Text

Request for a License Amendment to Technical Specification 3.7.9, Ultimate Heat Sink
	ML14231A902
Person / Time
Site:	Braidwood
Issue date:	08/19/2014
From:	Gullott D; Exelon Generation Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	RS-14-193
	Download: ML14231A902 (175)
	v • d • e

RS-14-193 August 19, 2014 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 10 CFR 50.90

Subject:

Request for a License Amendment to Braidwood Station, Units 1 and 2, Technical Specification 3.7.9, "Ultimate Heat Sink"

Reference:

Letter from Daniel J. Enright (EGC) to U.S. Nuclear Regulatory Commission, "Request for Enforcement Discretion for Technical Specification 3.7.9 'Ultimate Heat Sink,"' dated July 10, 2012 In accordance with 1 O CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Exelon Generation Company, LLC (EGC), is submitting a request for amendment to Facility Operating License Nos. NPF-72 and NPF-77 for Braidwood Station, Units 1 and 2. Currently, Technical Specification (TS) Surveillance Requirement (SR) 3.7.9.2 states: "Verify average water temperature of UHS is s; 100°F." If the Ultimate Heat Sink (UHS) temperature is> 100°F, Technical Specification (TS) 3.7.9 Required Actions A.1 and A.2 would be entered concurrently, requiring both Braidwood Station Units 1 and 2 to be placed in Mode 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and Mode 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

Recent meteorological conditions have resulted in the TS UHS temperature being challenged.

These conditions include elevated air temperatures, high humidity, and low wind speed.

Specifically, July 4 through July 6, 2012 brought unprecedented hot weather and drought conditions to the northern Illinois area resulting in sustained elevated UHS temperatures. On July 7, 2012, the Braidwood Station average discharge temperature of the running essential service water pumps, used to monitor compliance with TS SR 3.7.9.2, exceeded 100°F. As a result, Braidwood Station verbally requested and received Enforcement Discretion to avoid an unnecessary plant shutdown and associated transient as a result of compliance with TS 3.7.9, Condition A. Although the Request for Enforcement Discretion (Reference) indicated that a License Amendment Request was not necessary at the time since the conditions requiring the requested Enforcement Discretion were atypical, in order to address future meteorological conditions that may continue to challenge the current UHS TS temperature limit of :5100°F, this License Amendment Request (LAR) is being sought to increase the TS SR 3.7.9.2 allowable temperature to :5102°F.

August 19, 2014 U.S. Nuclear Regulatory Commission Page 2 As described in Regulatory Guide (RG) 1.27 Revision 2, "Ultimate Heat Sink for Nuclear Power Plants," the predicted response of the UHS temperature to the design basis event is a function of the historical weather including the diurnal variations. This LAR is consistent with Braidwood Station's licensing basis (i.e., RG 1.27 Revision 2). The purpose of the UHS TS temperature limit is to restrict the initial UHS temperature such that the maximum UHS temperature (i.e., the temperature of the cooling water supplied to the plant safety systems from the UHS) experienced during the UHS design basis event would not exceed the design limit of the plant equipment cooled by the UHS. If the temperature of the cooling water supplied to the plant from the UHS exceeds the proposed TS limit, the existing Required Actions in the current TS would apply: Required Actions A.1 and A.2 would be entered concurrently, requiring both Braidwood Station Units 1 and 2 to be placed in Mode 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and Mode 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

The attached amendment request is subdivided as follows:

provides an evaluation of the proposed changes.

provides the current TS pages with the proposed changes indicated with markups.

provides the current TS Bases pages with the proposed changes indicated with markups. The TS bases pages are provided for information only and do not require NRG approval.

includes a summary of the regulatory commitments made in this request.

provides Braidwood Station Analysis, "Thermal Performance of Ultimate Heat Sink (UHS) During Postulated Loss of Coolant Accident" (ATD-0109 Revision 4).

provides the vendor data sheet for the Emergency Diesel Generator (EOG) Jacket Water Coolers.

provides the vendor data sheet for the Main Control Room Chiller Condenser.

In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"

paragraph (b), EGG is notifying the State of Illinois of this application for license amendment by transmitting a copy of this letter and its attachments to the designated State Official.

EGG requests approval of the proposed license amendment by August 19, 2015. Should the need for this amendment become urgent, EGG will request that the NRG reviews and processes this amendment on an expedited basis. Once approved, the amendment will be implemented within 30 days.

The proposed amendment has been reviewed by the Braidwood Station Plant Operations Review Committee and approved by the Nuclear Safety Review Board rn accordance with the requirements of the EGG Quality Assurance Program.

There are two regulatory commitments contained in this letter. These are described in.

Page 2 of 3

August 19, 2014 U.S. Nuclear Regulatory Commission Page 3 Should you have any questions concerning this letter, please contact Jessica Krejcie at (630) 657-2816.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 19th day of August 2014.

Respectfully, David M. Gullett Manager - Licensing Exelon Generation Company, LLC Attachments:

1. Evaluation of Proposed Changes

2. Mark-up of Proposed Technical Specification Page Change

3. Mark-up of Proposed Technical Specification Bases Pages Changes - For Information Only

4. Summary of the regulatory commitments made in this request

5. Braidwood Station Analysis, "Thermal Performance of Ultimate Heat Sink (UHS) During Postulated Loss of Coolant Accident" (ATD-0109 Revision 4)

6. Vendor Data Sheet for the Emergency Diesel Generator (EDG) Jacket Water Coolers

7. Vendor Data Sheet for the Main Control Room Chiller Condenser cc:

Illinois Emergency Management Agency - Division of Nuclear Safety NRC Regional Administrator-Region Ill NRC Senior Resident Inspector-Braidwood Station Page 3 of 3 Evaluation of Proposed Change Page 1 of 25

Subject:

Request for a License Amendment to Technical Specification 3.7.9, "Ultimate Heat Sink" 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration Determination 4.3 Conclusions

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

Evaluation of Proposed Change Page 2 of 25 1.0

SUMMARY

DESCRIPTION In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit" Exelon Generation Company, LLC (EGC) is requesting a change to the Technical Specifications (TS) of Facility Operating License Nos. NPF-72 and NPF-77 for Braidwood Station, Units 1 and 2 for the Ultimate Heat Sink (UHS). Currently, TS Surveillance Requirement (SR) 3.7.9.2 states: "Verify average water temperature of UHS is 100°F." If the UHS indicated temperature is > 100°F, TS 3.7.9 Required Actions A.1 and A.2 would be entered concurrently, requiring both Braidwood Station Units 1 and 2 to be placed in Mode 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and Mode 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

Recent summer meteorological conditions have resulted in the TS UHS temperature limit being challenged. These conditions include elevated air temperatures, high humidity, and low wind speed. Specifically, July 4 through July 6, 2012 brought unprecedented hot weather and drought conditions to the northern Illinois area resulting in sustained elevated UHS temperatures. Previous revisions of the UHS design analysis utilized weather data from 1948 to 1976. This UHS design analysis has been updated to include weather data through December 31, 2012, which includes the period when the maximum indicated cooling water temperature supplied to the plant from the cooling lake was observed (i.e., July 7, 2012).

Additionally, the analysis has been updated to include the latest revision of the UHS Heat Load analysis which incorporates the post-Measurement Uncertainty Recapture (MUR) power level.

The UHS design analysis methodology is based on Regulatory Guide (RG) 1.27, Revision 2, "Ultimate Heat Sink for Nuclear Power Plants," and NUREG-0693, "Analysis of Ultimate Heat Sink Cooling Ponds," dated November 1980.

This license amendment is being sought to allow the TS temperature limit of the cooling water supplied to the plant from the UHS to increase from 100°F to 102°F. The impact of the maximum UHS temperature experienced during a Design Basis Accident (DBA) event has been evaluated consistent with the Braidwood Station current licensing basis. This includes Regulatory Position C.1.b of RG 1.27, Revision 2 which states that the UHS temperature transient analysis should include diurnal variations for the total of the critical time period, based on examination of regional climatological measurements that are demonstrated to be representative of the site. While the analysis has been performed to analyze the diurnal variations, the proposed TS limit for the UHS temperature is proposed to increase from 100°F to 102°F, independent of time of day. This is consistent with the existing TS.

The evaluations and analyses performed to support the proposed license amendment demonstrate that the plant's safety related equipment will maintain its design function at the higher UHS temperature. Therefore, the proposed change has no adverse impact on Braidwood Station plant safety.

2.0 DETAILED DESCRIPTION 2.1 Proposed Changes The proposed changes to TS 3.7.9 are shown in Attachment 2 and are as follows:

The current TS SR 3.7.9.2 states:

Evaluation of Proposed Change Page 3 of 25 Verify average water temperature of UHS is 100°F.

The proposed TS SR 3.7.9.2 states:

Verify average water temperature of UHS is 102°F.

There are no proposed changes to the TS Required Actions, Completion Times, Frequency of SR performance, or any other portions of TS 3.7.9.

2.2 Background

The UHS consists of an excavated essential cooling pond integral with the main cooling pond.

The volume of the UHS is sized to permit the safe shutdown and cooldown of both Braidwood Station units for a minimum 30-day period during a DBA with no additional makeup water source. The UHS is designed to withstand the separate occurrence of either the safe shutdown earthquake or the probable maximum flood on the cooling pond. The UHS provides a heat sink for process and operating heat from safety related components during a transient or accident, as well as during normal operation. The UHS dissipates residual heat after reactor shutdown and after an accident through the cooling components of the Essential Service Water (SX)

System and the Component Cooling Water (CC) system, which are the principal systems at Braidwood Station that utilize the UHS to dissipate residual heat. The UHS also provides a source of emergency makeup water for the spent fuel pool and can provide water for fire protection equipment. Non-Essential Service Water (WS) pumps and Circulating Water (CW) pumps also take suction from the UHS during normal operation, however, operation for post-accident conditions is not considered since the WS and CW pumps are shut down before the UHS level reaches the minimum required water level for plant operation at 590 feet (Reference TS 3.7.9 and Reference 4).

The SX system takes suction from intake lines running from Safety Category I essential cooling pond to the auxiliary building where four SX pumps (two per unit) supply safety-related loads and components essential to safe shutdown. These include cubicle coolers, pump coolers, diesel engine coolers, CC heat exchangers, Reactor Containment Fan Coolers (RCFC) and chiller condensers. The CC system provides cooling water to the residual heat removal system, chemical and volume control system, reactor coolant system and process sampling system.

Updated Final Safety Analysis Report (UFSAR) Figure 2.4-47, "Essential Cooling Pond," shows the layout of the SX supply and discharge piping along with the Circulating Water supply and discharge piping. Relevant elevations for the cooling pond are also included in this figure.

The Braidwood Station limiting UHS DBA (i.e., that event that results in the maximum heat load on the UHS) is one unit undergoing post-Loss of Coolant Accident (LOCA) cooldown concurrent with a Loss of Offsite Power (LOOP), in conjunction with the other unaffected unit undergoing a safe non-accident shutdown. This scenario assumes the worst case single failure of the manmade structure (i.e., the Category II retaining dikes) that encloses the main cooling pond.

This limiting DBA includes three sources of heat energy to be transferred by the SX system after a LOCA: containment heat removal via the RCFCs, containment heat and reactor residual heat removal via the containment sumps, and Engineered Safety Features (ESF) equipment heat loads (e.g., ESF equipment coolers and room coolers).

The thermal performance of the Braidwood Station UHS was originally developed based on the initial UHS temperature of 98°F and meteorological conditions from the summer of 1955 for Evaluation of Proposed Change Page 4 of 25 highest temperature and summer of 1971 for highest evaporation. On June 13, 2000, the U.S.

NRC issued an amendment to increase the allowable UHS temperature from 98°F to 100°F.

The recent changes in meteorological conditions have resulted in the TS UHS temperature limit being challenged. Because of the recent change in meteorological conditions, such as increased temperature, the UHS DBA has been reassessed for an increase in initial temperature from 100°F to 102°F.

The analysis of the Braidwood Station UHS to determine the proposed TS limit and the associated post-DBA UHS temperature was a multi-step process. The steps included determining the critical time periods unique to the Braidwood Station UHS, gathering updated meteorological data, and screening the meteorological data to determine the most limiting sets of data. This information was used in the UHS analysis to determine UHS temperature and evaporation response by analyzing the combined effects of the most limiting sets of meteorological data with the DBA heat loads. Once the limiting post-DBA UHS temperature responses were determined, they were used (1) as input into the safety analysis to ensure responses remained within analyzed limits and (2) to evaluate performance margins of equipment cooled by the SX and CC systems. The evaporation response was assessed against the existing design analysis to ensure response remained within limits.

3.0 TECHNICAL EVALUATION

3.1 CRITICAL TIME PERIODS Consistent with RG 1.27, Revision 2, the UHS analysis considered the controlling parameters and critical time periods unique to the Braidwood Station specific UHS design. Critical time periods are those time periods in which the maximum lake temperature coincides with the most severe combination of controlling meteorological parameters. The design of the Braidwood Station UHS is a closed loop, where the SX cooling water exiting the plant combines with the UHS volume and traverses through the UHS while being cooled by the environment, prior to returning to the SX system suction. The key parameter of this design is the length of time the water remains in the UHS to dissipate heat to the environment; which is a function of the time it takes the water to transit the UHS before returning to the plant. The number of SX pumps in operation determines the transit time. Due to the different flow rates associated with the number of pumps in operation, the transit time differs. The transit time calculation takes into account effective lake volume which is the same regardless of number of SX pumps in operation.

The Braidwood Station SX system design allows up to four SX pumps to be operating at the same time. Each single SX pump services a full capacity essential service water loop capable of supplying all safety-related heat transfer equipment associated with that Unit. The normal SX system line up consists of one pump operating on each Unit. An ESF signal due to an accident on one Unit will result in one additional SX pump automatically starting on the accident Unit, therefore, the maximum number of SX pumps that are expected to be in operation at the start of the UHS DBA is three.

A fourth SX pump would be in operation if started manually by the operators later in the event, if needed for the Unit undergoing a normal shutdown. Although the critical time period for four SX pumps in operation was determined and evaluated as an input in the downstream UHS analysis, actual plant operation with four SX pumps in operation occurs infrequently and is Evaluation of Proposed Change Page 5 of 25 limited. This is discussed further in section 3.7. Based on the effective volume and flow rates, the critical time periods were determined and set to be 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for four SX pumps in operation, 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months for three SX pumps in operation and 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months for two SX pumps in operation.

3.2 UPDATED METEOROLOGICAL DATA The present UHS analysis of record utilizes meteorological data from 1948 to 1976, obtained from the National Weather Service (NWS) in Peoria, IL or Springfield, IL. To support this LAR, updated meteorological data was obtained spanning the period from 1976 through December 31, 2012.1 From January 1, 1990 through December 31, 2012, the meteorological data was a combination of data from the Peoria NWS and an onsite multi-level instrumented tower at Braidwood Station. All the meteorological data parameters collected were taken at one hour intervals from 1948 to 2012. This set of data was screened to identify and systematically correct any out of range or missing parameters.

3.3 METEOROLOGICAL DATA SCREENING TO DETERMINE LIMITING WEATHER PROFILES RG 1.27, Revision 2 describes a method for considering meteorological conditions in the design of the UHS. A synthetic weather file may be created using weather data from the critical time period based on the design of the UHS, the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and the worst 30 days, combined in this order.

In the Braidwood Station analysis, 64-years of meteorological data was analyzed in three-hour increments with a standard lake model, at the same initial conditions, to determine the set of data that resulted in the highest UHS water temperature (i.e., the set of hourly meteorological data that provided the most limiting conditions for the UHS to dissipate heat). This analysis was performed for each of the critical time periods identified as well as those required by RG 1.27 Revision 2 (i.e., 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months , and 30 days) and for the eight daily starting times (i.e., 12AM, 3 AM, 6 AM, 9AM, 12PM, 3 PM, 6 PM, 9 PM) used to model the diurnal lake behavior. A similar approach was used to determine the limiting set of data that resulted in the 30-day limiting evaporation.

The Braidwood Station UHS analysis created a series of synthetic weather files for use in the lake model. These files were created by combining the limiting meteorological data from each of the limiting critical times, with the worst 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period followed by the worst 30 day period.

The different synthetic weather files were input to the UHS analysis and represent the worst meteorological conditions for the UHS to dissipate heat under each SX pump operating scenario and associated daily start time. More details on the meteorological screening of data performed are included in Attachment 5, Section 2.0.

1 Meteorological data through December 2012 was used as this data was the latest available full set of parameters at the time of analysis performed in early 2014. The UHS temperature is an indication of environmental impacts on the UHS because the lake responds to environmental inputs. The UHS temperature did not exceed the TS limit during the summer of 2013 as it had during the summer of 2012, therefore, it is concluded that the data utilized through December 2012 is more severe and bounds the data from the summer of 2013.

Evaluation of Proposed Change Page 6 of 25 3.4 UHS ANALYSIS The purpose of this calculation is to determine the thermal response of the UHS to a DBA event under worst case meteorological conditions. In accordance with the Braidwood Station Design Basis, one unit is postulated to have a LOCA with LOOP, and the other unit is postulated to undergo normal shutdown. The dike of the Braidwood Station Lake is also assumed to have been breached leaving only the UHS available to support operation of the necessary equipment. The LAKET-PC computer program was used to determine the maximum UHS temperature and the maximum UHS inventory loss following a DBA using the proposed TS value of 102°F as an initial input. As specified in Regulatory Position 1 of RG 1.27, Revision 2, the diurnal variations of the UHS are accounted for in the temperature and evaporation response by varying the DBA start time.

The analysis modeled the heat dissipated by the UHS based on the synthetic weather file, specific to the accident starting time and number of SX pumps in operation, with the heat added due to one unit experiencing a DBA LOCA with LOOP and the other unit performing a simultaneous, safe non-accident shutdown. This same analysis was performed for a DBA starting at each of the eight daily starting times for two, three, and four SX pump operation.

The analysis determines the following parameters:

Maximum UHS temperature versus DBA start time Maximum UHS inventory loss or drawdown 3.4.1 Computer Model The computer program used to model the Braidwood Station UHS during the design basis event is LAKET-PC developed by Sargent and Lundy in 1976 as a one-dimensional thermal prediction model for bodies of water. The LAKET-PC computer program is utilized to determine the combined impact of decay heat, SX flowrate, initial UHS temperature, and meteorological conditions on the UHS response. The model assumes that the lake temperature is constant at any point along the plane perpendicular to the direction of the flow. The one dimensional model assumptions coerce the water body into an idealized rectangular channel. The movement of fluid through the one-dimensional channel is envisioned as a series of individual, distinct fluid segments. Each segment has an individual length and temperature, while the width and depth remain constant for all. The channel thus forms a queue of fluid segments, where additions are made at the inlet, and deletions are made at the outlet. Any segment that enters the channel will cause an equal amount to be expelled at the outlet. The program assumes that each segment is uniform in temperature, and each segment is allowed to react independently with the environment. The horizontal heat conduction for each segment is assumed to be negligible with respect to the heat rejection at the air-water interface and is ignored. Similarly, conductive heat loss at the water channel interface is conservatively ignored.

The methodology used in LAKET-PC is consistent with the thermal model presented in NUREG-0693 and the wind speed functions presented in Massachusetts Institute of Technology Report No. 161, "An Analytical and Experimental Study of Transient Cooling Ponds Behavior,"

dated January 1973, which is also referenced and cited in NUREG-0693.

Consistent with NUREG-0693, the LAKET-PC contributing components for the net heat transfer to the UHS are:

Evaluation of Proposed Change Page 7 of 25 Q = QSN + QAN - QBR - QE - QC + QRJ Where:

QSN = net incident short wave solar radiation QAN = net incident long wave atmospheric radiation QBR = net rate of long wave back radiation from the lake surface QE = net rate of heat loss due to evaporation QC = net rate of heat loss due to conduction and convection QRJ = net rate of heat rejected to the lake by the plant A comparison of the NUREG-0693 to LAKET-PC input parameters and equations is provided in Table 1.

Table 1: Comparison of Heat Load Equations NUREG- 0693 LAKET-PC QSN Measured value Calculated outside of LAKET-PC (documented in )

QAN 1.2x10-13(TA+460)6(1+0.17C2)

Calculated outside of LAKET-PC (documented in )

QBR 4.026x10-8(460+TS)4 4x10-8(460+TS)4 QE (eS - eA) F(w) approximated as: (TS-TD)F(w)

(eS - eA) F(w)

QC 0.26(TS-TA)F(w) 0.255(TS-TA)F(w)

QRJ Plant heat load input Plant heat load input Where:

C = fraction of sky covered by clouds (0.0-1.0)

TA = dry bulb air temperature (°F)

TS = water surface temperature (°F) eS = saturated vapor pressure at TS (mmHg) eA = vapor pressure at TA and relative humidity (mmHg)

=

2 2

000204

.0 2

0085

.0 255

.0

D S

T T

(mmHg/°F)

F(w) = wind function (LAKET-PC uses the Ryan wind function. The Ryan wind function is specifically formulated for lakes with heat load input from the plant. The use of the Ryan wind function is supported in NUREG-0693.)

The differences in the equations for QBR and QC are small. The terms QBR and Qc represent energy losses from the lake. Since the constants are smaller in LAKET-PC, the LAKET-PC is slightly conservative relative to the NUREG-0693 values (heat losses from the lake are modeled as slightly less in LAKET-PC).

Evaluation of Proposed Change Page 8 of 25 The table below provides details of the LAKET-PC modeling of the UHS with the size of the segments for each of the pumps running cases used in the analysis.

3.4.2 Wind Gradients LAKET-PC models wind gradients (as a function of the elevation above ground level) per the following equation:

3.0) 56

.6

(

15

.1 WINDZ knots mph WNDCOR

Where:

WNDCOR = wind correction factor to 2m above ground level WINDZ = measurement elevation above ground level [ft]

1.15 = conversion factor from knots to mph The wind speed extrapolation is a power law equation correcting the wind speed to an elevation of 2 meters (6.56 ft) above the ground level (the reference wind speed elevation used for wind functions in MIT Report No. 161). There are a variety of exponential factors that have been used over the years in the power law equation; LAKET-PC uses a conservatively bounding value of 0.3 for the exponent.

3.4.3 Ultimate Heat Sink Temperature Profile To account for the time of day at which the UHS DBA may start, eight cases on a 3-hour interval frequency at successive starting times were run for scenarios with two, three and four SX pumps running. The SX system at Braidwood Station is comprised of two trains, train A and train B, for each Unit. Each train includes one SX pump. The normal system line up consists of one pump operating on each Unit. An ESF signal due to an accident on one Unit will result in one additional SX pump automatically starting on the accident Unit, therefore, the maximum number of SX pumps that are expected to be in operation at the start of the UHS DBA is three.

Table 2: LAKET-PC Model Details 2 Pumps 3 Pumps 4 Pumps Total # of Segments 17 13 9

UHS Length (ft) 3,076 3,076 3,076 Segment Length (ft) 178 238 357 Eff. Area @ 590 ft (acre) 78.7 78.7 78.7 Conversion (ft2/acre) 43560 43560 43560 Area (ft2) 3,428,172 3,428,172 3,428,172 Segment Area @ 590 ft (ft2) 198,728 264,970 397,456 Segment Width (ft) 1,114 1,114 1,114 Segment Depth (ft) 5.8 5.8 5.8 Evaluation of Proposed Change Page 9 of 25 Due to system operating alignments, the four SX pumps case is not representative of normal operation or post-accident plant operations. During normal operation, an additional SX pump may be started in support of surveillance testing or pump start-up/shutdown operations for a short period of time, as required in support of plant activities. For post-accident conditions, a fourth SX pump would be in operation if started manually by the operators later in the event, if needed for the Unit undergoing a normal shutdown. Additionally, with four SX pumps in operation, the actual flow through the SX system will be limited by the hydraulic resistance of the SX system and be less than that analyzed in the calculation of transit time for the four SX pump case (i.e., the transit time calculated for the four SX pump case is conservative relative to the actual flow expected through the SX system due to hydraulic resistance). See Regulatory Commitment #2 which discusses the required changes to operating procedures to ensure SX operation with four pumps is limited.

The two and three-SX pumps cases were reviewed and the three SX pump case with the 3 AM starting time results in the limiting UHS temperature of 105.2°F. The profile for this limiting case is shown in Figure 1 and Figure 2. Based on the UHS temperature profile in Figure 1, the following temperatures were selected as values for the accident analysis and equipment evaluation:

104°F was used to determine the heat removal performance for the RCFCs. This is an input to the accident analyses that use the RCFCs for heat removal All equipment cooled by the UHS is evaluated for the limiting UHS temperature of 105.2°F.

The use of 104°F in the accident analyses is conservative because:

The UHS temperature remains below 104°F for the first 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months into the event.

The UHS temperature exceeds 104°F to a maximum of 105.2°F for a period less than 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months (hours 36-42)

From hour 42 onward, the UHS temperature remains below 104°F Except for the long term containment analyses, other accident analyses are evaluated for a time period less than 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months The long term containment analysis was re-performed (see section 3.6.1) and it was demonstrated that the containment pressures and temperatures have been significantly reduced from the calculated peak value at 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months after the event. At 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months the containment pressure is approximately 30 psi lower than the calculated peak and the containment atmosphere temperature is approximately 80°F lower than the calculated peak. Therefore, the increase in the UHS temperature above 104°F post 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months will not result in exceeding any design criteria related to post-LOCA containment requirements.

The UHS analysis also calculated the maximum drawdown for the UHS at the end of the 30-day period. The maximum calculated drawdown of 1.78 ft is lower than the maximum estimated drawdown (2.10 ft) evaluated in existing design analyses and is therefore acceptable.

Evaluation of Proposed Change Page 10 of 25 95 96 97 98 99 100 101 102 103 104 105 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Plant Inlet Temp (°F)

Days Following Accident UHS Temperature Profile - Limiting Case 3 SX Pumps - Event Start 3 AM 105.2°F Figure 1 Evaluation of Proposed Change Page 11 of 25 Figure 2 Evaluation of Proposed Change Page 12 of 25 3.5 EVALUATION OF EQUIPMENT A formal engineering evaluation has been completed to review the impact of the increase in the UHS TS maximum temperature of 102°F and the increase in the maximum post-accident SX inlet temperature to 105.2°F. This was completed by reviewing the evaluations and design calculations for equipment cooled by the SX and CC systems and developing simplified models which were validated against the results of the existing calculations. The models replicated the analyses contained in the existing evaluations and design calculations with the increased SX temperature. Resulting margins were reviewed and it was determined that equipment cooled by the SX and CC systems have adequate margin at the elevated UHS temperature without physical plant modifications. The specific component analyses impacted by this evaluation have been identified and will be updated in accordance with the existing Engineering Change processes and as outlined in Regulatory Commitment #1.

The heat load on the UHS is determined based on one unit undergoing a LOCA with a LOOP and the other unit going through a normal shutdown from maximum power. Heat loads for the UHS DBA event are shown in UFSAR Table 9.2-1 and were evaluated for the components listed in sections 3.5.1 through 3.5.5 with the exception of the Positive Displacement (PD)

Charging Pump Cubicle Cooler since the PD Charging pumps are not operated at Braidwood Station. While SX flow to the PD Charging Pump Room Cubicle Cooler is not isolated, the heat load in the room is insignificant with the pump idle. Note, the heat load for the Spent Fuel Pit Heat Exchanger includes the Spent Fuel Pool background heat load due to Spent Fuel Assemblies that are stored in the pool.

Note, all equipment that is cooled by the SX system is within the scope of the Generic Letter (GL) 89-13, "Service Water System Problems Affecting Safety-Related Equipment" program.

The information below describes the formal engineering evaluations performed to ensure that required plant equipment can continue to perform their design function at the elevated UHS temperature.

3.5.1 Pump Room Cubicle Coolers Pump room cubicle coolers are required to remove equipment heat from rooms with operating pumps. The formal engineering evaluation demonstrated that all cubicle coolers cooled by SX as listed below have margin of approximately 10% to 50% between the heat removed and the design heat load at design values for the SX cooling flow rates:

SX Pump Cubicle Coolers Residual Heat Removal (RHR) Pump Cubicle Coolers Safety Injection (SI) Pump Cubicle Coolers Charging (CV) Pump Cubicle Coolers Spent Fuel Pit Pump Room Cubicle Coolers Diesel Driven Auxiliary Feedwater (AF) Pump Room Cubicle Coolers Containment Spray (CS) Pump Room Cubicle Coolers These margins were evaluated under design conditions at the maximum post-accident SX inlet temperature to 105.2°F. To ensure margin, for the CS Pump Room Cubicle Cooler and the CV Pump Cubicle Coolers, a reduction in the Braidwood Station controlled tube plugging limits will be implemented. These changes will be implemented as part of Regulatory Commitment #1. In Evaluation of Proposed Change Page 13 of 25 addition to the margin described above, the pump room cubicle cooler evaluations conservatively apply a fouling factor for the water side of the cooler of 0.0025. This is conservative relative to the existing design fouling factor of 0.0015.

3.5.2 Oil Coolers The SX system provides cooling water to oil coolers for safety related pumps. The lube oil coolers for safety related pumps are small heat exchangers that are periodically cleaned and inspected in accordance with GL 89-13. As described above, (section 3.5) a simplified evaluation of the oil coolers was performed to review and identify margin with the maximum post-accident SX inlet temperature to 105.2°F. This evaluation concluded that approximately 10°F margin exists between the highest expected oil temperature and the limiting oil temperature for all oil coolers cooled by the SX system as listed below.

SX Pump Oil Coolers SI Pump Oil Coolers Diesel Driven AF Pump Gear Oil Cooler CV Centrifugal Pump Gear Oil Coolers Motor and Diesel Driven AF Pump Oil Coolers Diesel Driven AF Pump Right Angle Gear Lube Oil Cooler CV Centrifugal Pump Oil Coolers For the SX Pump Oil Coolers evaluation, a conservative condition with no SX cooling flow was assumed. Therefore, greater margin exists than that determined in this evaluation. All other Oil Coolers evaluations performed used design heat loads and the design SX cooling flow rates.

3.5.3 Engine Coolers The SX system provides cooling water to diesel engine cooling systems. Using the maximum post-accident SX inlet temperature to 105.2°F, engineering evaluations have been performed to confirm the cooling systems' capability to remove the design heat load. All engine coolers cooled by the SX system have been evaluated and demonstrated margin at the increased SX temperature. Evaluations of both the engine coolers identified below determined > 5°F margin available to their respective high jacket water temperature alarm setpoints.

Diesel Driven AF Pump Engine Closed Cycle Heat Exchanger Emergency Diesel Generator (EDG) Jacket Water Coolers The EDG Jacket Water Coolers evaluation was performed at the design SX cooling flow rate.

For the Diesel Driven AF pump engine closed cycle heat exchanger, the UHS temperature increase was evaluated crediting a higher SX cooling flow rate of 350 gpm in place of the design flow rate of 250 gpm and current tube plugging values. The design analysis for the current SX system flow model was reviewed and demonstrates a flow rate in excess of 500 gpm for the Diesel Driven AF pump engine closed cycle heat exchanger. The 350 gpm flow rate credited in the evaluation and required reduced tube plugging will become part of the new design analysis as part of Regulatory Commitment #1.

Evaluation of Proposed Change Page 14 of 25 3.5.4 Main Control Room Chiller Condenser The SX system provides cooling water to the Main Control Room (MCR) chiller condensers, which remove sensible and latent heat from the control room to ensure equipment operability and personnel occupancy. An engineering evaluation was performed for the increased UHS temperature of 105.2°F using design heat loads, design SX cooling flow rates and existing tube plugging values. The evaluation also used reduced fouling factor based on the as-found fouling factors of other heat exchangers in the NRC GL 89-13 program. The results show that the MCR chiller condenser is able to remove the heat load with over 25% margin at the maximum post-accident SX inlet temperature to 105.2°F. The existing design analysis of the MCR chiller condensers will be updated as part of Regulatory Commitment #1.

3.5.5 CC Heat Exchangers The CC system rejects heat to the UHS during normal plant operation and during accident conditions. Five different operating scenarios were evaluated to model the different plant configurations where the CC system is designed to operate (e.g., two units operating at power, one unit operating at power with the other unit shutdown, normal unit shutdown with other unit experiencing a LOCA). The CC heat exchangers were evaluated for increased normal operating UHS temperature of 102°F and increased post-DBA UHS temperature of 105.2°F using existing tube plugging values. The design basis scenario for the UHS DBA results in margin in excess of 50% for the CC heat exchangers.

Of the five operating scenarios evaluated, the two units operating at power and one unit operating at power with the other unit shutdown are numerically identical. These normal operating scenarios are more limiting than the design basis scenario described above and are the limiting configurations with respect to CC heat exchanger performance since the allowed maximum CC temperature for normal operations is 105°F which is lower than the allowed maximum CC temperature of 128°F for post-LOCA operations. These scenarios have greater than 30% margin. The existing design analysis of the CC Heat Exchangers will be updated as part of Regulatory Commitment #1.

The engineering evaluation of margin was performed using calculated fouling factors based on recent test data from the Unit 0 and Unit 2 CC heat exchangers. The recent test data measured temperature and flow through the heat exchangers using improved methods that allowed for a reduction in measurement uncertainty. While the Unit 1 CC heat exchanger has not yet been tested using the improved test method, the performance of the Unit 1 CC heat exchanger is expected to match or be bounded by the Unit 0 heat exchanger. This conclusion is based on the Unit 1 CC heat exchanger having fewer tubes plugged, being cleaned in February 2014, and having the same design as Unit 0.

3.5.6 Net Positive Suction Head (NPSH) Evaluations The NPSH for all safety related pumps which take suction from the UHS has been evaluated and found to remain acceptable for the higher UHS temperature. Sections 3.5.6.1 through 3.5.6.3 describe the evaluations of NPSH that were performed. Existing design analyses will be updated in accordance with Regulatory Commitment #1.

Evaluation of Proposed Change Page 15 of 25 3.5.6.1 SX Pump The existing SX pump analysis calculates a limiting (minimum) NPSH Available (NPSHA) at 100°F SX water temperature of 43.27 feet. For the maximum post-accident SX inlet temperature to 105.2°F, the vapor pressure will increase slightly resulting in a decrease of 0.38 feet in NPSHA. The new NPSHA will be 42.89 feet which still has significant margin above the NPSH Required (NPSHR) value of 36 feet at 28,000 gpm per pump.

3.5.6.2 SX Booster Pumps The SX booster pumps provide flow to various coolers associated with the diesel driven AF pumps. Normally, suction for the pumps is supplied by the SX pumps. The existing SX booster pump analysis calculates a limiting NPSHA of 26.62 feet. For the maximum post-accident SX inlet temperature to 105.2°F, a reduction in NPSHA of up to 0.38 feet is determined with a resulting NPSHA of 26.24 feet. This is greater than the NPSHR value of 23.31 feet.

3.5.6.3 Motor and Diesel Driven AF Pumps The AF pumps normally take suction from the Condensate Storage Tank (CST). If the CST is not available, the AF pumps can be supplied by the SX system. The NPSHA for the AF pumps is currently evaluated using the CST at a temperature of 120°F. The NPSHA with suction from the SX system is significantly higher than the NPSHA when taking suction from the CST.

Therefore, the NPSHA at the elevated UHS temperature of 105.2°F is bounded by the existing evaluation.

3.5.7 Diesel Driven AF Pump Operation during Loss of AC Power In the event of a complete loss of onsite AC electrical power (i.e., Station Blackout (SBO)); the Diesel Driven AF pump (i.e., the 'B' AF pump) is credited for steam generator inventory makeup.

The Braidwood Station licensing basis does not postulate an SBO to occur simultaneously with a UHS DBA. Therefore, water temperature experienced by the 'B' AF pump and its associated diesel driven SX booster pump at the start of an SBO event is limited to the proposed TS maximum temperature of 102°F.

During a SBO, the SX booster pump operates to provide cooling water to the 'B' AF pump's heat exchangers and coolers. Flow recirculates through the different heat exchangers and coolers back to the SX booster pump suction, resulting in isolation of the cooling water heat sinks and heat-up of the isolated SX booster pump cooling loop during the Braidwood Station SBO coping time of two hours.

The existing evaluation of NPSHA for this SBO recirculation mode was reviewed. The NPSHA evaluation utilized flow rates higher than the design flow rates. These higher flows support the higher cooling flow that is credited for the Diesel Driven Auxiliary Feedwater Pump Engine Closed Cycle Heat Exchanger (see section 3.5.3). The NPSHA determined in the existing evaluation is expected to decrease by up to 0.14 feet but will still remain higher than the NPSHR with the UHS temperature of 102°F.

The existing design analysis for this transient presently evaluates an initial UHS temperature of 102°F and concludes that the AF diesel engine closed cycle heat exchanger jacket water temperature will not exceed the high jacket water temperature trip setpoint during the two hour Evaluation of Proposed Change Page 16 of 25 SBO coping time. Therefore, the current design analysis remains applicable with the proposed increase in TS UHS temperature.

3.5.8 GL 96-06 Considerations U.S. Nuclear Regulatory Commission Generic Letter 96-06, "Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions," indicated concerns for possible water hammer events following either a LOCA or a Main Steam Line Break (MSLB) concurrent with a LOOP. The period of interest for the NRC GL 96-06 concern of water hammer is the first few minutes post-accident, while the pumps and fans are restarting following load shed. During this time, as shown in the temperature profile in Figure 1, the actual UHS temperature is below 102°F. The current design analysis reviewed the impact with an increase in SX temperature of 102°F and determined that a slight increase in fluid temperature will not result in significant changes to the amount of voiding and thus negligible impacts to void collapse and the existing results of this analysis.

3.5.9 Spent Fuel Pool Cooling The spent fuel pool cooling heat exchanger is cooled by the CC system. Since the CC Heat Exchangers have been evaluated to be capable of removing the required heat load at the increased UHS temperature of 102°F during normal operation (see section 3.5.5), the spent fuel pool heat exchanger will continue to be able to perform its required design function. During a UHS DBA, the CC Heat Exchanger is also analyzed at 105.2°F and is capable of removing the required spent fuel pool heat exchanger heat load. Thus, the spent fuel pool cooling heat exchanger will remain capable of removing the required heat load ensuring the maximum pool bulk temperature is below the bounds of the design analysis.

3.5.10 Fire Protection The Fire Protection pumps take suction from the Braidwood Station main cooling pond. The increase in UHS temperature has been evaluated not to impact the function of the fire protection system.

3.5.11 Conclusions The results of the equipment analyses demonstrated that, with the increased SX temperature, margins in the design analyses were present which confirmed that the various components serviced by the SX and CC systems are acceptable without physical modification.

3.6 ACCIDENT ANALYSES The accident analyses have been evaluated or reanalyzed for the increased UHS temperature.

The affected analyses were analyzed for a UHS temperature of 104°F, as described in section 3.4.3. For non-LOCA analyses, using the temperature of 104°F is conservative because the UHS temperature analysis (Figures 1 and 2) show that the SX temperature does not approach 105.2°F until about 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months after the event and these analyses are analyzed for a duration significantly less than 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . These analyses have been performed at the current licensed power level, including the Measurement Uncertainty Recapture (MUR) Uprate.

Evaluation of Proposed Change Page 17 of 25 The following analyses have been reviewed and are not impacted by the UHS temperature increase:

LOCA Analysis - Large Break - Best Estimate LOCA Analysis - Small Break LOCA Long Term Cooling/Post LOCA Boric Acid Precipitation LOCA Forces Evaluation of Auxiliary Equipment, Balance of Plant (BOP) and Nuclear Steam Supply System (NSSS) Design Transients Control Systems Operability / Margin to Trip/Component Sizing evaluations which reviewed the control and protection system setpoints to verify that the system capacities do not change Evaluation of the Cold Overpressure Mitigation System / Low Temperature Overpressure Protection System which protects the reactor vessel from potentially being exposed to conditions of fast propagating brittle fracture caused by design basis mass and heat input transients at low temperature operation Steam Generator Tube Rupture (SGTR) and SGTR Radiological/Doses I&C Systems / Equipment Qualification evaluation which considered the impact to the design, configuration, qualification and performance of the safety-related electrical components and systems Evaluation of the Containment Sump / GSI-191 analyses which included the effects of post-LOCA sump chemistry and composition on components downstream of the containment sump Evaluation of the Reactor Coolant Pump and Reactor Coolant Pump Motor limits on maximum CC and seal injection temperatures The following analyses are impacted by the UHS temperature increase:

LOCA Long Term/Short Term Mass and Energy (Containment Integrity)

MSLB Inside Containment/Outside Containment Mass and Energy - Dose Steam Release (Containment Integrity)

While these two analyses are not directly affected by the UHS temperature increase, the heat removal performance for the RCFCs is used in the analysis and is affected by the UHS temperature increase because the RCFCs reject containment heat to the UHS.

3.6.1 LOCA Long Term/Short Term Mass and Energy (Containment Integrity)

The Braidwood Station Units were reanalyzed to assess an increase in the water temperature of the UHS to 104°F (see section 3.4.3). The largest impact on the LOCA containment analysis from the elevated UHS temperature would be the reduction of the performance of the RCFCs resulting in higher containment pressures for these events and reduced cooling by the CC heat exchangers.

Other changes were made to the LOCA containment analysis not related to the UHS temperature change. The analysis incorporated updated containment spray and safety injected flow rates. Additional changes to correct open items were 1) correction for the SG tube material to have the correct density and specific heat (Reference NSAL 14-2) 2) correction to the SATAN78 power shape selection option to select a chopped cosine power shape and Evaluation of Proposed Change Page 18 of 25

3) incorporation of an NRC approved model (Reference 3) for drift flux and break flow with inertia. In general, containment analysis peak pressure results would be expected to increase due to the proposed increase in UHS temperature and the associated impact to performance of the RCFCs. However, the SX temperature change coupled with the other changes described above resulted in peak pressure values similar to the current design analysis.

Results show that the new calculated peak pressure is below the existing Technical Specification Pa values of 42.8 psig for Unit 1 and 38.4 psig for Unit 2.

The following table summarizes the results.

Table 3: Containment Analysis Results Break Location Plant Containment Peak Pressure for increased SX temperature (psig)

TS Pa (psig)

Double Ended Hot Leg (DEHL)

UNIT 1 42.1 42.8 UNIT 2 37.7 38.4 Double Ended Pump Suction (DEPS)

UNIT 1 42.1 42.8 UNIT 2 38.4 38.4 3.6.2 MSLB Inside Containment Mass and Energy (Containment Integrity)

The increase in SX temperature due to the elevated UHS temperature has an impact on the performance of the RCFCs, resulting in higher containment pressures and temperatures during the MSLB event. Therefore, the MSLB cases were reanalyzed for the increased UHS temperature. The results of all MSLB analyses at the elevated UHS temperature are bounded by the current design basis calculations.

3.6.2.1 MSLB Peak Containment Temperatures The peak temperature response of all the Unit 1 MSLB cases analyzed is 322.1°F. This is lower than the maximum Unit 1 temperature of 333.6°F from the current design basis analyses. The peak temperature response of all the Unit 2 MSLB cases analyzed is 318.9°F. This is lower than the maximum Unit 2 temperature of 326.3°F from the current design basis analyses.

Evaluation of Proposed Change Page 19 of 25 These peak temperatures were for a 1.0 ft2 small double-end rupture (DER) break at 100%

initial power, with a single failure of the main steam isolation valve in the faulted loop, with offsite power available, and 0% revaporization of the condensed liquid on the containment surfaces.

3.6.2.2 MSLB Peak Containment Pressures The peak pressure response of all the MSLB cases for Unit 1 analyzed is 34.5 psig. The peak pressure response of all the MSLB cases for Unit 2 is 34.4 psig. Both cases for each Unit are well below the 50 psig design pressure acceptance criterion. The peak pressures for Unit 1 was calculated for a 0.90 ft2 split break at 30% initial power, with a single failure of the main steam isolation valve in the faulted loop, and with offsite power available. The peak pressures for Unit 2 was calculated for a 0.83 ft2 split break at 30% initial power, with a single failure of the main steam isolation valve in the faulted loop, and with offsite power available.

3.6.2.3 MSLB Composite Temperature and Pressure Profile (Unit 1 and Unit 2)

The composite containment temperature response for Unit 1 and Unit 2 were reviewed and were compared to the design Environmental Qualification (EQ) temperature profile. The revised temperature profile is enveloped by the existing design EQ profile. For EQ pressure, the EQ profile uses a flat 50 psig curve until 1200 seconds into the event and then a saturated pressure model after 1200 seconds. Therefore, the results of the analyses do not change the EQ curve.

3.7 OPERATOR ACTIONS Operators read and record the UHS temperature on a shiftly basis in accordance with station procedures. Each unit has an operator that monitors SX pump discharge temperature. The control room indication for cooling water temperature is readily available from the plant process computer at each of the units computer consoles and main control board indications. Unit 1 and Unit 2 control room operators are both required to determine and record the SX pump temperature for the running SX trains for their respective units as part of their shiftly surveillance. The control room operator is required to record and compare the average SX pump discharge temperature from both units to the limits in TS SR 3.7.9.2. The SX pump discharge temperature (i.e., used to verify the TS SR 3.7.9.2 limit) is the average of each unit's running SX pump discharge temperature and could result in both units entering the required actions at the same time should SX temperature exceed the TS limit. In the event that there is an increase in UHS temperature such that a high alarm is received on the SX pump discharge temperature (i.e., high alarm setpoint is 96°F), operators log the SX pump discharge temperature more frequently. Operators will log the operating SX pumps discharge temperature hourly when the high alarm setpoint temperature of 96°F is reached. In the event that TS SR 3.7.9.2 limits are exceeded, both units would declare the UHS inoperable and follow the actions of TS 3.7.9 as currently required.

No operator actions regarding temperature monitoring will change as a result of the proposed licensed amendment. Existing Braidwood Station procedures presently provide guidance for high cooling lake temperatures including action to shutdown both units if temperatures cannot be maintained within TS limits.

The revised DBA for the UHS has determined that the limiting critical time period is that associated with four pump operation (i.e., the maximum UHS temperature reached with four SX Evaluation of Proposed Change Page 20 of 25 pump operation exceeds the maximum UHS temperature in which the evaluation of equipment was completed (105.2°F)). Because the maximum temperature in which the equipment has been evaluated is exceeded with four SX pump operation, it is necessary to limit operation with four SX pumps in the event of the DBA (i.e., LOCA with LOOP on one unit and loss of the main dike). Operation with four SX pumps is not required for normal operation or to respond to a design basis event. However, existing procedures currently allows operation with four SX pumps for operational flexibility (see section 3.4.3). The analysis demonstrates that four pump operation is only limited following loss of the manmade structure (dike) with coincident LOCA and LOOP on one unit with the safe non-accident shutdown of the other unit. For this event, four SX pumps are not required. The procedures which control response to this event will be revised prior to LAR approval to reflect the limitations of operation with four pumps (Regulatory Commitment #2).

3.8 MEASUREMENT UNCERTAINTY To ensure the requested temperature limit is not exceeded, instrument uncertainty associated with the measurement of the UHS average water temperature is addressed in the surveillance procedures that are used to demonstrate compliance with the TS limit. The specific procedures are: 1BwOSR 0.1-1,2,3, 1BwOSR 0.1-4, 2BwOSR 0.1-1,2,3, and 2BwOSR 0.1-4.

In accordance with the Braidwood Station Technical Specifications Bases B 3.7.9, the average water temperature of the UHS is measured at the discharge of an SX pump. The surveillance procedures require that if the temperature of any operating SX pump exceeds 97°F, a precision temperature instrument, procured for this application, be used to verify the temperature. The difference between 97°F and the proposed Surveillance Requirement limit of less than 102°F is greater than the calculated instrument uncertainties associated with the installed instrumentation. Highly accurate measurement is accomplished by inserting the probe of the precision thermometer into spare thermowells adjacent to the installed instrumentation. The uncertainty of this precision thermometer is a maximum of 0.07F. This instrumentation is valid for a calibrated range of up to 212°F, which bounds the new proposed maximum UHS temperature of 102°F. As part of the activities to implement the approved LAR, the temperature limit specified in the applicable surveillance procedures will be revised to 101.9°F to account for the uncertainty associated with this instrument.

4.0 REGULATORY EVALUATION

4.1 APPLICABLE REGULATORY REQUIREMENTS/CRITERIA The design of the UHS satisfies the requirements of 10 CFR 50.36, "Technical Specifications,"

paragraph (c)(2)(ii), Criterion 3. This criterion states the following:

(ii) A Technical Specification Limiting Condition for Operation (TS LCO) of a nuclear reactor must be established for each item meeting one or more of the following criteria:

Criterion 3. A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

Evaluation of Proposed Change Page 21 of 25 The proposed change does not change the design function or purpose of the UHS, therefore, Criterion 3 of 10 CFR 50.36(c)(2)(ii) continues to be met.

General Design Criteria 2, "Design bases for protection against natural phenomena," and General Design Criteria 44, "Cooling water," of Appendix A to 10 CFR Part 50, "General Design Criteria for Nuclear Power Plants," provides design considerations for the UHS. RG 1.27, "Ultimate Heat Sink for Nuclear Power Plants," Revision 2, dated January 1976, provides an acceptable approach for satisfying these criteria. The basis provided in RG 1.27, Revision 2, was employed for the temperature analysis of the Braidwood Station UHS.

General Design Criteria 5, Sharing of structures, systems and components, of Appendix A to 10 CFR Part 50 also provides design criteria applicable to the UHS, a shared system between Braidwood Station Units 1 and 2. The proposed change, including the re-analysis of the UHS DBA, was evaluated consistent with the existing methodology which considers a DBA event (i.e., a LOCA with LOOP) along with the safe non-accident shutdown and cooldown of the opposite unit. Therefore, GDC 5 criteria continue to be met by the reanalysis of the UHS DBA at the elevated initial UHS temperature of 102°F.

The proposed change continues to ensure that the plant's safety related equipment will maintain its design function at the higher UHS temperature. Therefore, there is no adverse impact of this change on Braidwood Station plant safety.

4.2 NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Exelon Generation Company, LLC (EGC) is requesting a change to the Technical Specifications (TS) of Facility Operating License Nos. NPF-72 and NPF-77 for Braidwood Station, Units 1 and 2.

The Ultimate Heat Sink (UHS) for Braidwood Station, Units 1 and 2 provides a heat sink for processing and operating heat from safety related components during a transient or accident, as well as during normal operation. This is done by utilizing the Essential Service Water (SX)

System and the Component Cooling Water (CC) system. The UHS consists of an excavated essential cooling pond integral with the main cooling pond. The volume of the excavated essential cooling pond is sized to permit the safe shutdown and cooldown of both Braidwood Station units for a 30 day period, including a design basis event with no additional makeup water source. As discussed in the Braidwood Station Updated Final Safety Analysis Report (UFSAR), the design basis event for the Braidwood Station UHS is a Loss of Coolant Accident (LOCA) coincident with a Loss of Offsite Power (LOOP) in one unit, in conjunction with a normal shutdown of the other unit. The UHS provides a heat sink for process and operating heat from safety-related components during the UHS design basis event.

Currently, Surveillance Requirement (SR) 3.7.9.2 verifies the cooling water temperature supplied to the plant from the UHS is 100°F. If the temperature of the cooling water supplied to the plant from the UHS exceeds 100°F, the UHS must be declared inoperable in accordance with TS 3.7.9. Additionally, TS 3.7.9 Required Action A.1 requires that both units be placed in Mode 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and Required Action A.2 requires that both units be placed in Mode 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

Evaluation of Proposed Change Page 22 of 25 The proposed change modifies the acceptance criterion in SR 3.7.9.2. The current TS SR 3.7.9.2 states: "Verify average water temperature of UHS is 100°F." The proposed TS SR 3.7.9.2 states: "Verify average water temperature of UHS is 102°F." There are no proposed changes to the TS Required Actions, Completion Times, Frequency of SR performance, or any other portions of TS 3.7.9.

The evaluations and analyses performed to support the proposed license amendment demonstrate that the plant's safety related equipment will maintain its design function at the higher UHS temperature.

According to 10 CFR 50.92, "Issuance of amendment," paragraph (c), a proposed amendment to an operating license involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated;

2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or

3) Involve a significant reduction in a margin of safety.

In support of this determination, an evaluation of each of the three criteria set forth in 10 CFR 50.92 is provided below:

1.

Does the Proposed Change Involve a Significant Increase in the Probability or Consequences of an Accident Previously Evaluated?

Response: No The likelihood of a malfunction of any systems, structures or components (SSCs) supported by the UHS is not significantly increased by increasing the allowable Ultimate Heat Sink (UHS) temperature from 100°F to 102°F. The UHS provides a heat sink for process and operating heat from safety related components during a transient or accident, as well as during normal operation. The proposed change does not make any physical changes to any plant SSCs, nor does it alter any of the assumptions or conditions upon which the UHS is designed. The UHS is not an initiator of any analyzed accident. All equipment supported by the UHS has been evaluated to demonstrate that their performance and operation remains as described in the UFSAR with no increase in probability of failure or malfunction.

The SSCs credited to mitigate the consequences of postulated design basis accidents remain capable of performing their design basis function. The change in maximum UHS temperature has been evaluated using the UFSAR described methods to demonstrate that the UHS remains capable of removing normal operating and post-accident heat. The change in UHS temperature and resulting containment response following a postulated design basis accident has been demonstrated to not be impacted. Additionally, all the UHS supported equipment, credited in the accident analysis to mitigate an accident, has been shown to continue to perform their design function as described in the UFSAR.

Evaluation of Proposed Change Page 23 of 25 Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2.

Does the Proposed Change Create the Possibility of a New or Different Kind of Accident from any Accident Previously Evaluated?

Response: No The proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated. The proposed change does not introduce any new modes of plant operation, change the design function of any SSC, change the mode of operation of any SSC, or change any actions required when the TS limit is exceeded. There are no new equipment failure modes or malfunctions created as affected SSCs continue to operate in the same manner as previously evaluated and have been evaluated to perform as designed at the increased UHS temperature and as assumed in the accident analysis. Additionally, accident initiators remain as described in the UFSAR and no new accident initiators are postulated as a result of the increase in UHS temperature.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3.

Does the Proposed Change Involve a Significant Reduction in a Margin of Safety?

Response: No The proposed change continues to ensure that the maximum temperature of the cooling water supplied to the plant SSCs during a UHS design basis event remains within the evaluated equipment limits and capabilities assumed in the accident analysis. The proposed change does not result in any changes to plant equipment function, including setpoints and actuations. All equipment will function as designed in the plant safety analysis without any physical modifications. The proposed change does not alter a limiting condition for operation, limiting safety system setting, or safety limit specified in the Technical Specifications.

The proposed change does not adversely impact the UHS inventory required to be available for the UFSAR described design basis accident involving the worst case 30-day period including losses for evaporation and seepage to support safe shutdown and cooldown of both Braidwood Station units. Additionally, the structural integrity of the UHS is not impacted and remains acceptable following the change, thereby ensuring that the assumptions for both UHS temperature and inventory remain valid.

Therefore, since there is no adverse impact of this change on the Braidwood Station safety analysis, there is no reduction in the margin of safety of the plant.

4.3 CONCLUSION

S In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Evaluation of Proposed Change Page 24 of 25

5.0 ENVIRONMENTAL CONSIDERATION

EGC has evaluated this proposed operating license amendment consistent with the criteria for identification of licensing and regulatory actions requiring environmental assessment in accordance with 10 CFR 51.21, "Criteria for and identification of licensing and regulatory actions requiring environmental assessments." EGC has determined that this proposed change meets the criteria for a categorical exclusion set forth in paragraph (c)(9) of 10 CFR 51.22, "Criterion or categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review," and as such, has determined that no irreversible consequences exist in accordance with paragraph (b) of 10 CFR 50.92, "Issuance of amendment." This determination is based on the fact that this change is being proposed as an amendment to the license issued pursuant to 10 CFR 50, "Domestic Licensing of Production and Utilization Facilities," which changes a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, "Standards for Protection Against Radiation," or which changes an inspection or a surveillance requirement, and the amendment meets the following specific criteria:

(i)

The amendment involves no significant hazards consideration.

As demonstrated in Section 4.2, "No Significant Hazards Consideration," the proposed change does not involve any significant hazards consideration.

(ii)

There is no significant change in the types or significant increase in the amounts of any effluent that may be released offsite.

The proposed change does not result in an increase in power level, does not increase the production nor alter the flow path or method of disposal of radioactive waste or byproducts. The proposed change continues to ensure that the plant's safety related equipment will maintain its design function at the higher UHS temperature. Therefore, there is no impact of this change on Braidwood Station safety analyses including the consequences of such events.

Based on the above evaluation, the proposed change will not result in a significant change in the types or significant increase in the amounts of any effluent released offsite.

(iii)

There is no significant increase in individual or cumulative occupational radiation exposure.

There is no net increase in individual or cumulative occupational radiation exposure due to the proposed change. The proposed action will not change the level of controls or methodology used for processing of radioactive effluents or handling of solid radioactive waste, nor will the proposed action result in any change in the normal radiation levels within the plant.

Based on the above information, there will be no increase in individual or cumulative occupational radiation exposure resulting from this change.

Evaluation of Proposed Change Page 25 of 25

6.0 REFERENCES

1. Letter from Daniel J. Enright (EGC) to U.S. Nuclear Regulatory Commission, "Request for Enforcement Discretion for Technical Specification 3.7.9 'Ultimate Heat Sink,'" dated July 10, 2012

2. Engineering Change (EC) Evaluation 396478 Revision 0, "Support Analyses for the License Amendment Request to Raise the Maximum UHS Temperature for the UHS in TS LCO 3.7.9."

3. WCAP-10325-P-A, "Westinghouse LOCA Mass and Energy Release Model for Containment Design March 1979 Version," dated May, 1983

4. Procedure 0BwOA ENV-3, "Braidwood Cooling Lake Low Level Unit 0," Revision 102 Mark-up of Proposed Technical Specification Page Change

UHS 3.7.9 BRAIDWOOD UNITS 1 & 2 3.7.9 1 Amendment 165/165 3.7 PLANT SYSTEMS 3.7.9 Ultimate Heat Sink (UHS)

LCO 3.7.9 The UHS shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. UHS inoperable.

A.1 Be in MODE 3.

AND A.2 Be in MODE 5.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months 36 hours SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.9.1 Verify water level of UHS is 590 ft Mean Sea Level (MSL).

In accordance with the Surveillance Frequency Control Program SR 3.7.9.2 Verify average water temperature of UHS is 100102F.

In accordance with the Surveillance Frequency Control Program SR 3.7.9.3 Verify bottom level of UHS is 584 ft MSL.

In accordance with the Surveillance Frequency Control Program Mark-up of Proposed Technical Specification Bases Pages Changes -

For Information Only

UHS B 3.7.9 BRAIDWOOD UNITS 1 & 2 B 3.7.9 1 Revision 0 B 3.7 PLANT SYSTEMS B 3.7.9 Ultimate Heat Sink (UHS)

BASES BACKGROUND The UHS provides a heat sink for processing and operating heat from safety related components during a transient or accident, as well as during normal operation. This is done by utilizing the Essential Service Water (SX) System and the Component Cooling Water (CC) System.

The UHS consists of an excavated essential cooling pond integral with the main cooling pond, and the piping and valves connecting the pond with the SX System pumps. The UHS is described in UFSAR, Section 9.2.5 (Ref. 1). The two principal functions of the UHS are the dissipation of residual heat after reactor shutdown, and dissipation of residual heat after an accident.

The basic performance requirements are that a 30 day supply of water be available, and that the design basis temperatures of safety related equipment not be exceeded.

The UHS is sufficiently oversized to permit a minimum of 30 days of operation with no makeup.

Additional information on the design and operation of the system, along with a list of components served, can be found in Reference 1.

UHS B 3.7.9 BRAIDWOOD UNITS 1 & 2 B 3.7.9 2 Revision 16 BASES APPLICABLE The UHS is the sink for heat removed from the reactor core SAFETY ANALYSES following all accidents and anticipated operational occurrences in which the unit is cooled down and placed on Residual Heat Removal (RHR) operation. The UHS is also the normal heat sink for condenser cooling via the Circulating Water System. Unit operation at full power represents the UHS maximum heat load. Its maximum post accident heat load occurs 20 minutes after a design basis Loss Of Coolant Accident (LOCA). Near this time, the unit switches from injection to recirculation and the containment cooling systems and RHR are required to remove the core decay heat.

The operating limits are based on conservative heat transfer analyses for the worst case LOCA. Reference 1 provides the details of the assumptions used in the analysis, which include worst expected meteorological conditions, conservative uncertainties when calculating decay heat, and worst case single active failure (e.g., single failure of a manmade structure). The UHS is designed in accordance with Regulatory Guide 1.27 (Ref. 2), which requires a 30 day supply of cooling water in the UHS.

The UHS satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO The UHS is required to be OPERABLE and is considered OPERABLE if it contains a sufficient volume of water at or below the maximum temperature that would allow the SX System to operate for at least 30 days following the design basis LOCA without the loss of Net Positive Suction Head (NPSH),

and without exceeding the maximum design temperature of the equipment served by the SX System. To meet this condition, the UHS temperature should not exceed 1020F and the level should not fall below 590 ft mean sea level during normal unit operation.

APPLICABILITY In MODES 1, 2, 3, and 4, the UHS is required to support the OPERABILITY of the equipment serviced by the UHS and required to be OPERABLE in these MODES.

In MODE 5 or 6, the OPERABILITY requirements of the UHS are determined by the systems it supports.

UHS B 3.7.9 BRAIDWOOD UNITS 1 & 2 B 3.7.9 3 Revision 85 BASES ACTIONS A.1 and A.2 If the UHS is inoperable, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.7.9.1 REQUIREMENTS This SR verifies that adequate long term (30 day) cooling can be maintained. The specified level also ensures that sufficient NPSH is available to operate the SX pumps. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Frequency is based on operating experience related to trending of the parameter variations during the applicable MODES. This SR verifies that the UHS water level is 590 ft mean sea level United States Geological Society datum.

SR 3.7.9.2 This SR verifies that the SX System is available to cool the CC System to at least its maximum design temperature with the maximum accident or normal design heat loads for 30 days following a Design Basis Accident. This SR verifies that the average water temperature of the UHS is 102ºF, as measured at the discharge of an SX pump. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. This SR verifies that the average water temperature of the UHS is 100F, as measured at the discharge of an SX pump.

UHS B 3.7.9 BRAIDWOOD UNITS 1 & 2 B 3.7.9 4 Revision 85 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.7.9.3 This surveillance verifies that the UHS contains adequate storage volume to supply the required design basis inventory to support the function of the essential service water system. SR 3.7.9.1 verifies the contained volume of the UHS, while this SR verifies that the UHS, if filled to the depth required by SR 3.7.9.1, can supply the water required to support the safety function of the system.

SR 3.7.9.3 assures that the bottom elevation of the UHS is less than or equal to 584 ft Mean Sea Level (MSL). This surveillance is performed by means of a hydrographic survey.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES

1.

UFSAR, Section 9.2.5.

2.

Regulatory Guide 1.27.

Summary of Regulatory Commitments Page 1 of 1 COMMITMENT COMMITTED DATE OR "OUTAGE" COMMITMENT TYPE ONE-TIME ACTION (Yes/No)

PROGRAMMATIC (Yes/No)

Regulatory Commitment #1: Existing design analyses supporting implementation of the proposed TS SR 3.7.9.2 increased UHS temperature will be updated prior to NRC approval of the license amendment Prior to NRC approval of the license amendment request Yes No Regulatory Commitment #2: Operating procedures associated with the response to the loss of dike event concurrent with a LOCA and LOOP which are impacted by limitation with four SX pump operation will be updated prior to NRC approval of the license amendment Prior to NRC approval of the license amendment request Yes No Braidwood Station Analysis, Thermal Performance of Ultimate Heat Sink (UHS)

During Postulated Loss of Coolant Accident (ATD-0109 Revision 4)

Desi sis Cover Sheet CC-AA-309-1001 Revision 8 Design Analysis Last Page No.* Attachment F, Page F3 Analysis No.:'

ATD -0109 Revision: 2 4 Major [gl Minor O

Title:

3 Thermal Performance of UHS During Postulated Loss of Coolant Accident EC/ECR No.:

EC 396478 Revision:"

0 Station(s): 1 Unit No.:*

Discipline:

Descrip. Code/Keyword: 16 Safety/QA Class: 11 System Code: "

Structure: "

Braidwood 112 M,MED UHS, M03, M13 Safety Related sx N/A Component(s}:,.

N/A CONTROLLED DOCUMENT REFERENCES" Document No.:

From/To Document No.:

From/To ATD-0063 From MAD 83-0239 From BRW-99-0481-M From Is this Design Analysis Safeguards Information? *e Does this Design Analysis contain Unverified Assumptions? 11 This Design Analysis SUPERCEDES: "

BRW-00-0018-M Yes 0 No ldSl Yes 0 No L2:l If yes, see SY-AA-101-106 If yes, A Tl/AR#: ____ __,

in its entirety.

Description of Revision (list changed pages when all pages of original analysis were not changed):,.

This revision increases the initial Ultimate Heat Sink (UHS) temperature to 102°F. The weather data is updated to include latest weather from 1948 to 2012, and the UHS heatload is updated per the latest revision of ATD-0063.

All pages revised (Main Body 19 pages+ OAR Checklist 3 pages+ Attachments 107 pages, Total of 129 pages)

Preparer: 26 Pawel Kut - S&L

~-

o?-211-1 Print Name Si n Name Date Method of Review: 21 Detailed Review ldSl Alternate Calculations (attached) 0 Testing 0 Reviewer: 22 Review Notes: "

(For External Analyses Only)

External Approver: 2*

Independent review ldSl Robert J. Peterson - S&L Print Name

~xelon Reviewer: G'/fJ\\//tlJNI (>Af./ICA Print Name Peer review D Independent 3'd Party Review Reqd? "'

Yes.2S:f' Exelon Approver: " Cto<JQ.R. /..< 1) h1 /~a Pnnt Name f~

no,!l'i

ATTACHMENT 2 CC-AA-103-1003 Revision 9 Page 7of11 Owner's Acceptance Review Checklist for External Design Analyses Page 1of3 Design Analysis No.: _._A..... r

......... b..... -_O_l0

____ 9 _____ _

Rev:

4-No Question Instructions and Guidance Yes l No I NIA 1

Do assumptions have All Assumptions should be stated in clear terms with enough l.!f D D sufficient documented justification to confirm that the assumption is conservative.

rationale?

For example, 1) the exact value of a particular parameter may not be known or that parameter may be known to vary over the range of conditions covered by the Calculation. It is appropriate to represent or bound the parameter with an assumed value. 2) The predicted performance of a specific piece of equipment in lieu of actual test data. It is appropriate to use the documented opinion/position of a recognized expert on that equipment to represent predicted equipment performance.

Consideration should also be given as to any qualification testing that may be needed to validate the Assumptions. Ask yourself, would you provide more justification if you were performing this analysis? If yes, the rationale is likely incomplete.

./

Are assumptions Ensure the documentation for source and rationale for the l.!l D D 2

compatible with the assumption supports the way the plant is currently or will be Svfp\\lrt5' way the plant is operated post change and they are not in conflict with any t-\\," u \\tS operated and with the design parameters. If the Analysis purpose is to establish a licensing basis?

new licensing basis, this question can be answered yes, if the LA~

assumption supports that new basis.

3 Do all unverified If there are unverified assumptions without a tracking D D l!'.r assumptions have a mechanism indicated, then create the tracking item either s VfPurti-*

tracking and closure through an ATI or a work order attached to the implementing mechanism in place?

WO. Due dates for these actions need to support verification tl,~ u HS prior to the analysis becoming operational or the resultant l-A:_~

plant chanqe beinq op authorized.

4 Do the design inputs The origin of the input, or the source should be identified and lJ1'" D D have sufficient be readily retrievable within Exelon's documentation system.

rationale?

If not, then the source should be attached to the analysis. Ask yourself, would you provide more justification if you were performing this analysis? If yes, the rationale is likely incomplete.

j 5

Are design inputs The expectation is that an Exelon Engineer should be able to llf D D correct and reasonable clearly understand which input parameters are critical to the with critical parameters outcome of the analysis. That is, what is the impact of a identified, if change in the parameter to the results of the analysis? If the appropriate?

impact is larqe, then that parameter is critical.

/

6 Are design inputs Ensure the documentation for source and rationale for the

~ D ~

compatible with the inputs supports the way the plant is currently or will be SvffV( r way the plant is operated post change and they are not in conflict with any

-f-he. u J-t5 operated and with the design parameters.

licensinQ basis?

[..., ltf!-

ATTACHMENT 2 CC*AA-103-1003 Revision 9 Page 8of11 Owner's Acceptance Review Checklist for External Design Analyses Page 2 of 3 Design Analysis No.: _...;..A....._T""""tl;_-_.....O_...l-=0-9 _____ _ Rev:

/.+.

fA6e JB No 7

8 9

10 11 12 13 14 15 Question Are Engineering Judgments clearly documented and

ustified?

Are Engineering Judgments compatible with the way the plant is operated and with the licensing basis?

Do the results and conclusions satisfy the purpose and objective of the Desi n Anal sis?

Are the results and conclusions compatible with the way the plant is operated and with the licensin basis?

Have any limitations on the use of the results been identified and transmitted to the appropriate or anizations?

Have margin impacts been identified and documented appropriately for any negative impacts (Reference ER-AA-2007?

Does the Design Analysis include the applicable design basis documentation?

Have all affected design analyses been documented on the Affected Documents List (AOL) for the associated Conti uration Chan e?

Do the sources of inputs and analysis methodology used meet committed technical and regulatory re uirements?

Instructions and Guidance See Section 2.13 in CC-AA-309 for the attributes that are sufficient to justify Engineering Judgment. Ask yourself, would you provide more justification if you were performing this anal sis? If es, the rationale is like! incom lete.

Ensure the justification for the engineering judgment supports the way the plant is currently or will be operated post change and is not in conflict with any design parameters. If the Analysis purpose is to establish a new licensing basis, then this question can be answered yes, if the *ud ment su arts that new basis.

Why was the analysis being performed? Does the stated purpose match the expectation from Exelon on the proposed application of the results? If yes, then the analysis meets the needs of the contract.

Make sure that the results support the UFSAR defined system design and operating conditions, or they support a proposed change to those conditions. If the analysis supports a change, are all of the other changing documents included on the cover sheet as im acted documents?

Does the analysis support a temporary condition or 1 procedure change? Make sure that any other documents 1 needing to be updated are included and clearly delineated in the design analysis. Make sure that the cover sheet includes the other document where the re~ul~ of this] O anal sis rovide the in ut.

31 6 Ct Make sure that the impacts to margin are clearly shown within the body of the analysis. If the analysis results in reduced margins ensure that this has been appropriately dispositioned in the EC being used to issue the analysis.

Are there sufficient documents included to support the sources of input, and other reference material that is not readily retrievable in Exelon controlled Documents?

Determine if sufficient searches have been performed to identify any related analyses that need to be revised along with the base analysis. It may be necessary to perform some basic searches to validate this.

Compare any referenced codes and standards to the current design basis and ensure that any differences are reconciled.

If the input sources or analysis methodology are based on an out-of-date methodology or code, additional reconciliation may be required if the site has since committed to a more recent code Yes I No IN/A D

D DD D

ATTACHMENT 2 CC-AA-103-1003 Revision 9 Page 9 of 11 Owner's Acceptance Review Checklist for External Design Analyses Page 3 of 3 Design Analysis No.: ___ A=_...._:T,_D_--_0...... 10

____ 9:::;__ __ _

Rev: '-t f/+61::? IC No Question 16 Have vendor supporting technical documents and references (including GE DRFs) been reviewed when necessa ?

17 Do operational limits support assumptions and in uts?

Instructions and Guidance Based on the risk assessment performed during the pre-job brief for the analysis (per HU-AA-1212), ensure that sufficient reviews of any supporting documents not provided with the fi.nal analysis are ~erf~d*(J'/)\\ L

-.- I J I e) s.e.eI.Tff!_~esVl...l">

t7,t'9E>

<A1

)

J.-r: I I

Ensure the Tech Specs, Operating Procedures, etc. contain operational li!1]its tha!_SUP.port the analysis assumptions and in uts.

N c.ff't:: 1:..

Create an SFMS entry as required by CC-AA-4008. SFMS Number: 4 't966

ENERCON May 23, 2014 Mr. John Panici Exelon Nuclear Braidwood Nuclear Generating Station 35100 South Route 53 Braceville, IL 60407 Design Analysis ATD-0109 Revision 4 Page Id

Subject:

Independent Third Party Review for Braidwood Design Analysis "Thermal Performance of UHS During Postulated Loss of Coolant Accident" A TD-109, Revision 4, dated 16 May 2014

Dear Mr. Panici,

ENERCON has reviewed the subject design analysis revision under the requirements for third party review given by HU-AA-1212.

Due to the fact that the calculation used S&L computer program(s) to which ENERCON did not have access, this review is limited to an assessment of the overall approach and methodology along with the reasonableness of the inputs, assumptions, and conclusions.

The purpose and background of the calculation are found to be consistent with the requirements of the project. However, while section 1.0 states that the purpose of the calculation is to demonstrate the adequacy of the Ultimate Heat Sink (UHS) to provide sufficient cooling under the worst case environmental conditions, the determination of adequacy is not clearly demonstrated. This is considered to be a weakness.

The assumed water properties are judged to be acceptable as is the assumption of no makeup to the ultimate heat sink (UHS) from other sources.

The overall approach is found to be reasonable; the methodology section indicates that the approach follows the recommendations of Regulatory Guide 1.27. However, while RG 1.27 includes acceptability criteria for the UHS, the calculation draws no conclusions as to the acceptability of the results of the analyses.

Additional observations detailed within the attached comment/resolution form.

4 Campus Drive Suite JOO

May 23, 2014 Mr. John Panici Page 2of5 Please call if you have any questions or comments or wish to discuss.

Sincerely J. P. Logatto Lead Mechanical Engineer ENERCON Northeast Cc: R. Klacik (Enercon) 4 Compm DrfH1 NJ 07()54 Design Analysis ATD-0109 Revision 4 Page le

May 23, 2014 Mr. John Panici Page 3of5 Attachment l Comment I Resolution Form Design Analysis ATD-0109 Revision 4 Page 1f No.

Comment Resolution Concur (YIN)

Purpose section was clarified as follows:

ATD-0109, 1.0: Section states The purpose of this calculation is to 1

that the purpose is to demonstrate determine the thermal response of the Y/JPL the adequacy of the Ultimate Heat Ultimate Heat Sink (UHS) during the Sink (UHS) under the worst case shutdown of both units after a Design environmental conditions. This Basis Accident (DBA) under worst case objective is not met.

environmental conditions.

ATD-0109, PIO: Basis for design Reference for the drawdown curve input 4.2 not clear. The (Section 4.2) is changed to Ref. 5.4 2

referenced calculation, MAD 83-which is a Area/Volume vs. Elevation Y/JPL 0239, does not clearly establish plot. This plot is a part of calculation the basis for the drawdown of the MAD 83-0239.

UHS.

ATD-0109: Section 6.0 does not Section 6 only contains calculations adequately describe the that are not documented in other parts computations being performed, (Attachments) of the calculation. To with the exception of avoid duplication it is proposed that 3

determination of a transit time this section remains as is.

Y/JPL calculated for the normal UHS level in subsection 6.2. For this reason, proper use of the design inputs cannot be fully assessed.

A TD-0109, Table 6-2: The design This has been changed as follows inputs are from section 4.0; the 2.1 changed to 4.2 4

Design Basis column calls out 2.3 changed to 4.5 Y/JPL design input numbers 2.1 & 2.3 for effective volume and flowrate, respectively.

ATD-0109: Section 7.0 presents Per discussion with Exelon the results in the form of maximum acceptability of the UHS temperatures plant inlet temperature, but draws will be performed in follow-on 5

no conclusions as to the analysis. This calculation will only Y/JPL acceptability of the resulting calculate thermal response. Purpose has temperatures or the effect on plant been adjusted per comment # I.

cooldown.

Attachment A, P A5: What is the This flow rate is selected to create a 6

source of the circulating water transit time of 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months through the lake.

Y/JPL flow of 1844.8 ft3/s? Provide

May 23, 2014 Mr. John Panici Page 4of5 7

8 reference.

Attachment A, PA5, 2.2: What is the basis for the temperature rise values given by the 5th bullet?

Conflicts with temperature rise values iven in Attachment C.

Attachment A, PA12, Table 6-7:

How is the lake temperature a function of the number of pumps running? There should be a discussion of the results and an explanation of their significance.

Design Analysis ATD-0109 Revision 4 Page lg This bullet point in Section 2. I of Attachment A has been updated to clarify this calculation as follows:

The plant flow is set at 1844.8 fr Is to a lake transit time of 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months r Plant Flow = Effective Time. 457.4 iacre-jt / 10. 800 s ******

The basis for the temperature rise values given by the 5th bullet is provided in the second paragraph of Assumption 3.3 of Attachment A. This is an average of the temperature rise values rovided in Attachment C.

The worst weather file changes based on the number of pumps in operation.

Since the weather starts on different dates, the initial natural lake temperature will change based on the case being run.

These temperatures are used as input in the main body of this calculation.

Further explanation has been added to this paragraph as follows:

The initial natural temperature for each case is taken to be the natural temperature of the lake at the time step of the start date of the weather file.

The natural lake temperature at these time steps is found in the results of the

'Worst_ Weather_ 110' case from the file 'Worst_ Weather_ 11 O.pltX'.

natural he used 10 set natural lake temperature in worst weather LAKET runs in the main bodv calculation.

The initial natural temperatures are summarized in the table below.

01054 fax 971.60UJ5!5 Y/JPL Y/JPL

May 23, 2014 Mr. John Panici Page 5of5 4

973.601.0510 Design Analysis ATD-0109 Revision 4 Page lb

ATD-0109, Rev. 4 Page 2of19 CALCULATION TABLE OF CONTENTS SECTION:

PAGE NO.

SUB-PAGE NO.

COVER PAGE 1

OWNER'S ACCEPTANCE REVIEW CHECKLIST 1A-'~

1.H TABLE OF CONTENTS 2

Gf 6--Z..-ZIJ I~

1.0 PURPOSE AND BACKGROUND 3

2.0 METHODOLOGY AND ACCEPTANCE CRITERIA 4

3.0 ASSUMPTIONS 9

4.0 DESIGN INPUTS 10

5.0 REFERENCES

11 6.0 CALCULATIONS 13 7.0 RESULTS AND CONCLUSIONS 16 ATTACHMENT A-LAKET-PC Weather File Creation A1-A16 ATTACHMENT B-Update Hourly Meteorological Data 81-847 Used for Cooling Lake Analysis ATTACHMENT C-Plant Temperature Rise C1-C4 ATTACHMENT D - MES-11.1 Stratification Review 01-04 ATTACHMENT E-LAKET-PC Output Plots E1-E33 ATTACHMENT F - Electronic Files List F1-F3

ATD-0109, Rev. 4 Page 3 of 19 1.0 PURPOSE AND BACKGROUND 1.1 Purpose The purpose of this calculation is to determine the thermal response of the Ultimate Heat Sink (UHS) during the shutdown of both units after a Design Basis Accident (DBA) under worst case environmental conditions. One unit is postulated to have a loss of coolant accident (LOCA), with loss of off site power (LOOP), and the other unit is postulated to undergo normal shutdown. The main dam of the lake is also assumed to have been breached due to a seismic event making use of the Ultimate Heat Sink (which is a Category I structure) necessary.

