Concepts for an inert matrix fuel, an overview

Degueldre, C.; Paratte, J.M.

doi:10.1016/s0022-3115(99)00060-4

Cited by 153 publications

(89 citation statements)

References 13 publications

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“…The total lineal length of the grid of the analyzed images was calculated to be 1.107 m and the number of points formed by the intersections of the vertical and horizontal lines was 2400. The volume fraction V V of the MgO and Nd 2 Zr 2 O 7 heterogeneities was determined by counting the number of points formed by the intersections of the vertical and horizontal lines that lay on the phase heterogeneities for each phase and dividing it by the total number of points according to the equation V V  P P P (1) where P P is the number of points that fell on the phase of interest and P is the total number of points. The number of heterogeneity interceptions per unit length N L was also calculated according to N L  N i L (2) where N i is the total number of heterogeneities intercepted of the phase of interest and L is the total lineal length of the grid.…”

Section: Quantitative Stereologymentioning

confidence: 99%

“…1,2 Magnesium oxide (MgO) is a promising candidate for inert matrix (IM) materials due to its high melting point (2827 °C) 2 , high thermal conductivity (13 W/K·m at 1000 °C) 2 , good neutronic properties, and irradiation stability 3,4 However, MgO reacts with water and hydrates easily, which prevents it from being used in light water reactors (LWRs) as an IM. To improve the hydration resistance of MgO-based inert matrix materials, Medvedev 5 and coworkers have recently investigated the introduction of a secondary phase that acts as a hydration barrier.…”

Section: Introductionmentioning

confidence: 99%

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Neri Final Technical Report, De-Fc07-O5id14647, Optimization of Oxide Compounds for Advanced Inert Matrix Materials

Nino¹

2009

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The following is a technical report summarizing all the procedures, experiments, simulations and technical findings of this NERI project. For additional information, details or technical questions regarding this project, please contact jnino@mse.ufl.edu MgO and NDZ......................................................................69 8.4. Grain Size Dependence of MgO and NDZ Polycrystal Thermal Conductivity75 8.5 2009 Composite Processing and Characterization IntroductionIn order to reduce the current excesses of plutonium (both weapon grade and reactor grade) and other transuranium elements, a concept of inert matrix fuel (IMF) has been proposed for an uranium free transmutation of fissile actinides which excludes continuous uranium-plutonium conversion in thermal reactors and advanced systems. 1,2 Magnesium oxide (MgO) is a promising candidate for inert matrix (IM) materials due to its high melting point (2827 °C) 2 , high thermal conductivity (13 W/K·m at 1000 °C) 2 , good neutronic properties, and irradiation stability 3,4 However, MgO reacts with water and hydrates easily, which prevents it from being used in light water reactors (LWRs) as an IM. To improve the hydration resistance of MgO-based inert matrix materials, Medvedev 5 and coworkers have recently investigated the introduction of a secondary phase that acts as a hydration barrier. An MgO-ZrO 2 composite was specifically studied and the results showed that the composite exhibited improved hydration resistance than pure MgO. However, ZrO 2 is insoluble in most acids except HF, which is undesirable for fuel reprocessing. Moreover, the thermal conductivity of ZrO 2 is low and typically less than 3 W·m at 1000 °C. 6 In search for an alternative composite strategy, Nd 2 Zr 2 O 7 , an oxide compound with pyrochlore structure, has been proposed recently as a corrosion resistant phase, and MgO-Nd 2 Zr 2 O 7 composites have been investigated as potential IM materials. at 1000 °C for the MgO-Nd 2 Zr 2 O 7 composite with 90 vol% MgO was recently calculated and reported. 8,9 Other simulations proposed that the MgO-pyrochlore composites could exhibit higher radiation stability than previously reported. 10 Final optimization of the composite microstructure was performed on the 70 vol% MgONd 2 Zr 2 O 7 composite that burnup calculations had shown to have the closest profile to that of MOX fuel. Theoretical calculations also indicated that a homogeneous 70 vol% MgO composite could achieve the desired microstructure that would result in satisfying the dual requirements of good thermal properties. Experimental Procedures Composite Synthesis Solid State Synthesis of Nd 2 Zr 2 O 7Stoichiometric ratios of Nd 2 O 3 (Alfa Aesar 99.9%) and ZrO 2 (99.7%) were added to spherical 3 mm and 10 mm yttria stabilized zirconia (YSZ) milling media in a PTFE (polytetrafluoroethylene) ball mill jar with 100 ml of deionized water and 3 ml of ammonium polyacrylate dispersant (20 vol% Darvan 821A in deionized water). The slurry was milled for 24 hours on the ball mill at 85 rpm ...

