ML17354B306
| ML17354B306 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 12/22/2017 |
| From: | Rajender Auluck Beyond-Design-Basis Engineering Branch |
| To: | Bryan Hanson Exelon Generation Co, Exelon Nuclear |
| Lee B | |
| References | |
| CAC MF4456, CAC MF4457, EA-13-109, EPID L-2014-JLD-0050 | |
| Download: ML17354B306 (21) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 22, 2017 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
LASALLE COUNTY STATION, UNITS 1 AND 2 - REPORT FOR THE AUDIT OF LICENSEE RESPONSES TO INTERIM STAFF EVALUATIONS OPEN ITEMS RELATED TO NRC ORDER EA-13-109 TO MODIFY LICENSES WITH REGARD TO RELIABLE HARDENED CONTAINMENT VENTS CAPABLE OF OPERATION UNDER SEVERE ACCIDENT CONDITIONS (CAC NOS. MF4456 AND MF4457; EPID L-2014-JLD-0050)
Dear Mr. Hanson:
On June 6, 2013 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML13143A334), the U.S. Nuclear Regulatory Commission (NRC) 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 licensees 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 30, 2014 (ADAMS Accession No. ML14184A016), Exelon Generation Company, LLC. (the licensee) submitted its Phase 1 OIP for LaSalle County Station, Units 1 and Unit 2 (LaSalle). By letters dated December 17, 2014, June 30, 2015, December 16, 2015 (which included the combined Phase 1 and Phase 2 OIP), June 30, 2016, December 14, 2016, and June 29, 2017 (ADAMS Accession Nos. ML14351A450, ML15181A226, ML15352A109, ML16182A394, ML16349A439, and ML17180A391, respectively), the licensee submitted its 6-month updates to the OIP. The NRC 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 LaSalle by letters dated March 31, 2015 (ADAMS Accession No. ML15084A180), and August 2, 2016 (ADAMS Accession No. ML 1611 OA368), 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 described in 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.
B. Hanson The NRC staff conducted a teleconference with the licensee on December 14, 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 email at Rajender.Auluck@nrc.gov.
Sincerely, Rajender Auluck, Senior Project Manager Beyond-Design-Basis Engineering Branch Division of Licensing Projects Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374
Enclosure:
Audit report cc w/encl: Distribution via Listserv
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 EVALUATIONS OPEN ITEMS RELATED TO ORDER EA-13-109 MODIFYING LICENSES WITH REGARD TO RELIABLE HARDENED CONTAINMENT VENTS CAPABLE OF OPERATION UNDER SEVERE ACCIDENT CONDITIONS EXELON GENERATION COMPANY, LLC LASALLE COUNTY STATION, UNITS 1 AND 2 DOCKET NOS. 50-373 AND 50-37 4 BACKGROUND On June 6, 2013 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML13143A334), the U.S. Nuclear Regulatory Commission (NRC) 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) licensees 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 30, 2014 (ADAMS Accession No. ML14184A016), Exelon Generation Company, LLC. (the licensee) submitted its Phase 1 OIP for LaSalle County Station, Units 1 and Unit 2 (LaSalle). By letters dated December 17, 2014, June 30, 2015, December 16, 2015 (which included the combined Phase 1 and Phase 2 OIP), June 30, 2016, December *14, 2016, and June 29, 2017 (ADAMS Accession Nos. ML14351A450, ML15181A226, ML15352A109, ML16182A394, ML16349A439, and ML17180A391, respectively), the licensee submitted its 6-month updates to the OIP, as required by the order.
The NRC 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 LaSalle by letters dated March 31, 2015 (ADAMS Accession No. ML15084A180), and August 2, 2016 (ADAMS Accession No. ML 1611 OA368), respectively. When developing the IS Es, 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 a teleconference with the licensee on December 14, 2017. The purpose of the audit teleconference 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 IS Es. 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 LaSalle. The open items are taken from the Phase 1 and Phase 2 ISEs issued on March 31, 2015, and August 2, 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 LaSalle, 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 Team Lead/Sr. Project Manaoer Rajender Auluck NRR/DLP Project Manager Support/Technical Support - Containment / Ventilation Brian Lee NRR/DLP Technical Support - Containment/
Ventilation Bruce Heida NRR/DLP Technical Support - Electrical Kerby Scales NRR/DLP Technical Support- Balance of Plant Kevin Roche NRR/DLP Technical Support - l&C Steve Wyman NRR/DLP Technical Support - Dose John Parillo NRR/DRA Attachment 1
Table 2 - Audit Documents Reviewed L-004114, "125 VDC Battery Sizing Calculation For Hardened Containment Vent System for 24 Hour Duty Cycle," Revision 0 EC 396062, Revision 4, DCS Section 4.1.35 - Electrical Requirements EC 396069, Revision 3, DCS Section 4.1.35 - Electrical Requirements L-004117, "HCVS Nitrogen Pressure Regulator Set Point & Bottle Capacity," Revision O (Unit 2)
L-004184, "HCVS Nitrogen Pressure Regulator Set Point & Bottle Capacity," Revision O (Unit 1)
L-004115, "HCVS Phase 1 Dose Assessment," Revision 2 EC 392353, Revision 5, DCS Section 4.1.14 - Environmental Conditions and Impacts L-004097, "Hardended Containment Vent Capacity," Revision 3 (Unit 2)
L-004149," Hardened Containment Vent Capacity," Revision O (Unit 1)
L-004092, "Evaluation of Reactor Building Exterior Structural Steel Tower," Revision 2A LOA-FSG-010, "FLEX Communications," Revision 3 LGA-VQ-202, "Emergency Containment Vent," Revision 1 LOP-PC-09," Hardened Containment Vent System (HCVS) Argon/Nitrogen Supply Operation,"
Revision 4 L-004137, "Hardened Containment Vent Purge System Design Calculation," Revision O (Unit 2)
L-004185, "Hardened Containment Vent Purge System Design Calculation," Revision O (Unit 1)
L-003953, "Seismic Qualification of FLEX Transfer Switch," Revision 1B L-004138, "Seismic Qualification of HCVS Battery System," Revision 0 L-004139, "Seismic Qualification of General Atomics RD-2B Detector/Shield Assmebly,"
Revision OA L-004140, "Sesmic Qualification of HCVS Isolation Vavles, Actuators and Wetwell Vent Valve Limit Swtches," Revsion 1 L-004141, "Seismic Qualification of Rosemount 3152N Pressure Transmitter in HCVS ROS Instrument Rack," Revision OA L-004142, "Seismic Qualification of ASCO 3-Way Solenoid Valve with 3/8" NPT Ports, Model No. NP8316A54E 125 VDC," Revision OA L-004143, "Seismic Qualification of Various Components for the Hardened Containment Vent System Modifications," Revision 0 L-004144, "Seismic Qualification of Continental Disc Corp. (CDC) HPX Rupture," Revision OA L-004145, "Sesimic Qualificaiton of Argon System 2-Way Leakoff Isolation Valve," Revision OA L-004146, "Seismic Qualification of Supervisory Master Station Panel OPM08J and Internal Components associated with the Hardened Containment Vent System," Revision 0 L-004161, "Seismic Qualification of RTD -Weed Model N9002D-1A-60-12," Revision OA L-004162, "Seismic Qualification of Kunkle Relief Valve Model 0541-A02AKM0150 For The Hardened Containment Vent System Modifications," Revision OA L-004163, "Seismic Qualification of AVCO Speed Control Valve Model U200A-45," Revision OA L-004164, "Seismic Qualification of Atkomatic Solenoid Valve 12430-003HPKEK1 E," Revision QA L-QQ4165, "Seismic Qualification of TESCOM Pressure Regulating Valves," Revision QA L-Q04166, "Seismic Qualification of Panels and Components Installed in Radiation Monitor Cabinets 1(2)PC321," Revision 1 EC 392353, Revision 5, DCS Section 4.1.36 - Instrument and Controls Requirements Attachment 2
L-004151, "HCVS FLEX Activities and Phase II Dose Assessment for Unit 1 and 2," Revision O BWROG-TP-008, "Severe Accident Water Addition Timing" BWROG-TP-011, "Severe Accident Water Management Supporting Evaluations"
LaSalle County Station, Units 1 and 2 Vent Order Interim Staff Evaluation Open Items:
Table 3 - ISE Open Item Status Table ISE Open Item Number Licensee Response - Information NRG Staff Close-out notes Safety Evaluation (SE) provided in 6 month updates and on the status Requested Action ePortal Closed; Pending; Open (need additional information from licensee)
Phase 1 ISE 01 1 Complete for Unit 2. The motive and The NRG staff reviewed the Closed purge gas systems will be isolated by at information provided in the 6-Make available for NRG staff least one locked-closed manual valve in month updates and on the [Staff evaluation to be audit documentation of a each system during normal operation. ePortal. included in SE Section method to disable HCVS Main Control Room (MGR) controls will be 3.1.2.7]
during normal operation to via key-locked switches with power Per the Phase 1/Phase 2 OIP provide assurances against normally de-energized. PCIVs [primary (December 2015), EOP/EPG inadvertent operation that also containment isolation valve] are air-to- operating procedures provide minimizes actions to enable open, spring/fail closed. clear guidance that the HCVS is HCVS operation following an not to be used to defeat ELAP. Ref. 9 (DCS 4.1.19, 4.1.33, 4.1.35, containment integrity during any 4.1.36) and procedure LGA-VQ-202 design-basis transients or provide direction for these actions and are accidents. In addition, inadvertent available on ePortal. actuation prevention features include two PCIVs in series and a In-progress for Unit 1 following the downstream rupture disc. These concept described for Unit 2, above. valves are fail-closed air operated valves (AOVs) (air-to-open, spring-to-close) that require energizing an SOV to allow the motive air/gas to open the valve.
