Thorium: An Alternative Nuclear Future — Professor Bob Cywinski — 21st October 2013.

Professor Bob Cywinski presen­ted a case for the use of thorium in nuc­lear react­ors for power gen­er­a­tion. It was delivered in a manner that was logical and easily under­stand­able, even to the non-scientific mem­bers of our club. In brief the case is set out below.

World energy con­sump­tion is rising. The CO2 emit­ted is caus­ing cli­mate change and global warm­ing. Most experts agree that renew­able sources, even com­bined with effi­ciency sav­ings, cannot meet the demand.

Nuclear power, fuelled by Uranium, provides a low-carbon way to meet energy needs. But there are prob­lems and public res­ist­ance, par­tic­u­larly on issues of safety, waste man­age­ment and pro­lif­er­a­tion. However using thorium as nuc­lear fuel instead of uranium can help to solve all three issues:  thorium react­ors can be run in sub­crit­ical mode: when switched off they stay off;  the waste from Thorium react­ors decays after a few hun­dred years — rather than after hun­dreds of thou­sands; it is very dif­fi­cult to divert a thorium reactor to mil­it­ary use, par­tic­u­larly because little or no plutonium is pro­duced in the fuel cycle.

Additionally the world has a lot of thorium — it is as abund­ant as lead — and it is found widely in polit­ic­ally friendly coun­tries.  Indeed there is suf­fi­cient thorium to provide our energy needs for tens of thou­sands of years. Moreover thorium fuel rods would last for years, rather than months in a reactor, so there is less refuel­ling than with uranium. Equally import­antly, legacy radio­act­ive waste from exist­ing react­ors can be mixed with thorium and burnt as fuel, thereby turn­ing a liab­il­ity into an asset.

This is not just spec­u­la­tion. Thorium react­ors have run in the past for many years. China and India are increas­ing fund­ing for Thorium power. It’s a fast moving field and there is an oppor­tun­ity for the UK to tap into its expert­ise by invest­ing in the research neces­sary to pos­i­tion UK industry to build the new power sta­tions.

This talk intro­duced some of the ways that thorium could be deployed: as a fuel in con­ven­tional react­ors; through molten salt reactor tech­no­logy; and as fuel in an accel­er­ator driven sub­crit­ical reactor (ADSR) or Energy Amplifier in which the neut­rons neces­sary to drive the fer­tile to fis­sion con­ver­sion of thorium, and the fis­sion pro­cess itself are provided by spal­la­tion.

The ADSR is of par­tic­u­lar interest at the University of Huddersfield, where we are devel­op­ing new and advanced accel­er­ator tech­no­logy not only cap­able of driv­ing an ADSR but also provid­ing com­pact accel­er­at­ors for proton cancer ther­apy and med­ical radioiso­tope deliv­ery.

Having listened to the talk the major­ity of our mem­bers saw the use of thorium as a ‘win win’ situ­ation and there were many enthu­si­astic ques­tions from the floor.