Revision 4 The purpose of Revision 4 is to revise the existing Ultimate Heat Sink (UHS) analysis to increase the initial UHS temperature to 102°F. The revision also includes updated meteorological conditions from 7/5/1948 up to 12/31/2012 (using weather data from Peoria, IL and onsite meteorological data) as well as the weather selection methodology from Rev. 2 of Regulatory Guide 1.27 [Ref.

5.6]. This revision includes updates to the latest revision of UHS Heat Load Analysis [Ref. 5.2] with the post-MUR power level for 2, 3, and 4 Essential Service Water (SX) pumps in operation.

Following are the specific changes included in Revision 4:

o Initial UHS temperature increased to 102°F o Updated weather (1948 to 2012), worst weather selection per Rev 2 of the Regulatory Guide 1.27 o UHS Heat Load updated per latest revision of the heat load calculation ATD-0063.

o Case runs (8 per day, every 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months starting at 12 AM) with 2, 3, and 4 SX pumps in operation plus 3 maximum evaporation cases, and 2 sensitivity cases.

The analysis determines following parameters:

o Maximum UHS temperature v.s. DBA start time o Maximum UHS inventory loss

1.2 Background

The thermal performance of the Braidwood UHS was originally developed based on the initial UHS temperature of 98°F and hot weather condition from summer of 1955 for highest UHS temperature and summer of 1971 for highest UHS evaporation. Over the years the UHS analysis was revised to increase the initial UHS temperature to 100°F. This revision increases the initial UHS temperature to 102°F, updates to the latest meteorological conditions up to 12/31/2012, and latest revision of UHS Heat Load Analysis.

ATD-0109, Rev. 4 Page 4 of 19 2.0 METHODOLOGY AND ACCEPTANCE CRITERIA The Sargent & Lundy (S&L) LAKET-PC computer program [Ref. 5.5] is utilized to determine the combined impact of plant heat load (both Units), SX flowrate, initial UHS temperature, and meteorological conditions on the UHS response. Based on the initial UHS temperature of 102°F and the worst meteorological conditions, the maximum UHS temperature is determined for 8 different start times (every 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months , starting at 12 AM) with 2, 3, and 4 SX pumps in operation. Additionally the worst evaporation (highest inventory loss) over the 30 days is determined.

LAKET-PC computer program [Ref. 5.5] is a one-dimensional thermal prediction model based on the plug flow model as described in the NUREG-0693 [Ref.

5.13]. Additional justification of applicability of LAKET-PC to Braidwood UHS is discussed in Attachment D.

2.1 Methodology 2.1.1 Regulatory Guide Criteria Reg. Guide 1.27, Rev. 2 [Ref. 5.6] describes a method for considering meteorological conditions in the design of the UHS. A synthetic weather file is created using weather data from the critical time period (which depends on the total SX flow rate) due to design of the UHS, the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and the worst 30 days, combined in this order. For the Braidwood UHS, the critical time period unique to the design of the UHS is the transit time, which depends on the number of SX pumps in operation. The transit time is 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months for two SX pumps in operation, 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months for three SX pumps in operation, and 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for four SX pumps in operation (see Section 6.2).

2.1.2 Selection of Worst Weather and Worst Net Evaporation Data The methodology used to determine the worst 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , 36 hour4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months and 30 day temperature periods is documented in Attachment A. The weather data considered in this analysis spans from July 1948 to December 2012 using weather data from Peoria, IL and Springfield, IL from July 1948 to December 1997 and from Braidwood Nuclear Generating Station and Peoria, IL from January 1998 to December 2012. This is described in more detail in Attachment A. Since cases will be run at varying start times, the worst weather for each of the time periods listed above will be found at each different starting time.

In addition to finding the worst weather time periods, the 30 day period resulting in the worst net evaporation is also determined. This is done following a similar methodology to finding the worst weather and is documented in Attachment A.

ATD-0109, Rev. 4 Page 5 of 19 2.1.3 Plant Temperature Rise The plant temperature rise (which is an input to the LAKET-PC model) is dependent on the heat load that is rejected to the UHS. The rejected heat load is determined in ATD-0063 [Ref. 5.2].

The temperature rise through the plant is determined by the following equation:

m c

Q T

p

(Eq. 2-1) where:

T

= plant temperature rise [°F]

Q

= heat rejection rate to the UHS [BTU/hr]

cp

= specific heat capacity of water [BTU/(lbm-°F)]

m

= mass flow rate [lbm/hr], [Ref's. 5.11 and 5.12]

3 3

3 1728 4.

62 60 231 ft in hr m

gal in GPM m

(Eq. 2-2) where:

GPM

= plant flow [gpm]

62.4

= water density [lb/ft3, Assumption 3.1]

The LAKET-PC runs for Braidwood UHS are performed based on the 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months time steps. Therefore the plant temperature rise (T ) needs to be calculated for every time step. Since the heat rejection rate is decreasing rapidly during the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months [Ref. 5.2] the total heat rejected in any given time step in the first 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is calculated by the trapezoidal rule integration as shown by the equation below:

3 60 60 2

1 1

i i

step time Q

Q t

t Q

(Eq. 2-3) where:

Qtime_step

= average heat rejection rate over the 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months time step [BTU/hr]

t

= time [sec]

Q

= heat rejection rate to the UHS [BTU/hr]

For the time steps after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and up to 222 hours0.00257 days 0.0617 hours 3.670635e-4 weeks 8.4471e-5 months , the heat rejection rate is linearly interpolated based on the available data. The heat rejection rate above the 222 hours0.00257 days 0.0617 hours 3.670635e-4 weeks 8.4471e-5 months is conservatively held as a constant value based on the last

ATD-0109, Rev. 4 Page 6 of 19 available point from the UHS heat load calculation [Ref. 5.2]. The results of these calculations and the values entered into the LAKET-PC model are presented in Attachment C.

2.1.4 Wind Gradients LAKET-PC models wind gradients (as a function of the elevation above ground level) per the following equation:

3.0) 56

.6

(

15

.1 WINDZ knots mph WNDCOR

(Eq. 2-4) where:

WNDCOR = wind correction factor to 2m above ground level WINDZ

= measurement elevation above ground level [ft]

1.15

= conversion factor from knots to mph The wind speed extrapolation is a power law equation correcting the wind speed to an elevation of 2 meters (6.56 ft) above the ground level (the reference wind speed elevation used for wind functions in MIT Report No. 161 [Ref. 5.14]).

There are a variety of exponential factors that have been used over the years in the power law equation, LAKET-PC uses a conservatively bounding value of 0.3 for the exponent.

2.1.5 LAKET-PC Case Runs There are two different types of cases that are run in LAKET-PC: 1) Worst temperature cases and 2) Worst net evaporation cases.

A) Worst Temperature Cases - The worst temperature cases determine the maximum UHS outlet temperature based on an initial UHS temperature of 102°F.

These cases are run at 8 varying start times throughout the day (every 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months , starting at 12 AM). Additionally, a limiting 4 SX pump case is rerun to determine the maximum UHS initial temperature that would result in maximum UHS temperature of 104°F. As a sensitivity case, a limiting 3 SX pump case is rerun with a reduced UHS inventory corresponding to 3" of sedimentation.

B) Worst Net Evaporation Cases - The net evaporation cases use the same input file as the corresponding worst weather case (2, 3, or 4 SX pumps), but are run with the most limiting 30-day net evaporation weather file. These cases are run with two, three, and four SX pumps in operation. The most limiting net evaporation weather is 6/1/1988 to 7/1/1988 (9 AM start) as determined in Attachment A.

ATD-0109, Rev. 4 Page 7 of 19 A summary of all cases run for this analysis is shown below:

Table 2-1: List of LAKET-PC Cases Case Name Time Period SX Pumps Start Time Weather File Worst Temperature Cases - 2 SX Pumps Case 2_12AM worst 48 hrs + worst 24 hrs + worst 30 days 2

0:00 12AM_2.txt Case 2_3AM worst 48 hrs + worst 24 hrs + worst 30 days 2

3:00 3AM_2.txt Case 2_6AM worst 48 hrs + worst 24 hrs + worst 30 days 2

6:00 6AM_2.txt Case 2_9AM worst 48 hrs + worst 24 hrs + worst 30 days 2

9:00 9AM_2.txt Case 2_12PM worst 48 hrs + worst 24 hrs + worst 30 days 2

12:00 12PM_2.txt Case 2_3PM worst 48 hrs + worst 24 hrs + worst 30 days 2

15:00 3PM_2.txt Case 2_6PM worst 48 hrs + worst 24 hrs + worst 30 days 2

18:00 6PM_2.txt Case 2_9PM worst 48 hrs + worst 24 hrs + worst 30 days 2

21:00 9PM_2.txt Worst Temperature Cases - 3 SX Pumps Case 3_12AM worst 36 hrs + worst 24 hrs + worst 30 days 3

0:00 12AM_3.txt Case 3_3AM worst 36 hrs + worst 24 hrs + worst 30 days 3

3:00 3AM_3.txt Case 3_6AM worst 36 hrs + worst 24 hrs + worst 30 days 3

6:00 6AM_3.txt Case 3_9AM worst 36 hrs + worst 24 hrs + worst 30 days 3

9:00 9AM_3.txt Case 3_12PM worst 36 hrs + worst 24 hrs + worst 30 days 3

12:00 12PM_3.txt Case 3_3PM worst 36 hrs + worst 24 hrs + worst 30 days 3

15:00 3PM_3.txt Case 3_6PM worst 36 hrs + worst 24 hrs + worst 30 days 3

18:00 6PM_3.txt Case 3_9PM worst 36 hrs + worst 24 hrs + worst 30 days 3

21:00 9PM_3.txt Worst Temperature Cases - 4 SX Pumps Case 4_12AM worst 24 hrs + worst 24 hrs + worst 30 days 4

0:00 12AM_4.txt Case 4_3AM worst 24 hrs + worst 24 hrs + worst 30 days 4

3:00 3AM_4.txt Case 4_6AM worst 24 hrs + worst 24 hrs + worst 30 days 4

6:00 6AM_4.txt Case 4_9AM worst 24 hrs + worst 24 hrs + worst 30 days 4

9:00 9AM_4.txt Case 4_12PM worst 24 hrs + worst 24 hrs + worst 30 days 4

12:00 12PM_4.txt Case 4_3PM worst 24 hrs + worst 24 hrs + worst 30 days 4

15:00 3PM_4.txt Case 4_6PM worst 24 hrs + worst 24 hrs + worst 30 days 4

18:00 6PM_4.txt Case 4_9PM worst 24 hrs + worst 24 hrs + worst 30 days 4

21:00 9PM_4.txt Worst Net Evaporation Cases Case 2_evap worst 30 days for evaporation 2

9:00 Net_Evap.txt Case 3_evap worst 30 days for evaporation 3

9:00 Net_Evap.txt Case 4_evap worst 30 days for evaporation 4

9:00 Net_Evap.txt 2.2 Acceptance Criteria There are no specific acceptance criteria in this analysis. The maximum calculated UHS temperature and minimum UHS water level are to be used as input to the follow-on analysis.

ATD-0109, Rev. 4 Page 8 of 19 2.3 Identification of Computer Programs Post processing of the LAKET-PC results is done using Microsoft Excel 2003

[Ref. 5. 7], which is commercially available. The validation of Excel is implicit in the detailed review of all spreadsheets used in this analysis. All computer runs were performed using PC No. ZL7923 under the Windows XP operating system.

LAKET-PC Version 2.3 [Ref. 5.5] was used to perform the lake transient analysis contained in this evaluation. This was run on S&L PC No. ZL7923 on the Windows XP operating system. Note that LAKET-PC computer code was also utilized in support of LaSalle UHS License Amendment Request.

ATD-0109, Rev. 4 Page 9 of 19 3.0 ASSUMPTIONS 3.1 Water Properties - The density and specific heat of water in the UHS is assumed to be 62.4 lb/ft3 and 1 Btu/lb-°F, respectively [Ref. 5.12]. The density varies from 62.4 lb/ft3 at 60°F to 61.9 lb/ft3 at 105°F which correspond to ~0.7% change. The specific heat varies from 1 Btu/lb-°F at 60°F to 0.998 Btu/lb-°F at 105°F which correspond to ~0.2% change. These changes are acceptable since they are very small and have negligible impact on the results of analysis.

3.2 Makeup, Blowdown, Runoff, etc. - It is assumed that there is no makeup, blowdown, runoff, or dam spill in the UHS.

ATD-0109, Rev. 4 Page 10 of 19 4.0 DESIGN INPUTS 4.1 Seepage Rate - The seepage rate is 0.8 ft3/s [Ref. 5.3].

4.2 Area Capacity Data - The normal UHS elevation is 590 ft and is used as the initial UHS elevation. The drawdown curve for the UHS is given in the table below [Ref. 5.4].

Table 4-1: UHS Drawdown Curve Elevation (ft)

Gross Area (acres)

Gross Volume (acre-ft)

Effective Area*

(acres)

Effective Volume*

(acre-ft) 590.0 95.6 555.8 78.7 457.4 589.0 94.5 460.0 77.8 378.6 588.0 93.5 370.0 77.0 304.5 587.0 92.5 276.0 76.1 227.1 586.0 91.5 185.0 75.3 152.3 585.0 90.5 90.0 74.5 74.1

Effective Area and Volume are 82.3% of Gross values per Design Input 4.4.

Note that for the sensitivity case (limiting 3 SX pump case) with 3" of sedimentation a gross UHS volume is reduced by 3/12*90=22.5 (acre-ft).

4.3 UHS Length - The total length of the UHS is 3076 ft [Ref. 5.1].

4.4 UHS Effectiveness - Effectiveness of the UHS pond is 82.3% as determined in Calculation MAD 83-0239 [Ref. 5.1].

4.5 SX Flow - The SX flow for operation with 3 pumps is taken is 64,000 gpm. This is conservatively higher than the calculated flow for 3 SX pumps as documented in the hydraulic calculation [Ref. 5.8].

For operation with 2 and 4 pumps, the SX flow is taken as 48,000 gpm and 96,000 gpm respectively. This flow rate is estimated from the rated flow capacity per pump (24,000 gpm) and the number of pumps [Refs. 5.9 and 5.10]. The value is greater than the flow that actually will occur because the pressure drop caused by the resistance of the system is larger than the design value and causes the pump to run back on its performance curve as shown in the hydraulic calculation [Ref. 5.8]. The use of an estimated flow which is greater than the actual value yields a conservative UHS temperature prediction. This is illustrated by the results in Section 7.1 which show an increased plant intake temperature with an increase of SX flow.

4.6 Heat Load to the UHS - The post-MUR heat load rejected to the UHS is taken from ATD-0063, page E9, Table 13 [Ref. 5.2].

4.7 Wind Sensor Elevation - The elevation of the wind sensor is 34 ft for maximum temperature cases and 20 ft for the maximum evaporation cases based on Attachment B. Note, that the wind speed is corrected to an elevation of 2 meters as specified in Section 2.1.4.

ATD-0109, Rev. 4 Page 11 of 19

5.0 REFERENCES

Note: Revision level check was performed for References 5.1, 5.2, 5.4, 5.8, 5.9, 5.10, and 5.15 via the PASSPORT database on 5/14/2014.

5.1 Ultimate Heat Sink Update, Calculation MAD 83-0239, Rev. 1. 9-3-1985 5.2 Heat Load to the Ultimate Heat Sink During a Loss of Coolant Accident, Calculation ATD-0063, Rev. 5, 11-27-2012.

5.3 DIT No. BR-0234-0004, D.G. Bodine to S. Masini, 8-29-85. (Documented as part of MAD 83-0239 [Ref. 5.1]

5.4 Revised Area Capacity Curve for Ultimate Heat Sink. (Documented as part of MAD 83-0239 [Ref. 5.1]

5.5 LAKET-PC Computer Prog., Version 2.3, S&L Program No.03.7.292-2.3, with the following controlled files:

5.6 U.S. Atomic Energy Commission, Regulatory Guide 1.27, Rev. 2, January 1976, Ultimate Heat Sink for Nuclear Power Plants, 5.7 Microsoft Excel 2003, SP 2, Sargent & Lundy LLC Program No. 03.2.434-1.0, dated 05/21/2007.

5.8 Hydraulic Calculation # BRW-99-0481-M, Rev 001E, "Essential Service Water System Flow Model".

5.9 Byron SX Pump Curve Drawing # 76071, Rev A, "1SX01PA Pump Curve" 5.10 SX Pump Drawing # B-33842X, Rev 0, " Bingham-Willamette Co. Spec No L2758A.

5.11 Crane Technical Paper No. 410, Flow of Fluids through Valves, Fittings, and Pipe, 1988.

5.12 "ASME Steam Tables, Thermodynamic and Transport Properties of Steam",

1967.

5.13 NUREG-0693, Analysis of Ultimate Heat Sink Cooling Ponds, Office of Nuclear Reactor Regulation, Nuclear Regulatory Commission, November 1980.

5.14 MIT Report 161, An Analytical and Experimental Study of Transient Cooling Pond Behavior, Ryan and Harleman, Massachusetts Institute of Technology, Cambridge Massachusetts, 1973.

ATD-0109, Rev. 4 Page 12 of 19 5.15 P&ID M-42, Sheet 6, Rev T, "Diagram of Essential Service Water".

5.16 Avallone, Eugene A. and Baumeister III, Theodore, Marks Standard Handbook for Mechanical Engineers, 10th edition.

ATD-0109, Rev. 4 Page 13 of 19 6.0 CALCULATIONS 6.1 Plant Temperature Rise The plant mass flow rate used in calculation of the plant temperature rise is calculated based on equation 2-2 and presented in the Table 6-1.

Table 6-1: Plant Flow Number of SX Pumps Plant Volumetric Flow (gpm)

Plant Volumetric Flow (cfs)

Plant Mass Flow (lbm/hr) 2 48,000 106.94 24,025,000 3

64,000 142.59 32,030,000 4

96,000 213.89 48,050,000 Plant temperature rise for all cases is calculated based on the methodology from Section 2.1.3. The results of these calculations and the values entered into the LAKET-PC model are presented in Attachment C.

6.2 UHS Transit Time The UHS transit time differs depending on the number of SX pumps in operation.

The transit time is determined using the effective volume and UHS flow rate.

This calculation is shown in Table 6-2.

Table 6-2: Transit Time Calculation Symbol 2 Pumps 3 Pumps 4 Pumps Basis Eff. Volume @ 590 ft (acre-ft)

Ve 457.4 457.4 457.4 Design Input 4.2 Conversion (ft3/acre-ft)

C1 43560 43560 43560 Volume (ft3)

V 19,924,344 19,924,344 19,924,344 = Ve

C1 Flow Rate (gpm)

Qgpm 48,000 64,000 96,000 Design Input 4.5 Conversion (ft3/s / gpm)

C2 0.002228 0.002228 0.002228

= (0.13368 gal/ft3) / (60 s/min)

Flow Rate (ft3/s)

Q 106.94 142.59 213.89

= Qgpm

C2 Total Transit Time (s) t 186,306 139,730 93,153

= V / Q Total Transit Time (hr) t 51.8 38.8 25.9

= t / (3600 s/hr)

ATD-0109, Rev. 4 Page 14 of 19 The weather files are screened in 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months time periods. To account for reduced transit time as the UHS loses volume due to evaporation and to match the LAKET-PC 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months time step, the total transit time is conservatively rounded down. This makes the UHS transit time 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months for two pumps in operation, 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months for three pumps in operation, and 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for four pumps in operation.

6.3 Worst Weather Selection Selection of the worst weather is done in Attachment A. The worst weather is found for three different time periods: 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months , and 30 days.

Since cases are run at different start times, the worst weather is found for every analyzed start time. These results are summarized in the table below.

Table 6-3: Worst 30-Day Weather Results Start Time Worst 30-day Start Date 12AM 7/10/2011 3AM 7/9/2011 6AM 7/9/2011 9AM 7/9/2011 12PM 7/9/2011 3PM 7/9/2011 6PM 7/9/2011 9PM 7/9/2011 Table 6-4: Worst 24-hr, 36-hr, and 48-hr Weather Results Start Time Worst 24-hr Start Date Worst 36-hr Start Date Worst 48-hr Start Date 12AM 6/23/2009 7/6/2012 7/5/2012 3AM 6/23/2009 7/6/2012 7/5/2012 6AM 7/19/2011 7/6/2012 7/5/2012 9AM 7/6/2012 6/22/2009 6/22/2009 12PM 7/6/2012 6/22/2009 7/5/2012 3PM 7/6/2012 6/22/2009 7/5/2012 6PM 7/6/2012 7/5/2012 7/5/2012 9PM 7/26/1999 7/5/2012 7/5/2012 In addition, the 30 days leading to the worst net evaporation is determined in Attachment A. For all SX pump operating conditions the worst 30 day period was determined to start on June 1, 1988 at 9:00 AM.

Synthetic weather files are created from these worst weather and worst net evaporation time periods. Documentation of the creation of these weather files is provided in Attachment A.

ATD-0109, Rev. 4 Page 15 of 19 6.4 Natural Lake Temperatures LAKET-PC uses natural lake temperature as one of the inputs. The natural lake temperature is determined and documented in Attachment A, Table 6-7. The natural lake temperature is used as initial condition to set up the initial temperature of the non participating part of UHS. The non participating part of UHS is defined as the part of the UHS that does not see the plant heat load. In case of Braidwood UHS this constitutes 17.7% of the UHS (since the UHS effectiveness is 82.3%, see Design Input 4.4).

6.5 Wind Function Selection In accordance with NUREG-0693 [Ref. 5.13] recommendation, Ryan and Harleman wind function is selected in LAKET-PC modeling for all cases.

6.6 Maximum UHS Temperature LAKET-PC is run to determine the UHS response to the plant heat load under the worst environmental conditions. Cases are run with 2, 3, and 4 SX pumps in operation. The time of day which the accident occurs is critical when determining the maximum allowable initial temperature of the UHS. To account for the time of day at which the UHS transient may start, eight start times are used for each alignment of SX pumps. These cases are run using the synthetic weather files consisting of the worst weather periods developed in Attachment A. Results from the LAKET-PC runs are presented in Section 7.1.

6.7 Maximum Net Evaporation Case 2_Evap, Case 3_Evap, and Case 4_Evap were run to determine the maximum expected UHS drawdown depending on the SX pump alignment.

These cases are run using the worst 30-day net evaporation weather period, which was determined to be 6/1/88 to 7/1/88 (9:00 AM start) in Attachment A.

The results of these cases are presented in Section 7.2.

6.8 3" of Sedimentation Sensitivity Case As an additional case a limiting 3 SX pump case with 3" of sedimentation is run.

For this run a gross UHS volume is reduced by 3/12*90=22.5 (acre-ft) which corresponds to the bottom 3" of the UHS. For this case the area capacity data from Design Input 4.2 is modified as follows:

Table 6-5: UHS Drawdown Curve - 3" Sedimentation Elevation (ft)

Gross Area (acres)

Gross Volume (acre-ft)

Effective Area*

(acres)

Effective Volume*

(acre-ft) 590.0 95.6 533.3 78.7 438.9 589.0 94.5 437.5 77.8 360.1 588.0 93.5 347.5 77.0 286.0 587.0 92.5 253.5 76.1 208.6 586.0 91.5 162.5 75.3 133.7 585.0 90.5 67.5 74.5 55.6

Effective Area and Volume are 82.3% of Gross values per Design Input 4.4.

ATD-0109, Rev. 4 Page 16 of 19 7.0 RESULTS AND CONCLUSIONS 7.1 Maximum UHS Temperature LAKET-PC was run to determine the maximum UHS temperature following an accident. All cases are run at an initial UHS temperature of 102°F. The results of these LAKET-PC runs are provided in Table 7-1 for 2 SX pumps in operation, in Table 7-2 for 3 SX pumps in operation, and in Table 7-3 for 4 SX pumps in operation.

Table 7-1: Worst Temperature Cases - 2 SX Pumps (48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months transit time)

Case Weather Data SX Pumps Initial UHS Temp. (°F)

Maximum Plant Inlet Temp. (°F)

Case 2_12AM 12AM_2.txt 2

102.0 102.0 Case 2_3AM 3AM_2.txt 2

102.0 102.5 Case 2_6AM 6AM_2.txt 2

102.0 103.7 Case 2_9AM 9AM_2.txt 2

102.0 103.6 Case 2_12PM 12PM_2.txt 2

102.0 103.1 Case 2_3PM 3PM_2.txt 2

102.0 102.2 Case 2_6PM 6PM_2.txt 2

102.0 102.0 Case 2_9PM 9PM_2.txt 2

102.0 102.0 Table 7-2: Worst Temperature Cases - 3 SX Pumps (36 hour4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months transit time)

Case Weather Data SX Pumps Initial UHS Temp. (°F)

Maximum Plant Inlet Temp. (°F)

Case 3_12AM 12AM_3.txt 3

102.0 104.5 Case 3_3AM 3AM_3.txt 3

102.0 105.2 Case 3_6AM 6AM_3.txt 3

102.0 104.4 Case 3_9AM 9AM_3.txt 3

102.0 103.6 Case 3_12PM 12PM_3.txt 3

102.0 103.3 Case 3_3PM 3PM_3.txt 3

102.0 104.0 Case 3_6PM 6PM_3.txt 3

102.0 104.7 Case 3_9PM 9PM_3.txt 3

102.0 103.4 Case 3_3AM_3" 3AM_3.txt 3

102.0 105.0

ATD-0109, Rev. 4 Page 17 of 19 Note that the peak UHS temperatures for 3 SX pumps in operation cases occur

~39 hours after the DBA and it exceeds 104°F for less than 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months . This is shown in detail on the UHS temperature plot Figure 7-1.

Figure 7-1: Limiting 3 SX Pump Case - 3AM Start Maximum UHS Temperature - 3 SX Pumps - 3AM Start 92 94 96 98 100 102 104 106 0

3 6

9 12 15 18 21 24 27 30 33 36 39 42 45 48 Hours Following Accident Plant Inlet Temp (°F)

As seen on Figure 7-1 the UHS initially starts at 102°F. Since the accident begins at 3 AM the UHS temperature initially decreases as a result of cool environmental conditions during early morning hours. The UHS temperature then increases due to solar heat and hot environmental conditions throughout the day. Starting in the late afternoon and continuing throughout the night the UHS temperatures drops displaying a typical diurnal cycle. Beginning with ~36 hours after the DBA the plant heat comes back to the plant inlet peaking ~39 hours after the DBA. This is shown on Figure 7-1 as a sharp increase in the UHS temperature from ~102°F to ~105.2°F. The peak temperature excursion is short lived and it exceeds 104°F for less than 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

The 3AM Case with 3" of sedimentation (see Figure 7-2) demonstrates that the small changes to the UHS volume have negligible affects on the maximum UHS temperature.

