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

03/02270 Time-dependent neutron transport in a semi- infinite random medium

The time-dependent neutron transport in a semi-infinite random medium of binary Markovian mixture with linear anisotropic scattering is proposed. A formalism, developed to treat radiative transfer in statistical mixtures, is used to obtain the ensemble-averaged solution. The average reflectivity, radiant energy and net flux are computed for the specular-reflecting boundary. Results are obtained for isotropic and anisotropic scattering.

03/02271 Two-group interfacial area transport in vertical air-water flow I. Mechanistic model Fu. X. Y. and lshii. M. Nuclrur Enginwriq und Design. 2003. 219, (2), 143 16X. The prediction of the dynamical evolution of interfacial area concentration is one of the most challenging tasks in two-fluid model application. This paper is focused on developing theoretical models for interfacial area source and sink terms for a two-group interfacial area transport equation. Mechanistic models of major fluid particle interaction phenomena involving two bubble groups are proposed, including the shearing-off of small bubbles from slug/cap bubbles, the wake entrainment of spherical/distorted bubble group into slug/cap hubblc group, the wake acceleration and coalescence between slug/cap bubbles. and the breakup of slug/cap bubbles due to turbulent eddy impacts. The existing one-group interaction terms are extended in considering the generation of cap bubbles, as well as different parametric dependences when these terms are applied to the slug flow regime. The complete set of modeling equations is closed and continuously covers the bubbly flow, slug flow, and churn-turbulent flow regimes. Prediction of the interfacial area concentration evolution using a one-dimensional two-group transport equation and evaluation with experimental results are described in a companion paper.

03/02272 Two-group interfacial area transport in vertical air-water flow II. Model evaluation Fu, X. Y. and lshii, M. NLI~/~CIT Engineering andDesign. 2003. 219, (2). I69 ~190. In a companion paper, mechanistic models of major fluid particle interaction phenomena involving two bubble groups have been proposed. The prediction of interfacial area concentration evolution using the one-dimensional two-group transport equation and evalu- ation with experimental results are performed in the paper. These evaluations are based on solid databases for a 2-inch air-water loop with sufficient information on the axial development and the radial distribution of the local parameters. Model evaluation strategies are systematically analysed. The predictions for the interfacial area concentration evolution demonstrate satisfactory accuracy. The pro- posed model predicts a smooth transition across the bubbly-to-slug flow regime boundary and demonstrates mechanisms for the gener- ation and development of the cap/slug bubble group. The two-group interfacial area transport equation covers a wide range from bubbly, slug, to churn turbulent flow regimes for adiabatic air-water upward flow in moderate diameter pipes. The generality of the interfacial transport model is also discussed.

03/02273 U.S. accelerator-driven transmutation of Waste $TT!, program objectwes, and technology development

Van Tuyle. G. J. (‘I ~1. Progre.s.s in Nuclear Energ.r, 2002, 40. (34), 357- 364. The U.S. Program to evaluate accelerator-driven systems for transmut- ing problematic, long-lived nuclear waste stream components was initiated during fiscal year 2000, based largely on the Accelerator- driven Transmutation of Waste (ATW) Technology Development Road Map developed during 1999. The Road Map (DOEIRW-0519) effort provided a long-range plan, involving technology development, demonstration, and deployment, as well as a recommended initial effort to evaluate the technology options for five or six years. This paper summarizes the ATW Research and Development Plan currently in draft form, Technology Readiness Levels (TRLs), which are based in part on a system used by the U.S. National Aeronautics and Space Administration in determining levels of flight readiness, was developed for use in assessing and advancing technologies relevant to waste transmutation. Based on TRLs and other considerations, the Program is screening technology options and prioritizing the long-term research and development effort. A top-level schedule illustrates the efforts planned to advance the important technology options in preparation for integrated system tests.

