05 Nuclear fuels (economics, policy, supplies, forecasts)

A molecular kinetic theory has been developed for the acoustic bubble implosion that induces D-D fusion by irradiating the pulsed neutron beam, which was discovered recently by the Oak Ridge National Laboratory Group with deuterated acetone (C3D60). They analysed the bubble behaviour using a modified Raleigh equation, and the implosion using the phasic conservation equation and the interactive shock waves, which are phenomenological and complicated. The molecular kinetics is complementary to the hydrodynamics and can verify cooperatively the phenomenon. Although the exact treatment by the statistical mechanics for the molecular system is intricate, the preliminary theory can estimate the important elements such as the temperature rise of the imploded core with the use of molecular interaction with acoustic wave and pulsed neutron beam, molecular binding potential, surface tension, etc.

03/00627 Plasma heating and current drive systems for the fusion ignition research experiment (FIRE) Swain, D. W. and Carter, M. D. Fusion Engineering and Design, 2002, 63 64. 541-545. FIRE is a high-field, burning-plasma tokamak that is being studied as a possible option for future fusion research. Preliminary parameters for this mach;ne are Ro=2.14 m, a=0.595 m, Bo= 10 T, anh 1,=7.7 MA. Magnetic field coils are to be made of copper and pre-cooled with LN1 bel’;re each shot. The flat-top pulse lkngth desired is 220 s. 106 cyclotron (IC) and lower hybrid rf systems will be used for heating and current drive. Present specifications call for 20 MW of IC heating power, with an additional 10 MW of IC power or 20 MW of lower hybrid power as upgrade options.

03/00628 Radiation resistance of reactor graphites based on inexpensive raw materials Virgil’ev, Yu. S. and Lebedev, I. G. Inorganic Materials ( Translatron qf Neorganiclzeskie Materialy). 2002. 38, (9), 890-894. ExDerimental data are Dresented on the effect of n irradiation on the prhperties of reactor g;aphites based on readily available, inexpensive pitch, schistose, and electrode cokes, instead of the petroleum coke KNPS used earlier. The irradiation-induced sized changes in these graphites are rather small, indicating that they can be used in the production of graphite bushings for nuclear reactors. The experimental data confirm earlier estimates of the irradiation-induced size changes in such graphites.

the open literature at high temperatures. Important future planning guidelines for decontamination and/or chemical cleaning, of steam generator units can be obtained from these results.

03/00632 Thermal-hydraulic analysis for a sodium-heated steam generator using a multi-shell method Sakai, T. et al. Nuclear Engineering and Design. 2003, 219, (I), 35-46. A multi-shell analysis method has been applied to predict the Thermal- hydraulics in a steam generator of a liquid metal reactlor. The method is intended to improve the calculation accuracy for temperature profiles at a wide range of heat exchange rates in a large sized steam generator for the future plant. The calculation accuracy has been examined using experimental 50 MWth steam generator test data that were measured during 1970s and 1980s. The calculation results of temperature profiles were compared with experimental data at 20, 30, SO, 75, 90, and 100% of nominal operating condition. Responses for the stepwise flow rate variations were also evaluated. In conclusion, the calculation accuracy for the temperature profile in the steam generator was improved by using the multi-shell analysis method for a wide range of heat exchange rates.

03/00633 Void reactivity and pin power calculation for a CANDU cell usina the SEU-43 fuel bundle Constantin, M. et ar Annals qf Nuclear Energy. 2003, 30, (3), 301-316. The CANDU type reactors have the ability to accommodate a wide variety of fuel types. For all the used fuel types the void coefficient of the reactivity is positive. In this paper a heterogeneous two-stratified coolant model is used for SEU-43 fuel bundle type. This is slightly enriched uranium (near 1%) with 43 fuel rods dleveloped in INR Pitesti. The coolant is treatkd as a two-phase (liquid and vapour) medium, gravitationally separated. Eigenvalues are computed with the transport code CP_2D at different void fractions and burnup points. For the fresh fuel the MCNP results on the two-startified model a homogeneous model is used to benchmark CP_2D results.

