ML17286A263

EA-13-109 Vent Order Audit Report

ML17286A263
Person / Time
Site:	Nine Mile Point
Issue date:	10/17/2017
From:	Rajender Auluck Beyond-Design-Basis Engineering Branch
To:	Bryan Hanson Exelon Generation Co
Lee B
References
CAC MF4482, EA-13-109, EPID L-2014-JLD-004
Download: ML17286A263 (24)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 October 17, 2017

SUBJECT:

NINE MILE POINT NUCLEAR STATION, UNIT 2 - REPORT FOR THE AUDIT OF LICENSEE RESPONSES TO INTERIM STAFF EVALUATION OPEN ITEMS RELATED TO NRG ORDER EA-13-109 TO MODIFY LICENSES WITH REGARD TO RELIABLE HARDENED CONTAINMENT VENTS CAPABLE OF OPERATION UNDER SEVERE ACCIDENT CONDITIONS (CAC NO. MF4482; EPID L-2014-JLD-004)

Dear Mr. Hanson:

On June 6, 2013 (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML13143A334), the U.S. Nuclear Regulatory Commission (NRG) issued Order EA-13-109, "Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Condition," to all Boiling Water Reactor licenses with Mark I and Mark II primary containments. The order requirements are provided in to the order and are divided into two parts to allow for a phased approach to implementation. The order required licensees to submit for review overall integrated plans (OIPs) that describe how compliance with the requirements for both phases of Order EA-13-109 will be achieved.

By letter dated June 27, 2014 (ADAMS Accession No. ML14184B340), Exelon Generation Company, Inc. (the licensee) submitted its Phase 1 OIP for Nine Mile Point Nuclear Station, Unit 2 (NMP2). By letters dated December 16, 2014, June 30, 2015, December 15, 2015 (which included the combined Phase 1 and Phase 2 OIP), June 30, 2016, December 14, 2016, and June 30, 2017 (ADAMS Accession Nos. ML14356A192, ML15181A017, ML15364A075, ML16182A013, ML16349A033, and ML17181A033, respectively), the licensee submitted its 6-month updates to the 01 P. The staff reviewed the information provided by the licensee and issued interim staff evaluations (ISEs) for Phase 1 and Phase 2 of Order EA-13-109 for NMP2 by letters dated February 11, 2015 (ADAMS Accession No. ML15028A149), and August 25, 2016 (ADAMS Accession No. ML16223A853), respectively. When developing the ISEs, the staff identified open items where the staff needed additional information to determine whether the licensee's plans would adequately meet the requirements of Order EA-13-109.

The NRG staff is using the audit process described in the letters dated May 27, 2014 (ADAMS Accession No. ML14126A545), and August 10, 2017 (ADAMS Accession No. ML17220A328),

to gain a better understanding of licensee activities as they come into compliance with the order.

As part of the audit process, the staff reviewed the licensee's closeout of the ISE open items.

The NRC staff conducted teleconferences with the licensee on November 17, 2016, and September 28, 2017. The enclosed audit report provides a summary of that aspect of the audit.

If you have any questions, please contact me at 301-415-1025 or by e-mail at Rajender.Auluck@nrc.gov.

Docket No.: 50-41 O

Enclosure:

Audit report cc w/encl: Distribution via Listserv Sincerely, Rajender Auluck, Senior Project Manager Beyond-Design-Basis Engineering Branch Division of Licensing Projects Office of Nuclear Reactor Regulation

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 AUDIT REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION AUDIT OF LICENSEE RESPONSES TO INTERIM STAFF EVALUATION OPEN ITEMS RELATED TO ORDER EA-13-109 MODIFYING LICENSES WITH REGARD TO RELIABLE HARDENED CONTAINMENT VENTS CAPABLE OF BACKGROUND OPERATION UNDER SEVERE ACCIDENT CONDITIONS EXELON GENERATION COMPANY. INC.

NINE MILE POINT NUCLEAR STATION, UNIT 2 DOCKET NO. 50-410 On June 6, 2013 (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML13143A334), the U.S. Nuclear Regulatory Commission (NRG) issued Order EA-13-109, "Order to Modify Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Condition," to all Boiling Water Reactor (BWR) licenses with Mark I and Mark II primary containments. The order requirements are divided into two parts to allow for a phased approach to implementation.

Phase 1 of Order EA-13-109 requires license holders of BWRs with Mark I and Mark II primary containments to design and install a Hardened Containment Vent System (HCVS), using a vent path from the containment wetwell to remove decay heat, vent the containment atmosphere (including steam, hydrogen, carbon monoxide, non-condensable gases, aerosols, and fission products), and control containment pressure within acceptable limits. The HCVS shall be designed for those accident conditions (before and after core damage) for which containment venting is relied upon to reduce the probability of containment failure, including accident sequences that result in the loss of active containment heat removal capability or extended loss of alternating current power (ELAP). The order required all applicable licensees, by June 30, 2014, to submit to the Commission for review an overall integrated plan (OIP) that describes how compliance with the Phase 1 requirements described in Order EA-13-109 Attachment 2 will be achieved.

Phase 2 of Order EA-13-109 requires license holders of BWRs with Mark I and Mark II primary containments to design and install a system that provides venting capability from the containment drywell under severe accident conditions, or, alternatively, to develop and implement a reliable containment venting strategy that makes it unlikely that a licensee would need to vent from the containment drywell during severe accident conditions. The order required all applicable licensees, by December 31, 2015, to submit to the Commission for Enclosure review an OIP that describes how compliance with the Phase 2 requirements described in Order EA-13-109 Attachment 2 will be achieved.

By letter dated June 27, 2014 (ADAMS Accession No. ML14184B340), Exelon Generation Company, Inc. (Exelon, the licensee) submitted its Phase 1 OIP for Nine Mile Point Nuclear Station, Unit 2 (NMP2). By letters dated December 16, 2014, June 30, 2015, December 15, 2015 (which included the combined Phase 1 and Phase 2 OIP), June 30, 2016, December 14, 2016, and June 30, 2017 (ADAMS Accession Nos. ML14356A192, ML15181A017, ML15364A075, ML16182A013, ML16349A033, and ML17181A033, respectively), the licensee submitted its 6-month updates to the OIP, as required by the order.

The staff reviewed the information provided by the licensee and issued interim staff evaluations (ISEs) for Phase 1 and Phase 2 for NMP2 by letters dated February 11, 2015 (ADAMS Accession No. ML15028A149), and August 25, 2016 (ADAMS Accession No. ML16223A853),

respectively. When developing the ISEs, the staff identified open items where the staff needed additional information to determine whether the licensee's plans would adequately meet the requirements of Order EA-13-109.

The NRC staff is using the audit process in accordance with the letters dated May 27, 2014 (ADAMS Accession No. ML14126A545), and August 10, 2017 (ADAMS Accession No. ML17220A328), to gain a better understanding of licensee activities as they come into compliance with the order. The staff reviews submitted information, licensee documents (via ePortals), and preliminary Overall Program Documents (OPDs)/OIPs, while identifying areas where additional information is needed. As part of this process, the staff reviewed the licensee closeout of the ISE open items.

AUDIT

SUMMARY

As part of the audit, the NRC staff conducted teleconferences with the licensee on November 17, 2016, and September 28, 2017. The purpose of the audit teleconferences was to continue the audit review and provide the NRC staff the opportunity to engage with the licensee regarding the closure of open items from the ISEs. As part of the preparation for these audit calls, the staff reviewed the information and/or references noted in the OIP updates to ensure that closure of ISE open items and the HCVS design are consistent with the guidance provided in Nuclear Energy Institute (NEI) 13-02, Rev. 1 and related documents (e.g. white papers (ADAMS Accession Nos. ML14126A374, ML14358A040, ML15040A038 and ML15240A072) and frequently asked questions (FAQs, ADAMS Accession No. ML15271A148)) that were developed and reviewed as part of overall guidance development. The NRC staff audit members are listed in Table 1. Table 2 is a list of documents reviewed by the staff. Table 3 provides the status of the ISE open item closeout for NMP2. The open items are taken from the Phase 1 and Phase 2 ISEs issued on February 11, 2015, and August 25, 2016, respectively.

FOLLOW UP ACTIVITY The staff continues to audit the licensee's information as it becomes available. The staff will issue further audit reports for NMP2, as appropriate.

Following the licensee's declarations of order compliance, the licensee will provide a final integrated plan (FIP) that describes how the order requirements are met. The NRC staff will evaluate the FIPs, the resulting site-specific OPDs, as appropriate, and other licensee documents, prior to making a safety determination regarding order compliance.

CONCLUSION This audit report documents the staff's understanding of the licensee's closeout of the ISE open items, based on the documents discussed above. The staff notes that several of these documents are still preliminary, and all documents are subject to change in accordance with the licensee's design process. In summary, the staff has no further questions on how the licensee has addressed the ISE open items, based on the preliminary information. The status of the NRC staff 's review of these open items may change if the licensee changes its plans as part of final implementation. Changes in the NRC staff review will be communicated in the ongoing audit process.

Attachments:

1. Table 1 - NRC Staff Audit and Teleconference Participants

2. Table 2 - Audit Documents Reviewed

3. Table 3-ISE Open Item Status Table

Table 1 - NRC Staff Audit and Teleconference Participants Title Team Member Organization T earn Lead/Project Manaoer Raiender Auluck NRR/DLP Project Manager Support/Technical Support - Containment I Ventilation Brian Lee NRR/DLP Technical Support - Containment I Ventilation Bruce Heida NRR/DLP Technical Suooort - Electrical Kerby Scales NRR/DLP Technical Support-Balance of Plant Kevin Roche NRR/DLP Technical Support - l&C Steve Wyman NRR/DLP Technical Suooort-Dose John Parillo NRR/DRA

