ML18190A162

Korea Hydro & Nuclear Power Co, Ltd., Revised Response to RAI 420-8482 for Question 19.03-36 (Rev.2)

ML18190A162
Person / Time
Site:	05200046
Issue date:	07/09/2018
From:	Korea Hydro & Nuclear Power Co, Ltd
To:	Document Control Desk, Office of New Reactors
Shared Package
ML18190A160	List: ML18190A161 ML18190A162
References
MKD/NW-18-0101L
Download: ML18190A162 (16)

Text

19.03-36_Rev. 2 - 1 / 3 KEPCO/KHNP REVISED RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION APR1400 Design Certification Korea Electric Power Corporation / Korea Hydro & Nuclear Power Co., LTD Docket No.52-046 RAI No.: 420-8482 SRP Section: 19.03 - Beyond Design Basis External Event (APR1400)

Application Section: 19.3 Date of RAI Issue: 02/29/2016 Question No. 19.03-36 NRC Commission paper SECY-12-0025 stated that the NRC staff expected new reactor design certification applications to address the Commission-approved Fukushima actions in their applications to the fullest extent practicable. In performing its review of the APR1400 design certification application, the NRC staff followed the guidance for satisfying the Commission directives regarding BDBEE mitigation strategies in Japan Lesson-Learned Project Directorate JLD-ISG-2012-01, Revision 0, which endorsed with clarifications the methodologies described in NEI 12-06, Revision 0. The guidance in JLD-ISG-2012-01 describes one acceptable approach for satisfying the Commission directives regarding BDBEE mitigation strategies (i.e.,

Order EA-12-049). TR APR1400-E-P-NR-14005-P, Rev. 0 provides details regarding mitigating strategies and design enhancements to meet Near-Term Task Force (NTTF) recommendations, NRC orders, and agency guidance related mitigation strategy during Beyond Design Basis External Events (BDBEE).

NEI 12-06, Revision 0 guidance states that unlike 50.54(hh)(2), the intention of this guidance is to have permanent, installed connection points for portable fluid and electrical equipment.

Electrical diversity can be accomplished by providing a primary and alternate method to repower key equipment and instruments utilized in FLEX strategies. At a minimum, the primary connection point should be an installed connection suitable for both the on-site and off-site equipment. The secondary connection point may require reconfiguration (e.g., removal of valve bonnets or breaker) if it can be shown that adequate time is available and adequate resources are reasonably expected to be available to support the reconfiguration. Both the primary and alternate connection points do not need to be available for all applicable hazards, but the location of the connection points should provide reasonable assurance of at least one connection being available. TR, APR1400-E-P-NR-14005-P, Revision 0, Table 5-9, Conformance with NEI 12-06," Rev. 0, states that the appropriate standard mechanical and electrical connections need to be specified and the COL applicants are responsible to establish a means to ensure the necessary resources are available from offsite. Table 5-9 (8 of 20) also states that connections for primary and secondary FLEX pumps, and mobile GTGs, are

19.03-36_Rev. 2 - 2 / 3 KEPCO/KHNP provided on the outside of the exterior wall of the auxiliary building, thereby providing reasonable assurance of the accessibility of personnel and equipment.

1. Provide the COL item that will be used by the COL applicant to ensure the appropriate connection points for the electrical equipment, including voltages and classification.

2. Section 5.1.2.6.1.1 states that the provisions to connect these GTGs are incorporated into the design. Please discuss what the provisions are.

Response - (Rev. 2)

The mobile generators are connected to the Class 1E onsite ac power system train A or B based on each phase of the mitigation strategies for BDBEEs. During phase 1 (or 2), the appropriate electrical connections between local equipment and FLEX equipment will be accomplished to support phase 2 (or 3) according to the FLEX strategies and its associated provisions.

The following provides responses to each corresponding question the staff asked.

1. In order for the COL applicant to ensure the appropriate connection points for the electrical equipment including locations, voltages, and classification, KHNP will add a COL item in the DCD Tier 2, Section 19.3.

2. As described in DCD Tier 2, Subsection 8.3.1.1, the mobile generators supply power to the Class 1E buses through connection boxes, which are watertight type. The connection boxes are installed in the entry and exit of the auxiliary building taking into account the accessibility of the onsite 480V mobile GTG and 4.16 kV mobile generator mobilized from offsite.

With regard to electrical connections, power cables between the connection boxes and incoming circuit breakers of the Class 1E buses are designed as permanent installations and the temporary cables will be connected between the mobile generators and connection boxes according to the APR1400 FLEX strategies.

Further discussion on the design aspects of the mobile generators is provided in the response to RAI 61-7984, Question No. 08.03.01-5 (Reference KHNP submittal MKD/NW-15-0131L, dated September 8, 2015, ML15251A244).

Supplemental Response The number of COL item which was added in the mark-up of previous response has been changed from COL 19.3(10) to COL 19.3(7).

19.03-36_Rev. 2 - 3 / 3 KEPCO/KHNP Impact on DCD The changes that were proposed in the original response to this RAI have been incorporated into Revision 2 of the DCD; therefore, only the pages containing proposed changes as a result of Revisions 1 and 2 of this response are included in the Attachment.

All DCD markups including response to RAI 61-7984 Question 08.03.01-5 Rev.1 related to this change are enclosed in this RAI response.

