180 likes | 315 Views
The UK ADSR programme. Roger Barlow FFAG08 Manchester, 4 th September 2008. History. BASROC/CONFORM “Basic Technology” project for nsFFAGs Funded on the basis that nsFFAGs were an exploitable technology: we can build better+cheaper accelerators and open up lots of new applications
E N D
The UK ADSR programme Roger Barlow FFAG08 Manchester, 4th September 2008
History BASROC/CONFORM “Basic Technology” project for nsFFAGs Funded on the basis that nsFFAGs were an exploitable technology: we can build better+cheaper accelerators and open up lots of new applications • Build EMMA as proof of principle • Design PAMELA as a flagship application • Look for other applications ‘from Archaeology to Zoology’ UK ADSR Programme
Application #2ADSRs Spallation Target Accelerator Driven Subcritical Reactors “Manifestly Safe” Used for power and for waste transmutation Can use Thorium as fuel Accelerator Core UK ADSR Programme
Thorium Fertile, not fissile 232Th +n 233U • Much smaller waste problems (no long-lived actinides) • Proliferation resistant • No 235U equivalent • Fissile 233U contaminated by ‘too hot to handle’ 232U • Abundant • Thoria – ThO2 – has high melting point UK ADSR Programme
Energy Amplifier (Rubbia) Idea has been around for years Nobody’s built one yet! Feeling is that the accelerator is the weak point. Also MYRRHA, KURRI and others UK ADSR Programme
Past/Present Safer? But our reactors are safe… Waste problem? But we’ve solved it… Present/Future Increased awareness of power problem Global warming Fuel prices Global politics Hostility to conventional Nuclear Power continues Interest from Research Councils and individuals UK interest UK ADSR Programme
What energy do we need? Variation with proton energy of: (i) the neutron multiplicity np (ii) neutron yield per unit energy of incident proton (np/Ep) (Calculated using using MCNPX) The energy gain of an ADSR is directly proportional to np/Ep. Clearly there is little need for proton energies greater than 1GeV Taken from Bob Cywinski UK ADSR Programme
Accelerator requirements Proton Energy ~ 1 GeV For 1GW thermal power: • Need 3 1019 fissions/sec (200 MeV/fission) • 6 1017 spallation neutrons/sec (k=0.98 gives 50 fissions/neutron) • 3 1016 protons/sec (20 spallation neutrons each) Current 5 mA. Power = 5 MW Compare: PSI proton cyclotron: 590 MeV, 72 MeV injection 2mA, 1MW UK ADSR Programme
Specification Synchrotron Current far too high. Complicated (ramping magnets) Cyclotron Energy too high for classical cyclotron. On the edge for other types FFAG Looks like the answer Similar to proton therapy except higher current and no need for variable energy extraction Very similar to neutrino factor proton driver Linac Can do the job. But VERY expensive UK ADSR Programme
Achieving high current Frequency must sweep (factor ~2) Need high duty cycle: • Will not achieve cyclotron-like 100% but have to get within an order of magnitude • Need to accelerate several pulses at slightly different energies with the same sweeping frequency • Need several RF frequency systems (in same cavity or separate cavities) UK ADSR Programme
Reliability • No long shutdowns – lose money • No unplanned shutdowns – lose money and customers • Spallation target runs hot. If beam stops, target cools and stresses and cracks: no more than 3 trips per year Cars and planes achieve this… UK ADSR Programme
Achieving reliability • Component Underrating • Redundancy (e.g. Ion source) • Fault Tolerance • Scheduled inspection and replacement programme Has to be integrated into the design UK ADSR Programme
Reliability and RF RF in a linac: Many cavities. Failure of one does not kill beam. Just gets slightly less energy RF in an FFAG: many cavities Failure of one should not kill beam Just gets slightly less energy, or takes slightly longer to accelerate Unless HNJ scheme is used. Probably ruled out UK ADSR Programme
The ultimate redundancy Could have several (3) accelerators for one reactor core If FFAGs are really as cheap as we’re promising UK ADSR Programme
UK Activities • Grouping of interested people (accelerator scientists, reactor engineers, economists..) • Held 2 1-day workshops this year • Couple of small projects (EPSRC funded) to look at possibilities • Increasing funding opportunities anticipated • Upcoming 3 day workshop here, next week UK ADSR Programme
Forthcoming… Formation of the Thorium Energy Amplifier Association: Universities and labs and industry A research consortium aimed at • Networking (website, workshops) • Sharing knowledge, within and outside UK • Collaborative response to funding opportunities • Design of a Thorium ADSR, aimed at power generation with transmutation as bonus. FFAG is baseline accelerator UK ADSR Programme
Conclusions Things are moving fast. Two years ago my worry was that no-one wanted to know. Today my worry is that we’re going to get trampled in the rush. UK ADSR Programme