Each PCIV is controlled by its own key-locked switch. In addition, the direct current (de) power to the solenoid-operated valve (SOV) and the motive gas supply, and purge gas supply will normally be disabled to prevent inadvertent operation.
Attachment 3
No follow-up questions.
Phase 1 ISE OI 2 Complete. Calculation L-004114 performs The NRC staff reviewed the Closed the sizing evaluation of the common information provided in the 6-Make available for NRC staff HCVS batteries and associated charger. month updates and on the [Staff evaluation to be audit the final sizing evaluation The results show a margin of ePortal. included in SE Section for HCVS batteries/battery approximately 7% after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with all 3.1.2.6]
charger including incorporation Unit 1 and Unit 2 HCVS loads drawing The licensee stated that all into FLEX DG [diesel maximum current. The FLEX DG loading electrical power required for generator] loading calculation. evaluations in ECs 396062 (DCS 4.1.35) operation of HCVS components is and 396069 (DCS 4.1.35) show a margin provided by the 125 volt (V) de on the more limited DG of 337 amps for battery/battery charger.
future loads. The HCVS battery charger rated input current is 8 amps per Ref. 9 The battery sizing calculation (L-(DCS 4.1.35). Therefore, there is 004114) confirmed that the HCVS sufficient margin in either FLEX DG to batteries have a minimum power the HCVS battery charger. capacity capable of providing power for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without L-004114, Revision 0, the Design recharging, and therefore is Consideration Summaries (DCSs) of the adequate.
final revisions of ECs 396062 and 396069, and Ref. 9 & 12 are available on The licensee provided DCS ePortal. Section 4.1.35 for EC's 396062 and 396069, which discusses re-powering of the HCVS battery charger using a FLEX DG.
No follow-up questions.
Phase 1 ISE 01 3 Complete. Pneumatic system motive The NRC staff reviewed the Closed force changed to nitrogen; see Section 4 information provided in the 6-Make available for NRC staff of this document, Ref. 9 (DCS 4.1.33), month updates and on the [Staff evaluation to be audit documentation of the and calculations L-004117 and L-004184 ePortal. included in SE Section HCVS argon pneumatic 3.1.2.6]
system design including sizing L-004117, L-004184 and Ref. 9 are EC 392353, DCS Section 4.1.33 and location. available on ePortal. discusses the pneumatic design and sizing. Calculations L-004117 and L-004184, "HCVS Nitrogen Pressure Regulator Set Point & Bottle Capacity," Revision O assumes the volume of nitrogen to cycle both vent valves once
and the outboard 7 additional times, which is sufficient 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 />.
No follow-up questions.
Phase 1 ISE 01 4 Complete. The radiological evaluation in The NRC staff reviewed the Closed calculation L-004115 and temperature information provided in the 6-Make available for NRC staff evaluation in Ref. 9 & 12 (DCS 4.1 .14) month updates and on the [Staff evaluation to be audit an evaluation of show no additional shielding or high ePortal. included in SE Sections temperature and radiological temperature mitigation is required to 3.1.1.2 and 3.1.1.3]
conditions to ensure that safely access and operate controls and EC 392353, Revision 5, DCS operating personnel can safely equipment. Section 4.1.14, Environmental access and operate controls Conditions and Impacts, and support equipment. L-004115 and Ref. 9 & 12 are available addresses the radiological and on ePortal. temperature conditions in the MCR, Remote Operating Station (ROS), and 4160-V Switchgear area.