Table 2 - Audit Documents Reviewed ECP 13-000087 - Missile Evaluation N2-2014-004, "MAAP 4.0.6 Analysis of Nine Mile Point Unit 2 Loss of All AC Power Scenario with Succesful FLEX Short Term - Cases 1F19a, 1 F20a, and 1 F23a" A 10.1-P-050 Revision. 0, "Hardened Contaniment Vent Capacity" AX-515B, "Pipe Stress Calculation For Vent'N R.B. Air Cool & Purge Piping Lines From Penetration Z-48 To Penetration Z-51" A 10.1-P-053, Revision 0, Hardened Containment Vent Purge System Design Calculation" Procedure N2-0P-76, Revision 00300 - Plant Communications Calculation-ES-198-01-1.0, "Control Building Station Blackout Analysis" H21 C-114, "NMP2 Hardened Containment Vent System Dose Assessment" EC-206, "600VAC FLEX Phase II Portable 450kW Diesel Generator Sizing Calculation" Document No. 301-10001434 Design/Sesmic Report Weak Link Analysis Maximum Torque Calculation VENRPT-15-000013 - Seismic Qualifiaction Summary for Hardened Containment Vent Components ECP 13-000087 - Instrumentation & Controls N2-MISC-003, Revision 2, "MAAP Analysis to Support SAWA Strategy" ECP-17-000280-CN-001 - H21C-114, "Hardened Containment Vent System (HCVS)

Radiological Dose Analysis" BWROG-TP-008, "Severe Accident Water Addition Timing" BWROG-TP-011, "Severe Accident Water Management Supporting Evaluations"

ISE Open Item Number Requested Action Phase 1 ISE 01 1 Make available for NRC staff audit the seismic and tornado missile final design criteria for the HCVS stack.

Nine Mile Point Nuclear Station, Unit 2 Vent Order Interim Staff Evaluation Open Items:

Table 3 - ISE Open Item Status Table Licensee Response - Information NRC Staff Close-out notes provided in 6-month updates and on the ePortal Seismic Design of the outdoor HCVS The NRC staff reviewed the stack information provided in the 6-month updates and on the The HCVS piping contains ASME ePortal.

[American Society of Mechanical Engineers] Class 2, 3 and ANSI Calculation AX-5158 addresses

[American National Standards Institute]

the HCVS seismic qualification.

831.1 piping. The entire HCVS system The licensee evaluated the entire has been evaluated to Seismic Category I HCVS system to Seismic requirements in pipe stress calculation Category I, which is consistent AX-5158 consistent with the plants with the plants seismic design-seismic design-basis to comply with NEI basis.

13-02, Section 5.2 seismic design guidance. Per NRC letter dated May 9, The Engineering Change 2014 [ADAMS Accession No.

Package (ECP) addresses the ML14111A147], "

Subject:

Seismic HCVS Tornado Missile Screening and Prioritization Results Protection. The licensee's design Regarding Information Pursuant to Title is consistent with the endorsed 10 of the Code of Federal Regulations white paper and meets all of the 50.54(f) Regarding Seismic Hazard Re-tornado missile assumptions Evaluations for Recommendation 2.1 of identified in HCVS-WP-04.

the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi No follow-up questions.

Accident", the NRC concluded that NMP2 "screened out" of performing the seismic risk evaluation as part of the Containment Purge System (CPS)n-ICVS seismic analysis. Therefore, the more severe Safety Evaluation (SE) status Closed; Pending; Open (need additional information from licensee)

Closed

[Staff evaluation to be included in SE Section 3.2.2]

seismic load case (2 times theSSE) is not required as part of the BDB [beyond-design-basis] analysis of the CPS/HCVS system. Pipe stress calculation AX-515B is available on the ePortal for NRC review.

Missile Protection of the outdoor HCVS stack NEI 13-02, Section 5.1.1.6 requires that missile impacts are to be considered for portions of the HCVS. The Nuclear Energy Institute (NEI) issued a white paper, HCVS-WP-04, endorsed by the NRC, which provides a risk-informed approach to evaluate the threat posed to exposed portions of the HCVS by wind-borne missiles. The white paper concludes that the HCVS is unlikely to be damaged in a manner that prevents containment venting by wind-generated missiles coincident with an [extended loss of alternating current power (ELAP)] or LUHS, for plants that are enveloped by the assumptions in the white paper.

A NMP2 specific missile evaluation is documented in the Engineering Change Package (ECP) consistent with HCVS-WP-04. The conclusion of the evaluation is that NMP2 meets all of the tornado missile assumptions identified in HCVS-WP-04 and as such, supplementary protection is not required for the HCVS piping and components. The ECP missile evaluation is available on the eportal for NRC review.

Phase 1 ISE 01 2 Per the NMP2 Updated Final Safety The NRC staff reviewed the Closed Analysis Report Table 3.2-1 and Section information provided in the 6-Make available for NRC staff 3.8.4.1.9, the Reactor Building Track Bay month updates and on the

[Staff evaluation to be review documentation of a is a seismic, tornado protected structure.

ePortal.

included in SE Section determination of seismic The EC-045 Series of calculations and 3.2.2]

adequacy for the remote EC-045 Series of drawings also indicate The ROS is in a location that is operating station (ROS) that the Track Bay/Standby Gas readily accessible and seismically location in the Reactor Treatment Building is a Safety-Related, adequate, and appears to support Building Track Bay.

