Reinforced concrete wall under hydrogen detonation
The structural integrity of a reinforced concrete wall in the BWR reactor building under hydrogen detonation conditions
has been analysed. Of particular interest is whether the containment integrity can be jeopardised by an
external hydrogen detonation. The load carrying capacity of a reinforced concrete wall was studied. The detonation
pressure loads were estimated with computerised hand calculations assuming a direct initiation of detonation
and applying the strong explosion theory. The results can be considered as rough and conservative estimates for
the first shock pressure impact induced by a reflecting detonation wave.
Structural integrity may be endangered due to slow pressurisation or dynamic impulse loads associated with local
detonations. The static pressure following the passage of a shock front may be relatively high, thus this static or
slowly decreasing pressure after a detonation may damage the structure severely. The mitigating effects of the
opening of a door on pressure history and structural response were also studied. The non-linear behaviour of the
wall was studied under detonations corresponding a detonable hydrogen mass of 0.5 kg and 1.428 kg.
Non-linear finite element analyses of the reinforced concrete structure were carried out by the ABAQUS/Explicit
program. The reinforcement and its non-linear material behaviour and the tensile cracking of concrete were modelled.
Reinforcement was defined as layers of uniformly spaced reinforcing bars in shell elements. In these studies
the surrounding structures of the non-linearly modelled reinforced concrete wall were modelled using idealised
boundary conditions. Especially concrete cracking and yielding of the reinforcement was monitored during
the numerical simulation.