Editing Nuclear reactor (section)

===Heat generation===
The reactor core generates heat in a number of ways:
* The [[kinetic energy]] of fission products is converted to [[thermal energy]] when these nuclei collide with nearby atoms.
* The reactor absorbs some of the [[gamma rays]] produced during fission and converts their energy into heat.
* Heat is produced by the [[radioactive decay]] of fission products and materials that have been activated by [[neutron absorption]]. This decay heat source will remain for some time even after the reactor is shut down.

A kilogram of [[uranium-235]] (U-235) converted via nuclear processes releases approximately three million times more energy than a kilogram of coal burned conventionally (7.2&nbsp;×&nbsp;10<sup>13</sup> [[joules]] per kilogram of uranium-235 versus 2.4&nbsp;×&nbsp;10<sup>7</sup> joules per kilogram of coal).<ref>{{cite web|url=http://bioenergy.ornl.gov/papers/misc/energy_conv.html |title=Bioenergy Conversion Factors |publisher=Bioenergy.ornl.gov |access-date=18 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110927181836/http://bioenergy.ornl.gov/papers/misc/energy_conv.html |archive-date=27 September 2011 }}</ref><ref>{{cite book |url=https://archive.org/details/nuclearweaponswh0000bern/page/312 |title=Nuclear Weapons: What You Need to Know |author=Bernstein, Jeremy |year=2008 |page=[https://archive.org/details/nuclearweaponswh0000bern/page/312 312] |isbn=978-0-521-88408-2 |publisher=[[Cambridge University Press]] |access-date=17 March 2011 }}</ref>{{Original research inline|date=March 2012}}<!--see this is more than [[WP:CALC]]. See [[Talk:Nuclear reactor#Energy efficiency?]]-->

The fission of one kilogram of [[uranium-235]] releases about 19 billion [[kilocalories]], so the energy released by 1&nbsp;kg of uranium-235 corresponds to that released by burning 2.7 million kg of coal.