail Provide a brief description of Procedures / Guidelines:

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

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Page 12 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Part 2 Bondary Conditions for WW Vent: Severe Accident Venting Identify modifications."

List modifications and describe how they support the HCVS Actions.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

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).

Refer to the EA- 13-109 Phase 1 Overall Integrated Plan.

Notes: For the postulated Short-Term Severe Accident Case #2B (refer to EA-13-109 Phase 10OP), the Containment Maximum Allowable Working Pressure (MAWP) 62 PSIG Limits are not exceeded when the FLEX injection is initiated by 8 Hours, thereby preventing Containment failure and cooling the overheated core debris, with Wetwell Venting shortly thereafter (at 10 Hours) when Torus Bottom Pressure is at or above the PCPL. It should be considered that, as soon as H2 gas evolution begins and the Torus Bottom Pressure approaches the PCPL value of 60 psig, that Wetwell Venting will be initiated and will mitigate the peak pressure that occurs with continued H2 generation.

Page 13 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent S Part 2 Boundary Conditions for WW Vent: HCVS Su~pport 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. Identify 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 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

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 / NEI 13-02 Section 2.5, 4.2.2, 4.2.4, 6.1.2 Refer to the BA-i13-109 Phase 1 Overall Integrated Plan.

D...etails ..

Provide a brief description of Procedures IGuidelines:

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

Refer to the EA* 13-109 Phase 1 Overall Integrated Plan.

Identify modifications:

List modifications and describe how they support the HCVS Actions.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Page 14 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent

,Part 2 Boundary Conditions fo)r WW Vent: HCVS Support Equipment Functions 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).

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Notes: The HCVS Torus Vent at PNPS includes an 8" Air-Operated Butterfly Valve AO-5025 capable of venting the Wetwell (Torus) airspace through an 8" branch line between the two Primary Containment Isolation Valves (PCTVs)

AO-5042A & B from 20" Torus Penetration X-227. The HCVS Torus Vent flow path via AO-5042B & AO-5 025 cornects to the 20" discharge line downstream of the Standby Gas Treatment System (SGTS) filter trains. The vent flow path is isolated from the SGTS by Air-Operated Discharge Valves AO-N-108 & 112 on the SGTS outlet where the vent 8" piping connects to the 20" discharge piping to the plant's Main Stack that includes a buried piping run from the plant out to the Main Stack.

Page 15 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary Conditions for WW Vent: HCVS Venting Portable. Equipment, Deployment*

Provide a general descrijption of the venting actions usingportable equipment including modifications that areproposed to maintain and/or support safety functions.

Ref: EA-13-109 Section 3.1 / NET 13-02 Section 6.1.2, D.1.3.1 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Provide a brief description of Procedures / Guidelines:

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

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

THCVS Actions Modifications Protection of connections Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Notes: A condensate drain trap, manual isolation valves, and flex hose quick-connect fittings have been installed downstream of SGTS Piping Drain Valve 44-HO-i 14 as part of the FLEX modifications. Prior to venting, a pre-staged flexible hose is connected to this fitting and routed to the Torus Room to drain condensate from the vent pipeline.

Page 16 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3: Boundary Conditions for EA-1 3-1 09, Option B.2 General:...

Licensees that use Option B.] of EA-13-109 (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-13-] 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 Part2 apply to all of thefollowing:

This Partis divided into the following sections."

3.1.' Severe Accident Water Addition (SA WA) 3.1.A: Severe Accident Water Management (SA WMV) 3.1.B: Severe Accident DW Vent (545 degF)

Provide a se'quence of events and identify any time constraint requi~red for success including the basis

'for the time* constraint. " ': " * '  :

SA WA and SA WM or SAD V Actions 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 HC VS part of this template need not be repeated here.

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

• Electricalgenerators 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 SA WA are those actions needed to transport, connect and startportable 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 instrumentation should 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 MCR using control switches. In addition, HCVS operation may occur at the ROS.

Timelines (see attachments to the Phase 1 OIP) were developed to identify required operator response times and actions.

Page 17 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA Tabl~e 3.1 - SAWA Manual ACtions ...

Primary Action Primary Location / Component Notes

1. Establish HCVS capability in U MCR or ROS U Applicable to SAWA/SAWM accordance with Part 2 of the strategy Phase 1 OWP for this Order.

2. Connect FLEX Pump discharge to U HPCI/RCIC connection is the U No hose connections within the FLEX injection piping. primary connection point via Reactor Building are required for external connection to the RPV make-up.

CST. Same connection as FLEX, external to Reactor Building. RHR is the backup and is in the Auxiliary Bay Building.

3. Connect FLEX Pump to water U] Primary connection is the U The location of this source, as well source. normal UIHS intake water as the location of the FLEX Pump, source. is not challenged by severe accident radiological conditions.

4. Power SAWA/HCVS components U One FLEX Portable 480 VAC U No changes required to the with EA-12-049 (FLEX) 3-PH 150 kW Diesel original EA-12-049 strategy.

generator. Generator (DG) will normally be pre-staged in the Turbine Building Truck Lock, which is adjacent to the AC Switchgear and DC System Battery Rooms. This DG is thereby capable of early deployment (within 4 Hours) during any Station Black-Out (SBO) and is capable of maintaining both 125 VDC Battery Divisions, and the 250 VDC Battery, charged and operating indefinitely.

There are additional 86 kW DGs in the dual FLEX Storage sites that are deployable within 6 Hours to perform the same functions.

Page 18 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA

5. Inject to RPV using FLEX Pump U SAWA flow control will be U] Initial SAWA flow rate is (diesel). provided by variable speed 300 gpm per Calculation M 1380 pump controller and by (see Phase 10GIP).

throttling valves at a Strainer Cart; both of which are outside Rx Bldg.

6. Monitor SAWA indications. U] Total flow and SFP flow U] Strainer Cart is outside reactor meters are included in the building and is not challenged by Strainer Cart. severe accident radiological K Containment parameters conditions.

monitored at MCR.

7. Use SAWM to maintain A MCR for indication

• Monitor DW pressure and availability of the Torus Vent U FLEX Pump location for flow Wetwell level in MCR (Part 3.1.A). control.

• Control SAWA flow with variable speed pump controller and by throttling valves at the Strainer Cart as-needed.

Discussion of timeline SAWA identified items HCVS operations are discussed under Phase 1 of EA-13-109 (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-12-049 conditions after RPV level lowers to 2/3 core height are consistent with the radiological conditions assuming permanent Containment shielding remains intact. All other actions required are assumed to be in-line with the FLEX timeline submitted in accordance with the EA-12-049 requirements.

• 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 operating requirementsfor 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 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, as is required to be considered by EA-l13-109 regardless of the adequacy of the FLEX Strategy to prevent such core damage. The SAWA Strategy includes both portable and installed equipment that is also used for the FLEX Strategy, i.e., SAWA utilizes the same injection equipment and methods as FLEX and may be used to recover from any failure to initially implement the FLEX Strategy, or utilize alternative but equivalent equipment if needed.

Page 19 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA The motive force equipment needed to support the SAWA strategy shall be available prior to T = 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 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. Backflow from the reactor/Containment through the FLEX Pumps is prevented by check valves in the RCIC/HPCI system.

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

T <1 hr:

• No evaluation required for actions inside the Reactor Building for SAWA. Expected actions are:

o Begin preparations to connect SAWA hose to the primary injection point, CST, outside the Reactor Building. Any actions performed inside the Reactor Building will be for evaluation of conditions (depending on the BDB Event) or preparatory activities in well shielded normally accessible areas of Secondary Containment that will be at effectively normal radiation dose rates. There will be no unusual restrictions imposed on Reactor Building access by the FLEX Strategy, any restrictions will be based on actual dose rates.

T= 1 - 8hrs:

• Evaluation of core gap and early in-vessel release impact to Reactor Building access for SAWA will be performed as-needed. It is assumed that Reactor Building access is limited due to the source term at this time unless otherwise noted. The FLEX, HCVS, and Severe Accident strategies anticipate or plan activities only in readily accessible areas of Secondary Containment. These areas are well shielded and contain the alternate locations for instrument indications and backup Nitrogen (N2) supplies for HCVS and Safety-Relief Valve (SRV) operation. There are no required activities in the Torus Compartment, RHR Quad Rooms, TIP Room, or other high radiation dose areas. Areas that may have elevated dose rates following core damage or RPV breach are only considered accessible for potential activities early in the ELAP, when dose rates are still in the normal range. This includes localized areas that have line-of-sight exposure to HCVS vent piping. Expected actions are:

o Same as Table 2-1 "HCVS Operator Manual Actions" in Phase 10OP.

• Connect FLEX Pump to water supply at normal UHS intake water source (Step 3 of Table 3.1).

• Establish electrical power to HCVS and SAWA using EA-12-049 generator (Step 4 of Table 3.1).

• Establish initial flow of 300 gpm to the RPV using SAWA systems (Step 5 of Table 3.1).

T _<8 -24 hrs:

• Continue injection for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after SAWA injection begins at initial SAWA rate.

T >24 hrs:

• Proceed at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to MDRIR-based SAWM injection rates - SAWM actions (Part 3.1 .A)

(Step 7 of Table 3.1 above).

Page 20 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA Provide a general description of the SA WA actionsfor greaterthan 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> usingportable and installed equi~pment including station mocifications that are proposed.

Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3/ NET 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).

Details of Design Characteristics/Performance Specifications SA WA shall be capable ofproviding an RPV injection rate of 300 gpm within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of a loss of all RaPV injection following an ELAP/Severe Accident. SA WA shall meet the design characteristicsof the HCVS.

Ref: EA-13-109 Attachment 2, Section B.2.1, B.2.2, B.2.3/ NET 13-02 Section 1.1.4 Equipment Locations/Controls/Instrumentation PNPS has performed a site specific evaluation to justify the use of a lower site unique initial SAWA flow rate.

Consequently, PNPS will assume an initial flow rate of 300 gpm. This initial flow rate will be established within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the loss of all RPV injection following an ELAP/Severe Accident and will be maintained for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> before reduction to the flow rate that allows continued flooding of the RPV & DW Core Debris at the Minimum Debris Retention Injection Rate (MDRIR) based flow rate with only Wetwell venting.

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 ERO dose and plant safety guidelines for temperature and humidity.

The flow path will be from the FLEX Pump suction at the UH1S intake, through the FLEX Pumps and associated hoses and Strainer Cart to the connection point at the CST Vault Backflow from the Reactor / Containment through the FLEX Pumps is prevented by check valves in the RCIC / HIPCI Systems.

DW pressure and Wetwell level will be monitored and flow rate will be adjusted by adjusting the variable speed engine-driven FLEX Pump and throttling the manual valves located on the SAWA Strainer Cart. Communication will be established between the MCR and the SAWA flow control location.

The FLEX Pump suction source is a significant distance from the discharge of the HCVS pipe (Main Plant Stack) with substantial structural shielding and distance between the HCVS pipe and the pump deployment location. FLEX Pump and diesel driven generator refueling will also be accomplished using portable transfer pumps and truck-mounted fuel dispensing tanks.

Initial evaluations for projected SA conditions (radiation / temperature) 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).

Page 21 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan December 2015 Part 3.1: Boundary Conditions for SAWA DC-powered electrical equipment and instrumentation will be powered from the battery chargers that are repowered from the EA- 12-049 generator(s) to maintain the battery capacities during the Sustained Operating period and 120 VAC powered instrumentation, including the Post-Accident Monitoring (PAM) System, will be repowered directly from the same generators.

Parameter Instrument Location Power Source / Notes Wide Range Primary Containment Pressure MCR Panels Repower via EA-12-049 (0 to 225 psig) 120 VAC PI-1001-600A/B C170/C171 FLEX Diesel Generator Panel Y3/Y4 Torus Water Level MCR Panels Repower via EA-12-049 (0 to 300 inches) LI-1001-604A/BC70C1FLXDelGnrao 120 VAC Y3/Y4C1017FEXDelGnrao FLEX Pump Flow Battery Operated (one AW FlwIndicator / Totalizer FLXSrie at year replaceable Li-Ion)

The instrumentation and equipment being used for SAWA and supporting equipment has been evaluated to perform for the Sustained Operating period under the expected radiological and temperature conditions.

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. The connection for the FLEX Pump injection is protected by the CST Vault Missile Protection Enclosure. Portable equipment used for SAWA implementation will meet 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 / NEI 13-02 Section 1.3, 6.1.2

• Connect FLEX Pump discharge to CST that connects with RCIC / HIPCI.

• Power SAWA / HCVS components with EA-12-049 (FLEX) generator using FLEX procedures.

• Start FLEX Pump to establish SAWA flow.

• Adjust flow rate using skid mounted flow indicator and variable speed FLEX Pump Page 22 of 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA Identify modifications:

List modifications 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 None.

Component Qualifications:

State the qualification usedfor equipment supportingSA WA Ref: EA-13-109 Attachment 2, Section B.2.2, B .2.3 I NEI 13-02 Section 1.1.6 Permanently installed plant equipment shall meet the same qualifications as described in Part 2 of the Phase 10OIP.

Temporary/Portable equipment shall be qualified and stored to the same requirements as FLEX equipment as specified in NEI 12-06 Rev 0.

Notes: The postulated Short-Term STSBO Severe Accident scenario Case #2B (refer to EA-13-109 Phase 10OIP),

includes the immediate or early failure of the steam-driven RCIC & HPCI Systems and results in the most rapid core overheating, damage, and RPV breach, which occurs at 8.2 Hours after Shutdown. This allows sufficient time for the FLEX Low Pressure Injection Source to be deployed and begin RPV injection at 300 GPM for RPV and core debris cooling while venting is initiated at the PCPL with the Wetwell at or above 250°F due to the combination of steam and Hydrogen (H2) gas pressure from the core overheating. The 300 GPM injection is continued until the Wetwell is cooled below 250°F, at which time the FLEX injection rate is reduced from 300 GPM to the SAWMV injection rates that conservatively bounds the EOP Minimum Debris Retention Injection Rate (MIDRIR) which maintains the core debris completely cooled while preserving the ability to continue Wetwell Venting for Containment Heat Removal and purging of the steam-diluted Hydrogen gas.

Page 23 of 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.,tA: Boundary Conditions for SAWA/SAWM Time periods for maintaining SAWM actions such that the WW vent remains available SA WM iActions supportingSA conditions that have a time constraint to be successful should be identified with a technical basis and a justificationprovided that the time can reasonably be met (for example, a walkthrough of deployment). Actions already identified under the HC VS part of this template need not be repeated here.

There are three time periodsfor the maintaining SA WM actions such that the Wetwell 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 modifications or procedures is necessary with respect to how alternate Containment heat removal will be provided.

• ] SAWM can be maintainedfor at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, but less than 7 days before DWpressure reaches PCPL or design pressure, whichever is lower.

o Under this approach, a functional 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 and pressure 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 <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before DW pressure reaches PCPL or design pressure whichever is lower.

o Under this approach, a functional 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, physicalplant modifications and detailedprocedures are required to be implemented to insure achieving alternateContainment heat 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 drywell vent to maintain pressure below PCPL.

Basis for SAWM time frame .. . . ... *.. ,,...  ; ... ..

Option 1 - SAWM can be maintained greater than or equal to 7 days:

PNPS has performed a site specific evaluation to determine the initial SAWA flow rate. PNIPS will establish an initial flow rate of 300 gpm.

This initial flow rate will be established within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the loss of all RPV injection following an ELAP/Severe Accident and will be maintained for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> before reduction to the flow rate that allows continued flooding of the RPV & DW Core Debris at the Minimum Debris Retention Injection Rate (MDRIR) based flow rates with only Wetwell Venting for the duration of the event.

Instrumentation relied upon for SAWM operations is Drywell Pressure, Torus level, and SAWA flow. Except for SAWA flow, SAWM instruments are initially powered by station batteries and then by the FLEX (EA- 12-049) generator which is placed in-service prior to core breach. 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 Page 24 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1 oA: Boundary Conditions for SAWAISAWM 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. (C.7.l1.4.2, C.8.3.l)

Torus level indication is maintained throughout the Sustained Operation period, so the HCVS remains in-service. The time to reach the level at which the Torus Vent must be secured is >7days using SAWM flowrates (C.6.3, C.7. 1.4.3).

Table 3.1 .B -' SAWM Manual Actions Primary Action Primary Location / Notes Component

1. Lower SAWA injection o Containment parameters U Control to maintain Containment and rate to control Torus monitored in the MCR Torus parameters to ensure Torus vent Level and decay heat

• Flow control at FLEX remains functional.

removal Pump and Strainer Cart U MDRIR-Based SAWMV flow rate minimum capability is maintained for greater than 7 days

• SAWA/SAWM flow rates will be controlled using variable speed pump controller at the Pump Skid and by throttling valves at the Strainer Cart.

2. Control to SAWM

• Flow control at FLEX U SAWM flow rates will be monitored using flowrate for Containment Pump and Strainer Cart the following instrumentation control /decay heat o SAWA Flow removal o Torus Level a Containment Pressure

• SAWM flow rates will be controlled using a variable speed pump controller at the Pump Skid and by throttling valves at the Strainer Cart.

3. Establish alternate source a Yard U >7 days of decay heat removal

4. Secure SAWA / SAWM

• FLEX Pump U When reliable alternate Containment decay

• IFLEX Strainer Cart heat removal is established.

SAWM Time Sensitive Actions Time Sensitive SAWMI Actions:

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

Page 25 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1.A: Boundary Conditions for SAWA/SAWM 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 / NEI 13-02 Appendix C It is anticipated that SAWMV 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment including station mnodifications that are proposed.

Given the initial conditionsfor EA-13-109:~

[] BDBEE occurs with ELAP

• ] Failure of all injection systems, includingsteam-powered injection systems Ref: EA-13-109 Section 1.2.6, Attachment 2, Section B.2.2, B.2.3 1 NET 13-02 2.5, 4.2.2, Appendix C, Section C.7 SAWA will be established as described 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 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, the flow will be reduced while monitoring DW pressure and Torus level. SAWM flowrate can be lowered to maintain Containment parameters and preserve the Tours 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 WA! actionsfor greaterthan 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using portable and installed equipment includingstation modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8, Attachment 2, Section B.2.2, B.2.3 / NET 13-02 Section 4.2.2, Appendix C, Section C.7 SAWMV can be maintained >7 days:

The SAWMV flow strategy will be the same as the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> until 'alternate reliable Containment heat removal and pressure control' is reestablished. SAWM flow strategy uses the SAWA flow path. No additional modifications are being made for SAWM.

Page 26 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1.A: Boundary Conditions for SAWAISAWM

" ' ~ ~~~~Details: ' '.... . .... .

Details of Design Characteristics/Performance Specifications Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NEI 13-02 Section Appendix C SAWM shall be capable of monitoring the Containment parameters (DW pressure and Torus 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 / NET 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 at the SAWA Strainer Cart by a portable flow instrument qualified to operate under the expected environmental conditions. The SAWA flow instrument is battery powered and can operate for one-year on two replaceable Li-Ion batteries. Communications will be established between the SAWM control location and the MCR.

SAWM injection flow rates will be controlled using the variable engine speed pump controller and by throttling valves at the Strainer Cart.

Torus level and DW pressure are read in the Main Control Room using indicators powered by the FLEX DG installed under EA-12-049. These indications are used to control SAWM flowrate to the RPV.

Key Parameters:

List instrumentation creditedfor the SA WivlActions.

Parameters used for SAWMV are:

[] DW Pressure

• ] Torus Level

[] SAWM Flowrate The Drywell Pressure and Torus Level instruments are qualified to RG 1.97 and are the same as listed in Part 2 of the Phase 10ITP. The SAWM flow instrumentation is portable, included with the FLEX Strainer Cart, and was selected for the expecte~d environmental conditions.

Notes: The SAWA / SAWM Strategy is simplified to the point that it could be successfully implemented using only the SAWM Flowmeters & Totalizers on the FLEX Strainer Cart for at least the initial 7 days.

Page 27 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1°~B: Boundary Conditions for SAWA/SADV

"* '*....  : .. . .Applicability of' WW Desi'gn Consideration s ".; * ". .

This section is not applicable to PNPS.

Ta~ble 3.1.C -: SADV'ManUal Actions * "" .... :; ', °* "

Timneline for SADV SeveeAccident Venting ' ' '

"**, First-24 :Hour Coping Detail ... ... " .. ... t . .. * :

Greaiter Than 2 Hour Copin Detai

".. .De.. tails:tal °"  : " " " ... :"

Page 28 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance Idniyho~h rorm aiccnrlswl em et... ...

Provide a description of the programmatic controls equipmentprotection, storage and deployment and equipment quality addressing the 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-l13-109 and the hazards applicable to the site per Part 1 of this OIP.

o Routes for transporting portable equipment from storage location(s) to deployment areas have been developed.

The identified paths and deployment areas will be analyzed for potential radiation effects to ensure they remain fully accessible during Severe Accidents.

Procedures:

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

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

o appropriate conditions and criteria for use of the HCVS o when and how to place the HCVS in operation,

§ the location of system components,

• instrumentation available,

" normal and backup power supplies,

• directions for sustained operation, including the storage location of portable equipment,

• training on operating the portable equipment, and o testing of portable equipment.

PNPS 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 HCVS/SAWA functionality are applicable in 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:

Page 29 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance o 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 / NET 13-02 Section 6.1.3 Personnel expected to perform direct execution of the H-CVS/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.

Iidentf how the drills anid exercise parameters will be met.:  : * *<*," **.,..i..

Alignment with NEJ113-06 and 14-01 as codified in NTTF Recommendation 8 and 9 rulemaking The Licensee should demonstrate use of the HGCVS/SAWVA/SA WAM system in drills, tabletops, or exercises as follows:

Hardened Containment vent operation on normal power sources (no ELAP).

o During FLEX demonstrations (as required by EA-12-O49. Hardened Containmentvent operation on backup power andfrom primary or alternate location during conditions of ELAP/loss of UHS with no core damage.

System use isfor Containment heat removal AND 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 Containmentheat removal AND Containmentpressure control with potentialfor combustible gases (Demonstrationmay be in conjunction with SAG change).

• Operationfor sustainedperiod with SA WA and SA WM to 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.

Page 30 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance Describe maintenance plan:

Describe the elements of the maintenanceplan

" The maintenanceprogram should ensure that the HCVS/SA WA/SA WM equipment reliability is being achieved in a manner similar to that requiredfor FLEX equipment. Standard industry templates (e.g., EPRI) and associated bases may be developed to define specific maintenance and testing.

o Periodic testing andfrequency should be determined based on equipment type, expected use and manufacturer'srecommendations (furtherdetails are provided in Part 6 of this document).

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

o Preventive maintenance should be determined based on equipment type and expected use. The basis should be documented and deviationsfrom vendor reconumendationsand applicable standardsshould be justifled.

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

• HCVS/SA WA permanent installed equipment should be maintained in a manner that is consistent with assuring that it performs its function when required.

o HCVS/SA WA permanently installed equipment should be subject to maintenance and testing guidance provided to verify properfunction.

• HCVS/SA WA non-installedequipment should be stored and maintainedin a manner that is consistent with assuring that it does not degrade over longperiods ofstorage and that it is accessiblefor periodic maintenance and testing.

Ref: EA-13-109 Section 1.2.13 / NEI 13-02 Section 5.4, 6.2 PNPS will utilize the standard EPRI industry PM process (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.

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

Page 31 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015

-Part 4: Programmatic Controls, Training, Drills and Maintenance Table 4-1: Testing and Inspection Requirements Description Frequency Cycle the HCVS and installed SAWA valves' 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.

Perform visual inspections and a walk down of HCVS Once per every other4 operating cycle.

and installed SAWA components.

Functionally test the HCVS radiation monitor. 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 Once per every other operating cycle.

an 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.

lNot 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.

3Not 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.

Page 32 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance SInterfacing 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 functional testing or system operation that reposition the valve(s) to the HCVS required position will meet this requirement without the need for additional testing.

Notes:

The PCIVs are required for Containment integrity during Modes 1-3 and thus are excluded from EA-1 3-109 testing requirements. These PCIVs are tested per the PNPS design basis requirements to ensure valve operability and leakage tightness.

Page 33 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 5: Milestone Schedule ProVide a milestone schedule ....  :

Provide a milestone schedule. This schedule should include:

o Modifications timeline o 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 order are 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:

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Phase 2 M ilestone 'Schedule:.. . . . .. ..  ;* *,,...., , ......

Phase 2 Milestone Schedule Milestone Target Completion Activity Comments Date Status Submit Overall integrated Implementation Plan Dec 2015 Complete Separate submittal from Phase 1 update Submit 6 Month Status Report June 2016 Submit 6 Month Status Report Dec 2016 Submit 6 Month Status Report June 2017 Submit 6 Month Status Report Dec 2017 Design Engineering On-site/Complete Jan 2018 Not Started Submit 6 Month Status Report Jun 2018 Page 34 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 5: Milestone Schedule Submit 6 Month Status Report Dec 2018 Operations Procedure Changes Developed Dec 2018 Not Started Site Specific Maintenance Procedure Developed Dec 2018 Not Started Training Complete Dec 2018 Not Started Implementation Outage Feb 2019 Not Started Walk Through Demonstration/Functional Test Feb 2019 Not Started Procedure Changes Active Feb 2019 Not Started Submit Completion Report April 2019 Not Started Page 35 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 1: HCVSISAWA Portable Equipment Maintenance / PM requirements List portable equipment The portable equipment listed below supports SAWA/SAWM (Phase 2).

For a list of Phase 1 HCVS Equipment, refer to the Phase 1 Overall integrated Plan and associated 6 month updates FLEX DG (including cable, connectors, etc.) X X 150 & 86 kW Per Response to EA-12=049 DGs FLEX Pump (including dual strainer, X X 300 gpm for Per Response to EA-1 3-1 09 flowmeter, flexible hose, fittings, etc.) first 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> and MDRIR-Based Flowrates for at least the first 7 days Page 36 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2A: Sequence of Events Timeline - HCVS Refer to the EA-13-109 Phase 1 Overall Integrated Plan (page 40 of 58).

Page 37 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2.1 .A: Sequence of Events Timeline - SAWA I SAWM Refer to the EA-13-109 Phase 1 Overall Integrated Plan (Case 2A and 2B Graphs; page 41 and 42 of 58).

Page 38 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 .1 .B: Sequence of Events Timeline - SADV This is not applicable to PNPS.

Page 39 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2.10: SAWA / SAWM Plant-Specific Datum LOWER DRYWELL INSIDE SPHERICAL RADIUS 32 FT

.y 20-INCH DIAMETER HCVS VENT PIPING VERTICAL RISE TO EL 23 FT TIP ROOM REDUCE TO 8-INCH DIAMETER @ EL 28.6 FT LOWER DRYWELL EQUATOR @ EL 29.25 FT INLET TO PCIV &HCVS VALVE STATIONS DW VENT JET DEFLECTOR (81 6 FT 9-INCH DIAMETER DRYWELL VENT LINES TOP OF TORUS @EL 14.50 FT DW VENT C.L

@ EL 1325 FT MAXWATER LEVEL TO VENT 283 INCH @ EL 10.00 FT CL. OF VACUUM BREAKERS @ EL3.58 FT C.L. OF TORUS @ EL (-)0.25 FT NORMAL WATER LEVEL 130 INCH @ EL (-(2.75 FT TORUS WATER VOLUMES:

MAXWATER LEVEL TOVENT

- 1.500,000 GAL CL. OF VACUUM BREAKERS - 1,095.000 GAL iNORMAL WATER LEVEL - 650,000 GAL

• FT MAXNET WATER UP TO VENT - 850.000 GAL WIDE RANGE TORUS LEVEL 0 TO 300 IC

REFERENCES:

IOF TORUS @ EL (-(1500 FT CALCULATION M1380 DRAWINGS:

M23 M8649SH1 NOTE: CALCULATION M1380 CASE 2B SHORT-TERM SBO WITH NO RPV INJECTION FOR 8 HOURS IS THE BOUNDING SA. ANALYSIS.

FLEX SAWA INJECTION @ 300 GPM FROM 8 TO 24 HOURS FOLLOWED BY MDRIR-BASED INJECTION & WETWELL VENTING @ 10 HOURS. C1A1-8 C1A5-I1 C1A50-5 NET TORUS WATER ADDITION AFTER 30 DAYS IS LESS THAN 850,000 GAL WITH WETWELL VENTING ABOVE 220 OEGF. C1A51-7 C1A57-6 C 153 Page 40 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2.1.D: SAWM SAMG Approved Lan~qua~qe The following general cautions, priorities and methods will be evaluated for plant specific applicabilityand incorporatedas appropriateinto the plant specific SAMGs using administrativeprocedures for EPG/SAG change contfrol process and implementation. SAMGs are symptom based guidelines and therefore address a wide variety of possible plant conditions and capabilitieswhile these changes are intended to accommodate those specific conditions assumed in OrderEA-13-109. The changes will lie 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 Language 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 Torus 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 1/1l suppression chamber vent paths, thereby retaining the benefits of Torus scrubbing and minimizing the likelihood of radioactivity and hydrogen release into the Secondary Containment (SAWM).

Page 41 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Methods:

Identify systems and capabilities to add water to the RPV or drywell, 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.

