nitride fuel and pyrochemical process developments for transmutation of minor actinides in jaeri

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Nitride Fuel and Pyrochemical Process Nitride Fuel and Pyrochemical Process Developments for Developments for Transmutation of Minor Actinides Transmutation of Minor Actinides in JAERI in JAERI Masahide Takano, Mitsuo Akabori, Kazuo Minato, Yasuo Arai Japan Atomic Energy Research Institute 8 th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2

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Nitride Fuel and Pyrochemical Process Developments for Transmutation of Minor Actinides in JAERI. Masahide Takano, Mitsuo Akabori, Kazuo Minato, Yasuo Arai Japan Atomic Energy Research Institute. - PowerPoint PPT Presentation

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Page 1: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

Nitride Fuel and Pyrochemical Process Nitride Fuel and Pyrochemical Process Developments for Developments for

Transmutation of Minor ActinidesTransmutation of Minor Actinidesin JAERIin JAERI

Masahide Takano, Mitsuo Akabori, Kazuo Minato, Yasuo AraiJapan Atomic Energy Research Institute

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Page 2: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

>Background>PROMINENT program>Fabrication of MA nitrides Carbothermic synthesis of (Pu,Am,Cm)N & (Pu,Am,Cm,Zr)N

>Property Measurements of MA nitrides Hydrolysis & Evaporation behavior of AmN & (Am,Zr)N

>Pyrochemical process Pu nitridation in Pu-Cd alloy

>Irradiation test (Pu,Zr)N & PuN+TiN

>Conclusion

Content

Page 3: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Nitride fuel cycle - background

> JAERI has proposed double strata fuel cycle for MA transmutation, based on U-free nitride fuel, ADS, and pyrochemical reprocessing.

> Expected on nitride fuel: Good thermal properties, Mutual solubility among MA nitrides, High heavy metal density

> Experiments on MA nitride: Limitation in facility, apparatus, handling, material amount, High purity inert atmosphere required

> We have studied on: Fuel fabrication technology Property measurements Irradiation behavior Pyrochemical process

Page 4: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

PROMINENT program

Pyrochemical ProcessTechnology

Fuel IrradiationExperiment

Nitride Fuel Cycle

Fuel Fabrication

Reprocessing Pu/MA burning

Fuel FabricationTechnology

Fuel PropertyMeasurement

Research areas in PROMINENT program

> JAERI, Osaka Univ, MMC, NDC, JAPC

> Started Nov. 2002, five year program

> Development and demonstration of elemental technology for nitride fuel cycle in laboratory scale

PROMINENT:Property Measurements, Pyrochemical Process and Irradiation Experiments Neededfor Nitride Fuel Cycle Technology.

Page 5: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Fabrication of MA nitrides (1)

243Am2O3, (240Pu,244Cm)O2, ZrO2

amorphous carbon

> Starting materials

> Fabrication methodCarbothermic reduction of oxides mixture

MOx + xC + 1/2N2 MN + xCO

Nitridation: N2 1300 ºC

Decarburization: N2+4%H2 1500 ºC> Analyses

X-ray diffractionN,O,C analyses

(Pu,Am,Cm)N

(Pu,Am,Cm,Zr)N

Process temperature and CO gas release

> Pu+Am+Cm+(Zr) nitrides

30~40 mg scale

Page 6: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Fabrication of MA nitrides (2)

Expected product

Pu/Am/Cm/Zr molar ratio

C/O molar ratio

Mixture weight (mg)

(Pu,Am,Cm)N (Pu,Am,Cm,Zr)N

31.40 37.58

0.45 /0.34 /0.21 /0 0.14 /0.10 /0.06 /0.70

1.32.0

Composition of the oxides and carbon mixtures

Page 7: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Fabrication of MA nitrides (3)

(Pu,Am,Cm)N

(Pu,Am,Cm,Zr)N

XRD profiles of products

> (Pu,Am,Cm)N Single phase solid solution 0.4956nm (0.4960 nm by Vegard’s law) No oxide phase Low carbon content (<0.05 wt%)