Calculation L-003969, Rev. 0, "U1/U2 Transients Heat-Up Analysis for the Control Room, AEERs, Div. 1, and Div. 2 Switchgear Rooms following a BDBEE [beyond-design-basis external event]", was performed for Order EA-12-049. It determined that the Control Room, without mitigating actions, would not exceed 110°F until 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> into the event. With mitigating actions the Control Room would be at 108°F at 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> into the event.
The environmental evaluation in EC 392353 is a conservative maximum temperature for the ROS. A "toolbox" approach will be used by operators as
necessary for extreme temperature conditions (e.g.: ice vests, small portable fans, etc.)
per plant procedure LOA-FSG-005. In addition, operator stay time in the ROS will be limited.
Continuous occupancy of the ROS is not required.
Calulation L-004115, "HCVS Phase 1 Dose Assessment,"
Revision 2 was performed to determine the integrated radiation dose due to HCVS operation.
Temperature and radiological conditions should not inhibit operator actions needed to initiate and operate the HCVS during an ELAP with severe accident conditions.
No follow-up questions.
Phase 1 ISE 01 5 Complete. Calculation L-004097 and L- The NRC staff reviewed the Closed 004149 show that the HCVS has the information provided in the 6-Make available for NRC staff capacity to vent the steam/energy month updates and on the [Staff evaluation to be audit analyses demonstrating equivalent of 1 % of rated thermal power ePortal. included in SE Section that HCVS has the capacity to while maintaining containment pressure 3.1.2.1]
vent the steam/energy below containment design pressure and Calculations L-004097 and L-equivalent of one percent of PCPL [Primary Containment Pressure 004149 used a rated thermal licensed/rated thermal power Limit]. power of 4,068 MWt. The (unless a lower value is assumed containment pressure at justified), and that the L-004097 and L-004149 are available on start of venting is 38.1 per square suppression pool and the ePortal. inch gauge (psig), which is less HCVS together are able to than the drywell/wetwell design absorb and reject decay heat, pressure of 45 psig or the PCPL such that following a reactor of 60 psig. The minimum 1%
shutdown from full power thermal power venting capacity is containment pressure is 150,650 lbm/hr. The calculated restored and then maintained venting capacity at 38.1 psig is
below the primary containment 154,600 lbm/hr, which provides a design pressure and the 2.7% flow margin.
primary containment pressure limit. No follow-up questions.
Phase 1 ISE 01 6 Complete. LaSalle design complies with The NRC staff reviewed the Closed the reasonable tornado protection criteria information provided in the 6-Make available for NRC staff of Reference 6. The seismic and tornado month updates and on the [Staff evaluation to be audit the seismic and tornado missile protection design is described in ePortal. included in SE Section missile final design criteria for Ref. 9 (DCS 4.1.38) and evaluated in 3.2.2]
the HCVS stack. calculation L-004092. EC 392353, DCS Section 4.1.38 addresses the HCVS seismic Ref. 9 and L-004092 are available on qualification and tornado missile ePortal. design.
The licensee evaluated the entire HCVS system to Seismic Catergory I, which is consistent with the plants seismic design-basis.
For the tornado missile design the licensee performed Calculation L-004092, "Evaluation of Reactor Building Exterior Structural Steel Tower," Revision 2A. Based on the structural requirements for the support tower to withstand design basis wind generated missiles, the HCVS exiting the Reactor Building at greater than 30' above grade, and administrative controls controlling laydown of items which may become potential wind generated missiles, the licensee considers the HCVS has reasonable protection from wind generated missiles.
No follow-up questions.
Phase 1 ISE 01 7 Complete. Reference 9 & 12 (DCS The NRC staff reviewed the Closed 4.1 .14) include the tern perature and information provided in the 6-Make available for NRC staff humidity evaluations and calculation L- month updates and on the [Staff evaluation to be audit the descriptions of local 004115 evaluates the radiological ePortal. included in SE Section conditions (temperature, conditions. 3.1.1.4]
radiation and humidity) EC 392353, DCS Section 4.1.14 anticipated during ELAP and Ref. 9 & 12 and L-004115 are available discusses the environmental severe accident for the on ePortal. conditions during an accident at components (valves, the locations containing l&C instrumentation, sensors, components. The staff's review transmitters, indicators, indicated that the environmental electronics, control devices, qualification met the order and etc.) required for HCVS requirements.
venting including confirmation that the components are No follow-up questions.
capable of performing their functions during ELAP and severe accident conditions.
