In his helpful reply, Dr Storms seemed to indicate that these considerations were getting at something else in addition to the lack of beta particle emission. Here is the gist of what he said:
- Occasionally neutrons are seen, but their levels are very low and their source unknown and unrelated to heat production.
- The radioactivity expected when neutrons interact with their surroundings is easy to detect using a cheap Geiger-Muller counter and has been sought and rarely seen.
- Neutrons are short-lived, with a half-life of ~ 16 minutes, so they must be constantly replenished in a sustained reaction. This is not possible in ordinary materials.
Storms' points have obviously been given some thought, and I hope to learn more about each of them. I understand that he discusses the low levels of neutrons that are occasionally seen in his "Student's Guide" and offers a possible explanation, so I will read that paper first before drawing any conclusions in the present connection.