Economics, policy, supplies, forecasts

03/00629 Safety assessment for ITER-FEAT tritium systems Pinna, T. and Rizzello, c’. Fusion Engimwing rrnrl Design, 2002, 63-64. 181 -1X6. The design of the equipment and confinement barriers of ITER-FEAT should be consistent with the basic safety requirement that no emergency plan involving evacuation of the nearby population is required in case of the worst credible accident. Extensive probabilistic and deterministic analyses have been done to select abnormal event sequences, and to ensure that all potential consequences are within project guidelines. The paper deals with the work done for the tritium systems. A bottom-up methodology based on component level failure mode and effect analysis has been applied to point out accident initiators. Once possible accident sequences have been identified, detailed deterministic analyses on bounding events confirmed that the accidents in tritium plant are not a concern from a safety point of view. The no-evacuation goal of ITER-FEAT is attained also for accidents where ‘ultimate safety margin’ are challenged, as in case of hydrogen- air reactions in cold box or in hard shell, enclosing the process equipment of the isotope separation system.

03/00630 The design features of the HTR-10 Wu, Z. et al. Nuclear Engineering and Design, 2002, 218, (l-3), 25-32. The 10 MW High Temperature Gas-cooled Test Reactor (HTR-10) is a modular pebble bed type reactor. This paper briefly introduces the main design features and safety concept of the HTR-10. The design features of the pebble bed reactor core, the pressure boundary of the primary circuit. the decay heat removal system and the two independent reactor shutdown systems and the barrier of confinement :rre described in this papel

03/00631 Thermal resistance contributions of oxides growth on lncoloy 800 steam generator tubes tglesias, A. M. and de1 C. Raffo Calderon, M. A. Nuclear Engineering md Design, 2003, 219. (l), l--10. The primary and secondary circuits of nuclear power plants have different water chemistries, corrosion product sources, temperatures *and flow rates. All these parameters promote the growth or deposition of oxides of different compositions and morphologies on the surfaces of the steam generator tubes. This paper presents a methodology to evaluate the relative contributions to the total heat transfer resistance due to the different oxide layers. The values obtained from a sample of Alloy X00 tube at room temperature are similar to those encountered in

03/00634 Activities on target fabrication and injection toward laser fusion energy in Japan Norimatsu, T. et al. Fusion Engineering and Dcslgn, .3002. 63-64, 587- 596. Target-related activities to demonstrate ignition and burn were summarized. Fabrication of foam shells with a gas barrier by emulsion process, understanding of centering mechanism m the emulsion process, coating of organic photovoltaic cell to reduce initial imprint are described. Cooling-induced deformation (CID) of shells was studied and found to be important for thin shells. Results on magnetic levitation, injection and tracking that are necessary lo provide targets to the firing position are mentioned.

03/00635 Decision-making of nuclear energy policy: application of environmental management tool to nuclear fuel cycle Lee, Y. E. and Koh, K.-K. Energy Policy, 2002, 30, (13), 1151-1161. This study aims to evaluate and estimate the environmental impacts of nuclear fuel cycles and to support the decision-making of nuclear energy policy, relating to a selection of environmentally preferred nuclear fuel cvcle for the environmentallv sound and sustainable development 01 nuclear energy. To achievi this objective, life cycle assessment (LCA) as an environmental management tool is applied to the nuclear fuel cycle alternatives of a once-through fuel cycle, the direct use of PWR spent fuel in CANDU (DUPIC) cycle and recycling with plutonium and uranium recovery by extraction (PUREX) process. The assessments provide a comparison of the environmental impacts of the three nuclear fuel cycle options and the environmentally most significant stages of each nuclear fuel cycle are identified. As a result, the recycling with PUREX process turned out to impose less- significant environmental impact than did the Dl.JPIC <and once- through options. The environmentally dominant stage was found to be mining/milling stage and the most radiologically significant pathway could be an internal exposure. The results are useful for making a decision of nuclear energy policy by an estimation of environmental impacts of nuclear fuel cycle options and the application of LCA to nuclear energy is very significant eco-labeling according to the advent of international standard organization 14 000 series. Finally, this approach also makes it possible to obtain the environmental data relating to the nuclear energy and to examine thle environmental impacts of chemical effluents discharged from a nuclear facility. From this result, therefore, the comparative assessment of nuclear and non- nuclear energy sources including radiological and non-radiological aspects may be further developed.

Fuel and Energy Abstracts May 2003 151