Improvement of Irradiation Capability in the Experimental Fast Reactor Joyo

Transcription

1 IAEA Technical Meeting November, 2008 Improvement of Irradiation Capability in the Experimental Fast Reactor Joyo Tomonori Soga Fast Reactor Technology Section Experimental Fast Reactor Department O-arai Research and Development Center Japan Atomic Energy Agency 1

2 Oarai Research and Development Center Japan Materials Testing Reactor (JMTR) Fuels Monitoring Facility (FMF) Joyo Alpha Gamma Facility(AGF) O-arai R&D center MONJU Head Office & Tokai center AG F High Temperature Test Reactor (HTTR) JMT R ナトリウム技術開発施設 Sodium Engineering Facility Tokyo Office 2

3 History of Joyo JOYO Design Groundbreaking The first criticality achieved at Joyo The 1st criticality Mark-Ⅰ Mark-Ⅱ Modification works The 1st criticality 3 3 Mark-Ⅲ

4 Upgrading of the Joyo cores Mark-I core 50/75MWt Control rod Core fuel subassembly Reflector Blanket fuel subassembly Mark-II core Mark-III core 100MWt Subassembly for irradiation Shielding subassembly Inner core fuel subassembly Outer core fuel subassembly 140MWt MK- ⅢCore MK-ⅡCore Row Max. No. of Driver Fuel S/A 85 Max. No. of Test Fuel S/A 21 Core Diameter 80 cm Core Height Neutron Flux(> (>0.1MeV)( )(n/cm 2 s) ~16/21 wt% 420 W/cm cm 235 U Enrichment ~18 wt% Pu Content Total Major specifications (MK-III) Fissile(Inner/Outer) Max. Linear Heat Rate <30 wt% 6

5 Irradiation test experiences in the MK-III core Year Operation P erforman ce Test 3 rd 1 st 4 th 2 nd 5 th 6 th cy. 3 rd 15 th Periodical Inspection 4 th 5 th 6 th cy. MARICO-2 (ODS In-pile Creep Te st) ODS Claddin g M ateria l Ir ra diation Test Am, Np Bearing Oxide Fuel Ir radiation Test Fuel Failure Detection Testing (FFDL) 1/11 5/20 Ferritic W rapper Tube Fuel Ir radiation Test S AS S Ho ld in g S tability Te st 12/5 S AS S E le m ent Ir ra dia tion Test 4/26 Mate rial Ir ra dia tion Test (Fusion Reacto r, etc) 5

6 Test for FBR safety (Development of SASS) The Self Actuated Shutdown System (SASS) using temperature sensitive magnetic material has been developed as an innovative reactor safety system. (1) The holding stability test to demonstrate control rod holding ability by means of curie point electromagnet (CPEM) (1 st cy-2 nd cy). (2) The element irradiation test provides basic magnetic characteristics data under the irradiation.(3 rd cy-6 th cy) SASS is expected to enhance the reliability of fast reactor shutdown system. SASS Element Irradiation Test SASS Component Holding Stability Test 3000 CPEM for Large Scale FBR CR drop Upper Core Structure Rig Irradiation Container Electromagnet Separation Plane Holding Force (N) CPEM of SASS experimental equipment Weight of CR for Large Scale FBR (approximately 75kg) Weight of Simulated CR (approximately 30kg) Temperature (deg-c) Dummy Control Rod Temperature Sensitive Alloy : 30%Ni-32%Co-Fe Characteristics of CPEM 6

7 Type-I (Am-MOX) Fuel pellet Diameter: 6.52mm O/M : 1.95, 1.98 Density: 93%T.D. Pu: 30% Am: 3%, 5% Cladding tube Diameter: 7.5mm Type I Irradiation test of fuel containing minor actinide(ma) Type-II (Np/Am-MOX) Fuel pellet Diameter: 5.42mm O/M : 1.95, 1.98 Density: 93%T.D. Pu: 30% Np: 2% + Am: 2% Cladding tube Diameter: 6.5 mm Short-term test Lineup 5%Am 3%Am Cladding Upper end plug 200mm 200mm Core mid-plane Cladding 2%Am+ 2%Np MOX All fresh test pins Dummy Dummy Lower end plug Type II B11(1) (10min.) B11(2) (24hr.) Type I Type-II 7

8 Reactor Power History of B11(1) & B11(2) 120 MWt B11(1) 10 min. 12 MWt/h 60 MWt NIS Calibration 35 MWt Manual shut down Max:119.6 MWt Key Points 1. Maximum Reactor Power was determined at 120MW to set linear heat rate of test fuel pin at about 430 W/cm. 2. Reactor power was raised continuously and held at 119 MW about 10 minutes. 120 MWt B11(2) 24 hours 60 MWt 35 MWt 12 MWt/h Max:119.6 MWt Ave:117.8 MWt 8

9 In-pile creep test of ODS steel using Material Testing Rig with Temperature Control (MARICO-2) Gas Gap (He + Ar) In-pile creep rupture specimen Thermocouple A A Capsule Gas Inlet Line Gas Exhaust Line Capsule temperature controlled by adjusting gas composition A-A Section 24 ODS specimens were prepared which is pressurized by He. Xe and Kr (tagging gas) was enclosed along with the He gas. 3 rd - 6 th cycles, 14 ODS specimens have ruptured. (All were identified by tag gases.) Structure of MARICO-2 The MARICO-2 test was completed at 6 th operational cycle. 9

