Safety-Related Air Conditioning, Heating, Cooling, and Ventilation Systems Calculations

Transcription

2 Revision History (Sheet 1 of 37) Revision 0 (Nov-2010) Page (Section) All 1 (Mar-2011) 7 Description Original issued Mitsubishi Heavy Industries, LTD. Table 3-1: - Cooling Coil Capacity in C, D-Class 1E Electrical Room Air Handling Unit is changed from 2,250,000 to 2,290,000. Section 5.1.1, Outdoor Air Intake: - Replaced Total required ventilation airflow is to be 1,637 cfm with Total required ventilation airflow is to be 1,635 cfm. Section , (3) Heat Gains: - Replaced Heat gains for CRE including 15% margin are 238,000 Btu/h with Heat gains for CRE including 15% margin are 242,000 Btu/h. - Replaced one AHU is to be 119,000 Btu/h per unit. with one AHU is to be 121,000 Btu/h per unit..

3 Revision History (Sheet 2 of 37) Revision 1 (Mar-2011) Page Description (Section) 23 Section , (5) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 13,000 Btu/h with Additional cooling load (additional margin) is 11,000 Btu/h Section , (4) Heat Gains: - Replaced...including 15% margin are 238,000 Btu/h... with...including 15% margin are 242,000 Btu/h... Section , (4) Heat Gains: - Replaced The cooling load per one AHU is to be 119,000 Btu/h. with The cooling load per one AHU is to be 121,000 Btu/h.. 25 Section , (6) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 24,000 Btu/h with Additional cooling load (additional margin) is 22,000 Btu/h Mitsubishi Heavy Industries, LTD.

4 Revision History (Sheet 3 of 37) Revision 1 (Mar-2011) Page (Section) 27 Description Section , (1) Outdoor Air: - Replaced...and 29.3 Btu/lb. with... and 29.5 Btu/lb.. - Replaced q = ( ) 1.15 = 188,370 Btu/h, USE 189,000 Btu/h with q = ( ) 1.15 = 185,679 Btu/h, USE 186,000 Btu/h. Section , (2.2) Return Air Fan Motor: - Editorial changed = 83,332 Btu/h, with = 83,323 Btu/h,. Section , (3) Heat Gains: 30 - Replaced...15% margin are 929,000 Btu/h with...15% margin are 966,000 Btu/h. 30 Section , (4) Additional Cooling Load (Additional margin): - Replaced...(additional margin) is 127,000 Btu/h with...(additional margin) is 93,000 Btu/h. 30 Mitsubishi Heavy Industries, LTD.

5 Revision History (Sheet 4 of 37) Revision 1 (Mar-2011) Page (Section) 31 Description Section , (1) Outdoor Air: - Replaced...and 30.1 Btu/lb. with...and 30.3 Btu/lb.. - Replaced q = ( ) 1.15 = 177,606 Btu/h, USE 180,000 Btu/h with q = ( ) 1.15 = 174,915 Btu/h, USE 175,000 Btu/h. Section , (3) Heat Gains: - Replaced Heat gains including 15% margin are 1,422,000 Btu/h (Train C: 939,000 Btu/h (Table ), Train D: 483,000 Btu/h (Table )) with Heat gains including 15% margin are 1,465,000 Btu/h (Train C: 973,000 Btu/h (Table ), Train D: 492,000 Btu/h (Table )). 33 Section , (4) Additional Cooling Load (Additional margin): - Replaced...(additional margin) is 119,000 Btu/h with...(additional margin) is 121,000 Btu/h. - Replaced...= 2,250,000 Btu/h with...= 2,290,000 Btu/h Mitsubishi Heavy Industries, LTD.

6 Revision History (Sheet 5 of 37) Revision 1 (Mar-2011) Page (Section) 34 Description Section , 44 Heat gains including 15% margin are changed from 23,000 to 21, Section , Additional cooling load is changed from 4,000 to 6, Mitsubishi Heavy Industries, LTD.

7 Revision History (Sheet 6 of 37) Revision 1 (Mar-2011) Page (Section) Description Section 5.6.1, Replaced The required airflow to establish a -1/4 inch w.g. pressure in the penetration areas and the safeguard component areas within 180 seconds with respect to adjacent areas is calculated by equation with The required airflow to establish a -0.4 inch w.g. pressure in the penetration areas and the safeguard component areas within 180 seconds with respect to adjacent areas is calculated by equation Section 5.6.1: - Remove the Volume decrease in the penetration areas (ΔV) is: ΔV = 3.14 x {( ) } x = , USE ft 3 CV expansion effect (ΔP) is: ΔP = 407 x {411,022 / (411, ) - 1 } = 0.67, USE 0.8 in. w.g.. 55 Section 6: - Replaced [2] ASHRAE Handbook Fundamentals-1981, ASHRAE with [2] ASHRAE Handbook Fundamentals-2005, ASHRAE Mitsubishi Heavy Industries, LTD.

8 Revision History (Sheet 7 of 37) Revision 1 (Mar-2011) Page (Section) 56 Description Mitsubishi Heavy Industries, LTD.

9 Revision History (Sheet 8 of 37) Revision 1 (Mar-2011) Page (Section) Description Mitsubishi Heavy Industries, LTD.

12 Revision History (Sheet 11 of 37) Revision 1 (Mar-2011) Page (Section) Description 58 Mitsubishi Heavy Industries, LTD.

18 Revision History (Sheet 17 of 37) Revision 1 Page (Section) Description (Mar-2011) Mitsubishi Heavy Industries, LTD.

19 Revision History (Sheet 18 of 37) Revision 1 (Mar-2011) Page (Section) 69 Description (Mar-2013) Abstract Add the new description at the last of paragraph. 1 Add the new description at the last of paragraph. 4 Table 2.2-1: - Add the Room of Class 1E MOV Inverter Room and Cable Tray Area Mitsubishi Heavy Industries, LTD.

20 Revision History (Sheet 19 of 37) Revision 2 (Mar-2013) Page (Section) 6 6 Description Mitsubishi Heavy Industries, LTD.

