ML21286A570
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BFN-28 Table 14.12-1 DBA Containment Response Key Analysis Input Values (Page 1 of 2)
Parameter Unit Value Reactor Initial Power Level (102% RTP) MWt 4,031 Normal Feedwater Temperature at 102% of 3952 MWt °F 394.5 Reduced Feedwater Temperature at 102% of 3952
°F 339.8 MWt RPV Dome Pressure psia 1,055 Decay Heat Model- Short Term DBA LOCA ANS 5 1971+20%
Decay Heat Model-Long Term 1979 ANS 5.1+2 RPV Free Volume ft3 20,682 RPV Liquid Volume - subcooled ft3 11,790 RPV Liquid Volume - saturated ft3 3,864 RPV Related Masses for Long Term Calculation Liquid mass in recirculation loops lbm 63,560 Liquid mass in the HPCI piping between the RPV lbm 8,621 nozzle and first normally closed valve Liquid mass in the RCIC piping between the RPV lbm 1,245 nozzle and first normally closed valve Liquid mass in the RHR piping between the RPV lbm 9,535 and the first normally closed valve Liquid mass in the core spray piping between the lbm 2,622 RPV nozzle and the first normal closed valve.
MSIV closure initiation second 0.5 MSIV full closure second 3.5 Drywell Vent System 159,000 to 171,000 Drywell free volume (including vent system) ft3 (Note 1)
Initial drywell pressure psia 15.1 to 17.0 Initial drywell Temperature 70 (D)
°F 130 (B)
(D=design, B=bounding, R=reference) 150 (R)
Initial drywell relative humidity (range) % 20 to 100 Downcomer submergence- Low water level ft 2.92
BFN-28 Table 14.12-1 DBA Containment Response Key Analysis Input Values (Page 2 of 2)
Parameter Unit Value Downcomer submergence- High water level ft 3.83 Loss coefficient for vent system including entrance and real 5.32 exit losses Downcomer internal diameter ft 1.958 Wetwell/Suppression Pool Initial Suppression pool volume including water in vents 3 ft 122,940
- low water level Initial Suppression pool volume including water in vents 3 ft 131,400
- high water level Initial pool temperature - maximum °F 95 Wetwell air volume excluding volume occupied by the ft3 135,000 (Note 2) vent system - Low water level Wetwell air volume excluding volume occupied by the ft3 119,400 vent system - High water level Initial wetwell/containment air space pressure (range) psia 14.4 to 15.9 Initial wetwell/containment airspace temperature
°F 95 (maximum)
Initial wetwell/containment air space relative humidity % 100 RHR K value (single HX) BTU/sec°F 265 RHR service water temperature °F 95 Drywell spray flow rate (2 RHR pumps) gpm 12,350 Wetwell spray flow rate (2 RHR pump) gpm 650 RHR flow rate in SPC mode (2 RHR pumps) gpm 13,000 Wetwell to Drywell Vacuum Breakers Pressure difference between wetwell and drywell for psid 0.5 (Note 3) vacuum breakers to be fully open Number of vacuum breaker assemblies 6 Flow area of each vacuum breaker assembly at which 1.41 loss coefficient is given below ft2 Loss coefficient or each vacuum breaker assembly Real 0.45 Notes:
(1) Vent thrust loads and LOCA analyses to minimize the containment pressure are calculated assuming a minimum DW volume of 159,000 ft3.
(2) This value is used for containment long-term analyses.
(3) For LOCA analyses that minimize the containment pressure response, the pressure difference between the wetwell and drywell for the vacuum breakers to be fully open of 0.05 psid is conservatively used.
BFN-28 Table 14.12-2 Non-Accident Unit Containment Response Key Analysis Input Values (Page 1 of 2)
Parameter Unit Value Reactor Initial power level 102% RTP MWt 4,031 Initial FW temperature at 102% RTP (102% of
°F 396.6 3,951MWt)
Initial vessel dome pressure at 102% RTP psia 1,055 Decay heat model N/A 1979 ANS 5.1 + 2 Vessel volumes Total vessel free volume ft3 20,682 Vessel liquid volume - subcooled ft3 7,926 Vessel liquid volume - saturated ft3 3,864 Vessel related masses Liquid mass in main steam lines to the inboard lbm 0 isolation valve Liquid mass in one recirculation loop lbm 31,780 Liquid mass in the HPCI piping between the RPV lbm 8,621 nozzle and first normally closed valve Liquid mass in RHR/LPCI shutdown piping between lbm 9,535 the RPV nozzle and first normally closed valve Liquid mass in the RCIC piping between the RPV lbm 1,245 nozzle and first normally closed valve Liquid mass in the CS piping between the RPV nozzle lbm 2,622 and the first normal closed valve MSIV Closure Time at which MSIVs start to close sec 0.5 Time at which MSIVs become fully closed sec 3.5 Drywell Total drywell airspace volume ft3 171,000 Initial drywell pressure psia 15.5 Initial drywell temperature °F 150 Initial drywell relative humidity % 20 Wetwell/Suppression Pool Initial suppression pool volume low water level (LWL) ft3 122,940 Initial suppression pool temperature °F 95 Initial wetwell airspace free volume - LWL in ft3 135,000 suppression pool Initial wetwell airspace pressure psia 14.4 Initial wetwell airspace temperature °F 95 Initial wetwell airspace relative humidity % 100
BFN-28 Table 14.12-2 Non-Accident Unit Containment Response Key Analysis Input Values (Page 2 of 2)
Parameter Unit Value RHR Heat exchanger K-value BTU/sec-°F 302 Service water temperature °F 95 RHR flow rate in suppression pool cooling mode gpm 9,700 RHR flow rate in SDC mode gpm 9,700 Number of RHR loops for cooling (one RHR loop is N/A 1 one RHR pump and one RHR heat exchanger)
RHR Service Water RHRSW flowrate through one RHR heat exchanger gpm 4,500 Condensate Storage Tank Condensate storage tank volume available for RPV gallon 135,000 inventory makeup Condensate storage tank temperature °F 130 Drywell Air Cooler Heat removal capability of each drywell air cooler BTU/hour 636,000
BFN-28 Table 14.12-3 Station Blackout Containment Response Key Analysis Input Values Parameter Value Initial Reactor Power 3,952 MWt Initial Reactor Pressure 1,055 psia Decay Heat ANS/ANSI 5.1 1979 standard consistent with recommendations of GEH SIL 636 Initial Suppression Pool 95°F Temperature Initial Suppression Pool 122,940 ft3 Volume (LWL)
Initial Wetwell Pressure 14.4 psia Initial Drywell Temperature 150°F Initial Drywell Pressure 15.5 psia Initial Drywell free airspace 171,000 ft3 volume Initial Wetwell free airspace 135,000 ft3 volume Initial WW airspace 95°F temperature CST Water Temperature 130°F CST Inventory 135,000 gallons available Initial Drywell Relative 20%
Humidity Initial Wetwell Relative 100%
Humidity RHR Heat exchanger K 265 BTU/Sec-°F factor (per heat exchanger)
RHR pump flow rate (per 6,500 gpm pump)
RHR service water flow 4,000 gpm rate to RHR heat exchangers RHR service water 95°F temperature Leakage rate from primary 2% of containment air mass per day containment Containment heat sinks Yes modeled
BFN-28 Table 14.12-4 Fire Event Containment Response Key Analysis Input Values Input Parameters Values Reactor Thermal Power 3,952 MWt RPV Dome Pressure 1,055 psia Decay Heat ANS 5.1-1979 without 2 uncertainty adder and with GEH SIL 636 recommendations Initial Suppression Pool Liquid Volume 122,940 ft3 (Note 1)
Initial Suppression Pool and Wetwell Airspace 92 °F (Note 2)
Temperature Initial Wetwell Pressure 14.4 psia Initial Drywell Pressure 15.5 psia Initial Drywell Temperature 150 °F Initial Wetwell Relative Humidity 100%
Initial Drywell Relative Humidity 20%
Drywell and Wetwell and Pool Heat Sinks Modeled Yes Drywell Heat Load Modeled Yes RHR Service Water Temperature 88 °F (Note 2)
RHR Heat Exchanger K Factor per Loop 290 Btu/sec-°F (Note 3)
Number of RHR Loops Available 1 Number of RHR Pump in one RHR Loop 1 ASDC RHR Flow Rate 7,500 gpm Condensate available for injection 90,000 gallons Notes (1) Suppression Pool Volume corresponding to Browns Ferry Technical Specification low suppression pool water level with differential pressure control in service.
(2) Nominal values based on Browns Ferry plant data over seven year period from January 2008 through December 2014. Data analysis for this parameter shows that Browns Ferry operates at least 95% of time below this value.
(3) RHR heat exchanger K factor based on RHR flow of 7,500 gpm, RHRSW flow of 4,500 gpm, RHRSW temperature of 88°F and conservative RHR heat exchanger fouling resistance.
