ML12160A351

Submittal of Additional Information Requested to NUREG-0847 Supplemental Safety Evaluation Report Related to Appendix Hh Open Item 26 - Diesel Generator

ML12160A351
Person / Time
Site:	Watts Bar
Issue date:	06/07/2012
From:	Hruby R Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME0853
Download: ML12160A351 (36)

Text

Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 June 7, 2012 10 CFR 50.34(b)

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant Unit 2 Docket No. 50-391

Subject:

Watts Bar Nuclear Plant (WBN) Unit 2 - NUREG-0847 Supplemental Safety Evaluation Report (SSER) Related to the Operation of Watts Bar Nuclear Plant, Unit 2, Appendix HH Open Item 26 - Diesel Generator Response (TAC No. ME0853)

References:

1. NRC letter to TVA dated November 18, 2011, "Watts Bar Nuclear Plant, Unit 2 - Request for Additional Information Regarding Supplemental Safety Evaluation Report Open Item 26"

2. TVA letter to NRC dated April 6, 2011, "Watts Bar Nuclear Plant (WBN) Unit 2 - Safety Evaluation Report Supplement 22 (SSER22) -

Response to NRC Required Action Items" The purpose of this letter is to provide the additional information requested by the NRC in Reference 1 related to Emergency Diesel Generator (EDG) response and performance during loss of offsite power events, electrical system response to gradual submergence of equipment after a loss of coolant accident, and specific impacts of a loss of ventilation during station blackout conditions.

The requested information is provided in the enclosure and associated attachments and shows that the plant design conforms to the applicable regulatory requirements.

There are no new regulatory commitments contained in this letter. If you have any questions, please contact Gordon Arent at (423) 365-2004.

U.S. Nuclear Regulatory Commission Page 2 June 7, 2012 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 7th day of June, 2012.

Respectfully, Raymond A. Hruby, Jr.

General Manager, Technical Services Watts Bar Unit 2

Enclosure:

Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 cc (Enclosure):

U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Resident Inspector Unit 2 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 NRC Question:

The licensee has attempted to demonstrate design margin based on 'hot and cold' engine capability and 'step load' capability. These ratings are not normally cited for DGs in nuclear power plant applications. The Final Safety Analysis Report (FSAR) states that the DG rating is 4400 kW continuous and 4840 kW for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> out of 24 at a power factor of 0. 8.

1 Based on the above information, the staff has the following questions:

a)

Explain the variations in the worst-case loading provided in different responses and provide a summary of current calculations depicting DG loading, including procedurally required loads that may be manually connected.

TVA Response:

Based on discussion with the NRC Region II staff, Calculation EDQ 00099920080014, "Diesel Generator Loading Analysis" (Reference 1), has been rewritten to improve readability. Because of the ongoing plant modifications and NRC inspections, EDG loading is being constantly adjusted to account for the modifications and NRC comments. This explains the variations in the worst-case loading provided in different responses. Excerpts from Reference 1 are attached as Attachment 1. The loading computations are split in two sections:

The first section delineates the load carryingq capability (steady-state running load) and margin available for the worst case EDG loading for two separate events. As stated in the Final Safety Analysis Report (FSAR), load carrying capability is based on a 2-hour rating of 4840 kW from 0 to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and on a continuous rating of 4400 kW from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to the end. Table 1, provided in, depicts worst case EDG loading with available margin when serving loads during a loss of offsite power (LOOP) concurrent with a loss of coolant accident (LOCA). Table 2 depicts worst case EDG loading with available margin when serving loads during a LOOP only.

The second section delineates the motor startingq capability of each EDG for the same two separate events. Table 1 depicts the maximum transient load carrying capability when serving loads during a LOOP concurrent with a LOCA. As stated in the FSAR, this transient load carrying capability is based on a rating of 4785 kW for the first 3 minutes (0-180 seconds) and on 5073 kW from 180 seconds to the end. Table 2 depicts the maximum transient loading when serving loads during a LOOP only.

To demonstrate compliance with Regulatory Guide 1.9 (i.e., voltage does not decrease to less than 75% of nominal), the TVA design approach is not to allow the maximum step load increase in kVA to exceed the manufacturer's guaranteed performance characteristics. Thus the "Step Load" capability is defined as the maximum transient step load increase in kVA that the generator/exciter can accept without exceeding the minimum voltage limit prescribed by Regulatory Guide 1.9. This generator "Step Load" capability was determined to be 8000 kVA, and TVA has demonstrated that the starting kVA of any motor will not exceed 8000 kVA.

In addition, Attachment 2 provides EDG loading with one unit in LOOP plus LOCA and the second unit in LOOP only. The first set of tables in Attachment 2 provides EDG steady state running loads in the above scenario. The second set of tables in Attachment 2 provides EDG E-1

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 maximum transient loads showing both real power as well as apparent power in the above scenario. The values in these Tables are extracted from Reference 1.

NRC Question:

b)

Provide verification or test documents from manufacturer or Appendix B qualified supplier of DG engine and DG generator certifying the 'hot, cold and step load' capabilities.

TVA Response:

The document that established the "Cold" Engine (first 3 minutes [180 seconds] of load sequence) and "Hot" Engine (fully turbocharged, 180 seconds to the end) capability was provided to the NRC as Attachment 1 to TVA letter to the NRC dated December 6, 2010. For staff's convenience the document is attached as Attachment 3. This document established the maximum kW capability of the WBN DGs for starting motors in incremental steps during a design basis accident load sequence. This document concluded that WBN DG maximum kW capability for motor starting in the site service environment (intake air temperature less than 1150 F and elevation less than 800 feet) is:

"Cold" Engine (first 3 minutes of load sequence):

4785 kW "Hot" Engine (fully turbocharged):

5073 kW This document was reviewed and concurred by MKW Power Systems, Inc., the Appendix B qualified supplier of DG engine and DG generator for WBN, as delineated on page 1 of.

NRC Question:

2.

In Table 8.3-14 of FSAR Amendment 106, TVA listed the major electrical equipment that could become submerged following a loss-of-coolant accident (LOCA). The listed equipment is either automatically de-energized or is not required to function after a LOCA. In Sections 8A and 8B, TVA summarized the analysis of submerged (post-LOCA) electrical equipment powered from the auxiliary power system and from the instrumentation and control power system. The analysis concluded that submerged electrical equipment will not degrade the 6.9-kV or 480-V Class 1E instrumentation and control power systems. Identify the equipment and the related power source(s) and explain the consequences of gradual submergence of AC and DC powered equipment that is not qualified or not required post accident but may be energized and results in simultaneous high impedance faults on the electrical system.

TVA Response:

During a post LOCA and borated containment spray condition, some equipment inside the primary containment will be submerged or affected by the containment spray. This condition has the potential to produce multiple failures on the Class 1E 6.9 kV, 480 VAC, 120 VAC, and 125 VDC power systems. TVA evaluated the effect of this condition on the following power sources:

E-2

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 (Note: TVA assumed that if the equipment was located below the flood level, it was energized and was therefore affected by submergence. Therefore, the consequences of gradual submergence of AC and DC powered equipment that was not qualified or not required post accident but may be energized and results in simultaneous high impedance faults on the electrical system was bounded in the WVA analysis. TVA analysis further assumes that the protective device feeding the submerged equipment was loaded to its trip setting which was conservative.)

120 VAC Vital Instrument Power Boards 2-1, 2-11, 2-111 and 2-IV 125 VDC Vital Battery Boards III and IV 120 VAC Hydrogen Mitigation System Panels 2-DPL-268-1-A and 2-DPL-268-2-B 6.9 kV Shutdown Boards 2A-A and 2B-B 480 V Shutdown Boards 2A1-A, 2A2-A, 2B1-B and 2B2-B 480 V Reactor Vent Boards 2A-A and 2B-B 480 V Reactor MOV Boards 2A1-A, 2A2-A, 2B1-B and 2B2-B This evaluation was documented in the TVA submergence calculation for Unit 2 (Reference 2),

excerpt provided in Attachment 4. The equipment fed from each of the above power sources was identified in this evaluation. A determination was made if the equipment was going to be energized and if it was going to be submerged as a result of the event. The evaluation concluded the following:

The additional loading on the 120 VAC vital Class 1E power system due to the submerged equipment does not cause any secondary protective devices to trip nor does it overload the power supply (inverters).

The additional loading on the 125 VDC Class 1E power system due to the submerged equipment does not cause any secondary protective devices to trip nor does it adversely affect the battery sizing. The available voltage at the battery terminals is more than the minimum required voltage.

