In his blog Handl reassures us that he's not the first one trying to build a DIY nuclear reactor.
The result he was going for must have been something like Olaf Brzeski's installation 'Little Boy': a livingroom nuclear explosion.
Olaf Brzeski, 'Little Boy' (detail) (2006)
[Brzeski's work 'Dream - Spontaneous Combustion' (2008) can be seen in the exhibition The Power Of Fantasy in Bozar in Bruxelles at the moment]
However, homemade nuclear exlosions seem to be 'the thing' at the moment: