SBT configuration of 'default' JDK

Our usage of IDEA is operating on Scala code with an SBT build file. Most of the developers I support are extremely reluctant to use any IDE at all, so I'm doing my best to make everything 'trivial' to use.

One problem I've had recently is that, on the 'first' invocation of 'idea', my code will not compile until a JDK is explicitly created in the Project Structure setting. It would be much better if that could be automatically done inside the SBT file (and it would make it more difficult for us to get into a situation where we are not all exactly aligned).

Is there a way to do that? I tried setting JDK_HOME, but that didn't seem to do it.