ATD-0109, Rev. 4 Page 18 of 19 Figure 7-2: Limiting 3 SX Pump Case - 3AM Start - 3" of Sediment Maximum UHS Temperature - 3 SX Pumps - 3AM Start 96 97 98 99 100 101 102 103 104 105 106 0

3 6

9 12 15 18 21 24 27 30 33 36 39 42 45 48 Hours Following Accident Plant Inlet Temp (°F) 3AM 3AM-3" Sediment In the case with 3" of sedimentation, the volume at the bottom of the UHS is slightly reduced. The reduction is small enough that the model is still in a 36 hour4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months transient time, however with the smaller volume the cooling of the UHS has a slightly larger effect. Therefore, the peak temperature after 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months is slightly lower (~0.2°F). However, looking at the first day peak, the temperature with 3" of sedimentation is slightly higher (~0.03°F), since it is easier to heat up the smaller volume. For the other start times the peak temperature may slightly increase with a slight reduction of volume (if the peak occurs on the first day). Overall, it is concluded that with small changes in UHS volume, the peak temperature change is negligible.

ATD-0109, Rev. 4 Page 19 of 19 Table 7-3: Worst Temperature Cases - 4 SX Pumps (24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months transit time)

Case Weather Data SX Pumps Initial UHS Temp. (°F)

Maximum Plant Inlet Temp. (°F)

Case 4_12AM 12AM_4.txt 4

102.0 103.2 Case 4_3AM 3AM_4.txt 4

102.0 104.0 Case 4_6AM 6AM_4.txt 4

102.0 105.9 Case 4_9AM 9AM_4.txt 4

102.0 105.4 Case 4_12PM 12PM_4.txt 4

102.0 104.7 Case 4_3PM 3PM_4.txt 4

102.0 105.0 Case 4_6PM 6PM_4.txt 4

102.0 104.5 Case 4_9PM 9PM_4.txt 4

102.0 103.6 Case 4_6AM104 6AM_4.txt 4

96.4 104 As shown in the above tables the cases with 4 SX operating pumps results in the highest UHS temperatures. For the limiting 4 SX pump scenario (6AM start) an additional case is made to determine the maximum UHS initial temperature that results in maximum UHS temperature of 104°F. Plots of UHS temperatures for all cases are presented in Attachment E.

7.2 Maximum Net Evaporation Three LAKET-PC cases were run to determine the maximum expected drawdown for 2, 3, and 4 SX pumps in operation. The results of these cases are provided in Table 7-4.

Table 7-4: Worst Temperature Cases Case Weather Data SX Pumps Initial UHS Temp. (°F)

Maximum UHS Drawdown (ft)

Case 2_Evap NetEvap.txt 2

102 1.76 Case 3_Evap NetEvap.txt 3

102 1.77 Case 4_Evap NetEvap.txt 4

102 1.78 The maximum 30 day drawdown from the initial UHS elevation 590 ft occurs with 4 SX pump in operation. The minimum UHS elevation after the worst 30 day period is ~588.2 ft (1.78 ft reduction). Plots of UHS elevation for all three cases are presented in Attachment E.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A1 of A16 Attachment A LAKET-PC Weather File Creation Prepared:

Date Daniel W. Nevill - Sargent & LundyLLC Reviewed:

Date Paul J. Szymiczek - Sargent & LundyLLC

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A2 of A16 TABLE OF CONTENTS Section Page No.

1.0 Purpose / Objective.......................................................................................................3 2.0 Methodology...................................................................................................................4 3.0 Assumptions....................................................................................................................7 4.0 Design Inputs...................................................................................................................8 5.0 References.......................................................................................................................9 6.0 Calculations and Results...............................................................................................10 7.0 Summary and Conclusions............................................................................................13 8.0 Appendices....................................................................................................................14 (Total Pages - Main Body (14) plus Appendices (2) for a Total of 16 pages)

LIST OF TABLES Table No.

Title Page 6-1 Worst 30-Day Weather Results 10 6-2 Worst 24-hr, 36-hr, and 48-hr Weather Results 10 6-3 2 Pump Operation Weather Files 11 6-4 3 Pump Operation Weather Files 11 6-5 4 Pump Operation Weather Files 12 6-6 Worst Net Evaporation Weather Files 12 6-7 Natural Lake Temperature 12 LIST OF APPENDICES No.

Title Page 8.1 Electronic File Listing 15 (Total Appendix Pages - 2)

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A3 of A16 1.0 PURPOSE / OBJECTIVE The purpose of this attachment is to determine the worst 24-hour, 36-hour, 48-hour and 30-day weather period and the worst 30-day period of net evaporation for Braidwood Nuclear Generating Station. This will be used as input in determining the maximum plant inlet temperature and evaporative drawdown of the Braidwood Ultimate Heat Sink (UHS), which determines the design basis UHS performance for 30 days following an accident. Weather data has been provided from July 5, 1948 through December 31, 2012.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A4 of A16 2.0 METHODOLOGY A LAKET-PC-compatible meteorological data file, PIABDW4812.txt, was created consisting of meteorological data for Braidwood Generating Nuclear Station and Peoria, IL from July 7, 1948 through December 31, 2012. See Design Input 4.1 for additional information on this file. After 1/1/1990 wind speed, wind direction, dew point temperature and dry-bulb temperature data were taken from an on-site meteorological tower at Braidwood Generating Nuclear Station. Humidity, precipitation type, cloud height, and cloud cover data were not available from the on-site meteorological tower, and were taken from a National Weather Service observing station at the Peoria, IL airport (approximately 100 miles southwest of Braidwood Generating Nuclear Station).

Prior to 1990, all data is taken from Peoria with the exception of a period from 1/1/1952 to 1/31/1956 which uses data from Springfield, IL since hourly data was not available from Peoria. This weather data file is input to LAKET-PC [Ref. 5.2 of Att. A], and the worst weather and worst net evaporation time periods are found from the range of dates included in this file.

LAKET-PC runs are made for determining the worst weather at the time periods to be included in the weather files. This includes the UHS transit time, the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and the worst 30 days. Therefore, worst weather periods are found for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months (4 pump UHS transit time), 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (3 pump UHS transit time), 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months (2 pump UHS transit time), and 30 days. Additionally, a LAKET-PC run is done to determine the worst 30 days for net evaporation. Due to options selected in the input file, the LAKET-PC run returns a plot file that includes the total evaporation (worst net evaporation cases only),

precipitation (worst net evaporation cases only), natural lake temperature, lake inlet temperature (same as the plant outlet temperature), and the UHS outlet temperature (same as the plant inlet temperature).

Since LAKET-PC returns results in three hour increments, a rolling average over the time period being analyzed (i.e., 24-hr, 36-hr, 48-hr, 30-days) is created using Microsoft Excel

[Ref. 5.1 of Att. A] by averaging the UHS outlet temperature of the selected time step along with the number of following time steps needed to comprise the analyzed time period (e.g., 7 additional time steps for worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ). The starting time of the worst weather for the analyzed time period is chosen as the time with the highest UHS outlet temperature rolling temperature average.

2.1 Worst 24-Hour, 36-Hour, 48-Hour and 30-Day Weather A specific UHS model was created in LAKET-PC (based on the input file from Case 3_12AM) with a transit time that corresponds to the three hour time step period. The model is open cycle, which means water exiting the lake is discarded and new water enters the lake at predetermined conditions independent of the existing lake conditions.

The UHS is set to the same initial temperature at the beginning of each three hour time step. Since initial conditions are the same for each time step, there are no residual effects due to the weather from the preceding time step. The UHS outlet temperature for each 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months period corresponds to the environmental effects on the UHS during these three

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A5 of A16 hours. From these results, it can be concluded that higher UHS outlet temperatures represent worse (hotter) weather conditions. The following changes were made to Case 3_12AM.dat to create Worst_Weather_100.dat and Worst_Weather_110.dat for determining the worst weather conditions:

The date range is changed to match the date range of weather file PIABWD4812.txt.

The initial lake temperature is set at 100°F or 110°F. (Assumption 3.1)

The model is set as open cycle, so the UHS is at the same temperature (the initial temperature of 100°F or 110°F) at the beginning of each 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months interval.

Anemometer height is set in accordance with the heights given Table 5 from Attachment B (Design Input 4.2). The FWINDZ function is used in LAKET-PC to vary the anemometer height over specified time periods.

Lake elevation is fixed at 590-ft (Assumption 3.2).

The plant flow is set at 1844.8 ft3/s to obtain a lake transit time of 3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months (Plant Flow

= Effective Lake Volume / Transit Time, 457.4 acre-ft

43,560 ft3/acre-ft / 10,800 s

= 1844.8 ft3/s).

The plant discharge water temperature (TPRISE variable in LAKET-PC) is set at 100°F (Assumption 3.3). For an open cycle model, this value is the lake inlet temperature.

The UHS outlet temperature for each 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months period corresponds to the environmental effects on the UHS during these three hours. From these results, it can be implied that higher UHS outlet temperatures represent worse (hotter) weather conditions.

2.2 Worst 30-Days of Net Evaporation For determining the worst 30-days of net evaporation, three UHS models are created (one for two SX pumps, one for three SX pumps, one for four SX pumps) in LAKET-PC based on Case 2_Evap.dat for two SX pumps, Case 3_Evap.dat for three SX pumps, and Case 4_Evap.dat for four SX pumps. The following changes were made to Case2_Evap, Case 3_Evap, and Case 4_Evap for determining the worst net evaporation conditions:

The date range is changed to match the date range of weather file PIABDW4812.txt.

Anemometer height is set in accordance with the heights given Table 5 from Attachment B (Design Input 4.2). The FWINDZ function is used in LAKET-PC to vary the anemometer height over specified time periods.

Lake elevation is fixed at 590-ft (Assumption 3.2).

Initial temperature is set at 90°F as a representative summer UHS temperature (Assumption 3.1).

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A6 of A16 The temperature rise through the plant (TPRISE variable in LAKET-PC) is set at the approximate average temperature rise of 9.5°F for two SX pumps, 7.1°F for three SX pumps, and 4.7°F for four SX pumps (Assumption 3.3).

The net evaporation is determined from output from the LAKET-PC runs as total evaporation less precipitation. The worst 30 days of net evaporation is determined using rolling averages, similar to the methodology used in determining the worst weather.

2.3 Weather File Creation for UHS Analysis Weather files are created based on the worst weather period determined by this analysis.

These weather files use the weather information provided in PIABDW4812.txt with the following changes:

The station code is set to zero. This input has no impact on the results of this analysis.

The start date and time is set at 7/1/1900 at 12AM. This input has no effect on the results of this analysis.

Synthetic weather files are created using weather data from the critical time period due to the design of the UHS (48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months with two SX pumps, 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months with three SX pumps, and 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for four SX pumps), the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and the worst 30 days. The start of the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and the worst 30 days is selected to maintain a 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months interval between time steps. For example, if the worst 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (critical time period) ends at 11PM, the next time step will be at 12AM of the beginning of the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

For the worst net evaporation, only one weather file will be created, corresponding to the dates and times determined to be the most limiting.

2.4 Computer Programs and Software LAKET-PC Version 2.2 [Ref. 5.2 of Att. A] was used to perform the lake transient analysis contained in this evaluation. This was run on S&L PC No. ZD6661 on Windows XP operating system for files dated prior to 2/22/2014, and it was run on S&L PC No.

ZD9392 on Windows XP operating system for files dated after 2/22/2014.

Postprocessing of the LAKET-PC results is done using Microsoft Excel 2010 [Ref. 5.1 of Att. A], which is commercially available. The validation of Excel is implicit in the detailed review of all spreadsheets used in this analysis.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A7 of A16 3.0 ASSUMPTIONS 3.1 Initial Lake Temperature - For the 24-hour, 36-hour, and 48-hour worst weather evaluation, the initial lake temperature is set at 110°F. For the 30-day worst weather evaluation, the initial lake temperature is set at 100°F. This matches the initial lake temperature with the assumed plant discharge water temperature (see Assumption 3.3).

For the worst net evaporation month, the initial lake temperature is assumed to be 90°F.

This is used as a representative value for the lake temperature during the summer since the weather data file begins on July 5.

3.2 Fixed Lake Elevation - The lake elevation when determining the worst weather month is fixed at 590-ft. A constant lake elevation removes the effects of lake level in determining the weather effects on the UHS temperature.

3.3 Station Thermal Boundary Condition - The plant discharge water temperature when determining the worst weather day and month is assumed to be 100°F for the 30-day case and 110°F for the 24-hr, 36-hr, and 48-hr cases. This is the approximate average lake temperature during these time periods. Since the lake is modeled as open cycle, the lake starts at this temperature at the start of each 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months time interval. A constant initial temperature allows for isolation of the meteorological effects on the lake.

When determining the worst net evaporation month, the temperature rise through the plant is assumed to be constant at 9.5°F for two SX pumps, 7.1°F for three SX pumps, and 4.7°F for four SX pumps. This is the approximate average plant temperature rise (TPRISE value) over the accident transient. The average plant temperature rise is determined using the TPRISE values from Case 12AM_2, Case 12AM_3 and Case 12AM_4 of the main body of this calculation, which were determined from the heat loads documented in Attachment C. A constant temperature rise through the plant removes the effects of the plant heat load in determining the evaporation.

3.4 Seepage - When determining the worst weather periods and worst net evaporation periods, seepage from the UHS is assumed to be the same as used in cases in the main body of this calculation. The seepage rate is 0.8 ft3/s.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A8 of A16 4.0 DESIGN INPUTS 4.1 Weather Data File - The LAKET-PC-compatible meteorological data file is developed from weather data from Braidwood Nuclear Generating Station and Peoria/Springfield from 7/5/1948 to 12/31/2012 in Attachment B. This file has the following properties:

Name: PIABDW4812.txt Size: 87,231 KB Creation date/time: 1/30/2014 8:18 AM CST 4.2 Anemometer Height - The anemometer height for the data entered in PIABDW4812.txt is provided in Attachment B.

Table 4-1 Historical Wind Sensor Height Beginning Date Ending Date Sensor Height (ft)

Primary Wind Data Source 7/5/1948 11/21/1948 26 NWS-Peoria (KPIA) 11/22/1948 12/31/1951 50 NWS-Peoria (KPIA) 1/1/1952 12/31/1956 49 NWS-Springfield (KSPI) 1/1/1957 9/30/1959 50 NWS-Peoria (KPIA) 10/1/1959 12/31/1989 20 NWS-Peoria (KPIA) 1/1/1990 12/31/2012 34 On-site meteorological tower

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A9 of A16

5.0 REFERENCES

5.1 Microsoft Office Excel 2010, Sargent & Lundy LLC Program No. 03.2.435-14.0, dated 7/1/2010.

5.2 LAKET-PC Computer Program, Version 2.2, S&L Program No. 03.7.292-2.2, 7/31/2013.

Controlled File Path: \\\\SNLVS5\\SYS3\\OPS$\\LAK29222\\

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A10 of A16 6.0 CALCULATIONS AND RESULTS Analysis of rolling averages determine the worst 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , 36 hour4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months and 30 day period for UHS temperature and the worst 30 day period for net evaporation for the weather file.

6.1 Worst Weather Conditions The average lake temperature over the worst 30 days is approximately 100°F. Therefore, the worst weather selection for the worst 30-day period is based on an initial UHS temperature of 100°F. The UHS analysis will be done starting at eight different times, so the worst 30 days time period is determined for each start time.

Table 6-1: Worst 30-Day Weather Results Start Time Worst 30-day Start Date 12AM 7/10/2011 3AM 7/9/2011 6AM 7/9/2011 9AM 7/9/2011 12PM 7/9/2011 3PM 7/9/2011 6PM 7/9/2011 9PM 7/9/2011 The average UHS temperature for the first two days following an accident is approximately 110°F. Therefore, the worst weather selection for the worst 24-hr, 36-hr, and 48-hr time periods are based on an initial UHS temperature of 110°F. The UHS analysis will be done starting at eight different times, so the worst 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , 36 hour4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , and 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months time periods are determined for each start time.

Table 6-2: Worst 24-hr, 36-hr, and 48-hr Weather Results Start Time Worst 24-hr Start Date Worst 36-hr Start Date Worst 48-hr Start Date 12AM 6/23/2009 7/6/2012 7/5/2012 3AM 6/23/2009 7/6/2012 7/5/2012 6AM 7/19/2011 7/6/2012 7/5/2012 9AM 7/6/2012 6/22/2009 6/22/2009 12PM 7/6/2012 6/22/2009 7/5/2012 3PM 7/6/2012 6/22/2009 7/5/2012 6PM 7/6/2012 7/5/2012 7/5/2012 9PM 7/26/1999 7/5/2012 7/5/2012 6.2 Worst Net Evaporation LAKET-PC input files Worst_NetEvap-2.dat, Worst_NetEvap-3.dat, and Worst_NetEvap-4.dat were compiled to determine the worst 30-day period of net

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A11 of A16 evaporation from 7/5/1948 to 12/31/2012. Using the results from LAKET-PC, the worst 30-day period in terms of net evaporation for all cases was determined to be the period beginning at 6/1/1988 at 9AM. Since the worst net evaporation occurs on the same day for each number of SX pumps in operation, a single 30 day weather file, Net_Evap.txt, will be created starting at 6/1/1988 9AM.

6.3 Weather File Creation for UHS Analysis Weather files are created for two SX pumps in operation, three SX pumps in operation, and four SX pumps in operation. For two pumps, the transit time through the UHS is approximately 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months , so the synthetic weather file consists of the worst 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months , worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and worst 30 days. For three pumps, the transit time through the UHS is approximately 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , so the synthetic weather file consists of the worst 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and worst 30 days. For four pumps, the transit time through the UHS is approximately 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , so the synthetic weather file consists of the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , and worst 30 days. Weather files are created for eight different start times (12AM, 3AM, 6AM, 9AM, 12PM, 3PM, 6PM, and 9PM) for two, three, and four pump operation. In addition, a weather file is created for the worst 30 days of net evaporation.

Table 6-3: 2 Pump Operation Weather Files Case 48-Hour Start 48-Hour End 24-Hour Start 24-Hour End 30-Day Start 30-Day End 12AM_3 7/5/12 12AM 7/6/12 11PM 6/23/09 12AM 6/23/09 11PM 7/10/11 12AM 8/8/11 11PM 3AM_3 7/5/12 3AM 7/7/12 2AM 6/23/09 3AM 6/24/09 2AM 7/9/11 3AM 8/8/11 2AM 6AM_3 7/5/12 6AM 7/7/12 5AM 7/19/11 6AM 7/20/11 5AM 7/9/11 6AM 8/8/11 5AM 9AM_3 6/22/09 9AM 6/24/09 8AM 7/6/12 9AM 7/7/12 8AM 7/9/11 9AM 8/8/11 8AM 12PM_3 7/5/12 12PM 7/7/12 11AM 7/6/12 12PM 7/7/12 11AM 7/9/11 12PM 8/8/11 11AM 3PM_3 7/5/12 3PM 7/7/12 2PM 7/6/12 3PM 7/7/12 2PM 7/9/11 3PM 8/8/11 2PM 6PM_3 7/5/12 6PM 7/7/12 5PM 7/6/12 6PM 7/7/12 5PM 7/9/11 6PM 8/8/11 5PM 9PM_3 7/5/12 9PM 7/7/12 PAM 7/26/99 9PM 7/27/99 8PM 7/9/11 9PM 8/8/11 8PM Table 6-4: 3 Pump Operation Weather Files Case 36-Hour Start 36-Hour End 24-Hour Start 24-Hour End 30-Day Start 30-Day End 12AM_3 7/6/12 12AM 7/7/12 11AM 7/6/12 12PM 7/7/12 11AM 7/9/11 12PM 8/8/11 11PM 3AM_3 7/6/12 3AM 7/7/12 2PM 7/6/12 3PM 7/7/12 2PM 7/9/11 3PM 8/9/11 2AM 6AM_3 7/6/12 6AM 7/7/12 5PM 7/6/12 6PM 7/7/12 5PM 7/9/11 6PM 8/9/11 5AM 9AM_3 6/22/09 9AM 6/22/09 8PM 7/26/99 9PM 7/27/99 8PM 7/9/11 9PM 8/9/11 8AM 12PM_3 6/22/09 12PM 6/23/09 11PM 6/23/09 12AM 6/23/09 11PM 7/10/11 12AM 8/9/11 11AM 3PM_3 6/22/09 3PM 6/24/09 2AM 6/23/09 3AM 6/24/09 2AM 7/9/11 3AM 8/8/11 2PM 6PM_3 7/5/12 6PM 7/7/12 5AM 7/19/11 6AM 7/19/09 5AM 7/9/11 6AM 8/8/11 5PM 9PM_3 7/5/12 9PM 7/7/12 8AM 7/6/12 9AM 7/7/12 8AM 7/9/11 9AM 8/8/11 8PM

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A12 of A16 Table 6-5: 4 Pump Operation Weather Files Case 24-Hour Start 24-Hour End 24-Hour Start 24-Hour End 30-Day Start 30-Day End 12AM_4 6/23/09 12AM 6/23/09 11PM 6/23/09 12AM 6/23/09 11PM 7/10/11 12AM 8/8/11 11PM 3AM_4 6/23/09 3AM 6/24/09 2AM 6/23/09 3AM 6/24/09 2AM 7/9/11 3AM 8/8/11 2AM 6AM_4 7/19/11 6AM 7/20/11 5AM 7/19/11 6AM 7/20/11 5AM 7/9/11 6AM 8/8/11 5AM 9AM_4 7/6/12 9AM 7/7/12 8AM 7/6/12 9AM 7/7/12 8AM 7/9/11 9AM 8/8/11 8AM 12PM_4 7/6/12 12PM 7/7/12 11AM 7/6/12 12PM 7/7/12 11AM 7/9/11 12PM 8/8/11 11AM 3PM_4 7/6/12 3PM 7/7/12 2PM 7/6/12 3PM 7/7/12 2PM 7/9/11 3PM 8/8/11 2PM 6PM_4 7/6/12 6PM 7/7/12 5PM 7/6/12 6PM 7/7/12 5PM 7/9/11 6PM 8/8/11 5PM 9PM_4 7/26/99 9PM 7/27/99 8PM 7/26/99 9PM 7/27/99 8PM 7/9/11 9PM 8/8/11 8PM Table 6-6: Worst Net Evaporation Weather Files Case Start Date End Date Net_Evap 6/1/1988 9AM 7/1/1988 8AM The natural lake temperature refers to the temperature of the lake if it is reacting to purely natural influences. The initial natural lake temperature is the initial temperature of the lake that is not in the participating part of the UHS. This is the portion of the UHS that does not see the plant heat load, or the non-effective portion. This constitutes 17.7% of the UHS since the UHS effectiveness is 82.3% (see main body Design Input 4.4). The initial natural temperature for each case is taken to be the natural temperature of the lake at the time step of the start date of the weather file. The natural lake temperature at these time steps is found in the results of the Worst_Weather_110 case from the file Worst_Weather_110.pltX. These natural lake temperatures will be used to set the initial natural lake temperature in the worst weather LAKET-PC runs made in the main body of this calculation. The initial natural temperatures are summarized in the table below.

Table 6-7: Natural Lake Temperature Case 2 Pumps

(°F) 3 Pumps

(°F) 4 Pumps

(°F) 12AM 97.38 98.47 96.30 3AM 96.80 97.84 95.57 6AM 96.88 98.05 95.59 9AM 95.16 95.16 99.57 12PM 100.11 97.06 101.40 3PM 100.81 98.09 102.07 6PM 99.87 99.87 101.51 9PM 99.08 99.08 100.06 Net_Evap 84.61 84.61 84.61

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A13 of A16 7.0

SUMMARY

AND CONCLUSIONS The worst weather 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period, 36 hour4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months period, 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months period, and 30 day period were determined by running LAKET-PC over a range of days spanning from 7/5/1948 to 12/31/2012. These worst weather periods were determined for eight different start times.

For the worst 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , worst 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , and worst 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months , the worst weather period started on several different dates depending on the start time. These worst weather periods are summarized in Tables 6-1 and 6-2. The worst 30 day weather period started on 7/9/2011 or 7/10/2011 for all start times.

The worst 30 day period for net evaporation was also determined using LAKET-PC. It was determined that the 30 days starting at 6/1/1988 at 9AM results in the worst net evaporation for two, three, or four SX pumps in operation.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A14 of A16 8.0 APPENDICES List of Appendices App.

Description No. of Pages 8.1 Electronic File Listing 1

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A15 of A16 Appendix 8.1: Electronic File Listing Appendix 8.1: Electronic File Listing A summary of the electronic files and their purposes is provided below:

Worst Weather Screening Files File Name Size Date Worst_Weather_100.dat 1 KB 2/3/2014 2:54 PM Worst_Weather_100.out 1,131 KB 2/3/2014 2:55 PM Worst_Weather_100.pltX 11,042 KB 2/3/2014 2:55 PM Worst_Weather_110.dat 1 KB 2/3/2014 2:55 PM Worst_Weather_110.out 1,131 KB 2/3/2014 2:56 PM Worst_Weather_110.pltX 11,042 KB 2/3/2014 2:56 PM Worst Net Evaporation Screening Files File Name Size Date Worst_NetEvap-2.dat 1 KB 5/7/2014 1:00 PM Worst_NetEvap-2.out 1,131 KB 5/7/2014 1:02 PM Worst_NetEvap-2.pltX 15,827 KB 5/7/2014 1:02 PM Worst_NetEvap-3.dat 1 KB 5/7/2014 1:26 PM Worst_NetEvap-3.out 1,131 KB 5/7/2014 1:28 PM Worst_NetEvap-3.pltX 15,827 KB 5/7/2014 1:28 PM Worst_NetEvap-4.dat 1 KB 5/7/2014 1:29 PM Worst_NetEvap-4.out 1,131 KB 5/7/2014 1:30 PM Worst_NetEvap-4.pltX 15,827 KB 5/7/2014 1:30 PM Weather Files File Name Size Date 12AM_2.txt 123 KB 3/13/2014 8:10 AM 3AM_2.txt 123 KB 3/13/2014 8:12 AM 6AM_2.txt 123 KB 3/13/2014 8:14 AM 9AM_2.txt 123 KB 3/13/2014 8:16 AM 12PM_2.txt 123 KB 3/13/2014 8:21 AM 3PM_2.txt 123 KB 3/13/2014 8:22 AM 6PM_2.txt 123 KB 3/13/2014 8:23 AM 9PM_2.txt 123 KB 3/13/2014 8:24 AM 12AM_3.txt 123 KB 2/4/2014 3:59 PM 3AM_3.txt 123 KB 4/14/2014 4:19 PM 6AM_3.txt 123 KB 2/4/2014 4:06 PM 9AM_3.txt 123 KB 2/4/2014 4:09 PM 12PM_3.txt 123 KB 2/4/2014 4:11 PM 3PM_3.txt 123 KB 2/4/2014 4:12 PM 6PM_3.txt 123 KB 2/4/2014 4:15 PM

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT A, PAGE A16 of A16 Appendix 8.1: Electronic File Listing File Name Size Date 9PM_3.txt 123 KB 2/4/2014 4:16 PM 12AM_4.txt 120 KB 2/4/2014 4:22 PM 3AM_4.txt 120 KB 2/4/2014 4:27 PM 6AM_4.txt 120 KB 2/4/2014 4:28 PM 9AM_4.txt 120 KB 2/4/2014 4:29 PM 12PM_4.txt 120 KB 2/4/2014 4:30 PM 3PM_4.txt 120 KB 2/5/2014 8:06 AM 6PM_4.txt 120 KB 2/5/2014 8:08 AM 9PM_4.txt 120 KB 2/5/2014 8:09 AM NetEvap.txt 112 KB 5/7/2014 2:58 PM

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT 8, PAGE 81of847 Attachment B Update Hourly Meteorological Data Used for Cooling Lake Analysis Reviewed: --~-----__.._/_====2=------'-* _____ Date Daniel P. Laubenthal - Sargent & LundlLc

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B2 of B47 1.0 PURPOSE / OBJECTIVE This attachment describes preparation of an updated meteorological data file used to support a LAKET-PC analysis for the Braidwood Nuclear Generating Station, near Braidwood, IL. The original UHS Analysis meteorological data file covers the period from 1948 through 1976. This update accomplishes two things:

Adds data for 1977 through December 31, 2012. The resulting file includes data for July 5, 1948 through December 31, 2012.

Uses data from an on-site meteorological tower for January 1, 1990 through December 31, 2012.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B3 of B47 2.0 PARAMETERS INCLUDED IN THE METEOROLOGICAL DATA FILE The updated file is compatible with the LAKET-PC program, which S&L uses to evaluate the thermal performance of cooling lakes. The parameter content and digital format of LAKET-PC meteorological files are listed in Table 1.

3.0 EXISTING METEOROLOGICAL DATA FILE The existing file used data from the National Weather Service (NWS) in Peoria, IL (KPIA), with exception of a period from January 1, 1952 - December 31, 1956 which used NWS data from Springfield, IL (KSPI). Springfield, IL data were used because hourly data were not available from Peoria during that time. The specifications of the existing file are provided for reference below:

Existing meteorological data file:

Name: PS489661.TXT Type: ASC text Size: 64,905 Kb File creation date/time: 4/6/2006 8:16 AM 4.0 METEOROLOGICAL DATA SOURCES USED TO UPDATE THE EXISTING DATA FILE The updated file uses a combination of data from KPIA and an on-site multi-level instrumented tower at the Braidwood generating station. For January 1, 1990 through December 31, 2012, the on-site multi-level tower is the primary source of wind speed/direction, dry bulb temperature, and dew point temperature data. When those four parameters are not available from the tower, they are taken from KPIA.

For January 1, 1990 through December 31, 2012, KPIA is the primary source of parameters required for LAKET-PC, but not measured by the on-site tower. These parameters include cloud cover, cloud height and precipitation type.1 Hourly precipitation is also taken from KPIA for consistency with the reported precipitation type and cloud observations. Primary and secondary data sources used in the updated meteorological data file are summarized in Table 2.

The on-site tower is instrumented at 30-34 ft. levels and the 199-203 ft. levels. The tower instrumentation configuration is summarized in Table 3. Since LAKET-PC requires data near the surface, the updated meteorological data file uses the dry bulb and dew point temperatures recorded at the 30-foot level and the wind speed/direction at the 34-foot level.

1 These parameters are generally not measured by on-site meteorological towers used at nuclear facilities.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B4 of B47 5.0 RAW METEOROLOGICAL DATA USED TO UPDATE THE EXISTING DATA FILE The raw data for the on-site tower were available from S&L (2014). Raw meteorological data from KPIA were obtained from the National Climatic Data Center (NCDC). The data consist of surface weather observations and hourly precipitation data. These data are briefly described below.

(1)

Surface Weather Observations Raw surface weather observations in DS-3505 format (NCDC 2006) from KPIA covered January 1, 1990 through December 31, 2012. NCDC subjects meteorological data to rigorous quality control checks before archival (Del Greco et al. 2006). However, meteorological databases may occasionally include gaps and data values outside of valid ranges. The archived data included most of the weather parameters required by LAKET-PC (Table 1), with the following exceptions: solar radiation, atmospheric radiation, binary (zero or one) freezing precipitation code, and the partial pressure of water vapor.

The binary precipitation code depends upon present weather type reported in surface weather observations. S&L estimated solar radiation using the approach of Meyers and Dale (1983). Atmospheric radiation was computed using methodology described by Jirka et al. 1978. The partial pressure of water vapor was computed using ASHRAE (1975),

which implements the procedure described by List (1951). Formulation and validation of the algorithms used to compute solar radiation, atmospheric radiation, freezing precipitation code, and the partial pressure of water vapor are described below in Section

10.

(2)

Precipitation Data Raw hourly digital precipitation data in DS-3240 and text format (NCDC 2000 and NCDC 2012) from KPIA were available for January 1, 1990 through December 31, 2012.

Since the project required combining wind speed/direction, dry bulb temperature, and dew point temperature from an on-site meteorological tower with data collected KPIA, S&L developed a project-specific FORTRAN program which merged data from the on-site tower with data from KPIA. The program produced input files subsequently processed as described below.

6.0 CREATING INPUT METEOROLOGICAL DATA FOR LAKET-PC S&L uses a series of modular computer programs collectively called the Surface Data Generator ("SURGEN") (S&L 1997) and judgments and adjustments by a qualified, experienced, professional meteorologist to create digital meteorological data files for input into LAKET-PC. Key requirements of LAKET-PC include a specific set of weather parameters and specific digital format (Table 1), and a complete meteorological

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B5 of B47 database with no bad (out of range), or missing, parameters. SURGEN modules are executed independently and perform the following functions:

Interpret the unique digital formats of raw surface weather observations and precipitation data and extract required meteorological parameters.

Convert numeric units of extracted parameters to those required by the LAKET-PC program.

Scan hourly surface weather observations, and identify periods when values for selected parameters are either missing or invalid (outside of acceptable ranges).

Those periods are identified by starting and ending date, and by the length of each gap (in hours).

Scan hourly surface weather observations, identify periods within the digital file when whole days or specific hours are missing; insert new, or blank records into the file to fill time gaps.

Estimate values for the following weather parameters: an indicator whether precipitation is liquid or frozen, solar radiation reaching the lake surface, atmospheric radiation reaching the lake surface, partial pressure of water vapor in the atmosphere, wet bulb temperature and dew point temperature.

Perform simple linear interpolation of weather parameter values through short data gaps, and insert the new interpolated values into the database.

Allow insertion of manually selected substitution values into gaps in the database that are judged not to be suitable for simple linear interpolation.

Translate processed and adjusted databases into the format required by the LAKET-PC program.

7.0 REVIEW AND ADJUSTMENT OF METEOROLOGICAL DATA As noted above, SURGEN identified short periods of missing, or bad (out of range), raw meteorological data and used linear interpolation to fill short gaps. The gaps were generally 1-2 hours long. However, there were a number of gaps in the on-site meteorological tower data that were considered to be too long for linear interpolation.

Data were manually substituted from KPIA for those periods. Those periods are listed in Table 4. If either the wind speed, or wind direction, was missing from the on-site data, then both the wind speed and direction were substituted from KPIA so that the substituted wind vector consisted of a wind speed and wind direction from the same location.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B6 of B47 To check the thermodynamic consistency of the meteorological data, S&L computes the hourly wet bulb temperature and relative humidity from the dry bulb and dew point temperature to ensure thermodynamic consistency among the temperature and humidity parameters. In cases when the dew point temperature from KPIA is substituted for a missing dew point reading from the on-site tower, and the dew point temperature from KPIA exceeds the on-site dry bulb temperature, the substituted dew point temperature is set equal to the on-site dry bulb temperature before computing the wet bulb temperature and relative humidity.

8.0 LAKET-PC METEOROLOGICAL DATA INPUT FILE SURGEN produced a single LAKET-PC meteorological input file which was appended to the existing meteorological data text file. The specifications of the updated LAKET-PC meteorological data file are listed below:

Updated meteorological data file:

Name: PIABDW4812.TXT Type: ASC text Size: 87,231 Kb File creation date/time: 1/30/2014 8:18 AM 9.0 WIND SENSOR HEIGHT The wind speed/direction sensor height is an input in the LAKET-PC program. The wind sensor height (NCDC 2002) changed a number of times during the 1948-2012 period of record of the input meteorological data file. The historical wind sensor height is listed in Table 5. Some of the changes in wind sensor height are due to changes in the wind instrumentation at KPIA, while others are due to changes in the primary wind data source.

Wind speed data from KPIA were collected at the 20 ft. level during October 1, 1959 through September 30, 1995. Because 34-ft wind speed data were occasionally not available from the on-site meteorological tower during December 1, 1990 through September 30, 1995 (Table 4), it is necessary to combine relatively short periods of wind speed data from KPIA (20 ft. anemometer height) with wind speed data from the on-site tower (34 ft. anemometer height) for the January 1, 1990 through September 30, 1995 period. Although the anemometer height of the on-site tower differed from the anemometer height at KPIA during that period, LAKET-PC is expected to produce conservative results when using winds from KPIA since 20-ft. level wind speeds are expected to be less than wind speeds at the 34-ft level.

The anemometer height at KPIA was increased to its current height of 32.8 feet on October 1, 1995. The anemometer height at KPIA (32.8 ft.) is considered to approximate the anemometer height of the lowest level of the on-site tower (34 ft.) for the period from October 1, 1995 through December 31, 2012.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B7 of B47 10.0 FORMULATION AND VALIDATION OF ALGORITHMS FOR COMPUTING SOLAR RADIATION, ATMOSPHERIC RADIATION, FREEZING PRECIPITATION CODE, AND PARTIAL PRESSURE OF WATER VAPOR This section describes formulation and validation of algorithms used to compute solar radiation, atmospheric radiation, the freezing precipitation code, and the partial pressure of water vapor. The theoretical basis of each algorithm is described first, followed by validation.

10.1 Theoretical Basis for Algorithms 10.1.1 Estimation of Solar Radiation Reaching the Ground Surface Computed solar radiation is a new analysis input for the Braidwood Nuclear Generating Station. The following approach is used to compute solar radiation. The approach follows the methods of Meyers and Dale (1983). Those methods were developed by the Midwest Agricultural Weather Center of the Department of Agronomy at Purdue University (West Lafayette, Indiana). The methods include a semi-physical model based on standard meteorological data. The radiation model includes the effects of: Rayleigh scattering, absorption by water vapor and permanent gases, and absorption and scattering by aerosols and clouds. Cloud attenuation is accounted for by assigning transmission coefficients based on cloud height and amount. The model was tested by Meyers and Dale with independent data from West Lafayette and Indianapolis Indiana, Madison Wisconsin, Omaha Nebraska, Columbia Missouri, Nashville Tennessee, Seattle Washington, Los Angeles California, Phoenix Arizona, Lake Charles Louisiana, Miami Florida, and Sterling Virginia. Excellent agreement was obtained for all stations tested.

The models performance judged by relative error was found to be independent of season and cloud amount for all seasons tested.

From Meyers and Dale (1983):

RAD = (Io) (Ta) (TR) (Tg) (Tw) [ 1+(alb) (ca) ] (cov) (cos(Z)) (221.13) [ (1-cov) + (cov)

(Ti) ]

Where:

RAD = irradiance at the ground, including the effects of a cloud layer [ BTU/(ft2 hr) ]

Io = extraterrestrial radiation flux at the top of the atmosphere on a surface normal to the incident radiation (W / m2)

= (1353 ) [ 1+ (0.034) [ cos [ (6.28318) (n-1) / 365 ] ]

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B8 of B47 1353 = conversion factor to produce results in numeric units of (W / m2) 221.13 = conversion factor to convert radiation numeric units from (Langley/min) to [BTU/( ft2 hr)]

Transmission coefficients:

Ta = transmission coefficient after absorption and scattering by aerosols

0.925 M Tw = transmission coefficient after absorption by water vapor

1 - (0.077) [ (u)(M) ] 0.3 TR = transmission coefficient after Rayleigh (air molecule) forward scattering Tg = transmission coefficient after absorption by permanent gases (TR) (Tg) = 1.021 - [ (0.084) [ (M) [ (949) (p) (10 -5) + 0.051 ] ] 0.5 ]

Ti = transmission coefficient after absorption by clouds as follows:

Cloud layer Cloud coverage height range (ft.)

(tenths)

Ti

>= 0

< 1000 0 < cov <= 9.50

>= 0

< 1000

=10

.15

>= 1000 < 4000 0 < cov <= 9.629

>= 1000 < 4000

=10

.312

>= 4000 < 10000 0 < cov <= 9.525

>= 4000 < 10000

=10

.414

>= 10000 < 18000 0 < cov <= 9.534

>= 10000 < 18000

=10

.455

>= 18000 < 30000 0 < cov <= 9.746

>= 18000 < 30000

=10

.668

>= 30000 0 < cov <= 9.90

>= 30000

=10

.85

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B9 of B47 Other parameters:

alb = ground surface albedo

= 0.2 with no snow cover

= 0.65 with snow cover ca = cloud albedo

= 0.5 for cloud base < 5486 m (18000 ft.)

= 0.0 for cloud base >= 5486 m (18000 ft.)

Parameter s that is used to estimate precipitable water is defined as follows:

Site location Season latitude zone ----------------------------------------------

(degrees north) winter spring summer autumn

>00 and <=10 3.37 2.85 2.80 2.64

>10 and <=20 2.99 3.02 2.70 2.93

>20 and <=30 3.60 3.00 2.98 2.93

>30 and <=40 3.04 3.11 2.92 2.94

>40 and <=50 2.70 2.95 2.77 2.71

>50 and <=60 2.52 3.07 2.67 2.93

>60 and <=70 1.76 2.69 2.61 2.61

>70 and <=80 1.60 1.67 2.24 2.63

>80 and <=90 1.11 1.44 1.94 2.02 Season definitions as follows:

Julian day season

> 80 and <= 173 spring

> 173 and <= 264 summer

> 264 and <= 355 autumn

> 0 and <= 80 winter or

> 355 and <= 366 n = Julian day (1 - 366) p = surface atmospheric pressure (kPa)

Td = surface dew point temperature (°F) y = site location latitude d = declination angle of the sun (radians)

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B10 of B47 H = hour angle M = optical air mass at a pressure of 101.3 kPa

= (35) / ( (1224) (cos 2 Z) + 1 ) 0.5 u = precipitable water vapor = exp(0.1133 - loge(s+1) + (0.0393) (Td))

ZEN = solar zenith angle = 90° - (sin -1 (sin(y) sin(d) + cos(y) cos(d) cos(H)))

Z = solar zenith angle (in units of radians) = (ZEN) (6.28318/360)

(6.28318)(1/360) = multiplication factor to convert degrees to radians cov = coverage of a cloud layer (0.0 - 1.0) 10.1.2 Estimation of Ground Snow Cover It was necessary to include in the program an algorithm for estimating hourly snow cover, because the presence of snow cover is a component of the solar radiation algorithm. A description of ground snow cover is included in this section to provide a complete technical description of the solar radiation algorithm. However, the ground snow cover algorithm would not be exercised for certain applications of LAKET-PC, such as summertime maximum lake temperature analysis.

An algorithm was created to approximate snow accumulation. It was based on analysis of observations during four winters at Peoria, Illinois (NCDC 1989(b), 1990, 1991, 1992). A simple linear equation for snow depth was created from those data. Table 6 presents snow and temperature data from Peoria, Illinois that were used to construct a snow accumulation algorithm. Each row of data in Table 6 summarizes conditions during a snow event. Although the equation that was based on those data was intended to be applied to hourly weather conditions, the data used to construct the equation were based on the total snowfall on the ground during the event, and the maximum air temperature observed during the event. This approach was taken because available data included only one daily observation of snow depth on the ground. It was expected that the slope of the equation would be approximately the same regardless of whether hourly data during an event or data summarizing the entire event were used to construct the equation.

The program tracks snow depth from hour to hour. The depth of snow on the ground is increased when snow is observed and it has a finite amount greater than zero or a trace.

When snow is observed, the rate of depth increase is based on the rate of water equivalent precipitation and the air temperature. After snowfall ends, the depth of snow is decreased

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B11 of B47 on an hourly basis according to air temperature. When snow depth is non-zero, snow cover is present for purposes of input to the solar radiation algorithm.

Any of the following weather types are considered snow that affects the ground snow depth.

Any type of snow (light, moderate, or heavy)

Any type of snow pellets Any type of snow shower Any type of snow squall Any type of snow grains For any hour reporting on of the above types of precipitation, the accumulation of snow depth on the ground during that hour is predicted with the following equation:

Hourly increase in snow depth (inches) = (A) (-B)

Where:

A = Hourly water equivalent precipitation (inches)

B = (C-44.4) / (1.39)

C = Hourly air temperature (°F)

A negative hourly snow depth increase is not allowed to occur. That is, no snow depth increase is predicted if the air temperature is greater than or equal to 44.4 °F.

Theory was found to indicate that the process of snow depth reduction involves a complex heat balance, and is a function of cloud cover, solar angle, air temperature, and humidity (Colbeck 1980; Geiger 1965). An existing snow depth reduction algorithm was not located.

A simple method was selected to construct an algorithm to simulate combined melting and sublimation of snow. It was based on examination of winter data from Madison, Wisconsin (NCDC 1988(a), 1989(a)). Values for rates of snow depth reduction were derived from the 1988 Madison daily snow depth information by plotting temperature versus snow melt for periods during which there was still snow on the ground after melting. This was done for January, February, and December, 1988. Trends were subjectively identified, and amounts of melting were selected for each of several temperature ranges. Table 7 presents data that were used to construct the snow melt algorithm.

Reduction of snow depth uses as input hourly temperature data, and an indication whether there exists snow cover and its depth. The following table describes the snow depth decrease per hour predicted by the algorithm for each of six dry bulb temperature

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B12 of B47 ranges. No reduction is predicted when the temperature is less than the lower end of the lowest range.

Snow Melt Rates Predicted by the Program Dry Bulb Temperature Snow Depth Decrease Range (°F)

Per Hour (inches) 10 - 19 0.021 19 - 32 0.042 32 - 36 0.083 36 - 41 0.166 41 - 46 0.333

> 46 0.667 The snow depth and snow accumulation algorithms operate simultaneously in the program, as it advances through hourly meteorological data.

10.1.3 Estimation of Atmospheric Radiation Reaching the Ground Surface Infrared radiation emitted by the Earths surface is partially absorbed by the water vapor of the atmosphere, which re-emits it. A portion of that re-emitted radiation is in a downward direction. It is absorbed by the ground and re-emitted upwards (Huschke 1980). Therefore, atmospheric infrared radiation is an important component of the radiation balance of a cooling lake water surface. The equation used by the program to estimate atmospheric radiation reaching the ground is as follows (Jirka et al., 1978):

R = [(1.16) (10) -13 / 24] [460 + T]6 [1 + ((0.17) (C2))]

Where:

R = Atmospheric radiation (BTU/(ft2 hr))

T = Air temperature (°F)

C = Cloud cover (tenths, e.g., 0.8 represents 8/10) 10.1.4 Freezing Precipitation Code LAKET-PC requires input hourly meteorological data. The meteorological data are produced by the SURGEN program (S&L (1997)). SURGEN extracts meteorological parameters from raw hourly surface weather observations and writes the extracted parameters to a LAKET-PC-compatible meteorological data file.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B13 of B47 LAKET-PC performs solar radiation computations which require estimates of hourly snow cover. Estimation of hourly ground snow cover is described in detail in section 10.1.2 of this report. Per section 10.1.2, LAKET-PC requires an input (precipitation type) related to the occurrence of precipitation that affects hourly snow cover.

Precipitation type (e.g., rain, snow, freezing rain) is included in raw hourly surface weather observations. Precipitation type is represented by a numerical code in surface weather observations (NCDC (2005)). Numerical precipitation type codes corresponding to freezing or frozen precipitation are listed in Table 8.

SURGEN reads raw meteorological data files, which include the precipitation type, and writes a binary (0 or 1) precipitation code to the output LAKET-PC-compatible meteorological file. SURGEN writes a binary precipitation code of one (1) when one of the precipitation codes in Table 8 is found in an input hourly weather observation.

Otherwise, SURGEN writes a code of zero (0).

10.1.5 Partial Pressure of Water Vapor LAKET-PC requires the partial pressure of water vapor in some of its computations. The partial pressure of water vapor is related to relative humidity and the saturation vapor pressure of water (e.g., Hess (1979)). The saturation vapor pressure of water is a function of atmospheric dry-bulb temperature (e.g., Iribarne and Godson (1981)). The relative humidity and dry-bulb temperature are included in hourly surface weather observations (NCDC (2005)).

SURGEN (S&L (1997)) processes hourly surface weather observations and produces LAKET-PC-compatible meteorological data input files which include the partial pressure of water vapor. SURGEN uses a FORTRAN subroutine PVSF (ASHRAE (1975);

Figure 1) to compute the partial pressure of water vapor. PVSF uses equations from List (1951). The logic of the FORTRAN subroutine is described below.

Input The subroutine PVSF requires the dry-bulb temperature x in Fahrenheit Output The subroutine PVSF returns the partial pressure of water vapor at saturated conditions (in inches, Hg.), VAPPR Description of the Algorithm The vapor pressure of water in saturated air (in inches, Hg.) is defined as:

VAPPR = 29.921 x 10(P1+P2+P3+P4) (Eq. 1)

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B14 of B47 where the parameters P1 through P4 depend on dry-bulb temperature x as described below.

First, the constants A1 through A6 and B1 through B4 are defined according to Table 9.

Next, define T = (x+459.688)/1.8, which is the dry-bulb temperature in Kelvin.

If T < 273.16 K, then define Z = 273.16/T and determine the parameters P1 through P4 in Eq. 1 from Table 10.

If T >= 273.16 K, then define Z = 373.16/T and determine the parameters P1 through P4 in Eq. 1 according to Table 11.

The subroutine computes the vapor pressure of water vapor at saturation, VAPPR, using Eq. 1 and returns the computed value of VAPPR to the calling program.

The partial pressure of water vapor is found in SURGEN from the relative humidity (RH) and the vapor pressure of water in saturated air (VAPPR) using the following equation (e.g., Hess (1979); page 60):

e = VAPPR x (RH/100). (Eq. 2) 10.2 Validation Validation of the atmospheric radiation algorithm was accomplished by manual calculations. The original source reference for the method (Jirka et al. 1978) was relied on as a validation of the theoretical approach. Performance of manual calculations versus computer calculations was expected to be very good in that case, within a couple of percent, because the calculations should not introduce significant uncertainty.

Validation of the integrated snow cover and solar radiation algorithms was accomplished via comparison of program predictions with randomly selected field observations of actual solar radiation phenomena. Performance in those cases was expected to be generally better than 70 percent. That expectation was based on the absolute errors reported by the authors of the theoretical basis in Table 7 of their technical paper (Meyers and Dale 1983).

Validation of the freezing precipitation code was performed by comparing program output with input raw surface weather observations. Validation of the partial pressure of

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B15 of B47 water vapor was performed by comparing results from SURGEN with a manual computation a published tabular value of vapor pressure.

10.2.1 Solar Radiation Reaching the Ground Surface - Validation The solar radiation algorithm was validated via comparison of program predictions with solar radiation observations made by the National Oceanic and Atmospheric Administration (NOAA).

Table 12 through Table 15 present lists of processed weather data created by the program, for Madison Wisconsin, for the following dates: 25 January 1988, 28 July 1988, 30 July 1988, and 15 September 1988. Column 13 of the lists contains data labeled SWRAD, meaning shortwave solar radiation in units of BTU/(ft2 hr). Column 1 indicates hours of day.

Table 16 through Table 18 present lists of NOAA Madison, Wisconsin solar radiation measurements at Madison Wisconsin for months January 1988, July 1988, and September 1988 (NCDC 1988(b)). Table rows identify days of month. Table columns identify hours of day.

Conversion of the NOAA solar radiation measurements from units of (Watt-hr m-2) to (BTU/(ft2 hr)) to match program output numeric units was accomplished manually as follows.

A Langley is a unit of energy per unit area 1 Langley = 11.622 Watt-hr per square meter 1 Langley = 3.687 British thermal units per square foot To convert NOAA radiation measurements to BTU/(ft2 hr), a multiplication factor must be applied, as follows:

(Watt-hr m-2) / 11.622 = (Langleys)

(Langleys) (3.687) = BTU/ft2 Therefore, (Watt-hr m-2) (3.687 / 11.622) = BTU/ft2 or:

(Watt-hr m-2) (0.3172) = BTU/ft2 The program assumes that the radiation energy flux is constant during the entire hour, so the final equation is as follows:

(Watt-hr m-2) (0.3172) = BTU/(ft2 hr)

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B16 of B47 Figure 2 through Figure 5 present comparisons of program output predictions of solar radiation with NOAA measurements of solar radiation. Predictions and measurements are for Madison, Wisconsin during the following days: 25 January 1988, 28 July 1988, 30 July 1988, and 15 September 1988. The NOAA measurements were converted to the same numerical units as the program predictions, using the conversion factor described above.

The comparisons of estimated to measured solar radiation in Figure 2 through Figure 5 demonstrated that the solar radiation algorithm performs reasonably well and results are consistent with expectations. Those results validate the solar radiation algorithm.

Radiation prediction performance levels indicated by Figure 3 for 28 July 1988 and Figure 4 for 30 July 1988 are particularly good. As shown by hourly meteorological observations listed in Table 13, 28 July 1988 was a perfectly clear day at Madison.

