Fabrication and Evaluation of SFR Cladding Tubes

Transcription

1 International Conference on Fast Reactors and Related Fuel Cycles 2013, Paris, France Fabrication and Evaluation of SFR Cladding Tubes Sung Ho Kim, J.H. Baek, J.H. Kim, C.B. Lee Next Generation Fuel Development Division Korea Atomic Energy Research Institute

2 Outline 1. Introduction 2. Status of SFR Cladding Tube Development Advanced cladding materials development Cladding tube fabrication Evaluation of cladding tube 3. Future Works 4. Summary 2

3 FM Steels for SFR Cladding Tubes Ferritic/martensitic steels High thermal conductivities Low expansion coefficients Excellent irradiation resistance to a void swelling Handling Socket Duct Fuel Pin Upper End Plug Wire Wrap Upper Gas Plenum Cladding materials Development of FM steels Basic composition 9Cr-2W steel Nose Piece Coolant Port Fuel Slug Lower End Plug and Shielding 3

4 Core Environment & Design Requirements Core Environment Inlet temperature : 390 o C Outlet temperature : 545 o C Fuel temperature : > 650 o C Fast neutron fluence : > 200 dpa Hoop stress (end of life) : 70MPa 3-4 cycles (1 cycle : 18 month) : 50,000 hrs Design Requirements of Cladding Tube Thermal strain : < 1% Total strain : < 3% Swelling : < 5% 4

5 Target of SFR Cladding Tubes Development of new cladding having higher creep rupture strength Development of cladding tube fabrication process Max. allowable temp. of cladding tube Max. fluence of cladding tube KALIMER 600 New Target 630 o C Above 650 o C 200 dpa > 200 dpa 5

6 Strengthening mechanism of FM steels Solid Solution Strengthening Precipitation Strengthening W, Mo, V, Nb, Ta, B, C, N, Group I II III IV V VI VII VIII Period hydrogen 1) Cr 5) B helium 1 1 2) Mo, W, Re 6) Si, Mn 2 H 3) V, Nb, Ta, Ti 7) Ni, Cu, Co He 5) C, N 8) Al, P, S lithium beryllium boron carbon nitrogen oxygen fluorine neon Li Be B C N O F Ne sodium magnesium aluminium silicon phosphorus sulfur chlorine argon Na Mg Al Si P S Cl Ar potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe [ ] caesium barium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury thallium lead bismuth polonium astatine radon * Cs Ba Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn [ ] [ ] [ ] francium radium rutherfordiu m dubnium seaborgium bohrium hassium meitnerium darmstadtiu m roentgenium ununbium ununtrium ununquadiu m ununpentium ununhexium ununseptium ununoctium ** Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Uub Uut Uuq Uup Uuh Uus Uuo [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [277] [284] [289] [288] [292] [291]*** [294]*** 6

7 Alloy Design Batch 0 Batch 1 Batch 2 B001 (1 alloy) : Ref. alloy 1. B001( 1종 ): 기준합금 9Cr-2W00 2. B002, B002~B003(3 3 (2 alloys) 종 ):B 첨가 : B 영향 9Cr-2WB1 9Cr-2WB2 3. B004~5 B004~B005(2 alloys) 종 ):C 최적화 : C 9Cr-2WC1 9Cr-2WC2 4. B006~8 B006~B008(3 alloys) 종 ):V/Nb : V, 최적화 Nb 9Cr-2WVNb1 9Cr-2WVNb2 9Cr-2WVNb3 5. B009~B010(2 B009~10 alloys) 종 ):Ta 첨가 : Ta 영향 9Cr-2WVNbTa1 9Cr-2WVNbTa2 B101 (1 alloy) : Ref. alloy 1. B101(1종 ): 기준합금 9Cr-2WVNbTaB1 2. B102~B104(4종 ):V, Nb, Ta 함량 2. B102~4 (4 alloys) : V, Nb, Ta 최적화 9Cr-2WVNbTaB2 9Cr-2WVNbTaB3 9Cr-2WVNbTaB4 3. B105 (1종(1 ):C, alloy) N 최적화 : C, N 9Cr-2WVNbTaB5 4. B106~B110(5 B106~10 종 alloys) ): Ti, Zr, : Pd, Pt, Nd 영향평가Ti, Zr, Pd, Pt, Nd 9Cr-2WVNbTiB 9Cr-2WVNbZrB 9Cr-2WVNbPdB 9Cr-2WVNbPtB 9Cr-2WVNbNdB 1. B201 (1 alloy) : reference alloy 9Cr-0.5Mo2W-VNbTa B202~B203 (2 alloys) : Ta effect 9Cr-0.5Mo2W-VNbTa-N1 9Cr-0.5Mo2W-VNbTa-N2 3. B204~B205 (2 alloys) : V effect 9Cr-0.5Mo2W-VNbTa-V1 9Cr-0.5Mo2W-VNbTa-V2 4. B206~B208 (3 alloys) : W, N, B, V effect 9Cr-0.5Mo3W-VNbTa-00 9Cr-0.5Mo2W-VNbTa-B1 9Cr-0.5Mo2W-VNbTa-VB1 5. B209~B210 (2 alloys) : P effect 9Cr-0.5Mo2W-VNbTa-P1 9Cr-0.5Mo2W-VNbTa-P2 6. B211~B213 (3 alloys) : Zr, Pt, Ge, Cu effect 9Cr-0.5Mo2W-VNbTa-Zr 9Cr-0.5Mo2W-VNbTa-Pt 9Cr-0.5Mo2W-VNbTa-GeCu 7. B214~B215A (3 alloys) : Nb, Ta, N effect 9Cr-0.5Mo2.2W-3VNb 9Cr-0.5Mo2.2W-3VNbTa 9Cr-0.5Mo2.2W-3VNbTaN 7

8 Stress (MPa) Advanced Cladding Materials Development Alloy design and manufacturing 38 alloys in 3 batches Vacuum induction melting (30kg) Hot rolling (thickness : 15mm) Heat treatment (normalizing at 1050 o C, tempering at 750 o C) Performance tests Microstructure examination Sodium compatibility tests Creep/tensile tests CRS of new alloy improved by more than 35 % from HT9 9Cr-2W-0.05Ta-0.08N-0.006B 9Cr-2W-0.05Ta-0.02N-0.15B o C Time to Rupture (hr) HT9 T92 PNC-FMS KAERI 8

9 Fabrication 피복관예비시제품 of HT9 Cladding 제조 Tube Hollow billet VIM (1 ton ingot) Hot forging at 1200 o C Machining (OD 180mm) Mother tube fabrication Hot extrusion (OD 54mm) Pilgering & Drawing Intermediate HT (OD 19mm) Tube fabrication Drawing (4 times) Intermediate heat treatment Final heat treatment Cladding tube (OD 7.4mm, T 0.56mm) 1 ton ingot Drawing Hot extrusion Heat treatment Intermediate tube Cladding tube 9

10 Microstructure of HT9 Cladding tube Dimension - Outer diameter : mm - Inner diameter : mm - Thickness : mm Microstructure Martensite + Delta ferrite Surface roughness - Outside : μm - Inside : μm Straightness < 10 μm 10

11 Tensile Test of Cladding Tubes Ref.) W.L. Bell, et al., GE, Proc. of Topical Conf. on Ferritic Alloys for use in Nucl. Energy Technologies (1983) Ref.) W.L. Bell, et al., GE, Proc. of Topical Conf. on Ferritic Alloys for use in Nucl. Energy Technologies (1983) Test temperature : RT ~ 700 o C Gr.92 tube had higher yield and ultimate tensile strength than HT9 tube. Total elongation of Gr.92 tube was a little lower than that of HT9 tube. HT9 cladding tube had tensile properties similar to the data in the literature. 11

12 Burst Test of Cladding Tubes Test conditions Burst test was performed by pumping gas up to burst. Test results Ultimate hoop stress HT9 : 1135MPa (R.T), 488MPa (658 o C) Gr.92 tube had a lower UHS than HT9 tube at elevated temperature RT 12

13 Hoop stress (MPa) Creep Test of HT9 Cladding Tube Test conditions Test temperature : 650 o C Applied hoop stress : 120MPa to 216MPa Test results Time to rupture of HT9 tube 4hrs (216MPa), 9hrs (194MPa) 36hrs (162MPa), 173hrs (140MPa), 524hrs (120MPa) HT9 cladding tube had creep rupture strength similar to the data HT9 (KAERI) 1) HT9 (KAERI-Round bar) 2) HT9 (EP A2) 3) HT9 (EP A2) 4) HT9 (EP A2) 5) in the literature. Creep test of Gr.92 cladding tube is on-going ) 1038C, 5min 760C, 30min 2) 1050C, 30min 750C, 2hr 3) 1100C, 5min 760C, 30min 4) 1040C, 5min 650C, 2hr 5) 1040C, 5min 704C, 2hr Rupture time (hr) 13

14 Final Heat Treatment 650C UTS (MPa) 650C YS (MPa) Heat treatment conditions Normalizing : 950 ~ 1100 o C x 30min Tempering : 700 ~ 800 o C x 1hr Tensile test results Tensile test : 650 o C Future works C 1000C 1050C 1100C Creep test HT9 (AR) 950C 1000C 1050C 1100C Tempering temp. ( o C) Tempering temp. ( o C) AR HT9 :

15 Core Components Development Plan 연구내용 Item 2단계 ( 실증로 1 st 개념설계 phase ) 차기단계 2 nd phase ( 표준설계 ) 차기단계 3 rd phase ( 표준설계 ) ( 12-16) ( ) ( 12-16) ( ) Cladding tube Cold working process Heat treatment conditions Fabri. cladding tube Design of Irra. test rig Fabr. of rig Out-of-pile test (creep, tensile, impact, fracture toughness) Fast reactor irradiation test PIE (swelling, creep etc.) Wire Wire design Fabri. wire Fabr. of rig Out-of-pile test of wire (tensile, creep, impact etc.) Fast reactor irradiation test and PIE Duct design Fabri. duct Out-of-pile test of duct (tensile, creep, impact etc.) Duct Duct fabri. process Fabr. of rig Fast reactor irradiation test of duct PIE (impact, fracture toughness etc.) Assembly parts Design of assembly parts Assembly parts fabrication process Fabri. Assembly parts Out-of-pile test 15

16 Irradiation Test Plan of Cladding Tube Irradiation test : Oct Specimens HT9M1 : 9Cr-2W-V-Nb-B (cladding) HT9M2 : 9Cr-2W-V-Nb-N (cladding) T91 : Modified 9Cr-1Mo (duct) HT9 (cladding & duct) Irradiation temperature : 390 o C, 545 o C, 650 o C Fluence : 20dpa, 80dpa, 160dpa, 200dpa 16

17 Post Irradiation Test Plan of Cladding Tube PIE items Nondestructive tests Visual inspection Irradiation swelling Irradiation creep (pressurized cladding tube) Destructive tests (4 set) Mechanical test (Tension, Charpy impact, fracture toughness, Compact tension) Microstructure (dislocation, precipitation, void) 17

18 Summary Development of advanced FM steels 9Cr-2W-TaVNbB Fabrication and evaluation of cladding tubes HT9 and Gr.92 cladding tube fabrication Creep, tensile, burst, and microstructure HT9 cladding tube fabricated in Korea showed similar mechanical properties with the data in the literature. Future works Fabrication of cladding tubes with new alloys Performance of out-of-pile test Fast neutron irradiation test 18

19 Thank you for your attention! 19