21 Revision History (Sheet 20 of 37) Revision 2 (Mar-2013) Page (Section) Description Table 3-1: - System Component Capacity (Sheet 1 of 3) in Unit Airflow Capacity of Class 1E Electrical Room Air Handling Unit (train A, B) is changed from 40,000 to 42, System Component Capacity (Sheet 1 of 3) in Unit Airflow Capacity of Class 1E Electrical Room Air Handling Unit (train C,D) is changed from 52,000 to 54,400. Table 3-1: - System Component Capacity (Sheet 1 of 3) in Cooling Coil Capacity of Class 1E Electrical Room Air Handling Unit (train A, B) is changed from 1,650,000 to 1,760, System Component Capacity (Sheet 1 of 3) in Cooling Coil Capacity of Class 1E Electrical Room Air Handling Unit (train C, D) is changed from 2,290,000 to 2,400,000. Table 3-1: - System Component Capacity (Sheet 1 of 3) in Fan Airflow Capacity of Class 1E Battery Room Exhaust Fan is changed from 2,600 to 3,200. Table 3-1: - System Component Capacity (Sheet 1 of 3) in Fan Airflow Capacity of Class 1E Electrical Room Return Air Fan (train A, B) is changed from 37,400 to 39, System Component Capacity (Sheet 1 of 3) in Fan Airflow Capacity of Class 1E Electrical Room Return Air Fan (train C, D) is changed from 49,400 to 51,200. Table 3-1: - System Component Capacity (Sheet 2 of 3) in Cooling Coil Capacity of EFW Pump (Motor-Driven) Area Air Handling Unit is changed from 110,000 to 115,000. Table 3-1: - System Component Capacity (Sheet 2 of 3) in Unit Airflow Capacity of EFW Pump (Turbine-Driven) Area Air Handling Unit is changed from 1,300 to 1,400. Table 3-1: - System Component Capacity (Sheet 2 of 3) in Cooling Coil Capacity of EFW Pump (Turbine-Driven) Area Air Handling Unit is changed from 62,000 to 65,000. Section , Outdoor Air Intake: - Added A conservative value of 1,800 cfm is used. Mitsubishi Heavy Industries, LTD.

22 Revision History (Sheet 21 of 37) Revision 2 (Mar-2013) Page (Section) Mitsubishi Heavy Industries, LTD. Description Section , (1) Outdoor Air: - Replaced Outdoor air intake is 1,800 cfm and enthalpy of outdoor air and return air are 43.3 Btu/lb and 30.0 Btu/lb. With The outdoor air intake is 1,800 cfm and the enthalpy of outdoor air and return air are 43.3 Btu/lb and 29.7 Btu/lb, respectively. - Replaced q = ( ) 1.15 = 123,890 Btu/h With q = ( ) 1.15 = 126,684 Btu/h. - Replaced During normal operation, two AHUs are in operation. Thus, the cooling load per one AHU is to be 61,945 Btu/h, USE 62,000 Btu/h per unit. with During normal operation, two AHUs are in operation. Thus, the cooling load per one AHU is to be 63,342 Btu/h. A conservative value of 64,000 Btu/h is used. Section , (3) Heat Gains: - Replaced Heat gains for CRE including 15% margin are 242,000 Btu/h obtained from Table During normal plant operation, two AHUs are in operation. Thus, The cooling load per one AHU is to be 121,000 Btu/h per unit. With Heat gains for the CRE including 15% margin are 228,000 Btu/h obtained from Table During normal plant operation, two AHUs are in operation. Thus, the cooling load per one AHU is to be 114,000 Btu/h per unit. Section , (4) Humidification: - Replaced When inside of Main Control Room is humidified from 51.9% RH as initial condition to 60% RH, Heat gain due to humidification is calculated by equation Airflow rate is 20,000 cfm and enthalpy before humidification and after humidification are 28.3 Btu/h and 30.0 Btu/h. With The Main Control Room heat gain due to humidification from an initial condition of 52.6% RH as initial condition to 60% RH, Heat gain due to humidification is calculated by equation Airflow rate is 20,000 cfm and enthalpy before humidification and after humidification are 28.2 Btu/h and 29.7 Btu/h, respectively. - Replaced q = ( ) 1.15 = 175,950 Btu/h with q = ( ) 1.15 = 155,250 Btu/h. Section , (4) Humidification: - Replaced Thus, the cooling load per one AHU is to be 88,000 Btu/h per unit. with Thus, the cooling load per one AHU is to be 78,000 Btu/h per unit.

23 Revision History (Sheet 22 of 37) Revision 2 (Mar-2013) Page (Section) 22 Description Section , (5) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 11,000 Btu/h with Additional cooling load (additional margin) is 26,000 Btu/h Mitsubishi Heavy Industries, LTD.

24 Revision History (Sheet 23 of 37) Revision 2 (Mar-2013) Page (Section) Description Section , (1) Outdoor Air: - Replaced Outdoor air intake is 1,200 cfm, enthalpy of outdoor air and return air are 43.3 Btu/lb and 28.2 Btu/lb with Outdoor air intake is 1,200 cfm, while the enthalpy of outdoor air and return air are 43.3 Btu/lb and 28.1 Btu/lb. - Replaced q = ( ) 1.15 = 93,771 Btu/h with q = ( ) 1.15 = 94,392 Btu/h. - Replaced Thus, the cooling load per one AHU is to be 46,886 Btu/h, USE 47,000 Btu/h per unit with Thus, the cooling load per one AHU is to be 47,196 Btu/h. A conservative value of 48,000 Btu/h is used. Section , (4) Heat Gains: - Replaced Heat gains for CRE including 15% margin are 242,000 Btu/h obtained from Table with Heat gains for CRE including 15% margin are 228,000 Btu/h obtained from Table Replaced During emergency pressurization mode operation, two AHUs are in operation. Thus, The cooling load per one AHU is to be 121,000 Btu/h. with During emergency pressurization mode operation, two AHUs are in operation. Thus, the cooling load per one AHU is to be 114,000 Btu/h. Section , (6) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 22,000 Btu/h with Additional cooling load (additional margin) is 28,000 Btu/h. Mitsubishi Heavy Industries, LTD.

