Year
2005
Abstract
Proliferation resistance is considered as the most problematic issue in promoting nuclear power in developing countries. Creation of intrinsic proliferation resistance (IPR) features would help in making more friendly environment for nuclear power generation. The key point in creating the IPR is the choice for the fuel form that would make all the efforts of extracting the fissionable nuclides and their use for manufacturing of nuclear explosives particularly unattractive. Three main issues form the base line of the present paper: • Initial fuel composition is to correspond to IAEA safeguard criteria; • Spent fuel is to be characterized by highly denaturated Plutonium isotopic vector; • The choice for fuel matrix form is governed by (a) easy transport of fresh fuel to the power producing site; (b) easy transport and storage of irradiated fuel; (c) easy detectability of fuel loss; (d) complicated technology of heavy metal extraction from fuel matrix. In accordance with IAEA regulations, uranium with 20% 235U content is to be considered as of no direct use [1]. As for the safeguard exemption the only plutonium with 80% fraction of 238Pu is identified by IAEA [1]. The reality of nuclear power production is of course far from reaching the last number. Nevertheless the higher 238Pu content is well understood to be the point for comparison of protected plutonium options [2]. High alpha decay rate of 238Pu requires careful choice of fuel matrix. Traditional (UPu)O2 does not suit well to high 238Pu content in view of swelling problem. The present paper focuses the irradiation performance of coated particle fuels of the HTGR type. It could withstand high alpha swelling and incorporate highly dispersed heavy metal content in the form of microspheres. Thee fuel option were investigated: • UO2 (up to 20% enriched with 235U); • PuO2 (initial plutonium composition corresponds to one from spent uranium PWR fuel with burnup 40 GWd/tHM); • Mix of UO2 (up to 20% enriched with 235U) with Minor Actinides (Np, Am, Cm). The first two were selected just for reference. The last one makes the essence of the present study giving the quantitative assessment of proliferation resistance barrier in terms of • Fraction of even Pu isotopes (238,240Pu); • Decay heat and neutron emission from bare crit of Pu, MA compositions and their mix. The domain of safe irradiation performance (reactivity coefficients) were estimated as a function of fuel burnup and its load (g/sphere).