#1NRA, Japan Nuclear Regulation Authority Keynote Presentation Summary on Fukushima Related Activities in Japan Masashi HIRANO Director-General for Regulatory Standard and Research Nuclear Regulation Authority (NRA) International Conference on Challenges Faced by TSOs in Enhancing Nuclear Safety and Security: Strengthening Cooperation and Improving Capabilities, 27-31 October 2014, Beijing, China#2NRA, Japan Nuclear Regulation Authority Contents ■ Overview ■ Current Status of Safety Regulation ■ Creation of NRA ■ Technical Independence Merger of JNES with NRA New Regulatory Requirements. Safety Research Current Status of Fukushima Daiichi Fuel Removal from Spent Fuel Pools ■ Contaminated Water Issues ■ Summary and Challenges as a TSO 1#3NRA, Japan Nuclear Regulation Authority Current Status of Safety Regulation ■ NRA was established in Sep. 2012 and developed the new regulatory requirements for NPPs which came into force in July 2013. ■ All the 48 units have been shut down since Sep. 2013. So far, a total of 20 units, 12 PWRs and 8 BWRs, have applied for conformance review for restart. ■ In Sep. 2014, NRA first approved the applications from Sendai Units 1 and 2. ■ The new requirements for fuel cycle facilities and research reactors came into force in Dec. 2013. ■ The former JNES was merged with NRA on Mar. 1, 2014. 2 As of Oct. 1, 2014 Tomari-1-3 Higashidori Kashiwazaki- Kariwa-6-7 Shika-2 Ohi-3~4 Rokkasyo Fuel Reprocéssing Facility Onagawa-2 NRA invited the IAEA IRRS mission to be taken place in late 2015. Takahama-3~4 Shimane -2 Genkai-3~4 Tokai Daini Hamaoka-4 : PWR Ikata-3 Sendai-1~2 : BWR#4NRA, Japan Nuclear Regulation Authority Some Lessons Learned Identified in Diet's Report (Reported to Diet in July 2012) Message from Chairman NAIIC: The National Diet's Fukushima Nuclear Accident Independent Investigation Commission ■ ... this was a disaster "Made in Japan." Its fundamental causes are to be found in the ... Japanese culture: our reflexive obedience; our reluctance to question authority; ... and our insularity. Organizational issues ... actual relationship lacked independence and transparency, In fact, it was a typical example of "regulatory capture," . Lack of expertise the two incorporated technical agencies advising NISA, namely, JNES and JAEA, have been too rigidly tied to NISA .... Conclusions The lack of expertise resulted in "regulatory capture,"... They avoided their direct responsibilities by letting operators apply regulations on a voluntary basis. 3#5NRA, Japan Nuclear Regulation Authority NRA: Nuclear Regulation Authority Established in Sept. 2012 ■ Independence Nuclear regulation and nuclear promotion were clearly separated, and the NRA was established as an independent commission body defined by law* affiliated with MOE (Minister of Environment). * a council-system organization based on Article 3 of the National Government Organization Act, ensuring its independence without any control or supervision by other organizations. Integrated and Independent ■ Integrated Nuclear regulation functions regarding safety, security, safeguards, radiation monitoring and radioisotopes were integrated into the NRA. NRA MOE MOE AEC METI MEXT AEC NRA METI Security NISA NSC Commercial facilities RR, RI, Safeguards, Monitoring Safety, 2nd Check Security, Safeguards, etc. MEXT • T. Fuketa, NRA, presented at U.S.NRC RIC2013, March 13, 2013. •http://www.nsr.go.jp/english/e_nra/leaflet/data/nsr_leaflet_English .pdf 4 AEC Atomic Energy Commission METI Ministry of Economy, Trade and Industry MEXT: Ministry of Education, Culture, Sports, Science and Technology MOE Ministry of the Environment NISA Nuclear and Industrial Safety Agency (abolished) NSC Nuclear Safety Commission (abolished)#6NRA, Japan Nuclear Regulation Authority "Technical Independence" Report from OECD/NEA/CNRA, "The Characteristics of an Effective Nuclear Regulator", NEA/CNRA/R(2014)3 Utmost