25 Revision History (Sheet 24 of 37) Revision Page (Section) Description 2 (Mar-2013) Mitsubishi Heavy Industries, LTD.

26 Revision History (Sheet 25 of 37) Revision 2 (Mar-2013) Page (Section) Description Section 5.2.1, Outdoor Air Intake Requirement: - Replaced Outdoor air intake requirement is to be approximately 2,600 cfm obtained from CERVS calculation sheet. Therefore, the Class 1E battery room exhaust fan capacity is to be determined as 2,600 cfm with Outdoor air intake requirement is to be approximately 3,200 cfm obtained from the CERVS calculation sheet. Therefore, the Class 1E battery room exhaust fan capacity is to be determined as 3,200 cfm. Section 5.2.1, Class 1E Electrical Room AHU Airflow Requirements: - Replaced Therefore, airflow capacity for train A&B AHUs is 40,000 cfm, and for train C&D AHUs is 52,000 cfm with Therefore, airflow capacity for train A&B AHUs is 42,300 cfm, and for train C&D AHUs is 54,400 cfm. Section 5.2.1, Class 1E Electrical Room Return Air Fan Capacity: - Replaced Therefore, A,B-Class 1E Electrical Room return air fan capacity is to be 37,400 cfm, and C,D-Class 1E Electrical Room return air fan capacity is to be 49,400 cfm with Therefore, A,B-Class 1E Electrical Room return air fan capacity is to be 39,100 cfm, and C,D-Class 1E Electrical Room return air fan capacity is to be 51,200 cfm. Mitsubishi Heavy Industries, LTD.

27 Revision History (Sheet 26 of 37) Revision 2 (Mar-2013) Page (Section) Description Section (1) Outdoor Air: - Replaced Outdoor air intake is 2,600 cfm and enthalpy of outdoor air and return air are 43.3 Btu/lb and 29.5 Btu/lb with Outdoor air intake is 3,200 cfm and enthalpy of outdoor air and return air are 43.3 Btu/lb and 29.3 Btu/lb, respectively. - Replaced q = ( ) 1.15 = 185,679 Btu/h, USE 186,000 Btu/h with q = ,200 ( ) 1.15 = 231,840 Btu/h. A conservative value of 232,000 Btu/h is used. Section (2.1) AHU Fan Motor: - Replaced Airflow rate requirement is 40,000 cfm with Airflow rate requirement is 42,300 cfm. - Replaced q = / ( ) 1.15 = 320,920 Btu/h, USE 321,000 Btu/h with q = ,300 / ( ) 1.15 = 339,373 Btu/h. A conservative value of 340,000 Btu/h is used. Section (2.2) Return Air Fan Motor: - Replaced Airflow rate requirement is 37,400 cfm with Airflow rate requirement is 39,100 cfm. - Replaced q = / ( ) 1.15 = 83,323 Btu/h, USE 84,000 Btu/h with q = ,100 / ( ) 1.15 = 87,110 Btu/h. A conservative value of 88,000 Btu/h is used. - Replaced Therefore, total cooling load of fan motors is 405,000 Btu/h with Therefore, total cooling load of fan motors is 428,000 Btu/h. Section (3) Heat Gains: - Replaced Heat gains including 15% margin are 966,000 Btu/h obtained from Table with Heat gains including 15% margin are 992,000 Btu/h obtained from Table Section (4) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 93,000 Btu/h with Additional cooling load (additional margin) is 108,000 Btu/h. - Replaced Total cooling load = (1)+(2)+(3)+(4) = 1,650,000 Btu/h with Total cooling load = (1)+(2)+(3)+(4)= 1,760,000 Btu/h. 29 Mitsubishi Heavy Industries, LTD.

28 Revision History (Sheet 27 of 37) Revision 2 (Mar-2013) Page (Section) 30 Description Section (1) Outdoor Air: - Replaced Outdoor air intake is 2,600 cfm. Enthalpy of outdoor air and return air are 43.3 Btu/lb and 30.3 Btu/lb with Outdoor air intake is 3,200 cfm. Enthalpy of outdoor air and return air are 43.3 Btu/lb and 30.1 Btu/lb, respectively. - Replaced q = ( ) 1.15 = 174,915 Btu/h, USE 175,000 Btu/h with q = ,200 ( ) 1.15 = 218,592 Btu/h. A conservative value of 219,000 Btu/h is used. Mitsubishi Heavy Industries, LTD.

29 Revision History (Sheet 28 of 37) Revision 2 (Mar-2013) Page (Section) Description Section (2.1) AHU Fan Motor: - Replaced Airflow rate requirement is 52,000 cfm with Airflow rate requirement is 54,400 cfm. - Replaced q = / ( ) 1.15 = 417,197 Btu/h, USE 418,000 Btu/h with q = ,400 / ( ) 1.15 = 436,452 Btu/h. A conservative value of 437,000 Btu/h is used. Section (2.2) Return Air Fan: - Replaced Airflow rate requirement is 49,400 cfm with Airflow rate requirement is 51,200 cfm. - Replaced q = / ( ) 1.15 =110,057 Btu/h, USE 111,000 BTU/h with q = ,200 / ( ) 1.15 =114,067 Btu/h. A conservative value of 115,000 Btu/h is used. - Replaced Therefore, total cooling load of fan motors is 529,000 Btu/h with Therefore, total cooling load of fan motors is 552,000 Btu/h. Section (3) Heat Gains: - Replaced Heat gains including 15% margin are 1,465,000 Btu/h with Heat gains including 15% margin are 1,492,000 Btu/h. - Replaced (Train C: 973,000 Btu/h (Table ), Train D: 492,000 Btu/h (Table )) with (Train C: 465,000 Btu/h (Table ), Train D: 1,027,000 Btu/h (Table )). Section (3) Heat Gains: - Replaced Additional cooling load (additional margin) is 121,000 Btu/h with Additional cooling load (additional margin) is 137,000 Btu/h. - Replaced Total cooling load = (1)+(2)+(3)+(4) = 2,290,000 Btu/h with Total cooling load = (1)+(2)+(3)+(4)= 2,400,000 Btu/h Mitsubishi Heavy Industries, LTD.

30 Revision History (Sheet 29 of 37) Revision 2 (Mar-2013) Page (Section) Description Section (1) Fan Motors: - Replaced q = / ( ) 1.15 = 18,234 Btu/h, USE 19,000 Btu/h with q = / ( ) 1.15 = 18,234 Btu/h. A conservative value of 19,000 Btu/h is used. Section (2) Internal Heat Gain (Except for Fan Motors): - Replaced Heat gain from equipment, piping, lighting, and structure is 109,498 Btu/h obtained from Table USE 126,000 Btu/h added the 15% margin (16,502 Btu/h) with Heat gain from equipment, piping, lighting, and structure is 109,322 Btu/h obtained from Table A conservative value of 126,000 Btu/h including the 15% margin (16,678 Btu/h). Mitsubishi Heavy Industries, LTD.

31 Revision History (Sheet 30 of 37) Revision 2 (Mar-2013) Page (Section) Description Section 5.4 Emergency Feedwater Pump Area HVAC System (EFWPAVS): - Replaced Table with Table Section Outdoor Air Intake: - Replaced Total required ventilation airflow is to be 85 cfm per EFW pump (turbine-driven) area Table with Total required ventilation airflow is to be 87 cfm per EFW pump (turbine-driven) area Table Section Cooling Airflow Requirements: - Replaced Table with Table Section AHU Airflow Requirements: - Replaced Total cooling airflow for motor-driven and turbine-driven area is 2,100 cfm and 1,300 cfm (See Table 5.4-1) with Total cooling airflow for motor-driven and turbine-driven area is 2,100 cfm and 1,400 cfm (See Table ). Section (2) Internal Heat Gains: - Replaced Heat gain from pumps, piping and supports, lighting and concrete walls, including 15% margin, is 105,000 Btu/h obtained from Table with Heat gain from pumps, piping and supports, lighting and concrete walls, including 15% margin, is 109,000 Btu/h obtained from Table Section (3) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 1,900 Btu/h with Additional cooling load (additional margin) is 2,900 Btu/h. - Replaced Total cooling load = (1)+(2)+(3) = 110,000 Btu/h with Total cooling load = (1)+(2)+(3) = 115,000 Btu/h Mitsubishi Heavy Industries, LTD.

32 Revision History (Sheet 31 of 37) Revision 2 (Mar-2013) Page (Section) Description Section (1) Outdoor Air: - Replaced Heat gain from outdoor is calculated by equation Outdoor air intake is 100 cfm, enthalpy of outdoor air and return air are 43.3 Btu/lb and 35.6 Btu/lb with Heat gain from outdoor air is calculated by equation Outdoor air intake is 100 cfm, enthalpy of outdoor air and return air are 43.3 Btu/lb and 35.3 Btu/lb. - Replaced q = ( ) 1.15 = 3,985 Btu/h with q = ( ) 1.15 = 4,140 Btu/h. - Replaced Thus, the cooling load per one AHU is to be 4,000 Btu/h. with Thus, the cooling load per one AHU is to be 5,000 Btu/h. Section (2) Fan Motors: - Replaced Airflow rate requirement is 1,300 cfm with Airflow rate requirement is 1,400 cfm. - Replaced q = / ( ) 1.15 = 1,896 Btu/h with q = / ( ) 1.15 = 2,042 Btu/h. - Replaced Thus, cooling load of fan motor is 2,000 Btu/h with Thus, cooling load of the fan motor is 3,000 Btu/h. Section (3) Internal Heat Gains: - Replaced Heat gain from pumps, piping and supports, lighting and concrete walls, including 15% margin, is 54,000 Btu/h obtained from Table with Heat gain from pumps, piping and supports, lighting and concrete walls, including 15% margin, is 57,000 Btu/h obtained from Table Mitsubishi Heavy Industries, LTD.

33 Revision History (Sheet 32 of 37) Revision 2 (Mar-2013) Page (Section) Description Section (4) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 2,000 Btu/h with Additional cooling load (additional margin) is 0 Btu/h. - Replaced Total cooling load = (1)+(2)+(3)+(4) = 62,000 Btu/h with Total cooling load = (1)+(2)+(3)+(4) = 65,000 Btu/h Section 5.5 Safety Related Component Area HVAC System (SRCAVS): - Replaced Table with Table Mitsubishi Heavy Industries, LTD.

34 Revision History (Sheet 33 of 37) Revision 2 (Mar-2013) Page (Section) Description Section Cooling Airflow Requirements: - Replaced Table with Table Section AHU Airflow Requirements: - Replaced Table with Table Section (2) Heat Gains: - Replaced Table with Table Section (2) Heat Gains: - Replaced Heat gains including 15% margin are 21,000 Btu/h obtained from Table with Heat gains including 15% margin are 23,000 Btu/h obtained from Table Section (2) Heat Gains: - Replaced Heat gains including 15% margin are 285,000 Btu/h obtained from Table with Heat gains including 15% margin are 281,000 Btu/h obtained from Table Mitsubishi Heavy Industries, LTD.

35 Revision History (Sheet 34 of 37) Revision 2 (Mar-2013) Page (Section) 47 New paragraph is added in Description Section (4) Additional Cooling Load (Additional margin): - Replaced Additional cooling load (additional margin) is 26,000 BTU/h with Additional cooling load (additional margin) is 18,000 BTU/h. - Replaced Total cooling load = (1)+(2)+(3) = 330,000 Btu/h with Total cooling load = (1)+(2)+(3)+(4) = 330,000 Btu/h Mitsubishi Heavy Industries, LTD.

36 Revision History (Sheet 35 of 37) Revision 2 (Mar-2013) Page (Section) Description Section (2) Heat Gains: - Replaced Table with Table Section (2) Heat Gains: - Replaced Table with Table Section 5.6.1: - Replaced V: Volume in the penetration area 411,022 ft 3 with V: Volume in the penetration area 409,249 ft 3. - Replaced ΔP = 407 x {411,022 / (411, ) - 1 } = 0.67, USE 0.8 in. w.g with ΔP = 407 x {409,249 / (409, ) - 1 } = A conservative value of 0.8 in. w.g. is used. - Added A conservative value of ft 3 is used. after V = =3.14 x {( ) } x = Added A conservative value of ft is used. after R = 68 x / (4,769 x 10 3 x 4.33) x (1 0.17/2) = Replaced 60 ( ) 411,022 Q = + 1,500 = ( ) with 60 ( ) 409,249 Q = + 1,500 = ( ) - Replaced V: Volume of safeguard component areas, 312,426 ft 3 with V: Volume of safeguard component areas, 311,819 ft 3. - Replaced 60 ( ) 312,426 Q = + 1,500 = ( ) with 60 ( ) 311,819 Q = + 1,500 = ( ) Mitsubishi Heavy Industries, LTD.

38 Revision History (Sheet 37 of 37) Revision 2 (Mar-2013) Page (Section) Description All pages The descriptions in this technical report are revised to provide readability without technical changes. Mitsubishi Heavy Industries, LTD.

39 C 2013 MITSUBISHI HEAVY INDUSTRIES, LTD. All Rights Reserved This document has been prepared by Mitsubishi Heavy Industries, Ltd. ( MHI ) in connection with the U.S. Nuclear Regulatory Commission s ( NRC ) licensing review of MHI s US-APWR nuclear power plant design. No right to disclose, use or copy any of the information in this document, other that by the NRC and its contractors in support of the licensing review of the US-APWR, is authorized without the express written permission of MHI. This document contains technology information and intellectual property relating to the US-APWR and it is delivered to the NRC on the express condition that it not be disclosed, copied or reproduced in whole or in part, or used for the benefit of anyone other than MHI without the express written permission of MHI, except as set forth in the previous paragraph. This document is protected by the laws of Japan, U.S. copyright law, international treaties and conventions, and the applicable laws of any country where it is being used. Mitsubishi Heavy Industries, Ltd. 16-5, Konan 2-chome, Minato-ku Tokyo Japan Mitsubishi Heavy Industries, LTD.

40 Abstract The purpose of this technical report is to present calculations on the heating, cooling and airflow requirements of the safety-related air conditioning, heating, cooling, and ventilation systems of US-APWR. The safety-related air conditioning, heating, cooling, and ventilation systems of US-APWR include the Main Control Room Heating, Ventilation and Air Conditioning (HVAC) System (MCRVS), the Class 1E Electrical Room HVAC System (CERVS), the Safeguard Component Area HVAC System (SCAVS), the Emergency Feedwater Pump Area HVAC System (EFWPAVS), the Safety Related Component Area HVAC System (SRCAVS) and the Annulus Emergency Exhaust System (AEES). This report provides the calculations of the cooling and airflow requirements for the operating mode of each of these air conditioning, heating, cooling, and ventilation system. Some design information such as heat gain from equipment and components will be updated as the design progresses and includes design enhancements outside the scope of standard US-APWR design. This technical report will also be updated when the HVAC system specifications are revised due to heat gain changes identified during the design progression. Mitsubishi Heavy Industries, LTD.

41 Table of Contents List of Tables... iii List of Figures... iv List of Acronyms... v 1. INTRODUCTION DESIGN CONDITION Outdoor Air Condition Room Air Condition Ventilation Requirement Internal Heat Gains Electrical Boards Lighting People Components Piping and Supports Surface Temperature of Exterior Roofs and Walls Heat Gain or Loss through Roofs, Walls and Floors Supply Air Temperature Fan Total Pressure Other Design Consideration Safeguard Component Area HVAC System Annulus Emergency Exhaust System SUMMARY OF COMPONENT CAPACITY EQUATION Airflow Rate Requirements Cooling Airflow Requirements Ventilation Requirements for Removal of Hydrogen Airflow Requirements for AEES Heat Gains Outdoor Air or Infiltration Air Fan in case of Motor in Airstream Humidification Air Temperature Rise across Fans and Electrical Heaters Cooling Capacity CALCULATIONS Main Control Room HVAC System (MCRVS) Airflow Requirement Cooling Coil Requirement Normal Operation Mode Emergency Pressurization Mode Class 1E Electrical Room HVAC System (CERVS) Airflow Requirement Cooling Coil Requirement A,B-Class 1E Electrical Room Air Handling Unit C,D-Class 1E Electrical Room Air Handling Unit Safeguard Component Area HVAC System (SCAVS) Airflow Requirement Mitsubishi Heavy Industries, LTD. i

42 5.3.2 Cooling Coil Requirement Emergency Feedwater Pump Area HVAC System (EFWPAVS) Airflow Requirement Cooling Coil Requirement Motor-Driven Pump Area Air Handling Unit Turbine-Driven Pump Area Air Handling Unit Safety Related Component Area HVAC System (SRCAVS) Airflow Requirement Cooling Coil Requirement Essential Chiller Unit Area AHU Cooling Coil CCW Pump Area AHU Cooling Coil Charging Pump Area AHU Cooling Coil Penetration Area AHU Cooling Coil Annulus Emergency Exhaust Filtration Unit Area AHU Cooling Coil Spent Pump Pit Area AHU Cooling Coil Annulus Emergency Filtration System (AEES) Airflow Requirement for Penetration Areas Airflow Requirement for Safeguard Component Areas Annulus Emergency Exhaust Fan EFU Airflow Requirements REFERENCE Mitsubishi Heavy Industries, LTD. ii

43 List of Tables Table Conditioned Air Design Values 4 Table Ventilation Requirements 5 Table Heat Gain from Electrical Boards 6 Table Heat Gain from Lighting 7 Table Heat Gain from Components 8 Table Heat Gain from Piping and Supports 9 Table Surface Temperature of Exterior Roofs and Walls 9 Table Thermal Insulation Properties 10 Table Supply Air Temperature 10 Table Fan Total Pressure 11 Table Specific Design Conditions of SCAVS 11 Table Specific Design Conditions of AEES 12 Table 3-1 System Component Capacity 13 Table MCRVS Calculation Sheet 56 Table MCRVS Return Air Temperature Condition (Normal Operation 57 Mode) Table MCRVS Return Air Temperature Condition (Emergency 57 Pressurization Mode) Table CERVS Calculation Sheet 58 Table Cooling and Heating Loads in Non-Safety Related Portion of 59 CERVS Train-D following Accident Condition Table CERVS Return Air Temperature 60 Table SCAVS Cooling and Heating Loads 61 Table SCAVS Calculation Sheet (During Normal Operation Severed by 62 AUXVS) Table SCAVS Calculation Sheet (During Abnormal Plant Operation) 63 Table SCAVS Airflow Ratio of Normal to Abnormal Operation 64 Table SCAVS Return Air Temperature Condition 65 Table EFWPAVS Calculation Sheet 66 Table EFWPAVS Return Air Temperature Condition 67 Table SRCAVS (Essential Chiller Unit Area) Calculation Sheet 68 Table SRCAVS (CCW Pump Area) Calculation Sheet 68 Table SRCAVS (Charging Pump Area) Calculation Sheet 69 Table SRCAVS (Annulus Area) Calculation Sheet 70 Table SRCAVS (Annulus Emergency Exhaust Filtration Unit Area) 71 Calculation Sheet Table SRCAVS (Spent Fuel Pit Pump Area) Calculation Sheet 71 Table SRCAVS Return Air Temperature Condition 72 Mitsubishi Heavy Industries, LTD. iii

44 List of Figures Figure MCRVS Psychometric Chart (Normal Operation Mode) 73 Figure MCRVS Psychometric Chart (Emergency Pressurization Mode) 74 Figure MCRVS Airflow Distribution Sketch (Emergency Pressurization 75 Mode) Figure CERVS Train A&B Psychometric Chart 76 Figure CERVS Train C&D Psychometric Chart 77 Figure SCAVS Psychometric Chart 78 Figure EFWPAVS (Motor-Driven Pump Area) Psychometric Chart 79 Figure EFWPAVS (Turbine-Driven Pump Area) Psychometric Chart 80 Figure SRCAVS (Essential Chiller Unit Area) Psychometric Chart 81 Figure SRCAVS (CCW Pump Area) Psychometric Chart 82 Figure SRCAVS (Charging Pump Area) Psychometric Chart 83 Figure SRCAVS (Penetration Area) Psychometric Chart 84 Figure SRCAVS (Annulus Emergency Exhaust Filtration Unit Area) 85 Psychometric Chart Figure SRCAVS (Spent Fuel Pit Pump Area) Psychometric Chart 86 Mitsubishi Heavy Industries, LTD. iv

45 List of Acronyms The following list defines the acronyms used in this document. AAC ACH AEES AHU ASHARE AUXVS CCW CERVS CLTD CRDM CRE CS DB EFU EFW EFWPAVS ESF FU HVAC I&C LOCA LOOP LRT MCR MCRVS M-G R/B RH RHR RSC SCAVS SFP SI SRCAVS UPS WB WG Alternate AC Air Change per Hour Annulus Emergency Exhaust System Air Handling Unit American Society of Heating, Refrigerating and Air-Conditioning Engineers Auxiliary Building HVAC System Component Cooling Water Class 1E Electrical Room HVAC System Cooling Load Temperature Differential Control Rod Drive Mechanism Control Room Envelope Containment Spray Dry Bulb Emergency Filtration Unit Emergency Feedwater Emergency Feedwater Pump Area HVAC System Engineered Safety Features Filtration Unit Heating, Ventilation and Air Conditioning System Instrumentation and Control Loss of Coolant Accident Loss of Offsite Power Leakage Rate Testing Main Control Room Main Control Room HVAC System Motor-Generator Reactor Building Relative Humidity Residual Heat Removal Remote Shutdown Console Safeguard Component Area HVAC System Spent Fuel Pit Safety Injection Safety Related Component Area HVAC System Uninterruptible Power Supply Wet Bulb Water Gauge Mitsubishi Heavy Industries, LTD. v

46 1. INTRODUCTION This document contains calculations on the cooling and airflow requirement of the safety-related HVAC systems. The safety-related HVAC systems are as follows: Main Control Room HVAC System (MCRVS) Class 1E Electrical Room HVAC System (CERVS) Safeguard Component Area HVAC System (SCAVS) Emergency Feedwater Pump Area HVAC System (EFWPAVS) Safety Related Component Area HVAC System (SRCAVS) Annulus Emergency Exhaust System (AEES) The information presented in this technical report will be updated in the future as the design progresses; including design enhancements outside the scope of standard US-APWR design. This technical report will also be updated when the HVAC system specifications are changed due to heat gain changes identified during the design progression. Mitsubishi Heavy Industries, LTD. 1

47 2. DESIGN CONDITION This chapter summarizes the design conditions for calculating the cooling and airflow requirements of the safety-related HVAC systems. 2.1 Outdoor Air Condition The safety-related HVAC systems are designed with zero (0) percent exceedance values to accommodate all environmental conditions. The 0% exceedance temperatures are used in the following calculation. 0% exceedance maximum : 115 o F (DB) / 80 o F (WB) 2.2 Room Air Condition The conditioned air design values for rooms served by the safety-related HVAC systems are specified in Table Ventilation Requirement The air ventilation requirements for rooms served by the safety-related HVAC systems are specified in Table The class 1E battery room exhaust system is designed to maintain the hydrogen concentration below 1% by volume in accordance with Regulatory Guide (Reference 1). 2.4 Internal Heat Gains The internal heat gains from electrical boards, lights, people, and components that can contribute the majority of the cooling load in the building are shown in following sections Electrical Boards The heat gain from the electrical boards in each room is specified in Table Lighting The heat gain from lighting for each room is specified in Table People The heat gain from people in the control room envelope (CRE) is specified as 350 Btu/h per person Components The heat gain from the components in each room (e.g., thermal heat exchangers and pumps etc.) is shown in Table Piping and Supports The heat gain from the piping and its supports in each room is specified in Table Surface Temperature of Exterior Roofs and Walls Mitsubishi Heavy Industries, LTD. 2

48 The values used for determining the conductive heat gain through exterior walls and roofs are specified in Table The values are based on the Cooling Load Temperature Differential (CLTD) method in the ASHRAE Fundamentals Handbook-1981 (Reference 2), Chapter Heat Gain or Loss through Roofs, Walls and Floors Roofs and walls exposed to outside air are provided with thermal insulation to minimize heat loss from air-conditioned areas. The thermal insulation properties are specified in Table The effect of the thermal insulation is ignored when the heat gains through roofs and walls are calculated. 2.7 Supply Air Temperature The supply air temperature provided to each area served by the HVAC systems are specified in Table Fan Total Pressure The total design pressure of each air handling unit supply fan is specified in Table This value is used to estimate the air temperature rise across the fan. 2.9 Other Design Consideration The SCAVS and the AEES are designed to account for these specific design considerations: The SCAVS connects to the Auxiliary Building HVAC system (AUXVS) supply and exhaust ducts. During normal operation, the AUXVS serves the safeguard component areas via the SCAVS distribution ductwork. During a design basis accident or Loss of Offsite Power (LOOP), the safeguard component areas are cooled by individual safeguard component area air handling units. The AEES is designed to establish a - 1/4 inch water gauge (WG) pressure in the penetration areas and the safeguard component areas within 240 seconds to mitigate potential leakage to the environment of fission products from the containment following a Loss of Coolant Accident (LOCA) Safeguard Component Area HVAC System The following specific design considerations are applied to SCAVS calculations and the specific design values associated with these considerations are summarized in Table Water leakage from Engineered Safety Features (ESF) components during accident condition Infiltration from surrounding areas during accident condition Use of common distribution ductwork Annulus Emergency Exhaust System Specific design conditions applied to the AEES are summarized in Table Mitsubishi Heavy Industries, LTD. 3

