ABS Consulting Fukushima Daiichi Correlating Fukushima Doses ABS

  • Slides: 46
Download presentation
ABS Consulting Fukushima Dai-ichi Correlating Fukushima Doses

ABS Consulting Fukushima Dai-ichi Correlating Fukushima Doses

ABS Consulting Fukushima Area

ABS Consulting Fukushima Area

ABS Consulting Plant Description and Initial Status n n 6 Units — Unit 1

ABS Consulting Plant Description and Initial Status n n 6 Units — Unit 1 is a BWR 3 rated at 460 MWe — Units 2 -5 are BWR 4’s rated at 784 Mwe — Unit 6 is a BWR 5 rated at 1100 Mwe Status at time of earthquake and tsunami — Units 1 -3 were operating — Units 4 -6 were shut down

ABS Consulting Chronology: Initiating Event n At 14: 46 JST on 11 March 2011

ABS Consulting Chronology: Initiating Event n At 14: 46 JST on 11 March 2011 a 9. 0 magnitude occurred off the East coast of Japan about 130 km East of Sendai — Resulted in loss of offsite power — Units 1, 2 and 3 shut down — Diesel generators started

ABS Consulting Chronology: Tsunami n At 15: 41 JST, a tsunami generated by the

ABS Consulting Chronology: Tsunami n At 15: 41 JST, a tsunami generated by the earthquake energy hit the coast of Japan at Fukushima Dai-ichi — Heights up to 38. 9 m — Height at the site of the Fukushima Dai-ichi plant was probably about 14. 5 m based on examination of the plant after the event — Flooded emergency diesel generators resulting in complete loss of alternating current for Units 1, 2, and 3 at 15: 42 JST. — First Level Emergency declared

ABS Consulting Tsunami Heights In Japan Credit: Wikipedia

ABS Consulting Tsunami Heights In Japan Credit: Wikipedia

ABS Consulting Tsunami Height at Fukushima Dai-ichi

ABS Consulting Tsunami Height at Fukushima Dai-ichi

ABS Consulting Chronology: Site-wide Actions After Station Blackout (SBO) n Evacuation ordered by government

ABS Consulting Chronology: Site-wide Actions After Station Blackout (SBO) n Evacuation ordered by government — To 3 km on 12 March at 03: 00 — To 10 km on 12 March at 07: 00 — To 20 km on 12 March at 19: 11 n On 12 March at 15: 29 radiation at the site boundary exceeded the limiting value n On 12 March at 15: 36 a large aftershock occurs

ABS Consulting Chronology: Unit 1 After SBO n Reactor steam initially cooled by the

ABS Consulting Chronology: Unit 1 After SBO n Reactor steam initially cooled by the isolation condenser. n At 16: 36, status of reactor coolant water injection could not be confirmed. n At 3: 48 on 12 March, water injection by Makeup Water Condensate system began. n At 5: 22, temperature in suppression chamber exceeded 100 C, which caused it to lose the suppression function.

ABS Consulting Chronology: Unit 1 After SBO, cont. n At 15: 36 on 12

ABS Consulting Chronology: Unit 1 After SBO, cont. n At 15: 36 on 12 March immediately after the large aftershock, a large explosion accompanied by smoke damages the upper floor of the reactor. n At 20: 20 started injection of seawater with boric acid into the reactor core.

ABS Consulting Chronology: Unit 2 After SBO n Reactor steam initially cooled by the

ABS Consulting Chronology: Unit 2 After SBO n Reactor steam initially cooled by the isolation condenser, but status unclear. Reactor coolant level stable. n At 16: 36, status of reactor coolant water injection could not be confirmed. n On 14 March at 13: 25, water injection with the RCIC was lost. n At 17: 17, water reached top of fuel rods and water injection was restarted.

ABS Consulting Chronology: Unit 2 After SBO, cont. n On 15 March at 06:

ABS Consulting Chronology: Unit 2 After SBO, cont. n On 15 March at 06: 14, an “extraordinary sound” was reported near the suppression chamber and the chamber pressure then decreased. This is now believed to have been a hydrogen explosion inside the secondary containment.

