I've been writing about the structure reforms required to 'fix' our broad public pension problems. In addition to those changes, we need Congress to revise pension management regulatory rules to make more options possible. Unfortunately, it does not appear to be happening at the moment - there is political division and the 'solutions' being proposed don't really address the problems.
See this article for the most current state of affairs on this topic at the Congressional level.
These plans' issues are not going to be fixed by low-interest loans. Younger workers at employers participating in these plans deserve to be able to accrue retirement benefits that will be there for them when they retire. Older workers and retirees deserve some certainty and answers as well. And this requires that Congress be willing to find a bipartisan solution.