Whilst it is certainly not desirable to be bombarded with neutrons,

Er - the neutrons would be intercepted and create heat, that is how fusion is proposed to be harnessed. They would hopefully be all absorbed, but 100% is a tough task master. The alpha particles would be harder to use, if not impossible, as an energy source. So..........

All those dis-used deep coal mines would be a good place to site fusion reactors. The rock & soil would then shield us from alpha particles and stray neutrons, and not overly many microbes would be hurt in the process. But who can put a value on those microbes, we don't even know who they are! But they are reckoned to be there, deep in the rocks. Waiting to be discovered. And might be a lot hardier than homo sapiens.

Ain't no such thing as a free lunch. Don't ya know?