49 Table Conditioned Air Design Values HVAC System Rooms Air Condition MCRVS CERVS SCAVS Main Control Room (Including sub-room) Class 1E I&C Room Remote Shutdown Console Room Class 1E Battery Room MCR/Class 1E Electrical HVAC Equipment Room MCR Emergency Supply Filtration Unit & Fan Room Class 1E Electrical Room Class 1E Battery Charger Room Class 1E UPS Room AAC Selector Circuit Panel Room Reactor Trip Breaker Room M-G Set Room M-G Set Control Panel Room CRDM Cabinet Room LRT Room Class 1E MOV Inverter Room Cable Tray Area SI Pump Room CS/RHR Pump Room CS/RHR Heat Exchanger Room Safeguard Component Area AHU Room R/B Sump Tank Room o F 25-60% RH o F o F o F o F o F o F ( o F) (Note) EFWPAVS EFW Pump Area o F SRCAVS CCW Pump Area Charging Pump Room Penetration Area Annulus Emergency Exhaust Filtration Unit Area Spent Fuel Pit Pump Area Essential Chiller Unit Area o F o F Note : During normal plant operation, the safeguards component areas are maintained within this temperature range by the AUXVS through the distribution ductwork of the SCAVS. Mitsubishi Heavy Industries, LTD. 4

50 Table Ventilation Requirements Mitsubishi Heavy Industries, LTD. 5

51 Table Heat Gain from Electrical Boards Mitsubishi Heavy Industries, LTD. 6

52 Table Heat Gain from Lighting Mitsubishi Heavy Industries, LTD. 7

53 Table Heat Gain from Components Mitsubishi Heavy Industries, LTD. 8

54 Table Heat Gain from Piping and Supports Table Surface Temperature of Exterior Roofs and Walls Mitsubishi Heavy Industries, LTD. 9

55 Table Thermal Insulation Properties Table Supply Air Temperature Mitsubishi Heavy Industries, LTD. 10

56 Table Fan Total Pressure Table Specific Design Conditions of SCAVS Mitsubishi Heavy Industries, LTD. 11

57 Table Specific Design Conditions of AEES Mitsubishi Heavy Industries, LTD. 12

58 3. SUMMARY OF COMPONENT CAPACITY The safety-related HVAC system component capacity is summarized in Table 3-1. Table 3-1 System Component Capacity (Sheet 1 of 3) Main Control Room Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 10,000 per unit 341,000 per unit Main Control Room Toilet/Kitchen Exhaust Fan Fan Airflow Capacity, cfm 1,800 per unit Main Control Room Smoke Purge Fan Fan Airflow Capacity, cfm 20,000 per unit Class 1E Electrical Room Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 42,300 per unit - train A, B 54,400 per unit - train C, D 1,760,000 per unit - train A, B 2,400,000 per unit - train C, D Class 1E Battery Room Exhaust Fan Fan Airflow Capacity, cfm 3,200 per unit Class 1E Electrical Room Return Air Fan Fan Airflow Capacity, cfm 39,100 per unit - train A, B 51,200 per unit - train C, D Safeguard Component Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 5,000 per unit 180,000 per unit Mitsubishi Heavy Industries, LTD. 13

59 Table 3-1 System Component Capacity (Sheet 2 of 3) EFW Pump (Motor-Driven) Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 2,100 per unit 115,000 per unit EFW Pump (Turbine-Driven) Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 1,400 per unit 65,000 per unit Essential Chiller Unit Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 1,000 per unit 30,000 per unit CCW Pump Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 1,000 per unit 30,000 per unit Charging Pump Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 1,000 per unit 10,000 per unit Penetration Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 5,000 per unit 330,000 per unit Annulus Emergency Exhaust Filtration Unit Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 1,000 per unit 10,000 per unit Mitsubishi Heavy Industries, LTD. 14

60 Table 3-1 System Component Capacity (Sheet 3 of 3) Spent Fuel Pit Pump Area Air Handling Unit Unit Airflow Capacity, cfm Cooling Coil Capacity, Btu/h 1,500 per unit 100,000 per unit Annulus Emergency Exhaust Filtration Unit & Fan Design flow rate, cfm 5,600 per unit Mitsubishi Heavy Industries, LTD. 15

61 4. EQUATION The equations applied to calculate the following requirements are as follows. 4.1 Airflow Rate Requirements Cooling Airflow Requirements Cooling airflow requirements are calculated by following equations. These equations are generally used to estimate the airflow rate for cooling. Q = q / (60 ρ C p (t i - t o )) α : equation where, Q : Airflow rate requirements, cfm q : Heat Loads, Btu/h C p : Specific heat, 0.24 Btu/lb- o F ρ : Density, lb/ft 3 t i : Design room temperature, o F t o : Supply air temperature, o F α : Margin, Ventilation Requirements for Removal of Hydrogen Adequate Class 1E battery room ventilation is required to prevent the accumulation of hydrogen. The required airflow through the battery room is in accordance with BS EN (Reference 3). The required ventilation airflow rate is calculated by the following equation: Q = v g s n I gas Cn 10-3 : equation where, Q : Airflow rate requirements, cfm v : Necessary dilution of hydrogen g : Hydrogen gas evolution rate, cfm/cell-a s : General safety factor n : Number of cells I gas : Current producing gas in ma per Ah, Amp/Ah ( = I boost f g f s ) I boost : Typical boost charge current, Amp/Ah f g : Gas emission factor f s : Gas emission safety factor Cn : Capacity for lead acid cells, Ah Airflow Requirements for AEES The AEES exhaust airflow rate to establish required negative pressure in the penetration areas and the safeguard component areas within the required drawn-down time with respect to adjacent areas is calculated by the following equation. Mitsubishi Heavy Industries, LTD. 16