DCD Tier 1, Figure 2.6.1-1 and DCD Tier 2, Table 1.8-2, Figure 8.1-1, Subsections 8.3.1.1, 8.3.1.1.3.4, Figure 8.3.1-1, and Subsections 8.3.3, 19.3.2.3.1.1, 19.3.2.3.1.3, 19.3.2.3.4, and 19.3.4 will be revised as shown in the Attachment.

Impact on PRA There is no impact on the PRA.

Impact on Technical Specifications There is no impact on the Technical Specifications.

Impact on Technical/Topical/Environmental Reports There is no impact on any Technical, Topical, or Environmental Report.

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (1/13)

APR1400 DCD TIER 1 RAI 420-8482 - Question 19.03-36_Rev.1







TO SWITCHYARD TO SWITCHYARD MAIN XFMR H IPB MAIN GEN. A TO UNIT AUX. XFMR (DIV.II)

STAND-BY AUX. XFMR 2M GEN. CIRCUIT BRK. H X Y EXCITATION 13.8KV 4.16KV XFMR UNIT AUX. XFMR 1M X Y 13.8KV 4.16KV EXCITATION SYSTEM 1A TO AAC SWGR (DIV. II)

CONNECTION CLASS 1E BOX FOR MOBILE CLASS 1E EMERGENCY GTG EMERGENCY DIESEL GEN. 1A DIESEL GEN. 1C 1M TO AAC SWGR (DIV.II)

NO NO NO NO NO NO NO NO NO NO NO PERMANENT NON-CLASS 1E NON-CLASS 1E NON-SAFETY NON-CLASS 1E CLASS 1E CLASS 1E 13.8KV SWGR 13.8KV SWGR 4.16KV SWGR 1M 4.16KV SWGR 4.16KV SWGR 1A 4.16KV SWGR 1C SC PUMP 1 SI PUMP 1 ESW PUMP 1A CS PUMP 1 AF PUMP A SI PUMP 3 CCW PUMP 1A ESW PUMP 2A CHARGING PUMP 1 CCW PUMP 2A RC PUMP 1A, M 2A M CONDENSATE PUMP A M M M COOLING TOWER M ESS CHILLER 02A FW BOOSTER A, C FAN 1A TO 480V LC COOLING TOWER COOLING CW PUMP A, C, E CENTRAL FAN 2A 13800-480V 13800-480V TOWER 4160-480V TGB CCW ADMIN BLDG 4160-480V (DIV.II) 3 4160-480V 4160-480V TR TR TR CHILLER 01, 02 4160-480V PUMP 1 TR FAN GROUP TR TR TR CENTRAL CHILLER WATER PUMP 1 NO 480V 480V 480V 480V LC 480V LC 480V LC 480V LC LC 1A LC 2 LC 1C NO PRESS HTRS BACK-UP MCC GROUP B-1 MCC MCC MCC MCC 1A, 2A, 3A, 4A, 5A 1C, 2C, 3C, 4C MCC CONNECTION BOX FOR 480V MOBILE NON-CLASS 1E GTG NON-CLASS 1E CLASS 1E DIV.I TO SWITCHYARD TO MAIN GENERATOR A H GENERATOR (DIV.I)

STAND-BY AUX. XFMR 2N H X Y 13.8KV UNIT AUX. XFMR 1N 4.16KV X Y 13.8KV 4.16KV 1B TO AAC SWGR CONNECTION CLASS 1E BOX FOR CLASS 1E AAC EMERGENCY MOBILE EMERGENCY GTG 1N TO AAC SWGR GTG DIESEL GEN. 1B DIESEL GEN. 1D NO NO NO NO NO NO NO NO NO NO NO PREMANENT NON-CLASS 1E NON-CLASS 1E NON-SAFETY NON-CLASS 1E CLASS 1E CLASS 1E NON-CLASS 1E 13.8KV SWGR 13.8KV SWGR 4.16KV SWGR 1N 4.16KV SWGR 4.16KV SWGR 1B 4.16KV SWGR 1D 4.16KV AAC SWGR 3N SC PUMP 2 SI PUMP 2 ESW PUMP 1B NO NO NO CS PUMP 2 AF PUMP B SI PUMP 4 CCW PUMP 1B ESW PUMP 2B CONDENSATE ESS CHILLER 01B CCW PUMP 2B PUMP B, C CENTRAL CHILLER 03, 04 CHARGING PUMP 2 ESS CHILLER 02B 1A 1B 1M 1N M RC PUMP M FW BOOSTER B M TGB CCW M COOLING TOWER M COOLING TOWER M CENTRAL CHILLER WATER 1B, 2B PUMP 2 FAN 1B COOLING CW PUMP B, D, F PUMP 2 FAN 2B TO 4.16KV TO 4.16KV TO 4.16KV TO 4.16KV 13800-480V 13800-480V TOWER START-UP FW PUMP 4160-480V 4160-480V 4160-480V 4160-480V TR TR FAN GROUP TR TR TR 3 4160-480V TR SWGR 1A SWGR 1B SWGR 1M SWGR 1N TO 480V LC TR (DIV.I) 480V LC 480V LC 480V LC 480V LC 1B 480V LC 1D 4160-480V 480V LC TR NO MCC MCC 480V AAC LC MCC MCC MCC MCC 1B, 2B, 3B, 4B, 5B 1D, 2D, 3D, 4D CONNECTION BOX FOR PRESS HTRS 480V MOBILE GTG BACK-UP GROUP B-2 MCC NON-CLASS 1E NON-CLASS 1E CLASS 1E NON-CLASS 1E DIV.II 