QA Cat I structure. In addition, the outer operation of the HCVS.

track bay doors are designed to withstand tornado missiles per door specification No follow-up questions.

S208G.

Phase 1 ISE 01 3 The HCVS was designed to have the The NRC staff reviewed the Closed capacity to vent the steam equivalent of a information provided in the 6-Make available for NRC staff decay heat rate of 1 % of the rated thermal month updates and on the

[Staff evaluation to be audit analyses demonstrating power at a pressure equivalent to the ePortal.

included in SE Section that HCVS has the capacity to lessor of containment design pressure or 3.1.2.1]

vent the steam/energy the PCPL consistent with NEI 13-02 In response to the staff's question equivalent of one percent of Section 4.1.1.1 guidance. The design regarding HCVS capacity, the licensed/rated thermal power pressure was used which is 45 psig [per licensee provided Calculation (unless a lower value is square inch gauge] at NMP2. This is A 10.1-A-050. This document justified), and that the equivalent to a flow rate of approximately confirmed that the size of the suppression pool and the 148,600 lbm/hr. The current design has wetwell portion of the HCVS (?. 12 HCVS together are able to been evaluated considering pipe inches in diameter) provides absorb and reject decay heat, diameter, length, and geometry as well as adequate capacity to meet or such that following a reactor vendor provided valve Cv's, and the exceed the order criteria.

shutdown from full power losses associated with a burst rupture containment pressure is disc. Calculation A 10.1-A-050 concludes No follow-up questions.

restored and then maintained that the design provides margin to the below the primary containment minimum required flow rate. Calculation design pressure and the A10.1-A-050 is available for NRC review primary containment pressure on the ePortal.

limit.

Additionally, MAAP [Modular Accident Analysis Program] 4.0.6 analyses in Calculation N2-2014-004 were performed to investigate the response of the NMP2 containment venting using the new HCVS vent parameters and the use of RPV

[reactor pressure vessel] alternate injection with assumed RCIC [reactor core isolation cooling] failure at 240°F in the suppression pool. The objective of the analysis was to understand the overall accident response signature and key containment (wetwell and drywell) thermal-hydraulic behavior. The MAAP analyses demonstrate that the suppression pool and the HCVS together are able to absorb and reject decay heat, such that following a reactor shutdown from full power containment pressure is restored and then maintained below the primary containment design pressure and the primary containment pressure limit.

Calculation N2-2014-004 is available for NRG review on the ePortal.

Phase 1 ISE 01 4 As required by Order EA-13-109, Section The NRG staff reviewed the Closed 1.2.11, the HCVS design will include an information provided in the 6-Provide a description of the Argon purge system that will be month updates and on the

[Staff evaluation to be final design of the HCVS to connected just downstream of the HCVS ePortal.

included in SE Section address hydrogen detonation isolation valve. It will be designed to 3.1.2.11]

and deflagration.

prevent hydrogen detonation downstream The licensee's design is of that valve. However, the Argon purge consistent with option 3 of the system is required to be used only if the endorsed white paper HCVS-WP-ELAP progresses to severe accident

03.

conditions which result in the creation of hydrogen. The Argon purge system will No follow-up questions.

have a switch for the control valve in the MGR to allow opening the purge for the designated time, but it will also allow for local operation in the ROS in case of a DC power or control circuit failure. The installed capacity for the Argon purge system will be sized for 6 purges within the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the ELAP. Evaluation N2-MISC-003, "MAAP Analysis to Support SAWA Strategy" shows that in a severe accident, NMP2 would not be expected to exceed 6 vent cycles in the first 24-hour period. The desiqn allows for Argon bottle replacement for continued operation past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The Argon purge system can also be used to breach the rupture disc. The MCR panel will include an indication of vent line pressure upstream of the disc to show when the disc has burst due to the increased Argon pressure.

Phase 1 ISE 01 5 At NMP2, the primary operating station for The NRC staff reviewed the Closed HCVS operation is located in the MCR. A information provided in the 6-Make available for NRC staff HCVS remote operating station (ROS) is month updates and on the

[Staff evaluation to be audit documentation that located in the RB Track Bay. The location ePortal.

included in SE Section demonstrates adequate was evaluated for habitability and 3.1.1.1]

communication between the accessibility during a severe accident.

The communication methods are remote HCVS operation Onsite communications will be performed the same as accepted in Order locations and HCVS decision using either the installed sound powered EA-12-049.

makers during ELAP and headset system or the 450 MHz radios in severe accident conditions.

the talk around mode, or a combination No follow-up questions.

thereof. A sound powered phone jack is available near the ROS to communicate with the rest of the plant.

Offsite communications will utilize fixed satellite phones in the Control Room and Technical Support Center {TSC). Both locations also have portable satellite phones staged.

Communications protocol for beyond design basis events are documented in CC-NM-118 and procedure N2-0P-76 which are available for NRC review on the ePortal.

These communication methods are consistent with FLEX communication practices at NMP2 and have been previously reviewed by the staff as documented in a communications safety assessment regarding NTTF Rec 9.3 Communications for NMP ([ADAMS Accession No. ML 131 OOA236)].

Phase 1 ISE 01 6 The December 2015 OIP update contains The NRC staff reviewed the Closed a more detailed description of how the information provided in the 6-Provide a description of the design addresses hydrogen detonation month updates and on the

[Staff evaluation to be strategies for hydrogen control and deflagration.

ePortal.

included in SE Section that minimizes the potential for 3.1.2.12]

hydrogen gas migration and Same response as Open Item #4.

The licensee's design appears to ingress into the reactor maintain hydrogen below building or other buildings.

flammability limits.

No follow-up questions.

Phase 1 ISE 01 7 Temperature Evaluation:

The NRC staff reviewed the Closed information provided in the 6-Make available for NRC staff Accessing HCVS equipment, following an month updates and on the

[Staff evaluation to be audit an evaluation of external event that results in an ELAP, will ePortal.

included in SE Sections temperature and radiological subject the operator to prevailing area 3.1.1.2 and 3.1.1.3]

conditions to ensure that temperatures. The majority of the The licensee stated that expected operating personnel can safely operator travel path from the MCR to the peak area temperature for the access and operate controls ROS is outdoors. Therefore, the travel MCR is 100°F, which is based on and support equipment.

path does not pose any habitability Calculation ES-198.

concerns, with respect to temperature.

The MCR and ROS are expected to The licensee stated that the ROS remain habitable, with respect to location has no vital equipment in temperature, during the event. During the the area that would be operating, ELAP, as with the station blackout, which would add to the heat load, normal ventilation systems are inoperable and the ROS location has a 20' and non-vital equipment is not vertical height, which will contributing to the area heat load.

moderate the area temperature.

Therefore, area temperatures in the MCR Additionally, the Track Bay door will be higher than that for normal to the outside can be opened to operation and likely more in line with that moderate the temperature, if for station blackout. The expected peak needed.

area temperature for the MCR is 100°F.

This is based on Calculation ES-198 Temperatures do not exceed 110 which predicts the control room heat-up degrees Fahrenheit (F°), which is following a station blackout. The area acceptable for long-term temperature for the ROS in the Track Bay personnel habitability.

is not expected to undergo any appreciable change as a result of the The total integrated radiological event. There is no vital equipment in the dose in the MCR and ROS during area that would be operating, adding to the sustained operating period the heat load, and the space has a 20' results in low operator dose, vertical height, which will moderate the which is based on Calculation area temperature. Additionally, the Track H21C-114.

Bay door to the outside can be opened to moderate the temperature, if needed.

The calculated mission doses associated with actions taken to Radiological Evaluation:

protect the public under severe accident conditions will not Radiological Calculation H21 C-114 has subject plant personnel to an been completed to provide assurance that undue risk from radiation personnel can safely operate the NMP2 exposure.

HCVS and respond to required ERO response actions during severe accident No follow-up questions.

conditions. Calculation was performed using NRC endorsed HCVS-WP-02 and HCVS-FAQ-12 methodologies.

Calculation H21 C-114 has been posted on the ePortal for NRC's review.

In accordance with the definition of sustained operations in NEI 13-02, the integrated radiation dose due to HCVS operation over a 7-day period was determined in Calculation H21 C-114. The 7-day dose determined in the calculation due to HCVS operation is a conservative maximum integrated radiation dose over a 7-day period with ELAP and fuel failure starting at reactor shutdown. For the sources considered and the methodology used in the calculation, the timing of HCVS vent operation or cycling of the vent will not create higher doses at personnel habitability and equipment locations (i.e., maximum doses determined in the calculation bound operational considerations for HCVS vent operation).

The operator travel path is designed to minimize the dose to the operator from shine off of the HCVS vent pipe on the west side of the Reactor Building. The dose rates along the majority of the path are heavily shielded from the HCVS vent pipe and would not be significant ( < 1 mR/hr). The dose rate between the Control Building and the Maintenance Building could be significant (several R/hr). However, the exposure to this dose rate would be for a few seconds and the accumulated dose would not be significant.

Peak maximum dose rates and 7 -day total integrated dose have been calculated for the POS and the ROS in Calculation H21 C-114. The radiation dose to personnel occupying defined habitability locations, resulting from HCVS operation are below the 5 rem acceptance criteria as shown below:

MCR: 7-day Total Integrated Dose= 4.1 rem ROS: 7-day Total Integrated Dose< 1 rem Therefore, during the 7 days of sustained operation for BDBEE [beyond-design-basis-external events], the predicted environmental and radiological conditions will be acceptable for the operators to gain access to areas required for HCVS operation in the MCR and ROS. The above referenced calculations are available on the ePortal for NRC review.

Phase 1 ISE 01 8 Batteries/Battery Charger Slzing:

The NRC staff reviewed the Closed information provided in the 6-Make available for NRC staff The new battery selected is a sixty (60) month updates and on the

[Staff evaluation to be audit the final sizing evaluation cell GNB battery, with the battery cells ePortal.

included in SE Section for HCVS batteries/battery connected in series to create 125VDC 3.1.2.6) charger including incorporation nominal voltage. The battery is a Valve The licensee stated that all into FLEX DG loading Regulated Lead Acid (VALA) type rated electrical power required for calculation.

for 104 ampere hours. The battery is operation of HCVS components is selected in accordance to IEEE [Institute provided by a dedicated HCVS of Electrical and Electronics Engineers]

battery charger and batteries.

485. The Battery Sizing Requirements indicates that based on 2.3 ampere The battery sizing requirements loading requirements for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> duty confirmed that the HCVS period, a minimum of a sixty (60) cell, batteries have a minimum 90.3 ampere hours battery is required to capacity capable of providing bound the required battery duty cycle and power for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without end-of cycle battery terminal voltage recharging, and therefore is requirements. The selected battery adequate.

capacity of 104 ampere-hours is more than the minimum required 90.3 ampere-The licensee revised the FLEX hours battery capacity. Therefore, the Diesel Generator Calculation (EC-selected battery is adequate.

206) to add the loads for the HCVS (including the new battery The battery charger is rated for 130 volts charger). The NRC staff nominal DC output voltage, 1 O amperes reviewed the revised calculation nominal DC output current, 120 volts AC and confirmed that with the input voltage and a current limit additional load added, it's still adjustment range of 50% - 120%. The within the capacity and capability battery/battery charger sizing of the NMP2 FLEX diesel requirements evaluation is available on generator.

the ePortal for NRC review.

No follow-up questions.

Incorporation into FLEX DG Loading Calculation:

Following a BOBE, the battery charger is expected to draw a maximum load of 2.9 kVA. This load will be credited in the NMP2 FLEX Portable Diesel Generator Calculation EC-206 which was revised to reflect the load addition of the battery charger. The additional load added is still within the capability of the NMP2 FLEX Diesel Generator and therefore, this change is acceptable. Calculation EC-206 is available on the ePortal for NRC review.

Phase 1 ISE 01 9 P&ID 061-D outlines the functional design Reviewed Calculation A 10.1-P-Closed of the pneumatic system. Calculation 051, Rev 0, "Nitrogen Make available for NRC staff A 10.1-P-051 determines the required Requirement for Operation of the

[Staff evaluation to be audit documentation of the amount of Nitrogen needed for the HCVS Valves." Calculation included in SE Section HCVS nitrogen pneumatic required number of vent cycles in a 24-determined that if the N2 bottles 3.1.2.6]

system design including sizing hour period.

are maintained above 1993 psig, and location.

they will have sufficient capacity to operate the HCVS for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Phase 1 ISE 01 10 New components related to HCVS The NRC staff reviewed the Closed operation are required to be designed to information provided in the 6-Make available for NRC staff operate following a seismic event. Most month updates and on the

[Staff evaluation to be audit documentation of a equipment came qualified or evaluated by ePortal.

included in SE Section seismic qualification evaluation the vendor. However, some equipment 3.2.2]

of HCVS components.

was purchased as commercial grade The licensee provided several (non-safety related) and was shake tested reports which demonstrate the in order to prove the components' ability seismic adequacy of the HCVS to withstand a bounding seismic event.

components. The staff reviewed these reports and confirmed that Qualification/evaluation documentation the components required for provided by the vendor, or test results HCVS venting remain functional from shake tests were compiled into a following a design basis single report for HCVS dedicated earthquake.

equipment (Ref. VENRPT-15-000013) with the exception of separate seismic No follow-up questions.

design reports for the PC IVs and HCVS pressure control valve 2CPS-AOV134.

These reports are available on the ePortal for NRC review.

Phase 1 ISE 01 11 Existing Instrumentation:

The NRC staff reviewed the Closed information provided in the 6-Make available for NRC staff Existing control room indications for month updates and on the

[Staff evaluation to be audit descriptions of all drywell pressure and wetwell level are ePortal.

included in SE Section instrumentation and controls used for HCVS venting operation.

3.1.2.8]

(existing and planned)

Containment pressure indication is ECP-13-000087-102-02 Rev 6 necessary to implement this needed to determine the need, timing and discusses the environmental order including qualification effectiveness of the venting operation conditions during an accident at methods.

following a BDBEE, in order to ensure the locations containing l&C that containment pressure does not components. The staff concluded exceed the containment design pressure that the environmental and/or the primary containment pressure qualification met the order limit (PCPL). Containment pressure is requirements.

displayed on indicator 2CMS*Pl2A (Division 1 ), which receives a pressure No follow-up questions.

signal from pressure transmitter 2CMS*PT2A; and recorder 2CMS*PR2B (Division 2), which receives a pressure signal from pressure transmitter 2CMS*PT2B. Wetwell level indication is needed to determine that the wetwell vent path is preserved. Wetwell level is displayed on indicator 2CMS*Ll9A (Division 1 ), which receives a level signal from level transmitter 2CMS*L T9A; and recorder 2CMS*LR9B (Division 2), which receives a level signal from level transmitter 2CMS*LT9B.

The FLEX Phase 2 primary strategy is to provide power using a FLEX generator to Division 1 600 VAC unit substation to maintain instrumentation power supply and the back-up is Division 2. Depending on availability, either loop may be used for containment pressure and wetwell level determination. Additionally, containment pressure and/or wetwell level can be obtained from a Transmation 1045 (or similar loop calibrator) at the associated transmitter or in the relay room panel.

New HC,VS Instrumentation and Controls:

The l&C scope for the HCVS is to display the following and to control the SOVs associated with the new primary containment isolation valves from new control room panel 2CEC-PNL801 located in the main control room. The SOVs are controlled via key-lock control switches.

• Isolation Valve Position Indication

• Temperature, Pressure and Radiation of the HCVS Pipe

• HCVS Purge System Supply Pressure (Local indication only)

• Battery Voltage New track bay control panel 2CPS-PNL 100 serves as the main power distribution for all l&C components.

A detailed description of existing and new I &C components including qualification methods is included in the Engineering Change Package and is available on the ePortal for NRC review.

Phase 1 ISE 01 12 The HCVS is located in Primary The NRC staff reviewed the Closed Containment, Secondary Containment, information provided in the 6-Make available for NRC staff the Reactor Building Track Bay, the month updates and on the

[Staff evaluation to be audit the descriptions of local Control Room, and outside the Reactor ePortal.

included in SE Section conditions (temperature, Building. Environmental conditions and 3.1.1.4]

radiation and humidity) impacts are evaluated in detail in the ECP-13-000087-102-02 Rev 6 anticipated during ELAP and Engineering Change Package (ECP).

discusses the environmental severe accident for the The ECP includes a listing of the conditions during an accident at components (valves, components in each area along with the the locations containing l&C instrumentation, sensors, corresponding environmental conditions components. The staff concluded transmitters, indicators, including temperature, radiation and that the environmental electronics, control devices, humidity. The ECP also includes a qualification met the order and etc.) required for HCVS detailed listing of environmental requirements.

ventinQ includinQ confirmation qualification requirements. The complete that the components are listing and information from the ECP is No follow-up questions.

capable of performing their available on the ePortal for NRC review.

functions during ELAP and severe accident conditions.

Phase 1 ISE 01 13 The existing containment isolation valves The NRC staff reviewed the Closed 2CPS*AOV109 and 2CPS*AOV111 were information provided in the 6-Make available for NRG staff replaced with new valves. Additionally, month updates and on the

[Staff evaluation to be audit documentation of an an HCVS containment pressure control ePortal.

included in SE Section evaluation verifying the valve (2CPS-AOV134) located 3.2.1]

existing containment isolation downstream of the containment isolation The licensee provided valves, relied upon for the valves was added to control vent flow calculations A 10.1-P-04 7 and HCVS, will open under the after the containment isolation valves are A 10.1-P-052, which determined maximum expected differential opened during a BDBEE. Actuator actuator capability and margin pressure during BDBEE and capability and margin calculations were calculation. Based on these severe accident wetwell performed using the Sargent & Lundy calculations, the new air operated venting.

AirBase software program for the three valves (AOVs) can open under AOVs. The calculations are intended to the maximum expected confirm that the AO Vs can open under the differential pressure during a maximum expected differential pressure BDBEE and severe accident (MEDP) during BDBEE and severe wetwell venting.

accident wetwell venting.

No follow-up questions.

Under an ELAP or for severe accident wetwell venting the subject valves are closed and without their normal supply of air power. Prior to exceeding the primary containment pressure limit (PCPL),

Operators open the valves remotely using the dedicated HCVS batteries and nitrogen bottles. The MEDP is determined based on assuming the maximum upstream pressure is equal to the PCPL of 45 psig and by conservatively using a downstream pressure equal to vacuum pressure (-14.7 psig) since exhausting steam may condense in the HCVS line, creating a negative pressure. Thus the MEDP used in the calculations is 59.7 psid.

Calculation A 10.1-P-047 for 2CPS*AOV109/111 shows actuator torque required vs. actuator torque available margins for the closed to full open stroke in the range of 49% to 189%.

Calculation A 10.1-P-052 for 2CPS-AOV134 shows margins from the closed to full open stroke in the range of 78% to 233%. The calculations demonstrate positive margin in the opening direction.

The calculations are available on the ePortal for NRC review.

Phase 2 !SE 01 1 Reference Plant Nine Mile QOint U2 The N RC staff reviewed the Closed Torus freeboard Total f reeboard information provided in the 6-Licensee to provide the site-Volume is 525,000 volume is 782,00 month updates and on the

[Staff evaluation to be specific MAAP evaluation that gallons gallons ePortal.

included in SE Section establishes the initial SAWA SAWA flow is 500 SAWA flow is 300 4.2.1.1]

flow rate.