The loading on the 120 VAC Hydrogen Mitigation System Panels due to the submerged equipment does not cause any secondary protective devices to trip nor does it overload the transformer.

The additional loading on the 6.9 kV and 480 VAC Class 1 E power system due to the submerged equipment does not cause any secondary protective devices to trip nor does it overload the power transformers.

There is no adverse affect on the Class 1 E power systems due to containment spray on the shutdown and non safe shutdown components located inside the containment.

NRC Question:

3.

To demonstrate compliance with station blackout (SBO) rule, TVA performed a steady-state heat-up analyses in accordance with NUMARC 87-00 guidelines to determine the effects of loss of ventilation in main control room complex, turbine-driven auxiliary feedwater pump room, north and south main steam valve rooms, 125V vital battery rooms, 125 vital battery board rooms, cable spreading room, pipe chase, 480 V board rooms, and 6.9 kV and 480 V shutdown board room. From E-3

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 these analyses, provide a detailed list of equipment that is subjected to temperature above the design temperature for normal operation and the results of assessment performed for the equipment to show its continued operability during an SBO event.

TVA Response:

Table A below provides normal operating temperature, maximum abnormal operating temperature and calculated SBO temperature that were calculated using the NUMARC 87-00 guidelines for each of the rooms listed in the RAI (Reference 3). TVA defines the "maximum abnormal operating temperature" as the environmental service conditions which result from outside temperature excursions. This condition can exist for up to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> per excursion for non-reactor building spaces.

For the four rooms, North Main Steam valve room, South Main Steam valve room, Turbine-driven auxiliary feed pump room, and pipe chase, where the calculated SBO temperatures are higher than abnormal operating temperatures, a list of equipment in the rooms that are affected is provided. In addition, the associated assessment for each room is provided in the remarks column of the table.

References:

1. TVA Calculation EDQ00099920080014, "Diesel Generator Loading Analysis"

2. TVA Calculation EDQ00299920080020, "Submergence Calculation - Unit 2"

3. TVA Calculation EPM-MA-041592, "Station Black-out Coping Evaluation"

4. TVA Drawing Series 47E235, "Environmental Data Drawing"

5. TVA Calculation GENSTP3-001, "Upper Boundary Temperature for Mild Environments Related to Environmental Qualification of Electrical Equipment"

6. TVA Calculation EDN002999201110004, "Material Aging Calculation for Auxiliary Feedwater Level Control Valves in the South Steam Valve Rooms (729-AO1 & 729-Al1) for Station Blackout (SBO) Conditions" List of Attachments:

1. Excerpts from calculation EDQ00099920080014, Rev. 15

2. EDG Loading Tables depicting EDG loads with one unit in LOOP+LOCA and the second unit in LOOP

3. EDG Motor Starting Capability

4. Excerpt from Unit 2 Submergence Evaluation E-4

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 Table A - Response to RAI Item # 3 Effects of Loss of Ventilation during SBO Normal Maximum Calculated Equipment Operating Abnormal required to be Index Room Temperature Operating Temperature operational Remark Index(Roe Temperature (during SBO

(°F)

(OF)

(°F) condition.

Panels powered from one of the 8 Main Control Room Complex temperatures are Main Control Vital Inverter not above the abnormal operating temperatures Room Complex 80 104 104 Boards and all as provided on Environmental Data Drawing electrical 47E235-16 (Reference 4) equipment in TSC Reference 3, Appendix G, Page 63 is energized.

Note that the average temperature for the room Turbine Driven TDAFWP Room is 116.4 OF and maximum temperature of Auxiliary 1Exhaust Fan DC 127.7 0F at the end of four hours. Per TVA Feedwater 104 110 127.7 fot fan Calculation GENSTP3-001 (Reference 5),

Room 2-FAN-030-0214 motors in a mild environment are capable of operating for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at 140 OF.

Reference 3, Page 25 North Main There is no equipment in the North Main Steam Steam Valve 135 140 160.8 NONE Valve that is required to operate during SBO.

Room Reference 3, Page 25 TVA Calculation EDN00299920110004 (Reference 6) was performed to evaluate accident degradation equivalency based on a steady state temperature of 200 OF for the four South Main TDAFWP LCVs hour duration of the SBO event. The calculation Steam Valve 140 140 177.9 2-LCV-30-174-B & concluded that the life of safety-related age-Room 2-LCV-30-175-A degradable materials in AFW LCVs in the South Main Steam Valve Room is not significantly impacted by operation for four hours at 200 OF during a SBO event.

I Reference 3, Page 25 E-5

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 Table A - Response to RAI Item # 3 Effects of Loss of Ventilation during SBO Normal Maximum Calculated Equipment Operating Abnormal SBO required to be Temperature Operating Temperature operational Remark (OF)

Temperature (OF) during SBO

(°F)

(OF) condition.

The Station Battery & Battery Board Room Vital 125 VDC Battery, Battery temperatures are not above the maximum Station Battery &

Output Cable, abnormal temperature as provided on 4

Battery Board 85 104 104 Individual Battery Environmental Data Drawing 47E235-3. Also Rooms (Rooms I, Board, and Vital note that the battery rooms can withstand 120 II, Ill, IV)

Instrument Panel.

OF for the period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Reference 3, Appendix G, Page 81 Adjacent room temperatures are higher during normal operation but lower during SBO; 5

Room 95 104 103 NONE therefore, the transmission load removes heat out of the room during a SBO condition Reference 3, Appendix G, Page 76 The pipe chase temperature will gradually rise during an SBO. Hence, it is feasible that this valve could be manually closed, if necessary, by Containment brief excursion into the pipe chase even if the 6

Pipe Chase 104 110 121.9 Isolation Valve temperature is about 122 OF. This would not be 2-FCV-62-63 required unless core damage was imminent and core uncovery is not expected during the 4-hour SBO event.

Reference 3, Page 25 E-6

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 Table A - Response to RAI Item # 3 Effects of Loss of Ventilation during SBO Normal Maximum Calculated Equipment Operating Abnormal SBO required to be Index Room Temperature Operating Temperature operational Remark Tmru Temperature Tmru during SBO

(°F)

(OF)

(0F) condition.

The 480V Board Room temperatures are not above maximum abnormal temperatures as 7 Rooms 83 104 104 Inverters.

provided on Environmental Data Drawing 47E235-3.

Reference 3, Appendix G, Page 69 & 70.

Auxiliary The 6.9 kV & 480V Shutdown Board Room 6.9 KV & 480 V compary temperatures are not above maximum abnormal 8

Shutdown Board 87 104 104 compartments temperatures as provided on Environmental Rooms which an Data Drawing 47E235-7.

meters and relays.

Reference 3 Appendix G, Page 73 E-7

ENCLOSURE Response to Action item 26 From Appendix HH of NUREG-0847, Supplement 22 Excerpts from calculation EDQ00099920080014, Rev. 16 E-8

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 14 SHEET 17 5.0 COMPUTATIONS AND ANALYSES 5.1 The Electrical Transient Analysis Program (ETAP) Version 5.5.6N (Reference 3.15) is used to perform the DG loading analysis. The data for the connected load and their operating time is contained in ETAP database. The Motor Dynamic Starting Analysis tool in ETAP is used to analyze the loading (kW and kVA) on each of the Emergency Diesel Generators. The DGs are modeled as infinite swing sources that will adjust their MVAR output to maintain constant voltage. The electrical loading on each WBN Diesel Generator (DG) is calculated and compared to the DG ratings. provides a detailed set of instructions on how the case studies are performed to determine the loading (kW and kVA) on each of the WBN Emergency Diesel Generators using the ETAP software. In the ETAP analysis motors are modeled to start dynamically in accordance with the ETAP motor model, static loads just turn on and MOVs load is applied for the duration of their stroke time in accordance with the ETAP MOV model.

5.2 Automatically & Manually Sequenced Loads Automatically sequenced loads are added based on the starting times stated in Appendix A.