Figure 2.6.1-1 AC Electrical Power Distribution System 2.6-15 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (2/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 Table 1.8-2 (15 of 39) the 4.16 kV mobile generator and the 480V mobile GTGs Item No. Description COL 8.2(8) The COL applicant is to determine the specific type of the OPDP system which properly address and meet the requirements of B.1. and B.2. of Branch Technical Position (BTP) 8-9, taking into account the site specific design configuration, installation condition, (field) performance testing and qualification status, and operation experiences of the OPDP system.

The COL applicant is also to provide the detailed design of the OPDP system selected for the APR1400 site.

The COL applicant is to perform a field simulation on the site specific design of the offsite power system to ensure that the settings of the OPDP system are adequate and appropriate for the site.

COL 8.2(9) The COL applicant is to describe how testing is performed on the offsite power system components and identify the potential effects that must be considered during testing.

COL 8.2(10) The COL applicant is to provide the required number of immediate access circuits from the transmission network.

COL 8.3(1) The COL applicant is to provide and to design a mobile GTG and its support equipment.

COL 8.3(2) The COL applicant is to provide a bus transfer study of the onsite power system. Based on their the bus transfer study, the COL applicant is also to provide final relay selection and settings for the bus transfer.

COL 8.3(3) The COL applicant is to establish procedures to monitor and maintain EDG reliability during plant operations to verify the selected reliability level target is being achieved as intended in RG 1.155.

COL 8.3(4) The COL applicant is to describe and provide detailed ground grid and lightning protection.

COL 8.3(5) The COL applicant is to conduct periodic inspection and testing of the protection devices for the EPA conductors. All circuit breakers for the EPA conductors shall be inspected and tested in 60 months, low voltage circuit breaker overcurrent protection devices for the EPA conductors shall be inspected and tested once per 18 months for 10 % of each type of circuit breakers, and overcurrent relay for medium voltage circuit breakers for the EPA conductors shall be inspected and tested once per 18 months.

COL 8.3(6) The COL applicant is to provide testing, inspection, and monitoring programs for detecting insulation degradation of underground and inaccessible power cables within the scope of 10 CFR 50.65.

COL 8.3(7) The COL applicant is to establish Administrative Program(s), including application of dedicated cable and raceway management database tool as necessary, which is (are) developed on the basis of the cable and raceway numbering system to efficiently manage cable routing and cable termination and verify that the cable design fulfills the acceptance criteria (i.e., separation, filling criteria, and ampacity).

COL 8.3(8) The COL applicant is to provide the detailed design of the cathodic protection system as applicable to the site conditions.

COL 8.3(9) The COL applicant is to provide protective device coordination.

COL 8.3(10) The COL applicant is to provide the analysis and underlying assumptions used to demonstrate adequacy for insulation coordination of surge and lightning protection.

 

1.8-19 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (3/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 480V mobile GTGs and the 4.16 kV mobile generator.

Table 1.8-2 (38 of 39)

Item No. Description COL 19.3(6) The COL applicant is to confirm and ensure that the raw water tank and flow path to the FLEX equipment (structures, piping, components, and connections) are designed to be robust with respect to applicable hazards (e.g., seismic events, floods, high winds, and associated missiles).G COL 19.3(7) The COL applicant is to provide site-specific details of the electrical connection points (including locations, accessibility, voltage level, and electrical classification) for the mobile GTGs.G COL 19.3(8) The COL applicant is to ensure that all the connections (refer to Table 6-5 in Reference 5) for FLEX strategies located outside the buildings are accessible and protected from all applicable external hazards (e.g., seismic events, floods, high winds, and associated missiles).G COL 19.3(9) The COL applicant is to address site-specific strategies to mitigate BDBEEs as specified in the NRC Order EA-12-049.G COL 19.3(10) The COL applicant is to propose a License Condition to verify the development and implementation of the guidance, strategies, and programs for the mitigation strategies for ensuring core cooling, containment function, and spent fuel pool cooling capabilities during an extended loss of ac power event at an APR1400 nuclear power plant.

COL 19.3(11) The COL applicant is to provide a description of the operational programs that will provide assurance of the functional capability of the pumps, valves, and dynamic restraints used in the mitigation strategies for ensuring core cooling, containment function, and spent fuel pool cooling capabilities during an extended loss of ac power event at an APR1400 nuclear power plant.

COL 19.3(12) The COL applicant is to address SFP level instrumentation maintenance procedure development and perform training as specified in NRC Order EA-12-051.G COL 19.3(13) The COL applicant is to address development of EOPs, SAMGs, and EDMGs that incorporate lessons learned from TEPCO's Fukushima Dai-Ichi nuclear power plant accident as addressed in SECY-12-0025.

COL 19.3(14) The COL applicant is to address enhancement of the offsite communication system as specified in the NRC Request for Information pertaining to NTTF Recommendation 9.3.

