A friend of my who used to consult for the NRC wrote me an e-mail in January, 2010, about thorium reactors. He said:
"I have followed this technology for some years with interest. It has merits and one great demerit - it is very costly - at least twice the cost of most renewables. So why go this route? The so called renaissance of uranium reactors has become a fiasco. The Finnish project with Areva was to cost $2500 per Mwe for the first prototype,with $1200 per Mwe in the following standardized units.The reality is 3 years behind schedule, 77% over budget with no hope of completion at less than a 100% overrun, and standardized successors now priced at $5000 per Mwe, four times the hoped for cost. There is no reason whatever to claim thorium based reactors will be any cheaper. We cannot afford to waste precious time and money on nuclear, but should have a crash implementation of commercializing renewables like wind and solar thermal electric."