Accelerator and Target Technology for Accelerator Driven Transmutation and Energy Production (2010)

Since the early 1990’s, accelerator driven systems (ADS) – subcritical assemblies driven by high power proton accelerators through a spallation target which is neutronically coupled to the core – have been proposed for addressing certain missions in advanced nuclear fuel cycles. Institutes throughout the world have conducted numerous programs evaluating the role of ADS in nuclear waste transmutation and energy production. In 1995, the National Research Council (NRC) issued a report on transmutation technologies, which included an evaluation of one ADS concept that was under study at that time: a large-scale system that proposed using a ~100-MW accelerator to drive a thermal, molten salt subcritical core. The NRC recognized the numerous complexities associated with the system, including the fact that, at that time, much of the high-power accelerator technology required for that ADS system had yet to be demonstrated. Consequently, the NRC report did not look favorably upon ADS. In 1999 the US Congress directed the DOE to evaluate Accelerator Transmutation of Waste (ATW) concepts and prepare a “roadmap” to develop the technology. This roadmap identified the technical issues to be resolved, assessed the impact of ATW on high-level waste disposition, and estimated the scale and cost of deploying ATW to close the fuel cycle. It also recommended that Congress fund a $281M six-year program of trade studies and R&D on key technology issues that would support a future decision on technology demonstration. From 2000 to 2002, the DOE sponsored the Advanced Accelerator Applications (AAA) program to investigate the use of ADS in “closed” nuclear fuel cycles. In 2003 the AAA program transitioned into the Advanced Fuel Cycle Initiative, and DOE-sponsored ADS research ceased, except for the continuation on a few international collaborative efforts. A number of factors contributed to this decision, primarily the small expected growth in commercial nuclear power which “negated” the principal driver for ATW/AAA, i.e., destruction of transuranics and problematic fission products assuming that there would be essentially no new construction of commercial reactors. Outside of the USA, research into ADS for both transmutation and power generation has not only continued but accelerated. In 2001 the European Technical Working Group evaluated the state of ADS technologies and recommended the construction of an experimental ADS. In 2002 an expert group, convened by the Organization for Economic Cooperation and Development’s Nuclear Energy Agency (OECD/NEA), authored a comprehensive report entitled Accelerator Driven Systems (ADS) and Fast Reactors in Advanced Nuclear Fuel Cycles. In it, they conclude, “On the whole, the development status of accelerators is well advanced, and beam powers of up to 10 MW for cyclotrons and 100 MW for linacs now appear to be feasible. However, further development is required with respect to the beam losses and especially the beam trips to avoid fast temperature and mechanical stress transients in the reactor.” Technology demonstration is now gaining momentum with the Belgian government’s announcement of its intention to construct MYRRHA, an 85-MW prototype ADS at the Belgian Nuclear Research Centre, SCK•CEN. The government has committed to finance 40% of the construction cost, and is expending €60M over the next five years to advance the design in preparation for a construction start in 2015. In addition, there are recent indications the Chinese and Indian governments are considering construction of prototype ADS facilities of similar scale. ADS technology development programs exist in Europe, Japan, South Korea, India, China and Russia which are focused on both waste transmutation and power generation.