important elements for being effectively independent from undue influence in decision making: ■ Political independence ■ Authorized and being able to make independent regulatory judgments and regulatory decisions within their field of competence for routine work and in crisis situations. ... ■ Financial independence ■ Provided with sufficient financial resources, reliable funding and staffing for the proper and timely discharge of its assigned responsibilities. ... ■ "Technical independence" ■ Possess technical and scientific competence and the capacity to make independent decisions. Has access to independent scientific and technical support. 5#7NRA, Japan Nuclear Regulation Authority Merger of JNES with NRA ■ The former JNES was merged with NRA on March 1, 2014 to enhance the technical competence / expertise of NRA. ■ Regulatory Standard and Research Department (S/NRA/R) consisting of mostly research engineers from JNES was created as "internal TSO" for: ■ Developing technical standards and guides, and ■ Conducting safety research. ■ Cooperation with NSRC (Nuclear Safety Research Center) in JAEA and NIRS (National Institute for Radiological Sciences), "external TSOs" for NRA, has been strengthened. ■ NRA succeeds basically all the international cooperative activities through the IAEA, OECD/NEA, ETSON, etc. or bilateral agreements which the former JNES had participated in. 6#8NRA, Japan Nuclear Regulation Authority Basic Policies Set out in Major Acts Amended in June 2012 Basic Act for Atomic Energy ■ Safety objective was stipulated in Article 2: IAEA SF-1 To protect people's lives, health and property, and the environment, and to contribute to security taking into account established international standards Nuclear Regulation Act IAEA Safety Standards, etc. ■ Mandatory severe accidents measures Back-fitting to existing plants ■ Licensee's primary responsibility for safety ■ Limit of operation of 40 years for NPPs with possible extension up to 20 years just once ■ Special regulation applied to disaster-experienced plant (Fukushima Daiichi), etc. 7 http://www.nsr.go.jp/english/library/data/related_act_140301-02.pdf#98 (Severe Accident Measures) NEW Reinforced Reinforced NRA, Japan Nuclear Regulation Authority New Regulatory Requirements: Requirements for B-DBA ■ DEC: Design extension Structure conditions defined in IAEA SSR-2/1 4th Layer of DiD <Pre-existed> Natural phenomena 3rd Layer of DiD Fire Reliability Reliability of power supply Ultimate heat sink Function of other SCCs Seismic/Tsunami resistance <New> Suppression of radioactive materials dispersal Specialized Safety Facility Prevention of CV failure Prevention of core damage Natural phenomena Fire Reliability Reliability of power supply Ultimate heat sink Function of other SCCs Seismic/Tsunami resistance#10NRA, Japan Nuclear Regulation Authority New Regulatory Requirements: Enhanced Measures against Tsunami More Stringent Standards on Tsunami Enlarged Application of Higher Seismic Resistance It is required to define "design basis tsunami" that exceeds the largest in the historical records and to take protective measures such as breakwater wall based on it. 9 SSCs for tsunami protective measures are classified as Class S equivalent to RPV etc. of seismic design importance classification. Example of protective measures against tsunami (multiple measures) ■ Breakwater wall for prevention of inundation to the site ■ Tsunami gate for prevention of water penetration into the building http://www.nsr.go.jp/english/data/20130313presen.pdf#11NRA, Japan Nuclear Regulation Authority New Regulatory Requirements: Measures against Extreme Natural Phenomena ■ In order to prevent common cause failure, it is required to take measures against volcano eruption, tornadoes and forest fire, postulating severe conditions. ■ Example: Review Guide for Impacts of Phenomena ■ Assess the possibility that "severe volcanic phenomena which design cannot cope with" reach to the site during the plant life. Even if the possibility is small, it is required to conduct monitoring and develop policy on reactor shutdown, fuel unloading, etc. when volcanic unrest is identified. IAEA SSG-21 "Volcanic Hazards in Site Evaluation” gave us valuable inputs. 