Recently it was expressed to explain the procedures of shutting down a radiation involved emergency. This of course can included a vast majority of incidents ranging from, medical supplies, nuclear shipping containers driving down the road, nuclear ordinances used by the military forces, or even to an actual reactor creating energy for today’s consumer. Within the Fire Service we are rendered tasked with the mitigation of emergency situations that pose a threat to life or property. This can and does include radioactive materials incidents such as the most notable one at Fukushima Daiichi nuclear plant in Japan.
The question posed by readers describes, how do you contain such an incident? What is the time frame spent to gain control? How do firefighters know what to do? The simple answer to all those questions is, we do not know. There are few events in history that are one in the same, no vehicle accident at the same intersection results in the same injuries and the same outcome. This being true in at the Fukushima nuclear plant comparing to the Three Mile Island disaster. Of course similar in how the incident occurs and spreads, containment can be quite different.
Simply put, in regards to a nuclear accident on the highway involving shipping containers it is much different than a nuclear plant that has been compromised. As a small highway accident will in most cases only effect a few miles if any, a nuclear plant accident has a infinite amount of damage it can unfold.
In Japans situation, they have a Reactor with a possible compromise to the core. With the Tsunami that occurred and earthquakes their cooling system has failed. To keep things simple, Imagine following a volt of electricity back through the wall socket, all the way through miles of power lines to the nuclear reactor that generated it. You'd encounter the generator that produces the spark and the turbine that turns it. Next, you'd find the jet of steam that turns the turbine and finally the radioactive uranium bundle that heats water into steam. Welcome to the nuclear reactor core. The water in the reactor also serves as a coolant for the radioactive material, preventing it from overheating and melting down. This is dangerous because of the way the reactors are set up. The uranium/plutonium rods are supposed to be submerged in water because the heat from the nuclear reaction is supposed to heat up the water and make steam to move the turbines to create electricity. In the case there is very little to no water for the uranium/plutonium rods to be submerged into so they have no way to be cooled down. The power plant can control the reaction by adding "control rods" which can slow down or stop the reaction completely. When the earthquake hit, the control rods were put into the reactor, stopping the reaction but the uranium/plutonium rods were still hot (kind of like turning off an iron; it's not working but it's still hot for awhile). This heat is creating huge amounts of pressure inside the already pressurized chamber where the radioactive material is being kept.
The response to a incident like this are devastating as you might imagine, though where there is a will there is always a way, currently the plan is to use in conjunction the control rods and copious amounts of water to cool the uranium rods and thus bring down the temperatures and emissions of radiation to the area. With fractures around the core, it is not allowing for water to submerge the rods sufficiently.
From the fire service standpoint, I can honestly say this is a perfect storm, you have a hazardous condition that can have deadly after effects if you get close enough, but at the same time the damage will continue to mount until the situation is resolved or resolves itself. In summary, the response to this incident is what they are doing, trying to minimize loss of life while at the same time keeping an adequate barrier between the reactor and human life.