Take out the nuclear fuel pin when cooling ends to some degree.
It puts in the pool for cooling, about four years are spent, and it cools completely.
A completely cold nuclear fuel is hardened with concrete and it annuls it.
Because the nuclear reactor cannot be restored, it covers with concrete and it annuls it.
It is considerably different from the case with Chernobyl.
It resembles this case closely.
Three Mile Island accident - Wikipedia, the free encyclopedia