&gt; Producing even a little heat with fusion produces a lot of nasty radiation. As in kill everyone in the unsheilded room within a few seconds.<p>This is greatly exaggerated.  The amount of excess heat they claimed to observe was really quite small, and D-D fusion produces a relatively weak neutron flux [0].  I&#x27;m not saying some shielding wouldn&#x27;t have been a good idea, but instant death?  No.<p>[0] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fusion_power#Deuterium" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fusion_power#Deuterium</a>