10 Radius 160 km 白山 A FREE NPP Pyroclastic flows at Mayon Volcano Philippines, 1984 http://en.wikipedia.org/wiki/File:Pyroclastic_flows_at_Mayon_Volcano.jpg#12NRA, Japan Nuclear Regulation Authority New Regulatory Requirements: Measures against Intentional Aircraft Crash, etc. Mountain side Emergency control Power supply room 11 "Specialized Safety Facility" is required to mitigate release of radioactive materials after core damage due to intentional aircraft crash. Specialized Safety Facility CV spray pump CV spray 0 Water source Molten core Water injection ☑into reactor cooling pump Core CV Reactor Filtered building venting * For example, 100 m Water injection into lower part of CV Filter sea System configuration is an example. For BWR, one filtered venting for prevention of containment failure and another filtered venting of Specialized Safety Facility are acceptable solution.#13NRA, Japan Nuclear Regulation Authority Focus in Safety Research ■ Special emphasis on external / internal hazards leading to large scale common cause failure: Extreme natural phenomena: - - Hazard curves of earthquake/tsunami, fragilities of SSCs Monitoring of volcanic unrests, ... ■ PRA methods and models: External/internal fire and floods, multi-hazards, multi-units, application of level 3 PRA ■ Research on Severe Accidents (SAS): ... ■ Code development for SA progression / source terms, .. ■ Experiments on scrubbing, seawater injection, SFP LOCA ■Research on Fukushima Daiichi: ■ Management of wastes/contaminated water, risk assessment ■ Criticality of fuel debris, etc. Other areas: ■ Decommissioning/waste Disposal, fuel cycle facilities, ... 12#14NRA, Japan Nuclear Regulation Authority Analysis of Fukushima-Daiichi Accident: SA Progression and Source Terms Background: ■ JNES started the accident analysis with MELCOR soon after the accident. ■ By using the source terms with MELCOR, an environmental consequence analysis was done in JAEA. ■ S/NRA/R is participating in OECD/NEA BSAF Project. Recent Development: ■ Based on the MELCOR results, CFD (Computational Fluid Dynamics) calculation for inside the containment is being done to study the containment failure mechanism and location at Unit 1. (K) 7.20e+02 7.00e+02 6.80e+02 6.60e+02 6.40e+02 6.20e+02 6.00e+02 Concentration of Cs 137 insol 1000円 1000-1000 100-1000 100-000 100-300 00-100 30-00 10 30 10 FUM 3000 89 M. Hirano, Presented at U.S.NRC RIC2014. (m/s) 5.00e+00 4.75e+00 4.50e+00 4.25e+00 4.00e+00 3.750+00 3.50e+00 3.25e+00 3.00e+00 5.80e+02 2.75e+00 2.50e+00 5.60e+02 2.25e+00 5.40e+02 2.00e+00 1.75e+00 5.20e+02 1.50e+00 5.00e+02 1.25e+00 1.00e+00 4.80e+02 7.50e-01 5.00e-01 4.60e+02 2.50e-01 4.40e+02 4.20e+02 4.00e+02 3.80e+02 3.60e+02 3.40e+02 0.00e+00 13 Cs-137 Concentration measured by MEXT (Nov. 5, 2011) (Bq/m²) 3000k< 1000k-3000k 600k - 1000k 300k 600k 100k-300k 60k-100k 30k-60k 10k-30k 10k were not obtained Cylinder Sphere Steam leak from RPV to CV is assumed to occur 5.4 hours after shutdown at gasket of SRV flange.#15NRA, Japan Nuclear Regulation Authority Research on Extreme Natural Hazards: Tsunami Hazard evaluation: ■ For 2011 Tohoku Earthquake, JNES developed a tsunami source model. By generalizing this model, S/NRA/R is developing a probabilistic tsunami hazard evaluation method. Fragility data accumulation: S/NRA/R is conducting the tests on impact on seawall due to tsunami. Large Scale Channel Test: 184m x 3.5m (12m in depth) 10.2m 01.2m 1.1m O Ο Measurement По O O : Acceleration : Wave pressure Ο O O Model seawall Model Seawall (1/10 Scale) 1.1m x 1.2m x 0.2m 津波高(m】 8.0 6.0 4.0 20 0.0 -2.0 -4.0 -6.0 1450 1500 15:10 1320 15:30 15:40 1550 trench 海溝 submerging plate Slips in sub-fault in JNES source model (Inversion analysis) 14 ■ The tests are being done at PARI (Port and Airport Research Institute). The data obtained are expected to be used for updating the review guides for design against tsunami.