To calculation of samarium poisoning in a starting duty after continuous stop of poisoned reactor

In the literature dedicated to physics of transients and basic physics of exploitation of nuclear reactors the starting duty after continuous stop of a poisoned reactor was not practically considered. In operational practice there is the rather a slow passing process (from several days up to tens day) and insignificance of effects of change of fuel scarifying (less than prompt criticality). It is necessary to note, that the radiation annealing of samarium is equivalent to input of a positive reactivity, and the increase of density of a neutron flux increases the role of effects of a poisoning with samarium and they can become predominant. These circumstances demand from the point of view of nuclear safety, more stringent consideration of behavior of samarium in these transient regimes. The paper reviews the mathematical formulation of the problem of poisoning a reactor with ¹⁴⁹Sm