ABS Consulting Chronology: Unit 3 After SBO n Reactor shutdown and cooled by Reactor

ABS Consulting Chronology: Unit 3 After SBO n Reactor shutdown and cooled by Reactor Core Isolation Cooling System. n By 13 March at 05: 10, the HPCI had stopped and attempts to restart the RCIC had failed n Vent valve opened to relieve containment pressure at 08: 41 n Injection of seawater and boric acid initiated at 09: 25 using a fire pump

ABS Consulting Chronology: Unit 3 After SBO, cont. n On 14 March at 11:

ABS Consulting Chronology: Unit 3 After SBO, cont. n On 14 March at 11: 01, there was an explosive sound followed by white smoke, believed to have been a hydrogen explosion. The damages the upper floor of the reactor building.

ABS Consulting Chronology: Unit 4 after SBO n Unit 4 was shut down at

ABS Consulting Chronology: Unit 4 after SBO n Unit 4 was shut down at the time of the accident, but lost spent fuel pool cooling on 11 March at the time of SBO. n On 15 March at 06: 00, a loud explosion was heard from the reactor building and the rooftop sustained extensive damage. n On 16 March at 05: 45, an employee discovers a fire at the northwest corner of the reactor building. Fire was out by 06: 15

ABS Consulting Plant Schematic Credit: NEI

ABS Consulting Plant Schematic Credit: NEI

ABS Consulting The Decay Heat Removal Problem

ABS Consulting The Decay Heat Removal Problem

ABS Consulting Decay Heat Removal Systems n n Reactor Core Isolation Cooling System (RCIC)

ABS Consulting Decay Heat Removal Systems n n Reactor Core Isolation Cooling System (RCIC) — Steam-driven pump — Can draw from condensate storage tank or suppression pool High Pressure Coolant Injection System (HPCI) — Turbine and turbine-driven pumps — Can draw from condensate storage tank or suppression pool

ABS Consulting Decay Heat Removal Systems, cont. n Both RCIC and HPCI rely on

ABS Consulting Decay Heat Removal Systems, cont. n Both RCIC and HPCI rely on battery power to activate valves and run instrumentation. When the batteries die, the systems are of limited utility. n Both systems also rely on having an “ultimate heat sink” outside containment to cool the water in the system.

ABS Consulting Decay Heat Removal Systems, cont. n When the ultimate heat sink is

ABS Consulting Decay Heat Removal Systems, cont. n When the ultimate heat sink is lost, the temperature and pressure in the reactor builds up. — If the pressure is not relieved, the reactor cooling system piping can rupture. — If the pressure is relieved, the water will evaporate and eventually uncover the fuel. The zirconium cladding will then oxidize in steam and produce hydrogen.

ABS Consulting Decay Heat Removal Systems, cont. n When the hydrogen is released and

ABS Consulting Decay Heat Removal Systems, cont. n When the hydrogen is released and the valves are open, it can build in a confined space, leading to a hydrogen explosion. n A similar scenario can happen with spent fuel, but because the fuel has had longer to decay, it boils the spent fuel pool water off more slowly. However, it can become uncovered and generate hydrogen like the reactor core.

ABS Consulting Before Accident 4 3 2 1 6 5 Credit: Google Earth

ABS Consulting Before Accident 4 3 2 1 6 5 Credit: Google Earth

ABS Consulting After Accident 4 3 2 1 6 5 Credit: Google Earth

ABS Consulting After Accident 4 3 2 1 6 5 Credit: Google Earth

ABS Consulting Meteorological Data During Period of Important Release (15 March 2011)

ABS Consulting Meteorological Data During Period of Important Release (15 March 2011)

ABS Consulting Meteorological Data During Period of Important Release (16 March 2011)

ABS Consulting Meteorological Data During Period of Important Release (16 March 2011)

ABS Consulting SENDAI WIND ROSES

ABS Consulting SENDAI WIND ROSES

ABS Consulting SENDAI WIND ROSE MARCH 15 -18

ABS Consulting SENDAI WIND ROSE MARCH 15 -18

ABS Consulting FUKUSHIMA WIND ROSES

ABS Consulting FUKUSHIMA WIND ROSES

ABS Consulting FUKUSHIMA WIND ROSE MARCH 15 -18

ABS Consulting FUKUSHIMA WIND ROSE MARCH 15 -18

ABS Consulting FUKUSHIMA 5 -YR WIND ROSE ANNUAL AND SPRING SEASON

ABS Consulting FUKUSHIMA 5 -YR WIND ROSE ANNUAL AND SPRING SEASON

ABS Consulting Estimated Source Term n The source term was estimated by examining the

