Simplified models for pebble-bed HTR core burn-up calculations with Monteburns2.0

Abstract This paper aims at comparing some simplified models to simulate irradiation cycles of Pu fuelled pebble-bed reactors with Monteburns2.0 © code. As a reference core, the PBMR-400 (proposed in the framework of the EU PUMA project, where this kind of core fuelled by a Pu and Pu–Np fuel has been studied) was taken into account. Pebble-bed High Temperature Reactor (HTR) cores consist of hundreds of thousands pebbles arranged stochastically in a cylindrical or annular space and each pebble is a single fuel element, and it is able to reach ultra-high burn-ups, i.e. up to 750 GWd/tHM (for Pu-based fuels). Additionally, pebble-bed cores are characterised by a continuous recirculation of pebbles from the top to the bottom of the core. Modelling accurately with current computer codes such an arrangement, in order to predict the behaviour of the core itself, is a very difficult task and any depletion code specifically devoted to pebble-bed burn-up calculation is not available at the moment. Because of limitations of the most common current MCNP-based depletion codes as well as huge calculation times, simplified models have to be implemented. After an analysis of the literature available on pebble-bed models for criticality and burn-up calculations, a preliminary assessment of the impact of different kind of simplified models for a Pu-Np fuelled Pebble-Bed Modular Reactor (PBMR), proposed in the framework of the EU PUMA project, is shown, particularly as far as burn-up prediction with Monteburns2.0 © code is concerned.

[1]  U. Ohlig,et al.  V. S. O. P. ('94) Computer Code System for Reactor Physics and Fuel Cycle Simulation , 1994 .

[2]  Guglielmo Lomonaco,et al.  Analysis of Pebble-Fueled Zone Modeling Influence on High-Temperature Reactor Core Calculations , 2009 .

[3]  J. F. Briesmeister.  MCNP-A General Monte Carlo N-Particle Transport Code , 1993 .

[4]  Joshua J. Cogliati,et al.  METHODS FOR MODELING THE PACKING OF FUEL ELEMENTS IN PEBBLE BED REACTORS , 2005 .

[5]  Forrest B. Brown,et al.  CONVERGENCE TESTING FOR MCNP5 MONTE CARLO EIGENVALUE CALCULATIONS , 2007 .

[6]  Masayuki Nakagawa,et al.  Continuous Energy Monte Carlo Calculations of Randomly Distributed Spherical Fuels in High-Temperature Gas-Cooled Reactors Based on a Statistical Geometry Model , 1996 .

[7]  Masayuki Nakagawa,et al.  New Sampling Method in Continuous Energy Monte Carlo Calculation for Pebble Bed Reactors , 1997 .

[8]  Guglielmo Lomonaco,et al.  The Use of Th in HTR: State of the Art and Implementation in Th/Pu Fuel Cycles , 2009 .

[9]  A. G. Croff,et al.  User's manual for the ORIGEN2 computer code , 1980 .

[10]  Guglielmo Lomonaco,et al.  Comparison among MCNP-based depletion codes applied to burnup calculations of pebble-bed HTR lattices , 2010 .

[11]  E. Liniger,et al.  Random loose packings of uniform spheres and the dilatancy onset. , 1990, Physical review letters.

[12]  Danny Lathouwers,et al.  Effects of random pebble distribution on the multiplication factor in HTR pebble bed reactors , 2010 .

[13]  J. Oppe,et al.  MODELING OF CONTINUOUS RELOAD HTR SYSTEMS BY THE PANTHERMIX CODE SYSTEM , 2001 .

[14]  Guglielmo Lomonaco,et al.  A Critical Review of the Recent Improvements in Minimizing Nuclear Waste by Innovative Gas-Cooled Reactors , 2008 .

[15]  R. F. Benenati,et al.  Void fraction distribution in beds of spheres , 1962 .

[16]  J. Lieberoth,et al.  Neutron Streaming in Pebble Beds , 1980 .

[17]  Guglielmo Lomonaco,et al.  Assessment of LWR-HTR-GCFR Integrated Cycle , 2009 .

[18]  Abderrafi M. Ougouag,et al.  A Preliminary Study of the Effect of Shifts in Packing Fraction on k-effective in Pebble-Bed Reactors , 2001 .

[19]  H. Chang,et al.  MONTE CARLO METHOD TREATMENT OF STOCHASTIC GEOMETRY IN A PEBBLE BED REACTOR , 2005 .

[20]  D. I. Poston,et al.  User's manual, version 1.00 for Monteburns, version 3.01 , 1998 .

[21]  E. Bende.  Plutonium Burning in a Pebble-Bed Type High Temperature Nuclear Reactor , 2000 .