Modeling of Am-241 as an alternative fuel source in a radioisotope thermoelectric generator

Journal Article · Mon Nov 01 00:00:00 EDT 2021 · Nuclear Engineering and Design

DOI:https://doi.org/10.1016/j.nucengdes.2021.111495· OSTI ID:1832379

Dustin, J. Seth ^[1]; Borrelli, R. A. ^[2]

---

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Univ. of Idaho, Idaho Falls, ID (United States)

Radioisotope thermoelectric generators (RTGs) have been utilized in the USA to power satellites and space exploration equipment for over half a century. In our preceding paper, Dustin and Borrelli (2021), we assessed the performance of ²⁴¹Am as an alternative to ²³⁸Pu by modeling the specific decay-heat and gamma spectra of several potential radioisotopes in SCALE-ORIGEN, and comparing these with ²³⁸Pu An analysis of heat output, heat stability, safety, availability and required mass showed that of the isotopes reviewed, ²⁴¹Am had the greatest potential for replacing ²³⁸Pu, with additional design considerations. In our current work, we have assessed radiation transport for two configurations of an ²⁴¹Am powered Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), due to the potential health effects for operators, fabricators, and others with the potential to be exposed to neutrons and lower energy gamma rays. We have modeled the use of americium as a fuel source replacement for plutonium in current MMRTG designs. The assessment has been performed using MCNP6, in terms of neutron and gamma emissions that might interfere with sensitive equipment and power system production. The radiation transport behavior in terms of dose rate of the ²⁴¹Am fueled models is compared with that of a ²³⁸Pu fueled model. Finally, additional work was performed to validate modeling simplifications with regards to thermocouple material configurations.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: National Aeronautics and Space Administration (NASA); USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1832379
• Report Number(s): LA-UR--21-21839
• Journal Information: Nuclear Engineering and Design, Journal Name: Nuclear Engineering and Design Vol. 385; ISSN 0029-5493
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS