Environmentally friendly application of hydrides to nuclear reactor cores

Abstract

As new environmentally friendly techniques, hydride materials have been proposed to be introduced to fast reactor (FR) cores in this paper. Hydrogen atoms in metal hydride can efficiently moderate fast neutrons. Based on this fact, some metal hydrides have been investigated for their potential environmentally friendly application as nuclear materials to be used in FR cores. Two types of utilisation of metal hydrides in FR cores are discussed in this paper. One is the application of hafnium hydride as neutron absorber in FR cores. The core design has been carried out to examine its characteristics as well as to evaluate the cost reduction effect. Demonstration of the fabrication of hydride pins has been performed using hydride pellets and stainless steel claddings. The coating technique of the inner cladding surface has also been developed to reduce the permeation of hydrogen through the stainless steel cladding. The physical and chemical properties of the pellet have been measured for the purpose of designing a hafnium hydride pin. Irradiation test of the hydride pins has been performed in the experimental FR, JOYO, Japan Atomic Energy Agency. The other application is the utilisation as a transmutation target of long lived nuclear wastes. Hydride fuel containing 237 Np, 241 Am and 243 Am has been studied for a candidate transmutation target to be used to reduce the radioactivity of long lived nuclides contained in the nuclear wastes, which are obtained after reprocessing spent fuels.

Metal hydrides in engineering systems, processes, and devices: A review of non-storage applications

“…Boron carbide (B 4 C) is typically used as a neutron absorber, which generates helium gas and has a short life. Recently (2012) Konashi et al [117] envisioned a new material that would increase transmutation rate without generating helium gas for environmentally benign nuclear applications. In the latter study, hydrides were proposed and investigated for application in nuclear reactor cores.…”

Depleted Uranium as Hydrogen Storage Material

“…Yamawaki, the top author of this paper, and his co-workers previously proposed a surplus electricity storage system utilizing depleted uranium as a base storage material [1,2] . Hydrogen absorption-desorption properties of various uranium alloys such as with Zr, Ti, Mn, Fe or Ni have been studied to find the alloys with improved anti-powdering capacity as well as with high desorption pressure by Yamawaki and his co-workers [2][3][4][5][6][7][8][9] . As for UCo intermetallic compound, its hydriding properties were studied by Andreev et al in addition toYamamoto et al [8,10] .…”

Nuclear Forward Scattering of Synchrotron Radiation byRu99

“…[15] and studies of partial amorphization of Er 2 O 3 under applied pressure [16]. Moreover, a study of a yet unexplored chemistry related to the novel electronic properties of hafnium compounds such as two dimensional hafnium honeycombs -similar to graphene -structure [17], hafnium carbides for use in extreme environments [18], and studies related to the applications of hafnium hydride in nuclear power plants [19] are now feasible by nuclear forward scattering on 176 Hf (88.349(24) keV).…”