Column 10, titled CL COV, contains cloud cover information (tenths), and column 2, titled CEIL, contains cloud ceiling height information (feet). In contrast, as shown by hourly meteorological data listed in Table 14, 30 July 1988 included marked variation of cloud cover (column 10 in Table 14) from 2 tenths to 9 tenths between 6 am and 6 pm at Madison. Therefore, the program predicted the peak daily radiation level well on both cloudy and clear days.

On 25 January 1988 (Figure 2), the program conservatively over-predicted peak solar radiation by about 17 percent. That was during a day with snow on the ground, variable ceilings heights (column 2 in Table 12) and overcast (10/10) sky cover (column 10 in Table 12). On 15 September 1988 (Figure 5), the program over-predicted peak solar radiation by about 10 percent. Conditions on 15 September 1988 featured total overcast between 7 am and 6 pm (column 10 in Table 15). It is not obvious why program predictions were slightly less accurate during 25 January and 15 September. A possible explanation is that during those two days the cloud cover observation at the top of each hour may not have accounted effectively for cloud variations during that hour.

Predictions for 25 January 1988 were less accurate than for the other three days, but still remarkably good. It is possible that the snow cover algorithm (which is an approximation) added some finite uncertainty during that day only.

10.2.2 Atmospheric Radiation Reaching the Ground Surface - Validation To verify calculations of atmospheric longwave radiation, data for hour 5 of 25 March 1955 at Springfield Illinois were manually used in a calculation with the atmospheric radiation formula. Results were as follows.

R = [(1.16) (10) -13 / 24] [460 + 29]6 [1 + ((0.17) ( 1.0 2 ))] = 77.32 BTU/(ft2 hr)

Where:

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B17 of B47 Data for hour 5 of 25 March 1955 at Springfield, Illinois were as follows Dry bulb temperature = 29°F Cloud cover = 1.0 (ten tenths)

Table 19 presents a list of processed weather data created by the program, for Springfield, Illinois, for 25 March 1955. Column 14 of the list contains data labeled LWRAD, meaning longwave atmospheric radiation. Column 1 indicates hour of day. The manually calculated value of 77.32 BTU/(ft2 hr) exactly matches the program-calculated value for hour 5, validating the atmospheric radiation algorithm.

10.2.3 Freezing Precipitation Code - Validation On December 3, 1996 the Peoria, IL National Weather Service recorded snow from 5 am until 9 am local standard time (LST). A portion of the raw meteorological data file (NCDC (2005)) containing weather observations from Peoria for December 3, 1996 is shown in Figure 6. The precipitation type observed at 5 and 6 am (precipitation type code 40, encoded as 04000 in the data file) is circled in the figure. Referring to precipitation type codes in Table 8, a precipitation type code 40 corresponds to light snow.

SURGEN processed the raw meteorological data (Figure 6) and produced a LAKET-PC-compatible meteorological data input file which included binary freezing precipitation codes. As explained above, SURGEN sets the binary precipitation type variable to one (1) in a LAKET-PC-compatible meteorological data input file when one of the precipitation types in Table 8 is observed. A portion of the LAKET-PC-compatible meteorological data input file from SURGEN corresponding to Figure 6 is shown in Figure 7. Binary freezing precipitation codes in the 5 and 6 am hourly records are circled in Figure 7. Figure 7 shows that the precipitation codes were set to one (1) in both records, which is consistent with the light snow (precipitation code 40 from Table 8) observed at those times. SURGEN recognized the occurrence of freezing precipitation in the raw weather observations and correctly set the binary freezing precipitation codes in the LAKET-PC meteorological data input file to one (1).

10.2.4 Partial Pressure of Water Vapor - Validation The partial pressure of water vapor was manually computed using meteorological data.

On July 30, 1996 at 2 am LST, the Peoria, IL National Weather Service recorded a dry-bulb temperature of 70°F and a relative humidity of 94% (Figure 8). The partial pressure of water vapor at those conditions is computed manually below using the logic of the PVSF subroutine described above.

The dry bulb temperature x = 70°F so that T is defined as T = (70+459.688)/1.8 = 294.2711

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B18 of B47 Since T >= 273.16 K compute z as follows:

z = 373.16/T = 373.16/294.2711 = 1.26808 Terms P1, P2, P3, and P4 are computed using their definitions in Table 9 and Table 11 P1 = -7.90298 (z-1) = -7.90298 (1.26808 - 1) = -2.11865 P2 = 5.02808 log10 (z) = 5.02808 log10 (1.26808) = 0.51863 P3 = -1.3816 x 10-7 x (10 (11.344 (1-1/1.26808))-1) = -0.00003 P4 = 8.1328 x 10-3 x (10(-3.49149 (1.26808-1))-1) = -0.00719 The partial pressure of water vapor at saturation (VAPPR) is computed using Eq. 1 and the above definitions of P1, P2, P3, and P4:

VAPPR = 29.921 x 10 (P1+P2+P3+P4) = 0.73916 inches Hg.

At a relative humidity of 94%, the partial pressure of water vapor (e) is computed using the partial pressure of water vapor in saturated air and Eq. 2 as follows:

e = VAPPR x (RH/100) = 0.73916 *(94/100) = 0.69 inches Hg.

The results of the manual computation are compared with results from SURGEN as follows. A portion of the raw meteorological data file (NCDC (2005)) containing the observed dry-bulb temperature and humidity at 2 am July 30, 1996 (70°F and 94%

relative humidity) is shown in Figure 8. SURGEN processed this raw meteorological data file and computed the partial pressure of water vapor using the subroutine PVSF (Figure 1). The computed value was included as part of the LAKET-PC meteorological data input file. A portion the LAKET-PC meteorological data input file showing the input dry-bulb temperature (70°F), relative humidity (94%) and computed partial pressure of water vapor is shown in Figure 9. Figure 9 shows that the partial pressure of water vapor computed by SURGEN (0.69 inches Hg.) matches the manually computed value above (0.69 inches Hg.).

The manually computed partial pressure of water vapor and the value from SURGEN are compared with the vapor pressure published in standard reference (List (1951)). Figure 10 shows a portion of the saturation vapor pressure table from List (1951, page 356) for a dry-bulb temperature of 70.0°F. The value shown in Figure 10 (0.73916 inches Hg.)

applies to saturated air (100% relative humidity), so the value in Figure 10 must be multiplied by the observed relative humidity (94%) to obtain the partial pressure of water vapor. Multiplying this value by 94% produces a partial vapor pressure of water of 0.69 inches Hg. (0.73916 x.94 = 0.69), which matches the manually computed value above

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B19 of B47 and the value computed by the PVSF subroutine in SURGEN (Figure 9). The subroutine PVSF, as implemented in SURGEN, correctly computed the partial pressure of water vapor.

11.0 REFERENCES

11.1 American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc.

(ASHRAE), 1975. Subroutine PVSF listed in: Subroutine Algorithms for Heating and Cooling Loads to Determine Building Energy Requirements, Atlanta, GA.

11.2 Colbeck, S.C., 1980. Dynamics of Snow and Ice Masses, U.S. Army Cold Regions Research and Engineering Laboratory, pp. 349-390, Academic Press, New York City, New York.

11.3 Del Greco, S.A., N. Lott and collaborators, 2006. Surface Data Integration at NOAAs National Climatic Data Center: Data Format, Processing, QC and Product Generation.

National Climatic Data Center (NCDC). 86th AMS Annual Meeting, 29 January - 2 February 2006, Atlanta, Georgia. Available online at:

http://ams.confex.com/ams/pdfpapers/100500.pdf 11.4 Geiger, R., 1965. The Climate Near the Ground, pp. 218-219, Harvard University Press, Cambridge Massachusetts.

11.5 Hess, S.L., 1979. Introduction to Theoretical Meteorology. Reprint Edition. Robert E.

Krieger Publishing Company, Malabar, FL.

11.6 Huschke, R.E. (Ed.), 1980. Glossary of Meteorology, American Meteorological Society, Boston Massachusetts.

11.7 Iribarne, J.V. and Godson, W.L., 1981. Atmospheric Thermodynamics. Second Edition.

D. Reidel Publishing Company, Boston.

11.8 Jirka, G.H., M. Watanabe, K.H. Octavio, C.F. Cerco, D.R.F. Harleman, 1978.

Mathematical Predictive Models for Cooling Ponds and Cooling Lakes Part A: Model Development and Design Considerations, Department of Civil Engineering, School of Engineering, Massachusetts Institute of Technology, Cambridge Massachusetts.

11.9 List, R. J., 1951. Smithsonian Meteorological Tables. Sixth Revised Edition.

Smithsonian Institution Press, Washington, D.C.

11.10 Meyers, T.P. and R.F. Dale, 1983. Predicting Daily Insolation with Hourly Cloud Height and Coverage, American Meteorological Society, Boston Massachusetts, Journal of Climate and Applied Meteorology, Volume 22, pages 537-545, April 1983.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B20 of B47 11.11 National Climatic Data Center (NCDC), 1988(a), 1989(a). Local Climatological Data, Monthly Summary, Madison Wisconsin December, January, and February, 1988, published by NCDC, Asheville North Carolina.

11.12 National Climatic Data Center (NCDC), 1988(b). Solar Radiation Data, Environmental Information Series C-18, for Madison Wisconsin for Year 1988, published by NCDC, Asheville North Carolina.

11.13 National Climatic Data Center (NCDC), 1989(b), 1990, 1991, 1992. Local Climatological Data, Monthly Summary, Greater Peoria Airport (Peoria Illinois),

December, January, and February, winters of 1988-1989 through 1991-1992, published by NCDC, Asheville North Carolina.

11.14 National Climatic Data Center (NCDC), 2000. Data Documentation for Hourly Precipitation Data TD-3240, November 15, 2000. Published by NCDC, Asheville, NC.

11.15 National Climatic Data Center (NCDC), 2002. Data file anem_elev_inf referenced in Data Documentation for Data Set 6421 (DSI-6421) Enhanced hourly wind station data for the contiguous United States National Climatic Data Center, Asheville North Carolina. Website:

http://www.wcc.nrcs.usda.gov/ftpref/support/climate/wind_daily/td6421.pdf Accessed December, 2013.

11.16 National Climatic Data Center (NCDC), 2005. Data Documentation for Data Set 3280 (DSI-3280). May 4, 2005. Published by NCDC, Asheville, NC.

11.17 National Climatic Data Center (NCDC), 2006. Federal Climate Complex Data Documentation for Integrated Surface Data, August 25, 2006. Published by NCDC, Asheville, NC.

11.18 National Climatic Data Center (NCDC), 2012. Hourly Precipitation Data Documentation (text and.csv version), April, 2012. Available from:

ftp://ftp.ncdc.noaa.gov/pub/data/cdo/documentation/PRECIP_HLY_documentation.pdf Accessed December, 2013.

11.19 Sargent & Lundy (S&L), 1997. User Manual SURGEN Program. S&L Program Number: 03.7.470-2.0.

11.20 Sargent & Lundy (S&L), 2004. LAKET-PC, A One Dimensional Lake Thermal Prediction Program, S&L Program Number LAK 03.7.292-2.2, Revision 0, October 30, 2004, User Manual, S&L, Chicago IL.

11.21 Sargent & Lundy (S&L), 2014. Design Information Transmittal (DIT) DIT-BRW-2014-0022. Transmittal of Braidwood Meteorological Tower Data for time periods between January 1, 1990 and October 31, 2013. May 1, 2014.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B21 of B47 Figure 1. The FORTRAN subroutine PVSF from ASHRAE (1975).

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B22 of B47 Figure 2. Comparison of Program Predicted Solar Radiation with Solar Radiation Measurements from Madison Wisconsin during 25 January 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B23 of B47 Figure 3. Comparison of Program Predicted Solar Radiation with Measurements from Solar Radiation Madison Wisconsin during 28 July 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B24 of B47 Figure 4. Comparison of Program Predicted Solar Radiation with Solar Radiation Measurements from Madison Wisconsin during 30 July 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B25 of B47 Figure 5. Comparison of Program Predicted Solar Radiation with Solar Radiation Measurements from Madison Wisconsin during 15 September 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B26 of B47 Figure 6. A portion of the meteorological weather record for Peoria, IL for December 3, 1996. Portions of the records for 5 and 6 am LST are annotated.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B27 of B47 Figure 7. A portion of the LAKET-PC input file for 5 and 6 am LST December 3, 1996.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B28 of B47 Figure 8. A portion of the meteorological weather record for Peoria, IL for July 30, 1996.

Portions of the 2 am LST record are annotated.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B29 of B47 Figure 9. A portion of the LAKET-PC input file for 2 am LST July 30, 1996.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B30 of B47 Figure 10. A portion of the saturation vapor pressure table from List (1951, page 356).

The entry corresponding to a dry-bulb temperature of 70.0°F is annotated.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B31 of B47 Table 1. Parameters and Digital Record Format of the Standard Weather Data File Used by S&Ls LAKET-PC Program Field No.

Parameter Units Lower Limit Upper Limit FORTRAN Format Specifier 1

Station Code Number (5 digits)

F7.0 2

Year (4 digits)

F6.0 3

Month F4.0 4

Day F4.0 5

Hour of Day

[00 (midnight)-23 (11 pm)]

F9.2 6

Cloud Ceiling Height above Ground Level feet 0

70,000 F9.2 7

Direction Sector from which Wind Blows [1(N) -

16(NNW)]

1 16 F9.2 8

Wind speed Knots 0

96 F9.2 9

Dry Bulb Temperature deg F

-129 136 F9.2 10 Wet Bulb Temperature deg F

-129 136 F9.2 11 Dew Point Temperature deg F

-129 136 F9.2 12 Relative Humidity percent 0

100 F9.2 13 Station Atmospheric Pressure inches Hg 25.69 32.01 F9.2 14 Cloud Cover Tenths 00 10 F9.2 15 Freezing Precipitation Code 0

1 F9.2 16 One-Hour Total Liquid Equivalent Precipitation 100ths inches 0

1,200 F9.2 17 Solar Radiation BTU/ft2-hour 0

4,000 F9.2 18 Atmospheric Radiation BTU/ft2-hour 5

220 F9.2 19 Partial Pressure of Water Vapor inches Hg 0 2.00 F9.2

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B32 of B47 Table 2. Primary and Secondary Data Sources Beginning Date Ending Date Parameter Primary Data Source Secondary Data Source July 5, 1948 December 31, 1951 All parameters NWS-Peoria (KPIA)

None January 1, 1952 December 31, 1956 All parameters NWS-Springfield (KSPI)

None January 1, 1957 December 31, 1989 All parameters NWS-Peoria (KPIA)

None January 1, 1990 December 31, 2012 Dry bulb temperature, dew point temperature, wind speed, wind direction On-site meteorological tower NWS-Peoria (KPIA)

January 1, 1990 December 31, 2012 Cloud cover, cloud height, precipitation

type, precipitation NWS-Peoria (KPIA)

None Table 3. On-site Meteorological Tower Wind and Temperature Instrumentation Parameter Height (feet)

Dry bulb temperature 30 Dew point temperature 30 Wind speed/direction 34 Sigma theta 34 Dry bulb temperature 199 Delta-T (vertical temperature difference) 30 - 199 Wind speed/direction 203 Sigma theta 203

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B33 of B47 Table 4. Missing Parameters from the On-site Tower and Substituted Parameters (DB = dry bulb temperature, DP = dew point temperature, WD = wind direction, WS = wind speed)

Beginning time Ending time Date Hour (LST)

Date Hour (LST)

Duration (hours)

Parameters Missing from the On-site Tower Data Set Parameters Substituted from NWS-Peoria 2/7/1990 7

2/7/1990 14 8

WS WS,WD 5/30/1990 11 5/30/1990 16 6

DB DB 10/18/1990 7

10/18/1990 14 8

DP DP 10/20/1990 11 10/20/1990 18 8

DP DP 10/22/1990 12 10/22/1990 18 7

DP DP 10/23/1990 8

10/23/1990 23 16 DP DP 12/21/1990 22 12/24/1990 3

54 WD WS,WD 12/30/1990 11 12/31/1990 16 30 DP DP 3/14/1991 19 3/15/1991 10 16 WS WS,WD 3/30/1991 1

3/30/1991 13 13 WD WS,WD 4/19/1991 8

4/21/1991 22 63 WD WS,WD 5/1/1991 15 5/1/1991 24 10 WD WS,WD 5/2/1991 9

5/3/1991 6

22 WD WS,WD 5/3/1991 17 5/4/1991 9

17 WD WS,WD 5/25/1991 16 5/26/1991 10 19 WS WS,WD 6/22/1991 7

6/23/1991 5

23 WD WS,WD 8/2/1991 17 8/2/1991 24 8

DP DP 8/8/1991 17 8/12/1991 21 101 WD WS,WD 12/19/1992 23 12/20/1992 11 13 WS WS,WD 8/30/1993 23 9/1/1993 9

35 WS WS,WD 11/26/1993 9

11/27/1993 5

21 WS,WD WS,WD 6/9/1994 20 6/10/1994 7

12 WS WS,WD 7/7/1994 17 7/8/1994 8

16 WS WS,WD 10/8/1997 11 10/9/1997 6

20 WS,WD,DB,DP WS,WD,DB,DP 10/10/1998 3

10/10/1998 9

7 WS,WD WS, WD 11/10/1998 5

11/10/1998 13 9

WS,WD WS, WD 1/8/1999 2

1/8/1999 8

7 DP DP 3/4/1999 2

3/4/1999 11 10 DP DP 1/28/2000 6

1/28/2000 13 8

DP DP 2/7/2000 23 2/8/2000 9

11 WS WS, WD 5/20/2000 23 5/24/2000 9

83 WS WS, WD 4/20/2001 2

4/23/2001 10 81 DP DP 4/21/2001 5

4/22/2001 10 30 WS WS, WD

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B34 of B47 Table 4. Missing Parameters from the On-site Tower and Substituted Parameters (DB = dry bulb temperature, DP = dew point temperature, WD = wind direction, WS = wind speed)

Beginning time Ending time Date Hour (LST)

Date Hour (LST)

Duration (hours)

Parameters Missing from the On-site Tower Data Set Parameters Substituted from NWS-Peoria 7/8/2001 15 7/9/2001 9

19 WS WS, WD 10/23/2001 3

10/26/2001 12 82 WD WS, WD 1/31/2002 21 2/1/2002 5

9 WS, WD WS, WD 2/19/2002 3

2/28/2002 14 228 DP DP 9/3/2002 0

9/4/2002 6

7 WS WS, WD 9/4/2002 19 9/5/2002 5

11 WS WS, WD 9/8/2002 20 9/9/2002 8

13 WS WS, WD 9/11/2002 21 9/12/2002 8

12 WS WS, WD 9/12/2002 18 9/13/2002 7

14 WS WS, WD 9/16/2002 18 9/17/2002 8

15 WS WS, WD 7/6/2003 14 7/6/2003 22 9

DP DP 7/8/2003 14 7/8/2003 20 7

DP DP 7/11/2003 15 7/11/2003 23 9

DP DP 7/12/2003 21 7/13/2003 6

10 DP DP 7/13/2003 20 7/14/2003 6

11 DP DP 7/15/2003 4

7/15/2003 11 8

DP DP 7/15/2003 23 7/16/2003 9

11 DP DP 7/19/2003 19 7/20/2003 1

7 DP DP 7/23/2003 21 7/24/2003 9

13 DP DP 11/14/2003 16 11/15/2003 14 29 DP DP 11/14/2003 10 11/14/2003 15 6

WS,WD,DB,DP WS,WD,DB,DP 1/4/2004 9

1/4/2004 20 12 DP DP 5/30/2004 7

5/30/2004 21 15 DP DP 9/16/2004 15 9/17/2004 1

11 WS,WD,DB,DP WS,WD,DB,DP 11/16/2004 5

11/16/2004 14 10 WS,WD,DB,DP WS,WD,DB,DP 1/13/2005 7

1/14/2005 6

24 WS,WD,DB,DP WS,WD,DB,DP 2/24/2005 15 2/24/2005 23 9

WS WS, WD 5/14/2006 19 5/16/2006 8

38 WD WS, WD 8/23/2007 15 8/23/2007 22 8

WS,WD,DB,DP WS,WD,DB,DP 1/7/2008 22 1/8/2008 13 16 WS,WD,DB,DP WS,WD,DB,DP 12/19/2008 2

12/21/2008 7

54 WS WS,WD 11/21/2009 16 11/22/2009 8

17 WS,WD,DB,DP WS,WD,DB,DP 3/7/2011 19 3/8/2011 12 18 WD WS, WD 11/9/2011 5

11/9/2011 13 9

WD WS, WD

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B35 of B47 Table 4. Missing Parameters from the On-site Tower and Substituted Parameters (DB = dry bulb temperature, DP = dew point temperature, WD = wind direction, WS = wind speed)

Beginning time Ending time Date Hour (LST)

Date Hour (LST)

Duration (hours)

Parameters Missing from the On-site Tower Data Set Parameters Substituted from NWS-Peoria 11/13/2012 6

11/14/2012 13 32 WS,WD,DB,DP WS,WD,DB,DP 11/23/2012 10 11/24/2012 9

24 WD WS, WD

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B36 of B47 Table 5. Historical Wind Sensor Height Input for LAKET-PC Beginning Date Ending Date Sensor Height (feet)

Primary Wind Data Source 7/5/1948 11/21/1948 26 NWS-Peoria (KPIA) 11/22/1948 12/31/1951 50 NWS-Peoria (KPIA) 1/1/1952 12/31/1956 49 NWS-Springfield (KSPI) 1/1/1957 9/30/1959 50 NWS-Peoria (KPIA) 10/1/1959 12/31/1989 20 NWS-Peoria (KPIA) (Note 1) 1/1/1990 12/31/2012 34 On-site meteorological tower (Note 2)

Note 1: The anemometer height at NWS-Peoria was 20 feet through 9/30/1995.

Starting on 10/1/1995, the anemometer height at NWS-Peoria was increased to its current height of 32.8 feet.

Note 2: The wind sensor height in LAKET-PC is 34 feet which is the anemometer height of the lowest wind speed level of the on-site tower.

Table 6. Snow and Temperature Data from Peoria Illinois Used to Construct a Snow Accumulation Algorithm Maximum final snow depth on ground (inches)

Total period water equivalent precipitation (inches)

Date Maximum air temperature during time of precipitation

(°F)

Final snow depth to liquid water ratio 3

0.68 27 Dec 1988 29 4.4 4

0.17 4 Feb 1989 3

23.5 5

0.31 20 Feb 1989 31 16.1 6

0.36 10 Dec 1989 31 16.7 4

1.02 25 Jan 1990 36 3.3 3

1.06 22 Feb 1990 32 2.8 4

0.20 15 Jan 1992 22 20.0 5

0.64 5 Jan 1991 24 9.4

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B37 of B47 Table 7. Snow and Temperature Data from Madison Wisconsin Used to Construct a Snow Melt Algorithm Air temp

(°F)

Snow depth increase (inches per hour)

Air temp

(°F)

Snow depth increase (inches per hour)

Air temp

(°F)

Snow depth increase (inches per hour)

-2 0.000 16 0.021 35 0.083

-1 0.000 17 0.021 36 0.166 0

0.000 18 0.021 37 0.166 1

0.000 19 0.042 38 0.166 2

0.000 20 0.042 39 0.166 3

0.000 21 0.042 40 0.166 4

0.000 22 0.042 41 0.333 5

0.000 23 0.042 42 0.333 6

0.000 24 0.042 43 0.333 7

0.000 25 0.042 44 0.333 8

0.000 26 0.042 45 0.333 9

0.000 27 0.042 46 0.333 10 0.021 28 0.042 47 0.667 11 0.021 29 0.042 48 0.667 12 0.021 30 0.042 49 0.667 13 0.021 31 0.042 50 0.667 14 0.021 32 0.083 51 0.667 15 0.021 33 0.083 52 0.667 34 0.083

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B38 of B47 Table 8. Precipitation Type Codes Used in Surface Weather Observations (Source:

NCDC 2005)

Precipitation code Precipitation description Precipitation code Precipitation description 26 light freezing rain 54 moderate snow squall (Note 3) 27 moderate freezing rain 55 heavy snow squall (Note 3) 28 heavy freezing rain 56 light snow grains 36 light freezing drizzle 57 moderate snow grains 37 moderate freezing drizzle 58 heavy snow grains 38 heavy freezing drizzle 60 light ice pellet showers 40 light snow 61 moderate ice pellet showers 41 moderate snow 62 heavy ice pellet showers 42 heavy snow 63 light hail 43 light snow pellets (Note 1) 64 moderate hail (Note 4) 44 moderate snow pellets (Note 1) 65 heavy hail (Note 4) 45 heavy snow pellets (Note

1) 66 light small hail (Note 4) 46 light ice crystals (Note 2) 67 moderate small hail (Note

4) 47 moderate ice crystals 68 heavy small hail (Note 4) 48 heavy ice crystals (Note 2) 90 light ice pellets 50 light snow showers 91 moderate ice pellets 51 moderate snow showers 92 heavy ice pellets 52 heavy snow showers 93 hail showers (Note 5) 53 light snow squall (Note 3) 94 small hail/snow pellet showers (Note 5)

Note 1: Codes 43, 44, and 45 ended in June, 1996 and replaced with code 67.

Note 2: Code replaced with 47 in April, 1963.

Note 3: Code used through 1948.

Note 4: Prior to April, 1970 ice pellets were coded as sleet. Beginning April, 1970 sleet and small hail were redefined as ice pellets and are coded as 60, 61, or 62. Beginning in September, 1956 intensities of hail were no longer reported and all occurrences of hail were recorded as a 64. Beginning July, 1996 hail was defined as hailstones 1/4 inch or larger in diameter; small hail and snow pellets are reported when less than 1/4 inch in diameter and are coded as 64 and 67, respectively.