#16NRA, Japan Nuclear Regulation Authority Current Status of Fukushima Daiichi 15#17NRA, Japan Nuclear Regulation Authority Mid-and-Long-Term Roadmap towards Decommissioning ■ In Feb., 2013, the Nuclear Emergency Response Headquarters of the government established the Council for Decommissioning of TEPCO's Fukushima Daiichi NPS" (Chairman: Minister of Economy, Trade and Industry). In June 2013, the Council revised the Mid-and-Long-Term Roadmap*: December 2013 First half of FY2020 (one-and-a-half years earlier than the initial plan) at earliest 16 30 to 40 years December 2011 (Roadmap established) Efforts to stabilize the NPS <Cold shutdown achieved> •Achieve cold shutdown Significantly reduce radiation releases Phase 1 Period up to the commencement of removal of fuel from SFP (within 2 years) Source below, edited by the author December 2021 in the future Phase 2 Period up to the commencement of the removal of the fuel debris (within 10 years) Phase 3 Period up to the completion of decommissioning measures (30 to 40 years in the future) * Mid-and-Long-Term Roadmap towards the Decommissioning of TEPCO's Fukushima Daiichi Nuclear Power Station Units 1-4 Source: http://www.meti.go.jp/english/press/2013/pdf/0627_01a.pdf#18NRA, Japan Nuclear Regulation Authority Fuel Removal from Spent Fuel Pools Removal of fuel in Unit 4 SFP started on Nov. 18, 2013 and is planned to be completed until end of 2014. Number of fuel assemblies transferred to common pool: 1254/1533 (More than 75% as of Sep. 29, 2014) ■ In Unit 3, preparatory works are in progress for installing a cover for fuel removal. Unit 4 Cover (or container) Overhead crane Unit 3 Rainwater prevention measures (Protection) 17 Fuel-handling machine Crane Measures for rainwater infiltration North Fuel Exchanger Reactor Building Cover for fuel removal Transportation container Spent fuel pool North Transfer Installation of cover for fuel removal http://www.tepco.co.jp/nu/fukushima-np/removal4u/index-j.html Removal Cover for fuel removal#19NRA, Japan 18 Nuclear Regulation Authority Rubble Removal from Unit 3 R/B March24, 2011 遮へい体設置済み 4/4~4/7 April 19, 2014 14/02/35 PM01:03:55 February21, 2012 February25, 2014 Photo taken by TEPCO#20NRA, Japan Nuclear Regulation Authority Contaminated Water Issue at Fukushima Daiichi ■ Contaminated water in T/Bs is treated and injected back to RPVs. ■ App. 400m³/day of groundwater is intruding into TBS and it forces the capacity of tanks increase. App. 720 m³/day Reactor building Reactor cooling water injection: App. 320 m³/day Turbine Building(T/B) 19 Groundwater inflow: App. 400 m³/day Injection tank Water Surplus water: Reuse Desalination equipment App. 400 m³/day generated http://www.iaea.org/ Edited by the author Medium-to low-level tanks tanks Cesium removal devices App. 720 m³ /day Test operation currently conducted Advanced Liquid Processing system (ALPS) Main process building High-temperature Incinerator building (Temporary storage) (1) Areva (France) <Standby> (2) Kurion (USA) <Used as backup> (3) SARRY (Toshiba) <Used for normal operation> Water storage tanks#21NRA, Japan Nuclear Regulation Authority 3 Storage Tanks ■ 503,000 m³ of various levels of radioactive water is stored in the storage tanks. 