I'm using BiggerReactors (0.6.0-beta.10.4) in Project Architect 2 - 4.3 release and having built a 7x7 reactor I've got issues with waste. I think this is a known issue but I can't see it reported.

Steps to reproduce:

• Setup reactor 7x7 - 5 cores - diamond block moderator (size probably doesn't matter)
• Add reactor access ports x 2
• Put hopper and chest and set port 1 to input (also tried with RS exporter) - fill with uranium
• Put pipez and chest and set port 2 to output - waste, configure pipe end to chest
• On reactor terminal select auto eject waste
• Online the reactor - note after a period of time that waste appears in the input hopper. Note that manually ejecting waste can have the same affect,