CNSC Staff Briefing CMD 11-M15 March 30, 2011

Transcription

1 CNSC Staff Briefing CMD 11-M15 March 30, 2011

2 CNSC Response CNSC took action immediately to: Activate Emergency Operations Centre on 3 rd floor Slater (11-March) Staff Nuclear Emergency Organization in accordance with CNSC Emergency Response Plan adapted to foreign emergency Create a Japan Executive Team (senior CNSC executives) 24-7 operation w Technical, External Liaison, Communications and Logistics teams Active participation from across CNSC CNSC Staff Briefing CMD 11-M15-2

3 Nuclear Emergency Organization CNSC Staff Briefing CMD 11-M15-3

4 CNSC Role CNSC Role: Evaluate situation and possible outcomes, Provide credible information and advice, Continue to regulate Focus Areas: Impact on Embassy Staff (through DFAIT) Impact on Canadians in Japan (through DFAIT) Impact on Canada (through Public Safety Canada) Impact on Canadian NPPs CNSC Staff Briefing CMD 11-M15-4

5 Federal Government DFAIT Lead for actions in Japan CNSC attend daily meetings/teleconferences CNSC support to Ambassador Public Safety Canada Government Operations Centre (GOC) Lead for Canadian domestic response CNSC Liaison Officer stationed at GOC CNSC provide daily situation reports to GOC Close links between CNSC, Health Canada and Environment Canada Minimum daily meeting or teleconference From staff level to DM level Regular ADM EMC teleconferences CBSA, CFIA, PHAC Support to Provincial Emergency and Health authorities Federal Nuclear Emergency Plan (FNEP) not activated: Coordination by HC CNSC Staff Briefing CMD 11-M15-5

6 International CNSC established links with USA, UK, FRA regulators Daily teleconferences Information exchange and validation IAEA CNSC access to IAEA secure emergency info web site Limited information coming from Japan Canadian mission at IAEA in Vienna (VPERM) Two Canadian experts to Vienna to support IAEA CNSC AECL CNSC Staff Briefing CMD 11-M15-6

7 Overview of Japan Event Reactor Design and Features Chronology of Events Station Photos of Damage Radiation Protection Considerations Updates Arial View of Japan s Dai-ichi NPP March 2011 CNSC Actio ns and Follow-up CNSC Staff Briefing CMD 11-M15-7

8 Reactor Design GE MARK I BWR CNSC Staff Briefing CMD 11-M15-8

9 Canadian Nuclear Safety Commission Commission canadienne de sûreté nucléaire Reactor Building Elevation View and Under Construction nuclearsafety.gc.ca Canada CNSC Staff Briefing CMD 11-M15-9

10 Canadian Nuclear Commission canadienne Reactor Safety and Commission Control de sûreté nucléaire Rod Design nuclearsafety.gc.ca Canada CNSC Staff Briefing CMD 11-M15-10

11 GE MARK I BWR Plant System Schematic CNSC Staff Briefing CMD 11-M15-11

12 GE MARK I BWR Fuel Pool CNSC Staff Briefing CMD 11-M15-12

13 Initiating Event The Fukushima nuclear facilities experienced a magnitude 9 earthquake on March 11th centered offshore of the Sendai region, which contains the capital Tokyo Plant designed for magnitude 8.2 earthquake A 9 magnitude quake is 8 times stronger in energy Followed by a significant tsunami of 14m high - more than double station design Over 750 aftershocks since including some as large as magnitude 6.5 CNSC Staff Briefing CMD 11-M15-13

14 Event Chronology Initial Station Response Note: Our understanding of this event will change. It is based on information received to date. The description is general and is not intended as an accurate chronology of events as they occurred. Nuclear reactors were shutdown automatically. Within seconds the control rods were inserted into core and nuclear chain reaction stopped Cooling systems were placed in operation to remove the residual heat. The residual heat load is about 3% of the heat load under normal operating conditions Earthquake resulted in the loss of offsite power (normal supply to plant) Emergency Diesel Generators started and powered station emergency cooling systems CNSC Staff Briefing CMD 11-M15-14

15 Event Chronology Initial Station Response One hour later, the station was struck by the tsunami. The tsunami was larger than what the plant was designed for. The tsunami took out all multiple sets of the backup Emergency Diesel generators Reactor operators were able to utilize emergency battery power to provide power for cooling the core for 8 hours Operators followed abnormal operating procedures and emergency operating procedures CNSC Staff Briefing CMD 11-M15-15

16 Event Chronology Offsite power could not be restored and delays occurred obtaining, connecting portable generators After the batteries ran out, residual heat could not be carried away Reactor temperatures increased and water levels in the reactor decreased, eventually uncovering and overheating the core Hydrogen was produced from metal-water reactions in the reactor (Oxidation of zirconium) Operators vented the reactor to relieve steam pressure - energy (and hydrogen) was releaseded into the primary containment (drywell) causing increased primary containment temperatures and pressures CNSC Staff Briefing CMD 11-M15-16

17 Event Chronology Operators took actions to vent the primary containment to control containment pressure and hydrogen levels. Required to protect the primary containment from failure Primary Containment Venting is through a filtered path that travels through duct work in the secondary containment to an elevated release point on the refuel floor (on top of the reactor building) A hydrogen detonation subsequently occurred while venting the secondary containment. Occurred shortly after and aftershock at the station CNSC Staff Briefing CMD 11-M15-17