3 387,000 m³ out of the total volume is ẞ and low-level Cs water that was treated with reverse osmosis (RO) membrane. It is stored in steel-made cylindrical storage tanks with flange. [July.8] Cylindrical storage tanks No.3 Square-shaped storage tanks Horizontal-installation- type storage tanks http://www.iaea.org/ Edited by NRA 20#22NRA, Japan Nuclear Regulation Authority Enhancement of ALPS Capacity 21 Multi-Nuclide Removal Equipment (ALPS): ■ ALPS aims to reduce the radioactivity levels of 62 nuclides in contaminated water to the legal release limit or lower (tritium cannot be removed) to reduce the risk. 750m³/day >500m³/day 1 Duplex stainless enameling grade steel ■ The second ALPS and advanced ALPS are being installed by TEPCO as well as a subsidy project of the Japanese Current ALPS ALPS #2 Advanced ALPS Capacity >750m³/day Number of 3 3 systems Improvement of corrosion resistance SUS316L Enameling grade steel Pretreatment Facility size Flocculation & precipitation 60mx60m Flocculation & precipitation (app.) Expected in- 2013.3.31~ (2014.10~) (2014.10~) Source: TEPCO Service Date 80mx60m Filtration 76mx36m government. http://www.tepco.co.jp/en/nu/fukushima- np/roadmap/images/d140828_01-e.pdf#23NRA, Japan Nuclear Regulation Authority Groundwater Bypass ■ In May 2014, TEPCO started "Groundwater Bypass" to reduce the amount of groundwater intrusion. ■ Groundwater is pumped up from the wells upstream of T/Bs and stored in the storage tanks and is released to the sea after confirming that the radioactivity concentrations are lower than the prescribed criteria. 2. Transport to storage tanks 3. Monitoring of Radioactivity 1. Pumping up from the wells Operational Rule: Cs-134: less than 1 Bq/L Cs-137 less than 1 Bq/L Total ẞ less than 5 Bq/L H-3 less than 1,500 Bq/L The sum of each ratio of 22 prescribed concentration limit: 0.22 汲み上げ Turbine building タンク Reactor building Hill 4. Release side Sea side Groundwater flow App. 150 m³/day reduction of groundwater intrusion is expected. Sea 揚水井 Source TEPCO, Edited by the author#24NRA, Japan Nuclear Regulation Authority Frozen Soil Wall Report from the Committee on Measures related to Contaminated Water Treatment, The Council for the Decommissioning of TEPCO's Fukushima Daiichi Nuclear Power Plant Frozen soil wall: ■ Implement the ducts in the ground with soil a pitch of, e.g. 1m, and circulate coolant. Frozen ■Construction already started in June 2014 and the freezing operation is Duct expected to start within FY2014. Circulation of Coolant Ducts for circulating coolant Source below, edited by the author: Frozen soil http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/t130627_11-j.pdf http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/images/d140627_01-e.pdf 23 A Sea Frozen soil wall Gross length: 1400m Fukushima Daiichi NPS Units 1-4 Hill-side#25N NRA, Japan Nuclear Regulation Authority Contaminated Water Remaining in Trenches ■ Highly contaminated water remains in the main trenches in seaside area. Contaminated water is flowing in from T/Bs. ■ TEPCO attempts to drain the water after plugging the flow paths by using the similar technique to that to be used for frozen ice wall. Shaft B Tunnel A Planned freezing point Ice plugging 3 2 O.P.+10m Trench B Shaft C Trench C Tunnel B Tunnel B Unit 2 seawater pipe trench Shaft A Freezing operation since April 27 Shaft D Mobile treatment equipment Tunnel A Unit 3 seawater pipe trench Trench A Trench D Turbine Building Shaft Cable tray Grouting OP+7.4m Water level O.P. +3m Shaft T/B Unit-2 Freezing operation since June 13 Drilling in progress T/B Unit-3 Main trenches and ice plugging operation Source TEPCO, edited by the author: http://www.tepco.co.jp/en/nu/fukushima-np/roadmap/images/d140627_01-e.pdf duct 3 Tunnel 2 Schematic of main trench at Unit 2 Source TEPCO, edited by the author: http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/t130627_11-j.pdf 24#26NRA, Japan Nuclear Regulation Authority Summary ■ Based on the lessons learned from the Fukushima Daiichi accident, the NRA was created as an independent and integrated regulatory body. ■ Since nuclear safety/security are to a great extent scientific in nature, "Technical Independence" is of utmost importance for regulatory decision-making. ■ The "Diet's report", for example, pointed out that "lack of expertise" is one of the fundamental causes of the accident. ■ JNES was merged with NRA to enhance the technical expertise and "S/NRA/R," an internal TSO, was created. ■ Regarding Fukushima Daiichi, various activities such as fuel removal from SFP are in progress according to "Mid-and- Long-Term Roadmap towards Decommissioning". Large amount of radioactive water being created daily is a difficult issue that needs long-term efforts. ■ Currently, removal of highly radioactive water reaming in the trench is a high priority issue. 