Note 5: Began July, 1996.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B39 of B47 Table 9. Constants used in vapor pressure equation (Source: ASHRAE (1975))

Constant Value Constant Value A1

-7.90298 B1

-9.09718 A2 5.02808 B2

-3.56654 A3

-1.3816 x 10-7 B3 0.876793 A4 11.344 B4 0.0060273 A5 8.1328 x 10-3 A6

-3.49149 Table 10. Constants used in vapor pressure equation for T < 273.16 K (Source:

ASHRAE (1975))

Parameter Definition P1

)1

(

1

z B

P2

)

(

log 2

10 z B

P3

)

/

1 1(

3 z

B

P4

)

4

(

log10 B Table 11. Constants used in vapor pressure equation for T >= 273.16 K)

(Source: ASHRAE (1975))

Parameter Definition P1

)1

(

1

z A

P2

)

(

log 2

10 z A

P3

)1 10

(

3

))

/

1 1

(

4

(

z A

A P4

)1 10

(

5

))

1

(

6

(

z A

A

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B40 of B47 Table 12. Program Output Listing of Processed Meteorological Data from Madison Wisconsin for 25 January 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B41 of B47 Table 13. Program Output Listing of Processed Meteorological Data from Madison Wisconsin for 28 July 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B42 of B47 Table 14. Program Output Listing of Processed Meteorological Data from Madison Wisconsin for 30 July 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B43 of B47 Table 15. Program Output Listing of Processed Meteorological Data from Madison Wisconsin for 15 September 1988

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B44 of B47 Table 16. NOAA January 1988 Madison Wisconsin Solar Radiation Measurements

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B45 of B47 Table 17. NOAA July 1988 Madison Wisconsin Solar Radiation Measurements

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B46 of B47 Table 18. NOAA September 1988 Madison Wisconsin Solar Radiation Measurements

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT B, PAGE B47 of B47 Table 19. Program Output Listing of Processed Meteorological Data from Springfield Illinois for 25 March 1955

Calculation No. ATD-0109, Rev. 4 Attachment C Page C1 of C4 Table C1: Determination of 3 Hour Average Heat Loads For First 24 Hours Time Time Total Heat Load Trapezoidal Rule Sum of Average (hours)

(seconds) to the UHS Integration Over Previous Column Heat Load Over (Worst Case from ATD-0063, page E9, Table 13 )

Previous Time Step Over Time Interval Time Interval (Btu/Hr)

(Btu-sec/hr)

(Btu/hr) 0 0.0000E+00 0

1.0000E+01 8.30E+07 4.15E+08 2.0000E+01 8.30E+07 8.30E+08 2.1000E+01 5.85E+08 3.34E+08 3.3000E+01 5.75E+08 6.96E+09 5.0000E+01 5.68E+08 9.72E+09 1.0200E+02 5.54E+08 2.92E+10 1.3100E+02 5.47E+08 1.60E+10 1.9900E+02 5.33E+08 3.67E+10 2.8900E+02 5.22E+08 4.75E+10 3.4900E+02 5.17E+08 3.12E+10 4.5900E+02 5.08E+08 5.64E+10 5.9900E+02 4.99E+08 7.05E+10 6.9500E+02 4.94E+08 4.77E+10 6.9500E+02 7.87E+08 7.69E+05 8.9900E+02 7.93E+08 1.61E+11 9.9900E+02 7.96E+08 7.95E+10 1.0990E+03 7.95E+08 7.96E+10 1.1990E+03 7.86E+08 7.91E+10 1.2990E+03 7.77E+08 7.82E+10 1.3990E+03 7.68E+08 7.73E+10 1.7640E+03 7.34E+08 2.74E+11 2.2990E+03 6.35E+08 3.66E+11 2.8990E+03 5.60E+08 3.59E+11 3.5990E+03 5.19E+08 3.78E+11 4.9990E+03 4.58E+08 6.84E+11 6.9990E+03 3.79E+08 8.37E+11 9.9990E+03 3.32E+08 1.07E+12 3

1.0800E+04 3.27E+08 2.64E+11 5.14E+12 4.76E+08 1.9999E+04 2.67E+08 2.73E+12 6

2.1600E+04 2.67E+08 4.27E+11 3.16E+12 2.92E+08 2.9998E+04 2.67E+08 2.24E+12 2.9999E+04 5.51E+08 4.09E+08 9

3.2400E+04 5.34E+08 1.30E+12 3.55E+12 3.28E+08 3.9999E+04 4.80E+08 3.85E+12 12 4.3200E+04 4.34E+08 1.46E+12 5.32E+12 4.92E+08 4.9999E+04 3.36E+08 2.62E+12 15 5.4000E+04 3.33E+08 1.34E+12 3.96E+12 3.66E+08 5.9999E+04 3.28E+08 1.98E+12 18 6.4800E+04 3.24E+08 1.57E+12 3.55E+12 3.28E+08 21 7.5600E+04 3.16E+08 3.45E+12 3.45E+12 3.20E+08 7.9999E+04 3.12E+08 1.38E+12 24 8.6400E+04 3.07E+08 1.98E+12 3.36E+12 3.11E+08 8.9999E+04 3.04E+08 1.10E+12

Calculation No. ATD-0109, Rev. 4 Attachment C Page C2 of C4 Table C2: Determination of Plant Temperature Rise For First 24 Hours Time Ave T

T T

Heat Load 2 Pumps 3 Pumps 4 Pumps (hours)

(Btu/hr)

(oF)

(oF) 0 - 3 4.76E+08 19.793 14.846 9.896 Flowrates 3 - 6 2.92E+08 12.173 9.131 6.087 lbm/hr 6 - 9 3.28E+08 13.66 10.25 6.832 2 Pumps 24025000 9 - 12 4.92E+08 20.49 15.37 10.243 3 Pumps 32030000 12 - 15 3.66E+08 15.25 11.44 7.623 4 Pumps 48050000 15 - 18 3.28E+08 13.67 10.254 6.835 18 - 21 3.20E+08 13.31 9.986 6.656 Cp 1

(Btu/hr-lbm-oF) 21 - 24 3.11E+08 12.95 9.715 6.476 Table C3: Determination of Plant Temperature Rise For 24 To 2160 Hours Time Heat Load T

T T

2 Pumps 3 Pumps 4 Pumps (seconds)

(hours)

(Btu/hr)

(oF)

(oF) 8.64E+04 24.00 3.07E+08 12.761 9.572 6.381 9.00E+04 25.00 3.04E+08 12.637 9.479 6.318 1.00E+05 27.78 2.96E+08 12.337 9.254 6.169 8.00E+05 222.22 2.23E+08 9.274 6.956 4.637 7.78E+06 2160.00 2.23E+08 9.274 6.956 4.637 Assumed Constant

Calculation No. ATD-0109, Rev. 4 Attachment C Page C3 of C4 1

2 3

4 5

6 7

8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 A

B C

D E

F Time Time Total Heat Load Trapezoidal Rule Sum of Average (hours)

(seconds) to the UHS Integration Over Previous Column Heat Load Over (Worst Case from ATD-0063, page E9, Table 13 )

Previous Time Step Over Time Interval Time Interval (Btu/Hr)

(Btu-sec/hr)

(Btu/hr) 0 0

0 10 83000000

=(B8-B7)*(C8+C7)/2 20 83000000

=(B9-B8)*(C9+C8)/2 21 585000000

=(B10-B9)*(C10+C9)/2 33 575000000

=(B11-B10)*(C11+C10)/2 50 568000000

=(B12-B11)*(C12+C11)/2 102 554000000

=(B13-B12)*(C13+C12)/2 131 547000000

=(B14-B13)*(C14+C13)/2 199 533000000

=(B15-B14)*(C15+C14)/2 289 522000000

=(B16-B15)*(C16+C15)/2 349 517000000

=(B17-B16)*(C17+C16)/2 459 508000000

=(B18-B17)*(C18+C17)/2 599 499000000

=(B19-B18)*(C19+C18)/2 695 494000000

=(B20-B19)*(C20+C19)/2 695.0012 787000000

=(B21-B20)*(C21+C20)/2 899 793000000

=(B22-B21)*(C22+C21)/2 999 796000000

=(B23-B22)*(C23+C22)/2 1099 795000000

=(B24-B23)*(C24+C23)/2 1199 786000000

=(B25-B24)*(C25+C24)/2 1299 777000000

=(B26-B25)*(C26+C25)/2 1399 768000000

=(B27-B26)*(C27+C26)/2 1764 734000000

=(B28-B27)*(C28+C27)/2 2299 635000000

=(B29-B28)*(C29+C28)/2 2899 560000000

=(B30-B29)*(C30+C29)/2 3599 519000000

=(B31-B30)*(C31+C30)/2 4999 458000000

=(B32-B31)*(C32+C31)/2 6999 379000000

=(B33-B32)*(C33+C32)/2 9999 332000000

=(B34-B33)*(C34+C33)/2

=B35/3600 10800

=(B35-B34)/(B36-B34)*(C36-C34)+C34

=(B35-B34)*(C35+C34)/2

=SUM(D8:D35)

=E35/10800 19999 267000000

=(B36-B35)*(C36+C35)/2

=B37/3600 21600 267000000

=(B37-B36)*(C37+C36)/2

=SUM(D36:D37)

=E37/10800 29998 267000000

=(B38-B37)*(C38+C37)/2 29999 551000000

=(B39-B38)*(C39+C38)/2

=B40/3600 32400

=(B40-B39)/(B41-B39)*(C41-C39)+C39

=(B40-B39)*(C40+C39)/2

=SUM(D38:D40)

=E40/10800 39999 480000000

=(B41-B40)*(C41+C40)/2

=B42/3600 43200

=(B42-B41)/(B43-B41)*(C43-C41)+C41

=(B42-B41)*(C42+C41)/2

=SUM(D41:D42)

=E42/10800 49999 336100000

=(B43-B42)*(C43+C42)/2

=B44/3600 54000

=(B44-B43)/(B45-B43)*(C45-C43)+C43

=(B44-B43)*(C44+C43)/2

=SUM(D43:D44)

=E44/10800 59999 327900000

=(B45-B44)*(C45+C44)/2

=B46/3600 64800

=(B46-B45)/(B48-B45)*(C48-C45)+C45

=(B46-B45)*(C46+C45)/2

=SUM(D45:D46)

=E46/10800

=B47/3600 75600

=(B47-B45)/(B48-B45)*(C48-C45)+C45

=(B47-B46)*(C47+C46)/2

=SUM(D47)

=E47/10800 79999 312100000

=(B48-B47)*(C48+C47)/2

=B49/3600 86400

=(B49-B47)/(B50-B47)*(C50-C47)+C47

=(B49-B48)*(C49+C48)/2

=SUM(D48:D49)

=E49/10800 89999 303600000

=(B50-B49)*(C50+C49)/2 Formulas for Table C1

Calculation No. ATD-0109, Rev. 4 Attachment C Page C4 of C4 1

2 3

4 5

6 7

8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 A

B C

D E

F G

H Time Ave T

T T

Heat Load 2 Pumps 3 Pumps 4 Pumps (hours)

(Btu/hr)

(oF)

(oF) 0 - 3

=AVE_HL!F35

=$B6/($G$8*$G$12)

=$B6/($G$9*$G$12)

=$B6/($G$10*$G$12)

Flowrates 3 - 6

=AVE_HL!F37

=$B7/($G$8*$G$12)

=$B7/($G$9*$G$12)

=$B7/($G$10*$G$12) lbm/hr 6 - 9

=AVE_HL!F40

=$B8/($G$8*$G$12)

=$B8/($G$9*$G$12)

=$B8/($G$10*$G$12) 2 Pumps 24025000 9 - 12

=AVE_HL!F42

=$B9/($G$8*$G$12)

=$B9/($G$9*$G$12)

=$B9/($G$10*$G$12) 3 Pumps 32030000 12 - 15

=AVE_HL!F44

=$B10/($G$8*$G$12)

=$B10/($G$9*$G$12)

=$B10/($G$10*$G$12) 4 Pumps 48050000 15 - 18

=AVE_HL!F46

=$B11/($G$8*$G$12)

=$B11/($G$9*$G$12)

=$B11/($G$10*$G$12) 18 - 21

=AVE_HL!F47

=$B12/($G$8*$G$12)

=$B12/($G$9*$G$12)

=$B12/($G$10*$G$12)

Cp 1

(Btu/hr-lbm-oF) 21 - 24

=AVE_HL!F49

=$B13/($G$8*$G$12)

=$B13/($G$9*$G$12)

=$B13/($G$10*$G$12)

Time Heat Load T

T T

2 Pumps 3 Pumps 4 Pumps (seconds)

(hours)

(Btu/hr)

(oF)

(oF) 86400

=A21/3600

=AVE_HL!C49

=$C21/($G$8*$G$12)

=$C21/($G$9*$G$12)

=$C21/($G$10*$G$12) 89999

=A22/3600 303600000

=$C22/($G$8*$G$12)

=$C22/($G$9*$G$12)

=$C22/($G$10*$G$12) 99999

=A23/3600 296400000

=$C23/($G$8*$G$12)

=$C23/($G$9*$G$12)

=$C23/($G$10*$G$12) 799999

=A24/3600 222800000

=$C24/($G$8*$G$12)

=$C24/($G$9*$G$12)

=$C24/($G$10*$G$12) 7776000

=A25/3600 222800000

=$C25/($G$8*$G$12)

=$C25/($G$9*$G$12)

=$C25/($G$10*$G$12)

Assumed Constant Formuilas for Table C2 Formulas for Table C3

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT D, PAGE D1 of D4 Attachment D MES-11.1 Stratification Review

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT D, PAGE D2 of D4 Purpose The purpose of this attachment is to verify the applicability of LAKET-PC computer program to Braidwood UHS. This is done by review of UHS stratification as presented in Sargent & Lundy standard MES-11.1. Since LAKET-PC uses a one-dimensional thermal prediction model, a stratification check confirms applicability of using the plug-flow model utilized by LAKET-PC computer program to evaluate Braidwood UHS.

Methodology A method for determining if a lake is stratified is presented in Sargent & Lundy standard MES-11.1. This method consists of assuming the lake is stratified with the less dense hot water floating on top of the slightly more dense colder water. If the calculated value for the upper layer depth is close to or beneath the actual lake bottom, then the lake can be regarded as not stratified. The depth of the upper layer hot water is determined using Eq.

1.

4

/

1 2

3 2

4

TB g

L D

Q f

h s

i u

(Eq. 1)

Where:

fi - Interfacial shear coefficient, estimated as one-half of bottom friction coefficient fi = 0.5

8

g / Cz 2

(Eq. 2)

Cz - Chezy coefficient Cz = 1.47

H1/6 / n (Eq. 3)

H - lake depth (ft) n - Manning roughness coefficient - The Manning coefficient is assumed to be 0.02.

This is an approximate, conservatively low value [Ref. 5.16, Table 3.3.17] based on the surface of crushed stone bedding, or earth.

Q - Circulating water flow (ft3/s)

Ds - Dilution ratio (total lake flow / circulating water flow)

L - Lake length (ft) g - gravity (ft/s2)

- Bulk expansion coefficient of water (°F)

= 4.1x10-6 * (Tave - 39)

(Eq. 4)

Tave-Average temperature of discharge and receiving water temperature (°F)

T - Temperature difference between upper and lower levels (°F)

B - Width of lake (ft)

For the case where a jet or plume is formed in the lake, the dilution ratio (Ds) is found from the following steps.

T g

h U

Fr d

d

/

(Eq. 5)

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT D, PAGE D3 of D4 Fr b

h b

h h

d d

4

/

1 max

)

/

(

42

.0

(Eq. 6) 4

/

1 2

)

/

(

1 4.1 d

d s

b h

Fr D

(Eq. 7)

Where:

Fr - discharge Froude number Ud - Velocity at discharge structure (ft/s) hd - Depth of discharge structure (ft) bd - 1/2 width of discharge structure (ft)

Ds

- Dilution ratio without correction for lake bottom If the maximum depth of the plume (hmax) is greater than the depth of the lake, a correction factor is applied to the dilution ratio.

4

/

3 max )

/

75

.0

(

h H

r (Eq. 8) s s

rD D

(Eq. 9)

Where:

r -

Dilution correction factor The upper layer depth (hu) is used to determine the degree of stratification in the lake. If the volume of the lake below the upper layer depth is small compared to the total volume of the lake, then a plug flow model such as LAKET should be valid. When the volume below the upper layer depth is greater than one half the total volume of the lake, a different model that accounts for stratification should be used.

Evaluation The calculation of the upper layer depth was done for the UHS at Braidwood in order to determine the degree of stratification. The following table shows the calculation of the upper layer depth, which is done according to the methodology presented in the previous section. This calculation is done for varying number of operating SX pumps to match the cases evaluated in the main body of the calculation. The temperature difference between the upper and lower layers is calculated as the difference between the plant outlet temperature and the initial UHS temperature of 102°F. Note that only hot summer conditions (102°F) are considered since this it the time the highest UHS temperatures are expected.

CALCULATION NO. ATD-0109 REVISION NO. 4 ATTACHMENT D, PAGE D4 of D4 Table 1: Calculation of Upper Layer Depth Parameter Symbol Units 2 SX Pumps 3 SX Pumps 4 SX Pumps Basis Gross Lake Area A

Acres 95.6 95.6 95.6 ATD-0109 Gross Lake Volume V

Acre-ft 555.8 555.8 555.8 ATD-0109 Average Depth H

ft 5.81 5.81 5.81

= V / A Flow Rate Q

cfs 106.94 142.59 213.89 ATD-0109 Plant Inlet Temperature Ti

°F 102 102 102 ATD-0109 Temperature Rise through Plant Tp

°F 9.5 7.1 4.7 ATD-0109 Lake Length L

ft 3076 3076 3076 ATD-0109 Lake Width B

ft 1354 1354 1354

= A

43650 / L Width of Discharge Structure Bd ft 7.1 7.1 7.1 2x48" pipes [Ref. 5.15]

Depth of Discharge Structure hd ft 3.5 3.5 3.5 2x48" pipes [Ref. 5.15]

Discharge Velocity Vd ft/s 4.255 5.673 8.510

= Q / (Bd

hd)

Assumed Lake Temp T

°F 102 102 102 ATD-0109 Assumed Manning Roughness Coeff.

n

(-)

0.02 0.02 0.02 10th Ed., Marks' Handbook, Table 3.3.17 [Ref. 5.16]

Bulk Expansion Coefficient

°F 2.58E-04 2.58E-04 2.58E-04 Eq. 4 Discharge Froude Number Fr

(-)

8.05 12.39 22.76 Eq. 5 Maximum Plume Depth hmax ft 11.98 18.44 33.89 Eq. 6 Dilution ratio (uncorrected)

Ds*

(-)

11.35 17.40 31.89 Eq. 7 Dilution Ratio Correction Factor r

(-)

0.47 0.34 0.21 Eq. 8 Dilution Ratio (corrected)

Ds

(-)

5.32 5.90 6.85 Eq. 9 Chezy's Coefficient Cz

(-)

98.56 98.56 98.56 Eq. 3 Interfacial Friction Coefficient fi

(-)

0.013 0.013 0.013 Eq. 2 Upper Layer Depth hu ft 3.32 4.45 6.75 Eq. 1 Gross Volume V

Acre-ft 555.8 555.8 555.8 ATD-0109 Volume Below Upper Layer Vb Acre-ft 246.9 142.2 0.0 Interpolation of volume curve in ATD-Fraction of Lake Volume Below hu

(-)

0.44 0.26 0.00

= Vb / V Test for Lake Stratification Conclusion As seen in Table 1, the most conservative calculated upper layer depth for the Braidwood UHS is 3.32 ft, which occurs with 2 SX pumps in operation. Using this depth, the fraction of the UHS below the upper layer depth is 44%. According to MES-11.1, LAKET is applicable to a certain lake if this fraction is less than 50%. Therefore, LAKET is acceptable for analyzing the Braidwood UHS.

Calculation No. ATD-0109, Rev. 4 Attachment E Page E1 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Plant Inlet Temp (°F) 12AM 3AM 6AM 9AM 12PM 3PM 6PM 9PM

Calculation No. ATD-0109, Rev. 4 Attachment E Page E2 of E33 Maximum UHS Temperature - 2 SX Pumps - 33 days 86 88 90 92 94 96 98 100 102 104 106 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Days Plant Inlet Temp (°F) 12AM 3AM 6AM 9AM 12PM 3PM 6PM 9PM

Calculation No. ATD-0109, Rev. 4 Attachment E Page E3 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 12 AM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E4 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 3AM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E5 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 6AM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E6 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 9AM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E7 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 12PM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E8 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 3PM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E9 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 6PM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E10 of E33 Maximum UHS Temperature - 2 SX Pumps - 5 Days - 9PM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E11 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Plant Inlet Temp (°F) 12AM 3AM 6AM 9AM 12PM 3PM 6PM 9PM

Calculation No. ATD-0109, Rev. 4 Attachment E Page E12 of E33 Maximum UHS Temperature - 3 SX Pumps - 33 Days 88 90 92 94 96 98 100 102 104 106 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Days Plant Inlet Temp (°F) 12AM 3AM 6AM 9AM 12PM 3PM 6PM 9PM

Calculation No. ATD-0109, Rev. 4 Attachment E Page E13 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 12AM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E14 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 3AM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E15 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 6AM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E16 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 9AM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E17 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 12PM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E18 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 3PM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E19 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 6PM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E20 of E33 Maximum UHS Temperature - 3 SX Pumps - 5 Days - 9PM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E21 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days 92 94 96 98 100 102 104 106 108 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Plant Inlet Temp (°F) 12AM 3AM 6AM 9AM 12PM 3PM 6PM 9PM

Calculation No. ATD-0109, Rev. 4 Attachment E Page E22 of E33 Maximum UHS Temperature - 4 SX Pumps - 32 Days 88 90 92 94 96 98 100 102 104 106 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Days Plant Inlet Temp (°F) 12AM 3AM 6AM 9AM 12PM 3PM 6PM 9PM

Calculation No. ATD-0109, Rev. 4 Attachment E Page E23 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 12AM Start 92 94 96 98 100 102 104 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E24 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 3AM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E25 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 6AM Start 92 94 96 98 100 102 104 106 108 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E26 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 9AM Start 92 94 96 98 100 102 104 106 108 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E27 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 12PM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E28 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 3PM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E29 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 6PM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E30 of E33 Maximum UHS Temperature - 4 SX Pumps - 5 Days - 9PM Start 92 94 96 98 100 102 104 106 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Days Following Accident Plant Inlet Temp (°F)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E31 of E33 UHS Drawdown - 2 SX Pumps 588.0 588.2 588.4 588.6 588.8 589.0 589.2 589.4 589.6 589.8 590.0 590.2 0

5 10 15 20 25 30 Days Following Accident Elevation (ft)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E32 of E33 UHS Drawdown - 3 SX Pumps 588.0 588.2 588.4 588.6 588.8 589.0 589.2 589.4 589.6 589.8 590.0 590.2 0

5 10 15 20 25 30 Days Following Accident Elevation (ft)

Calculation No. ATD-0109, Rev. 4 Attachment E Page E33 of E33 UHS Drawdown - 4 SX Pumps 588.0 588.2 588.4 588.6 588.8 589.0 589.2 589.4 589.6 589.8 590.0 590.2 0

5 10 15 20 25 30 Days Following Accident Elevation (ft)

ATD-0109, Rev. 4 Page F1 of F3 Attachment F Electronic Files List (Additional electronic files are included with Attachments A and B) 2 SX Pump Cases

ATD-0109, Rev. 4 Page F2 of F3 3 SX Pump Cases

ATD-0109, Rev. 4 Page F3 of F3 4 SX Pump Cases Vendor Data Sheet for the Emergency Diesel Generator (EDG) Jacket Water Coolers

07/28198 10:58 FAX 1 412 458 3525 CB RECIPROCATING DBSIGN & PBRFOBMA.NCB DATA t* ONB UNlT llV.

NO.

lllUI 1Dtl PllNT!D IN U.J..A.

llVlllGN DAll CGOPEll*IE Calculation BRW-99-0306-M Revision 1 Attachment A Page A 1 of A 1 (FINAL)

Of -

1i10021003 Vendor Data Sheet for the Main Control Room Chiller Condenser

. -~ -*--**---

0 e

( )

UNIT DATA CONDENSER DATA Equipment No. OW001CA/CB WATER COOLED DATA SPECIFIED SUPPLIED Equlpmant Name Condenser pressure (pslg) 45.83 Control Room Refrigeration Unit Condenser lamp ("F}

116. g Condenser Manulacturer Entering l$rnp ("F}

(Max/Min) 100.0 MSD/Cc.rrier Model No.

19EA 7747DB Leaving temp ("f) 107.7 Refrigerant typa R-11 4 Pressure drop (pslg) 20 7.9 PHYSICAL DATA flow rate (gpm) 950 950 DATA SUPPLIED fletrlg. 1uctlon temp ("f) 38"F Type cl tubes SkiD Finnerl Capacity (BluH)

3. 687,000 No. cl tube passes 2

Fouling laclor 0.0015 0.0015 Total elf_ tube surlace (sq. It.)

3360 ft 2 Tube water veloclly (fpm) 6.4 ft /sec Tube material ASTM Alla~ 706 ASME SB 9

I fl REFERENCES Purchase specltlcatlon I L-2778 Vendor drawing A-12 Other S&I -Mfll fA-Ul 17"JO l';\\('iE l\\ /..o RELEASE RECORD CONDENSER DATA SHEET Rev Prepared Reviewed Approved Commo11wulth Edbon Company 0

CJ.

~

I* t., ~

/~~~**~)

t=.~VI~

~

~.

~-.&.,._ /t'J ~ J.tJ.. h Station Braidwood Unit H.2 1 r. P.nj Vf A, - \\.

I (l!Y-)h'.. £// 1.:i1J~)d1

(). y))

I 1...-LJ..i!.._.::;.,

f sARGENT a LUNDYI r

I

\\

~ ENOINEERS ~

Page 1 of 1

v t e Letter Sequence Request
CAC:MF4671, (Approved, Closed)
Initiation Request, Request Acceptance... Supplement Administration Meeting Questions 22 February 2016 Answers 30 April 2015 30 October 2015 9 November 2015 16 December 2015 29 April 2016 Results Approval Other:
MONTHYEAR2015-04-30 [Table View]

RS-14-193, Request for a License Amendment to Technical Specification 3.7.9, Ultimate Heat Sink

Text

Subject:

Reference:

Subject:

SUMMARY

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

SUMMARY

2.2 Background

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

4.3 CONCLUSION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

Title:

Subject:

Dear Mr. Panici,

5.0 REFERENCES

1.2 Background

5.0 REFERENCES

5.0 REFERENCES

SUMMARY

0.925 M Tw = transmission coefficient after absorption by water vapor

11.0 REFERENCES

Navigation menu

RS-14-193, Request for a License Amendment to Technical Specification 3.7.9, Ultimate Heat Sink

Text

Subject:

Reference:

Subject:

SUMMARY

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

SUMMARY

2.2 Background

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

4.3 CONCLUSION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

Title:

Subject:

Dear Mr. Panici,

5.0 REFERENCES

1.2 Background

5.0 REFERENCES

5.0 REFERENCES

SUMMARY

0.925 M Tw = transmission coefficient after absorption by water vapor

11.0 REFERENCES

Navigation menu

Search