Lenitive; tending to alleviate.

noun. That which mitigates or tends to moderate or alleviate.

adjective. Tending to mitigate; alleviating.

adjective. Serving to mitigate.

adjective. moderating pain or sorrow by making it easier to bear

""Our initial guidance on these strategies focused on the mitigative actions themselves, but we also need to consider things such as operator training and maintaining the related equipment," said Eric Leeds, director of the NRC's Office of Nuclear Reactor Regulation."

moderating  

alleviating