Text

(Waterford 3) - Supplemental Information Supporting the License Amendment Request Regarding Proposed Change to Technical Specification 3/4.7.4 for Ultimate Heat Sink Design Basis Update
	ML18137A494
Person / Time
Site:	Waterford
Issue date:	05/17/2018
From:	Dinelli J; Entergy Operations
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	W3F1-2018-0025
	Download: ML18137A494 (163)
	v • d • e

Entergy Operations, Inc.

17265 River Road Killona, LA 70057-3093 Tel 504-739-6660 Fax 504-739-6678 jdinelli@entergy.com John C. Dinelli Site Vice President Waterford 3 10 CFR 50.90 W3F1-2018-0025 May 17, 2018 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Supplemental Information Supporting the License Amendment Request Regarding Proposed Change to Technical Specification 3/4.7.4 for Ultimate Heat Sink Design Basis Update Waterford Steam Electric Station, Unit 3 (Waterford 3)

Docket No. 50-382 License No. NPF-38

REFERENCES:

1. NRC Notice, Pre-submittal Meeting with Entergy Operations, Inc Regarding a License Amendment Request to Revise Technical Specification Table 3.7-3 for Waterford Steam Electric Station, Unit 3, May 15, 2017 [NRC ADAMS Accession Number ML17151A314].

2. Waterford 3 Slides for Presentation to the NRC on the Ultimate Heat Sink Amendment Request, June 1, 2017 [NRC ADAMS Accession Number ML17151A295].

3. NRC Letter, Summary of June 1, 2017, Public Meeting With Entergy Operations, Inc., regarding Planned License Amendment Request to Revise Technical Specification (TS) Table 3.7-3 and TS 3/4.7.4, Ultimate Heat Sink For Waterford Steam Electric Station, Unit 3, June 28, 2017

[NRC ADAMS Accession Number ML17174B226].

4. W3F1-2017-0050, License Amendment Request Proposed Change to Technical Specification 3/4.7.4 for Ultimate Heat Sink Design Basis, March 26, 2018 [NRC ADAMS Accession Number ML18085B196].

5. Waterford Steam Electric Station, Unit 3 - Supplemental Information Needed for Acceptance of Request for Licensing Action Re: Revision of Technical Specification 3/4.7.4, Ultimate Heat Sink (EPID L-2018-LLA-0080) May 4, 2018 [NRC ADAMS Accession Number ML18122A097].

W3F1-2018-0025 Page 2 of 2

Dear Sir or Madam:

By letter dated March 26, 2018 (Reference 4), Entergy submitted a License Amendment Request pursuant to 10 CFR 50.90 to revise Technical Specification 3/4.7.4 associated with the Ultimate Heat Sink for Waterford Steam Electric Station Unit 3 (Waterford 3).

By letter dated May 4, 2018 (Reference 5), the NRC notified Entergy that the NRC staff reviewed this submittal and determined that additional information is necessary to enable the staff to make an independent assessment regarding the acceptability of the proposed amendment in terms of regulatory requirements and the protection of public health and safety and the environment. Reference 5 includes a list of sufficiency items that are needed to make the application complete.

The sufficiency items requested by the NRC in Reference 5 are provided in the Enclosure to this letter. In addition, one editorial change has been made to one of the redlined Technical Specification pages.

This supplement does not alter the no significant hazards consideration or environmental assessment previously submitted by Entergy in letter W3F1-2017-0050 (Reference 4). There are no new regulatory commitments contained in this supplement. If you have any questions or require additional information, please contact John Jarrell, Regulatory Assurance Manager, at 504-739-6685.

I declare under penalty of perjury that the foregoing is true and correct. Executed on May 17, 2018.

Sincerely, JCD/JPJ/mmz

Enclosure:

Supplement to Proposed Technical Specification Change (includes 5 attachments) cc: Mr. Kriss Kennedy, Regional Administrator U.S. NRC, Region IV RidsRgn4MailCenter@nrc.gov U.S. NRC Project Manager for Waterford 3 April.Pulvirenti@nrc.gov U.S. NRC Senior Resident Inspector for Waterford 3 Frances.Ramirez@nrc.gov Chris.Speer@nrc.gov Louisiana Department of Environmental Quality Office of Environmental Compliance Surveillance Division Ji.Wiley@LA.gov

Enclosure to W3F1-2018-0025 Waterford Steam Electric Station, Unit 3 Supplement to Proposed Technical Specification Change (9 pages)

Enclosure to W3F1-2018-0025 Page 1 of 9 Sufficiency Item 1 Dry Cooling Tower fan backflow preventers are new to this LAR [License Amendment Request]. Provide a physical description of the backflow preventers. Discuss installation, operation and qualification of these new devices.

Entergy Response Entergy is removing the request for the NRC to consider the portion of the LAR concerning Backflow Preventers, Section 4.5.6, from consideration in this license amendment. Section 4.5.6 and the related commitment will be withdrawn. Attachments 1 and 2 to this Enclosure provide new marked up and clean pages to the Technical Specification to reflect this change to the LAR. These pages replace Attachments 1 and 2 to the original submittal in their entirety. Attachment 3 provides a revised List of Regulatory Commitments. Because all of the analyses performed in support of this amendment were performed both with and without the Backflow Preventers, the removal of this portion of the request does not change any of the analyses referenced in the original submittal.

Additional

References:

None

Enclosure to W3F1-2018-0025 Page 2 of 9 Sufficiency Item 2 Provide the basis for why the 3-day and 7-day temperature limits are specified, including their relation to meeting the requirements of Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36, Technical specifications, and the guidelines of Regulatory Guide 1.27, Revision 3, Ultimate Heat Sink for Nuclear Power Plants.

Entergy Response The 3-day and 7-day temperature limits are conservative average temperature limits used to bound the critical time periods discussed in Regulatory Guide 1.27 Revision 2. Regulatory Guide 1.27 states:

The meteorological conditions considered in the design of the sink should be selected with respect to the controlling parameters and critical time periods unique to the specific-design of the sink. For example, consider a dry cooling tower as the sink. The controlling parameter would be a dry bulb temperature, and the critical time period may be on the order of one hour. Therefore, an acceptable design basis meteorological condition for this sink would be the maximum observed (based on regional climatological information) one-hour dry bulb temperature. As another example, consider a cooling pond as the sink where the pond temperature may reach a maximum in 5 days following a shutdown. This maximum temperature should coincide with the most severe combination of controlling meteorological parameters for a 1-day period.

Therefore, three critical time periods should be considered: 5 days, 1 day, and 30 days (to ensure the availability of a 30-day cooling supply).

The Waterford 3 design has both dry and wet cooling towers so the Regulatory Guide 1.27 discussion for multiple critical time periods is applicable and the selected periods are unique to the plant design. ECM95-008 Section 4.2.1.1 summarizes that the calculation meets the Regulatory Guide 1.27 requirement to consider controlling meteorological parameters and critical time periods. For example, the highest recorded dry bulb temperature on the order of one hour, with a conservatively bounding recirculation effect, is the controlling parameter for the Dry Cooling Tower (DCT) for the peak heat load evaluation. The highest wet bulb temperature corresponding to the selected dry bulb temperature, with a conservatively bounding recirculation effect, is used as the controlling parameter for the Wet Cooling Tower (WCT) for the peak heat load evaluation. The critical time periods and associated ambient temperature limitations ensure that the ultimate heat sink meets the design calculation requirements for heat removal. The ambient temperature limits provide the initial conditions assumed in the design basis calculations. This corresponds to the 10 CFR 50.36(c)(2)(ii)(B)

Criterion 2 which states:

A process variable, design feature, or operating restriction that is an initial condition of a design basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

Technical Specification Table 3.7-3 provides the ambient temperature restrictions required for the specific fan configurations. The ambient temperature restrictions were based upon first identifying the critical time periods and then ensuring the time period chosen was conservative. Based upon the analysis of critical time period and associated bounding dry

Enclosure to W3F1-2018-0025 Page 3 of 9 bulb temperature, it can be seen that as the critical time period gets longer, the bounding average dry bulb temperature gets smaller. The table below (from WF3-ME-16-00001 and the Waterford 3 UFSAR) demonstrates this for several periods of interest:

Critical Time Period Bounding Average Dry Bulb Temperature 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months 102.0 °F 1 day 92.0 °F 3 day 89.0 °F 7 day 86.0 °F 30 day 84.7 °F This shows that using smaller critical time periods for the analysis is conservative because the analysis is based on higher bounding ambient average temperature for a longer period of time. This results in conservatively higher water consumption in the analysis. This is also consistent with the current analyses that use 3-day average temperature for the LOCA water consumption and 7-day average temperature for the tornado analysis.

ECM95-008 Section 5.1.12 describes the selection of the critical time period of one hour for evaluating peak heat load and corresponding peak CCW supply temperature. This is consistent with the Regulatory Guide 1.27 example provided earlier. This is the evaluation to ensure that design basis temperatures of safety related equipment is not exceeded. 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months is the appropriate time period based on the heat capacity (inertia) of the system. In addition, 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months average temperature is typically very close to the instantaneous temperature.

ECM95-008 Section 5.1.13 describes the selection of the critical time period of three days for evaluating accident water consumption. The water consumption analysis shows that water evaporation from the WCT is credited for between 6 and 12 days post-accident depending on the configuration. After that time, the DCT can handle all of the plant heat loads. Using the highest three day average dry bulb temperature for the entire 6 to 12 day water consumption event results in more water consumption than using the average temperature for actual longer water consumption periods.

As discussed in ECM95-008 Section 4.2.1.3.1, Engineering Report WF3-ME-16-00001 develops a bounding relationship between ambient wet bulb and ambient dry bulb temperatures for each critical time period. Lower wet bulb temperature for a given dry bulb is associated with lower relative humidity, which increases the evaporation rate for the WCT.

Therefore, the bounding low wet bulb temperature corresponding to the selected dry bulb temperature would be the appropriate controlling parameter for the Wet Cooling Tower (WCT) for the water consumption evaluations. Sensitivity studies proved that water consumption is higher when lower wet bulb temperature is used in the analysis.

ECM95-008 Section 5.3.5.5 describes the selection of the critical time period of seven days for evaluating tornado event water consumption. Seven days is conservative because the water consumption for the design basis tornado event is analyzed for more than 30 days, which is much longer than seven days. Using the highest seven day average dry bulb temperature for the entire tornado event results in more water consumption than using the average temperature for longer critical actual water consumption periods.

Enclosure to W3F1-2018-0025 Page 4 of 9 The Technical Specifications Table 3.7-3 fan requirements are based on UHS analyses with bounding meteorological conditions for the critical time periods with all DCT fans or 14 out of 15 DCT fans operable. In other words, there is no need to evaluate actual meteorological conditions as long as at least 14 DCT fans are operable, because the analyses for those configurations is based on bounding meteorological conditions. The analysis shows less severe meteorological conditions are required when more than one DCT fan is out-of-service (13 out of 15 DCT fans operable). Technical Specifications table 3.7-3 reflects the results of the analysis showing fan requirements that ensure the UHS is capable of providing sufficient cooling for at least 30 days to ensure that design basis temperatures of safety related equipment are not exceeded. Both one hour and three day dry bulb temperature forecasts will be monitored to ensure that expected ambient dry bulb temperatures will be consistent with the analysis. For a tornado watch or warning with one of the DCT fans associated with the missile protected portion of the DCT out of service, the seven day dry bulb temperature forecast will be monitored, consistent with the critical time period chosen for the tornado event analysis.

Waterford 3 has used the ambient temperature forecast method described in the LAR to study the temperature accuracy. The initial data (10 weeks of data over 3 months) indicates that the national weather service forecast for the local area are very accurate to slightly conservative (high) for predicting the upcoming three day and six day average temperatures.

As stated in the LAR, the plan is to use the six day average forecast along with the forecast high seventh day temperature to conservatively determine the forecast average seven day temperature.

Additional

References:

None

Enclosure to W3F1-2018-0025 Page 5 of 9 Sufficiency Item 3 Regulatory Requirements The NRC staff identified the following 10 CFR Part 50, Appendix A, General Design Criteria (GDC) as being applicable to the review of the impact of the change of the component cooling water temperature on containment pressure, temperature, and sump temperature response analysis:

GDC-38, Containment heat removal, insofar as it requires that a containment heat removal system be provided, and that its function shall be to rapidly reduce the containment pressure and temperature following a loss-of-coolant accident and maintain them at acceptably low levels;

GDC-50, Containment design basis, insofar as it requires that the containment and its associated heat removal systems be designed so that the containment structure can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated temperature and pressure conditions resulting from any loss-of-coolant accident; Supplementary Information Requested Section 4.5.5, second paragraph of the Enclosure to the licensee letter dated March 26, 2018 states, in part:

The design basis calculations were updated to demonstrate that component cooling water supplied at up to 120°F [degrees Fahrenheit] in the accident lineup adequately cools all safety related equipment, including the emergency diesel generators, containment fan coolers, shutdown cooling heat exchanger, high pressure safety injection pumps, low pressure safety injection pumps, containment spray pumps, system piping, and fuel pool cooling heat exchanger and maintains their design basis temperatures.

Section 4.5.5, second paragraph of the Enclosure to the licensee letter dated March 26, 2018 also states, in part:

The design basis calculations demonstrate that the ultimate heat sink is capable of supplying required component cooling water flow to all components at temperatures less than or equal to 120°F during peak accident heat load under bounding ambient conditions. Therefore, the supply temperature to safety related components after a design basis accident with a safety injection actuation signal will be controlled less than or equal to 120°F.

The above statements indicate that the component cooling water temperature supply temperature to containment fan coolers, shutdown cooling heat exchangers, and several pumps and heat exchanger is proposed to be increased from 115°F to 120°F. It would be expected that the containment pressure, temperature, and sump temperature response would be impacted due to this change.

Enclosure to W3F1-2018-0025 Page 6 of 9 In the requested supplement, provide the following information:

(a) The inputs and assumptions in the containment pressure, temperature, and sump temperature analysis with justification in case the conservatism in any of the inputs and assumptions has been reduced from the analysis of record.

(b) The inputs and assumptions for the net positive suction head analysis for the pumps that draw water from the sump in the recirculation mode, with justification, in case the conservatism in any of the inputs and assumptions has been reduced from the analysis of record.

(c) The graphical results of the analysis in (a) and (b) and the peak values.

Entergy Response The setpoint for controlling the component cooling water (CCW) supply temperature after a safety injection actuation signal (SIAS) is being changed from 115°F to 117.4°F. ECI91-036 concludes that the design basis instrument uncertainty for this control is 2.6°F. Therefore, 120°F bounds the CCW supply temperature that will be delivered to the components after an accident.

The current containment pressure and temperature analysis of record, ECS98-015 (EC-50235), was performed using the setpoint value for CCW supply temperature, 115°F, and using the setpoint plus a conservative 5°F uncertainty, 120°F. Therefore, the existing containment pressure and temperature analysis of record for the proposed setpoint change already covers 120°F, which bounds the new 117.4°F CCW supply temperature setpoint with design basis uncertainty. The only change is using the actual design basis uncertainty for the CCW supply temperature, 2.6°F, rather than the previously used 5°F.

Similarly, the analysis of record for the NPSH of the pumps that draw water from the sump in the recirculation mode, ECM07-001, NPSH Analysis of Safety Injection and Containment Spray Pumps, is also not impacted by the proposed SIAS CCW supply temperature setpoint change.

The inputs and assumptions in the containment pressure, temperature, and sump temperature analysis of record that account for uncertainty are as follows:

Values without Values with Input Uncertainty Uncertainty Initial Containment Pressure (psia) 15.7 15.95 Initial Containment Temperature (°F) 120 127 Containment Spray Riser Level (ft MSL) 149.5 142.5 CCW Supply Temperature (°F) 115 120 RWSP Temperature (°F) 100 107.5 CCW Flow to Containment Fan Coolers (gpm) 1200 1100

Enclosure to W3F1-2018-0025 Page 7 of 9 There are no changes from the analysis of record since the analysis of record already included analyses using the bounding 120°F CCW supply temperature. Therefore, there was no need to update the analysis of record for the containment pressure, temperature, and sump temperature and there is no reduction in the conservatism in any of the inputs and assumptions from the analysis of record.

The inputs and assumptions for the NPSH analysis for the pumps that draw water from the sump in the recirculation mode, relative to the containment analysis, are as follows:

Input Value Containment Pressure (psia) (throughout the event) 14.14 psia Sump Water Temperature (°F) 210 There are no changes from the analysis of record since the analysis of record does not use CCW supply temperature as an input. The analysis of record is based on a conservatively assumed sump water temperature and associated vapor pressure to minimize available vapor pressure and to maximize friction losses in the pump suction lines. Therefore, there was no need to update the NPSH analysis of record for the pumps that take suction from the sump in the recirculation mode and there is no reduction in the conservatism in any of the inputs and assumptions from the analysis of record.

The graphical results of the analyses for containment pressure and temperature and NPSH with peak values annotated are included in Attachment 4. The planned revision to the Waterford 3 UFSAR to incorporate this modification will include these results. The peak values are summarized in the following tables:

Results (peak values) Values without Values with for Cold Leg Break Uncertainty Uncertainty Peak Pressure (psia) 51.8 53.0 Peak Vapor Temperature (°F) 257.3 260.0 Peak Liquid Temperature (°F) 215.83 218.0 Results (peak values) Values without Values with for Hot Leg Break Uncertainty Uncertainty Peak Pressure (psia) 54.9 55.2 Peak Vapor Temperature (°F) 262.7 263.4 Peak Liquid Temperature (°F) 209.87 212.0 Additional

References:

1. ECM07-001, Revision 1 (EC-40296), NPSH Analysis of Safety Injection and Containment Spray Pumps.

2. ECS98-015, Revision (EC-50235), Containment P&T Response Analysis - Steam Generator Replacement Project.

Enclosure to W3F1-2018-0025 Page 8 of 9 Sufficiency Item 4 The LAR is based on an entirely new Ultimate Heat Sink Design Basis Reconstitution. The LAR did not provide adequate information to check the design inputs, assumptions, and methodology of the reconstitution effort. The NRC staff needs this information to perform a Safety Evaluation. Therefore, provide the body of Reference 7.20: ECM95-008 Revision 3 (EC52043), "Ultimate Heat Sink Design Basis." Provide only the front body of this document, without the attachments.

Entergy Response ECM95-008 Revision 3 (EC52043), Ultimate Heat Sink Design Basis, without the attachments, is provided as Attachment 5 to this enclosure.

Additional

References:

None

Enclosure to W3F1-2018-0025 Page 9 of 9 Additional Change Note that one of the attachments is a mark up to page 3/4 7-12 of Technical Specification 3/4.7.4, Ultimate Heat Sink. An editorial change has been made to the redline on this page.

Previously, 86 was lined out and replaced with 77. The redline has been changed to line out -9.86 which is to be replaced with -9.77. This change to the redline was made to ensure clarification of the change.

Enclosure Attachment 1 to W3F1-2018-0025 Proposed Technical Specification Changes (mark-up)

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c. This action applies only when UHS tornado required equipment is inoperable.

With a Tornado Watch or Warning in effect with the forecast 7 day average ambient dry bulb temperature greater than 74ºF, all 6 DCT tube bundles and all 9 DCT fans associated with the missile protected portion of both trains of the DCT shall be OPERABLE. With a Tornado Watch or Warning in effect with the forecast 7 day average ambient dry bulb temperature less than or equal to 74ºF, all 6 DCT tube bundles and at least 8 DCT fans associated with the missile protected portion of both trains of the DCT shall be OPERABLE. If the number of tube bundles or fans OPERABLE is less than required, restore the inoperable tube bundle(s) or fan(s) to OPERABLE status within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , or be in at least HOT STANDBY within WKHIROORZLQJ6 hours and in HOT SHUTDOWN withinthe following 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

Insert 2

d. When Table 3.7-3 dry bulb temperature restrictions apply with UHS fan(s) inoperable, determine the forecast ambient temperatures and verify that the minimum fan requirements of Table 3.7-3 are satisfied (required only if the associated UHS is OPERABLE). The more restrictive fan requirement shall apply when 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and 3 day average temperatures allow different configurations.

Insert 3

e. With either or both wet cooling tower basin cross-connect valves not OPERABLE for makeup, restore the valve(s) to OPERABLE status within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months or COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

Replace Table 3.7-3 with Insert 4 (see next page)

Insert

TABLE 3.7-3 ULTIMATE HEAT SINK MINIMUM FAN REQUIREMENTS PER TRAIN (1)

ALLOWABLE FAN COMBINATIONS 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months / 3 day average dry bulb temperature restrictions OPERABLE DCT Fans OPERABLE 15 14 13 WCT Fans 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months 3 day 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months 3 day 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months 3 day 8 88 ºF 77 ºF No Temperature Restrictions 7 87 ºF 77 ºF

With any DCT tube bundle isolated, at least 14 DCT fans and 7 WCT fans shall be

OPERABLE.

Enclosure Attachment 2 to W3F1-2018-0025 Proposed Technical Specification Changes (clean)

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7$5(2)/2'X 6.+5X X X X $-(.'-(.5X ./X!X X

TABLE 3.7-3 ULTIMATE HEAT SINK MINIMUM FAN REQUIREMENTS PER TRAIN (1)

ALLOWABLE FAN COMBINATIONS 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months / 3 day average dry bulb temperature restrictions OPERABLE DCT Fans OPERABLE 15 14 13 WCT Fans 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months 3 day 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months 3 day 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months 3 day 8 88 ºF 77 ºF No Temperature Restrictions 7 87 ºF 77 ºF

With any DCT tube bundle isolated, at least 14 DCT fans and 7 WCT fans shall be OPERABLE.

WATERFORD - UNIT 3 3/4 7-14 AMENDMENT NO. 95, 123, 139, 237

Enclosure Attachment 3 to W3F1-2018-0025 Revised List of Regulatory Commitments Attachment contains 1 page

Enclosure Attachment 3 to W3F1-2018-0025 Page 1 of 1 List of Regulatory Commitments This table identifies actions discussed in this letter for which Entergy commits to perform. Any other actions discussed in this submittal are described for the NRCs information and are not commitments.

TYPE (Check one) SCHEDULED COMPLETION COMMITMENT ONE- DATE CONTINUING TIME (If Required)

COMPLIANCE ACTION A UFSAR table will be added providing the X During maximum average dry bulb temperature implementation.

as a function of the time of year by month for 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , 3 day, and 7 day averages.

Enclosure Attachment 4 to W3F1-2018-0025 Graphical Results of Containment Pressure and Temperature Analysis with Peak Values (Excerpted from Waterford 3 UFSAR and Calculation ECS98-015)

Attachment contains 18 pages

54.9 psia 44 psia Revision 307 (07/13)

CONTAINMENT PRESSURE HOT Waterford Steam FIGURE LEG BREAK - 19.24 FT2 Electric Station #3 6.2-1m PEAK CONTAINMENT PRESSURE

Waterford 3 Calculation EC-S98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 40 of 80 Containment Pressure DEHLSB 60.00 54.9 psia 55.00 50.00 44 psia 45.00 40.00 35.00 P (psia) 30.00 25.00 20.00 15.00 10.00 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

Waterford 3 Calculation ECS98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 72 of 80 Containment Pressure DEHLSB - With Uncertainties 60 55.2 psia 55 50 45.5 psia 45 40 P (psia) 35 30 25 20 15 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

54.9 psia 44 psia

262.7F 242F 210F 188F Revision 307 (07/13)

CONTAINMENT VAPOR AND SUMP Waterford Steam FIGURE TEMPERATURE Electric Station #3 6.2-1n HOT LEG BREAK - 19.24 FT2

Waterford 3 Calculation EC-S98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 41 of 80 Containment Vapor and Liquid Temperature DEHLSB 262.7F 270.00 260.00 242F 250.00 Vapor Temp.

240.00 230.00 220.00 210F 210.00 200.00 188F 190.00 Sump T (F) Li T 170F 180.00 170.00 160.00 150.00 140.00 130.00 120.00 110.00 100.00 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

Waterford 3 Calculation ECS98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 73 of 80 Containment Vapor and Sump Liquid Temperature DEHLSB With Uncertainties 263.4F 265 255 245F Vapor Temp.

245 235 225 212F 215 205 190F 195 Liquid Temp.

T (F) 185 190F 175 165 155 145 135 125 115 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

262.7F 240F 210F 188F

51.8 psia 51.5 psia 49 psia 47 psia Revision 307 (07/13)

CONTAINMENT PRESSURE Waterford Steam FIGURE DISCHARGE LEG BREAK - 9.82 FT2 Electric Station #3 6.2-1p PEAK CONT. PRESSURE AT 24 HOURS

Waterford 3 Calculation ECS98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 49 of 80 Containment Pressure DEDLSB 55 51.8 psia 51.5 psia 49 psia 50 47 psia 45 40 35 P (psia) 30 25 20 15 10 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

Waterford 3 Calculation ECS98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 70 of 80 Containment Pressure DEDLSB - With Uncertainties 53 psia 55.0000 52 psia 51 psia 48.5 psia 50.0000 45.0000 40.0000 35.0000 P (psia) 30.0000 25.0000 20.0000 15.0000 10.0000 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

50.2 psia 51.8 psia 49 psia 47 psia

51.8 psia 51.2 psia 49 psia 47 psia

257 F 257.3 F 252F 247F 216F 205F 196F Revision 307 (07/13)

CONTAINMENT VAPOR AND SUMP Waterford Steam FIGURE TEMPERATURE Electric Station #3 6.2-1q DISCHARGE LEG BREAK - 9.82 FT2

Waterford 3 Calculation ECS98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 50 of 80 Containment Vapor and Sump Liquid Temperature DEDLSB 265 257 F 257.3 F 252F 255 247F 245 Vapor Temp.

235 225 216F 215 205F 205 Liquid Temp.

195 T (F) 185 196F 175 165 155 145 135 125 115 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

Waterford 3 Calculation ECS98-015 Containment P&T Response Analysis - Steam Generator Replacement Project Page 71 of 80 Containment Vapor and Sump Liquid Temperature DEDLSB With Uncertainties 260 F 265.0000 257 F 255F 251F 255.0000 245.0000 Vapor Temp.

235.0000 218F 225.0000 215.0000 205F 205.0000 Liquid Temp.

195.0000 T (F) 200F 185.0000 175.0000 165.0000 155.0000 145.0000 135.0000 125.0000 115.0000 0.01 0.10 1.00 10.00 100.00 1000.00 10000.00 100000.00 Time (sec)

257F 257.3F 247F 216F 205F 196F

255F 257.3F 247F 216F 205F

Enclosure Attachment 5 to W3F1-2018-0025 ECM95-008 Revision 3 (EC52043), Ultimate Heat Sink Design Basis Attachment contains 119 pages

ATTACHMENT 9.2 ENGINEERING CALCULATION COVER PAGE ANO-1 ANO-2 GGNS IP-2 IP-3 PLP JAF PNPS RBS VY W3 NP-GGNS-3 NP-RBS-3 (1) (2)

CALCULATION EC # 52043 Page 1 of 671 COVER PAGE (3) Design Basis Calc. YES NO (4) CALCULATION EC Markup (5 ) (6)

Calculation No: ECM95-008 Revision: 3 (7) (8)

Title:

Ultimate Heat Sink Design Basis Editorial YES NO (9) (10)

System(s): ACC, CC Review Org (Department): DESMECH (11) (12)

Safety Class: Component/Equipment/Structure Type/Number:

Safety / Quality Related ACCMTWR0001 A, Wet Cooling Tower A Augmented Quality Program ACCMTWR0001 B, Wet Cooling Tower B Non-Safety Related CC MTWR0001 A, Dry Cooling Tower A (13)

Document Type: B13.18 CC MTWR0001 B, Dry Cooling Tower B (14)

Keywords (Description/Topical CC MHX0001 A, CCW Heat Exchanger A Codes):

CC MHX0001 B, CCW Heat Exchanger B Ultimate Heat Sink, UHS, ACCW, ACCMVAAA126 A, ACC Header A CCW HX Outlet CCW, WCT, DCT, Cooling Tower, Temperature Control Valve Heat Exchanger ACCMVAAA126 B, ACC Header B CCW HX Outlet Temperature Control Valve REVIEWS (15) (16) (17)

Name/Signature/Date Name/Signature/Date Name/Signature/Date Dale Gallodoro Alex Tojeiro Nicholas Petit See Associated EC See Associated EC See Associated EC Responsible Engineer Design Verifier Supervisor/Approval Reviewer Comments Attached Comments Attached

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 2 OF 119 ATTACHMENT 9.3 CALCULATION REFERENCE SHEET CALCULATION CALCULATION NO: ECM95-008 REFERENCE SHEET REVISION: 3 I. EC Markups Incorporated (N/A to NP calculations)

II. Relationships: Sht Rev Input Output Impact Tracking Doc Doc Y/N No.

1-B 1 006 ;

2-D 1 002 ;

5-A 1 005 ; ; Y EC-52043 5-B 1 005 ; ; Y EC-52043 5-C 1 005 ; ; Y EC-52043 5-T 1 007 ; ; Y EC-52043 9C2-5Y 1 001 ;

1564.75 0 009 ; ; Y EC-52043 1564.86 0 008 ; ; Y EC-52043 1564.114A 0 010 ; ; Y EC-52043 1564.116 0 006 ; ; Y EC-68240 1564.260 0 015 ; ; Y EC-52043 1564.745 0 008 ; ; Y EC-52043 1564-1998 0 009 ; ; Y EC-52043 1564-2002 0 017 ; ; Y EC-52043 1564-6182 0 004 ;

1564-7934 0 003 ; ; Y EC-52043 5817-660 0 010 ;

5817-661 0 008 ;

5817-690 0 007 ;

5817-698 0 008 ;

5817-8938 1 001 ;

5817-9376 0 003 ; ; Y EC-52043 5817-9518 0 008 ; ; Y EC-52043 5817-9519 0 014 ;

5817-10743 0 001 ;

5817-10744 0 000 ;

5817-10745 0 000 ;

5817-10746 0 007 ;

5817-10747 0 000 ;

5817-10748 0 000 ;

5817-10749 0 000 ;

5817-10750 0 000 ;

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 3 OF 119 5817-10751 0 007 ;

5817-14476 0 000 ; ; Y EC-52043 5817-14480 0 000 ; ; Y EC-52043 5817-14487 0 000 ; ; Y EC-52043 5817-14488 0 000 ; ; Y EC-52043 5817-14291 0 000 ; ; Y EC-52043 5817-14296 0 000 ; ; Y EC-52043 457000087 0 005 ;

457001250 1 015 ;

457002178 0 000 ;

B425 T7075A1 003 ;

B425 T7075B1 003 ;

B425 T7077A 003 ;

B425 T7077B 004 ;

A15503-C-001 1 000 ; ; Y EC-52043 CN-OA-06-5 1 000 ;

CN-OA-08-50 1 001 ;

CN-SCC-16-007 1 000 ; ; Y EC-52043 CN-SEE-04-28 1 004 ; ;

CN-SEE-II-08-6 1 001 ; ; Y EC-52043 CN-SEE-II-09-21 1 001 ;

CN-SEE-III-08-49 1 000 ; ;

CN-TAS-03-30 1 005 ;

DAR-PS-03-8 1 002 ;

ECC98-015 1 000 ;

ECE90-006 1 008 ; ; Y EC-52043 ECI01-003 1 000 ;

ECI01-010 1 001 ; ; Y EC-52043 ECI01-002 1 001 ;

ECI91-003 1 002 ;

ECI91-005 1 001 ; ; Y EC-52043 ECI91-014 1 001 ;

ECI91-029 1 003 ; ; Y EC-52043 ECI91-036 1 001 ; ; Y EC-52043 ECI91-037 1 004 ; ; Y EC-52043 ECI91-046 1 001 ;

ECI92-002 1 001 ;

ECI95-004 1 001 ;

ECI97-001 1 001 ;

ECI08-001 1 000 ;

ECM03-002 1 000 ; ; Y EC-52043 ECM03-007 1 000 ;

ECM06-002 0 001 ; ; Y EC-52043 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 4 OF 119 ECM07-002 0 000 ; ; Y EC-52043 ECM11-002 1 003 ; ; Y EC-52043 ECM89-004 1 004 ;

ECM92-049 1 001 ;

ECM94-005 1 001 ;

ECM95-009 1 002 ; ; Y EC-52043 ECM95-012 1 004 ; ; Y EC-52043 ECM96-013 1 000 ;

ECM97-001 1 000 ;

ECM97-006 1 001 ; ; Y EC-52043 ECM97-022 1 000 ; ; Y EC-52043 ECM97-028 1 000 ; ; Y EC-68240 ECM98-010 1 000 ; ; Y EC-52043 ECM98-067 1 001 ; ; Y EC-52043 ECS05-013 1 001 ; ; Y EC-52043 ECS09-005 1 001 ;

ECS96-003 1 000 ; ; Y EC-52043 ECS96-015 1 000 ;

ECS98-013 1 000 ;

ECS98-015 1 002 ;

EN-ME-S-001-W 0 001 ; ; Y EC-52043 EP-002-100 0 042 ; ; Y EC-52043 FSAR Chapter 2 0 308 ; ; Y EC-52043 FSAR Chapter 3 0 308 ; ; Y EC-52043 FSAR Chapter 9 0 308 ; ; Y EC-52043 G160 1 049 ;

G160 2 050 ;

G160 3 032 ;

G160 4 017 ;

G160 5 019 ;

G160 6 014 ;

G210 0 020 ; ; Y EC-52043 G211 0 011 ; ; Y EC-52043 G212 0 002 ; ; Y EC-52043 G707 1 003 ; ; Y EC-52043 MNQ9-1 1 000 ; ; Y EC-52043 MNQ9-2 1 001 ; ; Y EC-52043 MNQ9-3 1 003 ; ; Y EC-52043 MNQ9-9 1 005 ; ; Y EC-52043 MNQ9-10 1 002 ; ; Y EC-52043 MNQ9-17 1 003 ; ; Y EC-52043 MNQ9-33 1 001 ;

MNQ9-38 1 004 ; ; Y EC-52043 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 5 OF 119 MNQ9-50 1 002 ; ; Y EC-52043 MNQ9-52 1 002 ;

MNQ9-53 1 001 ;

MNQ9-65 1 002 ; ; Y EC-52043 OP-002-001 0 309 ; ; Y EC-52043 OP-002-003 0 313 ; ; Y EC-52043 OP-002-004 0 312 ;

OP-002-006 0 316 ;

OP-009-002 0 324 ;

OP-009-005 0 035 ;

OP-100-014 0 325 ; ; Y EC-52043 OP-901-510 0 303 ;

OP-901-513 0 020 ;

OP-902-002 0 018 ;

OP-902-003 0 008 ;

OP-902-006 0 015 ;

OP-902-008 0 022 ;

OP-902-009 0 309 ;

PE-004-021 0 004 ;

PE-004-024 0 304 ;

PE-004-033 0 306 ;

RF-005-001 0 316 ; ; Y EC-52043 SD-CC 0 021 ; ; Y EC-52043 TD-A545.0015 0 000 ;

TD-B015.0025 0 004 ; ; Y EC-68240 TD-C629.0015 0 013 ; ; Y EC-52043 TD-H291.0015 0 000 ; ; Y EC-52043 TD-Z010.0015 0 000 ; ; Y EC-52043 TD-Z010.0025 0 002 ; ; Y EC-52043 Technical Specifications 0 330 ; ; Y EC-52043 Technical Specifications Bases 0 080 ; ; Y EC-52043 W3-DBD-1 0 304 ;

W3-DBD-2 0 303 ; ; Y EC-52043 W3-DBD-3 0 301 ; ; Y EC-52043 W3-DBD-4 0 303 ; ; Y EC-52043 W3-DBD-13 0 302 ; ; Y EC-52043 W3-DBD-23 0 300 ; ; Y EC-52043 W3-DBD-37 0 300 ;

WF3-ME-15-00011 0 000 ; ; Y EC-52043 WF3-ME-15-00012 0 000 ; ; Y EC-52043 WF3-ME-15-00013 0 000 ; ; Y EC-52043 WF3-ME-15-00014 0 000 ; ; Y EC-52043 WF3-ME-15-00015 0 000 ; ; Y EC-52043 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 6 OF 119 WF3-ME-15-00016 0 000 ; ; Y EC-52043 WF3-ME-16-00001 0 000 ; ; Y EC-52043 WF3-ME-16-00011 0 000 ; ; Y EC-52043 III. CROSS

REFERENCES:

