>All of this was necessary, and they did all of it, no matter the cost.
From Wikipedia:
The official contaminated zones became stage to a massive clean-up effort lasting seven months.[71]:177–183 The official reason for such early (and dangerous) decontamination efforts, rather than allowing time for natural decay, was that the land must be re-peopled and brought back into cultivation. ... Yet this land was of marginal agricultural value. According to historian David Marples, the administration had a psychological purpose for the clean-up: they wished to forestall panic regarding nuclear energy, and even to restart the Chernobyl power station.
From Wikipedia:
The official contaminated zones became stage to a massive clean-up effort lasting seven months.[71]:177–183 The official reason for such early (and dangerous) decontamination efforts, rather than allowing time for natural decay, was that the land must be re-peopled and brought back into cultivation. ... Yet this land was of marginal agricultural value. According to historian David Marples, the administration had a psychological purpose for the clean-up: they wished to forestall panic regarding nuclear energy, and even to restart the Chernobyl power station.