R&D on Fast Reactor Cycles and Role of Monju and Joyo

Transcription

1 International Symposium on Present Status and Future Perspective for Reducing Radioactive Wastes~ Challenge for the Relief in the Next-generation ~, Feb. 17, 2016, Tokyo R&D on Fast Reactor Cycles and Role of Monju and Joyo February 17, 2016 Director General, Advanced Fast Reactor Cycle System Research and Development Center, Sector of Fast Reactor Research and Development, Japan Atomic Energy Agency (JAEA) Hideki Kamide

2 Contents 1 Today s significance to hold fast reactor cycle technologies and the role of "Monju" in R&Ds Future planning of R&Ds Reflection of R&D results into the demonstration and commercialization R&D on Monju Safety enhancement of FBR / FR Development of demonstrated technologies of FBR / FR Development status of separation and transmutation technology that utilizes FBR / FR Situation for the irradiation test resumption of Joyo Direction of the fast reactor cycle R&Ds should be headed

3 Today s significance to hold fast reactor cycle technology 2 Efforts to make steadily progress without Postpone Spent fuel (SF) Problem Japan stores about 17,000 ton of SF. SF and radioactive wastes are generated continuously by the nuclear power generation and the decommissioning. Drastic strengthening of efforts to resolve the SF problem Efforts on final disposal of high-level radioactive wastes Expansion of the storage capacity of the SF Technology development for reducing the volume and radiotoxicity of radioactive wastes Promotion of the nuclear fuel cycle policy Promoting such as reprocessing and plutonium-use in LWR Effective use of recovered Pu, etc. (R&D on Nuclear fuel cycle, Fast reactors, etc.) Monju: aggregation of research results as an international research center Flexibility of medium- and long-term response (Uncertainty) Responding to sustainability and uncertainty The basic policy is to promote the nuclear fuel cycle. To ensure a wide range of choices for uncertainties in future is also important from the energy security in Japan. Holdings of fast reactor cycle technology is important. Contribution to Japan's energy security (effective utilization of uranium resources) Reduction of high-level radioactive waste (HLW) generated (environmental load reduction) Step-by-step R&D using "Joyo", "Monju", etc. is essential.

4 Features of the Fast Reactor (FR) Cycle 3 Efficient use of Resources The use of Pu enables Energy Independence without depending on overseas Uranium resources Deployment of FBR allows the U use of more than a thousand years. U resource reserves are about 100 years depending on nuclear power generation. A steady R&D of FR Cycle is required. The development takes a long time. Eco-friendly Reduce the amount of HLW by reprocessing SF and vitrifying HLW. Higher reduction efficiency by Shifting to the FR Cycle High thermal efficiency of Power Generation Lower heat generation of vitrified wastes by removing Minor Actinides. Effective use of uranium resources Reduction of environmental impact Number of years until used up uranium resources Several thousand years -100 years In the case of LWR use In the case of FBR use Source:JAEA made by using the Uranium 2009: Resources, Production and Demand. Volume of HLW per unit power generation (relative value) LWR SF <Reduction of generated wastes> LWR Reprocessing (Vitrified waste) volume decreases to one-seventh FR Reprocessing (Vitrified waste)

5 The role of "Monju" in R&D 4 Compilation of the R&D results of the FBR technology "Monju is a large-scale FBR power plant and aggregation of our country own technology. Know-how obtained by operating our own plant (design, manufacture, construction) is key. Reducing the waste volume and radio-toxicity Actual scale test is essential for Fuel Assembly. Full-scale irradiation test in Monju The world's first to obtain characteristics of Core with Am* in the entire region. Joyo Monju Am*: typical long-lived radionuclides in the waste CPF Reprocessing Fast Reactor (FR) Fuel development and irradiation tests Reactor characteristics/ rector system Evaluation of waste reduction by FR cycle PIE tests Fuel Fabrication FMF CPF AGF Pu-3 Safety technology system of FBR Safety Enhancement Monju is an actual plant to provide R&D field for Safety technology system of the entire FBR R&D in "Monju" Accident management measures in Severe Acci. Comprehensive safety evaluation by PSA SDC and SDG of Gen-IV reactors Prevention of re-criticality in CDA Diversification of stable cooling measures of a damaged reactor core fuel Implementation of the SA counter measures R&D outside of Monju Holdings of our own FBR technology (design, construction, operation, decommissioning)

6 Future Planning of R&Ds 5 The third period medium- and long-term planning" of JAEA reflecting Strategic Energy Plan and the "Monju Research Plan Promote the R&D on the following issues. R&D on Fast Rectors Monju Joyo R&D on Monju R&D towards the establishment of proven technology of FR Safety enhancement of FBR /FR Demonstration technology development through ASTRID cooperation R&D on Nuclear fuel cycle Reprocessing of SF and fuel fabrication Reducing the volume and potential radio-toxicity of radioactive wastes Development of test field for R&D Pu-3 fuel production facility Hot labo., PIE facilities Early release from the NRA s order on safety treatment Apply to NRA for permission to restart Test facilities related to Na, etc. Commercialization of MOX fuel production facility Response to the new regulatory regulation Consolidation of sodium test facility ASTRID Monju Joyo AtheNa facility

7 R&D for safety enhancement of FBR/ FR International development of safety design requirements National development of structural material specifications and standards and its reflection in international standards Core damage mitigation technology development Thermal-hydraulics analysis and evaluation methods development ASTRID cooperation R&D on Monju Core and fuel technology Equipment and systems design technology Sodium handling technology Plant operation and maintenance technology MA-bearing MOX fuel irradiation test Demonstrate natural circulation decay heat removal Reflection of R&D results into the demonstration and commercialization R&D for reduction of the waste volume and radiotoxicity Fuel fabrication Fuel development and irradiation test Reprocessing (separation technology) Reactor characteristics and reactor system The entire system evaluation Establishment of demonstration technology Next reactor design with international safety design requirements Analysis code, design approach Equipment design Certainty of design Confirmation of the safety margin Operation of next reactor Operational standards, operation and inspection procedure Maintenance and repair method Operation and maintenance policy (Inspection frequency, etc.) Feasibility confirmation of reduction of the waste volume and radiotoxicity Burnup theory demonstrated in the current Am-containing core Demonstration of MA-bearing fuel irradiation Optimum system concept Establishment of design technology Certainty of effectiveness Commercialized FBR cycle Reactor Fuel cycle plants 6

8 R&D on Monju 7 Aggregate the outcome of the FBR technology development including the technical feasibility of the FBR plant, and Reflect it in the next reactor design by utilizing "Monju of our own design, manufacturing, and construction. Aggregate of the fast breeder reactor technology Core and fuel technology Confirmation of higher isotopes of Pu core characteristics based on the actual reactor data. Equipment and system design technology Plant system design technology Design technology of large sodium equipment Sodium handling technology Development of in-service-inspection technology for the reactor vessel, etc. Plant operation and maintenance technology Establishment of a maintenance program in light of the characteristics of the FBR power plant, etc. R&D for reducing the waste volume and radiotoxicity Evaluate of the MA transmutation and the irradiation behavior by full-scale irradiation tests with MA-bearing MOX fuel, etc. Examples of specific reflections Core design approach and core management technology Reactor kinetic characterization and shielding evaluation methods Aging characteristics and Integrity of sodium equipment Na management techniques of loop-type FR power plant R&D of enhanced safety Demonstrate the decay heat removal in the actual plant as a feature of the sodium-cooled FR with natural circulation Irradiation test (X-ray CT image)

