Helium-3 Applications and Recovery Techniques

Abstract

Helium-3 is a rare and highly important isotope of helium, with a wide range of applications in various industries, such as energy production, cryogenic systems, and medical research. Helium-3 holds significant potential in the energy sector, in addition to its other uses (e.g., neutron detection, dilution refrigerators, ultralow temperature physics, and aneutronic fusion). As a non-radioactive isotope, it is an ideal fuel for fusion reactors when fused with deuterium, offering the advantage of not producing neutrons, unlike deuterium–tritium fusion, which is more commonly explored today. While still in the experimental stage, the ability to contain such energy in a reactor’s containment chamber could make it a viable energy source. Helium-3 is produced as a byproduct of tritium decay in CANDU reactors’ cover gas. The main goal of this article is to enrich the Helium-3 content in a mixture of ³He and ⁴He, similar to the composition of cover gas, up to 10–15% ³He. The originality and innovative aspect of this article lie in the development and characterization of a helium-3 pre-enrichment technology based on chromatographic columns and gas permeation processes. This, combined with a cryogenic distillation process, will form a comprehensive technology for helium-3 recovery from the cover gas of a CANDU-type nuclear reactor. In this context, we present two methods for helium isotope separation: one based on gas chromatography and the other on cryogenic distillation. The method will be developed and optimized for medium-throughput isotope separation facilities, such as those required for the Cernavoda Nuclear Power Plant. In the first part, we present a method for investigating and evaluating the separation and recovery of helium isotopes using gas chromatography. In the second part of the article, we describe the steps undertaken at the ICSI site regarding the development of a technology for helium-3 recovery from fusion reactor cover gas and tritium storage containers.