Page 42 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 3: Conceptual Sketches Refer to the EA-1 3-1 09 Phase I Overall Integrated Plan for the following sketches:

Electrical HCVS Electrical Layout Drawing Flow and Control Diagrams P&ID Layout of HCVS Plant Layout HCVS Local Panel HCVS Local Panel (Detail A)

Condensate Drain Hose Connection Standby Gas Treatment System Isolation Additional Phase 2 Sketches:

Sketch 1: FLEX / SAWA Equipment Location Sketch 2: FLEX I SAWA Power Distribution Page 43 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 FLOATING STRAINERS Sketch 1: FLEX / SAWA Equipment Location Page 44 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 PILGRIM FLEX 86KW GENERATOR PILGRIM FLEX 150KW GENERATOR F480VAC OPH (NOTES 1, 2, 3) 7 [ 80VAC3PH (NOTES 1, 2, 3)]

I(T150KW B N, , ,o L j 3OOA~

I ~J PWR D1ST 240/120V L IJ PWR DIST 240/120V FLEX GENERATOR SUPPORTING 125VDC &: 250VDC BATTTERY CHARGERS FLEX GENERATOR SUPPORTING 125VDC BATTTERY CHARGER 120VAC PANEL Y4/Y41 &: BATTERY ROOM FAN 120VAC PANFl Y3/Y31 &: RATTFRY ROOM FAN Sketch 2: FLEX / SAWA Power Distribution Page 45 of 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 4: Failure Evaluation Table Refer to the EA- 13-109 Phase 1 Overall Integrated Plan.

Page 46 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015, Attachment 5: References

1. Regulatory Documents A. Generic Letter 89-16, Installation of a Hardened Wetwell Vent, dated September 1, 1989 B. Order EA-12-049, Mitigation Strategies for Beyond-Design-Basis External Events, dated March 12, 2012 C. Order EA-12-050, Reliable Hardened Containment Vents, dated March 12, 2012

0. Order EA-12-051, Reliable SEP Level Instrumentation, dated March 12, 2012 E. Order EA-1 3-1 09, Severe Accident Reliable Hardened Containment Vents, dated June 6, 2013 F. JLD-ISG-2012-01, Compliance with Order EA-12-049, Mitigation Strategies for Beyond-Design-Basis External Events, dated August 29, 2012 G. JLD-ISG-2012-02, Compliance with Order EA-12-050, Reliable Hardened Containment Vents, dated August 29, 2012 H. JLD-ISG-2013-02, Compliance with Order EA-13-1 09, Severe Accident Reliable Hardened Containment Vents, dated November 14, 2013 I. NRC Responses to Public Comments, Japan Lessons-Learned Project Directorate Interim Staff Guidance JLD-!SG-2012-02: Compliance with Order EA-12-050, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents, ADAMS Accession No. ML12229A477, dated August 29, 2012 J. NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, Revision 1, dated August 2012 K. NEI 13-02, Industry Guidance for Compliance with Order EA-1 3-109, Revision 1, Dated April 2015 L. NEI 13-06, Enhancements to Emergency Response Capabilities for Beyond Design Basis Accidents and Events, Revision 0, dated March 2014 M. NEI 14-01, Emergency Response Procedures and Guidelines for Extreme Events and Severe Accidents, Revision 0, dated March 2014 N. NEI FAQ HCVS-01, HCVS Primary Controls and Alternate Controls and Monitoring Locations

0. NEI FAQ HCVS-08, HCVS Instrument Qualifications P. NEI FAQ HCVS-09, Use of Toolbox Actions for Personnel Q. NEI White Paper HCVS-WP-02, HCVS Cyclic Operations Approach R. NEI White Paper HCVS-WP-04, FLEX/HCVS Interactions S. NUREG/CR-71 10, Rev. 1, State-of-the-Art Reactor Consequence Analysis Project, Volume 1: Peach Bottom Integrated Analysis Page 47 of 50:

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 T. SECY-1 2-01 57, Considerationof Additional Requirements for Containment Venting Systems for Boiling Water Reactors with Mark I and Mark II Containments, 11/26/12 U. PNPS ESAR, Rev. 28, Final Safety Analysis Report V. JLD-ISG-2015-01, Compliance with Phase 2 of Order EA-13-1 09, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions, dated March 2015 W. NEI HCVS-FAQ-10, Severe Accident Multiple Unit Response X. NEI HCVS-FAQ-1 1, Plant Response During a Severe Accident Y. NEI HCVS-FAQ-12, Radiological Evaluations on Plant Actions Prior to HCVS Initial Use Z. NEI HCVS-FAQ-1 3, Severe Accident Venting Actions Validation

2. Standards A. IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1 E Equipment for Nuclear Power Generating Stations,

3. Overall Integrated Plans A. PNPS EA-12-049 (FLEX) Overall Integrated Implementation Plan, Rev 0, February 2013 B. PNPS EA-13-109 (HCVS) Overall Integrated Implementation Plan, Rev 0, June 2014

4. Calculations A. Calculation M1380, Rev. 0, PNPS FLEX Strategy Thermal-Hydraulic Analysis

5. Procedures A. FSG 5.9.2.4, Rev. 0, FLEX Low Pressure Injection - Seawater through CST Inj~ection Point to RPV

6. Engineering Change Packages A. EC-42259, Rev. 0, PNPS FLEX Strategy Master EC For Beyond-Design-Basis External Events (BDBEEs) Diverse & Flexible Coping Strategy (Flex)

Implementation B. EC-45555, Rev. 0, FLEX Alternate Power To 125 VDC and 250VDC Battery Chargers (Base EC)

C. EC-45556, Rev. 0, FLEX Alternative Power To 120 VAC Panels (Base EC)

Page 48 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 6: Changqes/Updates to this Overall Integrated Implementation Plan This Overall Integrated Plan has been updated in format and content for Phase 2 of Order EA-13-109. Any significant changes to this plan will be communicated to the NRC staff in the 6 Month Status Reports.

Page 49 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 7: List of Overall Integrated Plan Open Items Phase 1 and ISE Open Items are addressed as part of the Phase 10OIP updates.

Phase 2 Open Item Action Comment 1 No Open Items Page 50 of 50

ATTACHMENT 3 To PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Responses to Phase 1 Interim Staff Evaluation Open Items (6 pages)

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Response to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The PNPS HCVS is capable of venting the equivalent of (1) percent of licensed/rated thermal power and the Torus is capable of absorbing the decay heat from full power to (1) one percent licensed/rated thermal power to maintain the integrity of primary containment.

Make available for NRC staff audit analyses Calculations M 1387 "Hardened Containment Vent Capacity" and M 1380 demonstrating that HCVS has the capacity to vent "PNPS FLEX Strategy Thermal-Hydraulic Analysis" together validate the the steam/energy equivalent of one (1) percent of vent capacity for 1% licensed/rated thermal power at Containment Design licensed/rated thermal power (unless a lower value is Pressure (56 psig) and at the expected actual peak Wetwell venting justified), and that the suppression pool and the Section 3.2.2.1 conditions (Containment Design Temperature of 281 0F at the Saturation HCVS together are able to absorb and reject decay Section 3.2.2.2 Pressure of 35 psig). The analysis of the Suppression Pool (Torus) heat, such that following a reactor shutdown from capacity, temperature, and overall thermal balance when using Torus full power containment pressure is restored and then Venting for Containment Heat Removal, including reduced venting maintained below the primary containment design capacities at lower pressures and the net change to Torus water inventory, pressure and the primary containment pressure limit, is all included in Calculation M 1380. These Calculations were issued as a part of the PNPS FLEX Modification, Engineering Change (EC) 42259 and associated EC 46812. These documents are available for NRC Review on the ePortal.

EA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pge1o6 Page 1 of 6

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Response to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The PNPS HCVS utilizes the Main Stack for discharge. In accordance with the PNPS FSAR (12.2.1.2) the Main Stack is a PNIPS Class I structure, as part of Secondary Containment System. As noted within the FSAR, portions of the Secondary Containment System are not designated to be functional during or after a tornado and, as such, the Main Stack was designed for the anticipated sustained high wind loads but not specifically Make available for NRC staff audit the seismic anddeindtwthadexrmtoaowndldng 2 tornado missile final design criteria for the HCVS Section 3.2.2.3 Seismic and sustained wind loading are included in the design criteria for stack. Section 3.2.11 the Main Stack and, in this application, the high wind loads were indicated as the controlling parameter for the stack design.

Calculation C15.0.3360 documents a review of the design basis requirements, design criteria, and acceptance criteria for the Main Stack and this analysis was performed to assess the stack to ensure compliance with FSAR design basis requirements. This document is available for NRC Review on the ePortal.

The HCVS Phase 1 design change package, along with supporting calculations, will identify the anticipated conditions during ELAP and a Severe Accident and confirm the capability for operating personnel to Section 3.2.1 safely access and operate controls and support equipment. The FLEX, Sein3.2.2.4 HCVS, and Severe Accident strategies anticipate or plan activities only in Makeavalabe fr NC saffaudt a evluaionof ection3.2.2.5 readily accessible areas of Secondary Containment. These areas are well Makeavalabe NR stff frudi an valatin o Secion3.22.5 shielded and contain the alternate locations for instrument indications and temperature and radiological conditions to ensure Section 3.2.2.1 bcu irgn(2 upisfrHV n aeyRle av SV that operating personnel can safely access and Section 3.2.4.1 bcu irgn(2 upisfrHV n aeyRle av SV operate controls and support equipment. Section 3.2.4.2 operation. There are no required activities in the Torus Compartment, Section 3.2.5.2 RJTR Quad Rooms, TIP Room, or other high radiation dose areas. Areas Secton 32.6 that may have elevated dose rates following core damage or RPV breach are only considered accessible for potential activities early in the ELAP, when dose rates are still in the normal range. This includes localized areas that have line-of-sight exposure to HCVS vent piping.

EA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pge2o6 Page 2 of 6

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp*onse to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The planned HCVS design utilizes the Main Stack as the discharge point.

The top of the Main Stack is at elevation 400 feet. The next highest plant structure is the stack tower structure attached to the Reactor Building. The 4 Prvd ecitoProvde decripionconirmng ofrigta tat heh CVSstack CS Section 3.2.2.3 exhausttower duct.structure The top houses the auxiliaryi of the weather boilerthestack, cap, over and theexhaust ventilation ventilation duct, discargs min t a ointaboe lantstrctues.is at approximately elevation 190 feet. The distance from the vent stack centerline to the centerline of the Reactor, is approximately 700 feet.

Refer to PNPS site drawings FLEX-01, M22, M28, & C332A.

The required instrumentation and controls (existing and new) are identified on page 18 of the PNPS HCVS OIP (June 2014). The existing instrumentation relied upon by HCVS provide indication of DryweUl &

Make available for NRC staff audit descriptions of Wetwell Pressure, Wetwell Level & Temperature, Reactor Pressure and all ad ad cntrls nstumetatin all nstumetatin cntros (xisingandHCVS (xis includn g Section 3.2.2.9 includesValve Position indication Indication. TheTemperature, proposed newSysteminstrumentation of HCVS Effluent Pressure, Flow planned) necessary to implement this order icung& Radiation Dose Rate, and Pneumatic Supply Pressure.

qualification methods. The PNPS HCVS detailed design is currently in progress. The design change package will issue documentation for the qualification of the components required for HCVS.

The proposed HCVS Battery System design criteria includes requirements for a minimum of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of operation with no recharging. The alternate Section 3.2.2.4 power source for the Battery Charger / Power Supply will be provided by a Sectin 3..3.1 FLEX Diesel Generator before the end of the initial 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, which Makeavalabe NR stff fr udi thefinl szin Secion3.23.2 will extend the operation of the HCVS instrumentation indefinitely.

6 evaluation for HICVS batteries/batteryintoFLEXDG charger oadig Section Setio 3.2.4.1 3.24.2 The part PNPS FLEX FLEX of thethe PNPS Generator loading calculation, Modification, PS262, was issued ECs,astoa including incorporation inoFE GlaigScin3242 establish capacity requirements for EC the 42259 FLEX and associated Generators. This calculation. Section 3.2.5.1 document is available for NRC Review on the ePortal. Analyses to Sectin 3..5.2 establish the required capacity of the HCVS Battery System and any Secton 32.6 required updating of the FLEX DG loading calculation will be issued as part of the detailed HCVS Phase 1 design change package.

EA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pae3o6 Page 3 of 6

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp*onse to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response Section 3.2.2.4 Section 3.2.3.1 Calculation M1386 "HCVS Vent Valves AO-5025 and AO-5042B Backup Section 3.2.3.2 N2 System" and Drawing C3102 were issued as a part of the PNPS FLEX Makte aCVa iablefrnCstf anudaic yte douentaion Section 3.2.4.1 Modification, EC 42259 and associated EC 46820, to establish theHCVS 7 ontroen th HCSneuati sytemdesgn Section 3.2.4.2 Nitrogen System design. These documents are available for NRC Review including sizing and location. Section 3.2.5.1 on the ePortal.

Section 3.2.5.2 Section 3.2.6 Make available for NRC staff audit the descriptions ofmlocal)condtionsp(temperaureg rLAditoand svreto ... The PNPS HCVS detailed design change package, along with supporting humiity antcipteddurig EAP nd sver Setion3.22.3 calculations, will finalize the anticipated conditions during ELAP events accident for the components (valves, Section 3.2.2.5 and a Severe Accident and confirm the capability of the components to 8 instrumentation, sensors, transmitters, indicators, Section 3.2.2.9 pefrthifucon.TeEwllasisedcmnainaddsus electronics, control devices, etc.) required for HCVS Sectionpefrthifucon.TeEwllasisedcmnainaddsus venting including confirmation that the components 3.2.2.10 the qualification of any new components required for HCVS.

are capable of performing their functions during ELAP and severe accident conditions.

Makeavalabl NRCstaf auitfo ocumntaionThe EP-Communications (EP-Comms) design change package has been that demonstrates adequate communication between implemented in support of the PNPS FLEX modifications. The HCVS 9 the remote HCVS operation locations and HCVS Section 3.2.2.5 design change package will evaluate the EP-Commns equipment required to decision makers during FLAP and severe accident support the HCVS. There are no significant changes anticipated for the conditions. EP-Comms capabilities that were established for the FLEX Strategy.

Calculation Ml1388 "HCVS Unintended Cross Flow Evaluation" was Make available for NRC staff audit descriptions of issued as part of the PNPS FLEX Modification, EC 42259 and associated design details that minimize unintended cross flow EC 46812, to address this requirement for the FLEX Strategy. The PNPS 10 of vented fluids within a unit including: the final Section 3.2.2.7 HCVS detailed design is currently in progress. This calculation will be method to isolate HCVS from SBGT, all interfacing updated as-needed for Severe Accident/FLAP conditions as part of the discharges to the plant stack, and control of all HCVS design change package. This document is available for NRC penetrations to the HCVS envelope. Review on the ePortal.

EA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pae4o6 Page 4 of 6

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp*onse to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The PNPS HCVS detailed design is currently in progress. The PNPS FLEX, HCVS, and Severe Accident mitigation strategies prevent exceeding the design capabilities of Primary Containment by initiating Torus Venting at or before exceeding the Torus Bottom Pressure Primary Containment Pressure Limit (PCPL) value of 60 PSIG. Calculation M1380 "PNPS FLEX Strategy Thermal-Hydraulic Analysis" evaluates the Severe Accident Hydrogen (H2) production and shows that saturated steam temperature & pressure will combine with the H2 and N2 gas pressurization up to the Maximum Allowable Working Pressure (MAWP) for the Torus at 62 psig for the Short-Term Station Blackout (STSBO)

Case, which is based on the minimum time before core damage and RIPV Make available for NRC staff audit documentation breach. There is a potentially higher peak pressure of 82 psig for the of an evaluation verifying the existing containment Long-Term Station Blackout (LTSBO) Case, where core damage and 11 isolation valves, relied upon for the HCVS, will open Section 3.2.2.9 overheating occur later, after some time period on the order of 8 eight under the maximum expected differential pressure hours or longer during which there is successful operation of RCIC or during BDBEE and severe accident wetwell venting. HPCI for core cooling, then the H2 gas pressure and N2 gas pressure, together with the saturated steam pressure at that point in time, can significantly exceed the Torus Bottom Pressure PCPL value of 60 PSIG when the Wetwell is at 281°0F, although the Drywell Head Leakage Pressure Limit of 80 PSIG is not exceeded if Wetwell Venting is initiated at that time, which would be expected based on the use of EOPs or SAGs.

It is considered that, as soon as H2 gas evolution begins and the Torus Bottom Pressure approaches the PCPL value of 60 psig, Wetwell Venting will be initiated and will mitigate the peak pressure that occurs with continued H2 generation. This document is available for NRC Review on the ePortal.

EA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pae5o6 Page 5 of 6

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp3onse to Phase 1 Interim staff Evaluation Open Items 01 # Action ISE Section PNPS Response The HCVS will be utilized to maintain the pressure within the containment Primary Containment Pressure Limit (PCPL), in accordance with EOPs and SAGs. This will minimize any leakage through containment Provide a description of the strategies for hydrogen penetrations and associated primary containment isolation valves. The 12 cntrlthtatpoental iniize or ydrgengasSecion3.22.6 HCVS piping is of welded construction and the number of boundary migratiotand mingriesst the roeactiaorbuidiognga orton32.. valves is minimized. Potential leakage from HCVS boundary isolation other buildings, valves will be addressed for Severe Accident conditions including consideration of hydrogen and combustible gases and radiological isotopes as part of the HCVS design change package. The PNPS HCVS detailed design is currently in progress.

References to be placed on ePortal:

[1] Calculation M1380 Rev 0 PNPS FLEX STRATEGY THERMAL-HYDRAULIC ANALYSIS

[2] Calculation M1386 Rev 0 HCVS Vent Valves A0-5025 and A0-5042B Backup N2 System

[3] Calculation M1387 Rev 0 Hardened Containment Vent Capacity

[4] Calculation M1388 Rev 0 HCVS Unintended Cross Flow Evaluation

[5] Calculation C1 5.0.3360 Rev 1 MAIN STACK STRUCTURAL EVALUATION

[6] Calculation PS262 Rev 0 FLEX Diesel Generator Loading

[7] Drawing FLEX-01 Rev 0 PNPS FLEX EQUIPMENT LAYOUT

[8] Drawing M22 Rev7 EQUIPMENT LOCATION REACTOR BUILDING SECTION CC

[9] Drawing M28 Rev 8 EQUIPMENT LOCATION MAIN STACK & FILTER BUILDING PLANS & SECTIONS

[10] Drawing C332A Rev 10 MISCELLANEOUS STRUCTURES STACK PLAN, ELEVATION & DETAILS

[11] Drawing C3102 Rev 0 (EC46820) N2 CYLINDER SUPPORT BACKUP N2 SUPPLY TO AO-5025 & AO-5042B FA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pae6o6 Page 6 of 6

i Nuclear Power Station Pilgrigym Entergy Nuclear Operations, Inc.

600 Rocky Hill Road Plymouth, MA 02360

• ) John A. Dent, Jr.

Site Vice President December 17, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852

SUBJECT:

Pilgrim Nuclear Power Station's Third Six-Month Status Report, Phase 2 Overall Integrated Plan, and Responses to Phase 1 Interim Staff Evaluation Open Items 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)

Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35

REFERENCES:

1. NRC Order Number EA-1 3-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions,"~

dated June 6, 2013 (Accession No. ML13143A334).

2. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with Order EA-13-1 09, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated November 2013 (Accession No. ML13304B836).

3. NRC Endorsement of Industry "Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-1 3-1 09), Rev 0" (Accession No. ML14128A219).

4. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA-1 3-1 09, To Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated November 2013.

5. Entergy's Phase 1 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-1 3-1 09),

dated June 30, 2014.

LETTER NUMBER 2.15.082

Dear Sir or Madam:

On June 6, 2013, the U. S. Nuclear Regulatory Commission (NRC) issued an order (Reference

1) to Entergy Nuclear Operations, Inc. (Entergy). Reference 1 was immediately effective and directs Entergy to install a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris. Specific requirements are outlined in Attachment 2 of Reference 1.

PNPS Letter 2.15.082 Page 2 of 3 Reference I required submission of a Phase 1 overall integrated plan pursuant to Section IV, Condition D. Reference 3 endorses industry guidance document NE! 13-02, Revision 0 (Reference 4) with clarifications and exceptions identified in Reference 2. Reference 5 provided the Entergy overall integrated plan.

Reference 1 requires submission of a status report at six-month intervals following submittal of the overall integrated plan. References 2 and 4 provide direction regarding the content of the status reports. The purpose of this letter is to provide the third six-month status report pursuant to Section IV, Condition D, of Reference 1, that delineates progress made in implementing the requirements of Reference 1. The attached status report (Attachment 1) provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any.

Reference I also requires submission of an overall integrated plan (QIP) by December 31, 2015, for Phase 2 of the order. Therefore, along with the Phase 1 six-month status report, the OIP for Phase 2 of the Order pursuant to Section IV, Condition D.2, of Reference 1 is enclosed as Attachment 2.

Additionally, PNPS's responses to the Phase 1 Interim Staff Evaluation Open Items are contained in Attachment 3.

Entergy plans to permanently cease operation of PNPS no later than June 1, 2019. The Hardened Containment Vent System Phase 1 and Phase 2 strategies documented in this submittal are accurate descriptions of the current planned modifications and/or strategies to satisfy the requirements of NRC Order EA-1 3-1 09.

This letter contains no new regulatory commitments.

Should you have any questions concerning the content of this letter, please contact Mr. Everett (Chip) Perkins, Jr. at (508) 830-8323.

I declare under penalty of perjury that the foregoing is true and correct; executed on December 17, 2015.

Sincerely, JAD/rm b

PNPS Letter 2.15.082 Page 3 of 3 Attachments: 1] Pilgrim Nuclear Power Station's Third 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) 2] Pilgrim Nuclear Power Station's Phase 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-1 3-1 09) 3] Pilgrim Nuclear Power Station's Responses to Phase 1 Interim Staff Evaluation Open Items cc: Mr. Daniel H. Dorman Regional Administrator, Region I U.S. Nuclear Regulatory Commission 2100 Renaissance Boulevard, Suite 100 King of Prussia, PA 19406-1415 U. S. Nuclear Regulatory Commission Director, Office of Nuclear Reactor Regulation Washington, DC 20555-0001 Ms. Booma Venkataraman, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8C2A Washington, DC 20555 Mr. John Giarrusso Jr.

Planning, Nuclear and Preparedness Section Chief Mass. Emergency Management Agency 400 Worcester Road Framingham, MA 01702 NRC Resident Inspector Pilgrim Nuclear Power Station

ATTACHMENT 1 To PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Third 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)

(3 pages)

Attachment 1 PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Third Six-Month Status Report in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-13-109) 1 Introduction Pilgrim Nuclear Power Station (PNPS) developed an Overall Integrated Plan (OIP) (Reference 1 in Section 8), documenting the installation of a Hardened Containment Vent System (HCVS) that provides a reliable hardened venting capability for pre-core damage and under severe accident conditions, including those involving a breach of the reactor vessel by molten core debris, in response to Reference 2. This attachment provides an update of milestone accomplishments since submittal of the Phase 10CIP and the First and Second Six Month Status Report, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments The following milestone(s) have been completed since the development of the OIP (Reference 1),

and are current as of December 18, 2015.

• The Overall Integrated Plan was issued on June 30, 2014.

• The First Six Month Status Report was issued on December 16, 2014

• The Second Six Month Status Report was issued on June 30, 2015

• The Interim Staff Evaluation (ISE) was received on March 24, 2015 3 Milestone Schedule Status The following provides an update to Part 5 of the OIP. It provides the activity status of each item, and whether the expected completion date has changed. The dates are planning dates subject to change as design and implementation details are developed.

Milestone Target Activity Comments Completion Date Status Complete HCVS Gap Analysis June 2014 Complete Submit Overall Integrated Plan .June 2014 Complete Submit 6 Month Status Report December 2014 Complete Submit 6 Month Status Report June 2015 Complete December 2015 Complete Simultaneous Phase 20QIP with Submit 6 Month Status Report Design Engineering On-site/Complete July 2016 Started

Milestone Target Activity Comments Completion Date Status Submit 6 Month Status Report June 2016 Not Started Operations Procedure Changes Developed December 2016 Not Started Site Specific Maintenance Procedure Developed December 2016 Not Started Submit 6 Month Status Report December 2016 Not Started Training Complete December 2016 Not Started Implementation Outage March 2017 Not Started Procedure Changes Active March 2017 Not Started Walk Through Demonstration/Functional Test March 2017 Not Started Submit Completion Report June 2017 Not Started 4 Changes to Compliance Method There are no changes to the compliance method as documented in the Phase 10OIP (Reference 1).

5 Need for RelieflRelaxation and Basis for the RelieflRelaxation As noted in this submittal cover letter, Entergy plans to permanently cease operation of PNPS no later than June 1, 2019. The Hardened Containment Vent System Phase 1 and Phase 2 strategies documented in this submittal are accurate descriptions of the current planned modifications and/or.

strategies to satisfy the requirements of NRC Order EA-1 3-109.

6 Open Items from Overall Integrated Plan and Interim Staff Evaluation PNPS has received the Interim Staff Evaluation (ISE) with Open Items identified (Reference 7).

These open items have been addressed in an attachment to this status report submittal.

7 Interim Staff Evaluation Impacts There are no potential impacts to the Interim Staff Evaluation identified at this time.

8 References The following references support the updates to the Phase 0I aP described in this enclosure.

1. Pilgrim's 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), dated June 30, 2014.

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

3. NEI 13-02, "Industry Guidance for Compliance with NRC Order EA-1 3-1 09, To Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," Revision 0, dated November 2013.

4. NRC Interim Staff Guidance JLD-ISG-2013-02, "Compliance with 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 November 2013 (Accession No. ML13304B836).

5. NRC Endorsement of Industry "Hardened Containment Venting System (HCVS) Phase 1 Overall Integrated Plan Template (EA-1 3-1 09) Rev 0" (Accession No. ML14128A219).

6. Nuclear Regulatory Commission AUdits of Licensee Responses to Phase 1 of Order EA 109 to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions (Accession No. ML14126A545).

7. Nuclear Regulatory Commission Interim Staff Evaluation dated March 24, 2015, "Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Phase 1 of Order EA-1 3-1 09 (Severe Accident Capable Hardened Vents). (Accession No. ML15043A754) (PNPS Letter 1.15.016).

ATTACHMENT 2 To PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Phase 2 Overall Integrated Plan in Response to June 6, 2013 Commission Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions (Order Number EA-1 3-1 09)

• (50 pages)

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Table of Contents:

General Integrated Plan Elements and Assumptions Part 1:

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 3.1A Boundary Conditions for SAWA/SAWM Part 3.IB 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 .1.0: 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 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Introduction In 1989, the NRC issued Generic Letter 89-16, "Installation of a Hardened Wetwell Vent," to all licensees of 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 Torus 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.

On March 19, 2013, the Nuclear Regulatory Commission (NRC) Commissioners directed the staff per Staff Requirements Memorandum (SRM) for SECY 0 157 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-13-109, Issuance of Order to Modifying Licenses withi Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accidents, June 6, 2013. The Order (EA-13-109) 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 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 drywell 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 drywell 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-l13-109 through Interim Staff Guidance (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 Revision 0 and 1, Compliance with OrderEA-13-109, Severe Accident Reliable Hardened Containment Vents, with clarifications. Except in those cases in which a licensee proposes an acceptable alternative method for complying with Order EA-13-109, the NRC staff will use the methods described in the ISGs to evaluate licensee compliance as presented in submittals required in Order EA-13-109.

The Order also requires submittal of an overall integrated plan which will provide a description of how the requirements of the Order will be achieved. This document provides the Overall Integrated Plan (OIP) for complying with Order EA-13-109 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 EA 13-109.

Page 2 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 The submittals required are:

• OIP for Phase 1 of EA-13-109 was required to be submitted by Licensees to the NRC by June 30, 2014. The NRC requires periodic (6 month) updates for the 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-13-109 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 20GIP submittal by means of a combined Phase 1 and 20OP.

[] Thereafter, the 6 month updates will be for both the Phase 1 and Phase 2 actions until complete, consistent with the requirements of Order EA- 13-1 09.

Note: At the Licensee's option, the December 2015 six month update for Phase 1 is included with this Phase 20OIP submittal.

The Plant venting actions for the EA-13-109, Phase 1 severe accident capable venting scenario can be summarized by the following:

• The HCVS will be initiated via manual action from the either the Main Control Room (MCR) 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.

o 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 at least 7 days.

The Phase 2 actions can be summarized as follows:

• The PNIPS FLEX Severe Accident Strategy is based on the use of Severe Accident Water Addition (SAWA), Severe Accident Water Management (SAWM), and Severe Accident Wetwell Venting (SAWV) to achieve safe shutdown conditions in the best manner possible for the given Beyond-Design-Basis External Event (BDBEE). The "HCVS Phase 2" Strategy is a seamless transition of the FLEX SAWA / SAWM / SAWV Strategy, i.e., Phase 2 is simply an extension of the FLEX-Phase 1 Severe Accident Strategy that is implemented as early as possible to mitigate core damage as shown in the Attachment 2 Figures of the EA-1 3-109 Phase 1 Overall Integrated Plan (OIP) with the SAWMV injection rates controlled to utilize the available Torus water capacity as effectively as possible to continue with only Wetwell (Torus) venting f*or the event duration.

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

• Utilization of Severe Accident Water Management (SAWMV) to control injection and Torus level to ensure the HCVS (Phase 1) Wetwell vent (SAWV) will remain functional for the removal of decay heat from Containment.

Page 3 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 o Ensure that the decay heat can be removed from the Containment for at least 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 drywell 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.

oParameters measured include Containment pressure, Torus level, SAWA flowrate and the HCVS parameters listed above.