25#27NRA, Japan Nuclear Regulation Authority Challenges as a TSO ■ TSO needs to timely contribute to resolving regulatory issues with high priority and, at the same time, be vigilant and proactive to new findings / emerging future needs. Effective Safety Research plays a key role. ■ Maintaining "technical infrastructure" is a challenge. ■ Continuous recruiting / developing skilled research engineers, ■ Maintaining test facilities, hot laboratories, etc. ■ Glowing needs for natural sciences such as seismology, meteorology, volcanology, etc. TSO needs to have an "interface function" with natural scientists in academia, etc. ■ International information exchange and joint research projects in IAEA, OECD/NEA, ETSON, etc. are playing an essential role. ■ Communication between regulatory body and industries on research be promoted while taking into due account of regulatory independence. 26#28NRA, Japan Nuclear Regulation Authority Appendix New Regulatory Requirements: Basic Policy ■ Place emphasis on Defense-in-Depth (DID) ■ Prepare multi-layered protective measures and, for each layer, achieve the objective only in that layer regardless of the measures in the other layers. ■ Eliminate common cause failures ■ Strengthen fire protection and measures against tsunami inundation. ■ Enhanced reliability of SSCs important to safety (eliminate shared use of passive components, if relied on for a long time). ■ Assess and enhance protective measures against extreme natural hazards ■ Introduce conservative/robust approaches in assessment of earthquake and tsunami and measures against tsunami inundation. Make much account of "diversity" and "independence", shifting from "redundancy centered". ■ Define "performance/functional" requirements ■ Provide flexibility in choosing acceptable measures. 27#29NRA, Japan Nuclear Regulation Authority Appendix Fire Safety Research on HEAF: High Energy Arcing Fault ■ At Onagawa-1, fire took place due to short circuit inside MC during the 2011 Tohoku Earthquake. ■ High energy gas generated by arcing fire was propagated to the other cabinets through the control cable duct. ■ In 2012, JNES started HEAF tests at U.S. KEMA and S/NRA/R continues them. HEAF simulation Test at KEMA in U.S. 28 No. 8 cabinet Source: Tohoku Electric Power, May 2011, http://www.nsr.go.jp/archive/nisa/earthquake/files/hou koku230530-2.pdf ■Currently, S/NRA/R is actively participating in the OECD/NEA international joint projects, PRISME-2 and HEAF. ■The acquired data have been used for developing the Review Guides for Fire Protection and Fire Hazard Analysis for the new regulatory requirements.#30NRA, Japan Nuclear Regulation Authority Experimental Study on Appendix Seawater and Boric Acid Injection We conducting a study on seawater/boric acid injection to identify the salt and boric acid crystallization/precipitation characteristics and its influence on fuel/debris cooling such as flow blockage for improving AM measures. Test for precipitation Seawater/boric acid at core solution tank Downcomer Online sampling needles Separator Spacer IAI Salt precipitation area 0000 6000 0000 00000 29 Pre-heater 介 Seawater/boric acid boiling loop Spacer 6x6 mockup bundle Appearance of salt crystallization in a preliminary test with simple geometry Preliminary test with bundle Vertical- sectional Cross-sectional view at TAF- 15mm view