ABS Consulting Estimated Source Term n The source term was estimated by examining the ground dose as measured by NNSA helicopter overflights — It was assumed that all activity was deposited on the ground — I 131 was separated from Cs 137 and Cs 134 by comparing the mid-March to end of March data. — Cs 134 and Cs 137 were assumed equal based on isotopic essays of ground samples.

ABS Consulting Estimated Source Term, cont. n Release multiplied by 3 to estimate effects

ABS Consulting Estimated Source Term, cont. n Release multiplied by 3 to estimate effects of peak/contour edge ratio n Final source term estimate was: — I 131: 1. 8 E 6 Ci — Cs 134: 2. 4 E 5 Ci — Cs 137: 2. 4 E 5 Ci

ABS Consulting Estimated Source Term, cont. n n No noble gases in release —

ABS Consulting Estimated Source Term, cont. n n No noble gases in release — They could not be estimated from available data — Could change results considerably Release duration of two hours starting on 15 March 2011 at 09: 00 JST based on events and monitoring data

ABS Consulting MIDAS Results, 24 Hour TEDE Dose

ABS Consulting MIDAS Results, 24 Hour TEDE Dose

ABS Consulting MIDAS Results, 24 Hour Thyroid Dose

ABS Consulting MIDAS Results, 24 Hour Thyroid Dose

ABS Consulting MIDAS Results, EDE Dose Rate at 24 Hours

ABS Consulting MIDAS Results, EDE Dose Rate at 24 Hours

ABS Consulting MIDAS Results, TEDE Dose Rate at 24 Hours

ABS Consulting MIDAS Results, TEDE Dose Rate at 24 Hours

ABS Consulting MIDAS Results, Thyroid Dose Rate at 6 Hours

ABS Consulting MIDAS Results, Thyroid Dose Rate at 6 Hours

ABS Consulting MIDAS Results, 1 Year Committed Ground Shine

ABS Consulting MIDAS Results, 1 Year Committed Ground Shine

Results of NNSA Monitoring Flights ABS Consulting Taken from USDOE Presentation of 22 March

Results of NNSA Monitoring Flights ABS Consulting Taken from USDOE Presentation of 22 March 2011

Results of NNSA Monitoring Flights ABS Consulting Taken from USDOE Presentation of 7 April

Results of NNSA Monitoring Flights ABS Consulting Taken from USDOE Presentation of 7 April 2011

ABS Consulting Current Plant Status Unit 1 n Core Damage Level — Drywell damage

ABS Consulting Current Plant Status Unit 1 n Core Damage Level — Drywell damage ~45% — Wetwell damage ~10% — Total ~55% n Reactor cooling restored n Fuel pool cooling restored n Extensive damage to top level of containment

ABS Consulting Current Plant Status Unit 2 n Core Damage Level — Drywell damage

ABS Consulting Current Plant Status Unit 2 n Core Damage Level — Drywell damage ~30% — Wetwell damage <5% — Total ~35% n Reactor cooling restored n Fuel pool cooling restored n No visible damage to containment

ABS Consulting Current Plant Status Unit 3 n Core Damage Level — Drywell damage

ABS Consulting Current Plant Status Unit 3 n Core Damage Level — Drywell damage ~25% — Wetwell damage <5% — Total ~30% n Reactor cooling restored n Fuel pool cooling restored n Extensive damage to top level of containment

ABS Consulting Current Plant Status Unit 4 n No Core Damage (Reactor was undergoing

ABS Consulting Current Plant Status Unit 4 n No Core Damage (Reactor was undergoing routine maintenance) n Fuel pool cooling restored, some damage to one wall of pool n Extensive damage to top level of containment

ABS Consulting Current Plant Status Units 5 and 6 n No Core Damage (Reactors

ABS Consulting Current Plant Status Units 5 and 6 n No Core Damage (Reactors were undergoing routine maintenance) n Fuel pool cooling restored early, no damage to fuel n No damage to containment