BFN-28 Table 14.12-5 ATWS Event Containment Response Key Analysis Input Values (Page 1 of 2)
Input Variable Value Reactor power (MWt) 3,952 Analyzed Power (MWt) 3,952 Analyzed Core Flow (Mlbm/hr / % Rated) 101.475 / 99 Reactor dome pressure (psig) 1,035 MSIV Closure Time (seconds) 4.0 High pressure ATWS-RPT setpoint (psig) 1,177.0 MSL low pressure isolation setpoint (psig) 825 RCIC flow rate (gpm) 600 HPCI flow rate (gpm) 5,000 Number of MSRVs / MSRVs Out-of-service (OOS) 13 / 1 Number of MSRVs Out-of-service (OOS) 1 Each MSRV capacity at 1090 psig (Mlbm/hr) 0.87 MSRV Analytical Opening Setpoints (psig) 1,174 to 1,194 Note 1 SLCS Injection Location Lower Plenum SLCS Injection Rate (gpm) 50.0 Number of SLCS pumps credited for injection 1 Boron-10 Enrichment (Atom %) 94.0 Sodium Pentaborate Concentration (% by Weight) 8.7 SLCS Liquid Transport Time (seconds) 28.5 Initial Suppression Pool Liquid Volume (ft3) 122,940 Note 7 Initial Suppression Pool Temperature (°F) 95 RHR Heat Exchanger Effectiveness Per Loop 259 / 277 (BTU/sec-°F) Note 2 Number of RHR Suppression Pool Cooling Loops 4 (all events except Loss of Offsite Power Event)
Note 3 Number of RHR Suppression Pool Cooling Loops 2 During a Loss of Offsite Power Event Note 4
BFN-28 Table 14.12-5 ATWS Event Containment Response Key Analysis Input Values (Page 2 of 2)
Input Variable Value RHR startup delay (seconds after T = 0) 660 Note 5 RHR Service Water Temperature (°F) 95 Decay Heat Correlation May-Witt Note 6 Notes:
(1) In the ODYN analysis methodology, the MSRV setpoints for the ATWS analysis are statistically spread around the upper analytical limit.
(2) The heat exchanger effectiveness of 259 BTU/sec-°F assumes a RHR flow rate of 6500 gpm and RHR SW flow rate of 3800 gpm through each in-service RHR heat exchanger for events that assume operation of 4 RHR loops (see Note 3 below).
The EPU heat exchanger effectiveness of 277 BTU/sec-°F assumes a RHR flow rate of 6500 gpm and RHR SW flow rate of 4500 gpm through each in-service RHR heat exchanger for the event that assumes operation of 2 RHR loops (see Note 4 below).
(3) An RHR loop is defined as one RHR pump, one RHR heat exchanger and RHR SW flow of 3800 gpm through the RHR heat exchanger. For ATWS events other than LOOP, the plant operators would be directed by BFN Emergency Operating Instructions to maximize suppression pool cooling. Since there is no concurrent event on the non-ATWS unit, four RHR loops are assumed available for suppression pool cooling in the ATWS unit.
(4) An RHR loop is defined as one RHR pump, one RHR heat exchanger and RHR SW flow of 4500 gpm through the RHR heat exchanger. For the LOOP ATWS event, operators will be directed by BFN Emergency Operating Instructions to maximize suppression cooling. Since there is also a LOOP (without ATWS) on the remaining two Browns Ferry Units, only two RHR loops are assumed available for suppression pool cooling on the ATWS unit.
(5) The RHR startup delay time assumes no operator action for containment cooling for the first 10-minutes of the event with an additional 60 seconds for RHR to reach full effectiveness.
(6) The May-Witt decay heat correlation is used in the suppression pool temperature calculation following reactor shutdown. The May-Witt decay heat correlation yields a conservative pool heat-up compared to the 1979 ANS 5.1
+ 2 curve.
(7) The value of 122, 940 ft3 for the initial Suppression Pool Liquid Volume does not include the volumes of the ECCS ring header and the RHR piping for each running RHR pump. These two volumes were included in the assumptions for the ATWS containment analysis and result in a total suppression pool liquid volume of 127,000 ft3.
BFN-29 Table 14.12-6 Containment Response Results Parameter ST DBA LT LT Non- SBO (3) Fire ATWS (2)
LOCA DBA SSLB Accident Event LOCA Unit Peak Drywell 50.9 (D) 22.5 49.6 N/A 43.4 24.2 8.9 Pressure (psig) 49.1 (B) psia psia psia 48.5 (R)
Peak Drywell 297.5 (D) 287 336.9 N/A 275.2 276.3 N/A Airspace 295.8 (B)
Temperature (°F) 295.2 (R)
Peak Bulk 152.8(1) 179.0 182.7 185.1 203.7 207.7 174.5 Suppression Pool Temperature (°F)
Peak Torus N/A 30.2 48.0 N/A N/A 24.6 N/A (Wetwell) Pressure (psia)
Peak Torus (Wetwell) N/A 174 NA N/A N/A 209.0 N/A Air Temperature (°F)
N/A denotes a noncritical parameter for this analysis.
Notes:
(1) Peak Suppression Pool Temperature for RSLB DBA-LOCA at 10 minutes after LOCA initiation.
For the RDLB LOCA, the peak suppression pool temperature at 10 minutes after LOCA initiation is 152.0°F.
(2) Peak values from spectrum of SSLB analyses.
(3) Peak values from 0 gpm and 61 gpm reactor coolant system leakage cases