10CFR50 Appendix A, General Design Criteria ASHREA Systems and Equipment Handbook, 1992, Pages 37.1 and 37.2 ASHREA Fundamentals Handbook, 2001 ATC-105, Acceptance Test Code for Water Cooling Towers, Cooling Tower Institute, February 2000 C-CE-135 (CDCC28717), Balance of Plant Design Criteria C-CE-9709 (CDCC60207), FSAR Update CCE-2559, letter from A.L. Gaines [CE] to R.K. Stampley [Ebasco],

Subject:

CCW Requirement for Equipment in CEs Scope, dated 10/9/75 CCE-3328, letter from W.D. Mawhinney [CE] to R.K. Stampley [Ebasco],

Subject:

RCP CCW Requirements, dated 7/16/76 (CDCC82603)

CCE-9709, letter from R.P. ONeill [CE] to R. Burski[LP&L],

Subject:

FSAR Update, dated 9/18/87 C-CE-135, Combustion Engineering Balance of Plant Design Criteria (CDCC28717)

CR-WF3-2012-1395, Wet Cooling Tower Fan Requirements CR-WF3-2012-2332, Cooling Tower Recirculation Assumption CR-WF3-2012-2870, ACC-126A(B) Closing Capability Criteria CR-WF3-2012-3850, Wet Cooling Tower Cross-Connect Errors CR-WF3-2012-3855, MNQ9-10 Not Updated to Reflect New Tornado and New Fuel Pool Cooling Evaluations CR-WF3-2013-883, Damage to top of WCT Fill CR-WF3-2013-1106, Damage to top of WCT Fill CR-WF3-2014-2651, Recirculation Affecting Some DCT Fans More than Others Not Considered In Design EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 7 OF 119 CR-WF3-2015-421, DCT Tube Leak CR-WF3-2015-828, DCT Tube Bundle Isolation Valves Not Tested for Leakage CR-WF3-2015-1482, DCT Tube Bundle Isolation Valves Not Tested for Leakage CR-WF3-2015-2117, Design Assumptions Regarding Post Tornado Heat Loads Not Supported by Proceduralized Actions CR-WF3-2015-2503, Tornado Case in MNQ9-2 CCW Flow Analysis Does Not Use Degraded Pump Curve Dunn, W. E. and Sullivan, S. M., Method for Analysis of Ultimate Heat Sink Cooling Tower Performance, University of Illinois at Urbana-Champaign, April 1986 (ADAMS Accession No. ML12146A145 EC-52043, UHS Margin Restoration EPRI TR-107397, Service Water Heat Exchanger Testing Guidelines, 1998 EPRI 3002005337, Classical Heat Exchanger Analysis EPRI 3002005340, Service Water Heat Exchanger Testing Guidelines, 2015 ER-W3-2005-0019-000, Raise EFW Level Control Setpoints to Support Actions for Submergence of Steam Generator U-Tubes ES-LOU-1-76, Meteorological Conditions Following Tornado Passage, April 29, 1976 ES-LOU-87-77, Design Meteorological Data for Ultimate Heat Sink, July 18, 1977 ES-LOU-91-77, FSAR Table 2.3-2(a) - Ultimate Heat Sink Design Parameters, August 2, 1977 Kreith, Principles of Heat Transfer, International Textbook, 1965 MAI 406137, Calibrate CC ITE7075B / CC ITE7076B NUREG-0800, Standard Review Plan NUREG 0693, Analysis of Ultimate Heat Sink Cooling Ponds NUREG 0733, Analysis of Ultimate Heat Sink Spray Ponds PEIR OM-112, Post Accident Sampling System Operation Regulatory Guide 1.27, Ultimate Heat Sink for Nuclear Power Plants Taborek, J. Shell and Tube Heat Exchangers: Single Phase Flow, Heat Exchanger Design Handbook, Chapter 3.3, Hemisphere, NY, 1983 Wolverine Tube Company, Engineering Data Book III, J. Thome, 2004 WO 12709, Thermal Performance Test on WCT A WO 12724, Thermal Performance Test on WCT B WO 14176, Thermal Performance Test on WCT and CCW HX B WO 41082, Thermal Performance Test on Train B Wet Cooling Tower WO 144200, Thermal Performance Test on Train A Wet Cooling Tower WO 186585, Thermal Performance Test on CCW HX B WO 50576, CCW / ACCW Train A Flow Balance WO 247369, CCW / ACCW Train A Flow Balance WO 247374, CCW / ACCW Train B Flow Balance WO 52368665, CCW / ACCW Train A Flow Balance WO 52363706, CCW / ACCW Train B Flow Balance WO 52480812, Perform CC / ACC Train B Flow Balance per PE-004-024 WO 52476425, Perform CC / ACC Train A Flow Balance per PE-004-024 WO 99003470, ACCW Jockey Pump Post Modification Testing WO 74223, Fuel Pool Cooling Heat Exchanger Tube Sheet Inspection WO 00186585, Thermal Performance Test on WCT and CCW HX A EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 8 OF 119 WO 00012763, Thermal Performance Test on WCT and CCW HX B WO 52348919, Thermal Performance Test on Train B Wet Cooling Tower WO 52372443, Thermal Performance Test on Train A Wet Cooling Tower WO 50231938, Calibrate CC ITE7075A / CC ITE7076A Waterford 3 SES Wet Cooling Tower B Capability Summary Report, May 21, 1998, C&A Consulting Services and John Cooper & Associates Waterford 3 SES Wet Cooling Tower A Capability Summary Report, May 21, 1998, C&A Consulting Services and John Cooper & Associates W3I82-0146, Confirmatory Issue 2.4.5, Ultimate Heat Sink Testing, February 11, 1983 W3F1-98-0040, Request for Additional Information (RAI) Regarding Technical Specification Change Request NPF-38-193 IV. SOFTWARE USED:

Title:

Mathcad Version/Release: 14 Disk/CD No. N/A V. DISK/CDS INCLUDED:

Title:

N/A Version/Release N/A Disk/CD No. N/A VI. OTHER CHANGES:

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 9 OF 119 ATTACHMENT 9.4 RECORD OF REVISION Sheet 1 of 1 Revision Record of Revision 0 Initial issue.

Determine equivalent meteorological conditions that UHS can reject the 0-1 design basis heat load.

CR 97-0777 documented that the containment heat loads for the UHS did not contain certain conservative assumptions. The purpose of this calculation 0-2 change is to revise the UHS design bases requirements corresponding to maximum containment heat load rate determined by calculation MN(Q)-9-3.

This is a complete rewrite; therefore no revision bars are used.

Provides justification for use of hot air recirculation values and adds computation of the ACCW System design temperature in response to the recommended dispositions of Design Basis Review Open Items: OI-CCW-1 296-C and OI-CCW-297-C. Adds Keywords to Section 3. Replaces Reference 3.3 and removes references to the FSAR. Corrects typographical errors. This is a complete rewrite; therefore no revision bars are used.

Modified UHS Design Basis as a result of Total Heat Duty input changes at 3716 MWt. A methodology change was made in section 5.4 to ensure Tech Spec 3/4.7.4 compliance. Calculation and Attachment changes have been made accordingly. Added page 2 of 2 to Attachment 7.3 to include the regression analysis for the DCT. This analysis was referenced in section 6.1.1 DRN of the calculation. Section 6.6.4 was added to address Met tower conditions03-509 from Calculation ECM03-007. The basis for the heat load from emergency diesel generators and the LPSI/HPSI/CS pumps in circular. Calculation ECM95-008 references calculation MNQ9-3 for this heat load and MNQ9-3 references ECM95-008 for the same heat load. ECM95-008 now references Calculation MNQ9-65 which develops the basis for these heat loads.

DRN Added Assumption 4.7 to clarify that containment heat loads were determined 05-766 assuming 112°F CCW temperature (ECS01-005).

This revision incorporated all outstanding changes and DRNs. ECS05-013 was changed to the new input for containment heat loading and all 2

calculations were revised accordingly. CR-WF3-2005-0230 documented that the CCW flows used in the calc did not bound the As-Built flows determined EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 10 OF 119 during flow testing. The CCW accident flow has been increased to a bounding 6900 gpm.

Corrected transposition errors in paragraphs 5.3 and 5.4, math operator in paragraph 6.3.1, and copy and paste error in Attachment 7.1, identified on 3

CR-WF3-2007-1420. The errors did not affect the results of the calculation.

Therefore, this is an administrative change only.

Reconstitute the design basis for the Ultimate Heat Sink to resolve nonconforming conditions identified on CR-WF3-2012-1395, CR-WF3-2012-2332, CR-WF3-2012-2870, CR-WF3-2012-3850, CR-WF3-2012-3855, CR-WF3-2012-2651, CR-WF3-2015-828, CR-WF3-2015-1482, CR-WF3-2015-2117, and CR-WF3-2015-2503 and to consolidate calculations that use similar methodology and inputs for evaluating the capability of the UHS.

Modifications are authorized by EC-52043 to reduce recirculation. Additional studies were performed to establish bounding design basis controlling EC-parameters for the analysis. This calculation supersedes and replaces the 52043 following calculations: MNQ9-3, MNQ9-9, MNQ9-10, MNQ9-17, ECM95-009, ECM98-010, and parts of ECM98-067. This calculation markup will be as-built upon the successful installation of the child ECs associated with EC-52043 including installation of DCT recirculation barriers, raising CCW SIAS supply temperature setpoint to 117.4°F, and implementation of new cooling tower fan operability requirements in TS Table 3.7-3. This EC Markup supersedes the EC Markups for EC-8465 and EC-2918. Because this EC Markup is a complete rewrite, revision bars are not used.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 11 OF 119 Table of Contents 1.0 Purpose ....................................................................................................................................................................... 12 2.0 Conclusions ................................................................................................................................................................. 20 3.0 References .................................................................................................................................................................. 41 4.0 Input and Design Criteria ............................................................................................................................................. 53 5.0 Assumptions ............................................................................................................................................................... 85 6.0 Method of Analysis.................................................................................................................................................... 107 7.0 Calculations ............................................................................................................................................................... 116 8.0 Attachments ............................................................................................................................................................. 117 EFFECTIVE PAGES Rev. 3 EC-52043 - ALL EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 12 OF 119 1.0 Purpose 1.1 This calculation demonstrates that the Ultimate Heat Sink (UHS), which consists of the Dry Cooling Towers (DCT), Wet Cooling Towers (WCT), the Component Cooling Water (CCW) Heat Exchanger (HX), and the water stored in the WCT Basins, is capable of performing its design basis function with margin for the analyzed conditions listed below: [4.1] 1 1.1.1 Loss of Coolant Accident (LOCA) -

1.1.1.1 Demonstrate that the UHS is capable of dissipating the bounding design basis peak and long term LOCA heat loads under worst case design basis meteorological conditions, assuming a loss of offsite power (LOOP) and a worst case single active failure, while supplying:

x 120°F maximum cooling water to essential plant cooling loads, except for the Essential Chiller, for at least 30 days. [4.1.1, 4.4.1]

x 110°F maximum coolant to the Essential Chiller for at least 30 days.

[4.4.6]

1.1.1.1.1 Confirm that 120°F CCW supply temperature is adequate to maintain Emergency Diesel Generator (EDG) temperatures within manufacturer specified alarm limits given design basis bounding heat load and limiting HX flow rates during a LOCA.

1.1.1.1.2 Provide reference to other design basis calculations to show that 120°F CCW supply temperature is adequate to maintain design basis functions of other safety related equipment, namely Containment Fan Coolers (CFC), Shutdown Cooling (SDC) HX, Containment Spray (CS) pump, High Pressure Safety Injection (HPSI) Pump, Low Pressure Safety Injection (LPSI) pump, and Fuel Pool Cooling (FPC) given design basis bounding heat load and limiting HX flow rates during a LOCA.

1.1.1.1.3 Provide reference to other design basis calculations to show that 110°F coolant temperature is adequate to maintain design basis functions of the Essential Chiller during a LOCA.

1.1.1.2 Demonstrate that, of the analyzed LOCA events, the Reactor Coolant System (RCS) Cold Leg Reactor Coolant Pump (RCP) Discharge Break (Cold Leg Break), referred to in the safety analysis as the Double Ended Discharge Line Slot Break (DEDLSB) results in the highest valid peak heat load on the UHS and is therefore the appropriate LOCA for evaluating the overall capability of the UHS to remove the design basis containment heat load during a LOCA and for evaluating allowable CCW HX fouling and cooling tower fan and tube 1

References with hyperlinks are identified in brackets [ ].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 13 OF 119 bundle requirements. Demonstrate that, of the analyzed LOCA events, the DEDLSB also results in the highest integrated heat load on the UHS and is therefore the appropriate LOCA for evaluating water inventory margin.

1.1.1.3 Demonstrate that the failure of an EDG, which results in only one train of UHS available for the event, is the limiting malfunction for total water consumption including EFW and WCT evaporation and drift losses after a LOCA.

1.1.1.4 Determine the heat transfer capacity for the DCT, the CCW HX, and the WCT for dissipating the bounding design basis heat loads under design basis meteorological conditions while supplying design basis CCW temperature.

1.1.1.4.1 The results must confirm acceptability of the selected allowable CCW HX fouling and tube plugging limits.

1.1.1.4.2 The results must confirm the acceptability of the selected allowable DCT tube plugging and sleeving limits.

1.1.1.4.3 Provide a basis for reducing cooling tower fan requirements during periods of lower ambient temperature. Determine DCT and WCT fan requirements based on ambient temperature.

1.1.1.4.4 Provide a basis for isolating a DCT tube bundle for maintenance during periods of lower ambient temperature. Determine DCT tube bundle requirements based on ambient temperature.

1.1.1.4.5 Demonstrate the acceptability of the uncertainty or tolerance in cooling water temperature control.

1.1.1.5 Determine the WCT integrated heat load after a LBLOCA.

1.1.1.6 Provide a basis for the point in time after a LOCA when total plant heat load except for Essential Chillers can be dissipated with the DCT only supplying 117.4°F CCW, i.e. the time when decay heat lowers to the point where shutdown cooling load plus auxiliary loads would be less than the capacity of the DCT and ACCW flow to the CCW HX can be secured.

1.1.1.7 Provide a basis for the point in time after a LOCA when total plant heat load can be dissipated with the DCT only supplying 110°F CCW. This is when the Essential Chiller can be swapped back to Dry Tower mode.

1.1.1.8 Determine the design basis water inventory margin for the LOCA.

1.1.1.9 Identify any required administrative controls for managing water consumption and inventory after a LOCA.

1.1.1.9.1 Provide a basis for timing of operator manual local control of CCW temperature control valve ACC-126A(B) after a LOCA.

1.1.1.9.2 Provide a basis for timing of operator manual control of WCT fans after a LOCA.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 14 OF 119 1.1.1.9.3 Provide a basis for timing and throttling requirements for restoration of FPC after a design basis LOCA.

1.1.1.9.4 Provide a basis for other post-LOCA operator actions to preserve water inventory margin to ensure a 30 day mission time for the UHS.

1.1.1.10 Demonstrate that the UHS water consumption for a LBLOCA (DEDLSB) is bounding with respect to a worst case small break LOCA (SBLOCA) considering Emergency Feedwater (EFW) consumption required to reach SDC entry conditions and subsequent WCT evaporation.

1.1.2 Non-LOCA Type Accident 1.1.2.1 Demonstrate that the UHS is capable of dissipating the bounding design basis peak and long term Non-LOCA accident heat loads under worst case design basis meteorological conditions, assuming a loss of offsite power (LOOP) and a worst case single active failure, while supplying:

x 120°F maximum cooling water to essential plant cooling loads, except for the Essential Chiller, for at least 30 days. [4.1.1, 4.4.1]

x 110°F maximum coolant to the Essential Chiller for at least 30 days.

[4.4.6]

1.1.2.2 The event is referred to as Non-LOCA accident throughout the remainder of this calculation and in supporting calculations. A non-LOCA accident may not get a Safety Injection Actuation Signal (SIAS) and so would not get automatic isolation of the FPC HX or automatic raising of CCW supply temperature.

The capability to reach cold shutdown in a reasonable period (BTP 5-4) and to provide cooling for at least 30 days (RG 1.27) using only safety related equipment, assuming a LOOP and a worst case single active failure is evaluated in this calculation.

1.1.2.3 Demonstrate that, of the analyzed Non-LOCA accidents, one that reaches SDC entry conditions as early as possible results in the highest peak heat load and total integrated heat on the UHS and is therefore bounding for evaluating the overall capability of the UHS to remove the design basis containment heat load during a Non-LOCA accident and for evaluating CCW supply temperatures, water inventory margin, allowable CCW HX fouling, and cooling tower fan and tube bundle requirements.

1.1.2.4 Demonstrate that the stored water inventory in the WCT basins and the Condensate Storage Pool (CSP) is sufficient for cooling the RCS to cold shutdown (<200°F) and for cooling required auxiliaries and FPC for at least 30 days. [4.1.2]

1.1.2.5 Demonstrate that the failure of an EDG, which results in only one train of UHS available for the event, is the limiting malfunction for total water consumption including EFW and WCT evaporation and drift losses during a Non-LOCA EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 15 OF 119 accident.

1.1.2.6 Determine the limiting times to reach SDC entry conditions.

1.1.2.7 Determine the achievable RCS cool down rate and associated time to reach cold shutdown (200°F RCS temperature) that supports the selected CCW supply temperature with bounding design basis ambient temperatures and limiting cooling tower capacities.

1.1.2.8 Determine the heat transfer capacity for the DCT, the CCW HX, and the WCT for dissipating the design basis cool down heat loads under design basis meteorological conditions while supplying required CCW temperature.

1.1.2.9 Determine the WCT integrated heat load during a Non-LOCA accident.

1.1.2.10 Determine the design basis water inventory margin for the bounding Non-LOCA accident, considering WCT inventory credited for EFW and Technical Specification (TS) UHS fan requirements.

1.1.2.11 Identify any required administrative controls for managing water consumption, cooling water temperatures, and heat load on the UHS during a bounding Non-LOCA accident cooldown.

1.1.2.11.1Provide a basis for timing of operator manual control of CCW supply temperature and local control of CCW temperature control valve ACC-126A(B) after a Non-LOCA accident.

1.1.2.11.2Provide a basis for timing of operator manual control of WCT fans after a LOCA.

1.1.2.11.3Provide a basis for timing and throttling requirements for manual isolation and restoration of FPC after a design basis LOCA.

1.1.2.11.4Provide a basis for other post-LOCA operator actions to preserve water inventory margin to ensure a 30 day mission time for the UHS.

1.1.3 Design Basis Tornado Coping Strategy and Water Requirements 1.1.3.1 Demonstrate that the missile protected parts of the UHS, assuming a LOOP and a worst case single failure, can dissipate the bounding design basis tornado event heat loads while supplying:

x 120°F maximum CCW supply temperature throughout the event.

[4.1.3]

x 110°F maximum coolant to the Essential Chiller throughout the event.

[4.4.6]

1.1.3.1.1 Confirm that 120°F CCW supply temperature is adequate to maintain EDG temperatures within manufacturer specified alarm limits given design basis bounding heat load and limiting HX flow rates after a design basis tornado.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 16 OF 119 1.1.3.1.2 Provide reference to other design basis calculations to show that 120°F CCW supply temperature is adequate to maintain design basis functions of other safety related equipment, namely CFC, SDC HX, CS pump, HPSI Pump, LPSI pump, and FPC given design basis bounding heat load and limiting HX flow rates after a design basis tornado.

1.1.3.1.3 Provide reference to other design basis calculations to show that 110°F coolant temperature is adequate to maintain design basis functions of the Essential Chiller after a design basis tornado.

1.1.3.2 Determine the heat transfer capacity for the missile protected parts of the UHS (60% DCT, the CCW HX, and the WCT on natural draft) at various times during the implementation of the tornado coping strategy.

1.1.3.2.1 The results must confirm acceptability of the selected allowable CCW HX fouling and tube plugging limits.

1.1.3.2.2 The results must confirm the acceptability of the selected allowable DCT tube plugging and sleeving limits.

1.1.3.2.3 Demonstrate the acceptability of the uncertainty or tolerance in cooling water temperature control.

1.1.3.3 Provide a basis for the point in time after a design basis tornado when SDC can be initiated and EFW consumption ends, i.e. the time when total plant heat load matches UHS capacity.

1.1.3.4 Provide a basis for the point in time after a design basis tornado when SDC can be entered and EFW consumption can be stopped. i.e. Determine the time when decay heat lowers to the point where shutdown cooling plus auxiliary loads plus FPC load is less than or equal to the capacity of 60% the DCT and WCT on natural draft with supply temperature of less than 120°F.

Demonstrate that WCT basin outlet temperature does not exceed Essential Chiller cooling water limit of 110°F.

1.1.3.5 Identify any required administrative controls for managing water consumption and inventory after a design basis tornado.

1.1.3.5.1 Provide a basis for timing of operator manual restoration of undamaged DCT tube bundles.

1.1.3.5.2 Provide a basis for timing of operator manual local control of CCW temperature control valve ACC-126A(B) after a design basis tornado.

1.1.3.5.3 Provide a basis for timing and throttling requirements for restoration of FPC after a design basis tornado.

1.1.3.5.4 Demonstrate that the credited water inventory and credited water replenishment procedures can supply the required EFW system makeup and maintain required WCT basin inventory throughout the tornado event.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 17 OF 119 1.1.3.5.5 Demonstrate that the credited replenishment accounts for potential leakage past the unprotected DCT tube bundle isolation valves.

1.1.3.6 Provide a basis for the point in time after a design basis tornado when the total plant heat load can be dissipated with the missile protected parts of the DCT only. i.e. Determine the time when decay heat lowers to the point where SDC load plus auxiliary loads plus FPC load plus Essential Chiller load is less than or equal to the capacity of the missile protected parts of the DCT with outlet temperature less than or equal to 110°F. This is the time when the Essential Chiller can be swapped back to Dry Tower mode.

1.1.4 Spent Fuel Pool Cooling, including Core Offload - Based on inputs from ECM98-067

[3.1.1.45]:

1.1.4.1 Demonstrate the ability of the UHS and FPC system, assuming administrative controls to limit the commencement and rate of fuel movement, to keep fuel pool bulk temperature below 140°F for the normal maximum heat load, which is a partial core discharge or a full core discharge during a refueling outage.

The normal maximum heat load analysis considers a single active failure consisting of a failure of a divisional electrical bus which renders only one CCW pump and one FPC pump available. [4.1.4]

1.1.4.1.1 Consider one train of CCW with one operating pump and one operating electrical bus, one operating EDG, one Essential Chiller, and one LPSI pump with bounding FPC HX load and limiting Fuel Pool bulk temperature.

1.1.4.1.2 Determine the required CCW supply temperature for the FPC system with only one FPC pump available to be able to keep the bulk fuel pool temperature below 140°F with bounding Fuel Pool heat.

1.1.4.1.3 Determine the heat transfer capacity for the DCT, the CCW HX, and the WCT for dissipating the bounding core offload heat loads under seasonal meteorological conditions while supplying required CCW temperature to maintain fuel pool temperature with limits.

1.1.4.1.4 Determine the required fuel movement delay time after shutdown for ambient conditions during typical core offload ambient weather conditions such that fuel pool heat cannot exceed the capacity of the UHS to maintain Fuel Pool temperature below limits.

1.1.4.2 Demonstrate the ability of the FPC system to keep fuel pool bulk temperature below boiling for the abnormal maximum heat load, which is a full core discharge subcritical for 150 hours0.00174 days 0.0417 hours 2.480159e-4 weeks 5.7075e-5 months and the previous discharged fuel stored for 36 days since the previous shutdown. A concurrent single failure is not required to be considered for this condition. [4.1.4]

1.1.4.3 Provide guidance for performing cycle specific evaluations to allow one time changes to administrative controls, such as in-reactor hold time limits or time of year restrictions based on realistic fouling factors, weather forecasts, etc.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 18 OF 119 1.1.5 Normal Operations, Normal Shutdown, and Normal Refueling -

1.1.5.1 Demonstrate that the UHS is capable of dissipating heat removed from the reactor and its auxiliaries while the CCW system supplies desired cooling water temperatures for removing heat from the safety related and non-safety related auxiliaries during normal operations, normal shutdown, and normal refueling.

1.1.5.2 Determine the heat transfer capacity for the DCT, the CCW HX, and the WCT for dissipating the normal heat loads during a normal operations, shutdown, and refueling, under extreme meteorological conditions while supplying normal CCW temperature.

1.1.5.3 Determine maximum allowable CCW HX fouling factor for normal operation, normal shutdown, and normal refueling.

1.2 ACC-126A(B) Throttling Function Criteria 1.2.1 Clarify the design basis throttling requirement for ACC-126A(B), CCW Supply Header Temperature Control Valve.

1.2.2 Establish acceptance criteria for demonstrating that ACC-126A(B) is capable of closing adequately to protect assumptions used in determining the WCT basin inventory margin after an accident.

1.3 Auxiliary Component Cooling Water (ACCW) Pump Transient Horsepower 1.3.1 Provide a basis for the bounding 7 day average brake horsepower for the ACCW Pumps during a LOCA to be used in the EDG Fuel Oil Consumption calculation.

[3.1.1.15]

1.4 Thermal Performance Test Evaluation Templates 1.4.1 Provide templates for evaluating the periodic thermal performance tests of the WCT and CCW HX.

1.5 License Basis Documents - Provide the basis for the following license basis documents: [3.1.5.8, 3.1.5.1]

1.5.1 FSAR Figure 9.2-4, Heat Load Dissipation of UHS after LOCA 1.5.2 FSAR Figure 9.2-4a, Wet Cooling Tower Integrated Heat Load Curve After LOCA.

1.5.3 FSAR Figure 9.2-5, Heat Removal Capacity of Dry Cooling Tower vs. Dry Bulb Temperature 1.5.4 FSAR Figure 9.2-5a, Ultimate Heat Sink Design Basis Meteorological Conditions.

1.5.5 FSAR Table 9.2-3, Heat Removal and Water Requirements for the CCWS.

1.5.6 FSAR Table 9.2-9, Estimated Wet-Dry Cooling Tower Heat Dissipation for All EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 19 OF 119 Operations.

1.5.7 FSAR Table 9.2-10, Water Requirements for Wet Cooling Towers Post LOCA Essential Heat Loads 1.5.8 Technical Specification (TS) table 3.7-3, Ultimate Heat Sink Minimum Fan Requirements per Train.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 20 OF 119 2.0 Conclusions 2.1 The analyses documented herein demonstrates that the UHS is capable of performing its design basis function with adequate margin for the following analyzed conditions:

[1.1]

2.1.1 LOCA:

2.1.1.1 Bounding Analysis 2.1.1.1.1 The analysis demonstrates that the UHS is capable of dissipating the peak heat load while supplying 120°F (analysis limit) cooling water to essential plant components (110°F to Essential Chillers) under worst case meteorological conditions (102°F dry bulb, 78°F wet bulb) in the event of a design basis LOCA concurrent with a Loss of Offsite Power (LOOP) and a worst case single failure. [8.1]

2.1.1.1.1.1 The analysis confirms that 120°F CCW supply temperature is adequate to maintain all safety related equipment within design basis temperature limits. [8.7.1] Calculation 5-T [3.1.1.6]

concludes that 110°F coolant temperature is adequate to support design basis performance of the Essential Chiller. [8.7.1]

2.1.1.1.2 The DEDLSB results in the highest valid peak heat load and highest integrated heat load on the UHS and is therefore the appropriate LOCA for evaluating peak heat load on the UHS to determine allowable CCW HX fouling, cooling tower fan and tube bundle requirements, and water inventory margin. [1.1.1.2, 4.3.5.1, 5.1.6]

2.1.1.1.2.1 The analysis concludes that the highest valid containment heat load that needs to be dissipated to the environment by the UHS for the LOCA is 142.25 x 106 BTU/hr at 54.25 minutes after the LOCA.

[4.3.5.1, 8.1]

2.1.1.1.3 The analysis is performed for a variety of anticipated ambient conditions with appropriate combinations of dry bulb temperature, bounding coincident wet bulb temperature, wind speed, recirculation, and fan performance. Attachment series [8.1] provides the results of the UHS LOCA analyses.

2.1.1.1.4 The heat transfer capacity for the DCT, the CCW HX, and the WCT for dissipating the bounding design basis heat loads under design basis bounding one hour critical time period meteorological conditions with all fans while supplying design basis CCW temperature is shown in the following table:

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 21 OF 119 Design Parameter Value Dry Bulb Temperature (Tdb) 102°F [4.2.1]

Coincident Wet Bulb Temperature (Twb) 78°F [4.2.1]

Recirculation Effects 2 0.2°Fdb 8.8°Fwb [4.6.2.7, 4.6.4.5]

CCW HX CCW Outlet Temperature Set 117.4°F [8.1]

CCW Flow Rate 6900 gpm [4.4.1]

6 Peak Containment Heat Load 140.34 x 10 BTU/hr [4.3.5.1]

6 Auxiliary Heat Load 9.75 x 10 BTU/hr [4.3.2]

Peak Heat Load less Essential Chiller 150.09 x 106 BTU/hr [8.1]

6 Essential Chiller Heat Load 4.3 x 10 BTU/hr [4.3.3]

6 Peak Heat Load with Essential Chiller 154.39 x 10 BTU/hr [8.1]

DCT CCW Inlet Temperature 161.6°F [8.1]

DCT Range 32.64°F [8.1]

6 DCT Heat Removal 111 x 10 BTU/hr [8.1]

DCT CCW Outlet Temperature / CCW HX 128.96 °F [8.1]

CCW Inlet Temperature DCT Allowable Tube Plugging 80 tubes (2.4%) [5.7.3.2]

DCT Allowable Tube Sleeving 2772 tubes (82.5%) [5.7.3.3]

ACCW Flow Rate 5,350 gpm max [0]

6 CCW HX Heat Removal 39.5 x 10 BTU/hr [8.1]

CCW HX ACCW Inlet Temperature 88.96°F [8.1]

CCW HX Allowable Fouling Factor 0.0012 hr ft2 °F / BTU [5.7.5]

CCW HX Allowable Tube Plugging 63 tubes (5%) [5.7.5]

CCW HX ACCW Outlet Temperature 121.14°F [8.1]

Essential Chiller Outlet Temperature 99.15°F [8.1]

6 WCT Heat Removal 43.8 x 10 BTU/hr [8.1]

WCT Cooling Range 26.55°F [8.1]

WCT Approach 10.96°F [8.1]

2 The recirculation effect is the difference between remote ambient temperature and the temperature at the inlet of the cooling tower, due to hot air recirculating from the tower exhaust. EC-52043 installs new DCT Recirculation Barriers (DCTRB) as an improvement to resolve CR-WF3-2012-2332, which identified non-conservative assumptions in the original design analysis regarding recirculation. Recirculation effect varies with wind which is related to ambient temperature. The recirculation effect shown here is for bounding high dry bulb temperature where there is no wind.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 22 OF 119 See [2.1.1.5] for discussion of margin and conservatism.

2.1.1.1.5 The analysis demonstrates that the UHS is capable of dissipating the total plant heat load for at least 30 days under bounding meteorological conditions (3 day average 89°F dry bulb, 76°F wet bulb, and 58% Relative Humidity (RH)) after a design basis LOCA concurrent with a LOOP and a worst case single failure. [4.2, 8.1]

2.1.1.1.6 The charts in attachment series [8.1] illustrate the analysis timeline for the limiting LOCA Long Term Cooling analysis. [8.1]

2.1.1.1.7 The heat transfer capacity of the DCT, the CCW HX, and the WCT for dissipating the bounding long term heat loads under design basis meteorological conditions while supplying design basis CCW temperature is shown on attachment series [8.1].

2.1.1.1.7.1 The allowable CCW HX fouling factor is 0.0012 hr ft2 °F / BTU.

[5.7.5]

2.1.1.1.7.2 The allowable CCW HX tube plugging is 63 tubes or 5%. [5.7.5]

2.1.1.1.7.3 The allowable DCT Tube plugging is 80 tubes or 2.4%. [5.7.3.2]

2.1.1.1.7.4 An equivalent number of DCT Tube sleeves may be installed accounting for the ratio of 42.6 tube sleeves to 1 tube plug for heat transfer impact and 16.5 tube sleeves to 1 tube plug for pressure drop impact. Based on the more limiting pressure drop impact, up to 2772 tube sleeves are allowed (5%

16.5:1 = 82.5% (2772)). A 2.4% plug limit is assumed for heat transfer performance, which would allow all tubes to be sleeved if no tubes were plugged (2.4%

x 42.6:1 = 100%). The table in section [5.7.3.4] provides additional guidance. Engineering Standard EN-ME-S-001-W [3.2.2.13] is updated to show sleeving limits.

2.1.1.1.8 Water inventory margin (all fans operable): [8.1]

2.1.1.1.8.1 The table below shows the total water consumption from the WCT Basins for the LBLOCA Event with all fans and bounding three day average ambient conditions.

Event Consumed, Margin, gallons gallons 1 basin / 2 basins LBLOCA w FPC 85,500 88,500 / 246,000 LBLOCA wo FPC 44,400 129,600 / 287,000 2.1.1.1.8.2 The water consumption is analyzed for a failed EDG. The failed EDG is the limiting failure for water consumption because it results in only one DCT in operation.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 23 OF 119 2.1.1.1.8.2.1 Note that the LBLOCA analysis does not credit EFW for cooling and there are no established procedures for transferring water from the CSP to the WCT basins. Therefore, the volume of water in the CSP is not credited for use by the UHS for the LBLOCA.

2.1.1.2 Reduced Fan / Tube Bundle Requirements Based on Ambient Dry Bulb Temperature 2.1.1.2.1 Study cases confirmed that the UHS capacity margin is adequate to compensate for out-of-service fans and an isolated DCT tube bundle with certain ambient temperature restrictions. See Attachment 8.1 for details.

[8.1]

2.1.1.2.1.1 The table below summarizes the CCW supply temperature margin with various fans out of service (covered to prevent backflow (DCTFBP) and uncovered). Details are in attachment [8.1].

Meteorological parameters established per section [4.2] are used.

LBLOCA with Supply Analysis Limit for 1 Hour SFP cooling Temperature Ambient Dry Bulb Margin, °F Temperature 15 fans operable 2.6 102 °F [8.1] bounding If at least 7 WCT fans are operable.

14 fans operable 2.2 102 °F [8.1] bounding 1 inop DCTFBP If at least 7 WCT fans are operable.

14 fans operable 1.25 102 °F [8.1] bounding 1 inop uncovered If at least 7 WCT fans are operable.

13 fans operable 0.75 102 °F [8.1] bounding 2 inop DCTFBP If at least 7 WCT fans are operable.

13 fans operable 0.25 88 °F [8.1] high exceeds 5/12 of year 2 inop uncovered If all 8 WCT fans are operable.

12 fans operable 0.16 89 °F [8.1] high exceeds 4/12 of year 3 inop DCTFBP If all 8 WCT fans are operable.

2.1.1.2.1.2 Inoperable WCT Fans must be covered to prevent short cycling of air flow or the entire WCT must be considered inoperable.

2.1.1.2.1.3 The UHS must be able to provide coolant at the required temperature and must also last for at least 30 days. Therefore, water inventory margin will be considered below and the most EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 24 OF 119 limiting fan requirements must be used.

2.1.1.2.2 Study cases confirmed that the water inventory margin is adequate to compensate for out-of-service fans and an isolated tube bundle. See attachment series 8.1 for details. [8.1]

2.1.1.2.2.1 The table below summarizes the water inventory margin with various fans out of service (covered to prevent backflow and uncovered). The analysis is detailed in attachment [8.1] based on meteorological parameters established per section [4.2].

LBLOCA with Inventory Margin, Analysis Limit for 3 Day SFP cooling gallons Average Temperature 15 fans operable 246,124 89 °F [8.1] Bounding 14 fans operable 156,624 89 °F [8.1] Bounding 1 inop DCTFBP 14 fans operable 67,624 89 °F [8.1] Bounding 1 inop uncovered 13 fans operable 31,624 89 °F [8.1] Bounding 2 inop DCTFBP 13 fans operable 20,624 78 °F [8.1]

2 inop uncovered High exceeds in late April - early October 12 fans operable 37,624 79 °F [8.1]

3 inop DCTFBP High exceeds in late April - early October 12 fans operable -100,000 74 °F [8.1]

3 inop uncovered High exceeds in March - November 12 fans with 3 uncovered is shown for information only. Results are not acceptable for expected high 3 day average temperature at any time of year.

2.1.1.2.2.2 The water inventory margin is based on a temperature control valve uncertainty of +/- 2.6°F in accordance with calculation ECI91-036

[3.1.1.27] and ECI01-010 [3.1.1.21]. The lower uncertainty will be reduced to account for containment heat load uncertainty that is built into the results of ECS05-013 [3.1.1.46]. The upper bound decay heat fractions are used to determine the containment heat load, which adds more than 5.5% to the heat load for the entire transient. Attachment [8.1.8] and section [4.4.4.1.3] concludes that the CCW setpoint tolerance should be considered only 1.1°F if the EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 25 OF 119 entire uncertainty is taken for the containment heat loads. This is equivalent to using the square-root-of-the-sum-of-the-squares (SRSS) method of combining uncertainties. The analysis considers that the CCW HX outlet temperature may be as low as 116.3°F.

Lower CCW HX outlet temperature results lower temperature differentials and less heat dissipation by the DCT and more water consumption by the WCT.

2.1.1.2.2.3 The DCT fan requirements for water inventory margin are valid if at least 7 WCT fans are operable. A study documented in attachment series [8.1] to demonstrate that water consumption for the event is not significantly impacted by the number of WCT fans out of service. The water consumption totals for 7 WCT fans are all within 5,000 gallons of the water consumption with 8 WCT fans.

This is well within the minimum design inventory margin for each DCT fan requirement analysis limit.

2.1.1.2.2.4 Fan requirements are established based on the most restrictive results for CCW supply temperature margin based on 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months ambient dry bulb temperature and water inventory margin based on three day average ambient dry bulb temperature. The water consumption analysis is based on bounding three day average temperature. Three day average temperature forecast are considered more reliable than seven day forecasts. In addition, the plant heat loads for the first three days of any event would be significantly higher than the remainder of the event. Therefore, it is appropriate to base fan requirements on the current one hour ambient dry bulb temperature and the three day average dry bulb temperature forecast.

2.1.1.2.2.5 Typically, one hour average temperature will be below 95°F in May, below 92°F between October and April, below 89°F between November and March, and below 85°F between December and February. However, weather forecasts should be consulted prior to isolating cooling tower fans and actual ambient temperatures should be monitored while fans are out of service. [4.2, 3.1.4.8]

2.1.1.2.2.6 Typically, the three day average temperature will be at least 7 degrees cooler than the daily high temperature. In the summer, the difference is typically even greater. The highest recorded average three day temperature is 89°F, whereas the highest recorded temperature is 102°F. [3.1.4.8]

2.1.1.2.2.7 Typically, 3 day average temperature will be below 82°F in May, below 78°F between October and April, below 76°F between November and March, and below 73°F between December and EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 26 OF 119 February. However, weather forecasts should be consulted prior to isolating cooling tower fans and actual ambient dry bulb temperature should be monitored while fans are out of service.

[4.2, 3.1.4.8]

2.1.1.2.3 A DCT tube bundle may be isolated for maintenance at any ambient temperature as long as at least 14 DCT fans meet all other conditions for operability except that three of the fans are associated with an isolated tube bundle. To clarify, at least 7 WCT fans must be operable and at least 14 DCT fans must be capable of starting and running in fast speed* [8.1]

[4.4.1]

In the event of a tornado watch, all tube bundles under the missile shield and their associated fans shall be operable or the DCT should be declared inoperable. See sections [2.1.3.2] and [5.7.3.6] for more information.

2.1.1.2.3.1 In order to protect the assumptions for CCW flow rate in the DCT tube bundle isolation analysis, the acceptance criteria for CCW flow balance should ensure total CCW flow at least satisfies individual component CCW flow requirements in MNQ9-2 and total flow is less than 6,900 gpm for each train. [4.4.1]

2.1.1.2.3.2 The analysis shows that under worst case meteorological conditions and one DCT tube bundle isolated, the water inventory margin will be 26,600 gallons and CCW supply temperature could be maintained at 116°F with ACC-126A(B) fully open. [8.1]

2.1.1.2.3.3 Margin will increase and fan restrictions will reduce when lower seasonal ambient temperatures are credited.

2.1.1.2.4 The DCT has the capacity to supply CCW at 110°F while discipating the total bounding plant heat load without the aid of the WCT when the DPELHQWGU\EXOEWHPSHUDWXUHLV3°F accounting for bounding recirculation with all 15 DCT fans operable. [8.1]

2.1.1.3 Mission Time for Water Consumption 2.1.1.3.1 Decay heat reduces such that the DCT alone, without the aid of the CCW HX, is capable of providing 117.4°F maximum outlet water temperature while dissipating the total plant heat except for the Essential Chiller 1.4 days into a LBLOCA with all fans operable. Therefore, shell flow through the CCW HX will be secured within 2 days when all DCT fans are operable. CCW HX mission time is extended with DCT fans out of service. [8.1]

2.1.1.3.2 Decay heat reduces such that the DCT alone, without the aid of the CCW HX, is capable of providing 110°F maximum outlet water temperature EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 27 OF 119 while dissipating the total plant heat including the Essential Chiller 3.53 days into a LBLOCA with all fans operable. Therefore, the Essential Chiller cooling can be transferred back to the DRY TOWER mode within 4 days when all DCT fans are operable. WCT mission time is extended with DCT fans out of service. [8.1]

2.1.1.4 Operator Action for Managing Water Consumption 2.1.1.4.1 Total plant heat reduces by an amount greater than the bounding FPC heat load within 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months allowing restoration of FPC in 4 to 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months without exceeding the analyzed peak heat load. [3.1.1.46] At that time and up to 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months from the time FPC was initially isolated, bulk temperature in the spent fuel pool would be less than 180°F. [3.1.1.45]

2.1.1.4.1.1 Calculation ECM98-067 [3.1.1.45] demonstrates that less than 825 gpm of CCW supplied at 120°F to the FPC HX will maintain spent fuel pool cooling bulk temperature below 180°F with bounding normal operation spent fuel heat load.

2.1.1.4.1.2 MNQ9-2 [3.1.1.53] shows that acceptable CCW flow to essential loads continues to achievable after lining up Fuel Pool Cooling with up to 850 gpm after an accident. [4.4.1]

2.1.1.4.1.3 ECC98-015 [3.1.1.18] evaluates spent fuel pool temperatures up to 212°F.

2.1.1.4.2 The CCW Temperature Control Valve, ACC-126A(B) has a 10 hour1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months motive gas accumulator [3.1.1.38]. Therefore, after 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months into the LOOP, manual local operator action may be required to adjust the throttling position of ACC-126A(B) to control CCW supply temperature between 117°F and 120°F. Attachment [8.1.8] provides more details.

2.1.1.4.3 The analysis credits turning off WCT fans, if necessary, when WCT heat load is reduced to approximately that of the Essential Chiller. This is indicated by low ACCW flow through the CCW HX and ACC-126A(B) nearly closed. Turning off fans reduces evaporation, but may raise basin temperature above the analysis limit if heat load is high. [3.1.4.4] The evaluation in [8.3] shows that basin temperature will be acceptable in natural draft (no fans) with only the Essential Chiller load on the WCT.

This would be days into the event and would only be required if WCT makeup capability is unavailable. [8.1]

2.1.1.5 Margins and Conservatisms 2.1.1.5.1 DCT performance was verified by startup testing summarized in MNQ9-52

[3.2.1.15]. The performance indicated by the Hudson Products thermal performance curves, which are used as the basis for this analysis, is conservative. This is based on the DCT heat transfer excess capacity of between 11.95% and 20.3% over that indicated by the Hudson Products EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 28 OF 119 curves as was demonstrated by preoperational testing. The excess capacity is not credited in the design basis, but may be considered as design conservatism. [4.6.2]

2.1.1.5.2 The CCW HX performance is periodically tested in accordance with GL89-13 [3.2.3.4] with PE-004-021 [3.1.6.17] to verify that the fouling factor is less than or equal to the allowable fouling factor. Performance trends show significant margin currently exists. The most recent test in 2014 shows actual fouling including uncertainty less than 0.0005 hr ft2 °F / BTU.

There are currently no plugged CCW HX tubes. [4.6.3]

2.1.1.5.3 WCT performance is periodically verified in accordance with PE-004-033

[3.1.6.19] The 2014 WCT testing performed on WO 52348919 [3.2.6.21]

and WO 52372443 [3.2.6.22] concluded that the current performance indicates no degradation and is 108.1% (train A) and 104.7% (train B) of that predicted by the Zurn performance curves after factoring in uncertainty. The excess capacity is not credited in the design basis, but may be considered as design conservatism. [4.6.4]

2.1.1.5.4 The analysis is based on a combination of the highest reactor core decay heat (End of Cycle) and spent fuel pool decay heat (Beginning of Cycle),

which do not occur simultaneously. The core decay heat is approximately 4.5 x 106 BTU/hr lower than the values used in this analysis at the beginning of the cycle, while the spent fuel pool decay heat is approximately 11 x 106 BTU/hr lower than the values used in this analysis at the end of an operating cycle. However, this was not credited in the analysis and so the analysis is conservative for the entire operating cycle by at least 4.5 x 106 BTU/hr. A 25 day refueling outage is assumed for maximum fuel pool heat load. This is a conservative assumption based on historical outage performance. [5.1.2]

2.1.1.5.5 The analysis of mass and energy release from the RCS and the corresponding containment heat load on the UHS are based on upper bound decay heat, which adds approximately 5.5% above best estimate for the entire event. [3.1.1.11, 3.1.1.46]

2.1.1.5.6 WCT basin level is normally maintained just under the overflow level, which adds approximately 10,000 gallons of water available per train above that assumed in the analysis.

2.1.1.6 The SBLOCA event is evaluated to account for the portion of the EFW consumption that is needed from WCT basin inventory (6,000 gallons) to reach SDC entry conditions in the most limiting SBLOCA case, along with a very conservative, bounding containment heat load for a LBLOCA. [4.8.1]

and [5.1.9] justify that the LBLOCA (DEDLSB) is the bounding event for peak heat load on the CCW system and overall water consumption.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 29 OF 119 2.1.2 Non-LOCA Accident:

2.1.2.1 The Non-LOCA accident analysis demonstrates that the design is such that the reactor can be taken from normal operating conditions to cold shutdown

(<200°F) in a reasonable period of time and maintained for at least 30 days using only safety-grade systems, assuming a LOOP and worst case single failure, which envelopes BTP 5-4 [3.2.3.2.1] requirements and RG 1.27

[3.2.3.3] requirements. The stored water inventory in the WCT basins and the CSP is sufficient for cooling the RCS to cold shutdown (<200°F) and for cooling the RCS, required auxiliaries, and the spent fuel pool (<180°F)for at least 30 days considering a LOOP and a worst case single failure. [8.2]

2.1.2.2 The analysis accounts for the portion of the EFW consumption that is needed from the WCT basin inventory. CN-SEE-II-09-21 [3.1.1.14], shows that with two ADVs, EFW consumption to reach SDC is conservatively 171,200 gallons. With only one ADV, EFW consumption to reach SDC is conservatively 229,600 gallons. However, if only one ADV is available, then two UHS trains would be available based on the single failure criterion. The capacity of two DCT trains exceeds the total plant heat load 14 days after shutdown for any anticipated ambient temperature. Therefore, the evaluation shows that the total water consumption is larger overall with only one UHS train and two ADVs. In addition, if SDC entry conditions are reached sooner, less EFW will be used. Therefore, the failure of an EDG is the limiting malfunction for the UHS analysis and a longer time to initiate SDC maximizes water consumption. Therefore, it is appropriate to use 171,200 gallons as the maximum EFW consumption. [5.2.5.1.1]

2.1.2.3 Normally, it would be desirable to maintain the spent fuel pool temperature below 140°F. However, the spent fuel pool may exceed 140°F during accident conditions. ECC98-015 [3.1.1.18] qualifies the spent fuel pool for accident temperature up to 212°F. Therefore, maintaining low CCW temperatures and continuous FPC operation should not be considered requirements during accident conditions.

2.1.2.4 Attachment 8.2 demonstrates that cold shutdown can be reached in approximately 38 hours4.398148e-4 days 0.0106 hours 6.283069e-5 weeks 1.4459e-5 months with one train of UHS with CCW supply temperature controlled at ~117°F. The chart below illustrates that LOCA heat loads bound shutdown heat loads on the UHS for SDC entry anytime greater than 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months

[8.2].

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 30 OF 119 2.1.2.5 The heat transfer capacities of the DCT, the CCW HX, and the WCT for dissipating the bounding Non-LOCA accident heat loads under design basis meteorological conditions (3 day average 89F dry bulb and 50% RH) while supplying CCW temperature of 117°F are illustrated in attachment [8.2].

2.1.2.6 The results indicate that for all cases analyzed the water stored in the CSP and WCTs is sufficient for bringing the reactor to cold shutdown (reactor coolant temperature not more than 200°F) and for maintaining cold shutdown for at least 30 days. Thus, this calculation satisfies the requirements of RG 1.27 and BTP 5-4 for Class 2 Plants. The table below provides a summary for the cases analyzed with all fans operable and bounding meteorological conditions for the three day critical time period.

Total Inventory Total EFW from CSP EFW ACCW & ACCW and 2 WCT Required, Required, Required, Basins, Margin, Case gallons gallons gallons gallons gallons Failed EDG w SFP 171,200 62,900 234,100 501,624 267,524 Cooling Failed EDG w No SFP 171,200 29,000 200,200 501,624 301,424 Cooling 2.1.2.7 The chart in Attachment 8.2 illustrates the analysis timeline for the bounding Non-LOCA accident.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 31 OF 119 2.1.2.7.1 The analysis uses a CCW supply setpoint temperature of 117.4°F. Lower CCW supply setpoint with the same bounding ambient conditions would consume additional water.

2.1.2.8 The allowable CCW HX fouling factor is 0.0012 hr ft2 °F / BTU. [5.7.5]

2.1.2.9 The allowable CCW HX tube plugging is 63 tubes or 5%. [5.7.5]

2.1.2.10 The allowable DCT Tube plugging is 80 tubes or 2.4%. [5.7.3.2]

2.1.2.10.1Study cases were evaluated and confirmed that the water inventory margin is adequate to compensate for out-of-service fans using the fan requirements identified above and an isolated tube bundle as described above. See attachment [8.2] for details.

2.1.2.10.1.1 With 2 DCT fans out-of-service, peak heat load, and bounding ambient conditions, the CCW supply temperature can be controlled less than or equal to 119.5°F with a cooldown rate of 6°F/hr after SDC.

2.1.2.11 The analysis assumes a reasonable cool down rate of 6°F /hr after SDC conditions are reached. The cooldown rate is relatively low to protect the CCW supply temperature analysis limit during peak heat load for the first hour on SDC. Water inventory margin is also a concern if DCT fans are out of service and WCT makeup is unavailable. If the spent fuel pool heat is low

(>60 days since the previous refueling outage shutdown), or if ambient temperatures are mild, or if WCT makeup is available, then higher cooldown rates may be achieved without exceeding 120°F CCW supply temperature or challenging WCT basin inventory margin.

2.1.2.12 Operator action is credited for raising CCW supply temperature to ~117°F using the M/A station in the control room prior to initiating SDC to maximize DCT capacity and reduce water consumption.

2.1.2.13 The CCW Temperature Control Valve, ACC-126A(B) has a 10 hour1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months motive gas accumulator [3.1.1.38]. Therefore, after 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months into the LOOP, manual local operator action may be required to adjust the throttling position of ACC-126A(B) to control CCW supply temperature between 116°F and 118°F.

2.1.2.14 Reduced Fan / Tube Bundle Requirements Based on Ambient Dry Bulb Temperature 2.1.2.14.1Study cases confirmed that the UHS capacity margin is adequate to compensate for out-of-service fans and an isolated DCT tube bundle with certain ambient temperature restrictions. See Attachment [8.2] for details.

2.1.2.14.1.1 CCW supply temperature margin is limiting for the LBLOCA event because of the higher peak heat load as illustrated in the chart above.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 32 OF 119 2.1.2.14.1.2 The UHS must be able to provide coolant at the required temperature and must also last for at least 30 days. Therefore, water inventory margin will be considered below and the most limiting fan requirements must be used.

2.1.2.14.2Study cases confirmed that the water inventory margin is adequate to compensate for out-of-service fans and an isolated tube bundle. The results show that the water inventory margin and fan restrictions are more limiting for the LOCA than for the Non-LOCA accident because credit is taken to adjust CCW supply temperature to match the setpoint for a LOCA and peak and total heat loads are lower for the non-LOCA accident.

Therefore, the margins for the LOCA should be used for determining allowable system leakage. Concurrent LOCA and seismic events are not postulated. Therefore, the margin for the Non-LOCA accident may be credited for leakage that could be caused by seismic events. See attachment series [8.2] for details.

2.1.3 Tornado

2.1.3.1 The analysis demonstrates that the available water inventory, with replenishment described in ECM07-002 [3.1.1.36] and the capability of the tornado missile protected parts of the UHS (60% DCT*, CCW HX, and WCT on natural draft), assuming credited operator action, are sufficient for dissipating the bounding design basis tornado heat loads while supplying limiting cooling water temperature and flow at the required times during the event. [8.3]

2.1.3.2 For 7 day aYHUDJHDPELHQWGU\EXOEWHPSHUDWXUH74°F, which is not exceeded between late October and early April, only 8 DCT fans are required (accounting for additional recirculation) to provide the same heat removal capacity as 9 DCT fans at the bounding 7 day average ambient dry bulb temperature.

In the event of a tornado watch where 7 day average temperature forecast is

>74°F, all DCT tube bundles under the missile shield and their associated fans shall be operable or the DCT should be declared inoperable. In the event of a tornado watch ZKHUHGD\DYHUDJHWHPSHUDWXUHIRUHFDVWLV4°F, all DCT tube bundles under the missile shield and 8 of their 9 associated fans shall be operable or the DCT should be declared inoperable. However, weather forecasts should be consulted prior to isolating cooling tower fans and actual ambient temperatures should be monitored while fans are out of service.

2.1.3.2.1 Heat dissipation is accomplished as follows:

2.1.3.2.1.1 RCS Cooldown Rate 2.1.3.2.1.1.1 The analysis assumes relatively slow RCS cooldown rates of EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 33 OF 119 40°F/hr from normal operating temperature to 350°F and 5°F/hr from 350°F to 200°F to slow the consumption of water for EFW and cooling tower evaporation. Under bounding ambient conditions, SDC HX heat load may need to be limited to 47 x 106 BTU/hr in order to maintain CCW supply temperature below the analysis limit of 120°F. Higher cooldown rates could be used or during cooler ambient conditions, or if less UHS damage occurred, or if replenishment can be achieved sooner than evaluated. After SDC entry conditions are reached, steam generator heat removal supplements SDC Hx heat removal.

This may be performed by monitoring CCW supply temperature and throttling SI-415A(B), SDC HX A(B) Temperature Control, and MS-116A(B), ADV, to control CCW temperature and RCS temperature. [8.3]

2.1.3.2.1.2 Emergency Feedwater (EFW) 2.1.3.2.1.2.1 EFW is available immediately to remove decay heat. [5.3]

2.1.3.2.1.2.2 EFW operates for 4.5 days following the tornado until the sum of decay heat, auxiliary heat, essential chiller heat, and FPC heat loads is less than the capacity of the undamaged parts of the DCT with an exit temperature of 120°F. EFW consumption is significantly reduced after initiating SDC. [8.3]

2.1.3.2.1.2.3 Makeup from the WCT basins to the CSP may be required within 6.75 hours8.680556e-4 days 0.0208 hours 1.240079e-4 weeks 2.85375e-5 months after tornado. [8.3]

2.1.3.2.1.2.4 Cross-connecting the WCT basins may be required within 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months after tornado. [8.3]

2.1.3.2.1.2.5 Replenishing the inventory in the WCT basins from the CW system or other available sources identified in ECM07-002

[3.1.1.36] at a rate of ~150 gpm may be required within 32 hours3.703704e-4 days 0.00889 hours 5.291005e-5 weeks 1.2176e-5 months . [8.3]

2.1.3.2.1.2.6 If the stagnant water from the CW system piping is used, then replenishment of the CW piping at a rate of ~25 gpm may be required within 7 days. [8.3]

2.1.3.2.1.3 WCT 2.1.3.2.1.3.1 The WCT is available for heat removal immediately in natural draft mode with no fans to remove plant auxiliary heat loads and chiller heat load. [5.3]

2.1.3.2.1.3.2 The WCT operates in natural draft mode for the duration of the event with 16 x 106 BTU/hr of heat duty from the auxiliaries and essential chiller for the first two hours and 4.2 x 106 BTU/hr of EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 34 OF 119 heat duty from the essential chillers plus a small portion (up to 10 x 106 BTU/hr) of the heat from the other plant loads for the remainder of the event until the total plant heat is less than the DCT capacity with an exit temperature of 110°F, which could be up to 57 days. [8.3]

2.1.3.2.1.3.3 The CCW Temperature Control Valve, ACC-126A(B) controls the heat transferred to the WCT and has a 10 hour1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months motive gas accumulator [3.1.1.38]. Therefore, after 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months into the LOOP, manual local operator action may be required to adjust the throttling position of ACC-126A(B) to control CCW supply temperature between 117°F and 120°F. Controlling the CCW temperature high reduces the heat transferred to the WCT and helps to maintain WCT basin water temperature less than 110°F for the Essential Chiller.

2.1.3.2.1.4 DCT 2.1.3.2.1.4.1 The DCT is bypassed immediately following the event in order to isolate missile damaged tube bundles. [5.3]

2.1.3.2.1.4.2 The missile protected 60% of the DCT is available for auxiliary and FPC heat loads after 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months following the tornado, with operator action to isolate damaged tube bundles and restore the undamaged tube bundles to service. [5.3]

2.1.3.2.1.4.3 The missile protected 60% of the DCT is available for auxiliary, FPC, and SDC heat loads following the tornado, when the sum of the decay heat, auxiliary heat, and FPC heat loads is less than the DCT capacity with an exit temperature of 120°F. [5.3]

2.1.3.2.1.4.3.1 In order to keep CCW supply temperature less than 120°F during bounding ambient temperatures, SDC HX heat load must be limited to approximately 47 x 106 BTU/hr. Steam generator heat removal may need to be maintained for up to 4.5 days after shutdown.

2.1.3.2.1.4.4 The allowable DCT Tube plugging is maintained at 80 tubes or 2.4%. [5.7.3.2]

2.1.3.2.1.5 CCW HX 2.1.3.2.1.5.1 The allowable CCW HX fouling factor is maintained at 0.0012 hr ft2 °F / BTU. [5.7.5]

2.1.3.2.1.5.2 The allowable CCW HX tube plugging is maintained at 63 tubes or 5%. [5.7.5]

2.1.3.3 The analysis assumes design basis meteorological conditions (7 day average 86F dry bulb and 50% RH) while supplying design basis CCW temperature EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 35 OF 119 (120°F) as detailed in attachment [8.3].

2.1.3.4 This calculation shows that the Tornado Water Replenishment Plan detailed in ECM07-002 [3.1.1.36] provides sufficient water supply to meet the requirements of the design basis tornado event. The table below provides a summary for the cases analyzed.

Total Inventory Total EFW from CSP

& ACCW and 2 EFW ACCW & Leakage WCT Replenishment Required, Required, Required, Basins, Required*,

Case gallons gallons gallons gallons gallons Tornado w Failed 869,220 708,096 1,871,000 441,215 1,429,785 EDG w SFP Cooling [8.3 ]

Tornado w Failed 741,125 361,710 1,536,000 441,215 1,094,785 EDG w/o SFP Cooling [8.3 ]

Heat dissipation for the design basis tornado event consumes all of the safety related inventory and requires makeup from non-seismic sources within specified time limits. The replenishment requirement includes potential leakage past the DCT tube bundle isolation valves (10 gpm total system leakage = 820,800 gal).

688,045 gallons is available from the stagnant CW piping.

2.1.3.5 The chart in Attachment [8.3] illustrates the total water consumption timeline for the design basis tornado event.

2.1.4 Core Offload:

2.1.4.1 One train of UHS operating with one CCW Pump, one ACCW pump, 15 DCT fans and 8 WCT fans can adequately dissipate the heat from an EDG, an Essential Chiller, a LPSI pump, and a bounding full spent fuel pool with a full core discharged 10 days subcritical while supplying CCW at a temperature of 90.4°F, which keeps the fuel pool bulk temperature below regulatory limit of 140°F, during the period of cooler ambient conditions between October 15 and April 15 when ambient one hour average dry bulb temperature is not expected to exceed 87°F.

2.1.4.1.1 Full core offload starting 10 days after shutdown has a maximum spent fuel pool heat load of 35,703,000 BTU/hr. Under bounding meteorological conditions (85°F dry bulb / 75°F wet bulb) associated with typical Refueling Outages with bounding season ambient temperature between October 20 and April 21, the UHS is capable of providing the required 91.8°F CCW supply temperature. [3.1.1.45] [8.7.1]

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 36 OF 119 2.1.4.1.2 DCT recirculation was assumed to be only 2°F based on the relatively low DCT water inlet temperature of 105°F compared to LOCA conditions, where the inlet temperature would be more than 160°F and bounding recirculation would be only 7.7°F. Wet bulb temperature is conservatively assumed to match ambient dry bulb temperature.

2.1.4.1.3 The methodology in this calculation and in ECM98-067 [3.1.1.45], may be performed with realistic inputs for CCW HX fouling, decay heat, and ambient temperatures, to support cycle specific evaluations to allow shorter in-vessel hold times.

2.1.4.1.3.1 Attachment [8.7.1] shows the UHS model worksheet that determines the CCW supply temperature based on UHS heat loads and ambient conditions.

2.1.4.1.3.2 ECM98-067 [3.1.1.45] provides the FPC HX worksheets.

2.1.4.1.3.3 When evaluating cycle specific DCT fan requirements on the protected train during full core offoad, consider the potential for a design basis tornado.

2.1.4.1.3.4 If realistic HX fouling factors are used, the FPC HXs can maintain 140 °F spent fuel pool temperature with a bounding heat of 40 MBTU/hr from a core offload starting 6 days after shutdown with 86°F CCW supply temperature. The UHS can supply 86°F CCW when ambient dry bulb temperature is 81°F and wet bulb temperature is 74°F, which are not exceeded between November and February. This is an example of a potential cycle specific evaluation and other combinations can be used when appropriately justified in a cycle specific EC.

2.1.4.2 Two trains of UHS operating with two CCW pumps, two ACCW pumps, 30 DCT fans and 16 WCT fans can adequately dissipate the heat from two EDGs, two Essential Chillers, two LPSI pumps, and a bounding abnormal full spent fuel pool with full core discharged 150 hours0.00174 days 0.0417 hours 2.480159e-4 weeks 5.7075e-5 months after shutdown where the previous batch had been stored only 36 days since the previous shutdown during bounding meteorological conditions for the three day critical time period while maintain spent fuel pool temperature less than 150°F, which is much less than the regulatory criteria of below boiling in NUREG 0800, 9.1.3.

[3.1.1.45]. ECC98-015 [3.1.1.18] qualifies the spent fuel pool for accident temperature up to 212°F.

2.1.4.3 Administrative controls credited to support this analysis are:

2.1.4.3.1 Commencing a full core offload after the reactor has been subcritical for at least 10 days (240 hours0.00278 days 0.0667 hours 3.968254e-4 weeks 9.132e-5 months ) typically provides adequate margin to account for the possibility of record high temperatures that might occur coincident with a worst case single failure. Commencing a full core offload at less EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 37 OF 119 than 10 days subcritical would require a cycle specific evaluation.

2.1.4.3.2 Full core offload must not commence after April 15 or before October 15 without a cycle specific evaluation of anticipated ambient conditions and schedule restrictions.

2.1.4.3.3 Both FPC pumps will be available prior to commencement of fuel movement during refueling.

2.1.4.3.4 The normal FPC HX will be aligned for service and the BUFPC HX will be available for service.

2.1.4.3.5 All DCT and WCT fans must be available during core offload or an engineering evaluation of the anticipated ambient conditions must be performed to ensure required CCW supply temperature can be delivered with fewer fans.

2.1.4.3.6 Containment Fan Coolers are isolated from CCW.

2.1.4.3.7 If only one train of UHS, one CCW pump, and one FPC pump is available during full core offload with the reactor subcritical less than 15 days, then the non-functional train must be isolated such that all of the CCW flow will be through the cooling towers with the functional fans and the CCW HX with the functional ACCW pump. This is accomplished by splitting the CCW trains, using guidance in OP-901-510 [3.1.6.9], as applicable. In addition, CC-963A(B) must be placed in the setpoint position to ensure adequate CCW flow through the FPC HX. The FPC CCW Temperature Control Valve, CC-620, will be required to be manually reset and opened after the trains are split.

2.1.4.3.8 The capacity of the BUFPC HX alone is not sufficient to handle the spent fuel pool heat load during a full core offload. With only the FPC BU HX in service a heat load calculation must be performed prior to commencing a partial core offload. The calculated spent fuel pool heat load, for removing the main FPC HX from service should not exceed 13.5 x 106 Btu/hr.

2.1.4.3.9 Evaluations of one time deviations to administrative controls described in above may be performed as follows:

2.1.4.3.9.1 Process an Engineering Evaluation Engineering Change.

2.1.4.3.9.2 A markup or revision to this calculation is not required.

2.1.4.3.9.3 Use methodology consistent with the methods in this calculation and ECM98-067.

2.1.4.3.9.4 Adjust inputs and assumptions from bounding values to realistic cycle specific values with appropriate justification.

2.1.4.3.9.5 Cycle specific inputs that are likely to reduce conservatisms and allow shorter in-reactor hold times are as follows:

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 38 OF 119 2.1.4.3.9.5.1 Previously stored fuel heat load.

2.1.4.3.9.5.2 Average assembly operating time.

2.1.4.3.9.5.3 Ambient environmental temperature conditions.

2.1.4.3.9.5.4 HX fouling factor and tube plugging.

2.1.4.3.9.6 Consider the potential for a design basis tornado when evaluating Dry Cooling Tower fan requirements on the protected train during full core offload.

2.1.5 Normal Shutdown -

2.1.5.1 The UHS is capable of dissipating heat removed from the reactor and its auxiliaries during a normal shutdown while the CCW system supplies sufficient cooling water to remove heat from the safety related and non-safety related auxiliaries.

2.1.5.1.1 The bounding normal shutdown plant heat load on the UHS is 126,700,000 BTU/hr or 63,350,000 BTU/hr per train. [4.3, 5.6]

2.1.5.1.2 The heat transfer capacities of the DCT, CCW HX, and WCT while providing 100.8°F CCW supply temperature with ambient dry bulb temperature at 98°F and wet bulb temperature of 85°F are 35,030,000 BTU/hr, 28,330,000 BTU/hr, and 28,330,000 BTU/hr, respectively. [8.5]

2.1.6 Fuel Shuffle Refueling -

2.1.6.1 The UHS is capable of dissipating heat removed from the reactor and its auxiliaries during refueling while the CCW system supplies sufficient cooling water to remove heat from the safety related and non-safety related auxiliaries.

2.1.6.1.1 The bounding refueling heat load is the full core offload, which is discussed in section [2.1.4].

2.1.6.1.2 The fuel shuffle offload (108 assemblies) has a bounding plant heat load of 58,473,000 BTU/hr or 29,236,500 BTU/hr per train based on commencing the core shuffle 3 days after shutdown. [3.1.1.45]

2.1.6.1.3 The heat transfer capacities of the DCT, CCW HX, and WCT while providing 89.5°F CCW supply temperature with ambient dry bulb temperature at 85°F are 20,200,000 BTU/hr, 9,010,000 BTU/hr, and 9,010,000 BTU/hr, respectively. [8.6]

2.1.7 Normal Operation -

2.1.7.1 The UHS is capable of dissipating heat removed from the reactor and its auxiliaries during normal operation while the CCW system supplies sufficient cooling water to remove heat from the safety related and non-safety related auxiliaries.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 39 OF 119 2.1.7.1.1 The bounding normal operation plant heat load on the UHS is 91,120,000 BTU/hr or 45,560,000 BTU/hr per train with concentrators running. [4.3]

2.1.7.1.2 The heat transfer capacities of each DCT, CCW HX and WCT while providing 100.3°F CCW supply temperature at the bounding 102°F dry bulb and 78°F wet bulb are 21,200,000 BTU/hr, 24,300,000 BTU/hr, and 24,300,000 BTU/hr, respectively. [8.7]

2.1.7.1.2.1 If the concentrators are secured, then CCW supply temperature can be maintained at 98.84°F. The heat transfer capacities of the DCT, CCW HX, and WCT are 12,300,000 BTU/hr, 21,600,000 BTU/hr, and 21,600,000 BTU/hr, respectively. [8.7]

2.1.8 120°F CCW supply temperature is adequate to maintain Emergency Diesel Generator (EDG) temperatures within manufacturer specified alarm limits given design basis bounding heat load and limiting HX flow rates during a LOCA or tornado. [8.7.1]

2.1.8.1 Calculations listed below show that 120°F CCW supply temperature is adequate to maintain design basis functions of other safety related equipment, given design basis bounding heat load and limiting HX flow rates during a LOCA or tornado, namely:

2.1.8.1.1 Containment Fan Coolers (CFC) - ECS98-015 [3.1.1.51]

2.1.8.1.2 Shutdown Cooling (SDC) HX - ECS98-015 [3.1.1.51]

2.1.8.1.3 Containment Spray (CS) pump - ECM97-028 [3.1.1.44]

2.1.8.1.4 High Pressure Safety Injection (HPSI) Pump - ECM97-001 [3.1.1.41]

2.1.8.1.5 Low Pressure Safety Injection (LPSI) pump - ECM97-001 [3.1.1.41]

2.1.8.1.6 Fuel Pool Cooling (FPC) - ECM98-067 [3.1.1.45]

2.2 The acceptance criteria for demonstrating the throttling capability of ACC-126A(B) is to ensure that there is no auto start of the main ACCW pump when using the ACCW jockey pump for maintaining ACCW piping full of water. [8.9]

2.3 The bounding 7 day average brake horsepower for the ACCW Pumps during a LOCA is 242 hp. [8.10]

2.4 Templates, in the form of Mathcad worksheets, for evaluating the period thermal performance tests of the WCT and CCW HX are provided in Attachment [8.11].

2.5 Licensing Basis Document Output 2.5.1 The chart in Attachments [8.12.1] show distribution of LOCA heat load dissipation between the DCT and WCT and may be used as the basis for FSAR Figures 9.2-4, Heat Load Dissipation of UHS after LOCA.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 40 OF 119 2.5.2 The chart in Attachments [8.12.2] show distribution of LOCA heat load dissipation between the DCT and WCT and may be used as the basis for 9.2-4a, Wet Cooling Tower Integrated Heat Load Curve After LOCA.

2.5.3 The chart in Attachment [8.12.3] shows DCT heat removal capacity vs. dry bulb temperature and may be used as a basis for FSAR Figures 9.2-5, Heat Removal Capacity of Dry Cooling Tower vs. Dry Bulb Temperature.

2.5.4 The chart in Attachment [8.12.4] shows bounding meteorological parameters for design basis heat dissipation capacity and may be used as a basis for FSAR Figure 9.2-5a, Ultimate Heat Sink Design Basis Meteorological Conditions.

