Identification of Potential Waste Processing and Waste Form Options for Molten Salt Reactors

Abstract

B.J. Riley, (a) J. McFarlane, (b) G.D. DelCul, (b) J.D. Vienna, (a) C.I. Contescu, (b) L.M. Hay, (a) A.V. Savino, (a) H.E. Adkins, (a) (a) Pacific Northwest National Laboratory

Assessment of Adequacy and Completeness of Standards Endorsed by Regulatory Guides to Molten Salt Reactors

“…Following fission of the different fuel types, a variety of radioactive gaseous FPs or nonradioactive gases/vapors mixed with radionuclides could be released, including particulates, aerosols, reactive gases, hydrogen (e.g., tritium), water, nitrogen, oxygen, and noble gases (e.g., xenon, krypton). These radionuclides will be generated continuously during reactor operation, and releases must be maintained below regulatory limits [21].…”

“…FP decay back toward stability is likely to be a reductive process, so redox control will be time dependent [17]. Polishing systems can be run in either continuous or batch-style processing routes in which FPs can be removed during operation or at the reactor's end of life (or end of batch) [21].…”

“…By comparison, the typical MSR backend waste materials will be more complex. Typical generic MSR waste streams include the following [21]:…”

Molten salt reactors and electrochemical reprocessing: synthesis and chemical durability of potential waste forms for metal and salt waste streams

“…form evaluation identified metal and salt waste forms as the least developed and identified the need to develop functional requirements for disposal of these wastes with respect to DOE repository design concepts [12]. Standard test methods [13][14][15][16], property databases [13,17], and models [18,19] have been developed over many decades to qualify waste forms for longterm disposal in a HLW repository.…”

“…Metal waste forms are, therefore, a good candidate to contain NMFPs as well as steel, zirconium, and a limited amount of actinide elements that are entrained into the metal waste stream, in a compact, robust, and degradation resistant waste form. Economically viable pathways for the disposal of metal waste streams include size reduction (via melting or compaction) or recycling [11,12].…”