10 駆動部 Drive mechanism Structure of MARICO-2 MARICO : MAterial testing RIg with temperature COntrol MARICO-2 Drive Mechanism Sodium Outlet Rotating Plug Gas Gap Upper Core Structure Specimen Guide Tube 保持部 Holding Mechanism Guide Tube Joyo Reactor Hold Down Shaft In-vessel Storage Rack Core Sodium Inlet Gas Inlet Gas Outlet Gas Tube Test Subassembly Gas Tube Specimen A A Capsule Thermocouple Specimen Test subassembly 試料部 A-A Section Capsule 10

11 An Obstacle around In-Vessel Storage Rack On June 11th 2007, fuel handling machine was set up on the rotation plug (R/P) as a refueling preparation. While the jack down of R/Ps was doing, the measured load of hold down shaft indicated abnormal decrease. It was suspected that there is an obstacle under the hold down shaft. The in-vessel storage rack under the hold down shaft stored the MARICO-2 test subassembly. An obstacle around in-vessel storage rack was later identified as MARICO-2 test subassembly by the visual observations. JAEA ORDC Experimental 11 Fast Reactor

12 R/V Internal Structures Pipe of auxiliary cooling system Upper Core Structure (UCS) Hold Down Shaft In-vessel Storage Rack 12

13 Visual Inspection Devices In-Vessel Inspection Hole(A) In-Vessel Inspection Hole(B) Visual Inspection Device (Fiberscope) Camera Camera Flashlight Light Source Camera type Visual Inspection through the Fuel Handling Hole Fiberscope type Fiberscope Visual Inspection through the In-vessel Inspection Hole(A) 13

14 3D Image of Obstacle in the Reactor Vessel Visual Inspection Device Hold Down Shaft Lower Part of UCS Top of Subassembly MARICO-2 Test S/A 14

15 Expansion of irradiation condition high VHTR, Gas cooled reactor Fusion reactor High temperature field Temperature MA,LLFP transmutation RI production Irradiation effect research Neutron moderation GFR SFR low LWR (Upgrading, Life-extension) Low temperature field Spectrum and temperature tailoring according to research purpose low Neutron energy or dpa high 15

16 Concept of neutron spectrum tailoring Driver Fuel Shielding S/A Reflector (SUS) Moderator Target Be, 11 B 4 C, ZrH 1.65 N e u tro n flu x (n /c m 2 s /L e th a g y) ZrH 1.65 (Volume fraction 30%) Be (Volume fraction 90%) Reflector (stainless steel) Fuel region Reflector Total 9.2 (Unit :x10 14 n/cm 2 s) Neutron flux 0.1MeV keV 1.3 Be ZrH Neutron Energy (ev) 16

17 Transmutation rate of 99 Tc and 129 at the core mid-plane 129 I Fractional transmutation rate (unit: %/yr) 99 Tc 129 I Rad. reflector Be (90%) ZrH 1.65 (30%) ZrH 1.65 (60%) Core region

18 Lowering coolant temperature At 370 deg-c, 2x10 15 n/cm 2 s can be obtained. Inlet Outlet Core Distance from Core Center (mm) Inlet Temp. 350 deg-c Inlet Temp. 290 deg-c x10 15 Fuel Region 18 Inlet Na Temperature deg-c E E E Coolant Temp. (deg-c) Fast Neutron Flux (x10 15 n/cm 2 s)

19 The irradiation rig and high temperature irradiation capsule Height (mm) Temperature ( o C) Outer tube (stainless steel) Insulation gas gap (Ar-He mixture gas) Tungsten inner tube Irradiation specimen Compartment High temperature capsule For Gen-IV reactor(gfr, VHTR), fusion reactor Radius (mm) Calculated temperature distribution 19

20 Additional function for high-quality irradiation test - Computerized reactor control system by automatic control rod operation to accurate irradiation test - Sample movable device for flexible transient test - Fast neutron beam hole for short-term term irradiation test or short-lived RI production. 20

21 Computerized reactor control system by automatic control rod operation Manual reactor operation 6 control rods are regularly pulled out by operators to compensate for the reactivity loss with the fuel burn-up. (3 time / day) These operations influence the irradiation temperature of the specimen. REACTOR POWER(MWt) Reactor power Temperature (MARICO thermocouple) 10 days Automatic reactor operation -To keep the reactor power constant without relying on the frequent manual operations. -To reduce the operator s burden in case of conducting the transient tests as precisely as planned. Control rod The automatic control rod operation system has been newly licensed. 21

22 Concept of sample movable device To change linear power and neutron flux in a short time by axial movement of sample 100 Distance from the core center (cm) times Core center Moving range( +90cm to -25cm) φf( 0.1MeV) (n/cm 2 s) Linear power (W/cm) 22

23 Ar Gas Core Na Rotating Plug Fast neutron beam hole To achieve the short term irradiation without restriction of the operational cycle (60day). 800 Test specimen x10 9 Rotating Plug Rotating plug Core 1E+04 1E+06 1E+08 1E+10 1E+12 1E+14 1E+16 Axial Position (cm) 0 4x10 15 Core Ar gas Na Fast Neutron Flux(>0.1MeV) (n/cm 2 s)

24 Summary Joyo MK-III core is utilized as high fast neutron irradiation test bed. Main primary mission of this reactor is to support R&D for FBR in Japan. Several upgrading programs are being promoted to pioneer new irradiation testing applications for not only FBR but also other various R&D fields. The licenses for the computerized reactor control system, neutron spectrum tailoring and lowering coolant temperature have already been permitted, and the design work of all the concepts has started. 24 These improvements of irradiation capability are expected to promote international collaborations and utilization by external users through sharing the infrastructure for high-quality irradiation tests.