COL 19.3(15) The COL applicant is to address staffing for large-scale natural events as specified in the NRC RFI pertaining to NTTF Recommendation 9.3.

COL 19.4(1) The COL applicant is to provide provision and procedure/guidance for implementing SFP strategies, including the minimum pump discharge pressure required to support the minimum flow requirements. All portable equipment is to be stored at least 91.44 m (100 yards) from the auxiliary building. The COL applicant is to specify the external water source(s) to be used.

COL 19.4(2) The COL applicant is to provide fire fighting response strategy.

COL 19.4(3) The COL applicant is to provide procedure/guidance for implementing the IRWST makeup strategy.

COL 19.4(4) The COL applicant is to determine the portable DC power source and connection device to SG pressure and level indication panels.

1.8-42 5HY

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (4/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 SWITCHYARD SWITCHYARD PLANT MAIN XFMR PLANT MAIN GEN IPB TO STAND-BY AUX 1 TO UNIT AUX. XFMR 1N 2 24KV XFMR 2N H

GEN. CIRCUIT BRK. EXCITATION STAND-BY AUX. XFMR 2M XFMR H UNIT AUX. XFMR 1M X Y 13.8KV 4.16KV 24KV EXCITATION SYSTEM X Y 13.8KV 4.16KV CLASS 1E CLASS 1E EMERGENCY EMERGENCY DIESEL GEN. 1A DIESEL GEN. 1C NO NO NO NO NO NO NO NO NON-CLASS 1E NON-CLASS 1E PERMANENT NON-SAFETY NON-CLASS 1E CLASS 1E CLASS 1E 13.8KV SWGR 1M 13.8KV SWGR 2M 4.16KV SWGR 1M 4.16KV SWGR 2M 4.16KV SWGR 1A 4.16KV SWGR 1C NO NO NO 4160-480V XFMR M M M 1M 1A SC PUMP 1 M M M SI PUMP 1 RC PUMP 1A,2A CONDENSATE PUMP A COOLING CENTRAL ADMIN BLDG TO AAC SWGR ESW PUMP 1A CONNECTION CS PUMP 1 TO AAC SWGR TGBCCW FW BOOSTER A,C TOWER FAN CHILLER 1,2 AF PUMP A BOX FOR SI PUMP 3 PUMP 1 (Note 1) (Note 1) (Note 1)

CCW PUMP 1A MOBILE CW PUMP A,C,E GROUP CENTRAL CHILLED WATER 4160-480V PUMP 1 XFMR CONNECTION ESS CHILLER 1A CHARGING PUMP 1 GTG ESW PUMP 2A CCW PUMP 2A ESS CHILLER 2A GENERATOR BOX FOR COOLING TOWER FAN 1A COOLING TOWER FAN 2A 480V MOBILE GTG TO 480V MCC 13800-480V 13800-480V 4160-480V 4160-480V 4160-480V LC 1B 4160-480V XFMR XFMR XFMR XFMR XFMR XFMR 5 PRESS HTRS BACK-UP GROUP B-1 NO DUMMY NO DUMMY NON-CLASS 1E BRK. BRK.

480V LC 480V LC 480V LC 480V LC 480V LC 480V LC 1A 480V LC 2(SWING BUS) 480V LC 1C NO NO NO NO MCC MCC MCC MCC MCC MCC 1A MCC 1C AUX. CHARGING BATT. BATT. M PUMP3 CHARGER CHARGER BATT. BATT. BATT. BATT.

(STAND-BY) (STAND-BY) CHARGER 2A CHARGER 1A CHARGER 2C CHARGER 1C REG. XFMR REG. XFMR (STAND-BY) (STAND-BY)

BATT. 480-120V, 480-120V, REG. XFMR 1A REG. XFMR 1C CHARGER 1 1 480-120V, 1 480-120V, 1 3

TO 125V DC 4 A B CONT. 125V DC 125V DC 125V DC CENTER TO 250V DC BATTERY BATTERY 1A BATTERY 1C CONT. M M M CENTER 125V DC CONT. 125V DC CONT. 125V DC CONT.

CENTER CENTER 1A CENTER 1C A B A A A A M M M M 120V AC 120V AC 120V AC 120V AC DISTR. PNL DISTR. PNL DISTR. PNL DISTR. PNL INVERTER INVERTER INVERTER 1A INVERTER 1C Note TRAIN A TRAIN C

1) Simplified AC Power Distribution System.

Detailed drawing is provided in Figure 8.3.1-1.

NON-CLASS 1E CLASS 1E Figure 8.1-1 Electric Power System Single-Line Diagram (Division I) (1 of 2) 8.1-25 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (5/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 SWITCHYARD GENERATOR 2

