SPOKANE, Wash. -

A federal judge has rejected the U.S. Department of Energy's motion to dismiss a lawsuit filed by Washington state over worker safety issues on the Hanford Nuclear Reservation.
   
U.S. District Court Judge Thomas Rice ruled Thursday that state Attorney General Bob Ferguson has the authority to bring the lawsuit.
   
The judge rejected the Energy Department's argument that the federal agency was not endangering a sufficient number of Washingtonians to allow the state to sue.
   
Ferguson filed the lawsuit last fall against Energy and contractor Washington River Protection Solutions. The lawsuit contends hazardous tank vapors pose a serious risk to workers at Hanford.
   
Trial is set for next May 22.
   
Hanford for decades made plutonium for nuclear weapons and now is engaged in cleaning up a massive quantity of radioactive waste.