Manually operated loads are administratively controlled in accordance with abnormal operating instruction AOI-35 and will not be automatically sequenced onto or off the Diesel Generators. The operator has the responsibility to maintain the loading within the Diesel Generator ratings. The only required manual load additions are the hydrogen mitigation system and hydrogen recombiners (for Unit 1 only; Unit 2 Hydrogen Recombiners have been deleted by EDCR 52329, Ref. 3.20) which are added prior to (or after) two hours. These loads have been included with the DGs loading analyses, starting 30 minutes after t = 0, which is conservative. The manual loads are as follows (refer ETAP database for load):

Load ID UNID Rating (kW)

Description 203-9E 1-DXF-268-1-A 35.75 Perm Hydrogen Mitigation Sys 1A-A 205-12C 1-DXF-268-2-B 35.75 Perm Hydrogen Mitigation Sys 1B-B 243-2D 1-HTR-83-1-A 75 Hydrogen Elec Recombiner 1A-A 244-2D 1-HTR-83-2-B 75 Hydrogen Elec Recombiner 1B-B 207-9E 2-DXF-268-1 -A 35.75 Perm Hydrogen Mitigation Sys 2A-A 209-12C 2-DXF-268-2-B 30 Perm Hydrogen Mitigation Sys 2B-B 5.3 Random Loads The DGs and associated largest random loads are listed as follows:

DG Load ID UNID Rating Description (HP) 1A-A 127-2C 0-MTR-31-80/2-A

• 177 Cont Room A/C A-A Cprsr 127-4D 0-MTR-26-1-A **

200 Station Fire Pump lA-A (LOOP) 128-9D 0-MTR-31-45-A 75 Shdn Bd Room AHU A-A 203-11D 0-MTR-31-12-A 60 Cont Room AHU A-A 1B-B 131-3C 0-MTR-31-49/2-B

• 237 Shdn Bd Room A/C B-B Cprsr 131-4D 0-MTR-26-4-B **

200 Station Fire Pump 1B-B (LOOP) 132-9D 0-MTR-31-55-B 75 Shdn Bd Room AHU C-B 205-IID 0-MTR-31-11-B 60 Cont Room AHU B-B

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 14 SHEET 18 2A-A 135-2C 0-MTR-31-128/2-A

• 250 Elec Bd Room A/C A-A Cprsr 135-4D 0-MTR-26-9-A **

200 Station Fire Pump 2A-A (LOOP) 136-8D 0-MTR-31-44-A 75 480V Shutdown BD Rm AHU B-A 2B-B 139-2B 0-MTR-31-129/2-B

• 250 Elec Bd Room A/C B-B Cprsr 139-4D 0-MTR-26-11-B **

200 Station Fire Pump 2B-B (LOOP) 140-9D 0-MTR-31-61-B 75 480V Shutdown Bd Rm AHU D-B Control Room, Shdn Bd Room and Elec Bd Rooms A/C Compressors have a time delay of 6 minutes (360s) to prevent successive re-start after loss of power (Ref. 3.18 & 3.19).

• • Fire Pump starts as random load only for Loss of Offsite Power (LOOP) after a time delay of 40s on DG 1A-A, 50s on DG 1B-B, 60s on DG 2A-A and 70s on DG 2B-B.

5.4 For each diesel generator, three cases are analyzed: Loss of Offsite Power (LOOP), LOOP with Safety Injection Phase A (SIA) and LOOP with Safety Injection Phase B (SIB). Therefore, a total of 12 cases are evaluated in this calculation. The loads and their operating time data is extracted from ETAP database (Attachment 5) and documented on Appendix A - Diesel Generator Loading & Starting Times.

5.5 The ETAP output reports (Appendices B, C, D, & E) generated for this calculation (R0) are saved on a Compact Disc (CD) attached for separate electronic storage in EDMS as Abode "pdf" files found under this calculation number and revision.

5.6 Random load of largest motor (75hp, Section 5.3) is considered starting on top of the maximum transient loading which comes at 35s for period 0 to 180s for SIA and 184s for period >3min for SIB (Section 5.9). Since the loads are already considered running in the analysis, the difference between the starting and running loads is added to the maximum transient loading to account for the random load. Starting kW is determined using the equation KWSTART V

N/3 X VRATED X ILR x LRPF (refer ETAP database for ILR, LRPF and running kW)

Diesel Generator 1A-A (128-9D): Starting 155.66kW, Running 48.91kW, A 106.75kW Diesel Generator 1B-B (132-9D): Starting 155.77kW, Running 51.72kW, A 104.05kW Diesel Generator 2A-A (136-8D): Starting 155.77kW, Running 51.72kW, A 104.05kW Diesel Generator 2B-B (140-9D): Starting 155.77kW, Running 51.72kW, A 104.05kW The larger size random load of 177hp (Cont Room A/C A-A Cprsr) for DG lA-A, 237hp (Shdn

'Bd Room B-B Cprsr) for DG 1B-B and 250hp (Elec Bd Room A/C Compressor) for DG 2A-A and 2B-B could start anytime after a time delay of 6 minutes. The worst case transient kW load (out of all four DGs) for period _>6amin which appears at 360s for SIB is approximately 4400kW (see Time v/s MW plots in Appendix F). The calculated worst case starting kW for the random load (250hp motor) is 349.2kW (-V3x0.460x1826x0.24). The running load included in the analysis for this motor is 141.3kW. The additional load which will come due to random start of this motor is 207.9z208kW (349.2-141.3) resulting in peak load of 4608 (4400+208)kW at 360s.

Therefore, the worst case transient loading with 250hp motor as random load is bounded by the worst case transient loading with 75hp motor as random load evaluated in Section 5.9.

Similarly the worst case transient kW loading (real power output) during LOOP is approx.

3500kW for 0-180 seconds and 3800kW for 180 seconds to end (App. F) which includes running load of 152.6kW for the 200hp fire pump. Starting load of this motor is calculated as 253.8kW (-/3x0.460x1180x0.27). Starting of this 200hp motor as random load will add 101.2z102kW (delta between starting and running load) resulting in worst case transient kW loading of 3602 (3500+102)kW for 0-180 seconds and 3902 (3800+102)kW for 180 seconds to end. This transient loading is bounded by the worst case transient loading evaluated in Section 5.9.

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 14 SHEET 19 5.7 Since ETAP motor starting analysis does not allow breakers to change state, the transformers are all energized prior to any load additions. This is acceptable as per Section 4.10.

5.8 In the ETAP analysis, ERCW pump motors are considered to be operating at 98% (Ref. 3.7).

However, the increased head and flow demand for the upgraded and refurbished ERCW pumps will place more demand on the motor but not exceeding 805 brake horsepower (Ref.

DCN 52920). This will result in increase of ERCW loading by 16.9+j6.5kVA (increase for 5hp is calculated proportionately from ETAP loading at 100% and 101%). This load is added to the ETAP load to calculate the total load on the DGs.

5.9 DG Load Computations The following computations show the total load on each DG and the available margin. Table 1 shows the maximum kW and kVA loading on each DG out of all three cases (LOOP, LOOP+SIA, and LOOP+SIB) and the event/time at which the maximum load occurs (App. F).

Table 2 shows the DG loading under LOOP only (no accident). The load information extracted from ETAP plots also includes the manually added loads at 1800 seconds (Section 5.2). However, since the most limiting rating applies after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, these loads are excluded from the computations for 0-2 hours (Note 6).

5.9.1.

Load Computations (Load Carrying Capability)

The following computations in Tables 1 and 2 show the maximum steady state (running) load of each DG during LOOP+LOCA and LOOP only for the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of the events.

These tables represent the total steady-state running load of all sequenced loads plus base continuous load on each DG. Load listed in Table 1 is from the ETAP reports for the worst load scenario during LOOP+LOCA with SIB and in Table 2 is just with LOOP event.

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 20 TABLE 1 (DG Loading LOOP+LOCA)

Maximum Steady-State Running Load, 0 hrs to 2 hrs*

1 A-A Minimum 1 A-A 1B-B 2A-A 2B-B Short-Time Ratina Minimum Marain (%)

kW (ETAP Plot) 4318.45 4188.12 4115.96 4228.79 4840 12.4 Event/Time SIB 1810s SIB 1810s SIB 1810s SIB 1810s Manual Action (Note 1)

(-)1 10.75

(-)110.75

(-)35.75

(-)30.00 DCN 53437 (Note 3) 7.44 3.72 7.44 3.72 Spare Charger (Note 3) 29.32 29.32 Charger Ct limit (Note 8) 15.60 15.60 15.60

.15.60 DCN55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW.**.

16.90 16.90

'16.90 16.90 CCP (Note 9)

(-)29.00

(-)29.00

(-)29.00

(-)29.00 24V CAP Chgr (Note 12)

, 9.4 Total 4220.51 4115.78 4102.42 4237.20

• kVA (ETAP Plot) 4958.06 4832.16 4724.42 4861.87 Event/Time SIB 1810s SIB 1810s SIB 1810s SIB 1810s 6050 19.3 Manual Action (Note 1)

(-)110.75

(-)110.75

(-)35.75

(-)30.00 DCN 53437 (Note 3)

(-)6.28

(-)3.14

(-)6.28

(-)3,14 Spare Charger (Note 3) 39.10 39.10 Charger Ct limit (Note 8) 19.50 19.50 19.50 19.50 DCN 55076 (Note 4) 1.66 1.66 1.66 1.66 ERCW**..

18.11 18.11 18.11 18.11 CCP (Note 9)

(-)30.41

(-)30.41

(-)30.41

(-)30.41 24V CAP Chgr (Note 12) 14.1 Total 4849.89 4766.23 4705.35 4876.69 Maximum Steady-State Runnina Load 2 hrs to End)**

1A-A 1B-B 2A-A 2B-B Continuous Minimum Rating Margin (%)

kW (ETAP Plot) 4318.45 4188.12 4115.96 4228.79 4400 6.9 Event/Time SIB 7200s SIB 7200s SIB 7200s SIB 7200s Manual Action (Note 2)

(-)75.00

(-)75.00 7.44 3.72 DCN 53437 (Note 3) 7.44 3.72 Spare Charger (Note 3) 29.32 29.32 Charger Ct limit (Note 8) 15.60 15.60 15.60 15.60 DCN 55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW..*.

16.90 16.90 16.90 16.90 CCP (Note 9)

(-)29.00

(-)29.00

(-)29.00

(-)29.00 CCSP (Note 10)

(-)290.9

(-)290.9 AFW (Note 11)

(-)162.6

(-)162.6

(-)162.6

(-)162.6 24V CAP Chgr (Note 12) 9.4 Total 4093.66 3698.03 3975.57 3813.70 kVA (ETAP Plot) 4958.06 4832.16 4724.42 4861.87 5500 14.5 Event/Time SIB 7200s SIB 7200s SIB 7200s SIB 7200s Manual Action (Note 2)

(-)75.00

(-)75.00

(-)6.28

(-)3.14 DCN53437 (Note 3)

(-)6.28

(-)3.14 Spare Charger (Note 3) 39.10 39.10 Charger Ct limit (Note 8) 19.50 19.50 19.50 19.50 DCN55076 (Note 4) 1.66 1.66 1.66 1.66 ERCW***..

18.11 18.11 18.11 18.11 CCP (Note 9)

(-)30.41

(-)30.41

(-)30.41

(-)30.41 CCSP (Note 10)

(-)317.74

(-)317.74 AFW (Note 11)

(-)186.24

(-)186.24

(-)186.24

(-)186.24 24V CAP.Chgr (Note 12) 14.1 Total 4699.40 4298.0 4554.86 4402.71

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 21 TABLE 2 (DG Loading LOOP Only)

Maximum Steady-State Running Load, 0 hrs to 2 hrs*

1A-A 1 B-B 2A-A 213-13 Short-Time Rating Minimum Margin (%)

kW (ETAP Plot) 3490.60 3416.70 3543.76 3626.33 4840 23.7 Event/Time LOOP 1810s LOOP 1810s LOOP 1810s LOOP 1810s EGT Htrs & Fans (Note 7) 24.70 24.70 24.70 24.70 DCN 53437 (Note 3) 7.44 3.72 7.44 3.72 Spare Charger (Note 3) 29.32 29.32 Charger Ct limit (Note 8) 15.60 15.60 15.60 15.60 DCN55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW*...

16.90 16.90 16.90 16.90 CCP (Note 9)

(-)29.00

(-)29.00

(-)29.00

(-)29.00 24V CAP Chgr (Note 12) 9.4 Total 3528.11 3479.81 3590.67 3689.44 kVA (ETAP Plot) 3936.49 4123.98 3963.21 4064.93 6050 31.0 Event/Time LOOP 1810s LOOP 181 Os LOOP 181 Os LOOP 181 Os EGT Htrs & Fans (Note 7) 3.46 3.46 3.46 3.46 DCN 53437 (Note 3)

(-)6.28

(-)3.14

(-)6.28

(-)3.14 Spare Charger (Note 3) 39.10 39.10 Charger Ct limit (Note 8) 19.50 19.50 19.50 19.50 DCN 55076 (Note 4) 1,.66 1.66 1.66 1.66 ERCW....

18.11 18.11 18.11 18.11 CCP (Note 9)

(-)30.41

(-)30.41

(-)30.41

(-)30.41 24V CAP Chgr (Note 12) 14.1 Total 3942.53 4172.26 3983.35 4113.21 Maximum Steady-State Running Load, 2 hrs to End)**

1A-A 1B-B 2A-A 2B-B Continuous Minimum Rating Margin (%)

kW (ETAP Plot) 3490.60 3416.70 3543.76 3626.33.

4400 22.08 Event/Time LOOP 7200s LOOP 7200s LOOP 7200s LOOP 7200s EGT Htrs & Fans (Note 7) 24.70 24.70 24.70 24.70 DCN 53437 (Note 3) 7.44 3.72 7.44 3.72 Spare Charger (Note 3) 29.32 29.32 Charger Ct limit (Note 8) 15.60 15.60 15.60 15.60 DCN55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW*..

16.90 16.90 16.90 16.90 CCP (Note 9)

(-)29.00

(-)29.00

(-)29.00

(-)29.00 CCSP (Note 10)

(-)290.9

(-)290.9 AFP (Note 11)

(-)162.6

(-)162.6

(-)162.6

(-)162.6 24V CAP Chgr (Note 12) 9.4 Total 3365.51 3026.31 3428.07 3235.94 kVA (ETAP Plot) 3936.49 4123.98 3963.21 4064.93 5500 30.96 Event/Time LOOP 7200s LOOP 7200s LOOP 7200s LOOP 7200s EGT Htrs & Fans (Note 7) 3.46 3.46 3.46 3.46 DCN 53437 (Note 3)

(-)6.28

(-)3.14

(-)6.28

(-)3.14 Spare Charger (Note 3) 39.10 39.10 Charger Ct limit (Note 8) 19.50 19.50 19.50 19.50 DCN 55076 (Note 4) 1.66 1.66 1.66 1.66 ERCW*...

18.11 18.11 18.11 18.11 CCP (Note 9)

(-)30.41

(-)30.41

(-)30.41

(-)30.41 CCSP (Note 10)

(-)317.74

(-)317.74 AFP (Note 11)

(-)186.24

(-)186.24

(-)186.24

(-)186.24 24V CAP Chgr (Note 12) 14.1 Total -

3756.29 3668.28 3797.11 3609.23

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 22 5.9.2 Load Computations (Motor Starting Capability)

The acceptability of the electric demand placed on the DGs is based on the maximum motor starting capability (Ref. Sec. 4.6) for each associated time period which is labeled as Cold Engine and Hot Engine capabilities. These capabilities are compared with the maximum transient loading (starting + running) to determine acceptability. If the maximum transient loading is less than the limit, then the DG is considered to maintain acceptable voltage and frequency.

TABLE 1 (DG Loading LOOP+LOCA)

Maximum Transient Loading (Real Power), 0 to 180 sec 1 A-A 1 B-B 2A-A 213-13 Cold Engine Caoabilitv kW (ETAP Plot) 3937.65 3520.30 3459.14 3878.36 4785 Eventlqime SIA 35s SIA 35s SIA 35s SIA 35s Random-*

106.75 104.05 104.05 104.05 DCN 53437 (Note 3) 7.74 3.72 7.74 3.72 Spare charger (Note 3) 29.32 29.32 ChargerCt limit (Note 8) 15.60 15.60 15.60 15.60 DCN 55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW****

16.90 16.90 16.90 16.90 CCP (Note 9)

(-)29.00

(-)29.00

(-)29.00

(-)29.00 24V CAP Chgr (Note 12) 9.4 Total 4057.51 3662.76 3585.7 4020.82 Maximum Transient Loading (Real Power), 180 sec to End 1 A-A 1 B-B 2A-A 2B-B Hot Engine Capability kW (ETAP Plot) 4736.24 4498.05 4481.74 4755.44 5073 Event/Time SIB 184s SIB 184s SIB 184s SIB 184s Random**

106.75 104.05 104.05 104.05 DCN 53437 (Note 3) 7.44 3.72 7.44 3.72 Spare Charger (Note 3) 29.32 29.32 Charger Ct limit (Note 8) 15.60 15.60 15.60 15.60 DCN.55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW*...

