Minimal endogenous mortality

The minimum endogenous mortality ( MEM ) is a term from the risk analysis for technical, safety-relevant systems, such as power plants or railway systems (see probabilistic safety analysis ). MEM is a measure of the accepted (inevitable) risk of death from the technology in question.

It is described in the CENELEC standard EN 50126 and specified as 0.0002 deaths per person and year . Statistically, this is the mortality (risk of death) of a European adolescent.

MEM is mainly used as an absolute risk threshold for the approval of complete systems. New systems must not have a higher risk than the existing ones (referred to in the standards as the GAMAB principle, from the French Globalement Au Moins Aussi Bon ). Since everyone is exposed to “many” (standardized: 20) technical systems at the same time, a threshold of 1/20 MEM = 0.00001 deaths / year is set for each system. This value must not be exceeded by planned innovations. On the contrary, new technologies must generally be more secure than old ones, as technical progress makes this possible ( ALARP principle, from English as low as reasonably practicable ).

MEM has limitations:

• It is not certain that a system that meets the MEM criterion also meets the ESO standard.
• Since MEM sets a fixed risk criterion , it is absolute and does not adapt to society. The perception of whether something is too risky depends on numerous factors, for example whether there is an alternative or whether there have recently been major accidents that raise public awareness.