Flaws in pipe seams in the cooling system of Chernobyl’s only functioning nuclear reactor have caused a new delay in the restart of the power plant. Taken offline July 21st for maintenance that was supposed to last 70 days, Reactor Number 3 will not be turned back on until early next year. Officials announced an initial delay last month because repair workers unexpectedly found it was necessary to replace more than a hundred of the reactor’s fuel channels, a network of pipes that move fuel through the reactor. The pipes showed signs of wear and tear.