Status of Compatibility Facilities and Experiments on LBE with CLEAR-I Structural Materials

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2 Status of Compatibility Facilities and Experiments on LBE with CLEAR-I Structural Materials Presented By Zhizhong JIANG Contributed by FDS Team Institute of Nuclear Energy Safety Technology Chinese Academy of Sciences (INEST) IWSMT-12 Bregenz

3 Outline Background Validation Strategy of CLEAR-I Materials Developments of Compatibility Facilities Recent Experiments on Materials in LBE Summary

4 China LEAd-based Reactor (CLERA) Project Chinese Academy of Sciences (CAS) has launched an ADS Project, and plan to construct demonstration ADS transmutation system ~ 2030s by three stages. Institute of Nuclear Energy Safety Technology (INEST. CAS) has taken up the China LEAd-based Reactor (CLEAR), it is selected as the reference reactor for ADS project.

5 Reactor Design Current Status of CLEAR-I Project 2011:Conceptual Design 2012:Detailed Conceptual Design 2013:Starting Preliminary Engineering Design Technical R&D 2011:PbBi Loop and Components Conceptual Design 2012:PbBi Loop Engineering Design and Fabrication 2013:PbBi Loop Construction and Components Fabrication Safety Analysis 2011:Safety characteristics evaluation and software development 2012:Software V&V 2013: Accident Analysis Design, Key R&D, Licensing to be completed around 2015 Construction to be started around

6 Characteristics of Liquid Pb-Bi Eutectic (LBE) Advantages Low moderating performance and low absorbing cross-section Excellent neutron properties, higher neutron flux for transmutation Good thermal conductivity, a lower operation temperature Low chemical activity, no fire with water and air, more safety As liquid metal spallation target, no radiation damage Special flow and heat transfer characteristics of LBE Challenges Compatibility of LBE with structural materials Special flow and heat transfer characteristics of LBE LBE is selected as coolant for CLEAR-I because of obvious advantages and success of LBE submarine in former Soviet Union

7 Outline Background Validation Strategy of CLEAR-I Materials Developments of Compatibility Facilities Recent Experiments on Materials in LBE Summary

8 Objectives Overall guidelines Supporting engineering design and construction Providing data of Safety Analysis Report (SAR) Principles Mature materials with practical experience in nuclear field Materials have referential data for sharing. Materials with excellent fabrication and machining performance CLEAR-I Materials selection for main structure contacting with LBE Components Temperature( ) Velocity(m/s) Materials Vessel and internals 280~400 < L Structural support 300~320 < L Heat exchanger 300~400 < L/T91 Cladding 400~492 < Ti/316Ti

9 R&D Program for Materials Validation Properties Difficulties Solutions Physical performance (specific heat, thermal conductivity, density ) none General properties (Without LBE) Mechanical performance (tensile impact fatigue ) none ASME or RCC-MRx Machining performance (welding forging ) none Service properties (In LBE) Liquid metal corrosion (LMC) Liquid metal embrittlement (LME) Thickness reduction Degradation of mechanical properties(tensile, creep, toughness, fatigue) Construction of facilities (to meet operating environment of reactor) KYLIN series loops Environmental devices International cooperation Irradiation & synergy with LBE Degradation of mechanical properties(tensile, creep, toughness, fatigue) Construction of Irradiation devices International cooperation

10 Technical challenges for materials validation There are no referential experiences for materials selection Although the typical materials had been selected based on traditional reactors and other LBE cooled reactors, the detailed requirements of material used in actual reactor, especially for compositions. Lack of sufficient data in LBE to support the availabilities of present materials selected. There are no mature standards for materials tested in LBE Significant scatter of the results in different labs, no agreed standards to judge the performance of materials, such as measurements of corrosion thickness, and displacement on samples in LBE. Impurity contents of LBE, which will affect the results of corrosion and mechanical properties, such as dissolved O, Ni, Cr, etc., Strengthening cooperation with designers, fuel, safety and coolant chemistry groups is crucial

11 Outline Background Validation Strategy of Materials for CLEAR-I Developments of Compatibility Facilities Recent Experiments on Materials in LBE Summary

12 China Liquid PbBi-Loop Technology Roadmap Three-steps for LBE technology KYLIN-II Thermal-hydraulic and Safety validation loop ( ) KYLIN-I Materials loop Materials and LBE technology Thermal-hydraulic loop test loop ( ) Thermal convection loop Forced convection loop Static/rotating Device Safety loop Key components Control technology validation KYLIN-III/CLEAR-S Reactor Core Integral experimental platform ( ) Integral Circulation Reactor Safety Reactor Operation and Control Series PbBi loops has been built to develop the LBE technology and support the construction of CLEAR.

