Such exercises in ethics or logic are ,in reality,tools designed to destroy compassion and Western Civilization.They most often invoke false dilemas and assume worst cases.Supplies for six persons for a fixed period coulkd be stretched for a seventh with only slight increase in radiation risk because the half-life decay curve isn't going to be that much different.And a human body in storage?What ,you have refrigeration?Oh,a hermetically sealed container?Amazing!Otherwise the decaying body will cause illness of the physical as well as pschological variety.Of course ,by "offing" one of your group the rest have become amoral killers,unable to trust each other.Not a good survival situation.