TO MAIN IPB GENERATOR 11 H STAND-BY AUX. XFMR 2N H X Y 13.8KV 4.16KV UNIT AUX. XFMR 1N X Y 13.8KV 4.16KV CLASS 1E CLASS 1E EMERGENCY EMERGENCY AAC DIESEL GEN. 1B DIESEL GEN. 1D GTG NO NO NO NO NO NO NO NO NO PERMANENT NON-CLASS 1E NON-CLASS 1E NON-SAFETY NON-CLASS 1E CLASS 1E CLASS 1E NON-CLASS 1E 13.8KV SWGR 1N 13.8KV SWGR 2N 4.16KV SWGR 1N 4.16KV SWGR 2N 4.16KV SWGR 1B 4.16KV SWGR 1D 4.16KV AAC SWGR 3N NO NO NO NO NO 1A 1 1B 1M 1 1N 4160-480V B N M M M 1N M 1B M XFMR M TO 4.16KV SWGR 1B TO 4.16KV SWGR 1M TO 4.16KV SWGR 1N COOLING TO 4.16KV SWGR 1A RC PUMP 1B,2B CONDENSATE PUMP B,C CENTRAL TGBCCW SC PUMP 2 CONNECTION CS PUMP 2 TOWER TO AAC SWGR TO AAC SWGR SI PUMP 2 BOX FOR FW BOOSTER B CHILLER 3,4 PUMP 2 SI PUMP 4 FAN ESW PUMP 1B MOBILE (Note 1) (Note 1) (Note 1)

CW PUMP B,D,F CENTRAL ESW PUMP 2B START-UP FW PUMP GROUP CHILLED WATER AF PUMP B GTG CCW PUMP 2B PUMP 2 CONNECTION CCW PUMP 1B ESS CHILLER 2B BOX FOR ESS CHILLER 1B COOLING TOWER 480V MOBILE CHARGING PUMP 2 FAN 2B GTG COOLING TOWER 13800-480V 13800-480V 4160-480V 4160-480V 4160-480V FAN 1B 4160-480V XFMR XFMR XFMR XFMR XFMR XFMR MCC 4160-480V 4160-480V PRESS HTRS XFMR XFMR BACK-UP NO GROUP B-2 NON-CLASS 1E 480V LC 480V LC 480V LC 480V LC 480V LC 480V LC 1B 480V LC 1D 480V LC NO NO MCC MCC MCC MCC MCC MCC 1B MCC 1D MCC MCC E 5 TO 480V LC 2 TO STAND-BY TO STAND-BY BATT. CHARGER F REG. XFMR REG. XFMR K BATT. CHARGER 480-120V, 1 480-120V, 1 3

REG. XFMR 1B REG. XFMR 1D TO CPB MCC 4 BATT. BATT. 480-120V, 1 CHARGER 2B 480-120V, 1 CHARGER 2D BATT.

E BATT. BATT.

K F (STAND-BY) CHARGER 1B (STAND-BY) CHARGER 1D CHARGER BATT.

BATT. CHARGER BATT.

CHARGER CHARGER 125V DC 125V DC 125V DC C D 125V DC 125V DC BATTERY BATTERY M 250V DC BATTERY BATTERY BATTERY 1D BATTERY M M 1B M F

125V DC CONT. 250V DC CONT. 125V DC CONT. 125V DC CONT. 125V DC CONT.

CENTER CENTER 125V DC CONTROL CENTER CENTER 1B CENTER 1D CENTER C D REG. XFMR REG. XFMR 480-120V, 1 480-120V, 1 REG. XFMR 480-120V, 1 UPS UPS UPS A A A A M M M M 120V AC 120V AC 120V AC 120V AC 120V AC 120V AC 120V AC DISTR. PNL DISTR. PNL DISTR. PNL DISTR. PNL DISTR. PNL DISTR. PNL DISTR. PNL UPS TG UPS INVERTER INVERTER INVERTER 1B INVERTER 1D AAC UPS TRAIN B TRAIN D Note

1) Simplified AC Power Distribution System.

Detailed drawing is provided in Figure 8.3.1-1.

NON-CLASS 1E CLASS 1E NON-CLASS 1E Figure 8.1-1 Electric Power System Single-Line Diagram (Division II) (2 of 2) 8.1-26 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (6/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 8.3 Onsite Power Systems 8.3.1 AC Power Systems 8.3.1.1 Description The onsite ac power system includes standby power sources, distribution systems, and auxiliary supporting systems that are provided to supply power to safety-related equipment or equipment important to safety for all normal operating and accident conditions. There are four Class 1E emergency diesel generators (EDGs) and one non-Class 1E gas turbine generator (GTG). The alternate alternating current (AAC) source is used as a standby power source for the onsite ac power system. The four Class 1E EDGs provide backup power to the Class 1E 4.16 kV buses in the event of a loss of offsite power (LOOP). One Class 1E EDG is dedicated to the respective Class 1E 4.16 kV bus. The non-Class 1E AAC GTG provides backup power to the permanent non-safety (PNS) buses during a LOOP and the dedicated Class 1E 4.16 kV bus during a station blackout (SBO). mobile generator the 4.16 kV mobile generator or 480V mobile GTGs The Class 1E ac power system is supplied power from one 4.16 kV or one of two 480V generator mobile GTGs in case of a beyond-design-basis external event. The 4.16 kV mobile GTG is connected to the 4.16 kV switchgear 1A (or 1B), and the 480V GTG is connected to 480V load center 1A (or 1B). The connection box provided for the connection of a cable between the mobile GTG and the Class 1E bus is watertight. The connection box is installed in the entry and exit of the auxiliary building where the connection boxes are their readily accessible to the mobile GTG. The COL applicant is to provide and to design a mobile GTG and its support equipment (COL 8.3(1)). In addition, Class 1E switchgear rooms are also designed with watertight exterior barriers and doors to prevent the inflow of floodwater.

the 4.16 kV mobile generator and the 480V mobile GTGs The mitigation strategies for beyond-design-basis external events, which involve operation of the mobile generators, are described in Section 19.3 of Chapter 19.

The onsite power system consists of the Class 1E power system and the non-Class 1E power system. The onsite power system is normally powered from two unit auxiliary transformers (UATs). If the normal preferred power source from UATs is unavailable, all Class 1E and non-Class 1E buses are automatically transferred to the alternate preferred power source from standby auxiliary transformers (SATs) by the fast and residual transfer scheme. For the automatic fast transfer, the synchro-check relay for each bus is used to supervise the voltage difference between the switchgear bus and upstream of the alternate 8.3-1 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (7/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1

f. Phase (negative phase sequence) unbalance

g. Diesel generator fail to start

h. Running unloaded

i. Cranking

j. Subsystem trouble (ac generator, fuel oil system, lube oil system, cooling water system, starting system, excitation loss, and miscellaneous).

8.3.1.1.3.4 Interlocks Each Class 1E 4.16 kV bus can be powered by either of the two offsite power sources or the Class 1E EDG of each train. In addition, each of train A and train B Class 1E 4.16 kV bus generator can also be powered by non-Class 1E AAC GTG or 4.16 kV mobile GTG.

a. The interlock circuits of incoming breakers prevent parallel operation between normal and alternate preferred power supplies during manual transfer between UAT and SAT.

b. The EDG is permitted to operate in parallel with an offsite power source after synchronizing both sources during periodic testing.

c. The incoming circuit breakers are manually closed after synchronizing the offsite power sources with the Class 1E 4.16 kV bus when the preferred power supply is restored from a LOOP or SBO event.

d. The electrical interlocks of the circuit breaker are provided to prevent the automatic closing of an EDG breaker onto an energized or faulted bus.

8.3.1.1.3.5 Permissive The EDG operational mode selection is provided at the EDG local control panel through a LOCAL/REMOTE selector switch and a NORMAL/MAINTENANCE selector switch.

Emergency start and emergency trip functions are not blocked by LOCAL mode selection.

Selection of the NORMAL mode also enables the selection of REMOTE/LOCAL mode switch. Selection of the MAINTENANCE mode blocks all automatic or manual 8.3-13 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (8/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 TO UAT 01M TO SAT 02M TO AAC SWGR 03N TO UAT 01M TO SAT 02M TO UAT 01N TO SAT 02N TO AAC SWGR 03N TO UAT 01N TO SAT 02N 1A 1B A A A A C C C C B B B B MFR MFR MFR MFR NO NEUTRAL NO NO NO NEUTRAL NO NO NEUTRAL NO NO NO NEUTRAL NO GRND 27 GRND GRND GRND CLASS 1E 27 CLASS 1E CLASS 1E 27 CLASS 1E 27 XFMR XFMR XFMR XFMR 4.16KV 4.16KV 4.16KV 4.16KV SWGR MFR MFR MFR SWGR MFR MFR SWGR MFR MFR MFR SWGR MFR MFR SW01A SW01C SW01B SW01D MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR MFR NO NO M M M M M M M M M M M M M M M M M M M M M M M M M M M M ESS ESW PUMP CCW PUMP CNMT SPRAY SC PUMP 1 AF PUMP A CHARGING ESS SI PUMP 1 ESW PUMP ESS ESS COOLING SC PUMP 2 AF PUMP B CHARGING COOLING ESW CCW SI PUMP 2 SI PUMP 4 SI PUMP TO CONNECTION BOX TO CONNECTION BOX CNMT COOLING COOLING TOWER TOWER CCW ESW CCW PUMP 1 CHILLER 1A 2A 2A CHILLER 2A PUMP 2 SPRAY TOWER PUMP 1A TOWER PUMP 1A 3 PUMP 2 1B CHILLER 1B CHILLER 2B FAN 1A FAN 2A PUMP 1B PUMP 2B PUMP 2B PUMP 1 FAN 1B FAN 2B A TO 480V A A A A A FOR MOBILE GTG FOR MOBILE GTG 4160-480V LC01B 4160-480V 4160-480V 4160-480V 4160-480V 4160-480V C B XFMR 01A C B XFMR 13M C B XFMR 01C C B XFMR 01B C B XFMR13N C B XFMR 01D A A A A A A C C B C C C B C B NO DUMMY B B B BRK.

(MANUAL) 480V LC 480V LC02 480V LC 480V LC 480V LC LC01A (SWING BUS) LC01C LC01B LC01D NO NO MCC MCC MCC MCC MC01A,02A PRESS HTRS MC01C,02C MC01B,02B PRESS HTRS MC01D,02D 03A,04A,05A BACK-UP 03C,04C 03B,04B,05B BACK-UP 03D,04D GROUP B-1 GROUP B-2 TO CONNECTION TO 480V LC02 TO CONNECTION BOX FOR MOBILE BOX FOR MOBILE GTG GTG TRAIN A NON-CLASS 1E TRAIN C TRAIN B NON-CLASS 1E TRAIN D GENERATOR DIVISION II DIVISION I Class 1E 4.16 kV AC Power System Figure 8.3.1-1 Onsite AC Electrical Power System (3 of 3) 8.3-114 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (9/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 8.3.2.3.7 Grounding The dc power system is designed to be an ungrounded system, which enhances the system reliability and service continuity because a single ground has no adverse effect on the system operation. Each train has a ground detector to isolate and monitor the fault area.

