Dangerous Flaw Threatens to Close Nation’s Nuclear Fleet – By Roger Witherspoon
Byron Nuclear Power Plant
After four years of increasingly tense internal discussion, seven Nuclear Regulatory Commission engineers have formally petitioned the governing Commissioners to either order the nation’s nuclear power plants to immediately correct a design flaw governing their reactor cooling systems or order them all to shut down.
The flaw is in the original design of the electrical system, and has escaped notice for decades. According to the engineers’ petition, as well as a series of staff analyses on file at the NRC, the design flaw occurs in what is called a “single phase” condition in which little or no electricity is entering the plant to operate its backup cooling systems in the event of a blackout or other event cutting off power from the grid. The result is that the motors of backup generators are underpowered and this can cause their motors to burn out. When that happens, there is no way to keep the reactor core cool.
The seven members of the Electrical Engineering Branch in the Office of Nuclear Reactor Regulation, led by Acting Chief Roy K. Mathew, stated in the petition that “the staff determined that all nuclear facilities are susceptible to this design vulnerability except one plant, and recommended that the NRC take prompt regulatory action.”
As a result, the petition states, if the plants are not ordered to immediately redesign their electrical systems then the Commissioners should “issue Orders to immediately shutdown the operating nuclear power plants since the licensees are operating their facilities without addressing the significant design deficiency…and with inoperable electric power systems….”
The situation evolved from an unplanned shutdown in January 30, 2012 in Unit 2 of the Byron Station Nuclear Power Plant in Illinois. At the time, it was thought that the shutdowns resulted from a string of unfortunate coincidences. But further examination by the NRC’s electrical engineering branch found something more alarming. Read more