[en] Five levels of increasing effectiveness are identified in conditioning weapons grade plutonium (WPu) to make it unattractive or unavailable for weapons use. These are: dismantling of weapons delivery systems; dismantling of warheads; converting the metallic WPU to oxides; impeding access to the Pu either by immobilisation and disposal in a high level radioactive waste repository or by burial in a deep borehole; deteriorating the isotopic composition of the Pu. Conversion to MOX fuel seems the most reasonable disposition alternative both for surplus civil grade plutonium (CPu) and the WPU being made available by disarmament, which at 140t represents only 9-12% of the total Pu inventory to be dealt with in the 30-40 years required to eliminate it. In Russia the MOX fuel route only is being considered. MINATOM favours the use of fast neutron reactors but there is pressure from the European Union to consider VVERs as well and suggestions from Canada that some of its CANDU reactors might be used. In the USA, deep boreholes, immobilisation and reactors are still being studied as options. The isotopic composition of WPu, its radioactivity and the fact that the raw material contains 1-2% Ga, will have to be taken into account in the fabrication and design of MOX fuel. Fabrication using CPu is well established in Europe but Russia has rejected the use of any of these facilities for its WPu. Within the reactors option the USA is still considering fabrication in Europe, but problems surround the contamination of the plants with Ga and transatlantic shipment of Pu and MOX. (UK)

No abstract available

[en] In his presentation on nuclear fuel activities in belgium the author considers the following directions of this work: fuel fabrication, NPP operation, fuel performance, research and development programmes

No abstract available

No abstract available

[en] In a topical paper presented at the Technical Meeting on ‘Fissile Material Management Strategies for Sustainable Nuclear Energy’, Vienna, 12-15 September 2005, sensitivity of fuel costs to the quality of reprocessed uranium (RepU) was illustrated for centrifuge-enriched RepU. The economics of RepU was treated very superficially, since the purpose was only to indicate how much the value of RepU depends on the burnup of the spent fuel from which the RepU was recovered. Furthermore, the prices in the front end of the fuel cycle (U₃O₈, conversion, enrichment and fuel fabrication) were taken at the market levels of 2004-2005. Since then, the price of natural uranium (Unat) has increased by a factor 9 and the enrichment price by a factor 1.7, and some believe that those prices might continue to escalate further beyond the normal inflation rate of goods. In this context, this paper analyses in more detail the cost of enriched reprocessed uranium (ERU) fuel, as a function of the RepU quality, market prices of the fuel cycle front end and enrichment technology. No attempt is made to be exhaustive. It is only a case study based on extreme price assumptions. The results are one input to a decision on whether to utilize available RepU in the short term to benefit from attractive enrichment conditions or to store it as strategic reserve to be used later. Besides economic evaluations, other factors are also to be taken into consideration: perspectives of future burnup increases, evolution of the regulatory limitations, political decision to phase-out nuclear energy, etc. (author)

[en] Extending burnup affects the characteristics of spent fuel to a larger extent than simple linear extrapolation. Increased alpha (and consequent decay heat generation) and neutron activities are the predominant features impacting on spent fuel management, both in the open and closed cycle options. Reprocessed U has properties only marginally affected by the higher burnup. To the contrary, the properties of Pu are strongly modified and higher Pu contents are required. However, the time scale for the MOX fuel industry to cope with this challenging future is stretched over a long enough period for the MOX manufacturing plants to be adapted in due time and for the adequate data base to be implemented. (author). 10 refs, 13 figs

[en] The technology of fabricating plutonium-bearing coated particle fuel for HTR's has advanced sufficiently to make an assessment of plutonium coated particle fuel production. The design of a suitable kernel and coating for power reactor fuel is elaborated and the fabrication route specified in order to estimate production costs. It is concluded that for an initial 3,000 MW(e) HTR programme based on the feed and breed fuel cycle with plutonium/thorium, the plutonium feed coated particle fabrication costs will be about L210-220/kg fissile isotopes. This is within 5% of the fabrication cost for U-235 feed fuel estimated using the same costing convention. (author)

[en] This paper proposes a type of target rod based on the use of coated particles, for an efficient incineration of americium in nuclear reactors. The analysis takes advantage of the experience gained in the past from long duration irradiation without damage of coated particles with plutonium oxide kernels. A conservative theoretical evaluation of the gas pressure inside the coated particles at the end of irradiation allows comparing the well known conditions of the plutonium oxide particles which were successfully irradiated to high burn-up, with a preliminary design of americium oxide particles. (authors)

[en] The development of Pu fuelled coated particles based on a kernel consisting of PuO₂/PuO₃ dispersed in a carbon matrix bonded with furfuryl alcohol polymer and surrounded by a complex coating of pyrocarbon and silicon carbide is described. Details are given of the manufacture of fuels coated at ∼1500°C for irradiation tests in the Studsvik and Dragon Reactors. Also described is the preparation of a fuel where specification was dictated by the requirements of a feed fuel for a feed/breed HTR. In this case the fuel kernels of composition PuO_x/20C and of ∼500 μm diameter were coated with a triplex PyC/SiC/PyC coat of 160-170 μm, the outer PyC layer being laid down at 2000°C. Evidence is presented which suggests that if a sufficiently high partial pressure of carbon monoxide is maintained over the PuO₂/C fuel kernels during their heat treatment and during the early stages of coating with the initial pyrocarbon layers, this type of fuel can be prepared without incurring significant losses of plutonium. (author)