1. SYSTEMS AND ENGINEERING TECHNOLOGY INVESTIGATION OF AN INERTIAL CONFINEMENT FUSION-FISSION HYBRID REACTOR Kiranjit Mejer PTNR Research Project 2009 Frazer-Nash Consultancy University of Birmingham

2. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY The Basic Concept  Fusion neutron source D + T → α + n + 17.6 MeV (n energy 14.1 MeV)  Sub critical fission blanket  Neutron multiplier blanket  Reflector Benefits of a Hybrid  Waste transmutation – reducing inventory of HLW  Production of energy  Development of fusion technology  Inherent safety The Fusion-Fission Hybrid Reactor

3. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Laser Inertial confinement Fusion-Fission Energy Engine  Inertial confinement fusion source  Surrounded by Beryllium blanket  Spherical blanket of sub-critical fission fuel  Graphite blanket  Pb-Li first wall coolant  FLiBe (2LiF+BeF 2 ) coolant  Power conversion system Image from ”Thermal and Mechanical Design Aspects of the LIFE Engine” R P Abbot et al, 2009

4. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Multiplication Factor of Be Blanket  Pure 9 Be – 1.85 gcm -3  Peak at 17 cm blanket thickness  Factor ~ 2.06  Pebble packing fraction 60 % - 1.11 gcm -3  Factor ~ 1.81 at 16 cm  Supported by “A Sustainable Nuclear Fuel Cycle Based on Laser Inertial Fusion Energy” Moses et al, 2009

5. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Fuel Blanket Investigation  Below - Energy gain from fission blanket of natural Uranium 19.1 gcm -3 surrounding a Beryllium blanket  Above - Energy gain from fission blanket of pure 238U

6. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Energy Spectrum of Neutrons  Neutron energy entering the fission blanket  ~ 0.05 at 14 MeV  Large proportion at thermal energies  Maxwell-Boltzmann distribution peaks at 0.025 eV  Spectrum of neutrons returning from reflector shows same form

7. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Other Fuel Options radius 1 cm Outer radius 0.5 mmKernel radius 0.3 mm Buffer layer (C) High-densityPyc SiC coated particles embedded in graphite matrix 30% TRISO 70% Carbon  Fuel composition based on graphite pebbles containing TRISO particles Image adapted from http://blogs.princeton.edu/chm333/f2006/nuclear/trisoball.jpg http://blogs.princeton.edu/chm333/f2006/nuclear/trisoball.jpg

8. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Fission blanket energy gain and criticality Fuel optionFission Energy Gaink eff Th-2320.520.033 DU (0.26% 235 U)7.700.396 Natural U16.080.576 LWR Spent Nuclear Fuel 27.600.720 Separated Transuranic Elements 183.140.966 Weapons grade plutonium 2.342

9. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Coolant Effects  First wall coolant Pb 83 Li 17  Primary coolant FLiBe (2LiF + BeF 2 ) 6 Li + n → 4 He + T + Q 7 Li + n → 4 He + T + n’ – Q  Tritium Breeding Ratio (TBR) – ratio of T produced to consumed  For self sufficiency TBR > 1.05  Requires 6 Li enrichment of 50% or more

10. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Project Extensions Improvements to the Model  Geometry – structural materials etc  Fuel blanket compositions  Temperatures  Number of neutron histories  Other fuel fabrication options  Time dependent nature of the reactor - evolution of fuel with breeding from fertile isotopes - flattening power output with 6 Li content

11. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY Summary  Demand for clean, abundant energy and concerns over HLW management have led to renewed interest in the hybrid concept  MCNP modelling has demonstrated the viability of a number of fuel options particularly SNF  Enrichment of 6 Li content in coolants can provide tritium self sufficiency for the reactor  Timescale for LIFE machine large

12. SYSTEMS AND ENGINEERING TECHNOLOGY www.fnc.co.uk

13. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY MCNP Model  Isotropic, monoenergetic neutron point source  Pb-Li first wall coolant  Beryllium multiplier blanket  Fission Blanket  Graphite reflector  Stochastic approach - uses random number generation and reaction cross section data to determine the ‘history’ of a particle  Many histories followed to give a representation of a real world situation

14. © Frazer-Nash Consultancy Ltd 2010. All rights reserved. Confidential and proprietary document. SYSTEMS AND ENGINEERING TECHNOLOGY