1. In the extremely hot conditions of a nuclear bomb, helium 3 is rapidly converted into tritium (with emission of a positron and a neutrino for each nucleus) by the X-rays.

2. Helium 3 is a cryogenic liquid, while lithium 6 deuteride is a solid at room temperature. This creates a storage problem.

3. Helium 3, although stable, is not very dense, even in liquid form. Lithium 6 deuteride releases more tritium per unit volume under nuclear explosion than does liquid helium 3. On the other hand, helium 3 lasts forever, and does not require periodic reprocessing, but requires continuous refrigeration.

4. It may be the case that the liquid helium 3 could be compressed to sufficient density by the thermal X-rays (on the tampers) to make up for its low original density.

5. The tritium-tritium fusion reaction releases more neutrons than deuterium-tritium fusion, facilitating more complete fission of uranium or plutonium.