Protected Plutonium Breeding by Transmutation of Minor Actinides in Fast Breeder Reactor

Abstract

The improvement of proliferation resistance properties of Pu and the burnup characteristics of fast breeder reactor (FBR) had been studied by utilizing minor actinides (MAs) to produce more 238 Pu from 237 Np and 241 Am through neutron capture reaction. The higher the 238 Pu content in the fuel, the higher the proliferation resistance of the fuel would be owing to the natural characteristics of 238 Pu with high decay heat and high neutron production. The present paper deals with the assessment of passive measure against nuclear material proliferation by focusing on improving the inherent proliferation barrier of discharged Pu from an FBR. Results showed that 5% MA doping to the blanket of an FBR gives as high as 17-19% 238 Pu, which could be seen as a significant improvement of the proliferation properties of Pu. Moreover, additional 5% ZrH 2 , togather with 5% MA doping to the blanket, could enhance the 238 Pu fraction much more (22-24%). With an assumption of protected Pu whose 238 Pu isotopic fraction is more than 12%, the present paper revealed that protected Pu could be produced more than the Pu consumed (protected Pu breeding) through incineration in an FBR with doping of a minimum 3% MAs or (2% MAs + 5% ZrH 2) to the blanket.

Basic Analysis on Isotopic Barrier of Material Attractiveness Based on Plutonium Composition of FBR

“…In addition, isotopic plutonium compositions in the blanket regions are analyzed, especially the composition of even-mass isotopes of plutonium (Pu-238, Pu-240, and Pu-242), for investigating the plutonium proliferation resistance parameter as an intrinsic aspect of proliferation, which is based on the protected plutonium proliferation concept. 9,10) Adding some TRU materials in the core as well as in the blanket regions will affect the reactor criticality condition as well as fuel breeding capability; however, the study tries to focus on the material attractiveness based on the plutonium isotope composition. Fuel material behavior and its composition will be discussed and evaluated as a function of reactor operation.…”

“…(3) Increasing Pu-238 and Pu-240 Vector Compositions Pu-238 and Pu-240 compositions as main contributors of even-mass plutonium isotopes are evaluated for comparative analysis. The axial blanket has a relatively harder neutron spectrum, 10) which gives a different plutonium composition compared with that in the radial direction of the blanket region. The obtained results for some isotopic plutonium composition in the axial blanket and radial blanket regions are shown in Fig.…”

“…6,7) In addition, MA can be seen as ''an additional fuel'' to be used for generating power and maintaining criticality of the reactors; it can also be recognized as a potential material for protected plutonium proliferation for a specific reactor type. 4,5,9,10) Reactor core behavior, actinide composition, and plutonium vector composition analyses from the transmutation process of TRU in the core and blanket regions, especially MA, are the main issues in this study.…”

“…While improving fuel cycle technology, recycled MA is also recognized as usable for achieving more protected plutonium production as a nuclear nonproliferation concern. 9,10) MA loading is adopted to improve the intrinsic properties of plutonium isotopes such as higher material barrier of even mass number (Pu-238, Pu-240, and Pu-242). In regard to their intense decay heat (DH) and high spontaneous fission neutron (SFN) rate, these parameters were used for improving the proliferation resistance of plutonium.…”

Measurement and Analysis of Reactivity Worth of237Np Sample in Cores of TCA and FCA

“…3) In this proposal, this nuclide plays an important role as a resource for 238 Pu which adds an intrinsic feature of the proliferation resistance to plutonium produced in irradiated uranium, through the decay heat and spontaneous fission neutrons. The large capture cross section of 237 Np introduces the property of being a burnable poison to this nuclide when it is used in the light water reactor fuel.…”