Plutonium Fuel Development Facility Experimental Evaluation of Am and Np Bearing Mixed Oxide Fuel Properties M. Kato, K. Morimoto, A. Komeno, S. Nakamichi, M. Kashimura Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency Japan Atomic Energy Agency
Plutonium Fuel Development Facility Background － Development of MOX containing MA － � Japan Atomic Energy Agency has developed homogeneous mixed oxide containing minor actinides (MA-MOX) as a fuel of the Hollow pellets of MOX advanced fast reactor. Specification of the fuel pellet Type : Hollow type Pu content : 20 - 30% MA content : - 5%(Np+Am+Cm) Density : 93%TD O/M ： 1.95 Burn-up : 150GWd/t Pellets of (Np 0.02 Am 0.02 Pu 0.3 U 0.64 )O 2 � Physical property measurements of Am and Np bearing MOX � The effect of MA addition on the physical properties
Plutonium Fuel Development Facility Outline � Sample preparation � Phase state and Phase separation � Lattice parameters � Oxygen potentials � Melting temperatures � Thermal conductivities
Plutonium Fuel Development Facility Sample preparation UO 2 , (U,Pu)O 2 , (U,PuNp)O 2 , (Pu,Am)O 2 Starting materials Ball mill Press at 1923-1973K for 3-4 h in 5%H 2 /Ar flowing Sintering gas added moisture Annealing for MO 2.00 at 1123K for 4 h in the atmosphere of Δ G=-400-420kJ/mol Annealing to adjust O/M ratio at 1123-1973K for 3-25 h in an appropriate atmosphere Measurement
Plutonium Fuel Development Facility Sample preparation List of samples Composition Sample Name U(%) Pu(%) Np(%) Am(%) O/M MOX-1 70.3 29 0.7 2.00-1.909 (U 1-z-y’-y“ Pu z Am y’ Np y” )O 2.00-x MOX-2 69.5 30 0.5 2.00-1.924 6%Np-MOX 64.3 29 6 0.7 2.00-1.914 12%Np-MOX 58.3 29 12 0.7 2.00-1.909 Pu : Z = 0 – 97.9% 2.4%Am-MOX 67.6 30 2.4 2.00-1.951 Am : y’ = 0.5 – 7.2% 2%Np/Am-MOX 66 30 2 2 2.00-1.923 1.8%Np/Am-MOX 66.4 Np : y” = 0 – 12% 30 1.8 1.8 2.00-1.919 12%Pu-MOX 87.9 11.8 0.3 2.00-1.971 x : x = 0 – 0.282 20%Pu-MOX-1 79.7 19.9 0.4 2.00-1.942 (O/M=2.00 – 1.718) 20%Pu-MOX-2 78.7 19.8 1.5 2.00-1.947 MOX-3 69.6 29.8 0.6 2.00 40%Pu-MOX-1 59.6 39.7 0.7 2.00-1.916 40%Pu-MOX-2 58.5 39.6 1.9 2.00-1.961 40%Pu-MOX-3 58.4 38.3 3.3 2.00 43%Pu-MOX 53.7 42.8 3.5 2.00 46% Pu-MOX 51.4 46.3 2.4 2.00-1.718 60% Pu-MOX 37.7 60 2.3 2.00 2%Am-PuO 2 97.9 2.1 2.00 6%Am-PuO 2 93.6 6.4 2.00 7%Am-PuO 2 94 7.2 2.00
Plutonium Fuel Development Facility Homogeneity of samples 1000 700 900 600 800 500 700 600 ty ty 400 ntensi ntensi 500 I 300 I 400 300 200 200 100 100 0 0 110 115 120 125 130 135 140 145 110 115 120 125 130 135 140 145 ２ θ 2θ X-ray diffraction pattern Pu U U Pu SEM SEM Am Np Am EPMA analysis on cross section (U 0.668 Pu 0.3 Am 0.016 Np 0.16 )O 2.00 (U 0.537 Pu 0.428 Am 0.035 )O 2.00
Plutonium Fuel Development Facility Phase State at room temperature 2.10 1200 Single fcc Phase 1000 800 y 2.00 t i ens 600 Single phase nt I 400 200 600 1.90 0 ２ θ Two fcc Phases 500 O/M Two phases 400 ty 1.80 ensi 300 nt I 200 100 1.70 0 110 115 120 125 130 135 140 145 fcc single phase 2θ Two pahases 1.60 0 20 40 60 80 100 Pu content (%) Phase diagram in U-Pu-O system at R.T. Sari et al.
Plutonium Fuel Development Facility Phase Separation Behavior (a) (b) 800 MOX Phase separation temperature (K ) 6%Np-MOX 700 12%Np-MOX 1.8%Np/Am-MOX 2.4%Am-MOX 600 6%Np-MOX MOX 500 MOX-Np MOX-Np/Am (c) (c (d) MOX-Am 400 ) O/M=1.91-1.93 300 0 5 10 15 20 MA content (%) The effect of MA content on the phase separation temperature. Am/Np-MOX Am-MOX 50μm (a)(Pu 0.3 U 0.7 )O 1.927 � No effect of phase separation (b)(Pu 0.3 Np 0.06 U 0.64 )O 1.92 on the fuel properties. (c) (Pu 0.3 Np 0.016 Am 0.016 U 0.68 )O 1.92 (d) (Pu 0.3 Am 0.024 U 0.636 )O 1.921
Plutonium Fuel Development Facility Lattice parameters 5.47 5.52 Calculation Np-MOX Am-MOX 5.46 Am/Np-MOX 5.50 Experiment Am-MOX Np-MOX Lattice parameter (A) o Am/Np-MOX 29%Pu Lattice parameter (A) 5.45 5.48 Np 12%Pu-MOX 20%Pu-MOX-1 Np/Am 5.44 5.46 20%Pu-MOX-2 Am 6%Np-MOX 12%Np-MOX 40%Pu MOX-1 1.8%Np/Am-MOX 5.44 2%Np/Am-MOX 5.43 40%Pu-MOX 46%Pu-MOX Reference [11] 30%Pu-MOX 5.42 5.42 1.7 1.75 1.8 1.85 1.9 1.95 2 2.05 0 5 10 15 O/M MA Content (%) � The lattice parameters decrease with MA content, and increase with decreasing the O/M. � The derived model represent the experimental data very well.
Plutonium Fuel Development Facility Oxygen potentials Experiments � Horizon type TG-DTA was G ｌ o ｖ e Box 220cc/min Oxygen sensor employed in the measurement. TG-DTA 200cc/min 20cc/min Reference(Al 2 O 3 ) � The oxygen partial pressure Gas Mixer Oxygen sensor FM was controlled by controlling the Sample MFC MFC Instrument adding ratio of P H2 /P H2O and measured water vapor Air Damper with stabilized ZrO 2 oxygen He/5%H He/0.05%H TG-DTA (Rigaku TG812 8120 mo 0 mode del ) He Measurement Temperature : ～ 1400 ℃ sensors. Gas System Thermo Gravimetry 1 ～ 2000ppmH 2 O 2 Horizontal al dif differentia ial l ty type pe ba bala lance 0.01 ～ 5%H 2 2 Acc Accuracy racy o of t the w e weig eight m mea easu surem ement ent : : ± 1 μ g g (O/M : ± 0.00015 ) � The change of TG attained to Schematic diagram of measurement system equilibrium condition for about 10 -10 0.47 15min. at 1573K TG 15 min � The O/M ratio was calculated 10 -11 0.46 from the weight change. P O2 (atm) TG(mg) 10 -12 0.45 � The O/M ratio and P O2 were P O2 measured with good repeatability 10 -13 0.44 and precision. 10 -14 0.43 500 1000 1500 2000 2500 3000 Time(s) Measurement results
Plutonium Fuel Development Facility Oxygen potentials Measurement Results -250 0 AmO 1.995 1623K (U,Pu,Np,Am)O 2-X 1573K (Thiriet and Konings) 1473K O/M=1.995 -300 (U 0.7 Pu 0.3 )O 2-X [12] 1623K 1573K -200 (U 0.66 Pu 0.3 Am 0.02 Np 0.02 )O 1.995 1473K (U 0.656 Pu 0.32 Am 0.024 )O 1.995 H I 40%Pu (U 0.65 Pu 0.3 Am 0.045 )O 1.995 2 (kJ/mol) -350 J Δ G O2 (kJ/mol) 30%Pu (Osaka et al.) -400 20%Pu Δ G o 10%Pu -400 (U 0.7 Pu 0.3 )O 1.995 (U 0.8 Pu 0.2 )O 1.995 NpO 1.995 -600 (Bartscher and Sari) -450 Besmann et al. (U 0.9 Pu 0.1 )O 1.995 (U 0.6 Pu 0.4 )O 1.995 -500 -800 1.96 1.97 1.98 1.99 2.00 2.01 1000 1200 1400 1600 1800 2000 O/M Temperature (K) The change of the Δ G O2 Comparison of the Δ G O2 of MO 1.995 � The Δ G O2 of (U,Pu,Am,Np)O 2-X are slightly higher than those of MOX without MA. � The slightly higher Δ G O2 is caused by Am content.
Plutonium Fuel Development Facility Melting temperatures Experiments 3000 Liquidus 2900 Two-color pyrometer for control Solidus Temperature (°C) 2800 W capsule Induction heating furnace 2700 Thermal arrest 2600 2500 0 100 200 300 400 500 Elapsed time Heating temperature curve of MOX 3400 Ta 3200 Melting point (K) 3000 Re inner Mo Sample Specimen 2800 Nb 2600 Two-color pyrometer for 2400 Al 2 O measurement 3 2200 2200 2400 2600 2800 3000 3200 3400 Melting point measuered in this work (K) Temperature calibration by standard samples
Plutonium Fuel Development Facility Melting Temperatures Solidus Temperatures depending on Pu content � The data measured by conventional method were in good agreement with other data, and the measured value fell off at about 30%Pu –MOX. 3200 � The reaction between MOX and W was observed in the measured samples with 30% and 40%Pu 3100 content. Temperature (K) 3000 2900 This work W capsule Solidus Re inner Re Latta and Fryxell [7] Solidus Aitken and Evans [8] Solidus Solidus Lyon and Baily [6] 2800 0 10 20 30 40 50 mol% PuO 2
Plutonium Fuel Development Facility Melting Temperatures Solidus Temperatures depending on Pu content � The data measured by conventional method were in good agreement with other data, and the measured value fell off at about 30%Pu –MOX. 3200 � The reaction between MOX and W was observed in the measured samples with 30% and 40%Pu 3100 content. Temperature (K) � The solidus measured with Re- capsule are consistent with that of 3000 MOX with Pu content of less than 20%. 2900 This work W capsule Solidus � It can be concluded that the Re inner Re Latta and Fryxell [7] Solidus solidus temperature measured by Aitken and Evans [8] Solidus using Re inner is true melting Solidus Lyon and Baily [6] 2800 temperature of MOX 0 10 20 30 40 50 mol% PuO 2
Plutonium Fuel Development Facility Melting Temperatures UO 2 - PuO 2 system and effect of MA addition 3150 (b) (a) Calculated by Eqs.(1)-(7) D Np Re inner capsule Am W capsule Np/Am =1 3100 Np Experiment Am Am-MOX Np/Am 38-42%Pu Temperature (K) Liquid Liquid 3050 3000 Solid -4K/1%Am Solid 2950 40%Pu Am content : 0-3.3% 2900 0 10 20 30 40 0 50 2 4 6 Pu content (%) MA content (%) UO 2 -PuO 2 system
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