16.90 16.90 16.90 16.90 CCP (Note 9)

(-)29.00

(-)29.00

(-)29.00

(-)29.00 CCSP (Note 10)

(-)290.9

(-)290.9 AFP (Note 11)

(-)162.6

(-)162.6

(-)162.6

(-)162.6 24V CAP Chgr (Note 12) 9.4 Total 4693.20 4187.01 4445.4 4444.40 Maximum Step Load Increase (Apparent Power), 0 sec to End

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 23 TABLE 2 (DG Loading LOOP Only)

Maximum Transient Loadina (Real Power). 0 to 180 sec lB-B 28-B Cold Engine 1 A-A 1 B-B 2A-A 213-B Cold Engine Carpabilitv kW (ETAP Plot) 3354.31 3140.65 3243.48 3626.65 4785 Event/Time LOOP 90s LOOP 90s LOOP 90s LOOP 90s EGT Htrs & Fans (Note 7) 24.70 24.70 24.70 24.70 Random-**

106.75 104.05 104.05 104.05 DCN 53437 (Note 3) 7.44 3.72 7.44 3.72 Spare charger (Note 3) 29'32 29.32 Charger Ct limit (Note 8) 15.60 15.60 15.60 15.60 DCN 55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW****

16.90 16.90 16.90 16.90 CCP (Note 9)

(-)29.00

(-)29.00

(-)29.00

(-)29.00 24V CAP Ohgr (Note 12) 9.4 Total 3498.57 3307.81 3394.44 3793.81 Maximum Transient Loading (Real Power), 180 sec to End 1A-A 1B-B 2A-A 2B-B Hot Engine Capability kW (ETAP Plot) 3649.44 3767.84 3840.36 3817.07 5073 Event/Time LOOP 360s LOOP 360s LOOP 360s LOOP 360s EGT Htrs & Fans (Note 7) 24.70 24.70 24.70 24.70 Random*-

106.75 104.05 104.05 104.05 DCN 53437 (Note 3) 7.44 3.72 7.44 3.72 Spare Charger (Note 3) 29.32 29.32 Charger Ct limit (Note 8) 15.60 15.60 15.60 15.60 DCN 55076 (Note 4) 1.87 1.87 1.87 1.87 ERCW*..

16.90 16.90 16.90 16.90 CCP (Note 9)

(m)29.00

(-)29.00

(-)29.00

(-)29.00 CCSP (Note 10)

(-)290.9

(-)290.9 AFP (Note 11)

(-)162.6

(-)162.6

(-)162.6

(-)162.6 24V CAP Chgr (Note 12) 9.4 Total 3631.1 3481.5 3828.72 3530.73 1

Maximum Step Load Increase (Apparent Power), 0 sec to End 1 A-A 18-B 2A-A 2B-B Generator Step Load Capability kVA (ETAP Plot) 3641.55 3725.29 3718.84 3721.55 8000 Event/Time LOOP 20s LOOP 20s LOOP 20s LOOP 20s EGT Htrs & Fans (Note 7) 3.46 3.46 3.46 3.46 Random***

106.75 104.05 104.05 104.05 CCP (Note 9)

(-)30.41

(-)30.41

(-)30.41

(-)30.41 Total 3721.35 3802.39 3795.94 3798.65 Automatic load-sequencing only, no operator actions included.

• • Includes all operator actions (load additions). It is noted that some manual load additions may occur prior to 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. However, for the purpose of determining the worst-case design margin, all operator actions (maximum load addition) are taken after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> when the most limiting rating applies.

Section 5.6

• • • • Section 5.8

CALCULATION SHEET CALC NUMBER:

EDQOOO-999-2008-0014 REV. 14 SHEET 24 Note 1: The load shown in the ETAP plots (Appendix F) includes manually added load of 110.75kW (75kW for Hydrogen Elec Recombiners and 35.75kW for Perm Hydrogen Mitigation system) for DG 1A-A and 1B-B, 35.75kW and 30kW (Perm Hydrogen Mitigation System) for DG 2A-A and 2B-B respectively at 30 minutes (Section 5.2 &

Appendix G). Therefore, to determine the load due to automatic load sequencing, the manually added loads are subtracted from the load shown in the ETAP plots.

Note 2: Includes a manually added load of 35.76kW for Perm Hydrogen Mitigation System only. Load for Hydrogen Elec Recombiners (75kW) is not included since these are not required for unit shutdown. Per AOI-35 (Ref. 3.21) and Unit 1 Technical Specifications (TS, Ref. 3.4), even with both the H2 Elec Recombiners inoperable, safety function is maintained provided H2 igniters (Hydrogen Mitigation Sys) are operable. Hydrogen Elec Recombiners for Unit 2 have been deleted by EDCR 52329.

Note 3: DCN 53437 adds two new 125VDC vital spare battery chargers 8-S & 9-S and replaces the existing battery chargers I, II, III, IV, 6-S & 7-S. The new charger load is 29.32+j25.86kVA or 39.1kVA (see calculation record of revision for R3) compared to the existing charger load of 25.6+j33.6kVA or 42.24kVA. The change in load is +3.72kW, -3.14kVA.

The transfer switch will allow only one spare charger in each pair (6-S, 8-S and 7-S, 9-S) to be used at a time. In the analysis one normal and one spare battery charger is considered to be operational on each DG. The spare charger load is also added to calculated load for DG 1B-B and 2B-B to account for the alternate feed to spare battery charger 6-S or 8S/7-S or 9-S in accordance with Section 4.13 since this load is not included in the ETAP runs.

Note 4: DCN 55076 replaces all the 125VDC DG battery chargers. The increase in load for each charger is 1.87kW, 1.66kVA (see calculation record of revision for R6)

Note 5: DCN 52711 replaces the Main Control Room Chillers A-A, B-B and Shutdown Board Room Chillers A-A, B-B. These chillers are fed from DGs lA-A, 1B-B and 2A-A.

Loading impact of the replacement of these chillers is documented in the calculation record of revision for R5. Based on the analysis, steady state (run) kW loading of the new chillers is less compared to the existing chillers and will thus result in reduction of steady state loading. The slight increase in steady state KVA loading for shutdown board room chillers is insignificant compared to the total load.

The worst case loading on DG 2B-B is not impacted by this modification.

The transient loading (start) of the new chillers is higher compared to the existing chillers. However, based on a review of the existing transient loading from ETAP plots in Appendix F and the new chillers loading, the loading at 360s, when the chillers are loaded on the DG, is still enveloped by the worst case transient loading at 184s.

Note 6: For the purpose of determining the worst case design margin, all operator actions (load additions and removal) are taken after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> when the most limiting rating applies.

Note 7: Added a load of 20kW for EGT Humidity Heaters (Bus 203-6D and 205-5D) and 4.7+j3.46kVA for CB Emergency Air CU Fans (Bus 203-2A and 205-2A) for DG 1A-A and 1B-B. These loads could operate upon Blackout conditions.

Note 8: Battery charger input load considered in Tables 1 and 2 is 29.32+j25.86kVA or 39.1kVA. With the battery charger in current limit mode the input current will increase from the rated 47.02A (page 2C) to 58.78A (47.02x1.25) and the power factor may slightly improve from 0.75 to 0.76 (based on proportional increase from 0.74 to 0.75 with load increase from 75% to 100%, Ref. 3.25). Based on this

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 25 information, the charger load in the current limit mode is calculated as 37.12+j31.75kVA or 48.85kVA. Thus the increase in charger load from 100% load to current limit mode will be 7.80kW / 9.75kVA. There are two chargers on each DG, therefore, the total load increase on each DG will be 15.60kW /19.5OkVA.

Note 9: Calculation EPMGDU041593 summarizes the results of EPMHV070189 for the Centrifugal Charging Pumps (CCP). Review of the new curves in Attachment 8 (which are nearly identical) shows that at the maximum flow (212 gpm) the horsepower would be 500 HP (or 515 HP at the motor). At.the accident condition of 560 gpm both pumps would remain below 640 horsepower (or 659 HP at the motor). Based on this and a nameplate horsepower rating of 600 HP, the accident value listed in table 7.1 of EPMGDU041593 will be changed from 116% to 110%

(Section 2.5). This will reduce the HP on the Centrifugal Charging Pump motors from 695 HP to 659 HP (36HP). The total load decrease on each DG will be 29kW /

30.41kVA (value determined from ETAP).

Note 10: CCSP pumps 1B-B and 2B-B are not required to operate during accident condition per Section 4.15, therefore, these pumps will be turned off after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> into the accident events, hence the total load on each DG 1B-B and 2B-B will be decreased 290.9KW/127.8 KVAR (value determined from ETAP) (Calculated value of 317.74 KVA). All other CCSP pumps 1A-A, 2A-A and C-S pumps will continue to operate on their respective boards to support accident events.

Note 11: For the limiting case large break LOCA with all ECCS Pumps running, the steam generators will remain filled and Aux Feedwater Pump (AFW) will operate on mini flow at 170 gpm with a HP of less than 400HP after two hours (Appendix 4 of EPMGDU041593 and Section 3.2.1C of WBN System Description for WBNSDD-N3-3B-4002). This will reduce the HP on the Aux Feedwater Pump motors from 600HP to 400HP. The total load decrease on each DG will be 162.6kW / 186.24kVA.

Note 12: PER 464997 accounts the load for alternate feeder of 24V CAP Battery Charger No 1 fed from 480V RMOV Board 2A1-A/16F1 (Node 239 - 16F1) for Diesel Generator 2A-A. The total load increase on DG 2A-A will be 9.4kW / 14.1 kVA (value determined from ETAP).

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 26 5.10 Effect of Frequency Variation on DG loading The following computations determine the total steady state load on each DG and the available margin when DG frequency is increased to 60.1Hz from the rated frequency of 60Hz. Loading shown in the following table for 60Hz has been extracted from "Maximum Steady-State Running Load, 2Hrs to End" from Table 1 of Section 7.2. The highest steady state loading has been. used which envelopes all other steady state loading scenarios.

The Hz variation factor = (Maximum Hz/Rated Hz) 3 Section 3.2 of Ref. 3.26 (60.1/60)3

= 1.005 Maximum Steady-State Running Load, 2 hrs to End) lA-A lB-B 2A-A Continuous Minimum 1A-A 1 B-B 2A-A 2B-B Continuous Ratina Minimum Marain (%)

Total KW at 60 Hz 4093.66 3698.03 3975.57 3813.70 4400 6.9 Total KW at 60.1 Hz 4114.13 3716.52 3995.45 3832.77 4400 6.4 Load multiplication factor

= 1.005 This page added by R13

CALCULATION SHEET CALC NUMBER:

EDQOOO-999-2008-0014 REV. 16 SHEET 27 6.0 SUPPORTING GRAPHICS Figure Title 1

1 A-A DG LOOP - Apparent Power Output 2

1A-A DG LOOP - Real Power Output 3

1 A-A DG LOOP/SIA - Apparent Power Output 4

1 A-A DG LOOP/SIA - Real Power Output 5

1A-A DG LOOP/SIB - Apparent Power Output 6

1A-A DG LOOP/SIB - Real Power Output 7

1 B-B DG LOOP - Apparent Power Output 8

1 B-B DG LOOP - Real Power Output 9

1 B-B DG LOOP/SIA - Apparent Power Output 10 1 B-B DG LOOP/SIA - Real Power Output 11 1 B-B DG LOOP/SIB - Apparent Power Output 12 1B-B DG LOOP/SIB-Real Power Output 13 2A-A DG LOOP - Apparent Power Output 14 2A-A DG LOOP - Real Power Output 15 2A-A DG LOOP/SIA - Apparent Power Output 16 2A-A DG LOOP/SIA - Real Power Output 17 2A-A DG LOOP/SIB - Apparent Power Output 18 2A-A DG LOOP/SIB - Real Power Output 19 2B-B DG LOOP - Apparent Power Output 20 2B-B DG LOOP - Real Power Output 21 2B-B DG LOOP/SIA - Apparent Power Output 22 2B-B DG LOOP/SIA - Real Power Output 23 2B-B DG LOOP/SIB - Apparent Power Output 24 2B-B DG LOOP/SIB - Real Power Output See Appendix F for DGs 1A-A, 1B-B, 2A-A and 2B-B load profiles.

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 7

REV. 16 ISHEET 28 7.0

SUMMARY

OF RESULTS 7.1 The following is a summary of DG loads compared to the DG ratings and the margin available (See Section 4.5 for DG ratings and 5.9.1 for computed DG loading):

7.1.1 Load Computations (Load Carrying Capability)

Table 1 (DG Loading LOOP+LOCA)

Maximum Steady-State Runnino Load. 0 hrs to 2 hrs*

1A-A I

IB-B I

2A-A I

2B-B Short-Time Minimum Ratina IMarain (%)

kW 4220.51 4115.78 4102.42 4237.2 4840 12.4 Event/Time SIB 1810s SIB 1810s SIB 1810s SIB 1810s kVA 4849.89 4766.23 4705.35 4876.69 6050 19.3 Event/Time SIB 1810s SIB 1810s SIB 1810s SIB 1810s Maximum Steady-State Running Load, 2 hrs to End)**

1A-A 1B-B 2A-A 2B-B Continuous Minimum Rating Margin (%)

kW 4093.66 3698.03 3975.57 3813.70 4400 6.9 Event/Time SIB 7200s SIB 7200s SIB 7200s SIB 7200s kVA 4699.40 4298.0 4554.86 4402,71 5500 14.5 Event/Time SIB 7200s SIB 7200s SIB 7200s SIB 7200s Table 2 (DG Loading LOOP Only)

Maximum Steady-State Running Load, 0 hrs to 2 hrs*

IA-A 1B-B 2A-A 2B-B Short-Time Minimum Rating Margin (%)

kW 3528.11 3479.81 3590.67 3689.44 4840 23.7 Event/Time LOOP 1810s LOOP 1810s LOOP 1810s LOOP 1810s kVA 3942.53 4172.26 3983.35 4113.21 6050 31.0 Event/Time LOOP 1810s LOOP 1810s LOOP 1810s LOOP 1810s Maximum Steady-State Running Load, 2 hrs to End)**

1A-A 1B-B 2A-A 28-B Continuous Minimum Rating Margin (%L kW 3365.51 3026.31 3428.07 3235.94 4400 22.08 Event/Time LOOP 7200s LOOP 7200s LOOP 7200s LOOP 7200s kVA 3756.29 3668.28 3797.11 3609.23 5500 30.96 Event/Time LOOP 7200s, LOOP 7200s, LOOP 7200s LOOP 7200s

• Automatic load-sequencing only, no operator actions included.

• • Includes all operator actions (load additions).

The blackout loading includes common accident loads including Emergency Gas Treatment System (EGTS), Control Room Emergency Ventilation System (CREVS), and Auxiliary Building Gas Treatment System (ABGTS).

CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 29 7.1.2 Load Computations (Motor Starting Capability)

Table 1 (DG Loading LOOP+LOCA)

Maximum Transient Loading (Real Power), 0 to 180 sec Maximum Transient Loading (Real Power), 180 sec to End 1A-A 1B-B 2A-A 2B-B Hot Engine Capability I

kW 4693.20 4187.01 4445.4 4444.4 5073 Event/Time SIB 184s Sp SIB 184s ISIB 184s 0 s t

Maximum Step Load Increase (Apparent Power), 0 sec to End, Table 2 (DG Loading LOOP)

Maximum Transient Loading (Real Power), 0 to 180 sec Maximum Transient Loading (Real Power), 180 sec to End 1A-A I

1B-B I

2A-A 2B-B Hot Engine Capability kW 3631.10 13481.50 3828.72 3530.73 5073 Event/Time I LOOP 360s neLOOP 360s IaLOOP 360s LOOP 360s Maximum Step? Load Increase (Apparent Power), 0 sec to End.

The blackout loading includes common accident loads including Emergency Gas Treatment System (EGTS), Control Room Emergency Ventilation System (CREVS), and Auxiliary Building Gas Treatment System (ABGTS).

I CALCULATION SHEET CALC NUMBER: EDQOOO-999-2008-0014 REV. 16 SHEET 30 7.2 Effect of Frequency Variation on DG Loading Maximum Steady-State Running Load, 2 hrs to End)

(See Section 5.10) 1A-IB-B 2A-A 2B-B Continuous Minimum I

I Rating Margin (%)

Total KW at 60 Hz 4093.66 3698.03 3975.57 3813.70 4400 6.9 Total KW at 60.1 Hz 4114.13 3716.52 3995.45 3832.77 4400 6.4

8.0 CONCLUSION

S Following conclusions have been drawn based on the DG loading analysis and the results in Section 7.0:

8.1 The calculated loading for the automatically sequenced loads plus the required manual action loading is within the DG ratings and motor starting capability for all DGs, all time periods, and all design basis events (LOOP, LOOP + SI Phase A, and LOOP + SI Phase B).

