Documents show that the Vermont Yankee nuclear plant's operators knew there were underground pipes at the plant--pipes officials later said didn't exist.

A sworn affidavit from Vermont Yankee chief engineer Norm Rademacher refers to a report from November of 2007 on the plant's buried piping and tank inspection program. Rademacher says what was looked at then matches what was later asked about - whether there were pipes under the plant that could carry radioactive tritium.

Vermont Yankee is currently investigating a recent leak of tritium at the plant.

A big issue in the recent debate over the plant has been whether Vermont Yankee intentionally misled state officials about the pipes.