So long as it can be compressed and heated. Breach containment, and both the pressure and the heat dissipate, thus quenching the reaction.
A Fusion reactor cannot blow. On the other hand, the superconducting coils that make it work CAN blow, and unleash a huge amount of energy when they do, but it won't be Fusion. It will be stored magnetic energy.
Still a pretty good "bang", though.
dear diogenes,
Please remember:
A thermonuclear bomb is a fission/fusion reaction, with no real containment vessel.