RADIOACTIVITY.EU.COM

icon THE PHENOMENON

THE PHENOMENON

icon IN DAILY LIFE

IN DAILY LIFE

icon QUESTION OF DOSES

QUESTION OF DOSES

icon AT THE DOCTOR’S

AT THE DOCTOR’S

icon At the laboratory

At the laboratory

icon At the museum

At the museum

icon NUCLEAR ENERGY

NUCLEAR ENERGY

icon RADIOACTIVE WASTE

RADIOACTIVE WASTE

The aim of this web site is to explain radioactivity and its applications to the general public.

In a reactor or an atomic bomb, the criticality factor k is, the average number of secondary neutrons able to trigger secondary fissions. The value of k determines whether the chain reaction takes an explosive turn (k greater than 1) or not (k less than 1). Criticality should be kept equal to 1 in a reactor. Criticality excursions over this value are permissible if they are brief and do not exceed a few per thousand. The difference k-1 is known as reactivity.

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