Remove all grammar issues from the given sentence
It is because the heat efficiency in current nuclear plants is only 1%, which means 99% of the energy generated by nuclear plants is wasted4, but Scientists have already found out ways to increase the heat efficiency.
It is because the heat efficiency in current nuclear plants is only 1%, which means 99% of the energy generated by nuclear plants is wasted4, but Scientists have already found ways to increase the heat efficiency.