NOTICE This document contains information of a preliminary nature. It is subject to revision or correction and therefore does not represent a final report.

No abstract

No abstract

This study examines design alternatives for molten-salt breeder reactors (MSBRs) with breeding ratios near 1.0 to evaluate their nonproliferation characteristics. Only those systems are examined for which sufficient information exists to describe adequately the power plant system characteristics in terms of both practicality as a source of electricity and susceptibility to diversion of special nuclear material (SNM). In this precursory study evaluating performance and nondiversion features, various candidate systems have been examined with the following results: (1) molten-salt reactors could eliminate the transport requirements of SNM to or from the reactor for long periods of time and make the extraction of SNM from the reactor inventory difficult; (2) two candidate MSR configurations, the CeF 3 processing scheme and the scheme with no chemical processing, can be highly resistant to diversion but cannot be classed as diversion-proof; (3) two additional systems, less resistant than the two above, are the reductive-extraction process without Pa isolation and the salt distillation process; and, (4) the system based on the reference MSBR, requiring salt fluorination is significantly less resistant to diversion than a system without fluorination. Diversion-resistant MSBRs, if developed, might afford resistance to diversion of SNM comparable to solid-fueled reactors without fuel reprocessing and would require less uranium for deployment and operation. * Note Added in Proof: Since this report was written, a molten-salt system was identified that may be remarkably resistant to materials diversion as well as having a conversion ratio near 1.0. This system uses a denatured fuel mixture of 233 U-238 U; processing consists only of removing fission products. These results are only tentative and require more analysis before the described properties can be confirmed. * Plutonium, if any, in the fuel will exist as PuF 3 and will also be retained on the column. It may be economical to recover this when the CeF 3 is ultimately returned with the spent fuel from the reactor facility. ** UF 3 and EuF 3 will be partially removed by the column; UF 4 and EuF 2 will not. * The process would probably leave any oxide contamination in the still bottoms, but this oxide may be combined with (and render undistillable) some uranium and protactinium.

I~ liability or responSJ.Dility for the accuracy, completeness or uaefulnes:s Or any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights .