Per Peterson on Pebble Bed Reactors Status

Status and Progress for the Pebble-Bed Advanced High
Temperature Reactor (AHTR) by Per Peterson Mar 2009 [53 page pdf]

Overview of intermediate and long term nuclear energy options
* Modular PB-AHTR design
900 MWth / 410 MWe
Core power density 20 – 30 MW/m3
Core inlet/outlet temps 600°C/704°C
Uses available ASME Section III Materials

* Modular PB-AHTR development

Only 1% of the cost of nuclear plant construction in the USA is for natural resources ($35/KW for natural resources – metal and concrete, out of recent $3500/KW construction cost).

Three primary options exist for long-term, sustainable nuclear energy systems

• Fast neutron spectrum reactors
– Uranium-238 based fuel cycle
– Increased fission/capture probability (good neutron economy)
– Large transuranic inventories and complex reactivity control
• Thermal neutron spectrum reactors
– Thorium-232 based fuel cycle
– Requires highly efficient neutron economy (liquid fuels best)
– Small transuranic inventories and simple reactivity control
• Fission/fusion thermal spectrum hybrid reactors
– Uranium-238 or Thorium-232 based fuel cycle
– Abundant neutrons
– Small transuranic inventories and simple reactivity control
– Requires workable fusion power source

Comparison of PB-AHTR with the PBMR:
– 2 x power output per reactor
– ~30 MWth/m^3 core power density versus 4.8 MWth/m^3
– large reduction in vessel size
– atmospheric pressure operation
– 4 x reduction in spent fuel volume per unit of electricity/process steam
– maximum fuel temperature during transients/accidents reduced from 1600°C to 1000°C