2.5.5 The table in Attachment [8.12.5], Fan Requirements, provides a basis for TS table 3.7-3, Ultimate Heat Sink Minimum Fan Requirements per Train.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 41 OF 119 3.0 References 3.1 Relationships 3.1.1 Calculations 3.1.1.1 1-B, Containment Fan Cooler Sizing 3.1.1.2 2-D, CEDM Cooling 3.1.1.3 5-A, Safeguard Pump Rooms A & B 3.1.1.4 5-B, Shutdown Cooling Heat Exchanger Rooms A & B 3.1.1.5 5-C, Component Cooling Water Pump and Heat Exchanger Room Heat Loads 3.1.1.6 5-T, Essential Chilled Water Cooling Loads and Coil Performance Determination 3.1.1.7 9C2-5Y, Chiller Heat Rejection 3.1.1.8 A15503-C-001, Development of FPC, SDC, and EDG Heat Exchanger Models 3.1.1.9 CN-OA-06-5, Post-LOCA Long-Term Cooling ECCS Performance Analysis for Waterford 3 with 20% Steam Generator Tubes Plugged 3.1.1.10 CN-OA-08-50, Waterford Unit 3 Evaluation of the Impact of RSG Implementation on Long Term Cooling Analysis 3.1.1.11 CN-SCC-16-007, Waterford-3 Long Term Containment Mass and Energy Releases for Ultimate Heat Sink Evaluation 3.1.1.12 CN-SEE-04-28, Waterford 3 3716 MWth Power Uprate EnergiTools Heat Balances 3.1.1.13 CN-SEE-II-08-6, Shutdown Cooling Analysis for the Waterford 3 RSG Program 3.1.1.14 CN-SEE-II-09-21, Natural Circulation Cooldown to 350°F to Support BTP 5-4 Criteria for Waterford 3 with Replacement Steam Generators 3.1.1.15 CN-SEE-III-08-49, Waterford 3 Additional EnergiTools Cases for the RSG Project 3.1.1.16 CN-TAS-03-30, Waterford 3 3716 MWth Power Uprate Project - Chapter 15 EAB and LPZ Dose Consequences 3.1.1.17 CN-WFE-03-9, Waterford 3 3716 MWT Power Uprate Decay Heat Calculations Using ANSI / ANS 5.1 - 1994 3.1.1.18 ECC98-015, FHB Structural Analysis of Spent Fuel Pool Racks, DC-3465 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 42 OF 119 3.1.1.19 ECE90-006, Emergency Diesel Generator Loading and Fuel Oil Consumption 3.1.1.20 ECI01-003, IST Instrument Uncertainties 3.1.1.21 ECI01-010, Determination of Cooling Water Systems Measurement Channels Functional Safety Significance 3.1.1.22 ECI01-002, COLSS Secondary Calometric Measurement Uncertainty 3.1.1.23 ECI91-003, EFW CSP Level Uncertainty 3.1.1.24 ECI91-005, Basin Level Instrument Uncertainty 3.1.1.25 ECI91-014, Component Cooling Water Heat Exchanger Outlet Temperature (ACCW Control) Instrument Uncertainty 3.1.1.26 ECI91-029, Primary Meteorological Tower Vertical Temperature Difference Instrumentation Loop Uncertainty Calculation 3.1.1.27 ECI91-036, Component Cooling Water Heat Exchanger Outlet Temperature (Dry Fan Control) Instrument Loop Uncertainty Calculation 3.1.1.28 ECI91-037, ACC-Wet Cooling Tower Basin Temperature Instrumentation Loop Uncertainty 3.1.1.29 ECI91-046, ACCW Flow Indicator Loop Uncertainty 3.1.1.30 ECI92-002, CCW from EDG Instrument Uncertainty 3.1.1.31 ECI95-004, CCW from CFC Instrument Uncertainty 3.1.1.32 ECI97-001, SDC HX CCW Flow Instrument Uncertainty 3.1.1.33 ECI08-001, ACCW from CCW HX Flow Instrument Uncertainty 3.1.1.34 ECM03-002, CSP Water Inventory Needed for Cooling the Waterford 3 RCS with RSGs and a Full Core of NGF via the EFW System 3.1.1.35 ECM06-002, Insulation Removal Limits - Piping Inspections in Safeguards Pump Room, SDC HX Room, and Wing Area 3.1.1.36 ECM07-002, Design Basis Requirements for Wet Cooling Tower Basin Replenishment System 3.1.1.37 ECM15-002, Impact of Concentrated Tube Plugging Dry Cooling Tower 3.1.1.38 ECM89-002, Nitrogen Accumulator Leak Rate Calculation 3.1.1.39 ECM89-004, Water Levels Inside Containment Post-LOCA 3.1.1.40 ECM96-013, Auxiliary Component Cooling Water Jockey Pump Analysis 3.1.1.41 ECM97-001, CCW Flow to HPSI / LPSI Pumps 3.1.1.42 ECM97-006, CCW Makeup EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 43 OF 119 3.1.1.43 ECM97-022, Makeup Capability to Wet Cooling Tower Basins 3.1.1.44 ECM97-028, Cooling Water Flow Requirements for Containment Spray Pumps 3.1.1.45 ECM98-067, Limiting Single Failure Thermal-Hydraulic Analysis of Waterford 3 Spent Fuel Pool 3.1.1.46 ECS05-013, Ultimate Heat Sink Containment Heat Loads 3.1.1.47 ECM09-005, Air Operated Valves - Design Basis Accident Times 3.1.1.48 ECS96-003, Spent Fuel Pool Heat Loads for a Full Spent Fuel Pool and SFP Cask Storage Area 3.1.1.49 ECS96-015, Containment Cooler Performance Analysis 3.1.1.50 ECS98-013, EOP Feedwater Curves 3.1.1.51 ECS98-015, Containment P&T Response Analysis - Steam Generator Replacement Project 3.1.1.52 MNQ9-1, Shutdown Heat Exchanger U Value 3.1.1.53 MNQ9-2, Component Cooling Water Flow Analysis 3.1.1.54 MNQ9-33, Component Cooling Water System Volume 3.1.1.55 MNQ9-38, Capacity of Wet Cooling Tower Basins 3.1.1.56 MNQ9-50, ACCW System Resistance 3.1.1.57 MNQ9-65, Component Cooling Water Temperatures 3.1.2 Design Basis Documents 3.1.2.1 W3-DBD-1, Safety Injection System 3.1.2.2 W3-DBD-2, Emergency Diesel Generator and Automatic Load Sequencer 3.1.2.3 W3-DBD-3, Emergency Feedwater System 3.1.2.4 W3-DBD-4, Component Cooling Water / Auxiliary Component Cooling Water 3.1.2.5 W3-DBD-9, Reactor Coolant System & Steam Generator Blowdown System 3.1.2.6 W3-DBD-13, Containment Spray System 3.1.2.7 W3-DBD-23, Fuel Handling System 3.1.2.8 W3-DBD-37, Essential Chilled Water System EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 44 OF 119 3.1.3 Drawings 3.1.3.1 1564-157, Atlas Spent Fuel Pool Heat Exchanger 3.1.3.2 1564-1998, Emergency Diesel Generator B Cooling Water Schematic 3.1.3.3 1564-2000, Emergency Diesel Generator Intake and Exhaust 3.1.3.4 1564-2001, Emergency Diesel Generator Lube Oil Schematic 3.1.3.5 1564-2002, Emergency Diesel Generator Jacket Water Schematic 3.1.3.6 1564-4983, Dry Cooling Tower Data Sheet 3.1.3.7 1564-6182, Orifice Plate Calculations 3.1.3.8 4305-6258, Isometric Drawing CC ISO 746 3.1.3.9 4305-5706, Isometric Drawing CC ISO 790 3.1.3.10 5817-660, PAC CP-49 Wiring Diagram Sh 12 3.1.3.11 5817-661, PAC CP-49 Wiring Diagram Sh 11 3.1.3.12 5817-690, PAC CP-48 Wiring Diagram Sh 11 3.1.3.13 5817-698, PAC CP-48 Wiring Diagram Sh 3 3.1.3.14 5817-8938, YUBA Backup Fuel Pool Heat Exchanger 3.1.3.15 5817-9258, ACCW Pump A Performance Curve 3.1.3.16 5817-9259, ACCW Pump B Performance Curve 3.1.3.17 5817-9376, Emergency Diesel Generator A Cooling Water Schematic 3.1.3.18 5817-9517, Emergency Diesel Generator Intake and Exhaust 3.1.3.19 5817-9518, Emergency Diesel Generator Jacket Water Schematic 3.1.3.20 5817-5919, Emergency Diesel Generator Lube Oil Schematic 3.1.3.21 5817-10743, Name Plate (CCW Heat Exchanger) 3.1.3.22 5817-10744, Hub Channel Flange @ Tube Sheet 3.1.3.23 5817-10745, Hub Channel Flange @ Cover 3.1.3.24 5817-10746, Setting Plan for Component Cooling Water Heat Exchanger 3.1.3.25 5817-10747, Component Cooling Water Heat Exchanger Tube Sheet 3.1.3.26 5817-10748, Shell Support Details for Component Cooling Water Heat Exchanger 3.1.3.27 5817-10749, Channel Details for Component Cooling Heat Exchanger 3.1.3.28 5817-10750, Bundle and Hinge Details for Component Cooling Water Heat Exchanger EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 45 OF 119 3.1.3.29 5817-10751, Setting Plan for Component Cooling Water Heat Exchanger 3.1.3.30 5817-14291, Dry Cooling Tower Tube Map Train B 3.1.3.31 5817-14296, Dry Cooling Tower Tube Map Train A 3.1.3.32 5817-14476, Dry Cooling Tower Recirculation Barrier - Train A 3.1.3.33 5817-14480, Dry Cooling Tower Recirculation Barrier - Train B 3.1.3.34 5817-14487, Wet Cooling Tower Fan Covers 3.1.3.35 5817-14488, Dry Cooling Tower Fan Backflow Preventer 3.1.3.36 B425 Sheet T2000, Control Loop Diagram Fuel Pool Temperature 3.1.3.37 B425 Sheet T7075A1, Control Loop Diagram CC-Dry Cooling Tower A Fan Control 3.1.3.38 B425 Sheet T7075A2, Control Loop Diagram CCW Train A Temperature Control 3.1.3.39 B425 Sheet T7075B1, Control Loop Diagram CC-Dry Cooling Tower B Fan Control 3.1.3.40 B425 Sheet T7075B2, Control Loop Diagram CCW Train B Temperature Control 3.1.3.41 B425 Sheet T7077A, Control Loop Diagram ACC-Wet Cooling Tower A Basin Temperature 3.1.3.42 B425 Sheet T7077B, Control Loop Diagram ACC-Wet Cooling Tower B Basin Temperature 3.1.3.43 ESSE-CC-231, Component Cooling Water 3.1.3.44 ESSE-CC-232, Component Cooling Water 3.1.3.45 G160 Sheet 1, Flow Diagram Component Cooling Water 3.1.3.46 G160 Sheet 2, Flow Diagram Component Cooling Water 3.1.3.47 G160 Sheet 3, Flow Diagram Component Cooling Water 3.1.3.48 G160 Sheet 4, Flow Diagram Component Cooling Water 3.1.3.49 G160 Sheet 5, Flow Diagram Component Cooling Water 3.1.3.50 G160 Sheet 6, Flow Diagram Component Cooling Water 3.1.4 Engineering Reports 3.1.4.1 WF3-ME-15-00004, (AREVA 51-9248198-001), Tube Sleeve Qualification for Dry Cooling Towers 3.1.4.2 WF3-ME-15-00011, (A13326-R-001), Waterford 3 Ultimate Heat Sink Project, Weather Investigation EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 46 OF 119 3.1.4.3 WF3-ME-15-00012, (A13326-R-002), Waterford 3 Ultimate Heat Sink CFD Investigation of the Wet and Dry Cooling Towers 3.1.4.4 WF3-ME-15-00013, (A13326-R-003), Waterford 3 Ultimate Heat Sink Project, UHS Model 3.1.4.5 WF3-ME-15-00014, (A14386-R-001), Waterford 3 Ultimate Heat Sink Project CFD Investigation of the Deflector Wall Modification 3.1.4.6 WF3-ME-15-00015, (JCA-WFD-081575), Assessment of the Impact of Air Inlet Height Reduction on Waterford Unit 3 Wet Cooling Tower Thermal Performance Efficiency 3.1.4.7 WF3-ME-15-00016, (JCA-WFD-031289), Thermal Performance Analysis of the Waterford Steam Electric Station Unit 3 Wet Cooling Tower Design with Multiple Fans Taken Out of Service 3.1.4.8 WF3-ME-16-00001, Meteorological Parameters and Parameter Relationships for Design and Operability of the Waterford 3 Ultimate Heat Sink 3.1.4.9 WF3-ME-16-00011, (JCA-LPI-0115987), Waterford 3 WCT Engineering Analysis Submittals 3.1.5 License Basis Documents 3.1.5.1 Technical Specifications 3.7.1.3, Condensate Storage Pool 3.1.5.2 Technical Specifications 3/4.7.3, Component Cooling Water and Auxiliary Component Cooling Water Systems 3.1.5.3 Technical Specifications 3/4.7.4, Ultimate Heat Sink 3.1.5.4 Technical Specifications Table 3.7-3, Ultimate Heat Sink Minimum Fan Requirements per Train 3.1.5.5 Technical Specifications 3.8.1.2, AC Sources Shutdown 3.1.5.6 FSAR Chapter 2, Site Characteristics 3.1.5.7 FSAR Chapter 3, Design of Structures, Components, Equipment, and Systems 3.1.5.8 FSAR Chapter 9, Auxiliary Systems 3.1.6 Procedures 3.1.6.1 EP-002-100, Technical Support Center (TSC) Activation, Operation, and Deactivation 3.1.6.2 OP-002-001, Auxiliary Component Cooling Water 3.1.6.3 OP-002-003, Component Cooling Water 3.1.6.4 OP-002-004, Chilled Water System EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 47 OF 119 3.1.6.5 OP-002-006, Fuel Pool Cooling and Purification 3.1.6.6 OP-009-002, Emergency Diesel Generator 3.1.6.7 OP-009-005, Shutdown Cooling 3.1.6.8 OP-100-014, Technical Specification Compliance 3.1.6.9 OP-901-510, Component Cooling Water System Malfunction 3.1.6.10 OP-901-513, Spent Fuel Pool Cooling Malfunction 3.1.6.11 OP-901-521, Severe Weather and Flooding 3.1.6.12 OP-902-002, Loss of Coolant Accident Recovery Procedure 3.1.6.13 OP-902-003, Loss of Offsite Power / Loss of Forced Circulation Recovery Procedure 3.1.6.14 OP-902-006, Loss of Main Feedwater Recovery Procedure 3.1.6.15 OP-902-008, Functional Recovery 3.1.6.16 OP-902-009, Standard Appendices 3.1.6.17 PE-004-021, CCW Heat Exchanger Performance Test 3.1.6.18 PE-004-024, CCW / ACCW Flow Balance 3.1.6.19 PE-004-033, Wet Cooling Tower A(B) Thermal Performance Test 3.1.6.20 RF-005-001, Fuel Movement 3.1.6.21 DEIC-I-502, Setpoint and Uncertainty Determination 3.1.7 Preventive Maintenance 3.1.7.1 PMID 14508 - 03, Pressure Wash DCT A Coils As Required 3.1.7.2 PMID 14508 - 05, DCT A Coil Cleanliness Inspection 3.1.7.3 PMID 14509 - 03, Pressure Wash DCT B Coils As Required 3.1.7.4 PMID 14509 - 05, DCT B Coil Cleanliness Inspection 3.1.7.5 PMID 34624 - 34627, DCT Tube Bundle Isolation Test 3.1.7.6 PMID 5382 - 01, Verify Train A Wet Tower and Dry Tower Fan 3.1.7.7 PMID 5382 - 03, Perform Cooling Tower A Predictive Maintenance 3.1.7.8 PMID 5540 - 01, DCT Tube Bundle Isolation Test 3.1.7.9 PMID 5541 - 02, DCT Tube Bundle Isolation Test 3.1.7.10 PMID 5543 - 5546, DCT Tube Bundle Isolation Test 3.1.7.11 PMID 7108, DCT Tube Bundle Isolation Test 3.1.7.12 PMID 7405, DCT Tube Bundle Isolation Test EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 48 OF 119 3.1.7.13 PMID 8549 - 01, Verify Train B Wet Tower and Dry Tower Fan 3.1.7.14 PMID 8549 - 02, Perform Cooling Tower B Predictive Maintenance 3.1.8 Specifications 3.1.8.1 1564.75, Component Cooling Water Heat Exchanger 3.1.8.2 1564.86, Component cooling water System Dry Cooling Towers 3.1.8.3 1564.114A, Mechanical Draft Cooling Towers and Accessories 3.1.8.4 1564.260, Emergency Diesel Generator and Sequenser 3.1.8.5 9270-PE-305, Spent Fuel Pool Heat Exchanger 3.1.9 Vendor Technical Documents 3.1.9.1 TD-A545.0015, Atlas Spent Fuel Pool Heat Exchanger 3.1.9.2 TD-B015.0025, Babcock and Wilcox Instruction Manual for the Containment Spray Pump Model 6X8X13SMK 3.1.9.3 TD-C629.0015, Cooper Bessemer KSV Diesel Generator Correspondence 3.1.9.4 TD-C629.0035, Emergency Diesel Generator Operation and Maintenance 3.1.9.5 TD-H291.0015, Hudson Cooling Equipment, Instruction Manual for Job ND002 and Duties of the Field Engineer Bulletin No. B12 3.1.9.6 TD-H291.0025, Hudson TUF-LITE Fan Data Installation and Operation Manual 3.1.9.7 TD-H291.0035, Hudson Cooling Equipment Gear Motor Installation and Operation Manual by Philadelphia Gear Corporation 3.1.9.8 TD-Z010.0025, Zurn Cooling Tower Technical Document 3.1.9.9 457000087, Component Cooling Water Heat Exchanger 3.1.9.10 457001250V1, Beckman Sampling System 3.1.9.11 457002178, YUBA Backup Spent Fuel Pool Heat Exchanger 3.1.10 Training Documents 3.1.10.1 SD-CC, Component Cooling Water System Desciption 3.2 Cross-References 3.2.1 Study or Obsolete Calculations 3.2.1.1 A13326-C-001, Evaluation of Operability with Isolated DCT Fan 3.2.1.2 A14067-C-001, Evaluation of Operabiltiy with Isolated DCT Coil 3.2.1.3 CDCC28717 (C-CE-135), Balance of Plant Design Criteria EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 49 OF 119 3.2.1.4 CDCC60207 (C-CE-9709), FSAR Update 3.2.1.5 ECM03-007, Study Calculation for the Review of UHS Atmospheric Temperature Design Parameters to Support EPU 3.2.1.6 ECM92-049, Study - CCW Heat Exchangers Performance 3.2.1.7 ECM94-005, Study - CCW Heat Exchanger A Performance 3.2.1.8 ECM95-009, Ultimate Heat Sink Fan Requirements under Various Ambient Conditions 3.2.1.9 ECM98-010, ACCW Supply to EFW System, RSB 5-1 Analysis 3.2.1.10 ECS91-009, PEIR 10923: Heat Transfer with Reduced CCW Flow 3.2.1.11 MNQ9-3, Heat Removal Capacities of DCT and WCT After LOCA 3.2.1.12 MNQ9-9, Wet Cooling Tower Losses During LOCA 3.2.1.13 MNQ9-10, Dry Cooling Tower and Wet Cooling Tower Capacities in Different Cases 3.2.1.14 MNQ9-17, Multiple Tornado Missile Protection of Cooling Towers 3.2.1.15 MNQ9-52, Ultimate Heat Sink Performance (study) 3.2.1.16 MNQ9-53, Ultimate Heat Sink Test - Tornado Case (study) 3.2.2 Standards, Text Books, and Articles 3.2.2.1 ANSI / ANS 5.1, Decay Heat Power in Light Water Reactors 3.2.2.2 ASHRAE Systems and Equipment Handbook, 1992, Pages 37.1 and 37.2 3.2.2.3 ASHRAE Fundamentals Handbook, 1989, Pages 6.14 and 6.15 3.2.2.4 ASHRAE Fundamentals Handbook, 2001 3.2.2.5 ATC-105, Acceptance Test Code for Water Cooling Towers, Cooling Tower Institute, Feb. 2000 3.2.2.6 EPRI TR-107397, Service Water Heat Exchanger Testing Guidelines 3.2.2.7 Kreith, Principles of Heat Transfer, International Textbook, 1965.

3.2.2.8 Taborek, J. Shell and Tube Heat Exchangers: Single Phase Flow, Heat Exchanger Design Handbook, Chapter 3.3, Hemisphere, NY, 1983.

3.2.2.9 Wolverine Tube Company, Engineering Data Book III, J. Thome, 2004 3.2.2.10 Bejan, Adrian; Kraus, Allan D., Heat Transfer Handbook, John Wiley &

Sons, 2003 3.2.2.11 Dunn, W. E. and Sullivan, S. M., Method for Analysis of Ultimate Heat Sink Cooling Tower Performance, University of Illinois at Urbana-Champaign, April 1986 (ADAMS Accession No. ML12146A145 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 50 OF 119 3.2.2.12 Janna, William S. Design of Fluid Thermal Systems, PWS-Kent, 1993 3.2.2.13 EN-ME-S-001-W, Tube Sleeve Installations for Dry Cooling Towers 3.2.2.14 EPRI 3002005337, Classical Heat Exchanger Analysis 3.2.2.15 EPRI 3002005340, Service Water Heat Exchanger Testing Guidelines 3.2.3 Regulatory Documents 3.2.3.1 10CFR50 Appendix A, General Design Criteria 3.2.3.2 NUREG-0800, Standard Review Plan 3.2.3.2.1 Branch Technical Position 5-4, Design Requirements of the Residual Heat Removal System 3.2.3.2.2 Branch Technical Position ASB 9-2, Residual Decay Energy for Light-Water Reactors for Long-Term Cooling 3.2.3.2.3 Section 9.1.3 , Spent Fuel Pool Cooling and Cleanup System 3.2.3.3 Regulatory Guide 1.27, Ultimate Heat Sink for Nuclear Power Plants 3.2.3.4 Generic Letter 89-13, Service Water System Problems Affecting Safety Related Equipment 3.2.3.5 NUREG 0693, Analysis of Ultimate Heat Sink Cooling Ponds 3.2.3.6 NUREG 0733, Analysis of Ultimate Heat Sink Spray Ponds 3.2.4 Engineering Changes, Evaluations, Letters 3.2.4.1 EC-52043, UHS Margin Restoration 3.2.4.2 EC-59101, DCT Tube Sleeving 3.2.4.3 EC-64750, Alternate DCT Tube Sleeve Configuration 3.2.4.4 CCE-2559, letter from A.L. Gaines [CE] to R.K. Stampley [Ebasco],

Subject:

CCW Requirement for Equipment in CEs Scope, dated 10/9/75 3.2.4.5 CCE-3328, letter from W.D. Mawhinney [CE] to R.K. Stampley [Ebasco],

Subject:

RCP CCW Requirements, dated 7/16/76 (CDCC82603) 3.2.4.6 CCE-9709, letter from R.P. ONeill [CE] to R. Burski[LP&L],

Subject:

FSAR Update, dated 9/18/87 3.2.4.7 C-CE-135, Combustion Engineering Balance of Plant Design Criteria (CDCC28717) 3.2.4.8 ER-W3-2005-0019-000, Raise EFW Level Control Setpoints to Support Actions for Submergence of Steam Generator U-Tubes 3.2.4.9 ES-LOU-1-76, Meteorological Conditions Following Tornado Passage, April 29, 1976 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 51 OF 119 3.2.4.10 ES-LOU-87-77, Design Meteorological Data for Ultimate Heat Sink, July 18, 1977 3.2.4.11 ES-LOU-91-77, FSAR Table 2.3-2(a) - Ultimate Heat Sink Design Parameters, August 2, 1977 3.2.4.12 PEIR OM-112, Post Accident Sampling System Operation 3.2.4.13 W3I82-0146, Confirmatory Issue 2.4.5, Ultimate Heat Sink Testing, February 11, 1983 3.2.4.14 W3F1-98-0040, Request for Additional Information (RAI) Regarding Technical Specification Change Request NPF-38-193 3.2.5 Condition Reports 3.2.5.1 CR-WF3-2012-1395, Wet Cooling Tower Fan Requirements 3.2.5.2 CR-WF3-2012-2332, Cooling Tower Recirculation Assumption 3.2.5.3 CR-WF3-2012-2870, ACC-126A(B) Closing Capability Criteria 3.2.5.4 CR-WF3-2012-3850, Wet Cooling Tower Cross-Connect Errors 3.2.5.5 CR-WF3-2012-3855, MNQ9-10 Not Updated to Reflect New Tornado and New Fuel Pool Cooling Evaluations 3.2.5.6 CR-WF3-2013-883, Damage to top of WCT Fill 3.2.5.7 CR-WF3-2013-1106, Damage to top of WCT Fill 3.2.5.8 CR-WF3-2014-2651, Recirculation Affecting Some DCT Fans More than Others Not Considered In Design 3.2.5.9 CR-WF3-2015-421, DCT Tube Leak 3.2.5.10 CR-WF3-2015-828, DCT Tube Bundle Isolation Valves Not Tested for Leakage 3.2.5.11 CR-WF3-2015-1482, DCT Tube Bundle Isolation Valves Not Tested for Leakage 3.2.5.12 CR-WF3-2015-2117, Design Assumptions Regarding Post Tornado Heat Loads Not Supported by Proceduralized Actions 3.2.5.13 CR-WF3-2015-2503, Tornado Case in MNQ9-2 CCW Flow Analysis Does Not Use Degraded Pump Curve 3.2.6 Work Orders and Test Reports 3.2.6.1 SFG-36-001, Wet and Dry Tower Performance Evaluation 3.2.6.2 MAI 406137, Calibrate CC ITE7075B / CC ITE7076B 3.2.6.3 WO-12709, Thermal Performance Test on WCT A EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 52 OF 119 3.2.6.4 WO-12724, Thermal Performance Test on WCT B 3.2.6.5 WO-14176, Thermal Performance Test on WCT and CCW HX B 3.2.6.6 WO-41082, Thermal Performance Test on Train B Wet Cooling Tower 3.2.6.7 WO-144200, Thermal Performance Test on Train A Wet Cooling Tower 3.2.6.8 WO-186585, Thermal Performance Test on CCW HX B 3.2.6.9 WO-50576, CCW / ACCW Train A Flow Balance 3.2.6.10 WO-247369, CCW / ACCW Train A Flow Balance 3.2.6.11 WO 247374 - April 2011 - Train B - documents an average of 1,382.1 gpm through the CFCs and 3,096.8 gpm through the SDC HX.

3.2.6.12 WO-50231938, Calibrate CC ITE7075A / CC ITE7076A 3.2.6.13 WO 52368665 - December 2012 - CCW / ACCW Train A Flow Balance -

documents an average of 1,398 gpm through the CFCs and 3,003.5 gpm through the SDC HX.

3.2.6.14 WO 52363706 - November 2012 - Train B - documents an average of 1,347.5 gpm through the CFCs and 3,034 gpm through the SDC HX.

3.2.6.15 WO 52480812, Perform CC/ACC Train B Flow Balance Per PE-004-024 3.2.6.16 WO 52476425, Perform CC/ACC Train A Flow Balance Per PE-004-024 3.2.6.17 WO 74223 - WF3 Spent Fuel Pool Cooler - Summer 2006 - Tube Map shows six plugged tubes in the FPC HX.

3.2.6.18 WO 74223, EOI WF3 Spent Fuel Pool Cooler - Summer 2006 - Tube Map shows six plugged tubes in the FPC HX 3.2.6.19 WO 00186585 predicts CCW HX performance at design conditions with 95%

confidence with fouling factors applied only to the shell side of 0.00047 hr-ft2-

°F/BTU for CCW HX A 3.2.6.20 WO 00012763 predicts CCW HX performance at design conditions with 95%

confidence with fouling factors applied only to the shell side of 0.00051 hr-ft2-

°F/BTU for CCW HX B 3.2.6.21 WO-52348919, Thermal Performance Test on Train B Wet Cooling Tower 3.2.6.22 WO-52372443, Thermal Performance Test on Train A Wet Cooling Tower 3.2.6.23 Waterford 3 SES Wet Cooling Tower B Capability Summary Report, May 21, 1998, C&A Consulting Services and John Cooper & Associates 3.2.6.24 Waterford 3 SES Wet Cooling Tower A Capability Summary Report, May 21, 1998, C&A Consulting Services and John Cooper & Associates EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 53 OF 119 4.0 Input and Design Criteria 4.1 Design Function and Equipment Operation Criteria 4.1.1 Design Basis Accident - LOCA 4.1.1.1 10CFR50 Appendix A General Design Criterion (GDC) 44 [3.2.3.1] requires:

4.1.1.1.1 A system to transfer heat from structures, systems, and components important to safety, to an ultimate heat sink shall be provided. The system safety function shall be to transfer the combined heat load of these structures, systems and components under normal operating and accident conditions.

4.1.1.1.2 Suitable redundancy in components and features, and suitable interconnections, leak detection, and isolation capabilities shall be provided to assure that for onsite electrical power system operation (assuming offsite power is not available) and for offsite electrical power system (assuming onsite power is not available) the system safety function can be accomplished, assuming a single failure.

4.1.1.2 NUREG-0800 - Standard Review Plan [3.2.3.2], Section 9.2.5, Ultimate Heat Sink provides acceptance criteria for the design of the UHS. It states that the design of the UHS is acceptable if the system and the associated complex of water sources, including retaining structures and canals or conduits connecting the sources with the station, are in accordance with the following criteria:

4.1.1.2.1 10CFR50 Appendix A, General Design Criterion (GDC) 2 [3.2.3.1], as related to structures housing the system and the system itself being capable of withstanding the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, and floods. Acceptance is based on meeting the guidance of Regulatory Guide 1.29, Position C-1 [] and Regulatory Guide 1.27, Positions C-2 and C-3. [3.2.3.3]

4.1.1.2.1.1 Regulatory Guide 1.29 (Seismic Design) is not evaluated by this calculation.

4.1.1.2.2 GDC 5 [3.2.3.1], as related to shared systems and components important to safety being capable of performing required safety functions.

4.1.1.2.3 GDC 44 [3.2.3.1], as related to:

4.1.1.2.3.1 The capability to transfer heat loads from safety-related structures, systems, and components to the heat sink under both normal operating and accident conditions.

4.1.1.2.3.2 Suitable component redundancy so that safety functions can be performed assuming a single active component failure coincident EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 54 OF 119 with a LOOP.

4.1.1.2.3.3 The capability to isolate components, systems, or piping if required so that safety functions are not compromised.

4.1.1.2.3.4 Acceptance is based upon meeting the guidance of Regulatory Guide 1.27 [3.2.3.3], Positions C-2 and C-3 and Regulatory Guide 1.72, Positions C-1, C-4, C-5, C-6, and C-7, as well as Branch Technical Position ASB 9-2 [3.2.3.2.2].

4.1.1.2.3.5 RG 1.72, Spray Pond Piping Made from Fiberglass Reinforced Thermosetting Resin is not applicable to Waterford 3.

4.1.1.2.4 GDC 45 [3.2.3.1], as related to the design provisions to permit inservice inspection of safety-related components and equipment.

4.1.1.2.5 GDC 46 [3.2.3.1], as related to the design provisions to permit operation functional testing of safety-related systems or components.

4.1.1.3 Regulatory Guide 1.27, Rev. 2 [3.2.3.3] provides the regulatory position that the UHS should be capable of providing sufficient cooling for at least 30 days to ensure that design basis temperatures of safety-related equipment are not exceeded.

4.1.1.3.1 RG 1.27 [3.2.3.3] specifies that the UHS has two principal safety functions: (1) dissipation of residual heat after reactor shutdown, and (2) dissipation of residual heat after an accident.

4.1.1.3.2 In summary, RG 1.27 [3.2.3.3] requires the UHS to provide cooling for at least 30 days, where design basis temperatures of safety-related equipment are not exceeded. Meteorological conditions evaluated should be the worst combination of controlling parameters. For evaporation and drift losses, use the 30 day average combination of controlling parameters. For cooling, use the worst combination of controlling parameters, including diurnal variations where appropriate, for the critical time periods. The following are acceptable methods for selecting these conditions:

4.1.1.3.2.1 Select the most severe observation for the critical time period for each controlling parameter or parameter combination, based on at least 30 years of representative data, with substantiation of the conservatism of these values for site use.

4.1.1.3.2.2 Select the most severe combination of controlling parameters, including diurnal variations where appropriate, for the total of the critical time periods, based on at least 30 years of representative data. If significantly less than 30 years of representative data are available, other historical regional data should be examined to determine the controlling conditions.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 55 OF 119 4.1.1.3.3 Less severe meteorological conditions may be assumed when it can be demonstrated that the consequences of exceeding lesser design basis conditions for short time periods are acceptable. Information on magnitude, persistence, and frequency of occurrence of controlling meteorological parameters that exceed the design basis conditions, based on acceptable data as discussed above, should be presented.

4.1.1.4 W3-DBD-4, Rev. 303 [3.1.2.4] defines the Ultimate Heat Sink at Waterford 3:

The UHS is that heat sink which as sufficient capacity to dissipate to the atmosphere the heat removed from the reactor and its auxiliaries during all modes of operation and during postulated accident conditions. The UHS consists of the dry and wet cooling towers and the water stored in the wet cooling tower basins.

4.1.2 Design Basis Accident - Non-LOCA - Cold Shutdown Capability Criteria 4.1.2.1 NUREG 0800 BTP 5-4 [3.2.3.2.1] requires that the design shall be such that the reactor can be taken from normal operating conditions to cold shutdown

(<200°F) using only safety-grade systems, assuming a single failure, in a reasonable period of time. Limited operator action outside the control room is acceptable if suitably justified for Class 2 plants.

4.1.2.2 RG 1.27 [3.2.3.3], including the requirement to provide cooling for at least 30 days, also applies to plant shutdown events as described in [4.1.1.3] above.

4.1.3 Design Basis Tornado 4.1.3.1 The design basis tornado analysis provides a coping strategy to compensate for potential damage to safety related components that are not protected by missile shielding, which includes 40% of the DCT cells and all of the WCT fans. [3.1.2.4, 3.1.5.8]

4.1.3.2 RG 1.27 [3.2.3.3] states that a cooling capacity of less than 30 days may be acceptable if it can be demonstrated that replenishment or use of an alternate water supply can be effected to assure the continuous capability of the sink to perform its safety functions, taking into account the availability of replenishment equipment and limitations that may be imposed on "freedom of movement" following an accident or the occurrence of severe natural phenomena.

4.1.4 Full Core Offload 4.1.4.1 Section 9.1.3.III.1.d of NUREG 800 [3.2.3.2], states, For the maximum normal heat load with normal cooling systems in operation, and assuming a VLQJOHDFWLYHIDLOXUHWKHWHPSHUDWXUHRIWKHSRROVKRXOGEHNHSW)DQG

the liquid level in the pool should be maintained. For the abnormal maximum heat load (full core unload [soon after previous refueling]) the temperature of the pool water should be kept below boiling and the liquid level maintained with normal systems in operation. A single active failure need not be EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 56 OF 119 considered for the abnormal case.

4.2 Meteorological Inputs 4.2.1 Ambient Temperature 4.2.1.1 In accordance with the guidance in RG 1.27, Rev. 2, [3.2.3.3] meteorological conditions are selected with respect to the controlling parameters and critical time periods unique to the design of each heat sink. For example, the highest recorded dry bulb temperature on the order of one hour is the controlling parameter for the DCT. The highest wet bulb temperature corresponding to the selected dry bulb temperature would be the appropriate controlling parameter for the WCT for the evaluation.

4.2.1.2 The original licensing of Waterford Unit 3 involved an extensive site meteorological assessment that is summarized in Chapter 2 of the Final Safety Analysis Report (FSAR) [3.1.5.5]. Particular emphasis is given to the UHS temperature parameters and atmospheric design parameters that are reported in Chapter 9 of the FSAR [3.1.5.8].