62 ( P + ΔP) V Qin ( T T ) 60 Q = + P 0 f : equation where, Q : Required airflow, cfm P : Establishing negative pressure, in. w.g. P 0 : Surrounding area ambient pressure (Standard air), in. w.g. P : CV expansion effect, in. w.g. V : Free volume of penetration and safeguard component areas, ft 3 T : Time of establishing the design negative pressure, sec. T f : Time of reaching fan design airflow rate, sec. Q in : Infiltration to the penetration area and safeguard component area, cfm CV expansion effect ( P) is calculated by the following equation. P=P x {V / (V - V) - 1} : equation where, P : Effect of the expansion of CV, in. w.g. P : Initial pressure, in. w.g. V : Volume in the penetration area, ft 3 V : Volume decrease in the penetration area, ft 3 Volume decrease (DV) in the penetration areas is calculated by the following equation. V=3.14 x {(R cvo + DR) 2 R cvo 2 } x h : equation where, V : Volume decrease in the penetration area, ft 3 R cvo : Outside radius of CV, ft R : Radial expansion of CV, ft h : Height of the penetration area, ft Radial expansion of CV (DR) is calculated by the following equation. R = P x R 2 / (E x t) (1 - ν/2) : equation where, R : Radial expansion of CV, ft P : Internal pressure of CV, psig R : Average radius of CV, ft t : Thickness of CV, ft E : Modulus of elasticity for concrete, ksi ν : Poisson s ratio 4.2 Heat Gains This section calculates the heat load from the outdoor intake, infiltration air, fan operation, and humidification. Mitsubishi Heavy Industries, LTD. 17

63 4.2.1 Outdoor Air or Infiltration Air Heat gain from outdoor air and infiltration is calculated by the following equation. q = 60 ρ Q (h i -h o ) α : equation where, q : Heat gain from outdoor, Btu/h ρ : Density, lb/ft 3 Q : Outdoor air intake or infiltration air, cfm h i : Enthalpy of outdoor air or infiltration air, Btu/lb h o : Enthalpy of return air or room air, Btu/lb α : Margin, Fan in case of Motor in Airstream Heat gain from the fan motor and drive inside the airstream is calculated by the following equation. q = H Q / (h f η m ) α : equation where, q : Fan motor load, Btu/h H : Fan total pressure, in. w.g. Q : Airflow rate requirement, cfm h f : Fan efficiency (Note1) h m : Motor efficiency (Note2) α : Margin, 1.15 Note: 1. Typical centrifugal fan and axial fan efficiency use 0.7 and A typical motor efficiency use Humidification Heat gain due to humidification is calculated by the following equation. q = 60 ρ Q (h o - h i ) α : equation where, q : Cooling load, Btu/h ρ : Density, lb/ft 3 Q : Airflow rate, cfm h i : Enthalpy before humidification, Btu/h h o : Enthalpy after humidification, Btu/h α : Margin, Air Temperature Rise across Fans and Electrical Heaters Mitsubishi Heavy Industries, LTD. 18

64 The outlet air temperature from fan associated with electrical heaters increases when the entering air passes through the electrical heaters. The equations to determine the temperature rise of the entering air temperature is discussed in the following sections. (a) Temperature Rise across fan The air temperature rise across fan is calculated by the following equation. t = H / (1.08 x η f η m ) : equation where, t : Temperature rise across fan, o F H : Fan total pressure, in. w.g. η f : Fan efficiency (Note1) η m : Motor efficiency (Note2) Note: 1. Values for typical centrifugal fan and axial fan efficiency of 0.7 and 0.55 are used respectively. 2. A typical value for motor efficiency of 0.9 is used. (b) Temperature Rise across electrical heaters The air temperature rise across the electric heater is calculated by the following equation. t o = q / (60 x Q ρ C p ) + t i : equation where, t o : Exiting air temperature, o F q : Heat gain from electric heating coil, Btu/h Q : Airflow rate, cfm C p : Specific heat, 0.24 Btu/lb- o F ρ : Density, lb/ft 3 t i : Inlet air temperature, o F 4.4 Cooling Capacity The cooling capacity is calculated by the following equation. q = 60 ρ Q (h i - h o ) α : equation where, q : Cooling requirement, Btu/h ρ : Density, lb/ft 3 Q : AHU airflow, cfm h i : Enthalpy of cooling coil inlet, Btu/lb h o : Enthalpy of cooling coil outlet, Btu/lb α : Margin, 1.15 Mitsubishi Heavy Industries, LTD. 19

65 5. CALCULATIONS This chapter contains the calculations for each safety-related HVAC System including the AEES. 5.1 Main Control Room HVAC System (MCRVS) Table summarizes the MCRVS airflow requirements based on cooling requirements Airflow Requirement Outdoor Air Intake Outdoor air intake flow is determined in accordance with the requirements shown in Table Total required ventilation airflow is to be 1,635 cfm shown in Table A conservative value of 1,800 cfm is used. Exhaust Fan Flow The toilet/kitchen exhaust fans discharge air from the CRE through the toilet/kitchen area. The exhaust fan is designed to be capable of extracting fresh air equivalent to makeup airflow requirements from the outdoor environment. Therefore, the capacity of the exhaust fan is 1,800 cfm. Cooling Airflow Requirements Cooling airflow requirements are calculated by equation Required cooling airflow for each area is shown in Table AHU Airflow Requirements According to the MCRVS calculation sheet (Table ), total cooling airflow is approximately 20,000 cfm. The MCR supply system consists of 4 units (50% x 4 ). Thus, one AHU airflow capacity is to be 10,000 cfm. Smoke Purge Fan Airflow Requirement The MCR HVAC system is designed so that the outside air quantity will be increased to 100 percent of system supply air flow rate during smoke purge operation in accordance with URD (Reference 5). Thus the smoke purge fan is designed to be capable of exhausting a maximum 20,000 cfm purging air from the MCR. The capacity of the main control room smoke purge fan is to be 20,000 cfm Cooling Coil Requirement The conditioned air requirement of the cooling coils is determined for both normal operation mode and the emergency pressurization mode. During emergency pressurization mode operation, the emergency filtration unit electrical heating coils are energized to reduce relative humidity below 70% RH to ensure charcoal adsorber efficiency. Psychrometric charts containing air properties during normal operation and emergency operation are shown in Mitsubishi Heavy Industries, LTD. 20