The ground detector has an alarm in the MCR to monitor constant grounding and recording.

The ground detector has high sensitivity.

the 4.16 kV mobile generator and the 480V mobile GTGs 8.3.3 Combined License Information COL 8.3(1) The COL applicant is to provide and to design a mobile GTG and its their support equipment.

COL 8.3(2) The COL applicant is to provide a bus transfer study of the onsite power system. Based on the bus transfer study, the COL applicant is also to provide final relay selection and settings for the bus transfer.

COL 8.3(3) The COL applicant is to establish procedures to monitor and maintain EDG reliability during plant operations to verify the selected reliability level target is being achieved as intended in RG 1.155.

COL 8.3(4) The COL applicant is to describe and provide detailed ground grid and lightning protection.

COL 8.3(5) The COL applicant is to conduct periodic inspection and testing of the protection devices for the EPA conductors. All circuit breakers for the EPA conductors shall be inspected and tested in 60 months, low voltage circuit breaker overcurrent protection devices for the EPA conductors shall be inspected and tested once per 18 months for 10 % of each type of circuit breakers, and overcurrent relay for medium voltage circuit breakers for the EPA conductors shall be inspected and tested once per 18 months.

COL 8.3(6) The COL applicant is to provide testing, inspection, and monitoring programs for detecting insulation degradation of underground and inaccessible power cables within the scope of 10 CFR 50.65.

COL 8.3(7) The COL applicant is to establish Administrative Program(s), including application of dedicated cable and raceway management database tool as 8.3-58 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (10/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 RAI 420-8482 - Question 19.03-36_Rev.2 Two primary high-head FLEX pumps and three secondary FLEX pumps are provided to meet the N+1 requirement.

Additionally, as RCS cooldown continues and RCS pressure decreases to the designed setpoint of safety injection tank (SIT) injection, the SIT automatically discharges 4,000 ppm borated water into the RCS for boration and inventory makeup.

generator Phase 3: after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> In Phase 3, offsite resources, including a 4.16 kV mobile GTG, fuel, and cooling water can be assumed to be available for long-term coping with the BDBEE. The 4.16 kV mobile GTG will be used to restore Train A or B of the 4.16 kV Class 1E power system. The generator plant will be brought to cold shutdown, using the shutdown cooling system (SCS), if the ultimate heat sink (UHS) is available after 4.16 kV Class 1E power is restored. If not, the plant is maintained at the same safe shutdown state as in Phase 2.

In this phase, the primary and secondary makeup water sources and fuel oil for the mobile GTGs will be refilled from offsite resources.

19.3.2.3.1.2 Low-Power Operation with SGs available Strategy for Mode 1 through Mode 3 4.16 kV mobile generator and the 480V mobile GTG The NCC analysis result for the full-power FLEX strategy is still valid for operation in modes 1 through 3,i.e., lower-power operation, startup, and hot standby conditions, because it covers various states of the plant,including full-power operation through hot shutdown condition. Therefore, the same FLEX strategy as in thefull-power operation can be also applied to the modes 1 through 3 operations.

Strategy for Mode 4 and Mode 5 with SGs Available In these operation modes, the SCS normally maintains the RCS between 176.67 °C (350 °F)

(hot shutdown) and 54.44 °C (130 °F) (cold shutdown), while the SGs are still available.

If the event an ELAP concurrentwith LUHS occurs during these operation modes, the RCS is heated up and pressurized due to the loss of the SCS.

If the RCS temperature is initially below the maximum RCS temperature requiring low-temperatureoverpressurization protection (LTOP), i.e., 136.11 °C (277 °F), the RCS pressure can be maintained below theLTOP protection limiting pressure of 43.94 kg/cm2A 19.3-6 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (11/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 RAI 420-8482 - Question 19.03-36_Rev.2 head FLEX pump must be aligned to take suction from the acceptable coolant source and deliver the coolant to the vessel. A mobile GTG is prepared to connect to Train A or Train B 480 V Class 1E ac power system to supply power to Class 1E battery. Two primary low-head FLEX pumps are provided to meet the N+1 requirement. The COL applicant is generator to address the details of storage location for FLEX equipment (COL 19.3(4)). In Phase 3, the 4.16 kV mobile GTG, fuel, and cooling water are available from offsite for long-term coping for the event. The 4.16 kV mobile GTG is used to restore Train A or Train B of generator 4.16 kV Class 1E power system. If the SCS is operable when the 4.16 kV Class 1E power is restored, the plant is cooled down to and maintained at cold shutdown by resuming the SCS operation. If not, the plant is maintained at the same safe shutdown state as in Phase 2, using the primary FLEX pump for RCS inventory makeup. In this phase, the primary and secondary makeup water sources and fuel oil for the mobile GTGs will be refilled from offsite resources. The COL applicant is to develop shutdown risk processes and procedures, and verify ability to deploy FLEX equipment to provide core cooling in shutdown operation with SGs not available (COL 19.3(17)).