Page 4 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 1: General Integrated Plan Elements and Assumptions Extent to which the guidance, JLD-ISG-2013-02, JLD-ISG-2015-01 and NEI 13-02 (Revision 1),. ,:

are being followed. Identify any deviations.

Include a description of any alternativesto the guidance. A technicaljusti~fication and basisfor the alternative needs to be provided. This will likely require a pre-meeting with the NRC to review the alternative.

Ref: JLD-ISG-2013-02, JLD-ISG-2015-01 Compliance will be attained for PNPS 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 Hardened Containment Vent System (HCVS) will be comprised of installed and portable equipment and operating guidance:

• Severe Accident Wetwell Vent (SAWV) - Permanently installed vent from the Torus to the Main Plant Stack.

• Severe accident Water Addition (SAWA) - A combination of permanently installed and portable equipment to provide a means to add water to the 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 2Q2017.

• 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 2Q20 19.

If deviations are identified at a later date, then the deviations will be communicated in a future 6 month update following identification.

State Applicable Extreme External Hazard from NEI 12-06, Section 4.0-9.0 List resultantdetermination of screened in hazardsfrom the EA-12-049 Compliance.

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

• Seismic, Snow, Ice and Extreme Cold, High Wind, Extreme High Temperature The following extreme external hazards screen out for PNPS:

• External Flooding Key Site assumptions to implement NEi 13-02 HCVS, Phase 1 and 2 Actions.

Provide key assumptions associatedwith implementation of HCVS Phase 1 and Phase 2 Actions Ref: NET 13-02, Revision 1, Section 2 NET 12-06 Revision 0 Page 5 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 1: General Integrated Plan Elements and Assumptions Mark I/II Generic EA-13-109 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 RCIC or HPCI. (Reference NEI 12-06 3.2.1.3 item 9).

049-5. At Time =0 the event is initiated and all rods inser-t and no other event beyond a common site ELAP is occurring at any or all of the units. (NEI 12-06, section 3.2.1.3 item 9 and 3.2.1.4 item 1-4).

049-6. At Time = 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> an ELAP is declared and actions begin as defined in EA-12-049 compliance.

049-7. DC power and distribution can be credited for the duration determined per the EA-1 2-049 (FLEX) methodology for battery usage, with capacity greater than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. This assumption applies to the water addition capability under SAWA/SAWM. The power supply scheme for the HCVS shall be in accordance with EA-13-109 and the applicable guidance. (NEI 12-06, section 3.2.1.3 item 8).

049-8. Deployment resources are assumed to begin arriving at Time = 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and fully staffed by 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

049-9. All activities associated with plant specific EA-12-049 FLEX strategies that are not specific to implementation of the HCVS, including such items as debris removal, communication, notification, 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)(HCVS-FAQ-1 1).

Applicable EA- 13-109 generic 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. 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 SAWA/SAWM because SAWA equipment needs to be connected and placed in service within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 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 t~o prevent. (Reference NEI 13-02 section 2.3.1).

Page 6 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 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, valving-in nitrogen bottles) are acceptable to obtain HCVS venting dedicated functionality (Reference HCVS-FAQ-0 1).

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 <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> from the time of the loss of RPV injection and will require more than minimal operator action, but these actions are in areas that are accessible and well shielded from radiological effects.

109-07. IICVS 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 White Paper HCVS-WP-0 1).

This assumption does not apply to Phase 2 SAWA/SAWM 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 MAAIP Endorsement ML13190A201) Additional analysis using RELAP5/MOD 3, GOTHIC, PCFLUD, LOCADO SE 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 drywell temperature response to SAWA under severe accident conditions.

109-09. NRC Published Accident evaluations (e.g. SOARCA, SECY-12-0 157, and NUREG 1465) as related to Order EA-13-109 conditions are acceptable as references. (Reference NEI 13-02 section 8).

109-10. Permanent modifications installed or planned per EA- 12-049 are assumed implemented and may be credited for use in EA- 13-109 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/SAMG procedure change process. This assumption does not apply to Phase 2 SAWM because SAWM is not part of Revision 3. (Reference to 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 3-109 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 10OCFR50 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-0 1 and HCVS-FAQ-09).

109-13. The Suppression Pool / Wetwell of a BWR Mark I 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 NEI 13-02 Rev 1, §I.1.3).

109-15. The Severe Accident impacts are assumed on one unit only due to the site compliance with NRC Order EA-1 2-049. However, each BWR Mk I and II under the assumptions of NRC Order EA-1 3-109 ensure the capability to protect Containment exists for each unit (HCVS-FAQ-1). This is further addressed in HCVS-FAQ-l10.

Plant Specific HCVS Related Assumptions/Characteristics:

None.

Page 7 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Providea s'equence of events ~and identify any time or environmental constraint, required for success includin g the blasis for the constrai~nt. ,, , ' / ,i, ,: i" , * - ;  !

HCVS Actions that have a time constraint to be successful should be identified with a technical basis and ajustification 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 ofHigh 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 attached sequence of events timeline (Attachment 2A)

Ref: EA-13-109 Section 1.1.1, 1.1.2, 1.1.3 I NEI 13-02 Section 4.2.5, 4.2.6. 6.1.1 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

• Provide a sequence.e of events sand identify an y;tire or enwironmental constraint ,requiredfor success icluding the,*

Refer to the EA-1 3-109 Phase 1 Overall Integrated Plan.

Provide :Details onthe Vent ,characteristics:s ,*:  : ' *: **;!*  !

Provide Details on the Vent characteristics Vent Size and Basis (EA-13-109 Section 1.2.1 /NEI13-02 Section 4.1.1)

UWhat is the plants licensedpower? Discuss any plansfor possible increases in licensedpower (e.g. MUR, EPU).

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

Vent Capacity (EA-13-109 Section 1.2.1/INEI113-02 Section 4.1.1)

Indicate any exceptions to the 100 decay heat removal criteria, including reasonsfor the exception. Provide the heat capacity of the suppressionpool in terms of time versus pressurizationcapacity, assuming suppressionpool is the injection source.

Vent Path and Dischargie (EA 109 Section 1.1.4, 1.2,2/NEI13-02 Section 4.1.3, 4.1.5 and Appendix FIG)

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

Power and Pneumatic Supply Sources (EA-13-109 Section 1.2.5 & 1.2.6/INEI 13-02 Section 4.2.3, 2.5, 4.2.2, 4.2.6, 6.1)

Provide a discussion of electricalpower requirements, including a description of dedicated24 hourpower supply from permanently installed sources. Include a similardiscussion as abovefor the valve motive force requirements. Indicate the area in the plantfrom where the installed/dedicatedpower and pneumatic supply sources are coming.

Page 8 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Indicate the areas where portable equipment will be staged after the 24 hourperiod, 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 Control Panels (EA 109 Section 1.1.1. 1.1.2, 1.1.3, 1.1.4, 1.2.4, 1.2.5/ NEIJ13-02 Section 4.1.3, 4.2.2, 4.2.3, 4.2.5, 4.2.6, 6.1.1 and Appendix F/G)

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

Hvdrogien (EA-13-109 Section 1.2.10, 1.2.11, 1.2.12 /NEI 13-02 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 offlammable gases, clearly demarcating the 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 /NEI 13-02 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 interfacing valves or Appendix J type testingfeatures?

Prevention of InadvertentActuation (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.

Monitoringof HCVS (Order Elements 1.1.4, 1.2.8, 1.2.9/NE113-02 4.1.3, 4.2.2, 4.2.4, and Appendix FIG)

Provides a description of instruments used to monitor HCVS operationand effluent. Powerfor an instrument will require the intrinsically safe equipment installed as part of the power sourcing.

Component reliable and ruggj~ed performance (EA-13-109 Section 2.2 /NEI 13-02 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 instrumentation that are not requiredto be seismically designed by the design basis of the plant should be designedfor reliable and ruggedperformance that is capable of ensuringHC VS functionalityfollowing a seismic event. (Reference ISG-JLD-201201 and ISG-JLD-2012-03for 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 NE1 12-0 6 as endorsed by JLD-ISG-12-Olfor OrderEA-12-049.

Use of instruments and supportingcomponents with known operatingprinciples that are supplied by manufacturers with commercial quality assuranceprograms, such as IS09001. The procurement specifications shall include the seismic requirements and/or instrument design requirements, and speciify the need for commercial design standards and testing under seismic loadings consistent with design basis values at the instrument locations.

Demonstration of the seismic reliabilityof the instrumentation through 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 IEEE Standard 344-2004, "IEEERecommended Practice Page 9 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent for Seismic Qualification of Class JE Equipmentfor NuclearPower GeneratingStations, " or a substantiallysimilar industrialstandardcould be used.

Demonstration that 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 that performedfor the plant licensing basis.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Page 10 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent

~Part 2 Boundary Conditions for WW 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 descri~ption of the venting actionsforfirst 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment including station modifications that areproposed.

Ref: EA-13-109 Section 1.2.6 / NEI 13-02 Section 2.5, 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

• * .... Greater Than 24 Hour CoigDetail , °°'*

Provide a general descri~ption of the venting actionsfor greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> usingportable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 / NEI 13-02 Section 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

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

Provide a brief description of Procedures I Guidelines:

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

NET 13-02 §6.1.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Identify modifications."

List modifications and describe how they support the HCVS Actions.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Key Venting Parameters:

List instrumentation creditedfor 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).

Page 11 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary conditions for Wetwell Vent

:" Part 2 Boundary"Conditions for WW Vent:....BEE Venting Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Notes: For the BDBEE Case #1 where the FLEX Strategy is successfully implemented, Wetwell venting is initiated at 16 Hours after Shutdown when or before the Suppression Pool exceeds 281 0 F.

Part 2: Boundary Conditions for Wetwell Vent

,,,,* :Part 2, Boundary Conditions for WW Vent: Severe Accident Venting,,,:: *;

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

Ref: EA-13-109 Section 1.2.10 / NET 13-02 Section 2.3 o First 24Hur Coping Detail

• Provide a general description of the venting actionsfor first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment includingstation modifications that areproposed.

Ref: EA-13-109 Section 1.2.6 / NET 13-02 Section 2.5, 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

• Details:

Provide a general descriiption of the venting actionsfor greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> usingportable and installed equipment including station modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8 1 NET 13-02 Section 4.2.2 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

" First 24 Hour Coping Detail Provide a brief description of Procedures / Guidelines:

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

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Page 12 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Part 2 Bondary Conditions for WW Vent: Severe Accident Venting Identify modifications."

List modifications and describe how they support the HCVS Actions.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

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).

Refer to the EA- 13-109 Phase 1 Overall Integrated Plan.

Notes: For the postulated Short-Term Severe Accident Case #2B (refer to EA-13-109 Phase 10OP), the Containment Maximum Allowable Working Pressure (MAWP) 62 PSIG Limits are not exceeded when the FLEX injection is initiated by 8 Hours, thereby preventing Containment failure and cooling the overheated core debris, with Wetwell Venting shortly thereafter (at 10 Hours) when Torus Bottom Pressure is at or above the PCPL. It should be considered that, as soon as H2 gas evolution begins and the Torus Bottom Pressure approaches the PCPL value of 60 psig, that Wetwell Venting will be initiated and will mitigate the peak pressure that occurs with continued H2 generation.

Page 13 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent S Part 2 Boundary Conditions for WW Vent: HCVS Su~pport 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. Identify 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 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

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 / NEI 13-02 Section 2.5, 4.2.2, 4.2.4, 6.1.2 Refer to the BA-i13-109 Phase 1 Overall Integrated Plan.

D...etails ..

Provide a brief description of Procedures IGuidelines:

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

Refer to the EA* 13-109 Phase 1 Overall Integrated Plan.

Identify modifications:

List modifications and describe how they support the HCVS Actions.

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Page 14 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent

,Part 2 Boundary Conditions fo)r WW Vent: HCVS Support Equipment Functions 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).

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Notes: The HCVS Torus Vent at PNPS includes an 8" Air-Operated Butterfly Valve AO-5025 capable of venting the Wetwell (Torus) airspace through an 8" branch line between the two Primary Containment Isolation Valves (PCTVs)

AO-5042A & B from 20" Torus Penetration X-227. The HCVS Torus Vent flow path via AO-5042B & AO-5 025 cornects to the 20" discharge line downstream of the Standby Gas Treatment System (SGTS) filter trains. The vent flow path is isolated from the SGTS by Air-Operated Discharge Valves AO-N-108 & 112 on the SGTS outlet where the vent 8" piping connects to the 20" discharge piping to the plant's Main Stack that includes a buried piping run from the plant out to the Main Stack.

Page 15 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 2: Boundary Conditions for Wetwell Vent Part 2 Boundary Conditions for WW Vent: HCVS Venting Portable. Equipment, Deployment*

Provide a general descrijption of the venting actions usingportable equipment including modifications that areproposed to maintain and/or support safety functions.

Ref: EA-13-109 Section 3.1 / NET 13-02 Section 6.1.2, D.1.3.1 Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Provide a brief description of Procedures / Guidelines:

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

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

THCVS Actions Modifications Protection of connections Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Notes: A condensate drain trap, manual isolation valves, and flex hose quick-connect fittings have been installed downstream of SGTS Piping Drain Valve 44-HO-i 14 as part of the FLEX modifications. Prior to venting, a pre-staged flexible hose is connected to this fitting and routed to the Torus Room to drain condensate from the vent pipeline.

Page 16 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3: Boundary Conditions for EA-1 3-1 09, Option B.2 General:...

Licensees that use Option B.] of EA-13-109 (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-13-] 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 Part2 apply to all of thefollowing:

This Partis divided into the following sections."

3.1.' Severe Accident Water Addition (SA WA) 3.1.A: Severe Accident Water Management (SA WMV) 3.1.B: Severe Accident DW Vent (545 degF)

Provide a se'quence of events and identify any time constraint requi~red for success including the basis

'for the time* constraint. " ': " * '  :

SA WA and SA WM or SAD V Actions 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 HC VS part of this template need not be repeated here.

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

• Electricalgenerators 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 SA WA are those actions needed to transport, connect and startportable 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 instrumentation should 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 MCR using control switches. In addition, HCVS operation may occur at the ROS.

Timelines (see attachments to the Phase 1 OIP) were developed to identify required operator response times and actions.

Page 17 of50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA Tabl~e 3.1 - SAWA Manual ACtions ...

Primary Action Primary Location / Component Notes

1. Establish HCVS capability in U MCR or ROS U Applicable to SAWA/SAWM accordance with Part 2 of the strategy Phase 1 OWP for this Order.

2. Connect FLEX Pump discharge to U HPCI/RCIC connection is the U No hose connections within the FLEX injection piping. primary connection point via Reactor Building are required for external connection to the RPV make-up.

CST. Same connection as FLEX, external to Reactor Building. RHR is the backup and is in the Auxiliary Bay Building.