There is adequate margin and load diversity to allow manually applied loads (i.e. hydrogen mitigation system) to be started prior to or after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

8.2 All DGs will maintain acceptable Voltage and Frequency throughout the load sequence for all time periods and all DBEs.

8.3 The loading on all DGs with the DG operating at 60.1 Hz is within the DG continuous rating specified in Section 4.5.

9.0 SPECIAL REQUIREMENTS/LIMITING CONDITIONS None

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 EDG Loading Tables depicting EDG loads with one unit in LOOP+LOCA and the second unit in LOOP E-23

L*

EDG Load Carrying Capability Unit 1 in accident (LOOP+LOCA) and Unit 2 non-accident (LOOP only)

Table 1 Maximum Steady-State Running Load, 0 hrs to 2 hrs*

1A-A 1 B-B 2A-A 2B-B Short-Time Ratina kW 4220.51 4115.78 3590.67 3689.44 4840 kVA 4849.89 4766.23 3983.35 4113.21 6050 Maximum Steady-State Runnina Load, 2 hrs to End)**

Unit 2 in accident (LOOP+LOCA) and Unit 1 non-accident (LOOP only)

Table 2 Maximum Steady-State Running Load, 0 hrs to 2 hrs*

Maximum Steady-State Running Load, 2 hrs to End)**

Automatic load-sequencing only, no operator actions included.

• • Includes all operator actions (load additions).

EDG Motor Starting Capability Unit 1 in accident (LOOP+LOCA) and Unit 2 non-accident (LOOP only)

Table 1 Maximum Transient Loadina (Real Power) 0 to 180 sec Maximum Transient Loading (Real Power), 180 sec to End 1A-A 1B-B 2A-A 212B-B Hot Engine Capability 4693.20 4187.01 3828.72 3530.73 5073 M~imiim ~t~en Load Tnr~r~~~ (Ann~r~nt Pnw~rY 0 ~c tn End Maxi u

Sten LoadIncrease (AnDarent Power) 0 sec to End Unit 2 in accident (LOOP+LOCA) and Unit I non-accident (LOOP only)

Table 2 Maximum Transient Loading (Real Power), 0 to 180 sec 1A-A 1

B-B 2A-A 2B-B Cold Engine Camabilitv 3498.57 3307.81 3585.7 4020.82 4785 Maximum Transient Loading (Real Power). 180 sec to End lA-A l B-B 2A-A 2B-B Hot Engine Capability 3631.10 j3481.50 4445.4 4444.4 5073 Maximum Step Load Increase (Apparent PowerL, 0 sec toEn End Maximum ite Load Inres r~ren....

0 ecto n

ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 EDG Motor Starting Capability E-26

.t I 4y C

Calc EDQC00-999-2008-0014, R0, Page 1 of 4 W

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f OVVRWn c.

301 South Church Street Slation Square, Suite 100 Rocky Mount, NC 27804 Phone: (919) 977-2720

1WX, (510) 929-0725 FAX:

(919) 446-1134

.. z--.

APPENDIX 1,PAGE 1 T141

~4O.

982 TELEFAX DATE:

Juhly 151.. 1-994 -

COMPANY:

.TVA -

rCotp-. Rnhinegring-FAX NUMBER:

61.5/365-150M ATTENTION, Mark-D.

Bom.an REFE0ENCE-EQ2 11otor Starting 'Capahjlt.

FROM:

Donald 121, 'Theazzi, IF YOU DO NOT RECEIVE ALL PAGES LISTED, PLEASE CALL EENSION 2_.1L PAGES (INCLUDING COVER SHEET): -

Dear Mr.

Bowman:

I have reviewed the DIESEL GENERATOR MAXIMUM KW CAPABILITY analysis for the Sequoyah and Watts Bar EDG's which you transmitted to me on 6/23/94.

The analysis is acceptable and therefore derating of the EDO motor starting capability is not required for the specified l1511F engine intake air temperature.

Youurs very truly, RKW.POWER

SYSTEMS, INC.

Donald D. Galeazzi

APPENDIX 1, PAGE 2 It, odyJun P2) 19 4 lWAB PM To-I fon.GAj*4 I~ tgMrj~~

,M, 1Ž Calc EDQ000-999-2008-0014, RO, Page 2 of 4 Tennessee Valley Authority DIESEL GENERATOR MAXIMUM KW CAPABILITY Sequoyah Nuclear Plant (SQN)

Watts Bar Nuclear Plant (WBN) 1.

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APPENDIX 1, PAGE 3 Calc EDQOO0-999-2008-0014, RO, Page 3 of 4 The intent of this document is to establish the maximum KW capability of the SQNtWBN diesel generators (DG) for starting motors in incremental steps during a design basis load sequence. The SQN/WBN DGs (TVA Contracts 71C61-92652 and 74C63-83090) are powered by two EMD 16-645E4B diesel engines operating in tandem. The generators are manufactured by Electric. Products and have a guaranteed efficiency of 96.6% at full rated load. The DG set ratings at 900 rpm, 901F intake air, and elevations less than 10,000 feet are!

2000 hrlyr: 6640 (BHP-tandem) x 0.746 (KWIHP) x 0.966 = 4785 KW 30 miniyr:

7040 (BHP-tandam) x 0.746 (KWIHP) x 0.966 5 5073 KW Each engine is equipped with a turbocharger which is driven by the engine gear train during the first three minutes of operation. After three minutes, the engine exhaust gas is sufficient to drive the turbocharger off the engine gear train by means of an over-riding clutch. Therefore, there are two levels of engine capability; one for a "cold" turbocharger and one for a "hot" turbocharger.

MKF/PSD Report 6981 -BBI establishes that the maximum KW capability of the "cold" engine for motor starting (in small steps such as during a load sequence) Is the 2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> rating at 906F. The maximum KW capability of the "hot" engine: Is the 30 minute rating at 909F. MK/PSD Report 6981-8A2 establishes that any derating of the engine capability for motor starting transients (short durations of approximately 2 to 5 seconds) is dependent solely on the density of the intake air charge, This density is affected by air temperature as well as elevation, The baseline temperature/elevation for the EMD 16-645E4B engine ratings is 901F

@ 10,000 feet above sea level. Both SQIN and WBN DG buildings are situated at less than 800 feet elevation with maximum intake air temperatures of less than 1 15°F. The U.S. Standard Atmosphere3 yields a density ratio of 0,7385 @ 10,000 feet compared to sea level conditions, The density ratio at 800 feet is approximately 0,98, Thus, there is an increase in air density of about 33% ai 800 feet versus 10,000 feet, The decrease in air density caused by an increase in temperature from 90OF to 115° is-approxImately 4%. it is seii that the increase MKWPSD Rep'ort No. 5981-8B. 12.21-e8.TVA Contract e8NJL-74472A, "'Report Addressing and Basoalvirg Attachment 1 and Attachment 2 of TVA No. 958398 nriclucing Review oi Loaoing)"

MKIPSD Report No. 8981-BA, 12.21-88, TVA Contract G8NJL-74472A, "Establish the Rating of the EmergancV Diesel Generator and Provi-a Deration Curves for Elevateo Ambient Combustion Air Temperatures" Mark'a Standata Handbook for Mechanical Engineers, Cooytight 1978, 1967, 1958 by McGraw-Hill, Inc.. Table 11,4.1 "U.S. Standard Atmosonere" 2

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Calc EDQM00-999-2008-0014, RO, Page 4 of 4 in intake air density gained at SON/WON site elevation is considerably greater than any decrease caused by elevated intake air temperature. Therefore, no darating of the DG maximum KW capability is required.

Based on the above discussion, the SQNWBN DG maximum KW capability for motor starting in the site service environment (intake air temperature less than 115*F and elevation less than 800 feet) is-,

"Cold" Engine (first 3 minutes of load sequence):

"Hot" Engine (fully turbocharged):

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ENCLOSURE Response to Action Item 26 From Appendix HH of NUREG-0847, Supplement 22 Excerpt from Unit 2 Submergence Evaluation E-31

CALCULATION SHEET CALC NUMBER: EDQ002-999-2008-0020

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6.0 COMPUTATION AND ANALYSIS This calculation uses the same methodology as discussed in Unit 1 calculation WBNEEBMSTI080009 (Ref. 3.8). Two major effects are identified in Section 8.5 of.Technical Instruction EEB-TI-8 (Ref. 3.6) that increase power supply current due to submerged electrical equipment One effect is leakage currents flowing through the water, and the other is additional mechanical drag imposed on rotating equipment The control power circuits are primary concerned with leakage currents, and motor circuits are concerned with additional mechanical drag.

