Meltdown: Days 3-4

You are really a collection of parts: organs and bones, tendons and teeth.

Hold my hand, and the atoms on the surface of your skin interact with the atoms on mine. If you’re unlucky enough to do it on a cold, dry day, loose electrons might leap from my hand to yours, giving you a static electric shock.

Long after you die, your atoms will still be here as part of the soil, rock, water, and air—perhaps even another animal. And yet atoms can be affected by things on their own miniature scale, things so small that they are invisible to us.
It’s our atoms that make us vulnerable to radiation.

Put simply, radiation is energy. It travels through our world as particles or waves, and it is everywhere. Solar radiation warms our planet and feeds the plants we need to survive. Radio waves, another form of radiation, carry information from your Wi-Fi router to your computer and from cell phones to the nearest cell tower. Visible light is also radiation.

Each of our atoms holds protons and neutrons at its center in a super-dense mass called the nucleus. Electrons hover around the nucleus in a cloud. This tiny galaxy forms its own balance between the positive charge of the protons in its nucleus and the negative charge of the electrons that surround them.

But if a radioactive particle or wave has enough energy, it can knock electrons out of an atom altogether, creating an ion.

If they’re released during a nuclear accident, the same neutrons that ping around inside the nuclear reactor breaking apart uranium atoms can careen through a worker’s body.

The course of radiation sickness, also called acute radiation syndrome, varies widely depending on what kind of radiation was absorbed and where in the body it causes the most damage.

In high enough doses, radiation sickness almost always causes nausea, headaches, and a general feeling of illness that can last anywhere from a few hours to two days. After that, the symptoms disappear for a time. With milder poisoning, this period of normalcy can last up to two weeks; in severe cases, it ends in as little as five days.

Then the real impact of the radiation strikes, with grisly symptoms that range from hair loss and extreme fatigue to the destruction of bone marrow and internal bleeding.

A person exposed to 1 sievert (Sv) of radiation suffers light radiation poisoning and has a 90 percent chance of survival. Around 4 Sv, the odds of survival drop to 50 percent. At 10 Sv, exposure is always fatal.
It sounds terrifying, but the odds of the average person encountering that kind of radiation are minuscule.

The heart of a nuclear reactor seethes with deadly radioactivity.

In the 1950s and ’60s, the U.S. Air Force ran a series of experiments in a secluded stretch of woods 50 miles from Atlanta, Georgia. The Georgia Nuclear Aircraft Laboratory ran a 10-million-watt nuclear reactor completely unshielded. Everything within 1,000 feet of the reactor died.

Desperate to replace the cooling water in the reactor, Yoshida decided it was time to try his last resort: seawater.

Normally, nuclear reactors use purified water, which runs through a closed system to ensure that none of the water from the reactor can get out—and that no impurities can get in. That’s because minerals in unpurified water can attach to the metal surfaces and fuel rods in the reactor core, interfering with the carefully maintained reaction occurring inside.

The salt in seawater also corrodes metal and destroys electrical connectors.

Workers scrambled to get the pumping system back online, patching the hoses that could be salvaged and cobbling together any new hoses they could find to replace the ones that could not.

But in the meantime, Prime Minister Naoto Kan had balked at the idea.

Not fully versed on the workings of the reactor, he was concerned that the seawater could lead to another explosion.

But Yoshida worried that the odds of getting their ad hoc pumping system going again would be slim if they stopped.

Yoshida was not only lying to his bosses at TEPCO, he was also defying an order from the prime minister of Japan.

Because they had battery power, water injection had been a far easier task for the operators of unit 3 than it was for those of unit 1, but they were still improvising.

The HPCI was meant to be used in the case of a sudden loss of water, like when a pipe ruptures.

Both the Fukushima Daiichi and Fukushima Daini plants were out of commission following the tsunami, creating a shortage in the electricity supply.

Necessities of all kinds were also in short supply near the stricken coast.

With supply routes on land severely damaged, the quickest route for bringing humanitarian supplies such as food, water, and first-aid equipment to devastated coastal towns was by sea, so the aircraft carrier headed for Japan, where it would serve as a fueling and supply station for disaster relief operations.

Seventeen crew members who had ridden in the helicopters had to be decontaminated, scrubbed from head to foot to remove any radioactive particles. Their clothes were sealed in plastic bags for disposal.

When an atom of uranium splits, the pieces aren’t just smaller than the original atoms; they also have a different number of protons in their nuclei. That means that the new atoms are no longer uranium—they have become different elements. And they aren’t necessarily stable.

Atoms of the same element that have different numbers of neutrons are called isotopes of each other. If the number of neutrons creates an imbalance in the atom’s nucleus, that isotope is radioactive. Over time, it will shed neutrons, protons, or both until it reaches a more stable form.

But radioactive isotopes—the broken bits themselves—can travel far from their source. Carried in smoke and steam, they drift on the wind or in the water. Eventually, they decay, emitting radiation in their new location.

Nuclear operators go through rigorous control measures to make sure they don’t carry radioactive dust out of the plant at the end of a workday.

Anyone working in an area where radioactive materials may have been is required to wear a radiation suit—usually coveralls that are fastened tightly at the ankles and wrists, gloves, special socks, boots, goggles, and a breathing mask with a filter.

And the workers had to eat and drink. To do that, they had to pull off their face masks. It was a major breach of safety protocol that risked the workers swallowing radioactive dust with their food or inhaling it while they ate. But it was that or starve.

To stay within the legal limit, the workers needed to leave the plant if they reached that dose, and they were desperately needed where they were. So on March 14, Japan’s Ministry of Health, Labor, and Welfare raised the legal limit for annual exposure in an emergency to 250 mSv.

Nuclear fission creates several isotopes that are close enough to minerals the body needs to be dangerous. Strontium 90 is chemically similar to calcium, and so it is absorbed by the body and deposited in the bones. Once there, it can remain for decades, releasing radiation into the bones and bone marrow.

But in the event of a nuclear accident, people who may be exposed to iodine 131 can take potassium iodide tablets, which provide enough non-radioactive iodine 127 to saturate the thyroid. The body, no longer needing iodine, will simply let any radioactive iodine it may encounter pass through harmlessly.

The Comprehensive Nuclear-Test-Ban Treaty Organization, which monitors releases of radioactive isotopes around the world, was also watching the unfolding disaster on the eastern coast of Japan.

The group created a weather-based map that showed the likely path of the radioactive plume from Fukushima swirling across the North Pacific and sweeping onto the west coast of the United States.

Of the three reactors that had been operating when the tsunami hit, unit 2 was the only one that was still intact. It had been functioning pretty well, but around noon on March 14, that had begun to change.

With no water coming in, the number 2 reactor was going to melt. All fuel was going to really override pressure in the containment vessel and escape outside.