9 Global Standards for SFR SDC and SDG 8 Japan leads to build safety design requirements (safety design criteria (SDC) / guidelines (SDG)) toward the safety enhancement of SFR in the world. FR development countries intend to reflect them in their safety regulations and safety design. De facto global SDC&SDG Positioning and the purpose of SDC / SDG Global standardization of the safety design concepts toward the commercialization (mainly on design basis accidents) Safety improvement of FRs in the world by Japanese initiative Main results: SDC report (approved by GIF in May 2013) Review is in progress among regulatory bodies/technical support organizations of FR development countries and by international organizations (IAEA, OCED/NEA/CNRA, etc.) Russia, China, India etc. intend to reflect in the safe design <Hierarchy of Safety Standards> Safety Fundamentals SDC SDG Safety Requirements Design guides of the Reactor Coolant System and Associated Systems in Nuclear Power Plants Domestic Codes and Standards Targets of global standards

10 Status of ASTRID Collaboration 9 The French President and the Japanese Prime Minster agreed to collaborate on the development of the 4th Generation Reactors. General Agreement was signed on May 5, Implement Agreement was singed on August 7, ASTRID technologies Common issues Safety design Sodium technologies Fuel technologies Japanese SFR technologies Major progress Design and R&D on Safety enhancement including severe accident measures Design: Decay heat removal system, Shutdown system, Seismic isolation R&D: fuel, safety, and plant system Design and related outputs could be directly incorporated into the Japanese SFR development. R&D collaborations are on going through experiments and analysis methods.

11 Research projects of FR cycle technologies Improvement of the flexibility in Pu use, verification of MA partitioning and transmutation technologies, etc. are necessary for obtaining technological perspective on the reduction of the volume and radiotoxicity of radioactive wastes 10 CPF Reprocessing: Development of MA partitioning process and performance evaluation Establishment of feasible process concepts Comprehensive system evaluation: Integration of information in each area & narrowing prospective system concepts Verification of effects on reduction of the volume and radiotoxicity of radioactive wastes Monju Reactor Characteristics & Reactor system: Feasibility confirmation of FR plant technologies Acquisition of characteristics of MAcontaining core Joyo Spent MOX fuel FR Fuel Development & Irradiation Test: Systematic irradiation tests of MA-bearing MOX fuel, High Pu-contents MOX fuel Reprocessing Evaluation of volume reduction, etc. by utilization of FR cycle MA-bearing new MOX fuel FMF U, Pu, MA Fuel Fabrication AGF Pu-3 Fuel Fabrication: Remote MA-bearing MOX fuel fabrication technology Determination of fuel composition range applicable

12 Status of Technological Development for Partitioning and Transmutation of Long-lived Nuclide Utilizing FRs 11 Carry out a series of tests (from partitioning, recovery and conversion to fuel fabrication, irradiation and post irradiation examination) on MAs from spent fuel using existing facilities Partition MAs from liquid waste 多孔質シリカ吸着材の Particle diameter 写真 ( 寸法付 about 50μm ) とか SiO 2 -P Fine cross section Succeeded at absorptive partitioning of more than 99.9 % of MAs in HLW liquid Fabricate MA-bearing fuel pellets Sophistication of fuel fabrication technologies Microstructure and Am concentration (relative value) Pore diameter about 500nm 8 mm φ5.4 mm MA-bearing fuel pellet Microstructure Center 1mm High Am concentration at central (Temp. at center: about 2400 ) oxygen content control Acquisition of basic data & development of technology for fabrication condition optimization Irradiation tests of-ma bearing fuels at 2000 or higher Outer peripheral part of fuel pellet Evaluation of effects of MAs on fuel performance is necessary Effects of re-distribution behavior of MA under irradiation on physical properties (eg. melting point) Conditioned MA-bearing raw powder Irradiation Fuel Fabrication O-arai: AGF MA fuel for Irradiation Tests SmART Cycle Partitioning Tokai: CPF Irradiation Oarai: Joyo Spent fuel High-radioactive liquid waste (HLLW) LWR FR Irradiated MAbearing fuel Post Irradiation Experiments O-arai: FMF Monju Irradiated MA-bearing fuel (MA: minor actinide, Am: Americium, Cm: Curium)

