Common
Iodine pit
Problem in nuclear reactor start-up
Iodine pit
The iodine pit, also called the iodine hole or xenon pit, is a temporary disabling of a nuclear reactor due to the buildup of short-lived neutron poisons in the reactor core. The main isotope responsible is 135Xe, mainly produced by beta decay of 135I. 135I is a weak neutron absorber, while 135Xe is the strongest known neutron absorber. When 135Xe builds up in the fuel rods of a reactor, it significantly lowers their reactivity, by absorbing a significant amount of the neutrons that provide the nuclear reaction. The presence of 135I and 135Xe in the reactor is one of the main reasons for its power fluctuations in reaction to change of control rod positions. The buildup of fission products acting as neutron absorbers is called fission-product poisoning (also reactor poisoning), most importantly 135Xe poisoning; stable absorbers such as 149Sm are likewise treated as fission-product poisons.
Open boosters, collect cards and trade them. Free to play.
Play for free