Thirteen years after the devastating explosion at the Chernobyl nuclear power plant in Ukraine, wrangling continues on how to close down the undamaged reactors on the site, and replace the electricity they supply. Five years ago, the Group of Seven industrial nations agreed to finance alternative energy sources, in return for a promise to close chernobyl . The $1.7 bn deal was to include completion of two half-built nuclear reactors, provided that was proved to be the least cost solution. But nothing has been done.