13 MA separation technology using extraction chromatography 12 MA could be separated from genuine HLLW using extraction chromatography method which has been developed at JAEA. Extraction chromatography MA separation is achieved by flowing the feed with MA and eluent into the packed column of solid adsorbents. Advantages:Less secondary waste, compact equipment etc. Examples of extractant Extractant impregnation Organic polymer P O O CMPO SiO 2 Schematic of surface layer on adsorbent N SiO 2 -P adsorbent Porous silica covered stylene divinyl benzene polymer and impregnated extractant in the pore N N N SiO 2 -P adsorbent Grain size μm, Pore size nm N BTP N N N 1 st stage MA+RE separation (RE:Rare earth elements) Column Adsorption and elution 2 nd stage MA separation Adsorption and elution Feed Waste MA+RE Waste Eluent MA+RE Eluent MA C/C 0 C/C0 1 DV Feed 3M HNO 3 H 2 O 50mM DTPA (ph=3) MA+RE recovery Sr Pd Ru-106 Sb-125 Cs-137 Ce-144 Eu-155 Am-241 Cm-242 ph Through Bed Volume Chromatographic separation of genuine HLLW by the column with CMPO/SiO 2 -P adsorbents HLLW : high level liquid waste Feed 1 mol/dm 3 HNO 3 H 2 O Dead Vol. MA recovery Sr Zr Ba Ce Sm Gd Cm Through bed volume Chromatographic separation of real HLLW by the column with BTP/SiO 2 -P adsorbents MA separation results from HLLW (2-step separation) Y Mo La Nd Eu Am ph

14 Unified physical property model for fuel technologies 13 Basic properties and correlations have been studied, and a fundamental technology to control oxygen content in MA-bearing MOX was obtained. Development of an unified physical property model through property measurements, database construction and mechanistic relational equation derivation Development of fuel behavior models in fuel fabrication process and operation conditions based on the property model MOX granules Sintered MOX pellets U/Pu ratio adjustment in nitric acid solution Microwave heating de-nitration and granulation Pressing Sintering and O/M adjustment Products Oxygen content (O/M ratio) O/M ratio Experiment FAverage O/M ratio 1.98 Calculations JEquibrium O/M ratio KAverage O/M ratio 1.96 Chemical stability Oxygen diffusion Calculation examples by the correlations Oxygen control technology Apply to sintering condition Temperature Heat treatment time(h) Temperature ( o C) Calculation of oxygen content change in pellets during heat treatment Sintering condition for low oxygen content pellets

15 14 Irradiation performance of MA-bearing MOX fuel Slight increase in MA (Am) concentration near the center of the fuel pellet due to irradiation was confirmed from the result of the MA-bearing fuel irradiation experiment in Joyo. A computer analysis model was developed which could reproduce this phenomenon. Short-term and high linear heat rate (LHR) irradiation of MA-bearing MOX fuel pins Ceramography of irradiated MA-bearing MOX fuel pellet Center Am measurement Edge 1mm Change of Am concentration due to irradiation was calculated by using vapor phase and solid phase diffusion analysis models. Central void Irradiation in Joyo MA content of fuel pellet Am:~5wt% / Np:~2wt% Irradiation condition (LHR / period) ~450W/cm / ~24hr Center Edge Radial profile of Am concentration

16 Minor Actinide Transmutation in FRs 15 Fast reactor core concepts for MA transmutation were developed. When the high-burnup fuel is realized, 50-60% of initial MA load in fuel fabrication can be transmuted before fuel exchange. Basic characteristics of FRs for MA transmutation Items JSFR (Breeder) Pu-MA burner Electric output [MWe] Breeding ratio (Conversion ratio) Core height [cm] Fuel pin diameter [mm] Fuel lifetime [EFPD] Fuel burnups [GWd/t] MA content in heavy metal [wt%] Core layout of a Pu-MA burner Core height 75 cm Core equivalent diameter 3.3 m Linear heat rate [W/cm] Fuel subassembly Primary control rod Backup control rod 1 Transmutation of initial MA load 2 MA generation from core fuel