4.2.1.3 Based on study calculations MNQ9-52 [3.2.1.15], Letters ES-LOU-1-76

[3.2.4.8] and ES-LOU87-77 [3.2.4.10], and ES-LOU-91-77 [3.2.4.11], ECM03-007 [3.2.1.5], and supported by Engineering Reports WF3-ME-15-00011, (LPI Report No. A13326-R-001) [3.1.4.2], and WF3-ME-16-00001 [3.1.4.8], the bounding meteorological parameters for design based on historical data and the licensing basis are:

Bounding Average Inlet Temperature Critical Time Period Dry Bulb, °F Wet Bulb, °F One Hour 102 / 98 / 92 78 / 83 / 86*

One Day 92 77*

Three Day 89 76*

Seven Day 86 78*

based on maximum dry bulb / wet bulb combination [3.1.4.8]

4.2.1.3.1 Engineering Report WF3-ME-16-00001 [3.1.4.8] develops a bounding relationship between ambient wet bulb and ambient dry bulb temperatures for each critical time period. Lower wet bulb temperature for a given dry bulb is associated with lower relative humidity, which increases the evaporation rate for the WCT.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 57 OF 119 Critical Time Bounding Average Wet Bulb vs Dry Bulb Temperature Period One Hour High: For Tdb d 85q F , Twb (Tdb ) Tdb For 85q F Tdb d 92q F , Twb (Tdb ) 85q F For 92q F Tdb d 98q F , Twb (Tdb ) (1 / 3)Tdb 115.67q F )

For 98q F Tdb d 102q F , Twb (Tdb ) (5 / 4)Tdb 205.5q F )

Low: Twb (Tdb ) Tdb 24q F )

One Day High: For Tdb d 83q F , Twb (Tdb ) Tdb For 83q F Tdb d 84q F , Twb (Tdb ) 83q F For 84q F Tdb d 88q F , Twb (Tdb ) (1 / 4)Tdb 104q F )

For 88q F Tdb d 92q F , Twb (Tdb ) ( 5 / 4)Tdb 192q F )

Low: Twb (Tdb ) Tdb 15q F )

Three Day High: For Tdb d 83q F , Twb (Tdb ) Tdb For 83q F Tdb d 84q F , Twb (Tdb ) 83q F For 84q F Tdb d 88q F , Twb (Tdb ) (1 / 4)Tdb 104q F )

For 88q F Tdb d 89q F , Twb (Tdb ) (6)Tdb 610q F )

Low: Twb (Tdb ) Tdb 13q F )

Seven Day High: For Tdb d 80q F , Twb (Tdb ) Tdb For 80q F Tdb d 82q F , Twb (Tdb ) (1 / 2)Tdb 40q F For 82q F Tdb d 85q F , Twb (Tdb ) 81q F )

For 85q F Tdb d 86q F , Twb (Tdb ) (3)Tdb 336q F )

Low: Twb (Tdb ) Tdb 11q F )

based Report WF3-ME-16-00001 [3.1.4.8]

4.2.2 Other Meteorological Parameters and Parameter Relationships 4.2.2.1 The relationship between other meteorological parameters and ambient dry bulb temperature is evaluated in Engineering Report WF3-ME-16-00001

[3.1.4.8]. The report supports establishing the following bounding relationships for recirculation effect and DCT fan flow rate vs ambient dry bulb temperature:

4.2.2.1.1 The recirculation effect is related to wind speed and the number of DCT fans out-of-service that could allow backflow to the suction of the operating fans. The suction areas of the individual DCT fans are not separated. Engineering Report WF3-ME-15-00014, (LPI Report No.

A14386-R-001), [3.1.4.5], identifies that DCT fans that are not running and EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 58 OF 119 are not covered to prevent backflow may increase overall recirculation by as much as 3°F per uncovered-out-of-service fan. WF3-ME-15-00014 also establishes bounding recirculation as a function of wind speed.

Engineering Report WF3-ME-16-00001 [3.1.4.8] establishes a bounding relationship between wind speed and ambient dry bulb temperature and provides a Mathcad worksheet that can be used to determine a bounding recirculation effect for any given dry bulb temperature and number of fans allowing backflow.

4.2.2.1.2 The relationship between DCT fan flowrate and wind speed is evaluated in Engineering Report WF3-ME-15-00014, (LPI Report No. A14386-R-001)

[3.1.4.5]. WF3-ME-15-00014 also establishes a bounding low DCT fan flow rate as a function of wind speed. Engineering Report WF3-ME 00001 [3.1.4.8] establishes a bounding relationship between wind speed and ambient dry bulb temperature and Engineering Report WF3-ME 00013 (LPI Report No. A13326-R-003) [3.1.4.4] provides a Mathcad worksheet that determines a bounding low DCT fan flowrate for any given dry bulb temperature.

4.3 Heat Load Inputs 4.3.1 Cooling Loads - General:

4.3.1.1 W3-DBD-4 [3.1.2.4], describes the cooling loads. Each train of the safety related essential loop services the following equipment:

x two containment fan coolers - containment heat x one shutdown cooling heat exchanger - containment heat x one emergency diesel generator - auxiliary heat x one essential services water chiller - essential chiller heat x one high pressure safety injection pump - auxiliary heat x one low pressure safety injection pump - auxiliary heat x one containment spray pump - auxiliary heat x the Post Accident Sampling System (PASS) - auxiliary heat 4.3.1.2 The nonessential seismically qualified loop services the following equipment:

x one fuel pool heat exchanger - fuel pool heat x one backup fuel pool heat exchanger - fuel pool heat x one letdown heat exchanger - normal operations x four reactor coolant pump seals and motor coolers - normal operations x control element drive mechanism (CEDM) coolers - normal operations 4.3.1.3 The nonessential non-seismic loop services the following equipment:

x waste gas compressors - normal operations EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 59 OF 119 x sample coolers - normal operations x chemical feed tank - normal operations x boric acid and waste concentrators - normal operations 4.3.2 Auxiliary Heat Loads 4.3.2.1 Emergency Diesel Generator (EDG) 4.3.2.1.1 Rated EDG load is 4,800 kW based on drawings 5817-9376 and 1564-1998 and the associated heat load is 9,705,000 BTU/hr. [3.1.3.2, 3.1.3.17]

4.3.2.1.2 ECE90-006 [3.1.1.19 (pdf page 189 of 207)] shows the diesel loading for various times for shutdown and accident conditions.

4.3.2.1.2.1 ECE90-006 [3.1.1.19] shows the EDG is loaded a maximum of 75%

for a shutdown. Therefore, based on the heat load to electrical load relationship shown in [5.9], EDG shutdown heat load is 75%

9,705,000 BTU/hr = 7,278,750 BTU/hr.

4.3.2.1.2.2 ECE90-006 [3.1.1.19] shows the EDG loading for greater than 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months after shutdown is 3291 kW. Therefore, based on the heat load to electrical load relationship shown in [5.9], EDG refueling and tornado event after 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months heat load is 9,705,000 BTU/hr

3,291 kW /4,800 kW = 6,650,000 BTU/hr.

4.3.2.2 Emergency Core Cooling System (ECCS) Pumps 4.3.2.2.1 ECM97-001 [3.1.1.41] shows that the design criteria used for the heat loads from the HPSI and LPSI pumps are conservative. The actual heat load is approximately 23,000 BTU/hr with 115°F cooling water.

4.3.2.2.2 ECM97-028 [3.1.1.44] shows that the design criteria used for the heat loads from the CS pumps are conservative. The actual heat load is approximately 2,400 BTU/hr.

4.3.3 Essential Chiller Heat Loads 4.3.3.1 9C2-5Y [3.1.1.7], concludes that the maximum heat rejected by the Essential Chillers for the following events:

4.3.3.1.1 LOCA / Accident - 4.3x106 Btu/hr 4.3.3.1.2 Shutdown - 3.4x106 Btu/hr 4.3.3.1.3 Tornado -4.2x106 Btu/hr 4.3.3.1.4 Normal Operation - 5.3 x 106 BTU/hr (two trains) 4.3.3.1.5 Normal Shutdown - 6.2 x 106 BTU/hr (two trains) 4.3.3.1.6 See assumptions for other events.

4.3.3.2 9C2-5Y [3.1.1.7] provides actual chiller performance test results that can be EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 60 OF 119 used to calculate efficiency at various operating points.

4.3.4 Fuel Pool Heat Loads 4.3.4.1 General Spent Fuel Pool Cooling Heat Load Inputs 4.3.4.1.1 ECM98-067 [3.1.1.45], determines the spent fuel pool heat loads for various configurations.

4.3.4.1.2 Branch Technical Position ASB 9-2 [3.2.3.2.2] Rev2 - July 1981 provides acceptable assumptions and formulations that may be used to calculate the residual decay energy release rate for light-water-cooled reactors for long-term cooling of the reactor facility. The following inputs are used to compute the decay heat load.

4.3.4.1.2.1 NPF-38, Waterford 3 Operating License [3.1.5.1] shows the core thermal power limit is 3716 MW.

4.3.4.1.2.2 ECI01-002 [3.1.1.22] concludes that power measurement uncertainty is limited to 0.5%.

4.3.4.1.2.3 NUREG 0800 BTP ASB 9-2 [3.2.3.2.2] states: An operating history of 16,000 hours0 days 0 hours 0 weeks 0 months is considered to be representative of many end-of-first or equilibrium cycle conditions and is, therefore, acceptable. In calculating the fission product decay energy, a 20% uncertainty factor K should be added for any cooling time less than 103 seconds, and a factor of 10% should be added for cooling times greater than 103 seconds but less than 107 seconds.

4.3.4.1.2.4 ECM98-067 justifies that the bounding average assembly operating time, at the end of a cycle, is 1.7

544 days for a full core and 2.2

544 days for the part of the core that is stored in the spent fuel pool.

4.3.4.2 Non-Refueling Spent Fuel Pool Heat 4.3.4.2.1 ECM98-067 [3.1.1.45] uses BTP ASB 9-2 methodology and concludes:

4.3.4.2.1.1 The bounding fuel pool heat load with 108 freshly added fuel assemblies is 16.4 MBTU/hr 25 days after shutdown.

4.3.4.2.1.2 The bounding number of fuel assemblies remaining in the SFP after an outage is 108.

4.3.4.2.1.3 The bounding background decay heat from previously stored assemblies prior to a normal refueling outage is 5.326 x 106 BTU/hr based on 2104 assemblies in fuel pool where plant is started after the refueling outage.

4.3.4.2.1.4 The shortest refueling outage to date was RF-12, which was 25 days breaker-to-breaker.

4.3.4.2.1.5 The mass of water in the spent fuel pool is 2,849,099 lbm.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 61 OF 119 4.3.4.3 Refueling Spent Fuel Pool Heat Loads 4.3.4.3.1 Core Shuffle 4.3.4.3.1.1 Calculation ECM98-067 [3.1.1.45] concludes that the bounding design basis FPC heat load for a core shuffle is 29,930,000 BTU/hr, assuming that the core offload commences 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months after shutdown and completes 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months later.

4.3.4.3.1.2 TS 3.9.3 requires the reactor to be subcritical for at least 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months during movement of irradiated fuel in the reactor pressure vessel and with the reactor subcritical for less than 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , suspend all operations involving movement of irradiated fuel in the reactor pressure vessel.

4.3.4.3.2 Full Core Offload 4.3.4.3.2.1 Calculation ECM98-067 [3.1.1.45] concludes that the bounding design basis FPC heat load is 43,568,000 BTU/hr, assuming that core offload commences 120 hours0.00139 days 0.0333 hours 1.984127e-4 weeks 4.566e-5 months after shutdown and completes 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months later based on an offload rate of 6 assemblies per hour.

ECM98-067 provides additional FPC heat loads for various times after reactor shutdown. ECM98-067 determines the decay heat using BTP ASB 9-2 [3.2.3.2.2] methodology.

4.3.4.3.3 Abnormal FPC Heat Load 4.3.4.3.3.1 ECM98-067 [3.1.1.45] determines that the abnormal FPC heat load is 50,395,000 BTU/hr, assuming that core offload commences 150 hours0.00174 days 0.0417 hours 2.480159e-4 weeks 5.7075e-5 months after shutdown with the previous spent fuel batch stored for only 36 days since the previous shutdown.

4.3.4.3.3.2 The bounding maximum previously stored fuel heat load prior to abnormal core offload where the previous batchs decay was 36 days is 14,105,000 BTU/hr [3.1.1.45].

4.3.5 Containment Heat Loads 4.3.5.1 LOCA Containment Heat Loads 4.3.5.1.1 ECS05-013 [3.1.1.46] tabulates bounding time dependent (transient) containment heat load for bounding LOCA conditions for several CCW supply temperatures. The tables are duplicated in the mathematical model used in this analysis. ECS05-013 calculates the heat transferred by the CFC and the SDC HX to CCW for the LBLOCA. Heat loads are calculated for two bounding cases, a hot leg guillotine break and a RCP discharge line break.

4.3.5.1.1.1 ECS05-013 uses CFC and SDC HX performance data from ECS96-015 [3.1.1.49] and MNQ9-1 [3.1.1.52] with zero fouling to EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 62 OF 119 maximize the heat transferred to the UHS.

4.3.5.1.1.2 The hot leg guillotine break results in the highest peak containment heat load, but that peak is so early in the event (1.8 to 70 seconds) as to make it insignificant for determining the capability of the UHS.

See assumption [5.1.6].

4.3.5.1.1.3 The DEDLSB results in the highest total integrated heat load and the highest peak heat load of significance for analyzing the capacity of the UHS cooling towers and heat exchangers. See assumption

[5.1.6].

4.3.5.1.1.4 The DEDLSB results in the highest containment heat load at about 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months into the event when the water from the Safety Injection Sump is pumped through the SDC HX, with a smaller peak 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months into the event when FPC would be restored. See assumption

[5.1.6].

4.3.5.1.1.5 Containment heat loads resulting from a LBLOCA mass and energy release were determined by ECS05-013 for three CCW temperatures: 112°F, 115°F, and 120°F to allow interpolation and establishing a relationship between containment heat load and CCW supply temperature. The heat transferred to CCW from containment is a function of CCW supply temperature. [3.1.1.46]

4.3.5.1.1.6 ECS05-013 provides a study case that shows that the heat load is approximately 5.5% higher for the duration of the LOCA event because using the upper bound decay heat fractions and another 0.5% higher because of plant power uncertainty.

4.3.5.1.1.7 If running the CEDM fans, added motor heat is less than 1.3 MBTU/hr per 2-D [3.1.1.2], which is less than 1% of peak containment heat load.

4.3.5.2 Non-LOCA Accident, Tornado, and Shutdown Containment Heat Loads 4.3.5.2.1 Decay heat removal and RCS cool down for a natural circulation cooldown are initially accomplished by EFW until SDC entry conditions are reached.

Calculation CN-SEE-II-09-21 [3.1.1.14] provides input for EFW water consumption and time to reach SDC entry conditions (350°F).

4.3.5.2.2 CN-SEE-II-08-6 [3.1.1.13], provides the transient shutdown cooling heat load for four analyzed cases.

4.3.5.2.2.1 Normal Cooldown - Two Trains SDC 4.3.5.2.2.2 Normal Cooldown - Single Train of SDC 4.3.5.2.2.3 Natural Circulation Cooldown - Failed ADV: 40°/hr cooldown 4.3.5.2.2.4 Natural Circulation Cooldown - Failed EDG: 40°/hr cooldown EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 63 OF 119 4.3.5.2.2.5 This analysis will consider the two limiting natural circulation cases for a failed EDG and a failed ADV.

4.3.5.2.3 Calculation CN-SEE-II-08-6 [3.1.1.13] outputs bounding time dependent heat loads on the SDC HX for cooling the RCS from conditions for various CCW supply temperatures and assumed cooldown rates. The normal shutdown case containment peak heat load on the UHS is 204.1 x 106 BTU/hr.

4.3.5.2.4 Branch Technical Position ASB 9-2 [3.2.3.2.2] Rev2 - July 1981 provides acceptable assumptions and formulations that may be used to calculate the residual decay energy release rate for light-water-cooled reactors for long-term cooling of the reactor facility. The following inputs are used to compute the decay heat load in accordance with BTP ASB 9-2 from NUREG-0800 [3.2.3.2.2].

4.3.5.2.4.1 NPF-38, Waterford 3 Operating License [3.1.5.1] shows the core thermal power limit is 3716 MW.

4.3.5.2.4.2 ECI01-002 [3.1.1.22], concludes that power measurement uncertainty is limited to 0.5%.

4.3.5.2.4.3 BTP ASB 9-2 [3.2.3.2.2] states: An operating history of 16,000 hours0 days 0 hours 0 weeks 0 months is considered to be representative of many end-of-first or equilibrium cycle conditions and is, therefore, acceptable. In calculating the fission product decay energy, a 20% uncertainty factor K should be added for any cooling time less than 103 seconds, and a factor of 10% should be added for cooling times greater than 103 seconds but less than 107 seconds.

4.3.5.2.4.4 ECM98-067 justifies that the bounding average assembly operating time, at the end of a cycle, is 1.7

544 days for a full operating core.

4.3.5.2.5 W3-DBD-9 [3.1.2.5], W3-DBD-1 [3.1.2.1], CN-SEE-II-09-21 [3.1.1.14],

ECM89-004 [3.1.1.39] and ECS98-013 [3.1.1.50] provide conservative sensible heat removal inputs:

4.3.5.2.5.1 Cold Shutdown RCS temperature - 200°F 4.3.5.2.5.2 SDC entry RCS temperature - 350°F 4.3.5.2.5.3 Normal operating RCS temperature - 610°F (conservative) 4.3.5.2.5.4 Normal operating RCS pressure - 2250 psia 4.3.5.2.5.5 Volume of Water in RCS - 10485 ft3 + 1519 ft3 4.3.5.2.5.6 Mass of Metal in RCS - 1892844 lbm + 1376509 lbm 4.3.5.2.5.7 Specific Heat of RCS Metal - 0.1371 BTU/lbm R EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 64 OF 119 4.3.5.2.5.8 Mass of Fuel - 259983 lbm 4.3.5.2.5.9 Mass of non-fuel core - 83215 lbm 4.3.5.2.5.10 density of core - 10.31 gm/cm3 4.3.5.2.5.11 specific heat of fuel - 1 BTU/ft3 R 4.3.5.2.6 If running the CEDM fans, added motor heat is less than 1.3 MBTU/hr per 2-D [3.1.1.2], which is less than 1% of peak containment heat load.

4.3.5.3 Normal Operation Containment Heat Loads 4.3.5.3.1 1-B [3.1.1.1] concludes that the normal operating heat load on the Containment Fan Coolers is 4.66 x 106 BTU/hr.

4.3.6 Miscellaneous Non-Safety Related Equipment Heat Loads 4.3.6.1 Reactor Coolant Pumps 4.3.6.1.1 Normal Operation - 10,080,000 BTU/hr per C-CE-9709 [3.2.4.6]

4.3.6.1.2 Normal Shutdown - 5,040,000 BTU/hr per C-CE-9709 [3.2.4.6]

4.3.6.2 Letdown Heat Exchanger 4.3.6.2.1 Normal Operation - 19,920,000 BTU/hr per C-CE-9709 [3.2.4.6]

4.3.6.2.2 Normal Shutdown - 3,000,000 BTU/hr per C-CE-9709 [3.2.4.6]

4.3.6.3 Control Element Drive 4.3.6.3.1 Normal Operation - 4,000,000 BTU/hr per 2-D [3.1.1.2]

4.3.6.3.2 Normal Shutdown - 4,000,000 BTU/hr per 2-D [3.1.1.2]

4.3.6.4 Waste Gas Compressors 4.3.6.4.1 Normal Operation - 50,000 BTU/hr per C-CE-9709 [3.2.4.6]

4.3.6.4.2 Normal Refueling - 50,000 BTU/hr per C-CE-9709 [3.2.4.6]

4.3.6.5 Sample Coolers 4.3.6.5.1 Normal Operation - 2,500,000 BTU/hr per 457001250 V1 [3.1.9.10]

4.3.6.6 Boric Acid and Waste Concentrators 4.3.6.6.1 Normal Operation - 23,400,000 BTU/hr per C-CE-135 [3.2.1.3]

4.4 Water Temperature and Flow Inputs 4.4.1 Cooling Flow - General 4.4.1.1 MNQ9-2 [3.1.1.53] determines achievable CCW flow rates to cooled components and to the DCT and CCW HX for various lineups. This includes accident, shutdown, and normal lineups, and when a DCT tube bundle may be isolated for maintenance.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 65 OF 119 4.4.1.2 MNQ9-65 [3.1.1.57] conservatively assumes reduced CCW flow, lower than those calculated in MNQ9-2 [3.1.1.53], during accident conditions in order to maximize CCW piping temperatures downstream of components.

4.4.1.3 The table below summarizes the bounding flow through the DCT and CCW HX for each analyzed event:

Event Bounding CCW Flow Rate, gpm LOCA 6,900 Non-LOCA Accident 6,900 Tornado 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months 3,680 Tornado 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months 3,394 Tornado - 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months to SDC 4,063 Tornado - post SDC 5,389 Full Core Offload 7,377 Normal Shutdown 6,800 / train Normal Refueling 6,100 / train Normal Operation 6,000 / train 4.4.2 LOCA 4.4.2.1 The CCW Flow Balance Surveillance procedure, PE-004-024 [3.1.6.18], has a maximum CCW flow rate limit in the accident alignment of < 6900 gpm.

The minimum CCW flow rate through the CCW HX in the accident lineup is 6028 gpm, determined in MNQ9-2. Surveillance procedure PE-004-024

[3.1.6.18], requires total system flow through the LOCA lineup to be at least 6082.5 gpm. Higher CCW flow rates minimize DCT inlet temperature and the heat transfer by the DCT based on conservation of energy and also minimize water inventory margin. Therefore, using the highest allowable flowrate of 6900 gpm is conservative.

4.4.2.2 In the event of a SIAS, the four pump suction header valves (CC 114A(B), CC 115A(B), the four pump discharge header valves (CC 126A(B), CC 127A(B),

and train isolation valves (CC 563, CC 200B) all close. These valve closings separate the two safety related trains A and B. In addition, the SIAS closes valves CC 562 and CC 501, which isolate the non-essential non-seismic loop from the safety related components. Reference W3-DBD-4 [3.1.2.4].

4.4.2.3 In the event of a Containment Spray Actuation Signal (CSAS), the non-essential loop isolation valves (CC-727, CC-200A) close, leaving two independent safety related cooling trains. Reference W3-DBD-4 [3.1.2.4]

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 66 OF 119 4.4.3 Design Basis Tornado 4.4.3.1 Lo-Lo Level in the CCW Surge Tank causes train separation. [3.1.2.4]

4.4.4 CCW Supply Temperature Setpoint 4.4.4.1 LOCA - 117.4°F based on the following:

4.4.4.1.1 Upon an accident condition signal (SIAS), the setpoint for CCW supply temperature control increases to 117.4°F for water inventory conservation.

Higher CCW temperature increases the temperature differential for the DCT and shifts more heat duty to the DCT. When a SIAS occurs, the setpoint for the temperature exiting the CCW HX is automatically raised from 90°F to 117.4°F provided wet tower basin temperature is >74°F.

Reference B425 sheets T7075A1, T7075A2, T7075B1, and T7075B2.

[3.1.3.37, 3.1.3.38, 3.1.3.39, 3.1.3.40]

4.4.4.1.2 DCT fans start in high speed and ACC-126A(B) throttles to control CCW supply temperature at 117.4°F based on calculation ECI91-036 [3.1.1.27].

The calculated uncertainty is +/-2.6°F.

4.4.4.1.2.1 CC ITE7075A(B) and CC ITE7076A(B) calibration records in WO 5231938 (MAI406137) [3.2.6.12 ,3.2.6.2] show that the accuracy of the thermocouple is within 0.6°F, which, if credited, would significantly lower the uncertainty of the water temperature control function.

4.4.4.1.3 The lower setpoint uncertainty will be reduced to account for containment heat load uncertainty that is built into the results of ECS05-013 [3.1.1.46].

The upper bound decay heat fractions are used to determine the containment heat load, which adds more than 5.5% to the heat load for the entire transient. In addition, plant power uncertainty of 0.5% is assumed. Therefore, for the purpose of evaluating UHS margins, the CCW setpoint tolerance should be considered only 1.1°F, if the entire uncertainty for the containment heat loads is taken. This is equivalent to using the square-root-of-the-sum-of-the-squares (SRSS) method of combining uncertainties per DEIC-I-502 [3.1.6.21]. Attachment [8.1.8]

provides more details. [4.3.5.1.1.6]

4.4.4.2 Non-LOCA Accident 4.4.4.2.1 Normally, CCW supply temperature is maintained less than 102°F to prevent the chiller coolant from switching to WET TOWER mode. CCW supply temperature should be maintained less than 102°F to prevent Essential Chiller coolant from swapping from DRY TOWER to WET TOWER mode and so as not to challenge spent fuel pool temperature limits. However, during bounding meteorological conditions, and because RCS cooldown rate after SDC affects CCW supply temperature, maintaining CCW supply temperature below 102°F may not be possible.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 67 OF 119 RCS cooldown rate should be controlled to limit heat load from the SDC HX. CCW supply temperature also affects Spent Fuel Pool temperature, especially if CCW to the FPC HX is throttled to prevent starving other components. Operator action is credited to isolate and throttle CCW to the FPC HX and raise CCW supply temperature to 117.4°F prior to initiating SDC for Non-LOCA accidents with only one train of UHS available.

4.4.4.2.2 Calculation ECM98-067 [3.1.1.45] concludes that CCW supply temperature must be limited to 111°F with 2,300 gpm flow rate in order to maintain spent fuel pool temperature below 140°F with bounding operating cycle heat load. Spent fuel pool temperature can be kept less than 180°F with 850 gpm of CCW at 120°F.

4.4.4.3 Full Core Offload - )EDVHGRQ(&0-067 4.4.4.3.1 RF-005-001 [3.1.6.20@GLUHFWVWRPDLQWDLQ&&:VXSSO\WHPSHUDWXUH)

for the design basis full core offload. ECM98-067 [3.1.1.45] provides spent fuel pool heat loads for different core hold times and the associated required CCW supply temperatures for maintaining spent fuel pool temperature within limits.

4.4.5 Auxiliaries 4.4.5.1 Emergency Diesel Generator (EDG) 4.4.5.1.1 5817-9376 [3.1.3.17] and 1564-1998 [3.1.3.2] show that the rated cooling water supply conditions for the EDG Jacket Water HX, and the EDG Lube Oil HX / EDG Air Intercooler are 120°F @ 450 gpm and 350 gpm, respectively. Attachment [8.7.1] of this calculation provides the basis.

4.4.5.1.2 5817-9517 [3.1.3.18] and 1564-2000 [3.1.3.3] illustrate a schematic of the EDG Intake and Exhaust systems. TD-C629.0035, Section 14, Combustion Air System, [3.1.9.3] states that fresh air for combustion is drawn through a filter and silencer by the turbocharger and distributed to the cylinders through intercoolers and heaters and air intake manifolds.

The coolers and heaters are fin-tube type and are mounted directly in the engine air inlet headers downstream of the turbocharger. The Intercooler is a cross-flow / counter-flow heat exchanger with 1 air pass and 2 water passes for hot water and two passes for cold water. The cold water core is the larger of two cores.

4.4.5.1.3 5817-9376 [3.1.3.17] and 1564-1998 [3.1.3.2] illustrate a schematic of the EDG cooling water system. CCW is provided separately to two parallel sets of heat exchangers. 350 gpm of CCW is directed through the Intercoolers and Lube Oil heat exchangers in series. 450 gpm of CCW is directed through the jacket water heat exchanger. The CCW supply temperature was originally designed to be 115°F to the intercooler and EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 68 OF 119 jacket water heat exchanger and 132.4°F to the lube oil heat exchanger.

The heat loads are provided for the EDG producing 4840 kW (110% of design load) with 115 °F cooling water supply. This calculation evaluates raising the CCW supply temperature to 120°F (maximum).

4.4.5.1.4 5817-9519 [3.1.3.20] and 1564-2001 [3.1.3.4] illustrate a schematic of the EDG lube oil system. The schematic shows that the design temperature of the oil into the lube oil heat exchanger is 165 °F to 170 °F based on the setpoint of the temperature control valve. TD-C629.0035 [3.1.9.3] provides a description of the Thermostatic Valve. It states that at 170 °F and above, the oil goes to the cooler. At 160 °F or lower, the oil bypasses the cooler.

The valve will modulate flow between the cooler and bypass to maintain oil temperature at approximately 165 °F.

4.4.5.1.5 TD-C629.0035 [3.1.9.4] states that the lube oil cooler is designed for excess cooling capacity and has a conservative fouling factor. Cooper Bessemer drawing, 2-02H-859, in TD-C629.0015 [3.1.9.3], shows that the Lube Oil HX is a 2 pass TEMA Type AEW shell and tube heat exchanger.

The shell side is designed for oil flowing at 530 gpm with an inlet temperature of 167.5 °F. The tube side is designed for water flowing at 350 gpm with an inlet temperature of 132 °F. The design fouling factor is 0.001 hr*ft2 °F/BTU, which is appropriate for engine oil. The design heat load is 2,112,000 BTU/hr. This is 9% higher than the 1,940,000 BTU/hr heat load shown on 5817-9376 [3.1.3.17] and 1564-1998 [3.1.3.2].

4.4.5.1.6 Cooper Bessemer drawing, 2-02H-858, in TD-C629.0015 [3.1.9.3], shows that the Jacket Water Heat Exchanger is a 2 pass TEMA Type AEW shell and tube heat exchanger. The shell side is designed for Jacket Water flowing at 1080 gpm with an inlet temperature of 170 °F and exit temperature of 161 °F. The tube side is designed for CCW flowing at 450 gpm with an inlet temperature of 115 °F and exit temperature of 135.4 °F.

The design fouling factor is 0.001hr*ft2 °F/BTU on both tube and shell side. This is very high for treated water systems. The design heat load is 4,718,000 BTU/hr.

4.4.5.1.7 Calculation A15503-C-001 [3.1.1.8] develops mathematical models for the EDG Jacket Water and Lube Oil Coolers.

4.4.5.1.8 MNQ9-2 [3.1.1.53] concludes that the design basis flow rates to the EDG components may be less than rated cooling water flow rates (450 Jacket Water and 350 Lube Oil / Intercoolers) and this calculation evaluates the acceptability of the lower cooling water flow rates. [8.7.1]

4.4.5.1.8.1 MNQ9-2 [3.1.1.53] demonstrates that the CCW system is capable of supplying at least 422.6 gpm to the EDG Jacket Water cooler and 348.7 gpm to the EDG Lube Oil / Intercoolers during an accident. This accounts for one DCT tube bundle isolated.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 69 OF 119 4.4.5.1.8.2 For the Full Core Offload case, where CC-620 is fully open, the flow rate to the EDG components may be up to 20% lower than rated cooler water flow rates (363.9/450 = 81% and 302.1/350 = 86%).

However, during full core offload conditions, the CCW supply temperature will be much cooler (<90°F) than the maximum temperature (120°F). The ~35% greater temperature differential more than compensates for the 20% reduction in mass flow rate.

[8.7.1]

4.4.5.1.9 PE-004-024 [3.1.6.18] has flow acceptance criteria for EDG Jacket Water Cooler and EDG Lube Oil HX / EDG Air Intercooler of 475 gpm and 375 gpm, respectively.

4.4.5.2 ECCS Pumps 4.4.5.2.1 High Pressure Safety Injection (HPSI) Pump 4.4.5.2.1.1 ECM97-001 [3.1.1.41] concludes that the required cooling water supply conditions are 115°F @ 10gpm and 120°F @ 12 gpm.

4.4.5.2.1.2 MNQ9-2 [3.1.1.53] concludes that the expected CCW flow to the

+36,SXPSGXULQJDQDFFLGHQWLV14 gpm and during a tornado is 16 gpm.

4.4.5.2.1.3 PE-004-024 [3.1.6.18] has acceptance criteria for HPSI Pump Cooler flow of 13.5gpm.

4.4.5.2.2 Low Pressure Safety Injection (LPSI) Pump 4.4.5.2.2.1 ECM97-001 [3.1.1.41] concludes that the required cooling water supply conditions are 115°F @ 10gpm and 120°F @ 12 gpm.

4.4.5.2.2.2 MNQ9-2 [3.1.1.53] concludes that the expected CCW flow to the

/36,SXPSGXULQJDQDFFLGHQWLV14 gpm and during a tornado is 16 gpm.

4.4.5.2.2.3 PE-004-024 [3.1.6.18] has acceptance criteria for LPSI Pump Cooler flow of 13 gpm.

4.4.5.2.3 Containment Spray (CS) Pump 4.4.5.2.3.1 TD-B015.0025 [3.1.9.2], specifies service water flow of 2.5 gpm at 115°F maximum temperature.

4.4.5.2.3.2 ECM97-028 [3.1.1.44] concludes that only 5 gpm at 120°F maximum temperature provides the required CS pump cooling.

4.4.5.2.3.3 MNQ9-2 [3.1.1.53] concludes that the expected CCW flow to the

&6SXPSGXULQJDQDFFLGHQWLV6.5 gpm and CS is not required for the tornado event.

4.4.5.2.3.4 PE-004-024 [3.1.6.18], has acceptance criteria for CS Pump Cooler EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 70 OF 119 flow of 6 gpm.

4.4.6 Essential Chiller 4.4.6.1 The setpoint for swapping the Essential Chiller coolant supply from DRY TOWER to WET TOWER mode is 102°F +/- 0.5°F (CC ITAC7075-A1 / B1)

Reference B424 sheet 821 - 828 and T7075B2. [3.1.3.37, 3.1.3.38, 3.1.3.39, 3.1.3.40]

4.4.6.2 Calculations 9C2-5Y [3.1.1.7] and 5-T [3.1.1.6] demonstrate that the Essential Chiller is capable of design basis accident performance with condenser cooling water temperature as high as 110°F. Therefore, Essential Chiller cooling may be manually switched to Dry Tower mode when the UHS is capable of maintaining CCW HX outlet temperature less than 110°F. 5-T

[3.1.1.3] shows acceptable Essential Chiller performance with reduced flow rates as low as 750 gpm for lower loads and lower cooling water temperature.

4.4.6.3 MNQ9-2 [3.1.1.53] concludes that the expected CCW flow to the Essential Chillers in all cases where CCW is supplied (CCW 102) LV11 gpm.

611 gpm is associated with a shutdown case where CCW may not reach the 102°F setpoint to switch the chiller to Wet Tower mode. 611 gpm is lower than the 750 gpm evaluated in 5-T [3.1.1.6]. However, based on the large margin (141 tons) determined in the evaluation in 5-T [3.1.1.6] for for the shutdown case with 750 gpm CCW flow at 110°F, 611 gpm is acceptable for the shutdown case with CCW less than 102°F. See MNQ9-2 for more details.

4.4.6.4 MNQ9-50 [3.1.1.56] concludes that the expected ACCW flow to the Essential

&KLOOHUVIRUDQ\FRQGLWLRQZKHUHWKH:(772:(5PRGHLVVHOHFWHGLV

gpm.

4.4.6.5 PE-004-024 [3.1.6.18] has acceptance criteria for Essential Chiller CCW flow in the accident lineup of 850 gpm.

4.4.7 Fuel Pool Cooling Heat Exchangers 4.4.7.1 ECC98-015 [3.1.1.18] qualifies the spent fuel pool for accident temperature up to 212°F.

4.4.7.2 ECM98-067 [3.1.1.45] demonstrates that the Fuel Pool Heat Exchanger is capable of maintaining the Spent Fuel bulk temperature less than 180°F with less than 825 gpm of CCW supplied at 120°F.

4.4.7.3 MNQ9-2 [3.1.1.53] concludes that acceptable CCW flow rates to essential components are achievable after lining up Fuel Pool Cooling with CCW flow at a rate 850 gpm, which would maintain 180°F in the Spent Fuel Pool after a design basis accident or tornado.

4.4.7.4 MNQ9-2 [3.1.1.53] concludes that the minimum single pump CCW flow rates assuming a fully open FPC HX temperature control valve and other CCW loads, including EDG, operating as designed are:

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 71 OF 119 4.4.7.4.1 FPC HXs - CC-620 at 100%

4.4.7.4.1.1 Single FPC HX flow = 4061 gpm 4.4.7.4.1.2 Parallel FPC HXs 4.4.7.4.1.2.1 FPC HX Flow = 2755 gpm 4.4.7.4.1.2.2 BUFPC HX Flow = 1745 gpm 4.4.8 Containment Fan Coolers (CFC) and Shutdown Cooling Heat Exchangers (SDCHX) 4.4.8.1 1-B [3.1.1.1] uses a 670 gpm CCW flow rate to the CFC to determine the performance capacity during normal operation.

4.4.8.2 Calculation ECS98-015, Revision 2, [3.1.1.51] evaluates acceptable containment LOCA response with 115°F and 120°F CCW supply temperature with 1100 gpm to the Containment Fan Coolers and 2550 gpm to the SDC HX.

4.4.8.3 ECS98-015 Revision 2, (ECN40132, dated 11/19/12, and EC-50235, dated 4/9/14) [3.1.1.51], concludes that containment peak pressure and temperature and the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months temperature and pressure for the analyzed Loss of Coolant Accidents and Main Steam Line Break are within the acceptance criteria with CCW supplied at 120°F and 1100 gpm to the CFC and 120°F and 2550 gpm to the SDCHX. MNQ9-2 [3.1.1.53] and PE-004-024 [3.1.6.18]

demonstrate that the CCW flow to the SDCHX is at least 2800 gpm and that CCW flow to the CFC is at least 1200 gpm. Reduced flows for certain events are justified in MNQ9-2.

4.4.8.4 The sensitivity cases from ECS05-013 [3.1.1.46] provide appropriate input for determining the heat load on the CCW system based on using heat transfer data for bounding performance parameters and a given CCW supply temperature. Heat transfer from the CFC and SDC HX is higher for higher CCW flow rates. The sensitivity cases are developed using an average CCW flow rate of 1,350 gpm to two CFCs and 3,200 gpm to the SDC HX (5,900 gpm total). MNQ9-2 [3.1.1.53] concludes that the expected accident CFC flow rate will be an average of < 1330 gpm and that the SDC HX flow rate will be < 2921 gpm (5,581 total). CCW flow balance data [3.2.6.9, 3.2.6.10, 3.2.6.11, 3.2.6.12, 3.2.6.14, 3.2.6.15, 3.2.6.16], confirms that total CCW flow through the CFC and SDC HX is consistently lower than 5,900gpm).