Phase 1 ISE 01 8 Complete. FLEX communications The NRC staff reviewed the Closed strategies and equipment (as described in information provided in the 6-Make available for NRC staff procedure LOA-FSG-010) will be utilized month updates and on the [Staff evaluation to be audit documentation that for HCVS. These methods are adequate ePortal. included in SE Section demonstrates adequate for HCVS implementation. 3.1.1.1]
communication between the The communication methods are remote HCVS operation LOA-FSG-010 is available on ePortal. the same as accepted in Order locations and HCVS decision EA-12-049.
makers during ELAP and severe accident conditions. No follow-up questions.
Phase 1 ISE 01 9 Complete. An argon purge system is The NRC staff reviewed the Closed provided which is designed to purge the information provided in the 6-Provide a description of the vent piping of a detonable mixture of month updates and on the [Staff evaluation to be final design of the HCVS to hydrogen and oxygen after each vent ePortal. included in SE Section address hydrogen detonation cycle. Installed capacity is provided for 3.1.2.11]
and deflagration. the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after ELAP, and Licensee uses Argon to purge the additional argon bottles are stored in a HCVS piping of hydrogen to limit FLEX building to continue operation past the possibility of a hydrogen 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. deflagration/detonation.
Calculations L-0014137 and L-004185 assumes the volume of
Calculation L-004137 & L-004185 and Argon to burst the rupture disk Ref. 9 & 12 (DCS 4.1.33), are available and 8 purges in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
on ePortal.
The licensee's design is consistent with Option 3 of the endorsed white paper HCVS-WP-03.
No follow-up questions.
Phase 1 ISE 0110 Complete. LaSalle wetwell vent line has a The NRG staff reviewed the Closed dedicated HCVS flowpath from the information provided in the 6-Provide a description of the wetwell penetration to the outside with no month updates and on the [Staff evaluation to be strategies for hydrogen control interconnected system. The discharge ePortal. included in SE Section that minimizes the potential for point meets the guidance of HCVS-FAQ- 3.1.2.12]
hydrogen gas migration and 04 (Att. J of Reference 3). See Ref. 9 The HCVS wetwell pipe in each ingress into the reactor (Dwg. M-138 Sheet 3), available on each unit provides a dedicated building or other buildings. ePortal. HCVS flowpath from the wetwell penetration PCIVs to the outside with no interconnected downstream piping. The staff's review of the proposed system indicates that the licensee's design appears to maintain hydrogen below flammability limits.
No follow-up questions.
Phase 1 ISE 01 11 Complete for Unit 2. See calculations L- The NRG staff reviewed the Closed 003953, L-004138 through L-004146, L- information provided in the 6-Make available for NRG staff 004161 through L-004166. month updates and on the [Staff evaluation to be audit documentation of a ePortal. included in SE Section seismic qualification evaluation All above calculations are available on 3.2.2]
of HCVS components. ePortal. The licesee provided several reports which demonstrate the In-progress for Unit 1; design will follow seismic adequacy of the HCVS the same concept as Unit 2. components. The staff reviewed these reports and confirmed that the components required for HCVS venting remain functional
following a design basis earthquake.
No follow-up questions.
Phase 1 ISE 01 12 Complete for Unit 2; Unit 1 design will The NRC staff reviewed the Closed follow the same concept as Unit 2, but not information provided in the 6-Make available for NRG staff calculation are approved. month updates and on the [Staff evaluation to be audit descriptions of all ePortal. included in SE Section instrumentation and controls New instrumentation and controls are 3.1.2.8]
(existing and planned) described in Reference 9 & 12 (DCS The existing plant instuments necessary to implement this 4.1.36), and qualification methods are per required for HCVS (i.e. wetwell order including qualification calculations shown in the table below. All level instruments and drywell methods. referenced documents are available on pressure instruments) meet the ePortal. requirements of RG 1.97.
Existing instruments relied upon for EC 392353, DCS Section 4.1 .36 initiation, operation, and monitoring of discusses the qualifications for HCVS are qualified or evaluated to new HCVS l&C components. The Regulatory Guide 1.97 and include the staff's review indicated that the following: Dryweil pressure (1 (2)PI- qualification met the order CM029), Wetwell pressure (1(2)PI- requirements.
CM056), Wetwell level (1 (2)LI-CM1 92),
Wetwell water temperature (1 (2)TI- No follow-up questions.
CM037), and Reactor pressure (1 (2)C61
-R01 1). (Ref. 9, DCS 4.1.14)
Phase 1 ISE 01 13 Complete for Unit 2. Procedures LGA-VQ- The NRG staff reviewed the Closed 202 and LOP-PC-09 contain all information provided in the 6-Make available for NRG staff instructions for operation of the HCVS. month updates and on the [Staff evaluation to be audit guidelines and ePortal. included in SE Section procedures for HCVS Above procedures are available on 5.1]
operation. ePortal. The guidelines and procedures for HCVS operation are complete In-progress for Unit 1; design will follow and consistent with the guidance the same concept as Unit 2. in NEI 13-02.
No follow-up questions.
Phase 2 ISE 01 1 Actions taken within the first hour (prior to The NRG staff reviewed the Closed start of core damage) from the start of the information provided in the 6-ELAP are acceptable from an
Licensee to confirm through environmental and radiological month updates and on the [Staff evaluation to be analysis the temperature and perspective without further evaluation. ePortal. included in SE Sections radiological conditions to 4.1.1.4 and 4.2.1.4]
ensure that operating Actions performed within the MCR are For temperature review of the personnel can safely access acceptable for the entire period of MCR and ROS see Open ltem-4 and operate controls and Sustained Operation per HCVS-FAQ-06 above. Actions outside the MCR support equipment. Assumption 049-21. or the ROS are performed at the Remote Shutdown Panel, in the For actions within the Reactor Building Diesel Generator Building and between 1 and 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />, a quantitative Corridors, and outside of the evaluation of expected dose rates has Diesel Corridors. As noted in been performed per HCVS-FAQ-12 and Open ltem-4, above, operators found the dose rates at deployment will use a "toolbox" approach as locations including ingress/egress paths needed to address extreme are acceptable. See calculation L- temperature conditions per 004151, available on ePortal. Note that procedure LOA-FSG-005.
no actions in the Reactor Building are planned for the unit in a severe accident Calculation L-004151, "HCVS after the first hour post-ELAP. FLEX Activities and Phase II Dose Assessment for Unit 1 and For ingress and egress paths outside the 2," Revision O was performed to Reactor Building between 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 7 determine the integrated radiation days, when SAWA is being utilized, a dose due to HCVS operation.
quantitative evaluation of expected dose rates has been performed per HCVS-WP- Temperature and radiological 02 and found the dose rates at conditions should not inhibit deployment locations including operator actions or SAWA ingress/egress paths are acceptable. See equipment and controls needed L-004151. to initiate and operate the HCVS during an ELAP with severe accident conditions.
No follow-up questions.
Phase 2 ISE 01 2 The location of SAWA equipment and The NRC staff reviewed the Closed controls including ingress and egress information provided in the 6-Licensee to evaluate the paths will be the same or similar as FLEX month updates and on the [Staff evaluation to be SAWA [severe accident water and will be bounded by the FLEX ePortal. included in SE Sections addition] equipment and evaluations for temperature and humidity. 4.1.1.4 and 4.2.1.4]
controls, as well as ingress EC 392353, Revision 5, DCS Section 4.1.14 - Environmental
and egress paths for the Conditions and Impacts along expected severe accident with calculations L-004151 shows conditions (temperature, that temperature and radiological humidity, radiation) for the conditions should not inhibit sustained operating period. operator actions or SAWA equipment and controls needed to initiate and operate the HCVS during an ELAP with severe accident conditions.
No follow-up questions.
