Safety hypothetical measure

Processing of the drum incident thus led to similar principles being applied to reactor vessels and reinforced the procedures to be applied in the case of leaks from the mam vessel by supplementary measures These measures are contained m procedure U4 "Steps taken to limit the consequences of a hypothetical leak from the safety tank as a result of a leak from the reactor mam vessel"... 

In the course of time, e.g. following the TMI-accident, and further development of safety engineering, additional measures to control hypothetical system failures and combination of failures or to mitigate the consequences of such beyond DBAs were introduced as accident management measures. These primarily addressed the use of existing equipment in beyond DBA scenarios. 

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