> (Pu,Am,Cm,Zr)N Double phases with NaCl structure different (Pu,Am,Cm)/Zr ratio Low oxygen content (0.15 wt%) High carbon content (1.3 wt%) remained as carbonitride

Page 8: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

AmN Am(OH)3 Am2O3

Property measurements (1) Hydrolytic behavior

> MA nitrides are reactive with moisture

> Hydrolysis of AmN and (Am,Zr)N observed in ambient air

> AmN reacted with moisture to form Am(OH)3

> (Am0.1Zr0.9)N retained the phase

over 1000h

Weight gain of AmN, (Am,Zr)Nand (Dy,Zr)N in air and moist N2

Page 9: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Property measurements (2) Evaporation behavior> Am has high vapor pressure

> Evaporation behavior of AmN & (Am,Zr)N in He gas flow

AmN = Am(g) + 1/2N2

> Evaporation rate constant, k (s-1) v = -(dN/dt) = kN

> AmN retained the phase while heating, no metallic phase

> Selective evaporation of AmN on (Am,Zr)N change in composition

> k of AmN in (Am,Zr)N depressedArrhenius’ plots of k

Page 10: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Property measurements (3) New apparatus

> Apparatus for thermal property measurements installed

> Thermal diffusivity ~ laser flash method sample diameter 3~5 mm installed in Ar atmosphere

> Specific heat capacity ~ drop calorimeter sample sealed in Pt capsule

> Designed for nitrides and small sized samples

> Thermal expansion ~ high temp. XRD installed in Ar atmosphere

Page 11: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Pyrochemical process of nitride fuel

> Anodic dissolution of PuN in LiCl-KCl eutectic salt examined

> Recovery of Pu into liquid Cd cathode demonstrated with high current efficiency

Schematic diagram of pyrochemicalprocess for nitride fuel

> Pu in Pu-Cd alloy converted to PuN

> Experiments on Am-containing nitride will start soon at “TRU-HITEC”

Page 12: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Nitridation of Pu in Pu-Cd alloy

(a) N2 bubbling process

Cd

N2 gas

Pu-Cd

PuN

Furnace

(b) Nitridation-distillation combined process

> N2 bubbling process

U in U-Cd: 100% recovery

Pu in Pu-Cd: only 10% recovery

decrease in Pu activity in Pu-Cd

> Nitridation-distillation combined process

Pu: 99% recovery

PuN with high purity obtained

Pu-Cd (12wt% Pu) Recovered PuN

CrucibleN2 gas

Pu-Cd melt

PuN

LiCl-KCl

723K

973K

Page 13: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Irradiation test ongoing

(Pu,Zr)N

PuN+TiN

> (Pu,Zr)N & PuN+TiN pellets Pu: 20wt%, He-bond

> Irradiation ongoing at JMTR

Linear power: ~40kW/mTarget burnup: 20 at% of Pu

> Basic irradiation behavior of U-free nitride fuel

Irradiation: May 2002 ~ Nov. 2004PIE: Apr. 2005 ~

Irradiation test schedule> Irradiation of (Pu,Np,Zr)N pellet scheduled at JOYO with JNC

Page 14: Nitride Fuel and Pyrochemical Process  Developments for  Transmutation of Minor Actinides in JAERI

OECD/NEA 8th Information Exchange Meeting on Actinide and Fission Product Partitioning & Transmutation, Las Vegas, USA, 9-11 Nov. 2004

Concluding remarks

> (Pu,Am,Cm)N and (Pu,Am,Cm,Zr)N synthesized by carbothermic reduction of the oxides

Mutual solubility among PuN-AmN-CmN was demonstrated.

> Hydrolysis and evaporation behavior of AmN and (Am,Zr)N studied

> Pu nitridation in Pu-Cd alloy investigated

AmN was chemically and thermodynamically stabilized by formation of solid solution with ZrN.

Simultaneous nitridation-distillation process yielded high purity PuN.