Introduction to Work Package 4

Safety and Performance for a

New Generation of Reactor

Designs

Tony Goddard

Applied Modelling and Computation Group

Earth Science and Engineering

Imperial College London

Initial Aims and Objectives

• PhD and PDRA training in systems modelling with respect to Gen IV

• Research into modelling fault and severe accident transient behaviour of VHTR and GFR systems

• Link materials performance and detailed heat transfer processes into safety performance research

• Develop the ability to predict the dynamical behaviour of fission products

• To form an overview of hydrogen production using nuclear heat from advanced reactors and comment on design implications

• To work closely with UK industry and international bodies

• Identify gaps in knowledge to supplement the UK contribution to the international programme

Investigators and Projects

‘Strong cross cutting (CC) with other WPs’ • Chris Pain and Tony Goddard (Imperial, CC with WP1) Coupled 3D

asymmetric neutronics/thermal hydraulics for Gen IV fault studies

Multi-scale physics and fluids modelling … to perform 3D whole core spatially coupled

transient studies for a range of faults for VHTR and GFR models… will use the generic

advanced reactor FETCH option implemented.. with a primary research focus on … the

physics and engineering of …selected fault and severe accident sequences.

• Dominique Laurence and Mark Cotton (Manchester, CC with WP1)

Heat transfer in advanced ceramic structures

A PhD student will exploit the database … of advanced RANS models .. focus on optimising

fuel/coolant exchanges for novel VHTR-GFR (gas-cooled) ceramic-prismatic cells in future

reactor designs… explore a variety of innovative designs, such as spiral ribs, or twisted

hexagonal rods

Investigators and Projects

•Robin Grimes (Imperial, CC with WP3) Radiation damage simulations in fuel … develop the ability to predict the dynamical evolution of fission products

in fuel and waste forms subject to displacement damage. …will employ conventional molecular

dynamics and a new multi-time scale simulation approach…. underpinning …..reactor safety

case models for the release of volatile fission products (in particular gas atoms) from fuel.

• Barry Marsden (Manchester, CC with WP2) Graphite issues for Generation IV

To obtain a core life to ~40years as required under Generation IV aims new longer lasting

graphite needs to be developed for VHTR technology .. This will involve the development of

mechanistic models that may be used to predict the irradiation behaviour of new novel graphitic

material from knowledge of the unirradiated microstructure.

Investigators and Projects

• Mike Fitzpatrick and Lyndon Edwards (OU, CC WP2) Review of candidate

metallic materials.

… a very good understanding of the behaviour of the materials (static and dynamic) is

required over the entire scale range from atomic, through micro-structure, to large scale

structures.. the OU will review international work, identify gaps in knowledge

• Ray Allen (Sheffield) Design implications of hydrogen production

A Generation IV reactor, such as the VHTR, is considered an essential element of the

international drive to harness nuclear heat for the zero emission production of hydrogen….,

the Sheffield team will consider in detail the thermodynamic limitations of the available

cycles and the extent to which these impact on the reactor design, particularly in so far as it

places limits on the upper temperature for process use.

Features of activity since October 2005

• Held two WP meetings (hosted Barry) in Manchester – Spring 2006 and

2007

• Meetings useful for new ideas – eg KNOO cfd benchmarking activity

• Good forum for PhD students – supplemented by:

– six young people attended Stuttgart Raphael VHTR course

– Three attended FJ/OH course last year and two to attend 2007

• GenIV systems excellent for originality and research training

• UK becoming ‘inactive’ GIF member has hit stakeholders

• Nonetheless – wider spin-offs for stakeholders from KNOO

Examples of wider UK industry spin-offs

• Increases pool of people familiar with gas

reactor issues – eg graphite materials

issues, whole circuit modelling – MACE

code – and coolant channel flows

• ‘virtual’ reactor – KNOO WP4 3D coupled

nuclear/T/H/structural modelling provides

supportive platform for collaboration with

SULTAN/MOD reactor research

Relations with EC etc

• The commission now has robust frameworks for indirect action

programmes for all six GenIV systems under FP7

• We have ensured that senior figures in the Commission and EURATOM

are aware of KNOO – they want closer contacts

• Need for a UK ‘legal entity’ which could bring KNOO within GIF – better

international contacts for our training and research?

• Only current formal route to GIF is participation in FP6/FP7 indirect action

programmes – several KNOO groups have these links

For our student audience

What are the GenIV systems?

• Compared with Gen III, (~2015), Gen IV systems (~2040) enhanced

sustainability (including full actinide recycling) and enhanced

competitiveness (eg cogeneration of heat and power for process heat,

syn-fuels and hydrogen)

For our student audience

GenIV thermal systems

• VHTR – mainly possible co-generation,

maybe electricity production with high

efficiency, no actinide management, once

through cycle

• SCWR – Supercritical water-cooled

reactor – mainly electricity production

with high efficiency, maybe cogeration,

actinide management with ‘fast’ version.

For our student audience

GenIV fast systems – and MSR

• GFR – Mainly electricity production with

high efficiency/actinide management

• SFR – as for GFR

• LFR - as for GFR

• MSR- Molten salt reactor – full actinide

management; electricity production – also

MSR research links with advanced

reprocessing technology

Summary

• WP 4 off to a good start with good inter-university

relations and links between WPs

• Exciting new research areas emerging

• Gen IV clearly a major research activity in Europe

and we need to find better ways to interact with

this and with GIF

• Spin-offs to current UK industry interests