The electrical equipment (both safety and non-safety components) inside primary containment that receive power from Class 1E boards were compiled by power sources and are listed in Appendix F. Cables which will be submerged but the associated power components located above the maximum submergence level of 720' are not listed in Appendix F (Section 5.8).

Schematics for each'identified component were reviewed to determine if the circuit for the submerged component is energized during an accident. Equipment is considered to be operating when a contact that may short as a result of flooding can start the equipment. If the circuit could be energized, then the additional loading on the power supply due to submergence is determined based on the type of load. For example if a submerged motor starts or a running motor is submerged, loading based on its lock rotor current is considered. Similarly for static loads like heaters it is considered to draw current equivalent to its protective device rating i.e. breaker trip rating, fuse rating or maximum trip current of the thermal overload. The load on control circuits that do not start equipment but pickup a relay or a status indicating light is neglected since this load is negligible compared to the operating loads. The effect of all submerged loads on a power supply is determined and the total load (accident plus submerged load) compared with the protective device's ratings. The affect of increased loading due to submergence on available board/bus voltage of the AC and DC auxiliary power system has also been evaluated. The components located above elevation 720' and affected by borated containment spray are evaluated in Appendix E.

In some cases, the loads that were identified as being energized were eliminated from the submergence load by determining that the components were at elevation above the flood level of 720 ft. This determination was accomplished by reviewing connection/physical drawings. However, components located above the elevation level of 720' and affected by the borated containment spray are evaluated in Appendix E.

Based on a review of calculations EDQ00299920080018 (Ref. 3.4) and EDQ00299920080019 (Ref. 3.7) and applicable wiring and schematic drawings for the affected components upon flooding inside the containment, analysis for AC and DC power supply systems has been performed in the following appendices:

Appendix A 120V AC Class 1E Vital Instrument Power System Appendix B 125V DC Class 1E Vital Power System Appendix C Miscellaneous type loads inside primary containment that are supplied power from Hydrogen Mitigation System Panels 2-DPL-268-1-A and 2-DPL-268-2-B Appendix D 6.9kV/480V Auxiliary Power System Appendix E Effect of borated containment spray on all the additional equipment located above the submergence level elevation of 720'. The evaluation addresses both the effects of borated spray on the various types of electrical equipment installed within containment and the effects on the class 1E distribution system Appendix F Lists the electrical equipment (both safety and non-safety components) inside primary containment that receive power from Class IE boards 7.0 SUPPORTING GRAPHICS None

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-t CALCULATION SHEET CALC NUMBER: EDQ002-999-2008-0020 EV. 0 ISHEET 11 ORIGINATOR:

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8.0

SUMMARY

OF RESULTS 8.1 The maximum loading due to accident and submerged (non-safety) load on 120V AC Vital Instrument Boards 2-I, 2-11, 2-11 and 2-IV (Ref. Appendix A - Tables 1 thru 5) is less than their associated inverter load limits of 14kVA for inverters 2-I & 2-11 and 10.5kVA for 2-Il1 & 2-IV (Appendix A of caic. WBNEEBMSTI120016; Ref. 3.1). Since the analysis in calc. EDQ00023620070003 (Ref. 2.2) considers the inverters to be loaded up to the load limit, there is no affect on the 125V DC system bus loading or the voltage due to submergence of loads.

The submerged loads on the 120V AC vital Class 1E power system do not cause the secondary protective devices to trip.

8.2 The maximum battery loading due to the accident and submerged load on 125V DC Vital Battery Boards III and IV is acceptable. Also the calculated battery terminal voltage with the increased loading is more than the minimum required voltage (Table 1 of Appendix B)

The submerged loads on the 125V DC vital Class lE power system do not cause the secondary protective devices to trip.

8.3 The maximum loading due to accident and submerged (non-safety) load on 120V AC Hydrogen Mitigation System Panels is less than their associated breaker rating (Ref. Appendix C). There is no affect of submergence of heaters fed from this panel on the loading or the bus voltages in the auxiliary power system since load equal to flail transformer rating is already included in the existing analysis in calc. EDQ00099920070002 (Ref. 2.3).

The submerged loads on these panels do not cause the secondary protective devices to trip.

8.4 The maximum loading due to accident and submerged (non-safety) load on 6.9kV and 480V boards is less than their associated transformer rating (Ref. Appendix D).

The submerged loads on the 480V Class 1E power system do not cause the secondary protective devices to trip. Locked rotor currents of the submerged loads plus the accident loads are well within the long time trip setting of the incoming breakers. The only equipment powered from 6.9kV Shutdown Boards located inside the containment is Pressurizer heaters which are tripped on LOCA. There is insignificant impact of additional loading due to submergence of components on the AC auxiliary power system voltages as discussed in Appendix D. Also there is no afect of submergence of heaters fed from heat trace panel on loading or the bus voltages on the auxiliary power system since load equal to full transformer rating is already included in the existing analysis in cale. EDQ00099920070002 (Ref. 3.3). j R1 8.5 The effects of borated containment spray on various types of electrical equipment located inside the containment and the Class IE distribution system is discussed in Appendix E. This containment spray has no adverse impact on the continued operation of safety related buses.

9.0 CONCLUSION

S The following conclusions are drawn based on the analysis in this calculation and the Section 8.0:

9.1 The additional loading on the 120V AC vital Class 1E power system due to submerged equipment does not cause any.

• secondary protective devices to trip nor does it overload the power supplies (inverters). The maximum load on inverters due to additional submerged load is within their specified rating. It also has no impact on the existing 125V DC power system analysis.

9.2 The additional loading on the vital 125V DC Class 1E power system due to submerged equipment does not cause any secondary protective devices to trip nor does nor does it adversely affect the battery sizing. The available voltage at the battery terminals is more than the minimum required voltage.

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.4t CALCULATION SHEET CALC NUMBER: EDQ002-999-2008-0020 REV. 0 SHEET 12 ORIGINATOR:

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9.3 The loading on the 120VAC Hydrogen Mitigation System Panels due to submerged equipment does not cause any secondary protective devices to trip nor does it overload the transformer. There is no impact on the bus loading or bus voltages in the existing AC auxiliary power system analysis.

9.4 The additional loading on the 6.9kV and 480V Class 1E power system due to submerged equipment does not cause any secondary protective devices to trip nor does it overload the power transformers. The effect of the non-safe shutdown submerged loads on the AC auxiliary power system is insignificant as explained in Appendix D.

The loading on the 120V AC Safety Injection Heat Trace Distribution Panel Al (0-DPL-234-Al/SIS) due to submerged equipment does not cause any secondary protective devices to trip. There is a slight overloading of the transformer but it is considered insignificant (see Appendix C). There is no impact on the bus loading or-bus voltages in the existing AC auxiliary power system analysis 9.5 There is no adverse impact on the Class IE systems (480V, 125VDC, 120VAC) due to Borated Containment Spray on theshutdown and non safe shutdown components located inside the containment 10.0 SPECIAL REQUIREMENTS / LIMITING CONDITIONS None 11.0 APPENDICES 11.1 Appendix A - 120V AC Vital Class 1E Power System Load Table 1 - 120V AC Vital Instrument Power Boards 2-1, 2-11, 2-111 and 2-1V Table 2 - 120V AC Vital Instrument Power Board 2-I (2-BD-235-1-D)

Table 3 -. 120V AC Vital Instrument Power Board 2-11 (2-BD-235-2-E)

Table 4 - 120V AC Vital Instrument Power Board 2-111 (2-BD-235-3-F)

Table 5 - 120V AC Vital Instrument Power Board 2-IV (2-BD-235-4-G) 11.2 Appendix B - 125V DC Vital Class 1E Power System Load Table 1 - 125V DC Vital Battery Boards.rll and IV Table 2 - 125V DC Vital Battery Board III (1-BD-235-3-F)

Table 3-125V DC Vital Battery Board IV (1-BD-235-4-G) 11.3 Appendix C - Hydrogen Mitigation System Panels 2-DPL-268-1-A and 2-DPL-268-2-B Load 11.4 Appendix D - AC Auxiliary Power System Evaluation (6.9kV & 480V Shutdown Boards, 480V RMOV Boards, 480V Reactor Vent Boards) 11.5 Appendix E - Borated Containment Spray Evaluation 11.6 Appendix F-Electrical Equipment List