Economics, policy. supplies, forecasts

03lO2274 Design and full scale test of the fuel handling system Liu, J. G. er (I/. h’rrclcur hginrvri~~g turd Oc,\ig~z, 2002, 21X. ( I 3). I69 178. In the 10 MW High Temperature Gas-cooled Reactor-Test Module (HTR-10) fuel elements move through the core driven by gravity. To reach their design burn-up the fuel elements are re-shuttled five times. This transportation outside the core is mainly achieved pneumatically. Although, adopting the international experience at design and operation of similar systems some key components were improved so that the fuel handling system (FHS) becomes simpler and more reliable. The improved components were tested in full-scale testing facilities. The debugging test and the first loading operation for the FHS indicate that the FHS meets the demands of the HTR-IO. In this paper, the functions, design parameters, technological processes, main components and design characteristics of the FHS are described in detail. The flow schemes, design parameters of the full-scale testing facilities and the experimental results are briefly introduced.

03/02275 Economic analysis of a 2x200 MW nuclear heating reactor for seawater desalination by multi-effect distillation (MED) Tian, L. PI cl/. Desulinution, 2003, 152, (I-3). 223-228. A nuclear heating reactor (NHR) was designed with a number of advanced and innovative features, including integrated arrangement, natural circulation, self-pressured performance, hydraulic control rod drive and a passive safety system. The engineering project feasibility of 200 MW(t) nuclear heating reactor (NHR200) for the district heating in many northern cities of China has always been carried out by INET since the prototype NHR5 was constructed in 1989. The redesign of 2x200 MW(t) nuclear heating reactor (double NHR200) as a heat source heating to a site in Shenyang city, Liaoning province, has been finished recently. This paper presents an economic feasibility analysis of 2x200 MW nuclear heating reactor for seawater desalination by multi-effect distillation (MED) with a 320000 msiday freshwater production plant in an assumed site in the coastal area of north Africa, which total capital investment cost for double NHRZOO was adjusted based on those of original NHR200 seawater desalination plant under its structure redesign. The result indicated that the levelized discounted production of water cost is $0.87/m3, which is lower than that of NHR200 seawater desalination plant. Four sensitive factors for the cost of water desalination were analysed and compared. The discount/interest rate is one of the factors that has the greatest effect on the water cost. Its water coat is $0.71/m’ while the discount/ interest rate is S%, which can bear the economical comparison with a usual coal-fired or oil-fired seawater desalination plant. Therefore, the double NHR200 seawater desalination system provides a very attractive economically solution to satisfy the demand of seawater desalination energy without contributing to increasing environmental pollution and greenhouse gas emissions. Other factors that have effect on the water cost are purchased electricity cost, capital investment and fossil fuel price.

03/02276 Feasibility study of the IE-SASW method for nondestructlve evaluation of containment building structures In nuclear power plants Kim, D. S. er nl. Ntrclenr Engineering crnd Des@. 2003. 219, (2). 705 712. The IE-SASW method, a combination of impact-echo (IE) acoustics with spectral analysis of surface waves (SASW), is proposed as a newly developed non-destructive testing method in concrete structures. This feasibility study examines the IE technique and uses elastic P-wave velocity data as measured from the SASW method on concrete members in nuclear power plant containment structures. It was shown that both the thickness of the concrete specimens used in this study and the depth of the introduced defects (i.e. voids) could be identified by the IE-SASW method. In contrast, the reinforced steel bar itself could not be identified by the IE-SASW method. Additionally, GPR (ground penetrating radar) techniques were used to examine the same speci- mens in order to establish some level of performance and reliability to compare with the performance of the IE-SASW method. The GPR method provides an objective and reliable image corresponding to the reinforced steel bars. The experimental studies show that it is more feasible to use the IE-SASW method rather than GPR to detect voids that were positioned beneath the steel reinforcing bars in the concrete specimens.

03102277 Future HTGR developments in China after the criticality of the HTR-10 Zhang, Y. and Yu. S. Nuclzur Oz,cirtcc~rin~ iin</ IIc.v&!n, 2002. 718. I 1~ 3). 249-257.

374 Fuel and Energy Abstracts November 2663