17 Development of ODS steel cladding tube 16 JAEA has developed the long lifetime oxide dispersion strengthened (ODS) steel cladding tube, which can double MA transmutation ratio compared with existing technology. The fabrication process was successfully developed to reliably produce high performance ODS steel tubes. ODS steel cladding tube Substantial swelling resistance Increasing burnup => High MA transmutation ratio, Reducing nuclear fuel costs Excellent mechanical strength at high temperature Increasing fuel lifetime, Safety enhancement High power generation efficiency produced by high outlet Na temperature Fuel performance improvement in terms of environmental, safety and economical aspects Recent progress: Fabrication technology development, which can reliably and consistently produce high strengthen ODS steel cladding tube Creep strength MA transmutation ratio (%) Swelling (vol.%) Evaluated MA transmutation ratio vs neutron dose, burnup Modified type 316 steel Ferritic steel, ODS steel twice Modified type 316SS Ferritic steel ODS steel Neutron dose (x10 26 n/m 2, E>0.1MeV) Average discharge burnup (GWd/t)

18 SmART cycle (Small Amount of Reuse Fuel Test Cycle) 17 JAEA promotes SmART cycle project which includes MA separation from irradiated fuels and irradiation of the MA-MOX products in Joyo for the first time. Preparation of HLLW was completed to get MA more than 1g. Objectives Separation and transmutation data of MA etc. Feasibility of small scale of partitioning and transmutation cycle Irradiation behavior of MA isotopes in the MOX fuel will be evaluated for the first time in the world. AGF (Oarai) Joyo (Oarai) Fuel fabrication Irradiation Denitration, conversion LWR, FBR Separation SmART cycle PIE Irradiated fuel CPF(Tokai) Significance Effect of FPs on fuel fabrication and irradiation Effect of MA isotopes on transmutation Material balance of MA through the cycle MA amounts MA more than 1g is separated from 4 pins of irradiated Joyo fuel MA yields recovered from irradiated fuel are top level in the world Current status Shearing, dissolution and extraction of irradiated Joyo fuel pins were completed. MA separation from the raffinate of extraction will be implemented hereafter.

19 For Restart of Irradiation Test Activities in Experimental FR Joyo 18 Completed the restoration work on the damaged experimental device that had been in trouble and brought Joyo back into recovered and normal state Plan to submit an application for permission of changes in reactor installation in FY2016 Plan to conduct irradiation tests, etc. related to R&D for reduction of the volume and radio-toxicity of radioactive wastes and for ASTRID project after the restart Completion of the restoration work on the damaged experimental device R&D for inspection and repair the interior of the reactor vessel at high dose (max. 300 Gy/h) and high temperature (~200 ) High radiation resistant fiber-scope, etc. Replacement of the large in-vessel component: Upper Core Structure (UCS) (~16.5 ton) Retrieval by using a remote device Temporary cradle Wire jack Cask Door valve May-Nov. 2014: Completed replacement of the UCS and retrieval of the experimental device June 2015: Completed the re-installment of the retrieved device; brought Joyo back into normal state Temporary pit cover Pull-out work of UCS

20 Direction of the fast reactor cycle R&Ds should be headed 19 At the time the policy towards the commercialization of FR cycle is embodied, the R&D should be steadily promoted in order to present the following achievements. Development of research infrastructure Early improvement and re-start of the test facilities such as Monju," "Joyo Development and accumulation of human resources and technology platform to support the FR cycle technology using "Monju," "Joyo, fuel cycle facilities, etc. R&D Confirmation of the technical feasibility of innovative technology that reflects the safety enhancement measures in light of the Fukushima Daiichi nuclear power station accident Establishment of FR reference plant concept incorporating international safety design requirements (SDC, SDG) Prospect of technical feasibility on reducing waste volume and its radiotoxicity Drawing the path to commercialization (technology roadmap), etc. In the implementation of the policy, promoting dialogue and information sharing with stakeholders, reflected in the direction of R&D To that end, along with promoting human resources development and technology transfer specifically, operate test facilities in the highest priority on safety by implementing the response to the new regulatory regulation ASAP.