The neutron moderator is light demineralized water, which is also used as a neutron reflector, as biological shielding, and as a coolant.
42.
Neutrons can be slowed to thermal energies through collisions with a neutron moderator material, the easiest to use being the hydrogen atoms found in water.
43.
Note also that, under these circumstances, neutron moderators won't be thermally significant, as heat generation will increasingly be from byproduct decay.
44.
The Atomic Energy of Canada Limited ( AECL ) design of power reactor requires large quantities of heavy water to act as a neutron moderator and coolant.
45.
At that time the natural uranium had a concentration of about 3 % 235 U, and could have gone critical with natural water as neutron moderator.
46.
In the advanced gas-cooled reactor, a British design, the core is made of a graphite neutron moderator where the fuel assemblies are located.
47.
Ruth used the hydrogen isotope protium ( 1 H ) and Ray used the hydrogen isotope deuterium ( 2 H or 2 D ) as neutron moderators.
48.
Such a reactor needs no neutron moderator, but must use fuel that is relatively rich in fissile material when compared to that required for a thermal reactor.
49.
It uses CANDU reactor technology from AECL, using heavy water produced at Drobeta-Turnu Severin as its neutron moderator and water from the Danube for cooling.
50.
Had he not done so, they might have concluded, as the German nuclear weapon project did, that graphite was unsuitable for use as a neutron moderator.