4.16 kV mobile generator and the 480V mobile GTG Indication of Core Coverage The operator can monitor the RCS level in MCR via flat panel display (FPD) from qualified indication and alarm system - P (QIAS-P). Coolant level during the reduced inventory operations is measured by the permanent refueling water level indication system (PRWLIS), the local refueling water level indication system (LRWLIS), and the ultrasonic level measurement system (ULMS). The PRWLIS consists of the wide range (WR) level instrument and the narrow range (NR) level instrument. Each of two trains provides the means of monitoring water level of each RCS loop to the MCR during reduced RCS inventory operations. The PRWLIS (WR) indicates coolant level between 10% level of the pressurizer and the bottom of the hot leg. It provides level indication to the MCR without alarm. The PRWLIS (NR) indicates coolant level between the top of the hot leg and 2 in above the bottom of the hot leg. It provides level indication and Low, Low-Low and High alarms to the MCR. The LRWLIS (Sight Glasses) indicates coolant level between 3 ft below the reactor vessel flange and the bottom of the hot leg. The LRWLIS provide level indication and Low and Low-Low alarms to the MCR. The ULMS is installed temporarily on both hot legs to monitor coolant level of hot leg during mid-loop operation. The ULMS provides indication, audible and visible alarms which consist of High, Low, and Low-Low alarms, and record functions to the MCR. Core exit temperature (CET) also can be 19.3-8 Rev. 2

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (12/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 The detailed design of the raw water tank related with site specific data is the responsibility of the COL applicant. The COL applicant is to confirm, satisfy, or fulfill the specific design functional requirements of raw water tank including the associated instrument, capacity, location, flow path to on-site, the valve pit connected to FLEX equipment, and any other design features as described in DCD Section 19.3 in support of BDBEE mitigation strategies (COL 19.3(5)). The COL applicant is to confirm and ensure that the raw water tank and flow path to the FLEX equipment (structures, piping, components, and connections) are designed to be robust with respect to applicable hazards (e.g., seismic events, floods, high winds, and associated missiles) (COL 19.3(6)).

480V mobile GTGs and the 4.16 kV mobile generator The COL applicant is to provide site-specific details of the electrical connection points (including locations, accessibility, voltage level, and electrical classification) for the mobile GTGs (COL 19.3 (7)).

The COL applicant is to ensure that all the connections (refer to Table 6-5 in Reference 5) for FLEX strategies located outside the buildings are accessible and protected from all applicable external hazards (e.g., seismic events, floods, high winds, and associatedmissiles)

(COL 19.3 (8)).

Also, the COL applicant is to address site-specific strategies to mitigate BDBEEs as specified in NRC Order EA-12-049 (COL 19.3(9)), including but not limited to the following:

a. Evaluation of site-specific external hazards

b. Determination and protection of portable equipment including final design head for FLEX pumps

c. Providing means for acquisition, staging, and installation of equipment

d. Establishing means for maintaining and testing of portable equipment

e. Establishing procedures and guidance on mitigation of BDBEEs

f. Establishing training of personnel to the developed strategies and procedures The COL applicant is to propose a License Condition to verify the development and implementation of the guidance, strategies, and programs for the mitigation strategies for ensuring core cooling, containment function, and spent fuel pool cooling capabilities during 19.3-13 5HY

RAI 420-8482 - Question 19.03-36_Rev.2 Attachment (13/13)

APR1400 DCD TIER 2 RAI 420-8482 - Question 19.03-36_Rev.1 COL 19.3(3) The COL applicant is to develop the details for offsite resources.

COL 19.3(4) The COL applicant is to address the details of selecting suitable storage locations for FLEX equipment that provide reasonable protection during specific external events as provided in NEI 12-06 guidance Sections 5 through 9, and the details of the guidance for storage of FLEX equipment provided in the Technical Report (Reference 5) Section 6.2.9.

COL 19.3(5) The COL applicant is to confirm, satisfy, or fulfill the specific design functional requirements of raw water tank including the associated instrument, capacity, location, flow path to on-site, the valve pit connected to FLEX equipment, and any other design features as described in DCD Section 19.3 in support of BDBEE mitigation strategies.

COL 19.3(6) The COL applicant is to confirm and ensure that the raw water tank and flow path to the FLEX equipment (structures, piping, components, and connections) are designed to be robust with respect to applicable hazards (e.g., seismic events, floods, high winds, and associated missiles).

480V mobile GTGs and the 4.16 kV mobile generator.

COL 19.3(7) The COL applicant is to provide site-specific details of the electrical connection points (including locations, accessibility voltage level, and electrical classification) for the mobile GTGs.

COL 19.3(8) The COL applicant is to ensure that all the connections (refer to Table 6-5 in Reference 5) for FLEX strategies located outside the buildings are accessible and protected from all applicable external hazards (e.g., seismic events, floods, high winds, and associated missiles).

COL 19.3(9) The COL applicant is to address site-specific strategies to mitigate BDBEEs as specified in the NRC Order EA-12-049.

COL 19.3(10) The COL applicant is to propose a License Condition to verify the development and implementation of the guidance, strategies, and programs for the mitigation strategies for ensuring core cooling, containment function and spent fuel pool cooling capabilities during an extended loss of ac power event at an APR1400 nuclear power plant.

19.3-17 5HY