Schema di reattore nucleare tipo "pebble bed".
<a href="//commons.wikimedia.org/w/index.php?title=User:Picoterawatt&amp;action=edit&amp;redlink=1" class="new" title="User:Picoterawatt (page does not exist)">Picoterawatt</a>
4 January 2010 (upload date)
<span class="int-own-work" lang="en">Own work</span>