Therefore, it is conservative to use heat loads derived from using the heat transfer values for 1,350 gpm CFC flowrate and 3,200 gpm SDC HX flowrate (5,900 total).

4.4.8.4.1 WO 247374 - April 2011 - Train B - documents an average of 1,382.1 gpm through the CFCs and 3,096.8 gpm through the SDC HX (5,861 gpm total). [3.2.6.11]

4.4.8.4.2 WO 52368665 - December 2012 - Train A - documents an average of EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 72 OF 119 1,398 gpm through the CFCs and 3,003.5 gpm through the SDC HX (5,799.5 gpm total). [3.2.6.12]

4.4.8.4.3 WO 52363706 - November 2012 - Train B - documents an average of 1,347.5 gpm through the CFCs and 3,034 gpm through the SDC HX (5,729 gpm total). [3.2.6.14]

4.4.8.4.4 WO-52480812 - April 2014 - Train B - documents an average of 1,371 gpm through the CFCs and 3,116 gpm through the SDC HX (5,858 gpm total). [3.2.6.15]

4.4.8.4.5 WO-52476425 - April 2014 - Train A - documents an average of 1,396 gpm through the CFCs and 3,009 gpm through the SDC HX. (5,801 gpm total) [3.2.6.16]

4.4.9 FPC 4.4.9.1 Section 9.1.3.III.1.d of NUREG 800 [3.2.3.2] states, For the maximum normal heat load with normal cooling systems in operation, and assuming a single DFWLYHIDLOXUHWKHWHPSHUDWXUHRIWKHSRROVKRXOGEHNHSW)DQGWKH

liquid level in the pool should be maintained. For the abnormal maximum heat load (full core unload [soon after previous refueling]) the temperature of the pool water should be kept below boiling and the liquid level maintained with normal systems in operation. A single active failure need not be considered for the abnormal case.

4.4.9.1.1 ECM98-067 [3.1.1.45] describes the worst single active failure during a full core offload is the failure that results in only one FPC pump and one CCW pump.

4.4.9.2 The bulk temperature of the spent fuel pool is required to be maintained below 140°F with only one FPC pump and one CCW pump operating.

[3.2.3.2.3]

4.4.9.3 The bulk temperature of the spent fuel pool is desired to be maintained below the alarm setpoint of 135°F +/- 5°F (130°F) under normal conditions when up to two CCW Pumps and two FPC pumps may be operating. Reference B425 Sheet T2000 and Equipment Database Setpoint Parameters for FS ITAC2000-1 [3.1.3.32]

4.4.9.4 Procedure RF-005-001 [3.1.6.20] incorporates commitment A-24899 to the NRC that both FPC pumps will be available prior to commencement of fuel movement during refueling. [3.2.4.14]

4.4.9.5 ECC98-015 [3.1.1.18] qualifies the spent fuel pool for accident temperature up to 212°F. For accidents and abnormal heat loads, the spent fuel pool temperature should be kept below boiling.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 73 OF 119 4.4.10 ACCW Flow Rate 4.4.10.1 MNQ9-50 [3.1.1.56] determines achievable ACCW flow rates to the CCW HX and the Essential Chiller for various lineups.

4.4.10.2 WCT Basin water temperature is related to heat transferred by the Essential Chiller and CCW HX, ambient air wet bulb temperature, and the number of operating WCT fans. When operating from the control room, with the fans control switch in the automatic position, the wet cooling tower fans 1 through 4 and 5 through 8 will start automatically whenever the water temperature in the basin exceeds the setpoint temperature. 81°F turns fans 1 - 4 on. 83.5°F turns fans 5 - 8 on. 79.5°F turns fans 5 - 8 off. 77°F turns fans 1 - 4 off.

Reference B425 Sheets T7077A and T7077B, 5817-660, 5817-661, 5817-690, 5817-698, Equipment Database Setpoint Parameters. [3.1.3.41, 3.1.3.42, 3.1.3.6, 3.1.3.11, 3.1.3.12, 3.1.3.13]

4.4.10.3 MNQ9-50 [3.1.1.56] concludes that ACCW flow capacity is at least 4,500 gpm through the CCW HX shell and at least 850 gpm through the Essential Chiller condenser on each train. Pump minimum recirculation flow is bounded by 200 gpm 4.4.10.3.1PE-004-024 [3.1.6.18] periodically verifies that the ACCW is correctly set up to throttle flow to the CCW HX to balance flow during accident conditions so that 4,500 gpm is delivered to the CCW HX and 850 gpm is delivered to the Essential Chiller. Plant Computer data shows that the normal shutdown ACCW flow to the CCW HX, when the Essential Chiller is in DRY TOWER mode, is 5,200 to 5,300 gpm in agreement with MNQ9-50 [3.1.1.56].

4.4.10.4 Throttling Function of ACC-126A(B) 4.4.10.4.1ACCW Flowrate is controlled by valve ACC-126A(B), which is automatically throttled to control the CCW temperature leaving the CCW HX. The temperature setpoint may be manually input during normal operation and is normally less than 95°F. An SIAS signal raises the setpoint to 117.4°F. Reference B425 Sheets T7075A1, T7075A2, T7075B1, and T7075B2. [3.1.3.37, 3.1.3.38, 3.1.3.39, 3.1.3.40]

4.4.10.4.2ECM96-013 [3.1.1.40] provides the following information:

4.4.10.4.2.1 The jockey pump performance curve is provided as an attachment.

4.4.10.4.2.1.1 75 gpm @ 100 ft TDH 4.4.10.4.2.1.2 100 gpm @ 88 ft TDH 4.4.10.4.2.1.3 112.5 gpm @ 80 ft TDH.

4.4.10.4.2.2 The elevation of the jockey pump is -32.6 ft MSL.

4.4.10.4.2.3 The elevation of the ACCW pump is -32 ft MSL.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 74 OF 119 4.4.10.4.2.4 The jockey pumps will maintain a system high point pressure of approximately 6 psig with a system leakage past ACC-126A(B)]

rate of 80 gpm.

4.4.10.4.2.5 The minimum jockey pump recirculation flow is 23.56 gpm when there is zero leakage past ACC-126A(B).

4.4.10.4.2.6 The jockey pump performance curve shows the header pressure for the minimum recirculation flow rate would be 26.8 psig.

4.4.10.4.2.7 The piping configuration for the jockey pump recirculation line is illustrated on isometric drawings ESSE-CC-231 and ESSE-CC-232.

[3.1.3.43, 3.1.3.44]

4.4.10.4.34305-6258 and 4305-5706 show that the elevation of ACC-126A(B) is

+33ft 2in MSL. [3.1.3.7, 3.1.3.9]

4.4.10.5 ACCW Pump Brake Horsepower 4.4.10.5.15817-9258 [3.1.3.15] and 5817-9259 [3.1.3.16] provide the ACCW pump performance curves, which may be used to correlate pump brake horsepower to flow rate.

Flow, gpm BHP 1250 240 1575 238 2850 253 4650 275 6240 292 4.5 Air Flow Rate 4.5.1 DCT Air Flow 4.5.1.1 Specification 1564.86 [3.1.8.2] specifies that DCT fans are each designed to provide 196,000 cfm of air flow through the DCT bundles at a blade pitch of 13°.

4.5.1.2 Startup testing documented in MNQ9-52 [3.2.1.15] demonstrated that the total DCT fan flow was 2,538,000 scfm for an average DCT fan flow of 169,200 scfm or 181,044 acfm / fan.

4.5.1.3 TD-H291.0025 [3.1.9.6], provides DCT fan performance curves that can be used to determine air flow rate as a function of differential pressure.

4.5.1.4 Engineering Report WF3-ME-15-00014, (LPI A14386-R-001), [3.1.4.5]

investigated the relationship between fan differential pressure and wind speed EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 75 OF 119 and developed a relationship between fan flow rate and wind speed. This relationship along with the relationship between wind speed and ambient dry bulb temperature was used in Engineering Report WF3-ME-15-00013, (LPI A13326-R-003), [3.1.4.4] to develop a relationship between fan flow rate and ambient dry bulb temperature.

4.5.1.5 DCT fans are controlled by CCW HX outlet temperature. Reference B425 Sheets T7075A and T7075B [3.1.3.37, 3.1.3.38, 3.1.3.39, 3.1.3.40]. Fan control is provided by Process Analog Control (PAC) output contact from CC-ITE-7075A-3(B-3), which comes from the CCW HX tube side outlet temperature, per B425 sheet T7075A and T7075B. All fans start in fast mode with CCW HX tube side outlet temperature above 100°F.

4.5.1.6 SFG-36-004 [3.2.6.1] documents tested fan performance.

4.5.1.7 The relationship between the number of fans running and the thermal performance of the DCT is linear. If backflow is allowed through the idle fan, an additional recirculation penalty of 3°F per out-of-service DCT fan is added to the ambient air temperature to bound effect of taking the best performing DCT fan out-of-service. Reference Engineering Reports WF3-ME-15-00014 (A14386-R-001) and WF3-ME-15-00013 (A13326-R-003) [3.1.4.5, 3.1.4.4].

4.5.1.7.1 If out-of-service DCT fans are isolated to prevent back-flow, the penalty may be eliminated.

4.5.2 WCT Air Flow 4.5.2.1 Each WCT consists of two cells, each cell is serviced by 4 induced draft fans, for a total of 8 per WCT. There is a concrete partition between the cells that prevents air recirculation between the fans of each cell. [3.1.9.8]

4.5.2.2 When operating from the control room, with the fans control switch in the automatic position, the wet cooling tower fans 1 through 4 and 5 through 8 will start automatically whenever the water temperature in the basin exceeds the setpoint temperature and stop automatically. [3.1.6.2]

4.5.2.3 Specification 1564.114A [3.1.8.3] specifies that each cooling tower includes eight Aerovent vaneaxial direct drive fan assemblies, Type W, 60 inch diameter with seven adjustable pitch blades. The design fan shaft horsepower is 28.8 hp. The design air flow per fan at design conditions is 58,160 cfm with an air density of 0.0693 lb/cu.ft.

4.5.2.4 SFG-36-004 [3.2.6.1] documents tested fan performance.

4.5.2.5 Periodic GL89-13 WCT performance testing indicates that the WCT fan performance continues to meet original specifications:

4.5.2.5.1 WO-14176 - Train B - 26.8 hp [3.2.6.5]

4.5.2.5.2 WO-12709 - Train A - 25.3 hp [3.2.6.3]

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 76 OF 119 4.5.2.5.3 WO-52348919 - Train B - 27.6 hp [3.2.6.21]

4.5.2.5.4 WO-52372443 - Train A - 25.8 hp [3.2.6.22]

4.5.2.6 The thermal performance of the WCT is empirically determined by curve fitting the Zurn Industries performance curves in TD-Z010.0025 [3.1.9.8].

4.5.2.7 The validity of the performance curves depends on covering out of service fans in order to prevent short cycling of flow from the operating fans.

4.6 Heat Transfer Capacity Inputs 4.6.1 General Thermodynamic Inputs 4.6.1.1 The specific heat of water is 1.0 BTU/lbm*°F. [3.2.2.5]

4.6.1.2 Water properties (specific heat, density, etc.) are determined as a function of temperature based on a curve fit to water properties data from Kreith

[3.2.2.7]. For each component, the average of the inlet and outlet temperatures are used to determine water properties.

4.6.2 DCT Heat Transfer Capacity 4.6.2.1 DCT thermal performance requirements are specified in 1564.86 [3.1.8.2].

4.6.2.2 The performance of the DCT is empirically determined by curve fitting the Hudson Products thermal performance curves in TD-H291.0015 [3.1.9.5].

4.6.2.3 Charts showing manufacturer rated DCT performance are represented mathematically in the Mathcad equations developed in Engineering Report WF3-ME-15-00003 (A13326-R-003) [3.1.4.4]. The equation for the DCT performance also uses fundamental heat transfer principles to determine heat transfer as function of fan flowrate, in addition to water flowrate, ambient temperature and water temperature. Legible copies of the original DCT performance curves are also being placed in TD-H291.0015 [3.1.9.5].

4.6.2.3.1 The performance curves are provided for 100% DCT tube surface area and 95% DCT tube surface area.

4.6.2.3.2 Startup test data, documented in MNQ9-52 [3.2.1.15], demonstrates that the DCT is capable of rejecting 11.95% more heat than the DCT performance curves would predict for a given air inlet temperature, water exit temperature, and water flow rate. The excess capacity is not credited in the design basis, but may be considered as design conservatism. This is considered valid based on the closed cooling water being a closed loop system that has not exhibited fouling problems. This assumption is also supported by the Hudson Product Certified Heat Exchanger Data Sheet, 1564-4983 [3.1.3.6]. The DCT is periodically inspected and cleaned to ensure performance is not degraded. PMIDs 14508, 14509, 5382, and 8549 [3.1.7.1, 3.1.7.2, 3.1.7.3, 3.1.7.4, 3.1.7.5, 3.1.7.7, 3.1.7.8, 3.1.7.14]

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 77 OF 119 define the requirements for inspection and cleaning the tube bundles and performing periodic maintenance on the fans. The DCT is periodically inspected and cleaned to ensure performance is not degraded.

4.6.2.4 Engineering Report WF3-ME-15-00004 [3.1.4.1] evaluates tube sleeving impact as a function of tube plugging impact. For pressure drop, the ratio is 16.5 sleeves to 1 plug. For heat transfer, the ratio is 42.6 sleeves to 1 plug.

4.6.2.5 ECM15-002 [3.1.1.37] demonstrates that pressure drop across the DCT is not impacted by different concentration configurations of tube plugging.

4.6.2.6 DCT fans are controlled by CCW HX outlet temperature. Reference B425 Sheets T7075A and T7075B [3.1.3.37, 3.1.3.38, 3.1.3.39, 3.1.3.40].

4.6.2.7 Recirculation:

4.6.2.7.1 Startup and manufacturer testing documented in MNQ9-52 [3.2.1.15]

showed that the DCT recirculation effect measured 7.78°F.

4.6.2.7.2 Engineering Report WF3-ME-15-00012 (A13326-R-002) [3.1.4.3] and subsequently WF3-ME-15-00014 (A14386-R-001) [3.1.4.5] describes Computational Fluid Dynamics (CFD) modeling that was used to investigate and determine the bounding cooling tower inlet air temperature for a given remote ambient wind speed. The investigation in Engineering Report WF3-ME-15-00011 (A13326-R-001) [3.1.4.2] develops limiting wind - temperature combinations using statistical analysis for the cooling towers under a range of temperature and wind conditions. Engineering Report WF3-ME-16-00001 [3.1.4.8] provides a bounding mathematical relationship between recirculation effect and ambient dry bulb temperature.

4.6.2.7.3 Upon completion of modifications evaluated in EC-52043 [3.2.4.1],

Engineering Report WF3-ME-16-00001 [3.1.4.8] provides the basis for FRQFOXGLQJWKDWWKHERXQGLQJUHFLUFXODWLRQHIIHFW7IRUHYDOXDWLQJFRROLQJ

tower performance (with no fan backflow) for a given ambient temperature is identified in the following table:

Ambient Dry Bulb Bounding Average Critical Time Period Temperature, °F Recirculation Effect, °F 102 0.2 100 2.3 One Hour 98 4.0 96 5.4 93 6.9 90 7.6 One Day 92 0.2 One Day 85 7.0 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 78 OF 119 Ambient Dry Bulb Bounding Average Critical Time Period Temperature, °F Recirculation Effect, °F One Day 80 7.7 Three Day 89 1.3 Three Day 85 5.7 Three Day 80 7.7 Seven Day 86 2.7 Seven Day 80 7.5 Seven Day 75 7.7 4.6.2.7.3.1 The bounding recirculation is conservative for most of the time based on the small fraction of the time when the bounding wind conditions, which are most responsible for producing the recirculation effect, actually occur.

4.6.2.7.4 Engineering Report WF3-ME-15-00014 [3.1.4.5] shows that DCT recirculation is increased by backflow through out-of-service DCT fans.

The increase is bounded by 3°F for one uncovered out-of-service fan, 6°F for two uncovered out-of-service fans, 9°F for three uncovered out-of-service fans.

4.6.2.7.5 The results of the CFD reports are benchmarked against the startup test data in WF3-ME-15-00012 [3.1.4.3] and confirm the validity of the CFD results.

4.6.2.7.6 WF3-ME-15-00014 [3.1.4.5] and WF3-ME-15-00013 [3.1.4.4] also justify and employ a conservative relationship between plant heat load and recirculation effect, which allows crediting a small reduction in recirculation effect as plant heat load drops during an event.

4.6.3 CCW HX Heat Transfer Capacity 4.6.3.1 CCW HX thermal performance requirements are specified in1564.75 [3.1.8.1].

4.6.3.2 Report A13326-R-003 [3.1.4.4] provides an analysis of the CCW HX performance capacity for a wide range of water temperatures and flow rates.

The performance capacity is represented mathematically in the Mathcad equations in UHS model.

4.6.3.3 Details of CCW HX geometry, material specifications, and performance data for developing and validating the heat exchanger model are provided in the following documents:

4.6.3.3.1 457000087 [3.1.9.9]

4.6.3.3.2 5817-10743 [3.1.3.21]

4.6.3.3.3 5817-10744 [3.1.3.22]

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 79 OF 119 4.6.3.3.4 5817-10745 [3.1.3.23]

4.6.3.3.5 5817-10746 [3.1.3.24]

4.6.3.3.6 5817-10747 [3.1.3.25]

4.6.3.3.7 5817-10748 [3.1.3.26]

4.6.3.3.8 5817-10749 [3.1.3.27]

4.6.3.3.9 5817-10750 [3.1.3.28]

4.6.3.3.105817-10751 [3.1.3.29]

4.6.3.4 WOs document testing that supports the predicted performance of the CCW HX by the model with a given fouling factor. The fouling factors determined during testing with 95% confidence are listed below and were used to validate the results of the model:

4.6.3.4.1 WO-14176 [3.2.6.5] Train B - 0.00048 hr*ft2 )%78 4.6.3.4.2 WO-41082 [3.2.6.6] Train B - 0.00151 hr*ft2 )%78 4.6.3.4.3 WO-144200 [3.2.6.7] Train A - 0.00047 hr*ft2 )%78 4.6.3.4.4 WO-186585 [3.2.6.19] Train B - 0.00051 hr*ft2 )%78 4.6.3.4.5 WO-52348919 [3.2.6.21] Train B - 0.00049 hr*ft2 )%78 4.6.3.4.6 WO-52372443 [3.2.6.22] Train A - 0.00016 hr*ft2 )%78 4.6.4 WCT Heat Transfer Capacity 4.6.4.1 WCT thermal performance requirements are specified in 1564.114A [3.1.8.3].

4.6.4.2 The performance curves for the WCT were provided in Operation and Maintenance manual TD-Z010.0025 [3.1.9.8]. However, the curves are illegible and difficult to interpret precise performance data. Legible copies of the curves and digital data were provided using the same methodology by John Cooper and Associates who owns the original cooling tower design and testing records. Engineering Report WF3-ME-16-00011 [3.1.4.9] documents the WCT thermal performance analysis submittals.

4.6.4.2.1 In addition, John Cooper and Associates, who now owns the design of the Waterford 3 WCT, developed thermal performance curves to represent the cooling tower performance with one or more fans isolated and covered and to represent the cooling tower performance with no fans running (natural draft).

4.6.4.3 Report A13326-R-003 [3.1.4.4] represents WCT thermal performance curves mathematically in the Mathcad equations in UHS model.

4.6.4.4 The thermal performance of the WCT is empirically determined by curve fitting the Zurn Industries performance curves in TD-Z010.0025 [3.1.9.6].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 80 OF 119 4.6.4.4.1 WOs document testing that supports the predicted performance of the WCT by the Zurn performance curves. Percent performance with respect to that predicted by the curves with 95% confidence is indicated:

4.6.4.4.1.1 WO-12709 [3.2.6.2] Train A - 107.84%

4.6.4.4.1.2 WO-41082 [3.2.6.6] Train B - 105.54%

4.6.4.4.1.3 WO-144200 [3.2.6.7] Train A - 108.7%

4.6.4.4.1.4 WO-52348919 [3.2.6.21] Train B - 104.7%

4.6.4.4.1.5 WO-52372443 [3.2.6.22] Train A - 108.1%

4.6.4.4.2 MNQ9-53 [3.2.1.16] documents testing that supports the predicted performance of the UHS with the WCT in natural draft mode, which would represent performance after design basis damage from tornado missiles.

4.6.4.4.3 W3I82-0146 [3.2.4.13], identifies the commitment for testing to confirm that predicted performance of UHS components. There is no documented testing to date to demonstrate the accuracy of the performance curves with one or more fans out-of-service and covered. EC-52043 [3.2.4.1],

which implements the new performance curves, requires post return to service testing to validate the new curves.

4.6.4.5 Recirculation:

4.6.4.5.1 Startup and manufacturer testing documented in MNQ9-52 [3.2.1.15]

showed that the WCT recirculation effect was 2.46°F.

4.6.4.5.2 Upon completion of modifications evaluated in EC-52043 [3.2.4.1], WF3-ME-15-00014 (A14386-R-001) [3.1.4.5], provides the basis for concluding that the bounding recLUFXODWLRQHIIHFW7IRUHYDOXDWLQJFRROLQJWRZHU

performance is 6°F wet bulb for any ambient temperature.

4.6.4.5.3 The results of the CFD reports are benchmarked against the GL89-13 test data in WF3-ME-15-00002 and WF3-ME-15-00014 and validate the results of the CFD analysis.

4.6.4.5.4 The bounding recirculation is conservative for most of the time based on the small fraction of the time when the bounding wind conditions, which are most responsible for producing the recirculation effect, actually occur.

4.6.5 FPC HX 4.6.5.1 Engineering Calculation A15503-C-001) [3.1.1.8] develops a heat exchanger performance prediction worksheet for the FPC HX. The results are benchmarked against previous design basis STER results and validate the results of the model.

4.6.5.2 TD-A545.0015 [3.1.9.1] provides the heat exchanger geometry specifications and performance data for the FPC HX that were used to develop the heat EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 81 OF 119 transfer model.

4.6.5.3 WO# 74223 [3.2.6.17] - EOI WF3 Spent Fuel Pool Cooler - Summer 2006 -

Tube Map shows six plugged tubes in the FPC HX.

4.6.5.4 9270-PE-305 [3.1.8.5] shows that the design fouling is 0.0005 ft2-°F-hr/Btu.

4.6.5.5 1564-157 [3.1.3.1] shows an effective tube length of 22 feet for the FPC HX.

4.6.6 Backup (BU) FPC HX 4.6.6.1 Engineering Calculation A15503-C-001) [3.1.1.8] develops a heat exchanger performance prediction worksheet for the BU FPC HX. The results are benchmarked against previous design basis STER results and validate the results of the model.

4.6.6.2 457002178 [3.1.9.11] provides the heat exchanger geometry specifications and performance data for the BUFPC HX that will be used to develop the heat transfer model.

4.6.6.2.1 Passport Work History for FS MHX0002 shows no history of tube plugging in the BUFPC HX.

4.6.7 SDC HX 4.6.7.1 Calculation A15503-C-001 [3.1.1.8] develops a heat exchanger performance prediction worksheet for the SDC HX. The results are benchmarked against previous design basis STER results and validate the results of the model.

4.6.7.2 MNQ9-1 (DRN 05-767) [3.1.1.52] provides shutdown cooling heat exchanger parameters and references to develop a heat exchanger model using STER.

4.6.8 EDG Coolers 4.6.8.1 Calculation A15503-C-001 [3.1.1.8] develops a heat exchanger performance prediction worksheet for the EDG coolers.

4.7 Water Inventory Inputs 4.7.1 Operable WCT Basin Inventory 4.7.1.1 The design basis credited WCT basin inventory is 174,000 gallons based on the following:

4.7.1.1.1 Calculation MNQ9-38 [3.1.1.55] shows that the water storage capacities of the WCT basins are 180,892 gallons on train A and 180,616 gallons on train B between the top of the vortex breaker at elevation -34 ft MSL and the bottom of the overflow pipe at elevation -9 ft MSL.

4.7.1.1.2 The usable volume in the operable trains WCT basin at TS required 97%

level (-9.77 ft MSL) is actually 176,185 gallons in basin A and 175,900 gallons in basin B. [3.1.5.3]

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 82 OF 119 4.7.1.1.3 Factoring instrument uncertainty of 2.19% of span per ECI91-005

[3.1.1.24], an indicated level of 97% is assured to correspond to at least 95.117% actual level, which results in 175,254 gallons in basin A and 174,968 gallons in basin B.

4.7.1.1.4 Note that when indicated level is 0%, there is still at least 23,000 gallons of usable inventory. Inventory below the indicated level is credited in the UHS analyses. [3.1.1.55, 3.1.1.24]

4.7.2 Makeup WCT Basin Inventory 4.7.2.1 The design basis makeup WCT basin inventory is 157,624 gallons for a LOCA and 97,215 gallons for a design basis tornado based on the following:

4.7.2.1.1 Calculation MNQ9-38 [3.1.1.55] shows that the maximum volume that could be transferred from the opposite trains basin via the cross-connect piping is 167,387 gallons for WCT Basin A and 167,303 gallons for WCT Basin B.

4.7.2.1.2 The storage volume available for makeup to the opposite trains basin at 97% (-9.77ft MSL) actual level is 161,767 gallons for basin A and 161,673 gallons for basin B. [3.1.5.3, 3.1.1.55]

4.7.2.1.3 Calculation ECM97-022 [3.1.1.43] evaluates head losses associated with the required flow rates for the design basis tornado and LOCA events and subtracts the level for the respective event to determine the makeup volume that can be credited for each event.

4.7.3 WCT Basin Replenishment 4.7.3.1 Calculation ECM97-022 [3.1.1.43] concludes that the flow capacity of the basin interconnecting piping is at least 50 gpm when the makeup WCT basins level is 0.551 ft above the level in the operable basin. The creditable inventory in the makeup WCT basin is 157,624 gallons to transfer to the operable WCT basin by gravity feed. 50 gpm is greater than the consumption from UHS evaporation and drift several days into a LOCA, when only the chiller loads are on the WCT.

4.7.3.2 RG 1.27 [3.2.3.3] allows evaluation of natural phenomena expected at the site with no two or more such phenomena occurring simultaneously. Therefore, a simultaneous tornado and seismic event is not postulated. This allows for crediting the water that would remain in the underground Circulating Water system piping after a design basis tornado.

4.7.3.3 ECM97-022 [3.1.1.43] concludes that 97,215 gallons of makeup water from makeup WCT basin is available to supply the operable WCT basin by gravity feed in the event of a design basis tornado.

4.7.3.4 ECM97-022 [3.1.1.43] concludes that 688,045 gallons of makeup water from non-seismic Circulating Water intake piping is available to supply the WCT EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 83 OF 119 basins by gravity feed in the event of a design basis tornado.

4.7.3.5 ECM07-002 [3.1.1.36] identifies the design basis requirements for UHS water replenishment to maintain water inventory in the WCT basins following a design basis tornado. The replenishment system is capable of providing an unlimited supply of makeup water and supply a makeup rate of at least 86 gpm. The equipment that makes up the replenishment system would be readily obtainable within the time frame that it would be required following a design basis tornado.

4.7.3.6 The table below shows the limiting water inventory available to the UHS function for each analyzed event based on MNQ9-38 [3.1.1.55] and ECM97-022 [3.1.1.43]. Core offload, normal shutdown, refueling, and normal operations assume normal makeup capability and unlimited water inventory.

Event CSP WCT (credited train) WCT (alt train)

LOCA - LTC Used by EFW 174,000 gal 157,624 gal 1 Non-LOCA Used by EFW 174,000 gal 156,424 gal 2 Tornado Used by EFW 174,000 gal 97,215 gal 3 1

The limiting LTC analysis, CN-OA-08-50 [3.1.1.10], shows that the CSP dedicated inventory plus 6,000 gallons are used for EFW. Other LOCA cases would either use less EFW or would credit two trains of UHS because of a different single active failure. Assumption [5.1.9.3] justifies why the entire second basins inventory can be credited for the LOCA LTC analysis.

2 The natural circulation cooldown analysis, CN-SEE-II-09-21 [3.1.1.14],

shows that the CSP dedicated inventory plus 1,200 gallons are used for EFW. Therefore, the WCT alternate trains credited volume is reduced by 1,200 gallons for the Non-LOCA accident analysis.

3 The design basis tornado event is analyzed to determine when makeup needs to commence in order to maintain the design function. All of the initial water inventory may be used by EFW depending on the extent of the tornado damage and restoration of damaged UHS equipment or the redundant train.

4.7.4 Condensate Storage Pool (CSP) 4.7.4.1 The CSP inventory is not directly usable by the UHS except for makeup to the CCW surge tank. The CSP inventory is used by EFW and the stored volume is used by this calculation for determining the timing for replenishment following a design basis tornado event.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 84 OF 119 4.7.4.1.1 It may be possible to transfer water from the CSP to the WCT basins by using FLEX connections ACC-100A and EFW-1071A/B. However, this is not credited in the design basis.

4.7.4.2 The minimum EFW dedicated water storage capacity of the CSP is 170,000 gallons. [3.1.5.1]

4.7.4.3 TS LCO 3.7.1.3 [3.1.5.1] requires a minimum water level in the CSP of 92%

indicated.

4.7.4.3.1 TS Bases 3/4.7.1.3 [3.1.5.1] states that the CSP with 92% indicated level has a minimum of 173,500 gallons of stored water with 170,000 dedicated to EFW and 3,500 gallons dedicated to CCW Makeup.

4.8 Water Consumption Inputs 4.8.1 LOCA - Long Term Cooling 4.8.1.1 Calculation CN-OA-06-5 [3.1.1.9], along with CN-OA-08-50 [3.1.1.10],

conclude that the bounding EFW consumption for any analyzed case that does not credit two UHS trains is 176,000 gallons. This is 6,000 gallons more than the EFW dedicated portion of the CSP volume.

4.8.1.2 ER-W3-2005-0019-000 [3.2.4.8] identifies that 37,438 gallons are required to refill the steam generators to ensure that the steam generator tubes remain covered.

4.8.1.3 Therefore, 213,438 gallons bounds the EFW consumption for a SBLOCA where steam generators are used for plant cooldown. Assumption [5.1.9.3]

justifies why the entire second basins inventory can be credited for the LOCA LTC analysis.

4.8.2 Natural Circulation Cooldown to 350°F 4.8.2.1 CN-SEE-II-09-21 [3.1.1.14], concludes that under worst case single failure conditions (failed Atmospheric Dump Valve), the amount of EFW needed to reach SDC entry conditions is 229,600 gallons. For the case of a failed EDG, 171,200 gallons of EFW are needed to reach SDC entry conditions.

Assumption [5.2.1.1] justifies why the failed EDG case is more limiting for UHS performance and water inventory margin.

4.8.3 Design Basis Tornado 4.8.3.1 All of the initial water inventory may be consumed by EFW depending on the extent of the tornado damage and restoration of damaged UHS equipment or the redundant train. The shutdown containment heat load inputs [4.3.5.2] are used in determining the design basis tornado EFW consumption.

4.8.4 Water consumption is not a concern for normal operation, normal shutdown, and refueling because normal makeup is available.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 85 OF 119 5.0 Assumptions 5.1 LOCA 5.1.1 A worst case single failure and a LOOP are assumed. When the assumed LOOP occurs, one EDG starts and the other EDG fails to start (single failure).

Conservatively, the failed EDG and its associated safety bus are considered lost for the entire event. This results in only one train of UHS available for heat transfer.

5.1.2 The analysis is based on a combination of the highest reactor core decay heat (End of Cycle) and spent fuel pool decay heat (Beginning of Cycle), which do not occur simultaneously. The core decay heat is approximately 4.5 x 106 BTU/hr lower than the values used in this analysis at the beginning of the cycle, while the spent fuel pool decay heat is approximately 11 x 106 BTU/hr lower than the values used in this analysis at the end of an operating cycle. However, this was not credited in the analysis and so the analysis is conservative for the entire operating cycle by at least 4.5 x 106 BTU/hr. A 25 day refueling outage is assumed for maximum fuel pool heat load. This is a conservative assumption based on historical outage performance.

5.1.3 The CCW supply temperature control valve is assumed to control CCW supply temperature at the low end of the uncertainty band, which is 116.3°F (117.4°F setpoint minus the 1.1°F uncertainty (accounting for decay heat uncertainty

[4.4.4.1.3]) because this maximizes the heat input into the Ultimate Heat Sink and minimizes DCT thermal performance. This calculation will use these maximum heat loads assuming 116.3°F CCW supply temperature to determine the heat removal contributions from the DCT, WCT and the CCW HXs. This is acceptable because if CCW temperature were being controlled at a higher temperature, the containment heat load into the Ultimate heat Sink would be less and the DCT inlet temperature and DCT heat transfer performance would be higher. CCW HX heat duty to supply CCW outlet temperature at 116.3°F maximizes WCT thermal demand and water consumption since the DCT is less effective.

5.1.3.1 The CCW supply temperature control valve is throttled automatically until 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months into the event, when its nitrogen accumulator may be exhausted. After 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months , CCW supply temperature may be controlled manually using the valve handwheel in accordance with established procedures. Essential chiller coolant will automatically be swapped to Wet Tower mode if CCW supply temperature reaches 102°F. The chiller coolant select valves motive gas supply may be recharged locally such that the mission time for remote control of the chiller coolant select valves is 30 days. [3.1.1.47]

5.1.4 In general lower flow rates meeting the minimum requirements of the individual component heat exchangers are preferable because they result in a higher water temperature entering the DCT, which results in better DCT heat transfer and less KHDWWUDQVIHUUHGWRWKH:&7GXHWRWKHJHQHUDOKHDWH[FKDQJHUHTXDWLRQT 8$7

Therefore, the bounding high accident CCW flow rate of 6,900 gpm from MNQ9-2 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 86 OF 119

[3.1.1.53] is used in the analysis to minimize DCT effectiveness and maximize heat transferred to the WCT. [4.4.2]

5.1.5 ECS05-013 [3.1.1.46] calculates Containment Fan Cooler heat removal with no fouling to maximize heat added to the UHS.

5.1.6 The Hot Leg Break (DEHLSB) peak heat load occurs only 18.5 seconds after the event. By 70 seconds after the event, the DEHLSB peak heat load is already lower than the DEDLSB peak heat load, which occurs much later, at which time CCW temperature would have stabilized. Calculation MNQ9-33 [3.1.1.54] shows that the volume of water in the safety related components and piping in one train of the CCW system is more than 9,400 gallons. For that volume of water to change temperature from 95°F to 112°F in 70 seconds would require the average heat input to be more than 10 times the peak heat load determined in ECS05-013 [3.1.1.46]. The area under the heat load vs. time curve illustrates that the total integrated heat load for the DEDLSB is much higher than for the DEHLSB. Therefore, for purposes of determining the peak heat load on the UHS, peak CCW supply temperature, total integrated heat load, and UHS water consumption, it is appropriate to consider the DEDLSB heat load as the design basis containment heat load.

5.1.7 The first part of the LBLOCA UHS strategy is when the peak heat load occurs and is assumed to require only automatic actions:

5.1.7.1 For the LBLOCA, EFW is not considered to be functional as Steam Generator tubes are emptied. Heat from the containment is removed with Safety Injection and Containment Spray.

5.1.7.2 The spent fuel pool is not immediately cooled and its temperature rises until later in the event (approximately 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ) when FPC is manually restored.

5.1.7.3 Therefore, for the first part of the LOCA, the heat loads on the UHS are:

5.1.7.3.1 Heat load from Auxiliaries, SDC HX, and CFC transferred to the CCW system, where a part is dissipated by the DCT and part transferred to ACCW by the CCW HX.

5.1.7.3.2 Heat load from the Essential Chiller transferred directly to the ACCW system.

5.1.7.4 The first part of the Long-Term Cooling event is assumed to last six hours.

5.1.8 The second part of the LOCA - Long-Term Cooling UHS strategy involves manual action to restore FPC within six hours to maintain spent fuel pool temperature less than 180°F:

5.1.8.1 The fuel pool temperature starts at a maximum of 135°F in accordance with OP-002-006 [3.1.6.5].

5.1.8.2 Line up the non-essential CCW loop to restore FPC in accordance with OP-901-510 [3.1.6.9].

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 87 OF 119 5.1.8.3 Throttle CCW to the FPC HX to approximately 850 gpm such that limited cooling is provided to maintain or slowly lower spent fuel pool temperature.