13 Objectives Pre-research Loops of KYLIN Key technologies of large-scale loops Corrosion mechanisms and components of flow measurement and control Oxygen control and purification techologies Development Course 2010:the first thermal convention corrosion loop 2011:Pre-research loop for measurement and control of liquid metal, development of mechanical pump and electromagnetic pump 2012:Oxygen control system and oxygen sensors, small-scale corrosion device with OCS Thermal convention corrosion loop Corrosion device with OCS Pre-research loop for measurement and control of liquid metal

14 Materials Test Loop KYLIN-II-M Large Scale Platform for Material and Technology Test Parameters (1000 o C, 10m/s)covering research/demo/commercial reactors Key components assembling Reactor Materials and Component test Fuel cladding materials test Pumping and heat-exchanger test Mechanical properties under LBE condition LBE Conditioning Technology Gas/solid phase control technology Filtration and magnetic purification technology KYLIN-II (M) LBE oxygen control

15 Running Status of KYLIN II-M December, 2013 Temp.:500 Flow:1.69m 3 /h OC:none March, 2014 Temp.:550 Flow: 1.9m 3 /h OC:none April, 2014 Temp. :550 Flow: 1.9m 3 /h OC :10-6 wt% June-August, 2014 Final defects eliminating 550±5 Adjustment stage 1.9±0.2m 3 /h Satble stage After nearly a years of trials, the materials test had begun at 15 th October

16 Principal Directions Current Plan of KYLIN II-M Operating conditions of CLAR-I Requirements of Safety design Operating conditions of KYLIN-II-M Material Test Conditions Temperature:500 (492 ) Velocity: 1m/s (~0.8m/s. ~ 20% margin) Oxygen: wt% (temperature range of reactor, gap of PbO and Fe 3 O 4 thresholds ) logc o (wt%) PbO 生成限 -6-8 Fe 3 O 4 分解限 Temperature( ) 温度 ( ) Including four types specimens: 316L T Ti tube and CLAM

17 Facilities for Mechanical Tests in LBE Objectives Explore mechanisms of LME, SCC sensitivity Obtain Fatigue, Creep, Tensile properties in LBE with oxygen control Design Parameters Temperature up to 600 Static LBE Gas phase oxygen control SSRT facility Stress corrosion facility Creep facility Fatigue facility Facilities had been already in first half of this year, Fracture toughness facility is to designed and constructed next year

18 Outline Background Validation Strategies of Materials for CLEAR-I Developments of Compatibility Facilities Recent Experiments on Materials in LBE Summary

19 Corrosion Experiment without Oxygen Control m/s 316L: The thickness of oxide layer is very thin, and stripping phenomenon was found. 316L 316L T91: The oxide layers is thicker than 316L, and stripping was not found, but adhesive strength waslessdesirable. 1000h 1000h T h T h

20 Corrosion experiment Experiment results with with Oxygen oxygen Control control Oxidation, Co=10-6 wt% Dissolution, Co=10-8 wt% 316L T91 316L T m/s 1500h 316L: Single oxide layer, about 2 ; (Fe, Cr) 3 O 4. T91:double-layer structure, about 18 ; The outer layer:fe 3 O 4, about 6 ; The inner layer: ( Fe, Cr)3O4, about m/s 600h 316L: Severe dissolution corrosion; Maximum LBE penetration depth~100 ; T91: Slight dissolution corrosion; Maximum LBE penetration depth~30 ;

21 Wetting (LBE-T91/316L Pb-T91) Measurement of contact angles Capturing photos Calculating Microstructure examination Bi Pb The contact angles both LBE-T91 and LBE-316L were larger than 90, and the contact angle of LBE-316L was slight larger than LBE-T91 that of at the same temperature; The addition of Bi into Pb reduced the wetting of LBE-T91, which might be caused by the surface segregation Bi atoms.

22 Tensile Properties (LBE-T91) Testing device Parameter Temperature Autoclave material Cover gas 600 T %Ar Strain rate 10-7 ~10-1 s -1 Specimen Ф4 20mm 3 Experiment and results Static LBE without OCS, 200~400, 10-5 s -1 The effect of LBE on strength and ductility of T91 was not significant; Cracks were detected on the surface 350 of the necked region; The tensile propperties of 316L in LBE will be conducted in the next work.

23 Specimens Stress Corrosion Behavior (LBE-T91) 0MPa 1500h oxide layer D Main results f D D hoop stress d 2 D 4 EtZ 150MPa 1500h 300MPa 1500h T91 resin 480,Static LBE without OCS No cracks were detected on the surface of all T91 specimens, which caused by a barrier between T91 and LBE formed by the duplex structure oxide layer on the surface of T91; Stress accelerated the growth of the both layers, especially for the outer layer.

24 Outline Background Validation strategies of materials for CLEAR-I Developments of Compatibility Facilities Recent experiments on materials in LBE Summary

25 Summary Main structural materials of CLEAR-I had been selected, KYLIN-II loop and facilities of mechanical testing in LBE is now ready for operation. Basic fundamental researches on mechanisms of corrosion and LME effects had been started, further studies will need more careful exploration. Materials validation is a very complex project, welcome international colleagues to join and share experiences for CLEAR-I construction

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