Page 3 - Demo

The management and processing of spent nuclear fuel (SNF) is complex and can follow three main paths, what we present here is a path of Partitioning and Transmutation (P&T) [8]; the other two paths are: (1) The once-thru cycle (OTC), note this is not a cycle per se, fuel where spent fuel is sent to storage without reprocessing apart from packaging to isolate from biosphere. (2) The reprocessing fuel cycle (RFC) with recycling of plutonium and some uranium using PUREX. The OTC and RFC method reached industrial scale maturity, P&T is currently in the R&D stage. Partitioning will remove the TRU’s from the high level liquid waste (HLLW) prior to vitrification with the potential of removing long-lived fission products as well, and transmutation converts waste into stable nuclei or less radiotoxic nuclei. It should be noted that following the OTC approach commits us to license two repositories of the size of Yucca Mountain size for spent fuel and one of the same size for high-level waste worldwide [8], [9].
The principle and motivation for transmutation is shown in Fig. 1 [10], [11]. Overall, the partitioning and transmutation of the SNF allows 100x volumetric reduction and 1000x reduction in duration required for storage by first separating plutonium and uranium (by PUREX to be reused as MOX fuel or in fast reactors), and then transmuting the long-lived MA into short-lived FP (fission products). This focus of transmutation on MA simplifies the process, as the isotope separation of MA is not necessary, as they all needed to be and are transmuted. The underlying process which governs transmutation is a neutron irradiation with two distinct results: fission or neutron capture. Fission usually occurs for odd isotopes of actinides and may be exemplified by n+241Am134Cs(2 y) + 105Ru(36 h) + 2 n + 200, neutron capture is exemplified by n+99Tc (220,000y)100Tc (16 s beta decay)100Rh or n+241Am(433 y)242Am (16h). As can be seen in Fig. 1, MA transmutation and incineration will decrease the lifetime of the MA