This keeps total heat load below the capacity of the UHS and prevents prematurely exhausting WCT basin inventory and also prevents starving the EDG coolers. [3.1.6.10]

5.1.8.4 The Essential Chiller continues to be cooled by ACCW with the WCT until decay heat reduces to the point where all of the plant heat including the Essential Chiller can be removed with the DCT supplying coolant at less than or equal to 110°F to the components. [3.1.6.1]

5.1.8.5 Therefore, after 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , the heat loads on the UHS are:

5.1.8.5.1 Heat load from FPC, Auxiliaries, SDC HX, and CFC transferred to the CCW system, where a part is dissipated by the DCT and part transferred to ACCW by the CCW HX.

5.1.8.5.2 Heat load from the Essential Chiller transferred directly to the ACCW system.

5.1.8.5.3 ACC-126A(B) throttles ACCW flow through the CCW HX to control CCW supply temperature at 117.4°F. Eventually, decay heat lowers to the point where the DCT alone can maintain CCW supply temperature less than 117.4°F. At this point the CCW HX is secured because ACC-126A(B) closes. When only the Essential Chiller heat load remains on the WCT, then the WCT fans may be secured to reduce water consumption, if necessary. The analysis will confirm that the WCT basin temperature remains less than 110°F with WCT fans secured and only Essential Chiller heat load on the WCT.

5.1.8.5.4 Eventually, decay heat lowers to the point where the DCT alone can maintain CCW supply temperature less than 110°F while dissipating the entire plant heat load. At this point the Essential Chiller coolant select may be taken to DRY TOWER mode and the WCT and ACCW may be secured. [3.1.6.1]

5.1.9 The SBLOCA Long-Term Cooling UHS strategy is the same as for the LBLOCA with the exception that RCS cooling is provided by EFW until SDC can be initiated.

5.1.9.1 The limiting single failures evaluated in the long term cooling analyses are a failed ADV and a failed EDG with a concurrent LOOP. The failed EDG is limiting for UHS water consumption because it results in only one train of UHS. Whereas the failed ADV leaves two trains of DCT, whose capacity would exceed the total plant heat at the start of the event with CCW supply temperature at the SIAS setpoint. [3.1.1.9, 3.1.1.10]

5.1.9.2 Core decay heat is removed with EFW and Safety Injection and containment heat is removed with Containment Spray and CFCs. For the SBLOCA, EFW is considered to be functional as Steam Generator tubes are not emptied. It EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 88 OF 119 would be excessively conservative to consider that core decay heat and containment heat load on the UHS for a SBLOCA is the same as for the LBLOCA. However, there is no SBLOCA containment heat load analysis for the UHS.

5.1.9.3 Input [4.8.1] identifies that the bounding SBLOCA EFW water consumption uses approximately 6,000 gallons + 37,438 gallons from the WCT basin. It is reasonable to assume that the cooling of the containment and RCS with EFW will offset the load on the UHS such that it will result in at least 44,000 gallons less WCT evaporation for a SBLOCA than for a LBLOCA. This is supported by comparing the water consumption of the natural circulation cooldown case where the EFW consumption is similar to the LTC case. UHS water consumption for the Non-LOCA accident cooldown would be bounding because the same total plant heat load (including spent fuel pool cooling) is being cooled while CCW supply temperature is the same. With CCW supply temperature controlled at greater than 116.3°F, the UHS water consumption would be much less because the DCT will be much more effective.

Therefore, the LBLOCA will be considered the bounding LOCA event for UHS water consumption.

5.1.10 The analyses for all cases assume the PASS is secured. The impact is negligible since the operation of the PASS system is intermittent, and the PASS heat load and cooling water flow are negligible. In addition, PASS is required to be placed in service after 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months post-accident, after peak accident heat load has occurred.

[3.2.4.12]

5.1.11 At the 6 hour6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months point in the event, when FPC is required to be lined up, containment heat is significantly reduced from the peak heat load. [3.1.1.46]

5.1.12 The critical time period for evaluating peak heat load and corresponding peak CCW supply temperature is 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months is appropriate based on the heat capacity of the system. [3.1.1.46]

5.1.13 The critical time period for evaluating water consumption is 3 days. 3 days is conservative based on that the water consumption is expected to terminate in approximately 8 days.

5.1.14 The evaporation and drift losses through the WCT for LBLOCA are greater than water losses for the following listed events and thus LBLOCA is the most limiting for the events identified below:

5.1.14.1 Mainsteam Line Break (MSLB) - Blowdown (the period when the break fluid is injected into the containment) of the ruptured steam generator (SG) for MSLB ends a few minutes after the accident. Following blowdown, the RCS decay heat is transferred to the intact SG which, in turn, vents to the atmosphere when its safety relief valves open. Therefore, there is no physical mechanism for the release of significant amounts of mass or energy to the EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 89 OF 119 containment after the end of blowdown for MSLB. Since the energy release into the containment is lower for MSLB, the total heat removal by CCW is lower for MSLB than for LBLOCA and consequently, less water is evaporated through the WCT. Thus LBLOCA is more limiting.

5.1.14.2 Feedwater Line Break (FWLB) - FWLB results in blowdown less limiting than MSLB because the pipe break mass flow for the FWLB is limited by the steam generator internals design. Per calculation CN-SEE-04-28 [3.1.1.12] and CN-SEE-III-08-49 [3.1.1.15] fluid enthalpy for the FWLB is less than the enthalpy of the fluid in the MSLB. As a result, the FWLB has a lower energy release than LBLOCA. Consequently, the heat load on the CCW is smaller for FWLB than for LBLOCA and therefore less water is evaporated through the WCT.

Thus LBLOCA is more limiting.

5.1.14.3 Small Break Loss of Coolant Accident (SBLOCA) - Calculation CN-OA-06-5

[3.1.1.9] along with CN-OA-08-50 [3.1.1.10] conclude that the bounding EFW consumption for any analyzed case that does not credit two UHS trains is 176,000 gallons, which is only slightly more than the volume dedicated for EFW in the CSP. The mass release from the RCS for SBLOCA is less than LBLOCA since the leak flow rate is limited by the size of the break. As a result, for a given RCS pressure and temperature, less energy is released in the SBLOCA than in the LBLOCA. Consequently less water is evaporated through the WCT. Thus LBLOCA is more limiting for WCT evaporation and drift losses. SG cooling with EFW may be available for a SBLOCA.

Therefore, the LBLOCA is more limiting for total water consumption.

5.2 Non-LOCA Accident 5.2.1 A worst case single failure and a LOOP are assumed. When the assumed LOOP occurs, one EDG starts and the other EDG fails to start (single failure).

Conservatively, the failed EDG and its associated safety bus are considered lost for the entire event. This results in only one train of UHS available for heat transfer.

5.2.1.1 The limiting single failures evaluated in the non-LOCA accident analyses are a failed ADV and a failed EDG with a concurrent LOOP. The failed EDG is limiting for UHS water consumption because it results in only one train of UHS. Whereas the failed ADV leaves two trains of DCT, whose capacity would exceed the total plant heat at the initiation of SDC.

5.2.2 The analysis is based on a combination of the highest reactor core decay heat (End of Cycle) and spent fuel pool decay heat (Beginning of Cycle), which do not occur simultaneously. The core decay heat is approximately 4.5 x 106 BTU/hr lower than the values used in this analysis at the beginning of the cycle, while the spent fuel pool decay heat is approximately 11 x 106 BTU/hr lower than the values used in this analysis at the end of an operating cycle. However, this was not credited in the analysis and so the analysis is conservative for the entire operating cycle by at least EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 90 OF 119 4.5 x 106 BTU/hr. A 25 day refueling outage is assumed and the accident is assumed. This is a conservative assumption based on historical outage performance.

5.2.2.1 In addition, the bounding spent fuel pool heat and bounding ambient dry bulb temperatures would not occur at the same time based on scheduling refueling outages for cooler weather conditions. Spring refueling outages are typically scheduled for no later than the beginning of April. Therefore, the analysis uses conservative heat loads and ambient temperature combinations.

5.2.3 The CCW supply temperature setting starts at the normal 90°F. The CCW supply temperature is normally set between 88°F and 92° per OP-002-003 [3.1.6.3].

Temperature control valve, ACC-126A(B), will open as necessary to attempt to maintain 90°F CCW supply temperature. The CCW supply temperature control valve is throttled automatically until 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months into the event, when its nitrogen accumulator may be exhausted. After 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months , CCW supply temperature may be controlled manually using the valve handwheel in accordance with established procedures. The CCW supply temperature setpoint in the analysis is assumed to be 90°F because this maximizes the heat input into the Ultimate Heat Sink and minimizes DCT thermal performance. Since no SIAS signal is initiated, CCW temperature will be maintained at the normal operating setpoint of approximately 90°F. Between the LOOP and the initiation of SDC, the total heat load on the UHS would be only approximately 26 MBTU/hr, which is approximately the capacity of the DCT. [3.1.1.47]

5.2.3.1 Credit is taken for adjusting the CCW supply temperature setting in the control room to ~117°F prior to initiating SDC to maximize DCT performance when the heat load on the UHS is raised. However, CCW supply temperature may rise if the capacity of the UHS is exceeded for maintaining CCW supply temperature at ~117°F. The analysis will determine the CCW supply temperature that can be achieved. The CCW supply temperature control valve is throttled automatically until 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months into the event, when its nitrogen accumulator may be exhausted. After 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months , CCW supply temperature may be controlled manually using the valve handwheel in accordance with established procedures.

5.2.3.2 Credit is also taken for manually isolating CCW to the FPC HX when SDC is initiated until 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months after reactor shutdown. Credit is taken for manually restoring CCW the the FPC HX at approximately 850 gpm for the remainder of the event.

5.2.4 Essential chiller coolant will automatically be swapped to Wet Tower mode if CCW supply temperature reaches 102°F. The chiller coolant select valves motive gas supply may be recharged locally such that the mission time for remote control of the chiller coolant select valves is 30 days. [3.1.1.47]

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 91 OF 119 5.2.5 The cooldown to 200°F consists of two parts:

5.2.5.1 The first part of the cooldown, reactor decay heat is transferred to the steam generators through the ADV with EFW lowering RCS temperature to SDC entry conditions - 350°F. Only auxiliary heat (EDG), normal containment (CFC) heat, FPC heat, and Essential Chiller heat loads are on the UHS.

5.2.5.1.1 The failed EDG case from CN-SEE-II-09-21 [3.1.1.14] shows SDC entry conditions are reached in approximately 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months .

5.2.5.1.1.1 CN-SEE-II-09-21 [3.1.1.14] analyzes two failures, an EDG and an ADV. The ADV failure uses more EFW, but maintains both UHS trains available for heat removal. The capacity of two trains of DCT with DCT exit temperature at 111°F is more than the total heat load on the UHS for this event (considering steaming to SDC entry conditions). With two DCT trains available, WCT heat duty is limited to only the Essential Chiller load. The EDG failure uses less EFW, but results in only one UHS cooling train. Therefore, the EDG failure is bounding for the total water consumption analysis.

5.2.5.1.2 For faster cooldowns, overall water consumption will be less because SDC will be initiated sooner and steam generator cooling will be stopped or at least slowed down sooner.

5.2.5.1.2.1 CN-TAS-03-30 [3.1.1.16] Section 6.2.7.4.5 (Technical Specification RCS Cooldown Rate) discusses cooldown limitations. A maximum RCS cooldown rate increases the steam release during the first two hours and produces more severe 2-Hour EAB Thyroid dose consequences. However, a minimum RCS cooldown allows SG concentrations to build up and produces more severe event duration LPZ Thyroid dose consequences. Four RCS cooldown rates, 40 °F/hr, 50 °F/hr, 75 °F/hr and 100 °F/hr (initiating at 30 minutes, 4 hrs for FWLB, and 45 mins for MSLB OC and IOSGADV) were included in this bounding analysis. The maximum rate allowed is 100 °F/hr. A sensitivity study varying the cooldown rates and the SG level (high and low) was performed to determine the limiting cooldown rate and SG level for maximizing the offsite radiological releases. SDC is assumed to be initiated between 14,000 seconds (3.9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months ) and 27,000 seconds (7.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months ).

5.2.5.1.3 The CFC heat load will be conservatively taken as the heat load calculated in 1-B [3.1.1.1] initially and will be reduced linearly with time to 36% of that value when 350°F is reached in the RCS. This is conservative because the LOOP will have stopped the RCP's and other electrical loads.

1-B shows that the mechanical, piping, and CFC motor loads make approximately 60% of the normal heat load. After SDC entry conditions are reached, the temperature of the RCS piping will be approximately 58%

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 92 OF 119 of the normal operating temperature. In addition, any heat taken out of containment by the CFC would not have to be taken by EFW to maintain decay heat removal. Including the normal CFC loads would be double dipping the containment heat loads. Therefore, it is still conservative to use only 36% of the CFC heat load after shutdown cooling entry conditions are reached.

5.2.5.2 The second part of the cooldown is via SDC with decay heat and sensible heat of the RCS added to the UHS.

5.2.5.2.1 SDC is initiated when SDC entry conditions are reached. A limiting worst case cooldown rate limit will be determined by this analysis such that CCW supply temperature can be maintained less than 120°F under bounding ambient conditions with minumum TS fan requirements. For a fast cooldown to SDC entry conditions, the limit for the post SDC cooldown rate may be as low as 6°F/hr. Faster cooldown rates would be achievable as more time elapses since the shutdown. Therefore, the heat loads determined in CN-SEE-II-08-6 [3.1.1.13], which are based on 40°F/hr initial cooldown rate after SDC entry, will not be used in this analysis.

5.2.5.2.2 CN-SEE-II-09-21 [3.1.1.14] demonstrates that natural circulation temperature difference across the steam generator is approximately 30°F at the time of SDC entry conditions at 8 - 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months after shutdown. RCS heat is approximately 100 MBTU/hr at 8 - 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months after shutdown. Based on fundamental thermodynamics, the natural circulation flow rate is approximately 7,500 gpm. In addition, several other natural circulation analyses show that the natural circulation flow rates are approximately 600 - 700 lbm/s (5,000 gpm) per steam generator. Therefore, it is reasonable to conclude that natural circulation at up to 4,000 gpm would be achievable in at least one steam generator after commencement of shutdown cooling. This is based on 4,000 gpm SDC flow and 4,000 gpm steam generator tube flow with no additional losses to overcome above the analyzed natural circulation flow rate. Therefore, steam generator heat removal could supplement SDC heat removal, if necessary. This would allow initiating SDC as soon as possible while limiting heat on the UHS such that CCW temperature could be maintained below 120F.

NUREG 0800 BTP 5-4 describes this method of heat removal and malfunction procedure OP-901-131 provides implementing instructions.

5.2.5.3 The critical time period for evaluating the Non-LOCA accident is 3 day. 3 day is conservative based on that the time to reach cold shutdown conditions is expected to be approximately 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months and the water consumption analysis shows that the mission time of the WCT for the worst case shutdown event is on the order of 3 days. A study case is included for worst case 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months ambient conditions for peak heat load and TS minimum fan configuration.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 93 OF 119 5.3 Design Basis Tornado 5.3.1 The Design Basis Tornado damages 40% of the DCT tube bundles and all eight WCT fans. Therefore, after the tornado, the UHS capacity is reduced to only 60% of the DCT and the WCT in natural draft operation.

5.3.1.1 The DCT tube bundles outside of the tornado missile shielding and their associated fans, as well as all of the WCT fans are assumed to be damaged.

5.3.2 A worst case single failure and a LOOP are assumed. When the assumed LOOP occurs, one EDG starts and the other EDG fails to start (single failure).

Conservatively, the failed EDG and its associated safety bus are considered lost for the entire event. This results in only one train of UHS available for heat transfer.

5.3.3 Conservatively, the failed EDG and safety bus are associated with the intact UHS train and only the damaged UHS train is available for heat removal.

5.3.4 The analysis is based on a combination of the highest reactor core decay heat (End of Cycle) and spent fuel pool decay heat (Beginning of Cycle), which do not occur simultaneously. The core decay heat is approximately 4.5 x 106 BTU/hr lower than the values used in this analysis at the beginning of the cycle, while the spent fuel pool decay heat is approximately 11 x 106 BTU/hr lower than the values used in this analysis at the end of an operating cycle. However, this was not credited in the analysis and so the analysis is conservative for the entire operating cycle by at least 4.5 x 106 BTU/hr. A 25 day refueling outage is assumed and the accident is assumed. This is a conservative assumption based on historical outage performance.

5.3.5 The design basis tornado coping strategy consists of four parts:

5.3.5.1 Part 1 - (0 - 2hrs) consists of both automatic and manual operator actions:

5.3.5.1.1 When the assumed LOOP occurs, the reactor is shut down and decay heat is removed with EFW. EFW is supplied from the CSP and steam is exhausted to the atmosphere by the ADV.

5.3.5.1.1.1 The calculation assumes that reactor vessel core decay heat is initially removed with EFW and continues to be removed with EFW until SDC entry conditions are reached and plant heat is lower than the capacity of the damaged UHS. EFW consumption will be calculated based on a bounding decay heat curve developed in accordance with NUREG 0800, BTP ASB9-2 [3.2.3.2.2].

5.3.5.1.1.2 Conservatively assume that all RCS heat is removed by EFW until the RCS is cooled to 350°F. This is conservative because it does not credit any heat removal by the CFC, however, the CFC heat is also considered later in the UHS loads.

5.3.5.1.1.3 The CFC heat load will be conservatively taken as the heat load EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 94 OF 119 calculated in 1-B [3.1.1.1] initially and will be reduced linearly with time to 36% of that value when 350°F is reached in the RCS. This is conservative because the LOOP will have stopped the RCP's and other electrical loads. 1-B shows that the mechanical, piping, and CFC motor loads make approximately 60% of the normal heat load. After SDC entry conditions are reached, the temperature of the RCS piping will be approximately 58% of the normal operating temperature. In addition, any heat taken out of containment by the CFC would not have to be taken by EFW to maintain decay heat removal. Including the normal CFC loads would be double dipping the containment heat loads. Therefore, it is still conservative to use only 36% of the CFC heat load after shutdown cooling entry conditions are reached.

5.3.5.1.1.4 The sensible heat removal to reduce RCS temperature to SDC entry conditions could conservatively take place over time that it takes to reduce RCS temperature to SDC entry conditions at the maximum cooldown rate specified in OP-902-003 [3.1.6.13], but SDC would not be initiated until the damaged DCT can dissipate the decay heat while supplying CCW to the components at less than 120°F per OP-009-005 [3.1.6.7].

5.3.5.1.1.5 Final enthalpy of the steam from the ADV is based on conservative minimum 212°F @ 0 psig. This is very conservative because the enthalpy based on minimum SDC steaming conditions of 350°F and 134.6 psia would be 1193 BTU/lbm. The actual enthalpy change will therefore be much greater than this for most of the cooldown.

5.3.5.1.2 The tornado damage causes leaks through the DCT tube bundles, which in turn lowers the CCW Surge Tank level.

5.3.5.1.3 The lowering CCW Surge Tank level causes the DCT to be bypassed, the CCW trains to be split, and the non-essential CCW loop to be isolated on lowering CCW surge tank level. CCW bypasses the isolated DCT and is cooled only by the CCW HX while the damaged DCT coils are isolated and the undamaged parts are being restored to service later in the event.

5.3.5.1.4 The calculation assumes that FPC is isolated after the tornado on lowering CCW surge tank level, which splits the trains and isolates non-essential cooling loops. Therefore, the spent fuel pool temperature will rise during the time that FPC is isolated after the event.

5.3.5.1.5 The CCW HX is cooled by the WCT in Natural Draft mode. The WCT operates in natural draft mode where ACCW water is sprayed over the fill as normal but without forced draft from the fans.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 95 OF 119 5.3.5.1.5.1 The CCW supply temperature setting starts at the normal 90°F.

5.3.5.1.5.2 Temperature control valve, ACC-126A(B), will open as necessary to attempt to maintain 90°F CCW supply temperature.

5.3.5.1.5.3 Credit is taken for sensible heating of the WCT basin during the first two hours after the tornado. The WCT heat transfer capacity from evaporation is very low in Natural Draft mode with basin temperature at 89°F and return temperature around 95°F.

Therefore, the basin water temperature and CCW temperature will rise.

5.3.5.1.5.4 WCT Evaporation for first 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months is estimated by conservatively considering the natural draft heat transfer for the entire two hours.

The method of determining the evaporation rate also conservatively does not credit much of the sensible heating.

5.3.5.1.5.5 The Essential Chiller conservatively transfers to WET TOWER mode within 30 minutes based on when CCW HX exit temperature reaches 102°F.

5.3.5.1.5.6 The Essential Chiller heat is transferred directly by ACCW.

Auxiliary loads and CFC heat are transferred to ACCW by the CCW HX.

5.3.5.1.6 Within two hours, operators take manual action to:

5.3.5.1.6.1 Isolate the damaged DCT tube bundles using manual handwheels on the isolation valves for the damaged DCT tube bundles per OP-901-521 [3.1.6.11].

5.3.5.1.6.2 The DCT tube bundle isolation valves are maintained and periodically verified to leak less than 8 gpm total. [3.1.7.5, 3.1.7.8, 3.1.7.9, 3.1.7.10, 3.1.7.11, 3.1.7.12] 8 gpm total leakage past all eight of the DCT tube bundle isolation valves required to isolate damaged tubes is assumed for the entire event. The analysis accounts for potential 10 gpm total system leakage for the tornado event.

5.3.5.1.6.3 After isolating the damaged DCT Tube bundles, restore the undamaged DCT tube bundles to service per OP-901-521

[3.1.6.11].

5.3.5.1.6.4 After restoring the undamaged parts of the DCT to service, adjust the CCW supply temperature to 120°F either remotely or by manually throttling ACC-126A(B). This action assumes that the WCT fans are not functional and prevents raising the WCT basin water temperature above Essential Chiller limitations per OP-901-521 [3.1.6.11].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 96 OF 119 5.3.5.2 Part 2 - (2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months - 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ) consists of both automatic and manual operator actions:

5.3.5.2.1 For this part and the remainder of the event, the DCT is restored to service at 60% capacity. This reduces load on the CCW HX and WCT, which will be controlled by throttling ACC-126A(B) to limit heat removed by the CCW HX. This may be done by adjusting the CCW temperature setpoint to 120°F in the control room or by manual handwheel control in accordance with established procedures. [3.1.6.1]

5.3.5.2.2 FPC is assumed to be restored by 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months after the tornado. Therefore, the spent fuel pool temperature will rise during the 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months that FPC is isolated after the event. The calculation determines the sensible heat that needs to be removed to restore normal fuel pool temperature and adds that heat to the UHS over 30 days to slowly restore fuel pool temperature.

[3.1.6.10]

5.3.5.2.3 The Essential Chiller continues to be cooled by ACCW with the WCT on natural draft.

5.3.5.2.4 Auxiliary loads and CFC heat continue to be transferred to by the DCT.

5.3.5.2.5 The second part of the tornado coping strategy is assumed to last six hours.

5.3.5.3 Part 3 - (6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months - SDC conditions) consists of both automatic and manual operator actions:

5.3.5.3.1 The third part of the tornado event requires manual operator action to implement WCT Basin replenishment in accordance with ECM07-002

[3.1.1.36] such that enough water is available to maintain EFW operation until the sum of core decay heat, spent fuel pool heat, CFC heat, and auxiliary heat is less than the capacity of damaged UHS. SDC may be initiated before that time but supplemental cooling with steam generators may be required. ECM07-002 [3.1.1.36] describes the portable equipment required. Procedure EP-002-100 [3.1.6.1] provides adequate guidance for setting up for WCT basin replenishment system.

5.3.5.3.2 For this part and the remainder of the event, FPC is restored and adds its heat load onto the CCW system.

5.3.5.3.2.1 The non-essential FPC loop is manually lined up to restore FPC before the pool heats up to 180°F in accordance with OP-901-513

[3.1.6.10].

5.3.5.3.2.2 The CCW to the FPC HX is throttled to approximately 825 gpm such that limited cooling is provided to maintain or slowly lower spent fuel pool temperature. This keeps total heat load below the capacity of the damaged DCT tube bundles and prevents EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 97 OF 119 overheating CCW supply temperature. This is also consistent with the flowrate supported by MNQ9-2 [3.1.1.53].

5.3.5.4 Part 4 - (SDC entry to End) consists of both automatic and manual operator actions:

5.3.5.4.1 The fourth part of the tornado coping strategy requires manual operator action to determine when SDC can be initiated and EFW can be secured.

5.3.5.4.1.1 SDC can be initiated when the sum of core decay heat, spent fuel pool heat, CFC heat, and auxiliary heat is less than the capacity of damaged UHS. Alternatively, SDC can be initiated with SDC entry conditions are reached in accordance with OP-009-005 [3.1.6.7]

while continuing to remove some heat with the steam generators with EFW and ADV manipulations. The latter method reduces water consumption.

5.3.5.4.1.2 CN-SEE-II-09-21 [3.1.1.14] demonstrates that natural circulation temperature difference across the steam generator is approximately 30°F at the time of SDC entry conditions at 8 - 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months after shutdown. RCS heat is approximately 100 MBTU/hr at 8 - 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months after shutdown. Based on fundamental thermodynamics, the natural circulation flow rate is approximately 7,500 gpm. In addition, several other natural circulation analyses show that the natural circulation flow rates are approximately 600 -

700 lbm/s (5,000 gpm) per steam generator. Therefore, it is reasonable to conclude that natural circulation at up to 4,000 gpm would be achievable in at least one steam generator after commencement of shutdown cooling. This is based on 4,000 gpm SDC flow and 4,000 gpm steam generator tube flow with no additional losses to overcome above the analyzed natural circulation flow rate. Therefore, steam generator heat removal can supplement SDC heat removal until RCS heat load is less than 55 MBTU/hr. This would allow initiating SDC as soon as possible while limiting heat on the UHS such that CCW temperature could be maintained below 120F.

5.3.5.4.1.3 The capacity of the damaged UHS will depend on ambient conditions. This analysis will use bounding ambient conditions.

5.3.5.4.1.4 The SDC HX heat load will be assumed to be the damaged UHS capacity at bounding ambient conditions for the critical time period of seven days associated with the design basis tornado event.

5.3.5.5 The critical time period for evaluating the design basis tornado event is 7 days. 7 days is conservative based on that the water consumption is expected to last more than 30 days.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 98 OF 119 5.4 Full Core Offload and Normal Refueling 5.4.1 For the full core offload analysis, all DCT and WCT fans are assumed to be available to account for seasonal high ambient temperature, unless justified by a cycle specific evaluation.

5.4.2 Since TS 3.8.1.2 [3.1.5.5] allows one electrical bus to be out of service during modes 5 and 6, a failure of the remaining bus would not allow for any safety functions to be performed and is therefore beyond design or license basis. However, for conservatism and meeting the intent of the SRP design requirement, the analysis for the normal refueling full core offload will assume the worst case single active failure that results in only one train of UHS, one CCW pump, and one FPC pump operating.

See ECM98-067 [3.1.1.45] for additional details and assumptions.

5.4.3 Both FPC pumps will be available prior to commencement of fuel movement during refueling. This allows for the analyzed single failure that results in only one operational FPC pump, which is used in the analysis. [3.1.6.20]

5.4.4 It is assumed that refueling schedules will comply with the core offload time of year restrictions in section [2.1.4.3.2] and the core offload hold time restrictions in

[2.1.4.3.1] unless justified by a cycle specific evaluation. [3.1.6.20]

5.4.4.1 Bounding seasonal meteorological conditions are also established for refueling outages, which are typically between October and April. [3.1.1.45]

5.4.5 For the abnormal case, (full core offload with 150 hour0.00174 days 0.0417 hours 2.480159e-4 weeks 5.7075e-5 months hold time with 36 days decay of previous batch), both FPC pumps are operational and two UHS trains are operational because NUREG 0800 section 9.1.3 [3.2.3.2.3] does not require consideration of a single active failure for the abnormal maximum heat load. For simplicity and conservatism the CCW flow rate through the FPC HXs for the single failure case will be used, but the FPC flow rate will be for both FPC pumps in parallel. The CCW supply temperature will be conservatively assumed to be 90°F since both UHS trains are operational. PMC data shows CCW HX outlet WHPSHUDWXUHLVFRQVLVWHQWO\)HYHQRQWKHKRWWHVWGD\VDQGZLWKWKHKLJKHVW

shutdown heat loads with two trains of UHS in service.

5.4.6 Containment Fan Coolers are assumed to be isolated from CCW. OP-002-003 section 8.1 [3.1.6.3] requires switching Containment Fan Coolers from CCW to Temporary Chilled Water upon reaching Mode 5 conditions.

5.4.7 HPSI and CS pumps are not required for a core offload. LPSI pump is required for core shuffle only but is included for all cases for conservatism.

5.4.8 If only one train of UHS, one CCW pump, and one FPC pump is available during full core offload with the reactor subcritical less than 15 days, then the non-functional train may need to be isolated such that all of the CCW flow will be through the cooling towers with the functional fans and the CCW HX with the functional ACCW pump in the event of a LOOP, where EDG cooling is needed. This is accomplished EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 99 OF 119 by splitting the CCW trains, using guidance in OP-901-510 [3.1.6.9], as applicable.

In addition, CC-963A(B) must be placed in the setpoint position to ensure adequate CCW flow through the FPC HX, per OP-009-005 [3.1.6.7] (mode 6). The FPC CCW Temperature Control Valve, CC-620, will be required to be manually reset and opened after the trains are split.

5.4.9 The critical time period for evaluating the full core offload is 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months is appropriate based evaluating peak temperature in the spent fuel pool and on the heat capacity of the system.

5.5 Normal Operation 5.5.1 Two UHS trains are operating with essential and non-essential cooling loops lined up. [3.1.5.3, 3.1.6.2, 3.1.6.3]

5.5.2 The Boric Acid Concentrators are only used for performance testing WCT and CCW HX performance testing; therefore, it is assumed that the heat load from these components on the CCW system are considered only for normal operation and refueling cases.

5.5.3 The CCW supply temperature controls much more precisely and efficiently when using the ACCW system to supplement cooling. Lower CCW supply temperature is required to keep DCT fans from starting in automatic. Therefore, a CCW supply temperature below 90°F during normal operations, normal shutdown, and refueling is desirable. OP-002-003 [3.1.6.2] says to maintain CCW temperature below 105°F.

SD-CC [3.1.10.1] says to CCW temperature is controlled between 88°F and 92°F during normal operations.

5.5.4 The critical time period for evaluating normal operation is 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months is appropriate based evaluating peak temperature in the UHS and on the heat capacity of the system.

5.6 Normal Shutdown 5.6.1 Two UHS trains are operating with essential and non-essential cooling loops lined up.

5.6.2 It is assumed that the heat load transferred to the CCW system from the CFCs during a shutdown will be bounded by the CFC heat load during normal operation determined in Calculation 1-B [3.1.1.1]. 1-B did not specifically address the containment fan cooler heat loads during normal shutdown or refueling. The basis for the assumption is that heat load from the mechanical equipment, motors, system leakage, shield wall, cables and piping will decrease during shutdown because of the lower primary system temperature, lower primary system flow rate and lower electrical power requirements inside containment. The heat load from lighting during shutdown will be approximately the same as the lighting heat load during normal operation.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 100 OF 119 5.6.3 The critical time period for evaluating normal shutdown is 3 day. 3 day is appropriate based on that the time to reach cold shutdown conditions is on the order of greater than 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months and the water consumption analysis shows that the mission time for the WCT for the worst case shutdown event is on the order of 8 days.

5.7 General Heat Transfer Assumptions 5.7.1 Heat transfer from CCW and ACCW piping is not credited. This is very conservative because heat load from CCW piping contributes significantly to the Essential Chiller heat load. The Essential Chillers attempt to maintain design basis room temperatures in the Reactor Auxiliary Building. The room temperatures are lower than the uninsulated CCW piping, which runs through them. Therefore, as per calculations 5-T [3.1.1.6] and its references, significant heat is transferred from the warm CCW piping and external surfaces of component heat exchangers to the room coolers. That heat transfer is conservatively accounted for only as gross heat load to the Essential Chillers in determining the capacity of the UHS but could be realistically treated as removed from the total UHS heat load by the piping.

5.7.2 Passive transfer of heat from the spent fuel pool to the fuel handling building HVAC system is not included in the analysis. This conservatism adds at least 80,000 BTU/hr to the FPC system and UHS. [3.1.1.45]

5.7.3 DCT 5.7.3.1 This analysis credits new Dry Cooling Tower Recirculation Barriers (DCTRB) installed by EC-52043 [3.2.4.1] as an improvement to reduce recirculation.

5.7.3.2 The DCT is assumed to operate with less than 80 (2.4%) plugged tubes.

The effect of tube plugging on thermal performance of the DCT is evaluated in accordance with the original Hudson Products DCT performance curves in TD-H291.0015 [3.1.9.5] assuming a linear interpolation between 0% and 5%

tube plugging. The linear relationship assumption is appropriate because the heat transfer capacity of a heat exchanger is directly proportional to the surface area of the tubes.

5.7.3.3 Tube sleeving is limited by flow performance impact and thermal performance impact.

5.7.3.3.1 Flow impact is evaluated based on MNQ9-2 [3.1.1.53], which assumes 5%

DCT tube plugging which is equivalent to 2772 sleeved tubes based on a ratio of 16.5 sleeved tubes to 1 plugged tube per WF3-ME-15-00004

[3.1.4.1].

5.7.3.3.2 Thermal performance impact is based on the maximum possible 100%

tube sleeving and a ratio of 42.6 sleeved tubes to 1 plugged tube per WF3-ME-15-00004 [3.1.4.1].

5.7.3.4 DCT Tube Sleeve and Plug combinations are listed in the table below based on the relationships described in [4.6.2] and [5.7.3.3] to have an equivalent EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 101 OF 119 impact on heat transfer of 2.4% tube plugging (80) or an equivalent impact on flow resistance of 5% tube plugging (168). Values in between may be determined by linear interpolation. The more limiting (lower) value must be used for allowed tube sleeves.

Tube Plugs Allowed Tube Allowed Tube Installed Sleeving Based on Sleeving Based on Flow Resistance Thermal S = 16.5 (168 - P) S = 42.6 (80 - P) 80 1452 0 60 1782 852 40 2112 1704 20 2442 2513 0 2772 3360 (100%)

5.7.3.5 CFD investigations identified that an out-of-service DCT fan allows back flow through the idle DCT, which raises the total recirculation effect by 3°F/out-of-service fan. This phenomenon can be prevented by covering the exhaust side of the tube bundles adjacent to the out-of-service fan. If the backflow is prevented, then no additional recirculation effect is applicable. [3.1.4.5]

5.7.3.6 The analysis assumes that all 10 DCT tube bundles are in service (6 for Tornado event). This includes times when three fans on the same cell are considered out-of-service based on fan restrictions. In the event that it is desired to isolate a DCT tube bundle during normal operation, separate more restrictive fan requirements based on ambient temperature conditions would be required.

5.7.3.6.1 For the tornado event, 60% DCT tube bundles under the missile shield are EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 102 OF 119 assumed to be in service. All DCT fans associated with the protected DCT tube bundles are assumed to be in service.

5.7.4 WCT 5.7.4.1 This analysis requires additional one time testing to validate the new WCT performance curves with isolated fans. The testing is specified as part of EC-52043 [3.2.4.1] implementation.

5.7.4.2 Preoperational testing of the WCT in natural draft mode was performed and documented in study calculation MNQ9-53 [3.2.1.16]. The data from that test was used to calibrate new performance curves for the WCT in natural draft mode. [3.1.4.9]

5.7.4.3 Periodic testing of the WCT with all 8 fans operable is performed to validate the thermal performance curves provided by Zurn Industries and John Cooper and Associates in TD-Z010.0025 [3.1.9.8] and used in the UHS analysis model [3.1.4.4] for all 8 WCT fans operating.

5.7.4.4 Out-of-service WCT fans must be isolated by covering the exhaust stack in order to consider the associated cell of the WCT operable. Out-of-service WCT fans would allow short circuiting of air from adjacent fans in the same cell. Short circuiting of fan flow significantly reduces the tower performance by reducing air flow through the tower fill.