18 Event Chronology Hydrogen Explosions CNSC Staff Briefing CMD 11-M15-18

19 Event Chronology As a result of the explosions in units 1 and 3 reactor buildings collapse around the containment At this time the primary containments and reactor pressure vessels are intact After the initial few hours and through the event, severe accident management procedures were initiated Seawater injected into the primary loop Off-site electrical power sources brought on-site Fire hoses used for dousing As pressure builds in the primary containments, operators vent to relieve the pressure and release hydrogen On-site and off-site radiological releases Explosion occurs in unit 2 damage to primary containment is suspected CNSC Staff Briefing CMD 11-M15-19

20 Event Chronology At various times off-site emergency response is taken to evacuate people from the vicinity initially 3 km, subsequently increased to 20 km Authorities recommend sheltering between 20 km and 30 km. Eventually recommend evacuation Fires occurred at various location both in the units and in the spent fuel storage pools Spent fuel storage pools lose cooling Radiation hazard impedes recovery efforts CNSC Staff Briefing CMD 11-M15-20

21 Station Photos of Damage CNSC Staff Briefing CMD 11-M15-21

22 Station Photos of Damage CNSC Staff Briefing CMD 11-M15-22

23 Station Photos of Damage CNSC Staff Briefing CMD 11-M15-23

24 Station Photos of Damage CNSC Staff Briefing CMD 11-M15-24

25 Event Chronology TEPCO continues to try to restore power and reliable cooling Radioactive water increasing in turbine building Environmental radiation levels fluctuating and food controls being implemented Today the situation is. CNSC Staff Briefing CMD 11-M15-25

26 Unit Power (MINeAh) Type of Reaclor BW R-3 BWR4 BWR4 BWR4 Status at time of EQ Core and fuel RPV 8, RCS integrity Containment integrity AC Power Building Water level of R PI! In service - auto shutdown I n service - auto shutdown Damage suspected In service - auto shutdown Outage Pressure of RPV CV Pressure Drywall Water injection to RPV Water injection to CV Spent Fuel Pool Status No information No information

27 Canadian Nuclear Safety Commission Commission canadienne de sûreté nucléaire nuclearsafety.gc.ca Canada CNSC Staff Briefing CMD 11-M15-27

28 Initial Lessons Learnt from the Fukushima Event We must not underestimate the importance of Capability of the plant to mitigate natural events such as earthquake, flood, tsunami, tornado, fire events Capability of the plant to mitigate combined natural events such as flooding resulting from an earthquake Capability of the plant for station blackout Capability of the plant to mitigate severe accidents including loss of major safety systems (for example, robust power supply for a long term) Effective Severe Accident Management Program Effective emergency planning CNSC Staff Briefing CMD 11-M15-28

29 CNSC Actions Based on Events in Japan We responded to initial lessons learnt: General Nuclear Safety and Control Regulations 12(2) CNSC site staff actions We will verify the effectiveness of defence-in-depth strategy and measures CNSC Staff Briefing CMD 11-M15-29

30 General Nuclear Safety and Control Regulations 12(2) All CANDU licensees requested to reexamine safety cases for: external hazards such as seismic, flooding, fire and extreme weather events measures for prevention and mitigation of severe accidents emergency preparedness Report on implementation plans for shortand long-term measures to address any identified gaps CNSC Staff Briefing CMD 11-M15-30

31 CNSC Site Staff Actions Inspections of Power Reactors: Seismic Readiness of Secondary Control Room/seismic route Availability of manuals and procedures Fire Confirmation of minimum shift complement monitoring Arrangements for off-site support Backup power availability and condition Hydrogen Igniters Routine testing to confirm availability CNSC Staff Briefing CMD 11-M15-31

32 CNSC Site Staff Actions (2) Inspections of (irradiated) Spent Fuel Bays: Readiness of components and equipment Provision/availability of makeup water and heat sinks Verification of alarms on flow, temperature, and stack release CNSC Staff Briefing CMD 11-M15-32

33 Defence-in-Depth Strategy and Measures In addition to steps already taken, we will verify the effectiveness of defence-in depth strategy and measures implemented to assure: Prevention of abnormal operation and failures Control of abnormal operation and detection of failures Control of accidents within the design basis Control of severe plant conditions - prevention of accident progression and mitigation of consequences of severe accidents Mitigation of radiological consequences of significant releases of radioactive materials CNSC Staff Briefing CMD 11-M15-33

34 Conclusion The scale of earthquake and resulting tsunami of Fukushima is not credible for Canadian site CNSC requires that reactor designs consider all natural events (such as earthquake, tsunami, flooding, tornado) as design basis events appropriate to the site Designs are required to consider combined events (for example, flooding resulting from an earthquake) as design basis events CNSC Staff Briefing CMD 11-M15-34

35 Conclusion (2) Station blackout, one of the worst consequences of these common-cause events must be considered by Licensees CNSC requires that severe accident management guidelines be in place and that licensee s review their emergency preparedness Detailed lessons learnt from the Fukushima event will be considered for the design and operation of all Canadian nuclear power plants Implementing these lessons must be undertaken and a Leadership Team has been established co-chaired by the DG- DPRR and DG-DAA CNSC Staff Briefing CMD 11-M15-35

36 CNSC Staff Briefing CMD 11-M15-36