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Section: Quantitative Stereologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Neri Final Technical Report, De-Fc07-O5id14647, Optimization of Oxide Compounds for Advanced Inert Matrix Materials

Nino¹

2009

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“…Application of the annular fuel concept is particularly attractive for such task because much higher power density is achievable with such fuel geometry resulting in faster rate of Pu destruction. The use of fertile free fuel matrix for hosting the Pu to be burnt offers additional advantage because it averts generation of additional Pu in contrast to conventional mixed oxide (MOX) fuel approach [Degueldre and Paratte, 1999, Lombardi and Mazzola, 1996, Chodak et al 1997]. …”

Section: Evaluation Of Plutonium Burning In Fertile-free Annular Fuelmentioning

confidence: 99%

“…The potential fertile free fuel core design challenges are well known and reported in numerous publications [Degueldre and Paratte, 1999, Kloosterman and Damen, 1999, Kasemeyer et al 1998]. Displacement of U238 with fertile free matrix results in less negative Doppler coefficient of the fuel, which is particularly important for mitigation of reactivity initiated accident consequences.…”

Section: Evaluation Of Plutonium Burning In Fertile-free Annular Fuelmentioning

confidence: 99%

High Performance Fuel Desing for Next Generation Pressurized Water Reactors

Kazimi¹,

Hejzlar²

2006

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“…Silicon carbide is also well known for its chemical inertness, good thermal conductivity and excellent mechanical properties, all of which are requirements for a qualified IMF candidate [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Separation of Nuclear Fuel Surrogates from Silicon Carbide Inert Matrix

Baney¹

2008

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Project End Date: September 12, 2008 (with a six mo. no cost extension) Research ObjectivesThe objective of this project has been to identify a process for separating transuranic species from silicon carbide (SiC). Silicon carbide has become one of the prime candidates for the matrix in inert matrix fuels ,(IMF) being designed to reduce plutonium inventories and the long halflives actinides through transmutation Since complete reaction is not practical it become necessary to separate the non-transmuted materials from the silicon carbide matrix for ultimate reprocessing. This work reports a method for that required process.An efficient process has been developed for separating transuranic species from a silicon carbide (SiC) matrix. At high temperature (above 850 ºC) SiC can be oxidized in molten alkali salt such as sodium carbonate (Na 2 CO 3 ) and potassium carbonate (K 2 CO 3 ) and form water soluble products such as sodium or potassium silicate. SiC fine powder (1micron) was totally dissolved in Na 2 CO 3 molten salt after 30 min heat treatment at 900 ºC. SiC pellets were completely dissolved in K 2 CO 3 molten salt after approximate 40 hours heat treatment at 1050 ºC. Separation was achieved by dissolving the products obtained from SiC corrosion in water. Ceria (CeO 2 ) remained unchanged and was not corroded in these molten salt environments.

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Concepts for an inert matrix fuel, an overview

Cited by 153 publications

References 13 publications

Neri Final Technical Report, De-Fc07-O5id14647, Optimization of Oxide Compounds for Advanced Inert Matrix Materials

Neri Final Technical Report, De-Fc07-O5id14647, Optimization of Oxide Compounds for Advanced Inert Matrix Materials

High Performance Fuel Desing for Next Generation Pressurized Water Reactors

Separation of Nuclear Fuel Surrogates from Silicon Carbide Inert Matrix

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