5.7.4.4.1 Each WCT consists of two cells. Each cell is serviced by 4 induced draft fans, for a total of 8 per WCT. There is a concrete partition between the cells that prevents air recirculation between the fans of each cell.

5.7.4.5 The analyses in this calculation assume that ACCW water flows over the fill in both WCT cells even if all four fans on the same cell are considered out-of-service. In the event that it is desired to isolate ACCW water from one WCT cell during normal operation, a separate evaluation of the impact on heat transfer performance and more restrictive fan requirements and limits for ambient temperature would be required.

5.7.4.6 Air exiting the wet cooling towers is assumed to be saturated in accordance with standard cooling tower evaluation methods. [3.2.2.5]

5.7.4.7 WCT drift losses are assumed to be 0.1% of design ACCW flow rate. This is conservative because startup testing documented in MNQ9-52 [3.2.1.15]

demonstrated drift loss was actually 0.026%.

5.7.4.8 Natural draft WCT thermal performance following a design basis tornado would not be significantly affected by a WCT fan cover. This is based on information in engineering report WF3-ME-16-00011 [3.1.4.9] and conversations with the manufacturers lead engineer. Therefore, air flow and overall thermal performance are expected to be close to the same in natural draft mode with a WCT fan covered. In addition, the analysis is based on the EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 103 OF 119 assumption that none of the WCT fans function after the tornado, which is very unlikely and reasonably bounding for evaluating the design basis. Also, operating procedures include precautions for loading the WCT and maintaining basin temperature during a tornado event after the first two hours.

Therefore, the only impact is how much ACC-126A(B) is opened and potentially the cooldown rate for shutdown cooling. The evaporation rate would not be impacted. In conclusion, the cooling water temperatures would not exceed the limits considering the margins determined for the eight opening configuration and the impact on water consumption would be negligible. Therefore, additional analysis cases are not required.

5.7.5 CCW HX 5.7.5.1 The CCW HX performance is periodically tested in accordance with GL89-13

[3.2.3.4] to verify that the Fouling Factor is less than or equal to the allowable fouling factor. Performance trends show significant margin currently exists.

The most recent test in 2014 [3.2.6.21, 3.2.6.22] shows actual fouling including uncertainty less than 0.0005 hr ft2 °F / BTU. There are currently no plugged CCW HX tubes.

5.7.5.2 The CCW HX is assumed to operate as predicted by the Mathcad worksheet shown in Attachment 8.13 [3.1.4.4] that models the performance of the performance of the CCW HX with no more than 5% plugged tubes and a fouling factor no more than 0.0012 hr ft2 °F / BTU. The CCW HX is periodically tested in accordance with PE-004-021 [3.1.6.17]. The Mathcad worksheet contains validation cases based on actual testing to verify that the worksheet accurately predicts CCW HX performance. The difference between the fouling and tube plugging assumed in the analysis and the actual fouling and tube plugging is margin.

5.7.6 FPC HX 5.7.6.1 The Standards of Tubular Exchanger Manufacturers Association (TEMA) normal fouling factor of 0.0005 hr-ft2-°F/BTU for treated water <125°F is conservatively high for each side of the tubes and may be used as conservative fouling for the CCW HX and FPC HXs. The following justifies that this value is very conservative when high standards for water purity and corrosion prevention are employed.

5.7.6.1.1 9270-PE-305 [3.1.8.5] specifies a 0.0005 hr-ft2-°F/BTU fouling factor both inside and outside of the tubes for design.

5.7.6.1.2 Fuel Pool water and CCW chemistry are well maintained. The FPC HX tubes are stainless steel. Therefore, the mechanisms for fouling are minimized.

5.7.6.1.3 The TEMA recommended design fouling factor of 0.0005 hr-ft2-°F/BTU for treated water <125°F was used in the design specification 9270-PE-305 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 104 OF 119

[3.1.8.5]. TEMA published a table of fouling factors to assist the designer in preventing the fouling of a single item in a process, including several items of heat transfer equipment. Resistances were tabulated which were to be added to the film resistances of specific process streams so that the operating period of each would be similar and assure some desired period of continuous operation. The tables of fouling factors were intended as a crude guide toward the equalization of cumulative fouling in all fouling streams in the assembly. The fouling factors published by TEMA became entrenched in industrial heat exchanger design. Fouling factors, by the TEMA definition, are time dependent. They are not present when the apparatus is placed on stream. When a heat exchanger is in service for a certain amount of time under certain process conditions, scale and dirt will deposit on the surface of the tubes. These deposits reduce the rate of heat transfer between the fluids by increasing the resistance to heat flow through the tube wall. Reference [3.2.2.8] and [3.2.2.12].

5.7.6.1.4 For a typical heat exchanger it would be necessary to double the size of the unit if a fouling factor of 0.0001 hr-ft2-°F/BTU was used on each side of the plate (i.e. a total fouling of 0.0002 hr-ft2-°F/BTU). Although fouling is of great importance, there is relatively little accurate data available, and the rather conservative figures [TEMA] are used all too frequently. It also may be said that many of the high fouling resistances quoted have been obtained from poorly operated plants. If a clean exchanger, for example, is started and run at the designed inlet water conditions, the heat transfer capacity would be much higher than the design capacity.

5.8 General Water Inventory Assumptions 5.8.1 Condensate Storage Pool 5.8.1.1 Emergency Operating Procedure, OP-902-006 [3.1.6.14] along with OP-902-009 [3.1.6.16] direct makeup to the CSP from the WCT Basins when CSP level is less than 25%. However, at this condition, the inventory in the CSP is still available for plant cooldown. Therefore, the makeup to the CSP has no impact on the total available inventory for the plant cooldown.

5.8.1.2 It may be possible to transfer water from the CSP to the WCT basins by using FLEX connections ACC-100A and EFW-1071A/B. However, this is not credited in the design basis.

5.8.2 Wet Cooling Tower Basins 5.8.2.1 The water inventory from both WCT basins will be available. This assumption is valid because either the safety-related cross-connection piping or the basin itself would have to fail to prevent the inventory from being available. Based on the single failure criterion, the passive failure does not need to be considered on top of an active failure that resulted in only one train of UHS EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 105 OF 119 being available.

5.8.2.2 The instrument uncertainty associated with WCT basin level may be eliminated if level is measured locally rather than with remote instrument indication. The volume of water associated with the instrument uncertainty could be used to compensate for degraded conditions such as valve closure or system leakage problems.

5.9 EDG Heat Load Assumptions 5.9.1 PMC data was used to show that EDG heat load on CCW varies proportionally with EDG MW output.

5.9.1.1 The following charts were developed using Plant Monitoring Computer data to show the proportional relationship between EDG electrical load and cooling water heat load. The following data points were used:

5.9.1.1.1.1.1 A60101, EDG A LOAD 5.9.1.1.1.1.2 A45603, CCW HX A OUTL TEMP 1 5.9.1.1.1.1.3 A60404, EDG A HX CCW OUTL TEMP 5.9.1.1.1.1.4 S60402, EDG A HX CCW OUTL FLOW 5.9.1.1.1.1.5 A60201, EDG B LOAD 5.9.1.1.1.1.6 A45703, CCW HX B OUTL TEMP 1 5.9.1.1.1.1.7 A60412, EDG B HX CCW OUTL TEMP 5.9.1.1.1.1.8 S60410, EDG B HX CCW OUTL FLOW EDG A Heat Load vs Output Load 100%

90%

80%

70%

% Rated Output - % Rated Heat Load 60%

50%

%load - EDGA 40%

%heat - EDGA 30%

20%

10%

0%

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 106 OF 119 EDG B Heat Load vs Output Load 100%

90%

80%

70%

60%

% Rated Output - % Rated Heat Load 50%

40% %load - EDGB

%heat - EDGB 30%

20%

10%

0%

5.10 Other assumptions are explained in the body of the calculations and attachments.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 107 OF 119 6.0 Method of Analysis 6.1 LOCA 6.1.1 Heat loads from containment are treated as transient for the LOCA event. The heat loads from ECS05-013 [3.1.1.46] are used. ECS05-013 produces heat load profiles for the two bounding LOCA events, DEDLSB and DEHLSB. Three heat load profiles are provided for each break type based on CCW supply temperatures of 112°F, 115°F, and 120°F.

6.1.2 Heat loads from the spent fuel pool are also treated as a transient for the LOCA event. The non-refueling heat loads from ECM98-067 [3.1.1.45] are used. The bounding fuel pool heat loads are based on a 25 day refueling outage based on section [4.3.4].

6.1.3 A Mathcad worksheet, LOCA Loads.xmcdz [8.13.5], which captures the LOCA heat loads from ECS05-013 [3.1.1.46], bounding spent fuel pool heat loads from ECM98-067 [3.1.1.45], and shutdown cooling heat loads on the UHS, is described in Engineering Report WF3-ME-15-00013, (LPI A13326-R-003) [3.1.4.4] and is used in this calculation for the containment and fuel pool heat loads for the LOCA event.

6.1.4 A Mathcad worksheet, UHS1.xmcdz [8.13.1], references LOCA Loads.xmcdz and determines the containment heat load on the UHS during the transient event, based on CCW supply temperature selection or limitation. The methods of analysis for the UHS1.xmcdz worksheet and its reference worksheets are documented in Engineering Report WF3-ME-15-00013, (LPI A13326-R-003) [3.1.4.4].

6.1.5 UHS1.xmcdz evaluates heat transfer performance, water temperatures, and water consumption for the LOCA event. UHS1.xmcdz also references DCT.xmcdz

[8.13.2], WCT.xmcdz [8.13.4], CCWHX.xmcdz [8.13.3], Recirc.xmcdz [8.13.6], and Water Properties.xmcdz [8.13.7] worksheets, which were developed in Engineering Report WF3-ME-15-00013 (LPI A13326-R-003) [3.1.4.4] to model the heat transfer performance of the UHS. The following describe the user inputs for the LOCA analyses:

6.1.5.1 LOCA Cold Leg (RCP Discharge) Break (DEDLSB) is selected for the Type of Analysis. As discussed in section [5.1.6], the sensible heat capacity of the volume of water in the CCW system is credited for transferring the peak heat load for at least 70 seconds where the very short spike in heat load occurs for a DEHLSB. This justifies using the DEDLSB heat load (LOCA Cold Leg (RCP) Break) as the bounding containment peak heat load and bounding containment integrated heat load for the analysis.

6.1.5.2 Heat loads from reactor auxiliaries and Essential Chiller are treated as constant based on the inputs in sections [4.3.2] and [4.3.3].

6.1.5.3 The Essential Chiller cooling will be supplied by the ACCW loop based on

[5.1.7.3.2] and [5.1.8.4].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 108 OF 119 6.1.5.4 A switch in the UHS1.xmcdz worksheet can be used to select whether fuel pool heat loads are considered or not. For this bounding calculation, bounding FPC heat loads are considered.

6.1.5.5 CCW flow rate is based on section [4.4.1].

6.1.5.6 The CCW control temperature is based on [4.4.4.1].

6.1.5.7 ACCW flow rate is based on [0]. UHS1.xmcdz calculates the ACCW flow rate required to achieve the CCW supply temperature selected. The ACCW flow rate supplied by the user is treated as an upper limit, which accounts for potential pump degradation.

6.1.5.8 Essential Chiller Flow is based on [4.4.6].

6.1.5.9 CCW HX tube plugging and fouling assumptions are based on [5.7.5].

6.1.5.10 The Recirc.xmcdz worksheet controls meteorological parameters based on the relationships with dry bulb temperature, critical time period, and number of DCT fans in service defined in [4.2], including bounding coincident wet bulb temperature, bounding coincident wind speed, limiting DCT fan flow, and bounding coincident recirculation, when the following identities are used in UHS1.xmcdz:

6.1.5.10.1Twb := Twb 6.1.5.10.2DCTR := DCTR 6.1.5.10.3AIR := AIR 6.1.5.10.4DCTOOS := DCTOOS_noc 6.1.5.10.5The recirculation penalty for out-of-service DCT fans can be eliminated by making DCTOOS := 0 based on [4.5.1.7].

6.1.5.11 The limit variable is set to 110 to define the Essential Chiller coolant temperature limit. This variable is used to establish the projected time when the analysis should stop the water consumption based on switching the Essential Chiller back to Dry Tower mode.

6.1.5.12 The MAR variable is set to at least 250 to define the minimum flow through the CCW HX, which is the difference between total ACCW flow rate and Essential Chiller flow rate in gpm where the transient evaluation will stop.

Stopping the evaluation is required to prevent the CCW HX model from returning imaginary results, which causes no answer in the UHS1 worksheet.

A study is included that demonstrates high values for MAR, which are necessary for some cases, produce slighty conservative results .

6.1.6 UHS1.xmcdz is run for various ambient dry bulb temperatures and fan combinations, while the relationships in the Recirc.xmcdz worksheet control the other meteorological parameters, including bounding coincident wet bulb temperature, EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 109 OF 119 bounding coincident wind speed, limiting DCT fan flow, and bounding coincident recirculation.

6.1.6.1 Peak CCW supply temperature is determined using a critical time period of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months based on [5.1.12].

6.1.6.2 Water consumption is determined using a critical time period of 3 days based on [5.1.13].

6.1.6.3 Water consumption cases with various WCT fans out-of-service are studied to demonstrate that water consumption is bounding when all eight WCT fans are in service. Therefore, water consumption cases are performed with all eight WCT fans.

6.1.7 The peak CCW temperature results and water consumption results of UHS1.xmcdz are combined into SET1 and SET2, respectively. SET2 is not applicable to the runs using the 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months critical time period.

6.1.8 SET1 and SET2 results for the various cases are pasted into a Microsoft Excel spreadsheet to facilitate reporting and comparing the results.

6.1.9 out0, out1, and out2 produce output files TIME, TEMP, and WCT_loss, respectfully, which may be stored for each case for producing graphical illustrations or point in time results.

6.1.10 The spreadsheet calculates the margin with respect to the limiting CCW supply temperature of 120°F [4.4, 8.7.1] and the available water inventory of 331,624 gallons [4.7.3].

6.1.11 Additional cases are performed with UHS1.xmcdz with all 15 DCT fans (and 14 DCT fans), 8 WCT fans, and 90% DCT area available to simulate isolating one DCT tube bundle for maintenance. Critical time periods of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and 3 days are used to determine the ambient temperature restrictions and margins when isolating a DCT tube bundle for maintenance.

6.2 Non-LOCA Accident 6.2.1 The first part of the Non-LOCA accident is evaluated in CN-SEE-II-09-21 [3.1.1.14],

which determines the bounding amount of water inventory consumed to reach SDC entry conditions.

6.2.1.1 CN-SEE-II-09-21 [3.1.1.14] determines the water consumption based on a relatively slow cooldown rate, which maximizes the time to reach SDC entry conditions and therefore maximizes water consumption by the steam generators to remove RCS heat. Entering SDC sooner would reduce water consumption.

6.2.2 The second part of the Non-LOCA accident (after SDC is initiated) is evaluated similar to the LOCA with the following exceptions:

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 110 OF 119 6.2.2.1 Heat loads from containment are treated as transient for the Non-LOCA accident. A Mathcad worksheet, Non-LOCA_accident.xmcd [8.2.1] was developed to calculate the shutdown cooling containment heat load profile using inputs from section [4.3.5.2] to establish a reasonable time for commencing shutdown cooling. The worksheet also benchmarks the time to reach shutdown cooling conditions with the results of CN-SEE-II-09-21

[3.1.1.14] and CN-SEE-II-08-6 [3.1.1.13] to confirm the validity of the worksheet inputs and method.

6.2.2.2 The Non-LOCA_Accident.xmcd worksheet references another Mathcad worksheet, Decay_Heat_ASB92_2s.xmcd, [8.2.4], which provides a decay heat profile based on the methodology provided in NUREG-0800 Branch Technical Position (BTP) ASB 9-2 [3.2.3.2.2]. The methodology is benchmarked against ANSI /ANS 5.1-1994 decay heat fractions documented in calculation CN-WFE-03-9 [3.1.1.17].

6.2.2.3 The Non-LOCA_Accident.xmcd worksheet also references another Mathcad worksheet, SDC.xmcdz [8.2.4], which models the SDC Heat Exchanger, in order to demonstrate that the achievable flow rates and inlet temperatures to the SDC HX will support the evaluated cooldown rates.

6.2.2.4 The results from the worksheet are captured in a shutdown table in the LOCA loads worksheet described in [6.1.3] above.

6.2.2.5 The UHS1.xmcdz worksheet described in [6.1.4 and 6.1.5] is used similar to the LOCA with the following exceptions:

6.2.2.6 Non-LOCA Shutdown is selected for the Type of Analysis.

6.2.2.7 The CCW control temperature is based on [4.4.4Error! Reference source not found.].

6.2.2.8 The critical time periods for the analysis are 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and 3 day based on

[5.2.5.3].

6.2.3 SET1 and SET2 results for the various cases are pasted into a Microsoft Excel spreadsheet to facilitate reporting and comparing the results.

6.2.4 out0, out1, and out2 produce output files TIME, TEMP, and WCT_loss, respectfully, which are stored for each case for producing graphical illustrations or point in time results.

6.2.5 Water inventory margin is calculated with respect to the analyzed CCW supply temperature of 120°F [4.4] and the available water inventory of 330,424 gallons

[4.7.3].

6.2.5.1 The total water UHS water consumption is determined by adding the basin water consumed by both parts. The available water inventory factors in the consumption during the first part by EFW.

EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 111 OF 119 6.3 Tornado 6.3.1 Heat loads from containment and the spent fuel pool are treated as transient for the Tornado event. A Mathcad worksheet Tornado_UHS.xmcd [8.3] was developed to calculate the EFW consumption, the time for commencing shutdown cooling as well as the heat loads and WCT evaporation throughout the event.

6.3.2 Tornado_UHS.xmcd references Decay_Heat_ASB92_2s.xmcd described in

[6.2.2.2].

6.3.3 The tornado coping strategy [5.3.5] is modeled in the Tornado_UHS.xmcd [8.3]

worksheet to produce a complete transient analysis to determine bounding heat loads, water temperatures, and water consumption for the event.

6.3.4 Tornado_UHS.xmcd references DCT.xmcdz [8.13.2], WCT.xmcdz [8.13.4],

CCWHX.xmcdz [8.13.3], Recirc.xmcdz [8.13.6], and Water Properties.xmcdz

[8.13.7] worksheets, which were developed in Engineering Report WF3-ME 00013 (LPI A13326-R-003) [3.1.4.4] to model the heat transfer performance of the UHS.

6.3.5 Inputs from section [4.3.5.2] are used to calculate sensible heat from cooling the RCS as a transient based on selected cooldown rate and time.

6.3.6 The Tornado_UHS.xmcd benchmarks the sensible heat results and the decay heat results with the results of CN-SEE-II-08-6 [3.1.1.13] to confirm the validity of the worksheet inputs and method.

6.3.7 Tornado_UHS.xmcd calculates the EFW flow rate and total consumption as a function of time after the event based on the change in enthalpy between the CSP and the ADV. The enthalpy at the ADV is conservatively considered to be based on 212°F @ 0 psig. EFW pump heat is also considered. The mass rate of consumption is determined by dividing the RCS heat load by the change in enthalpy of the EFW.

6.3.8 Timing for certain event milestones used in the analysis are estimated and verified (trial and error) to establish valid times for the event milestones, such as the time when SDC can be initiated and EFW can be secured while maintaining CCW supply temperature less than or equal to 120°F.

6.3.9 Heat loads from reactor auxiliaries and Essential Chiller are treated as constant based on the inputs and assumptions in sections [4.3.2] and [4.3.3].

6.3.10 Heat loads are expressed as functions of time after the tornado and added together to establish the total heat on the UHS as a function of time after the tornado.

6.3.11 UHS parameters are defined based on the inputs and assumptions to support use of the DCT.xmcdz, CCWHX.xmcdz, WCT.xmcdz, and Recirc.xmcdz worksheets to evaluate UHS performance.

6.3.12 The critical time period is 7 days based on [5.3.5.5].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 112 OF 119 6.3.13 Additional recirculation from out-of-service fans is not applied based on that any out-of-service fans would not be in cells associated with the credited tube bundles.

Therefore, recirculation flow would be significantly restricted. Finally, the heat load on the DCT is relatively low with respect to the LOCA heat loads that were used to establish the recirculation effects.

6.3.14 CCW flow rates are based on [4.4.1].

6.3.15 ACCW flow rates are based on [0].

6.3.16 Essential Chiller flow rates are based on [4.4.6].

6.3.17 The predicted range of the WCT for various ACCW flow rates and wet bulb temperatures with limiting WCT basin temperature are based on WCT natural draft performance curves in Engineering Report WF3-ME-16-00011.

6.3.18 CCW supply temperatures settings are established based on the heat load at various times during the event. The CCW supply temperature must be relatively high in order for the degraded DCT capacity to match the heat loads.

6.3.19 The UHS heat load is plotted along with the DCT capacity based on CCW flow rate and supply temperature.

6.3.20 The difference between DCT capacity and UHS heat load is the load on the WCT.

The WCT load is reviewed to ensure that the basin temperature limit (Essential Chiller coolant temperature limit) is not exceeded.

6.3.21 For the first two hours of the tornado event, while the DCT is bypassed to line up undamaged DCT tube bundles and all of the heat load is being transferred to the WCT, credit is taken for the heat capacity of the water in the WCT basin to demonstrate that WCT Basin water temperature will not exceed the required Essential Chiller coolant temperature.

6.3.22 The WCT evaporation is determined based on the transient WCT heat load.

6.3.23 The total water consumption is determined by adding the EFW consumption, WCT evaporation, and leakage.

6.3.24 The consumption is compared to the various inventory volumes to determine times when replenishment sources need to be aligned.

6.3.25 The methods are described in detail within the Tornado_UHS calculation worksheet in [8.3].

6.4 Full Core Offload 6.4.1 Heat loads from the spent fuel pool are calculated in ECM98-067 [3.1.1.45] for various core offload conditions.

6.4.2 ECM98-067 [3.1.1.45] also uses the heat transfer capacity of the FPC HXs to determine the required CCW supply temperature to transfer the heat at the limiting CCW flow rate to the FPC HX.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 113 OF 119 6.4.3 The Full Core Offload is evaluated similar to the LOCA with the following exceptions:

6.4.3.1 Operating Loads is selected for the Type of Analysis.

6.4.3.2 Heat loads from the reactor auxiliaries and Essential Chiller are treated as constant based on the inputs and assumptions in sections [4.3.2] and [4.3.3].

6.4.3.3 The Essential Chiller cooling will be supplied by the CCW loop based on

[4.4.6.1] and that CCW temperature will be well below 102°F.

6.4.3.4 The FPC switch does not affect the results for the Operating Loads analysis type. The constant FPC loads are entered from ECM98-067 [3.1.1.45].

6.4.3.5 CCW flow rate is based on section [4.4.1].

6.4.3.6 The CCW control temperature is based on ECM98-067 [3.1.1.45].

6.4.3.7 ACCW flow rate is conservatively 5,100 gpm based on [0]. UHS1.xmcdz calculates the ACCW flow rate required to achieve the CCW supply temperature selected. The ACCW flow rate supplied by the user is treated as upper limit.

6.4.3.8 Essential Chiller Flow is based on [4.4.6].

6.4.3.9 CCW HX tube plugging and fouling assumptions are based on [5.7.5].

6.4.3.10 The Recirc.xmcdz worksheet controls meteorological parameters based on the relationships with dry bulb temperature and number of DCT fans in service defined in [4.2], including bounding coincident wet bulb temperature, bounding coincident wind speed, limiting DCT fan flow, and bounding coincident recirculation, when the following identities are used in UHS1.xmcdz:

6.4.3.10.1Twb := Twb 6.4.3.10.2DCTR := DCTR 6.4.3.10.3AIR := AIR 6.4.3.10.4DCTOOS := DCTOOS_noc 6.4.3.11 The Operating Loads analysis type does not evaluate water consumption and so there is no need to supply the limit or MAR values.

6.4.4 UHS1.xmcdz [8.13.1] is run for various ambient dry bulb temperatures and FPC heat load combinations, while the relationships in the Recirc.xmcdz worksheet control the other meteorological parameters, including bounding coincident wet bulb temperature, bounding coincident wind speed, limiting DCT fan flow, and bounding coincident recirculation. The objective is to demonstrate that ambient temperatures expected between October and April can support the capability of the UHS to supply the limiting CCW supply temperature while removing the FPC heat load for the design basis core offload hold time.

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 114 OF 119 6.5 Normal Operation, Shutdown, and Refueling 6.5.1 Heat loads are based on [4.3].

6.5.2 The Normal Operation, Normal Shutdown, and Normal Refueling UHS capacities are evaluated similar to the LOCA with the following exceptions:

6.5.2.1 Operating Loads is selected for the Type of Analysis.

6.5.2.2 Heat loads from the reactor auxiliaries and Essential Chiller are treated as constant based on the inputs and assumptions in sections [4.3.2] and [4.3.3].

6.5.2.3 The Essential Chiller cooling will be supplied by the CCW loop based on

[4.4.6.1] and that CCW temperature will be well below 102°F.

6.5.2.4 The FPC switch does not affect the results for the Operating Loads analysis type. The constant FPC loads are entered from ECM98-067 [3.1.1.45].

6.5.2.5 CCW flow rate is based on section [4.4.1].

6.5.2.6 The CCW control temperature is based on [5.5.3].

6.5.2.7 ACCW flow rate is conservatively 5,100 gpm based on [0]. UHS1.xmcdz calculates the ACCW flow rate required to achieve the CCW supply temperature selected. The ACCW flow rate supplied by the user is treated as upper limit.

6.5.2.8 Essential Chiller Flow is based on [4.4.6].

6.5.2.9 CCW HX tube plugging and fouling assumptions are based on [5.7.5].

6.5.2.10 The Recirc.xmcdz worksheet controls meteorological parameters based on the relationships with dry bulb temperature and number of DCT fans in service defined in [4.2], including bounding coincident wet bulb temperature, bounding coincident wind speed, limiting DCT fan flow, and bounding coincident recirculation, when the following identities are used in UHS1.xmcdz:

6.5.2.10.1Twb := Twb 6.5.2.10.2DCTR := DCTR 6.5.2.10.3AIR := AIR 6.5.2.10.4DCTOOS := DCTOOS_noc 6.5.2.11 The Operating Loads analysis type does not evaluate water consumption and so there is no need to supply the limit or MAR values.

6.5.3 The number of UHS trains is set to 2 for normal operation.

6.6 EDG Heat Removal Capability with 120°F CCW Supply Temperature 6.6.1 The methods are described in Attachment [8.7.1].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 115 OF 119 6.7 ACC-126A(B) CCW Temperature Control Valve Closing Acceptance Criteria 6.7.1 ACC-126A(B) opens and throttles to control the flow rate of ACCW through the CCW HX as required to maintain CCW supply header temperature at the setpoint. The setpoint is normally selected by the operator to be approximately 95°F. The setpoint is automatically raised to 117.4°F upon receipt of a SIAS. Maintaining the CCW supply temperature less than 120°F is important because cooling water to the components is required to be less than or equal to 120°F. Maintaining CCW supply temperature high is also important because lower CCW temperature reduces the heat transfer capacity of the DCT and results in more water consumption by the WCT. The water consumption analysis assumes that the bounding low SIAS CCW temperature is 116.3°F. [4.4.4.1.3]

6.7.2 The ACCW jockey pump is designed to maintain at least 5 psig at the high point of the ACCW system. If the pressure falls below 5 psig, then the main ACCW pump will start to prevent a void from forming in the ACCW system that could cause a water hammer. [3.1.1.40]

6.7.3 The ability of the ACCW jockey pump to maintain header pressure is evaluated in ECM96-013 [3.1.1.40], which shows that that 80 gpm leakage past ACC-126A(B) results in ACCW high point pressure of approximately 6 psig.

6.7.4 The flow rate through a partially open ACC-126A(B), during an accident, while the main ACCW pump drives the flow, can be related to the flow rate past ACC-126A(B), with the same opening, while the jockey pump drives the flow, based on the Bernoulli conservation of energy equation and the Darcy head loss equation.

6.7.5 The methods are described in detail in Attachment [8.9].

6.8 ACCW Pump 7 Day Average Brake Horsepower 6.8.1 ACCW flow through the CCW HX is proportional to CCW HX heat duty, which is determined from the LOCA analysis [8.10].

6.8.2 The brake horsepower (BHP) of the ACCW pump during a LOCA is proportional to the ACCW flow based on the ACCW pump performance curves. [3.1.3.15, 3.1.3.16]

6.8.3 The transient ACCW flow determined from the UHS Model run for the LOCA event will be used to calculate the transient BHP for the ACCW Pump.

6.8.4 The methods are described in detail in Attachment [8.10].

6.9 CCW HX and WCT Performance Test Evaluation 6.9.1 The methods used for evaluating the thermal performance testing of the CCW HX and WCT are described in Attachment [8.11].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 116 OF 119 7.0 Calculations 7.1 LOCA 7.1.1 The calculations for LOCA are in Attachment [8.1].

7.2 Non-LOCA Accident 7.2.1 The calculations for the non-LOCA accident are in Attachment [8.2].

7.3 Tornado 7.3.1 The calculations for tornado are in Attachment [8.3].

7.4 Full Core Offload 7.4.1 The calculations for full core offload are in Attachment [8.4].

7.5 Normal Shutdown 7.5.1 The calculations for normal shutdown are in Attachment [8.5].

7.6 Normal Refueling 7.6.1 The calculations for normal refueling are in Attachment [8.6].

7.7 Normal Operation 7.7.1 The calculations for normal operation are in Attachment [8.7].

7.8 Acceptability of 120°F CCW Supply Temperature 7.8.1 The calculations to show acceptability of 120°F CCW supply temperature to the EDG are in Attachment [8.8].

7.9 ACC-126A(B) Closure Requirements 7.9.1 The calculations to determine the acceptance criteria for measuring the capability of ACC-126A(B) to close are in Attachment [8.9].

7.10 7 Day Average Brake Horsepower for ACCW Pumps During LOCA 7.10.1 The calculations to determine the 7 day average brake horsepower of the ACCW pumps during LOCA are in Attachment [8.10].

7.11 CCW HX and WCT Thermal Performance Test Evaluation Template 7.11.1 The calculations to determine the thermal performance capacity margin of the WCT and CCW HX are in Attachment [8.11].

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 117 OF 119 8.0 Attachments 8.1 UHS Analysis - LOCA 8.1.1 Bounding Analysis - LOCA Peak Heat Load - UHS1_LOCA_Peak.xmcdz (9 pages) 8.1.2 Bounding Analysis - LOCA Water Consumption - UHS1_LOCA_Water.xmcdz (17 pages) 8.1.3 CCW Temperature Margin vs Dry Bulb Temperature for Various Fan Combinations -

LOCA_Margin_PHL.xlsm (2 pages) 8.1.4 UHS Model Results - LOCA PEAK HEAT LOAD - LOCA_Margin_PHL.xlsm (122 pages) 8.1.5 UHS Water Inventory Margin vs Dry Bulb Temperature for Various Fan Combinations - LOCA_Margin_LTC.xlsm (1 page) 8.1.6 UHS Model Results - LOCA Water Consumption - LOCA_Margin_LTC.xlsm (50 pages) 8.1.7 One DCT Tube Bundle Isolated for Maintenance - UHS1.xmcdz (26 pages) 8.1.8 CCW Temperature Setpoint and Uncertainty Evaluation (3 pages) 8.1.9 Ambient for 15 DCT Fans and No ACCW System (1 page) 8.2 UHS Analysis - Non-LOCA Accident Analysis 8.2.1 Non-LOCA Accident Heat Loads and Cooldown Worksheet - Non-LOCA_accident.xmcd (12 pages) 8.2.2 Heat Transfer Capacity and Water Consumption Summary for Non-LOCA Accident (2 pages) 8.2.3 Non-LOCA Accident Analysis 8.2.3.1 13 DCT fans with DCTFBP 8.2.3.1.1 Fast Cooldown - Bounding UHS Heat Load - 1 hr - UHS1.xmcd (9 pages) 8.2.3.1.2 Fast Cooldown - Bounding UHS Heat Load - 3 day - UHS1.xmcd (17 pages) 8.2.3.1.3 Fast Cooldown - without FPC - UHS1.xmcd - 3 day - (17 pages) 8.2.3.2 All DCT Fans 8.2.3.2.1 Fast Cooldown - Bounding UHS Heat Load - 3 day - all fans -

UHS1.xmcd (17 pages) 8.2.3.2.2 Fast Cooldown - without FPC - UHS1.xmcd - 3 day - all fans - (17 pages) 8.2.4 SDC HX Worksheet - SDC.mxcdz (8 pages)

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Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 118 OF 119 8.2.5 Decay Heat Worksheet - Decay_Heat_ASB92_2s.xmcd (3 pages) 8.3 UHS Analysis - Design Basis Tornado 8.3.1 Coping Strategy Worksheet - Tornado_new_UHSv4.xmcd (36 pages) 8.3.2 Ambient for 8 DCT Fans Under Missile Shield - findDCTcapacity.xmcd (1 page) 8.4 UHS Analysis - Full Core Offload - UHS1_FCO.xmcdz (9 pages) 8.5 UHS Analysis - Normal Shutdown - UHS1_NS.xmcdz (9 pages) 8.6 UHS Analysis - Normal Refueling (Core Shuffle) - UHS1_RF.xmcdz (9 pages) 8.7 UHS Analysis - Normal Operation 8.7.1 Without Concentrator Heat Load - UHS1_NO.xmcdz (9 pages) 8.7.2 With Concentrator Heat Load - UHS1_NOwConc.xmcdz (9 pages) 8.8 EDG Heat Removal Capability with 120°F CCW Temperature 8.8.1 EDG Heat Removal Evaluation - 120F_Evaluation.xmcd (13 pages) 8.8.2 EDG JW HX Worksheet - EDGJW.xmcdz (8 pages) 8.8.3 EDG LO HX Worksheet - EDGLO.xmcdz (10 pages) 8.9 ACC-126 A(B) Closure Requirements - ACC-126_Close.xmcd (7 pages) 8.10 ACCW Pump Brake Horsepower During LOCA - ACCW_Pump_BHP.xmcd (3 pages) 8.11 Thermal Performance Evaluation Worksheet Templates 8.11.1 CCW Heat Exchanger Performance Evaluation Template - CCW_HX_Test.xmcd (19 pages) 8.11.2 WCT Performance Evaluation Template - WCT_Test.xmcd (16 pages) 8.12 License Basis Document Figures 8.12.1 FSAR Figure 9.2 Heat Load Dissipation of UHS After LOCA (1 page) 8.12.2 FSAR Figure 9.2-4a - WCT Integrated Heat Load After LOCA - Essential Loads (1 page) 8.12.3 FSAR Figure 9.2 Heat Removal Capacity of Dry Cooling Tower vs. Dry Bulb Temperature (1 page) 8.12.4 Figure 9.2-5a - Bounding Meteorological Conditions for UHS to Dissipate Design Basis Heat Load (1 page) 8.12.5 TS Table 3.7 Ultimate Heat Sink Minimum Fan Requirements Per Train (1 EN-DC-126 R006

Waterford 3 Calculation ECM95-008 REV. 3 Ultimate Heat Sink Design Basis PAGE 119 OF 119 page) 8.13 UHS Model Worksheets 8.13.1 UHS1 Worksheet - UHS1.xmcdz (17 pages) 8.13.2 DCT Worksheet - DCT.xmcdz (9 pages) 8.13.3 CCW HX Worksheet - CCWHX.xmcdz (6 pages) 8.13.4 WCT Worksheet - WCT.xmcdz (14 pages) 8.13.5 LOCA Loads Worksheet - LOCA Loads.xmcdz (4 pages) 8.13.6 Recirc Worksheet - Recirc.xmcdz (4 pages) 8.13.7 Water Properties Worksheet - Water Properties.xmcdz (2 pages)

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v t e Letter Sequence Supplement
EPID:L-2018-LLA-0080, Response to U. S. Nuclear Regulatory Commission Request for Additional Information Regarding Proposed Change to Technical Specification 3/4.7.4 for Ultimate Heat Sink Design Basis Update (Approved, Closed)
Initiation Request Acceptance, Acceptance Supplement Administration Questions 28 January 2019 Answers Results Approval Other: ML18171A040
MONTHYEAR2018-06-07 [Table View]

W3F1-2018-0025, (Waterford 3) - Supplemental Information Supporting the License Amendment Request Regarding Proposed Change to Technical Specification 3/4.7.4 for Ultimate Heat Sink Design Basis Update

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