At about 8 p.m. Wednesday, a worker at FirstEnergy’s Davis-Besse reactor noticed a small leak during a walkdown of the reactor coolant system.The unit east of Toledo, Ohio, was offline for scheduled maintenance and refueling, and a report filed with the Nuclear Regulatory Commission said RCS pressure and temperature were normal. The pinhole leak had a reported flow of 0.1 gallons per minute. The report gave the following technical description of the condition: “A pressure boundary leak was identified on the Reactor Coolant Pump (RCP) 1-2 1st seal cavity vent line upstream weld of 3/4 inch small bore pipe socketweld at a 90 degree elbow between the RCP pump and valve RC-407 (1st Seal Cavity Vent Isolation).”A FirstEnergy spokeswoman told the Cleveland Plain Dealer that the coolant was cleaned up, and that no radioactive material was released into the atmosphere.FirstEnergy Nuclear Operating Company operates Davis-Besse, which uses a 913 megawatt Babcock and Wilcox pressurized water reactor first licensed in 1977, according to the NRC.