GPM at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> GPM at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Calculation N2-MISC-003. Cases followed by 1 00 followed by 1 00 2 through Case 2d address GPM from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> GPM from 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> SAWA and the ability to maintain to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> containment integrity. All Cases assume wetwell venting at 45 NMP2 has performed a plant specific psig. Cases 2, 2a, and 2d MAAP analysis to establish an initial assume 300 gallons per minute SAWA flow rate using the above (gpm) water addition at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> parameters of 300 GPM at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> followed by a reduction to 1 00 followed by 100 G PM from 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> to gpm 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> later. Case 2b 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br />. The MAAP analysis assumed 500 gpm water addition demonstrates that the plant is bounded by at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> followed by a reduction the reference plant analysis and that the to 100 gpm 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> later. All SAWM strategy is successful in making it Cases run show that sufficient unlikely that a drywell vent is needed to water is added to maintain or prevent containment failure (N2-MISC-increase the water level in the 003 Rev 2). The MAAP analysis is loaded suppression pool. All Cases run on the ePortal for NRG review.

demonstrate a successful SAWA strategy.

No follow-up questions.

Phase 2 ISE 012 The wetwell vent has been designed and The NRC staff reviewed the Closed installed to meet NEI 13-02 Rev 1 information provided in the 6-Licensee to demonstrate that guidance, which will ensure that it is month updates and on the

[Staff evaluation to be containment failure as a result adequately sized to prevent containment ePortal.

included in SE Sections of overpressure can be overpressure under severe accident 4.1 and 4.2]

prevented without a drywell conditions.

Calculation N2-MISC-003 Rev 2 vent during severe accident demonstrates a successful SAWA conditions.

The SAWM strategy will ensure that the strategy will maintain containment wetwell vent remains functional for the within design limits. The SAWM period of sustained operation. Nine Mile strategy will ensure that the Point Unit 2 will follow the guidance (flow wetwell vent remains functional rate and timing) for SAWA/SAWM for the period of sustained described in BWROG-TP-15-008 and operation.

BWROG-TP-15-011. The wetwell vent will be opened prior to exceeding the PCPL No follow-up questions.

value of 45 PSIG. Therefore, containment over pressurization is prevented without the need for a drvwell vent.

Phase 2 ISE 01 3 NMP2 utilizes the installed sound The NRG staff reviewed the Closed powered headset system and/or the 450 information provided in the 6-Licensee to demonstrate that MHz radios in the talk around mode to month updates and on the

[Staff evaluation to be there is adequate communicate between the MCA and the ePortal.

included in SE Section communication between the SAWA flow control location. This 4.1]

MCR and the operator at the communication method is the same as The communication methods are FLEX manual valve during accepted in Order EA-12-049. These the same as accepted in Order severe accident conditions.

items will be powered and remain EA-12-049.

powered using the same methods as evaluated under EA-12-049 for the period No follow-up questions.

of sustained operation, which may be longer than identified for EA-12-049.

Phase 2 ISE 01 4 The SAWA flow instrument will be The NRC staff reviewed the Closed mounted on the FLEX valve manifold cart information provided in the 6-Licensee to demonstrate the and stored in the reactor building just month updates and on the

[Staff evaluation to be SAWM flow instrumentation outside of the inner door to the reactor ePortal.

included in SE Sections qualification for the expected building track bay. During FLEX/SAW A 4.1.1.3 and 4.2.1.3]

environmental conditions.

flow injection to the RPV the cart will be ECP-17-000280-CN-001-moved into the RB track bay adjacent to H21 C114 Rev 0 discusses the the HCVS Remote Operating Station SAWM flow instrumentation (ROS). A quantitative evaluation of qualification. The NRG staff expected dose rates has been performed found through engineering per HCVS-WP-02 and found the dose judgement that the accuracy of rates at the ROS including ingress/egress the flow meter and the paths are acceptable (Ref. Calculation environmental qualifications H21C-114 as amended by ECP related to the performance of the 00280-CN-001 H21 C-114). The dose flow meter meet the intent of rate at the operating location of the flow 0 rder EA-13-109.

meter cart is <5E-3 rem/hr. The total dose over the 7-day period is less than 1 No follow-up questions.

rem, which is well below the generally accepted maximum for digital equipment, 1000 rem. The flow meter is commercial equipment and does not have a published radiation dose limit. ECP-17-00280-CN-001 H21 C-114 is loaded in the NRC ePortal.

The selected instrument is designed for the expected flow rate, temperature, and pressure for SAWA over the period of sustained operation.

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• via e-mail OFFICE NRR/DLP/PBEB/PM NRR/DLP/PBMB/LA NRR/DLP/PBEB/BC NRR/DLP/PBEB/PM NAME RAuluck Slent TBrown RAuluck DATE 10/16/2017 10/13/2017 10/17/2017 10/17/2017