²³⁸Pu can be used as the heat source in radioisotope thermoelectric generators for deep space exploration, while it is currently in shortage because of the suspension of ²³⁸Pu production in the USA and Russia for many years. Two possible scenarios for the production of ²³⁸Pu as a byproduct in a molten salt fast reactor (MSFR) are assessed in this work. For the first scenario, the MSFR is started with low-enriched uranium (LEU), and neptunium is extracted from the fuel salt and then fed into the fertile salt of thorium for high-purity ²³⁸Pu production. For the second scenario, the ignition material for the MSFR is ²³³U, and highly purified ²³⁸Pu is produced by directly extracting plutonium from the fuel salt. The simulated results indicate that on average 15.48 kg ²³⁸Pu with the quality (ratio of ²³⁸Pu mass to total mass of Pu isotopes) larger than 98.6% can be produced per year during a 60-year operation for scenario I. In parallel, 8.31 kg ²³⁸Pu with the quality larger than 91.9% can be produced annually for scenario II. The ²³⁸Pu production has a small impact on the neutronic performance of the core for the two scenarios except that bred ²³⁸U is reduced by 922 kg for scenario I and by 261 kg for scenario II during the 60-year lifetime. The ²³⁸Pu production has a very tiny effect on the radiotoxicity of discharged nuclear fuel for scenario I, while it can reduce the total radiotoxicity of discharged nuclear fuel by three times for scenario II.

²³⁸ Pu可以用作放射性同位素热电发生器中用于深空探测的热源，但由于美国和俄罗斯多年以来²³⁸ Pu生产的停产，目前短缺。在这项工作中，评估了在熔融盐快堆（MSFR）中生产副产物²³⁸ Pu的两种可能方案。对于第一种情况，MSFR首先从低浓铀（LEU）开始，然后从燃料盐中提取n，然后将其送入th的可育盐中，以高纯度生产²³⁸ Pu。对于第二种情况，MSFR的点火材料为²³³ U，高度净化的为²³⁸Pu是通过直接从燃油盐中提取p来生产的。模拟结果表明，对于方案I，在60年的运行期间，每年平均可以生产出15.48 kg ²³⁸ Pu，质量（²³⁸ Pu质量与Pu同位素总质量之比）大于98.6％。平行的是8.31方案II每年可生产质量大于91.9％的kg ²³⁸ Pu。在这两种情况下，²³⁸ Pu的产量对堆芯的中子学性能影响不大，不同的是，在60年的寿命中，情况I的繁殖的²³⁸ U减少了922 kg，情况II的减少了261 kg。在²³⁸Pu生产对方案I排放的核燃料的放射毒性影响很小，而对于方案II则可将排放的核燃料的总放射毒性降低三倍。