3. Connect FLEX Pump to water U] Primary connection is the U The location of this source, as well source. normal UIHS intake water as the location of the FLEX Pump, source. is not challenged by severe accident radiological conditions.

4. Power SAWA/HCVS components U One FLEX Portable 480 VAC U No changes required to the with EA-12-049 (FLEX) 3-PH 150 kW Diesel original EA-12-049 strategy.

generator. Generator (DG) will normally be pre-staged in the Turbine Building Truck Lock, which is adjacent to the AC Switchgear and DC System Battery Rooms. This DG is thereby capable of early deployment (within 4 Hours) during any Station Black-Out (SBO) and is capable of maintaining both 125 VDC Battery Divisions, and the 250 VDC Battery, charged and operating indefinitely.

There are additional 86 kW DGs in the dual FLEX Storage sites that are deployable within 6 Hours to perform the same functions.

Page 18 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA

5. Inject to RPV using FLEX Pump U SAWA flow control will be U] Initial SAWA flow rate is (diesel). provided by variable speed 300 gpm per Calculation M 1380 pump controller and by (see Phase 10GIP).

throttling valves at a Strainer Cart; both of which are outside Rx Bldg.

6. Monitor SAWA indications. U] Total flow and SFP flow U] Strainer Cart is outside reactor meters are included in the building and is not challenged by Strainer Cart. severe accident radiological K Containment parameters conditions.

monitored at MCR.

7. Use SAWM to maintain A MCR for indication

• Monitor DW pressure and availability of the Torus Vent U FLEX Pump location for flow Wetwell level in MCR (Part 3.1.A). control.

• Control SAWA flow with variable speed pump controller and by throttling valves at the Strainer Cart as-needed.

Discussion of timeline SAWA identified items HCVS operations are discussed under Phase 1 of EA-13-109 (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-12-049 conditions after RPV level lowers to 2/3 core height are consistent with the radiological conditions assuming permanent Containment shielding remains intact. All other actions required are assumed to be in-line with the FLEX timeline submitted in accordance with the EA-12-049 requirements.

• 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 operating requirementsfor 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 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, as is required to be considered by EA-l13-109 regardless of the adequacy of the FLEX Strategy to prevent such core damage. The SAWA Strategy includes both portable and installed equipment that is also used for the FLEX Strategy, i.e., SAWA utilizes the same injection equipment and methods as FLEX and may be used to recover from any failure to initially implement the FLEX Strategy, or utilize alternative but equivalent equipment if needed.

Page 19 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA The motive force equipment needed to support the SAWA strategy shall be available prior to T = 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 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. Backflow from the reactor/Containment through the FLEX Pumps is prevented by check valves in the RCIC/HPCI system.

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

T <1 hr:

• No evaluation required for actions inside the Reactor Building for SAWA. Expected actions are:

o Begin preparations to connect SAWA hose to the primary injection point, CST, outside the Reactor Building. Any actions performed inside the Reactor Building will be for evaluation of conditions (depending on the BDB Event) or preparatory activities in well shielded normally accessible areas of Secondary Containment that will be at effectively normal radiation dose rates. There will be no unusual restrictions imposed on Reactor Building access by the FLEX Strategy, any restrictions will be based on actual dose rates.

T= 1 - 8hrs:

• Evaluation of core gap and early in-vessel release impact to Reactor Building access for SAWA will be performed as-needed. It is assumed that Reactor Building access is limited due to the source term at this time unless otherwise noted. The FLEX, HCVS, and Severe Accident strategies anticipate or plan activities only in readily accessible areas of Secondary Containment. These areas are well shielded and contain the alternate locations for instrument indications and backup Nitrogen (N2) supplies for HCVS and Safety-Relief Valve (SRV) operation. There are no required activities in the Torus Compartment, RHR Quad Rooms, TIP Room, or other high radiation dose areas. Areas that may have elevated dose rates following core damage or RPV breach are only considered accessible for potential activities early in the ELAP, when dose rates are still in the normal range. This includes localized areas that have line-of-sight exposure to HCVS vent piping. Expected actions are:

o Same as Table 2-1 "HCVS Operator Manual Actions" in Phase 10OP.

• Connect FLEX Pump to water supply at normal UHS intake water source (Step 3 of Table 3.1).

• Establish electrical power to HCVS and SAWA using EA-12-049 generator (Step 4 of Table 3.1).

• Establish initial flow of 300 gpm to the RPV using SAWA systems (Step 5 of Table 3.1).

T _<8 -24 hrs:

• Continue injection for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after SAWA injection begins at initial SAWA rate.

T >24 hrs:

• Proceed at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to MDRIR-based SAWM injection rates - SAWM actions (Part 3.1 .A)

(Step 7 of Table 3.1 above).

Page 20 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA Provide a general description of the SA WA actionsfor greaterthan 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> usingportable and installed equi~pment including station mocifications that are proposed.

Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3/ NET 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).

Details of Design Characteristics/Performance Specifications SA WA shall be capable ofproviding an RPV injection rate of 300 gpm within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of a loss of all RaPV injection following an ELAP/Severe Accident. SA WA shall meet the design characteristicsof the HCVS.

Ref: EA-13-109 Attachment 2, Section B.2.1, B.2.2, B.2.3/ NET 13-02 Section 1.1.4 Equipment Locations/Controls/Instrumentation PNPS has performed a site specific evaluation to justify the use of a lower site unique initial SAWA flow rate.

Consequently, PNPS will assume an initial flow rate of 300 gpm. This initial flow rate will be established within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the loss of all RPV injection following an ELAP/Severe Accident and will be maintained for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> before reduction to the flow rate that allows continued flooding of the RPV & DW Core Debris at the Minimum Debris Retention Injection Rate (MDRIR) based flow rate with only Wetwell venting.

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 ERO dose and plant safety guidelines for temperature and humidity.

The flow path will be from the FLEX Pump suction at the UH1S intake, through the FLEX Pumps and associated hoses and Strainer Cart to the connection point at the CST Vault Backflow from the Reactor / Containment through the FLEX Pumps is prevented by check valves in the RCIC / HIPCI Systems.

DW pressure and Wetwell level will be monitored and flow rate will be adjusted by adjusting the variable speed engine-driven FLEX Pump and throttling the manual valves located on the SAWA Strainer Cart. Communication will be established between the MCR and the SAWA flow control location.

The FLEX Pump suction source is a significant distance from the discharge of the HCVS pipe (Main Plant Stack) with substantial structural shielding and distance between the HCVS pipe and the pump deployment location. FLEX Pump and diesel driven generator refueling will also be accomplished using portable transfer pumps and truck-mounted fuel dispensing tanks.

Initial evaluations for projected SA conditions (radiation / temperature) 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).

Page 21 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan December 2015 Part 3.1: Boundary Conditions for SAWA DC-powered electrical equipment and instrumentation will be powered from the battery chargers that are repowered from the EA- 12-049 generator(s) to maintain the battery capacities during the Sustained Operating period and 120 VAC powered instrumentation, including the Post-Accident Monitoring (PAM) System, will be repowered directly from the same generators.

Parameter Instrument Location Power Source / Notes Wide Range Primary Containment Pressure MCR Panels Repower via EA-12-049 (0 to 225 psig) 120 VAC PI-1001-600A/B C170/C171 FLEX Diesel Generator Panel Y3/Y4 Torus Water Level MCR Panels Repower via EA-12-049 (0 to 300 inches) LI-1001-604A/BC70C1FLXDelGnrao 120 VAC Y3/Y4C1017FEXDelGnrao FLEX Pump Flow Battery Operated (one AW FlwIndicator / Totalizer FLXSrie at year replaceable Li-Ion)

The instrumentation and equipment being used for SAWA and supporting equipment has been evaluated to perform for the Sustained Operating period under the expected radiological and temperature conditions.

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. The connection for the FLEX Pump injection is protected by the CST Vault Missile Protection Enclosure. Portable equipment used for SAWA implementation will meet 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 / NEI 13-02 Section 1.3, 6.1.2

• Connect FLEX Pump discharge to CST that connects with RCIC / HIPCI.

• Power SAWA / HCVS components with EA-12-049 (FLEX) generator using FLEX procedures.

• Start FLEX Pump to establish SAWA flow.

• Adjust flow rate using skid mounted flow indicator and variable speed FLEX Pump Page 22 of 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1: Boundary Conditions for SAWA Identify modifications:

List modifications 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 None.

Component Qualifications:

State the qualification usedfor equipment supportingSA WA Ref: EA-13-109 Attachment 2, Section B.2.2, B .2.3 I NEI 13-02 Section 1.1.6 Permanently installed plant equipment shall meet the same qualifications as described in Part 2 of the Phase 10OIP.

Temporary/Portable equipment shall be qualified and stored to the same requirements as FLEX equipment as specified in NEI 12-06 Rev 0.

Notes: The postulated Short-Term STSBO Severe Accident scenario Case #2B (refer to EA-13-109 Phase 10OIP),

includes the immediate or early failure of the steam-driven RCIC & HPCI Systems and results in the most rapid core overheating, damage, and RPV breach, which occurs at 8.2 Hours after Shutdown. This allows sufficient time for the FLEX Low Pressure Injection Source to be deployed and begin RPV injection at 300 GPM for RPV and core debris cooling while venting is initiated at the PCPL with the Wetwell at or above 250°F due to the combination of steam and Hydrogen (H2) gas pressure from the core overheating. The 300 GPM injection is continued until the Wetwell is cooled below 250°F, at which time the FLEX injection rate is reduced from 300 GPM to the SAWMV injection rates that conservatively bounds the EOP Minimum Debris Retention Injection Rate (MIDRIR) which maintains the core debris completely cooled while preserving the ability to continue Wetwell Venting for Containment Heat Removal and purging of the steam-diluted Hydrogen gas.

Page 23 of 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.,tA: Boundary Conditions for SAWA/SAWM Time periods for maintaining SAWM actions such that the WW vent remains available SA WM iActions supportingSA conditions that have a time constraint to be successful should be identified with a technical basis and a justificationprovided that the time can reasonably be met (for example, a walkthrough of deployment). Actions already identified under the HC VS part of this template need not be repeated here.

There are three time periodsfor the maintaining SA WM actions such that the Wetwell 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 modifications or procedures is necessary with respect to how alternate Containment heat removal will be provided.

• ] SAWM can be maintainedfor at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, but less than 7 days before DWpressure reaches PCPL or design pressure, whichever is lower.

o Under this approach, a functional 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 and pressure 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 <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before DW pressure reaches PCPL or design pressure whichever is lower.

o Under this approach, a functional 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, physicalplant modifications and detailedprocedures are required to be implemented to insure achieving alternateContainment heat 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 drywell vent to maintain pressure below PCPL.

Basis for SAWM time frame .. . . ... *.. ,,...  ; ... ..

Option 1 - SAWM can be maintained greater than or equal to 7 days:

PNPS has performed a site specific evaluation to determine the initial SAWA flow rate. PNIPS will establish an initial flow rate of 300 gpm.

This initial flow rate will be established within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the loss of all RPV injection following an ELAP/Severe Accident and will be maintained for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> before reduction to the flow rate that allows continued flooding of the RPV & DW Core Debris at the Minimum Debris Retention Injection Rate (MDRIR) based flow rates with only Wetwell Venting for the duration of the event.

Instrumentation relied upon for SAWM operations is Drywell Pressure, Torus level, and SAWA flow. Except for SAWA flow, SAWM instruments are initially powered by station batteries and then by the FLEX (EA- 12-049) generator which is placed in-service prior to core breach. 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 Page 24 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1 oA: Boundary Conditions for SAWAISAWM 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. (C.7.l1.4.2, C.8.3.l)

Torus level indication is maintained throughout the Sustained Operation period, so the HCVS remains in-service. The time to reach the level at which the Torus Vent must be secured is >7days using SAWM flowrates (C.6.3, C.7. 1.4.3).

Table 3.1 .B -' SAWM Manual Actions Primary Action Primary Location / Notes Component

1. Lower SAWA injection o Containment parameters U Control to maintain Containment and rate to control Torus monitored in the MCR Torus parameters to ensure Torus vent Level and decay heat

• Flow control at FLEX remains functional.

removal Pump and Strainer Cart U MDRIR-Based SAWMV flow rate minimum capability is maintained for greater than 7 days

• SAWA/SAWM flow rates will be controlled using variable speed pump controller at the Pump Skid and by throttling valves at the Strainer Cart.

2. Control to SAWM

• Flow control at FLEX U SAWM flow rates will be monitored using flowrate for Containment Pump and Strainer Cart the following instrumentation control /decay heat o SAWA Flow removal o Torus Level a Containment Pressure

• SAWM flow rates will be controlled using a variable speed pump controller at the Pump Skid and by throttling valves at the Strainer Cart.

3. Establish alternate source a Yard U >7 days of decay heat removal

4. Secure SAWA / SAWM

• FLEX Pump U When reliable alternate Containment decay

• IFLEX Strainer Cart heat removal is established.

SAWM Time Sensitive Actions Time Sensitive SAWMI Actions:

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

Page 25 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1.A: Boundary Conditions for SAWA/SAWM 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 / NEI 13-02 Appendix C It is anticipated that SAWMV 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using installed equipment including station mnodifications that are proposed.

Given the initial conditionsfor EA-13-109:~

[] BDBEE occurs with ELAP

• ] Failure of all injection systems, includingsteam-powered injection systems Ref: EA-13-109 Section 1.2.6, Attachment 2, Section B.2.2, B.2.3 1 NET 13-02 2.5, 4.2.2, Appendix C, Section C.7 SAWA will be established as described 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 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, the flow will be reduced while monitoring DW pressure and Torus level. SAWM flowrate can be lowered to maintain Containment parameters and preserve the Tours 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 WA! actionsfor greaterthan 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> using portable and installed equipment includingstation modifications that are proposed.

Ref: EA-13-109 Section 1.2.4, 1.2.8, Attachment 2, Section B.2.2, B.2.3 / NET 13-02 Section 4.2.2, Appendix C, Section C.7 SAWMV can be maintained >7 days:

The SAWMV flow strategy will be the same as the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> until 'alternate reliable Containment heat removal and pressure control' is reestablished. SAWM flow strategy uses the SAWA flow path. No additional modifications are being made for SAWM.

Page 26 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1.A: Boundary Conditions for SAWAISAWM

" ' ~ ~~~~Details: ' '.... . .... .

Details of Design Characteristics/Performance Specifications Ref: EA-13-109 Attachment 2, Section B.2.2, B.2.3 / NEI 13-02 Section Appendix C SAWM shall be capable of monitoring the Containment parameters (DW pressure and Torus 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 / NET 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 at the SAWA Strainer Cart by a portable flow instrument qualified to operate under the expected environmental conditions. The SAWA flow instrument is battery powered and can operate for one-year on two replaceable Li-Ion batteries. Communications will be established between the SAWM control location and the MCR.

SAWM injection flow rates will be controlled using the variable engine speed pump controller and by throttling valves at the Strainer Cart.

Torus level and DW pressure are read in the Main Control Room using indicators powered by the FLEX DG installed under EA-12-049. These indications are used to control SAWM flowrate to the RPV.

Key Parameters:

List instrumentation creditedfor the SA WivlActions.

Parameters used for SAWMV are:

[] DW Pressure

• ] Torus Level

[] SAWM Flowrate The Drywell Pressure and Torus Level instruments are qualified to RG 1.97 and are the same as listed in Part 2 of the Phase 10ITP. The SAWM flow instrumentation is portable, included with the FLEX Strainer Cart, and was selected for the expecte~d environmental conditions.

Notes: The SAWA / SAWM Strategy is simplified to the point that it could be successfully implemented using only the SAWM Flowmeters & Totalizers on the FLEX Strainer Cart for at least the initial 7 days.

Page 27 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 3.1°~B: Boundary Conditions for SAWA/SADV

"* '*....  : .. . .Applicability of' WW Desi'gn Consideration s ".; * ". .

This section is not applicable to PNPS.

Ta~ble 3.1.C -: SADV'ManUal Actions * "" .... :; ', °* "

Timneline for SADV SeveeAccident Venting ' ' '

"**, First-24 :Hour Coping Detail ... ... " .. ... t . .. * :

Greaiter Than 2 Hour Copin Detai

".. .De.. tails:tal °"  : " " " ... :"

Page 28 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance Idniyho~h rorm aiccnrlswl em et... ...

Provide a description of the programmatic controls equipmentprotection, storage and deployment and equipment quality addressing the 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-l13-109 and the hazards applicable to the site per Part 1 of this OIP.

o Routes for transporting portable equipment from storage location(s) to deployment areas have been developed.

The identified paths and deployment areas will be analyzed for potential radiation effects to ensure they remain fully accessible during Severe Accidents.

Procedures:

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

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

o appropriate conditions and criteria for use of the HCVS o when and how to place the HCVS in operation,

§ the location of system components,

• instrumentation available,

" normal and backup power supplies,

• directions for sustained operation, including the storage location of portable equipment,

• training on operating the portable equipment, and o testing of portable equipment.

PNPS 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 HCVS/SAWA functionality are applicable in 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:

Page 29 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance o 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 / NET 13-02 Section 6.1.3 Personnel expected to perform direct execution of the H-CVS/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.

Iidentf how the drills anid exercise parameters will be met.:  : * *<*," **.,..i..

Alignment with NEJ113-06 and 14-01 as codified in NTTF Recommendation 8 and 9 rulemaking The Licensee should demonstrate use of the HGCVS/SAWVA/SA WAM system in drills, tabletops, or exercises as follows:

Hardened Containment vent operation on normal power sources (no ELAP).

o During FLEX demonstrations (as required by EA-12-O49. Hardened Containmentvent operation on backup power andfrom primary or alternate location during conditions of ELAP/loss of UHS with no core damage.

System use isfor Containment heat removal AND 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 Containmentheat removal AND Containmentpressure control with potentialfor combustible gases (Demonstrationmay be in conjunction with SAG change).

• Operationfor sustainedperiod with SA WA and SA WM to 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.

Page 30 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance Describe maintenance plan:

Describe the elements of the maintenanceplan

" The maintenanceprogram should ensure that the HCVS/SA WA/SA WM equipment reliability is being achieved in a manner similar to that requiredfor FLEX equipment. Standard industry templates (e.g., EPRI) and associated bases may be developed to define specific maintenance and testing.

o Periodic testing andfrequency should be determined based on equipment type, expected use and manufacturer'srecommendations (furtherdetails are provided in Part 6 of this document).

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

o Preventive maintenance should be determined based on equipment type and expected use. The basis should be documented and deviationsfrom vendor reconumendationsand applicable standardsshould be justifled.

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

• HCVS/SA WA permanent installed equipment should be maintained in a manner that is consistent with assuring that it performs its function when required.

o HCVS/SA WA permanently installed equipment should be subject to maintenance and testing guidance provided to verify properfunction.

• HCVS/SA WA non-installedequipment should be stored and maintainedin a manner that is consistent with assuring that it does not degrade over longperiods ofstorage and that it is accessiblefor periodic maintenance and testing.

Ref: EA-13-109 Section 1.2.13 / NEI 13-02 Section 5.4, 6.2 PNPS will utilize the standard EPRI industry PM process (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.

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

Page 31 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015

-Part 4: Programmatic Controls, Training, Drills and Maintenance Table 4-1: Testing and Inspection Requirements Description Frequency Cycle the HCVS and installed SAWA valves' 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.

Perform visual inspections and a walk down of HCVS Once per every other4 operating cycle.

and installed SAWA components.

Functionally test the HCVS radiation monitor. 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 Once per every other operating cycle.

an 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.

lNot 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.

3Not 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.

Page 32 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 4: Programmatic Controls, Training, Drills and Maintenance SInterfacing 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 functional testing or system operation that reposition the valve(s) to the HCVS required position will meet this requirement without the need for additional testing.

Notes:

The PCIVs are required for Containment integrity during Modes 1-3 and thus are excluded from EA-1 3-109 testing requirements. These PCIVs are tested per the PNPS design basis requirements to ensure valve operability and leakage tightness.

Page 33 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 5: Milestone Schedule ProVide a milestone schedule ....  :

Provide a milestone schedule. This schedule should include:

o Modifications timeline o 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 order are 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:

Refer to the EA-13-109 Phase 1 Overall Integrated Plan.

Phase 2 M ilestone 'Schedule:.. . . . .. ..  ;* *,,...., , ......

Phase 2 Milestone Schedule Milestone Target Completion Activity Comments Date Status Submit Overall integrated Implementation Plan Dec 2015 Complete Separate submittal from Phase 1 update Submit 6 Month Status Report June 2016 Submit 6 Month Status Report Dec 2016 Submit 6 Month Status Report June 2017 Submit 6 Month Status Report Dec 2017 Design Engineering On-site/Complete Jan 2018 Not Started Submit 6 Month Status Report Jun 2018 Page 34 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Part 5: Milestone Schedule Submit 6 Month Status Report Dec 2018 Operations Procedure Changes Developed Dec 2018 Not Started Site Specific Maintenance Procedure Developed Dec 2018 Not Started Training Complete Dec 2018 Not Started Implementation Outage Feb 2019 Not Started Walk Through Demonstration/Functional Test Feb 2019 Not Started Procedure Changes Active Feb 2019 Not Started Submit Completion Report April 2019 Not Started Page 35 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 1: HCVSISAWA Portable Equipment Maintenance / PM requirements List portable equipment The portable equipment listed below supports SAWA/SAWM (Phase 2).

For a list of Phase 1 HCVS Equipment, refer to the Phase 1 Overall integrated Plan and associated 6 month updates FLEX DG (including cable, connectors, etc.) X X 150 & 86 kW Per Response to EA-12=049 DGs FLEX Pump (including dual strainer, X X 300 gpm for Per Response to EA-1 3-1 09 flowmeter, flexible hose, fittings, etc.) first 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> and MDRIR-Based Flowrates for at least the first 7 days Page 36 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2A: Sequence of Events Timeline - HCVS Refer to the EA-13-109 Phase 1 Overall Integrated Plan (page 40 of 58).

Page 37 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2.1 .A: Sequence of Events Timeline - SAWA I SAWM Refer to the EA-13-109 Phase 1 Overall Integrated Plan (Case 2A and 2B Graphs; page 41 and 42 of 58).

Page 38 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 .1 .B: Sequence of Events Timeline - SADV This is not applicable to PNPS.

Page 39 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2.10: SAWA / SAWM Plant-Specific Datum LOWER DRYWELL INSIDE SPHERICAL RADIUS 32 FT

.y 20-INCH DIAMETER HCVS VENT PIPING VERTICAL RISE TO EL 23 FT TIP ROOM REDUCE TO 8-INCH DIAMETER @ EL 28.6 FT LOWER DRYWELL EQUATOR @ EL 29.25 FT INLET TO PCIV &HCVS VALVE STATIONS DW VENT JET DEFLECTOR (81 6 FT 9-INCH DIAMETER DRYWELL VENT LINES TOP OF TORUS @EL 14.50 FT DW VENT C.L

@ EL 1325 FT MAXWATER LEVEL TO VENT 283 INCH @ EL 10.00 FT CL. OF VACUUM BREAKERS @ EL3.58 FT C.L. OF TORUS @ EL (-)0.25 FT NORMAL WATER LEVEL 130 INCH @ EL (-(2.75 FT TORUS WATER VOLUMES:

MAXWATER LEVEL TOVENT

- 1.500,000 GAL CL. OF VACUUM BREAKERS - 1,095.000 GAL iNORMAL WATER LEVEL - 650,000 GAL

• FT MAXNET WATER UP TO VENT - 850.000 GAL WIDE RANGE TORUS LEVEL 0 TO 300 IC

REFERENCES:

IOF TORUS @ EL (-(1500 FT CALCULATION M1380 DRAWINGS:

M23 M8649SH1 NOTE: CALCULATION M1380 CASE 2B SHORT-TERM SBO WITH NO RPV INJECTION FOR 8 HOURS IS THE BOUNDING SA. ANALYSIS.

FLEX SAWA INJECTION @ 300 GPM FROM 8 TO 24 HOURS FOLLOWED BY MDRIR-BASED INJECTION & WETWELL VENTING @ 10 HOURS. C1A1-8 C1A5-I1 C1A50-5 NET TORUS WATER ADDITION AFTER 30 DAYS IS LESS THAN 850,000 GAL WITH WETWELL VENTING ABOVE 220 OEGF. C1A51-7 C1A57-6 C 153 Page 40 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 2.1.D: SAWM SAMG Approved Lan~qua~qe The following general cautions, priorities and methods will be evaluated for plant specific applicabilityand incorporatedas appropriateinto the plant specific SAMGs using administrativeprocedures for EPG/SAG change contfrol process and implementation. SAMGs are symptom based guidelines and therefore address a wide variety of possible plant conditions and capabilitieswhile these changes are intended to accommodate those specific conditions assumed in OrderEA-13-109. The changes will lie 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 Language 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 Torus 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 1/1l suppression chamber vent paths, thereby retaining the benefits of Torus scrubbing and minimizing the likelihood of radioactivity and hydrogen release into the Secondary Containment (SAWM).

Page 41 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Methods:

Identify systems and capabilities to add water to the RPV or drywell, 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.

Page 42 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 3: Conceptual Sketches Refer to the EA-1 3-1 09 Phase I Overall Integrated Plan for the following sketches:

Electrical HCVS Electrical Layout Drawing Flow and Control Diagrams P&ID Layout of HCVS Plant Layout HCVS Local Panel HCVS Local Panel (Detail A)

Condensate Drain Hose Connection Standby Gas Treatment System Isolation Additional Phase 2 Sketches:

Sketch 1: FLEX / SAWA Equipment Location Sketch 2: FLEX I SAWA Power Distribution Page 43 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 FLOATING STRAINERS Sketch 1: FLEX / SAWA Equipment Location Page 44 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 PILGRIM FLEX 86KW GENERATOR PILGRIM FLEX 150KW GENERATOR F480VAC OPH (NOTES 1, 2, 3) 7 [ 80VAC3PH (NOTES 1, 2, 3)]

I(T150KW B N, , ,o L j 3OOA~

I ~J PWR D1ST 240/120V L IJ PWR DIST 240/120V FLEX GENERATOR SUPPORTING 125VDC &: 250VDC BATTTERY CHARGERS FLEX GENERATOR SUPPORTING 125VDC BATTTERY CHARGER 120VAC PANEL Y4/Y41 &: BATTERY ROOM FAN 120VAC PANFl Y3/Y31 &: RATTFRY ROOM FAN Sketch 2: FLEX / SAWA Power Distribution Page 45 of 50

Pilgrim Nuclear Power Station (PN PS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 4: Failure Evaluation Table Refer to the EA- 13-109 Phase 1 Overall Integrated Plan.

Page 46 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015, Attachment 5: References

1. Regulatory Documents A. Generic Letter 89-16, Installation of a Hardened Wetwell Vent, dated September 1, 1989 B. Order EA-12-049, Mitigation Strategies for Beyond-Design-Basis External Events, dated March 12, 2012 C. Order EA-12-050, Reliable Hardened Containment Vents, dated March 12, 2012

0. Order EA-12-051, Reliable SEP Level Instrumentation, dated March 12, 2012 E. Order EA-1 3-1 09, Severe Accident Reliable Hardened Containment Vents, dated June 6, 2013 F. JLD-ISG-2012-01, Compliance with Order EA-12-049, Mitigation Strategies for Beyond-Design-Basis External Events, dated August 29, 2012 G. JLD-ISG-2012-02, Compliance with Order EA-12-050, Reliable Hardened Containment Vents, dated August 29, 2012 H. JLD-ISG-2013-02, Compliance with Order EA-13-1 09, Severe Accident Reliable Hardened Containment Vents, dated November 14, 2013 I. NRC Responses to Public Comments, Japan Lessons-Learned Project Directorate Interim Staff Guidance JLD-!SG-2012-02: Compliance with Order EA-12-050, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents, ADAMS Accession No. ML12229A477, dated August 29, 2012 J. NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, Revision 1, dated August 2012 K. NEI 13-02, Industry Guidance for Compliance with Order EA-1 3-109, Revision 1, Dated April 2015 L. NEI 13-06, Enhancements to Emergency Response Capabilities for Beyond Design Basis Accidents and Events, Revision 0, dated March 2014 M. NEI 14-01, Emergency Response Procedures and Guidelines for Extreme Events and Severe Accidents, Revision 0, dated March 2014 N. NEI FAQ HCVS-01, HCVS Primary Controls and Alternate Controls and Monitoring Locations

0. NEI FAQ HCVS-08, HCVS Instrument Qualifications P. NEI FAQ HCVS-09, Use of Toolbox Actions for Personnel Q. NEI White Paper HCVS-WP-02, HCVS Cyclic Operations Approach R. NEI White Paper HCVS-WP-04, FLEX/HCVS Interactions S. NUREG/CR-71 10, Rev. 1, State-of-the-Art Reactor Consequence Analysis Project, Volume 1: Peach Bottom Integrated Analysis Page 47 of 50:

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 T. SECY-1 2-01 57, Considerationof Additional Requirements for Containment Venting Systems for Boiling Water Reactors with Mark I and Mark II Containments, 11/26/12 U. PNPS ESAR, Rev. 28, Final Safety Analysis Report V. JLD-ISG-2015-01, Compliance with Phase 2 of Order EA-13-1 09, Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions, dated March 2015 W. NEI HCVS-FAQ-10, Severe Accident Multiple Unit Response X. NEI HCVS-FAQ-1 1, Plant Response During a Severe Accident Y. NEI HCVS-FAQ-12, Radiological Evaluations on Plant Actions Prior to HCVS Initial Use Z. NEI HCVS-FAQ-1 3, Severe Accident Venting Actions Validation

2. Standards A. IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1 E Equipment for Nuclear Power Generating Stations,

3. Overall Integrated Plans A. PNPS EA-12-049 (FLEX) Overall Integrated Implementation Plan, Rev 0, February 2013 B. PNPS EA-13-109 (HCVS) Overall Integrated Implementation Plan, Rev 0, June 2014

4. Calculations A. Calculation M1380, Rev. 0, PNPS FLEX Strategy Thermal-Hydraulic Analysis

5. Procedures A. FSG 5.9.2.4, Rev. 0, FLEX Low Pressure Injection - Seawater through CST Inj~ection Point to RPV

6. Engineering Change Packages A. EC-42259, Rev. 0, PNPS FLEX Strategy Master EC For Beyond-Design-Basis External Events (BDBEEs) Diverse & Flexible Coping Strategy (Flex)

Implementation B. EC-45555, Rev. 0, FLEX Alternate Power To 125 VDC and 250VDC Battery Chargers (Base EC)

C. EC-45556, Rev. 0, FLEX Alternative Power To 120 VAC Panels (Base EC)

Page 48 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 6: Changqes/Updates to this Overall Integrated Implementation Plan This Overall Integrated Plan has been updated in format and content for Phase 2 of Order EA-13-109. Any significant changes to this plan will be communicated to the NRC staff in the 6 Month Status Reports.

Page 49 of 50

Pilgrim Nuclear Power Station (PNPS)

Hardened Containment Vent System (HCVS)

Phase 2 Overall Integrated Plan - December 2015 Attachment 7: List of Overall Integrated Plan Open Items Phase 1 and ISE Open Items are addressed as part of the Phase 10OIP updates.

Phase 2 Open Item Action Comment 1 No Open Items Page 50 of 50

ATTACHMENT 3 To PNPS Letter 2.15.082 Pilgrim Nuclear Power Station's Responses to Phase 1 Interim Staff Evaluation Open Items (6 pages)

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Response to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The PNPS HCVS is capable of venting the equivalent of (1) percent of licensed/rated thermal power and the Torus is capable of absorbing the decay heat from full power to (1) one percent licensed/rated thermal power to maintain the integrity of primary containment.

Make available for NRC staff audit analyses Calculations M 1387 "Hardened Containment Vent Capacity" and M 1380 demonstrating that HCVS has the capacity to vent "PNPS FLEX Strategy Thermal-Hydraulic Analysis" together validate the the steam/energy equivalent of one (1) percent of vent capacity for 1% licensed/rated thermal power at Containment Design licensed/rated thermal power (unless a lower value is Pressure (56 psig) and at the expected actual peak Wetwell venting justified), and that the suppression pool and the Section 3.2.2.1 conditions (Containment Design Temperature of 281 0F at the Saturation HCVS together are able to absorb and reject decay Section 3.2.2.2 Pressure of 35 psig). The analysis of the Suppression Pool (Torus) heat, such that following a reactor shutdown from capacity, temperature, and overall thermal balance when using Torus full power containment pressure is restored and then Venting for Containment Heat Removal, including reduced venting maintained below the primary containment design capacities at lower pressures and the net change to Torus water inventory, pressure and the primary containment pressure limit, is all included in Calculation M 1380. These Calculations were issued as a part of the PNPS FLEX Modification, Engineering Change (EC) 42259 and associated EC 46812. These documents are available for NRC Review on the ePortal.

EA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pge1o6 Page 1 of 6

Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Response to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The PNPS HCVS utilizes the Main Stack for discharge. In accordance with the PNPS FSAR (12.2.1.2) the Main Stack is a PNIPS Class I structure, as part of Secondary Containment System. As noted within the FSAR, portions of the Secondary Containment System are not designated to be functional during or after a tornado and, as such, the Main Stack was designed for the anticipated sustained high wind loads but not specifically Make available for NRC staff audit the seismic anddeindtwthadexrmtoaowndldng 2 tornado missile final design criteria for the HCVS Section 3.2.2.3 Seismic and sustained wind loading are included in the design criteria for stack. Section 3.2.11 the Main Stack and, in this application, the high wind loads were indicated as the controlling parameter for the stack design.

Calculation C15.0.3360 documents a review of the design basis requirements, design criteria, and acceptance criteria for the Main Stack and this analysis was performed to assess the stack to ensure compliance with FSAR design basis requirements. This document is available for NRC Review on the ePortal.

The HCVS Phase 1 design change package, along with supporting calculations, will identify the anticipated conditions during ELAP and a Severe Accident and confirm the capability for operating personnel to Section 3.2.1 safely access and operate controls and support equipment. The FLEX, Sein3.2.2.4 HCVS, and Severe Accident strategies anticipate or plan activities only in Makeavalabe fr NC saffaudt a evluaionof ection3.2.2.5 readily accessible areas of Secondary Containment. These areas are well Makeavalabe NR stff frudi an valatin o Secion3.22.5 shielded and contain the alternate locations for instrument indications and temperature and radiological conditions to ensure Section 3.2.2.1 bcu irgn(2 upisfrHV n aeyRle av SV that operating personnel can safely access and Section 3.2.4.1 bcu irgn(2 upisfrHV n aeyRle av SV operate controls and support equipment. Section 3.2.4.2 operation. There are no required activities in the Torus Compartment, Section 3.2.5.2 RJTR Quad Rooms, TIP Room, or other high radiation dose areas. Areas Secton 32.6 that may have elevated dose rates following core damage or RPV breach are only considered accessible for potential activities early in the ELAP, when dose rates are still in the normal range. This includes localized areas that have line-of-sight exposure to HCVS vent piping.

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Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp*onse to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The planned HCVS design utilizes the Main Stack as the discharge point.

The top of the Main Stack is at elevation 400 feet. The next highest plant structure is the stack tower structure attached to the Reactor Building. The 4 Prvd ecitoProvde decripionconirmng ofrigta tat heh CVSstack CS Section 3.2.2.3 exhausttower duct.structure The top houses the auxiliaryi of the weather boilerthestack, cap, over and theexhaust ventilation ventilation duct, discargs min t a ointaboe lantstrctues.is at approximately elevation 190 feet. The distance from the vent stack centerline to the centerline of the Reactor, is approximately 700 feet.

Refer to PNPS site drawings FLEX-01, M22, M28, & C332A.

The required instrumentation and controls (existing and new) are identified on page 18 of the PNPS HCVS OIP (June 2014). The existing instrumentation relied upon by HCVS provide indication of DryweUl &

Make available for NRC staff audit descriptions of Wetwell Pressure, Wetwell Level & Temperature, Reactor Pressure and all ad ad cntrls nstumetatin all nstumetatin cntros (xisingandHCVS (xis includn g Section 3.2.2.9 includesValve Position indication Indication. TheTemperature, proposed newSysteminstrumentation of HCVS Effluent Pressure, Flow planned) necessary to implement this order icung& Radiation Dose Rate, and Pneumatic Supply Pressure.

qualification methods. The PNPS HCVS detailed design is currently in progress. The design change package will issue documentation for the qualification of the components required for HCVS.

The proposed HCVS Battery System design criteria includes requirements for a minimum of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of operation with no recharging. The alternate Section 3.2.2.4 power source for the Battery Charger / Power Supply will be provided by a Sectin 3..3.1 FLEX Diesel Generator before the end of the initial 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, which Makeavalabe NR stff fr udi thefinl szin Secion3.23.2 will extend the operation of the HCVS instrumentation indefinitely.

6 evaluation for HICVS batteries/batteryintoFLEXDG charger oadig Section Setio 3.2.4.1 3.24.2 The part PNPS FLEX FLEX of thethe PNPS Generator loading calculation, Modification, PS262, was issued ECs,astoa including incorporation inoFE GlaigScin3242 establish capacity requirements for EC the 42259 FLEX and associated Generators. This calculation. Section 3.2.5.1 document is available for NRC Review on the ePortal. Analyses to Sectin 3..5.2 establish the required capacity of the HCVS Battery System and any Secton 32.6 required updating of the FLEX DG loading calculation will be issued as part of the detailed HCVS Phase 1 design change package.

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Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp*onse to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response Section 3.2.2.4 Section 3.2.3.1 Calculation M1386 "HCVS Vent Valves AO-5025 and AO-5042B Backup Section 3.2.3.2 N2 System" and Drawing C3102 were issued as a part of the PNPS FLEX Makte aCVa iablefrnCstf anudaic yte douentaion Section 3.2.4.1 Modification, EC 42259 and associated EC 46820, to establish theHCVS 7 ontroen th HCSneuati sytemdesgn Section 3.2.4.2 Nitrogen System design. These documents are available for NRC Review including sizing and location. Section 3.2.5.1 on the ePortal.

Section 3.2.5.2 Section 3.2.6 Make available for NRC staff audit the descriptions ofmlocal)condtionsp(temperaureg rLAditoand svreto ... The PNPS HCVS detailed design change package, along with supporting humiity antcipteddurig EAP nd sver Setion3.22.3 calculations, will finalize the anticipated conditions during ELAP events accident for the components (valves, Section 3.2.2.5 and a Severe Accident and confirm the capability of the components to 8 instrumentation, sensors, transmitters, indicators, Section 3.2.2.9 pefrthifucon.TeEwllasisedcmnainaddsus electronics, control devices, etc.) required for HCVS Sectionpefrthifucon.TeEwllasisedcmnainaddsus venting including confirmation that the components 3.2.2.10 the qualification of any new components required for HCVS.

are capable of performing their functions during ELAP and severe accident conditions.

Makeavalabl NRCstaf auitfo ocumntaionThe EP-Communications (EP-Comms) design change package has been that demonstrates adequate communication between implemented in support of the PNPS FLEX modifications. The HCVS 9 the remote HCVS operation locations and HCVS Section 3.2.2.5 design change package will evaluate the EP-Commns equipment required to decision makers during FLAP and severe accident support the HCVS. There are no significant changes anticipated for the conditions. EP-Comms capabilities that were established for the FLEX Strategy.

Calculation Ml1388 "HCVS Unintended Cross Flow Evaluation" was Make available for NRC staff audit descriptions of issued as part of the PNPS FLEX Modification, EC 42259 and associated design details that minimize unintended cross flow EC 46812, to address this requirement for the FLEX Strategy. The PNPS 10 of vented fluids within a unit including: the final Section 3.2.2.7 HCVS detailed design is currently in progress. This calculation will be method to isolate HCVS from SBGT, all interfacing updated as-needed for Severe Accident/FLAP conditions as part of the discharges to the plant stack, and control of all HCVS design change package. This document is available for NRC penetrations to the HCVS envelope. Review on the ePortal.

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Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp*onse to Phase 1 Interim Staff Evaluation Open Items 01 # Action ISE Section PNPS Response The PNPS HCVS detailed design is currently in progress. The PNPS FLEX, HCVS, and Severe Accident mitigation strategies prevent exceeding the design capabilities of Primary Containment by initiating Torus Venting at or before exceeding the Torus Bottom Pressure Primary Containment Pressure Limit (PCPL) value of 60 PSIG. Calculation M1380 "PNPS FLEX Strategy Thermal-Hydraulic Analysis" evaluates the Severe Accident Hydrogen (H2) production and shows that saturated steam temperature & pressure will combine with the H2 and N2 gas pressurization up to the Maximum Allowable Working Pressure (MAWP) for the Torus at 62 psig for the Short-Term Station Blackout (STSBO)

Case, which is based on the minimum time before core damage and RIPV Make available for NRC staff audit documentation breach. There is a potentially higher peak pressure of 82 psig for the of an evaluation verifying the existing containment Long-Term Station Blackout (LTSBO) Case, where core damage and 11 isolation valves, relied upon for the HCVS, will open Section 3.2.2.9 overheating occur later, after some time period on the order of 8 eight under the maximum expected differential pressure hours or longer during which there is successful operation of RCIC or during BDBEE and severe accident wetwell venting. HPCI for core cooling, then the H2 gas pressure and N2 gas pressure, together with the saturated steam pressure at that point in time, can significantly exceed the Torus Bottom Pressure PCPL value of 60 PSIG when the Wetwell is at 281°0F, although the Drywell Head Leakage Pressure Limit of 80 PSIG is not exceeded if Wetwell Venting is initiated at that time, which would be expected based on the use of EOPs or SAGs.

It is considered that, as soon as H2 gas evolution begins and the Torus Bottom Pressure approaches the PCPL value of 60 psig, Wetwell Venting will be initiated and will mitigate the peak pressure that occurs with continued H2 generation. This document is available for NRC Review on the ePortal.

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Pilgrim Nuclear Power Station's Interim Staff Evaluation Open Items Attachment 3 - Resp3onse to Phase 1 Interim staff Evaluation Open Items 01 # Action ISE Section PNPS Response The HCVS will be utilized to maintain the pressure within the containment Primary Containment Pressure Limit (PCPL), in accordance with EOPs and SAGs. This will minimize any leakage through containment Provide a description of the strategies for hydrogen penetrations and associated primary containment isolation valves. The 12 cntrlthtatpoental iniize or ydrgengasSecion3.22.6 HCVS piping is of welded construction and the number of boundary migratiotand mingriesst the roeactiaorbuidiognga orton32.. valves is minimized. Potential leakage from HCVS boundary isolation other buildings, valves will be addressed for Severe Accident conditions including consideration of hydrogen and combustible gases and radiological isotopes as part of the HCVS design change package. The PNPS HCVS detailed design is currently in progress.

References to be placed on ePortal:

[1] Calculation M1380 Rev 0 PNPS FLEX STRATEGY THERMAL-HYDRAULIC ANALYSIS

[2] Calculation M1386 Rev 0 HCVS Vent Valves A0-5025 and A0-5042B Backup N2 System

[3] Calculation M1387 Rev 0 Hardened Containment Vent Capacity

[4] Calculation M1388 Rev 0 HCVS Unintended Cross Flow Evaluation

[5] Calculation C1 5.0.3360 Rev 1 MAIN STACK STRUCTURAL EVALUATION

[6] Calculation PS262 Rev 0 FLEX Diesel Generator Loading

[7] Drawing FLEX-01 Rev 0 PNPS FLEX EQUIPMENT LAYOUT

[8] Drawing M22 Rev7 EQUIPMENT LOCATION REACTOR BUILDING SECTION CC

[9] Drawing M28 Rev 8 EQUIPMENT LOCATION MAIN STACK & FILTER BUILDING PLANS & SECTIONS

[10] Drawing C332A Rev 10 MISCELLANEOUS STRUCTURES STACK PLAN, ELEVATION & DETAILS

[11] Drawing C3102 Rev 0 (EC46820) N2 CYLINDER SUPPORT BACKUP N2 SUPPLY TO AO-5025 & AO-5042B FA-1 3-1 09 PNPS ISE Open Item Responses 12-04-2015Pae6o6 Page 6 of 6