http://www.whatisnuclear.com/articles/nucenergy.html http://www.whatisnuclear.com/articles/nucenergy.html measured by energy density http://www.whatisnuclear.com/articles/nucenergy.html http://www.whatisnuclear.com/articles/nucenergy.html http://www.whatisnuclear.com/articles/nucenergy.html Source of table http://www.whatisnuclear.com/articles/nucenergy.html http://www.whatisnuclear.com/articles/nucenergy.html Source of table