Phase 2 ISE 01 3 The wetwell vent has been designed to The NRC staff reviewed the Closed meet NEI 13-02 Rev 1 guidance, which information provided in the 6-Licensee to demonstrate that will ensure that it is adequately sized to month updates and on the [Staff evaluation to be containment failure as a result prevent containment overpressure under ePortal. included in SE Sections of overpressure can be severe accident conditions. 4.1 and 4.2]
prevented without a drywell BW ROG-TP-15-008 vent during severe accident The SAWM strategy will ensure that the demonstrates that adding water conditions. wetwell vent remains functional for the to the reactor vessel within 8-period of sustained operation. LaSalle will hours of the onset of the event follow the guidance (flow rate and timing) will limit the peak containment for SAW A/SAWM described in BWROG- drywell temperature significantly TP-15-008 and BWROG-TP-15-011. reducing the possibility of These documents have been posted to containment failure due to the ePortal for NRC staff review. The temperature. Drywell pressure wetwell vent will be opened prior to can be controlled by venting the exceeding the PCPL value of 60 PSIG. suppression chamber through the Therefore, containment over- suppression pool.
pressurization is prevented without the need for a drywell vent. BWROG-TP-011 demonstrates that starting water addition at a high rate of flow and throttling after approximately 4-hours will not increase the suppression pool level to that which could block the suppression chamber HCVS.
As noted under Phase 1, the vent is sized to pass a minimum steam
flow equivalent to 1% rated core power. This is sufficient venting capacity to maintain containment below the lower of PCPL or of design pressure.
No follow-up questions.
Phase 2 ISE 01 4 Reference Plant The NRC staff reviewed the Closed Torus freeboard volume is 525,000 information provided in the 6-Licensee to demonstrate how gallons, SAWA flow is 500 GPM [gallons month updates and on the [Staff evaluation to be the plant is bounded by the per minute] at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> followed by 100 ePortal. included in SE Section reference plant analysis that GPM from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br />, 4.2.1.1]
shows the SAWM strategy is The staff compared the successful in making it unlikely LaSalle parameters from the reference that a drywell vent is needed. Torus freeboard volume is 977,404 plant to those of LaSalle. The gallons, SAWA flow is 500 GPM at 8 staff concurs that it is unlikely the hours followed by 100 GPM from 12 suppression chamber could hours to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br />. become blocked leading to a successful SAWA/SAWM The above parameters for LaSalle strategy. Therefore, it is unlikely compared to the reference plant that a drywell vent would be required determine success of the SAWM strategy to maintain containment integrity.
demonstrate that the reference plant values are bounding. Therefore, the No follow-up questions.
SAWM strategy implemented at LaSalle makes it unlikely that a drywell vent is needed to prevent containment overpressure related failure.
Phase 2 ISE 01 5 LaSalle utilizes handheld radios in the The NRC staff reviewed the Closed talk-around mode to communicate information provided in the 6-Licensee to demonstrate that between the MCR and the operator at the month updates and on the [Staff evaluation to be there is adequate FLEX pump. This communication method ePortal. included in SE Section communication between the is the same as accepted in Order EA 4.1]
main control room (MCR) and 049. These items will be powered and The communication methods are the operator at the FLEX pump remain powered using the same methods the same as accepted in Order during severe accident as evaluated under EA-12-049 for the EA-12-049.
conditions. period of sustained operation, which may be lonQer than identified for EA-12-049. No follow-up questions.
Phase 2 ISE 01 6 For locations outside the Reactor Building The NRC staff reviewed the Closed between 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> and 7 days when SAWA information provided in the 6-
Licensee to demonstrate the is being utilized, a quantitative evaluation month updates and on the [Staff evaluation to be SAWM flow instrumentation of expected dose rates has been ePortal. included in SE Sections qualification for the expected performed per HCVS-WP-02 and found 4.1.1.3 and 4.2.1.3]
environmental conditions. the dose rates at deployment locations EC 392353, DCS Section 4.1.36 including ingress/egress paths are discusses the SAWM flow acceptable (Ref. calculation L-004151, instrumentation qualification. The available on ePortal). The selected NRG staff reviewed the instrument is designed for the expected information and determined that flow rate, temperature and pressure for the accuracy of the flow meter SAWA over the period of sustained and the environmental operation (Ref. 13, DCS 4.1.14 ). Ref. 13 qualifications related to the is available on ePortal. performance of the flow meter meet the intent of Order EA SAWA Flow Instrument 109.
80 to 2300 GPM, Up to 125 °F, Oto 300 No follow-up questions.
PSI Ex~ected SAWA Parameter Qualification Range 100 to 500 GPM, -25 to 101 °F, Oto 250 PSI
ML173548306 *via e-mail OFFICE NRR/DLP/PBEB/PM NRR/DLP/PBMB/LA NRR/DLP/PBEB/BC NRR/DLP/PBEB/PM NAME RAuluck Slent TBrown(KScales for) RAuluck DATE 12/22/2017 12/21/2017 12/22/2017 12/22/2017