Why Nuclear Waste Needs to Be Stored for Thousands of Years - An important question for Wyoming

by Wyoming Liberty Group

Why does it take thousands of years—even tens of thousands of years—to store nuclear waste? Better yet, why should we in Wyoming care?

The answers to both questions are important to the Cowboy State, especially now that the legislature's Minerals, Business and Economic Development Committee recently approved a draft bill that would pave the way for Wyoming to temporarily store waste from nuclear fuel. The measure will come up again when the full legislature meets in January.

So, let's try to understand those questions, which is really one question: What's the big deal about storing nuclear waste? Well, as it happens, nuclear waste often must be stored for thousands of years for one simple reason: It's radioactive. It's dangerous. In the lingo of the industry, they say that nuclear waste has long half-lives before it decays to a safer stage.

Hold on a sec; what's a half-life? It's a fancy way of referring to the amount of time it takes for half of a radioactive substance to reduce to the point that only half it remains. Not sure why we need to call it a half-live, but there it is.

What's more important to understand, at least for the moment, is that nuclear waste needs to be contained in isolation so as not to harm human lives, not to mention the environment.

The experts will also tell you that some isotopes, notably plutonium-239, have half-lives of thousands of years. But what's an isotope? In simple terms, it's an atom that, among other things, has the same number of protons but not neutrons. Not sure that helps but perhaps this does: Plutonium-239 is important to understand. It's a radioactive isotope found in nuclear weapons and nuclear reactors. And here's the big deal: It has a half-life of 24,110 years.

Even for us lay people, we know that's a long time.

How, then, do nations dispose of this dangerous stuff that lasts for thousands of years?

Most are looking at what they call deep geological repositories, which is another way of saying they want to bury them way underground.

In the United States, we leave it to the Nuclear Regulatory Agency—the NRC—to figure out how to regulate the storage and disposal of this dangerous material, especially what the federal agency refers to as high-level nuclear waste. That's the bad stuff that comes from nuclear reactors that produce electricity.

But let's dig deeper—no pun intended—to better understand this nuclear waste. It is often referred to as "spent," which is another way of saying that it no longer efficiently produces electricity. This spent fuel is not only radioactive; it's hot, so it needs to be handled with great care. The way the NRC explains it, "Nuclear reactor fuel contains ceramic pellets of uranium 235 inside of metal rods." Uranium 235 is another isotope.

The NRC notes just how dangerous nuclear waste is. "High-level wastes are hazardous because they produce fatal radiation doses during short periods of direct exposure," the federal agency states. "For example, 10 years after removal from a reactor, the surface dose rate for a typical spent fuel assembly exceeds 10,000 rem/hour – far greater than the fatal whole-body dose for humans of about 500 rem received all at once. If isotopes from these high-level wastes get into groundwater or rivers, they may enter food chains."

The idea, if not the details, are clear: The radiation is incredibly lethal.

The NRC explains what we should already know: There are no permanent places in the United States to store high-level nuclear waste. There are lots of reasons for that, including the obvious one: Who wants a radioactive substance in their backyard for thousands of years?

As it is, power plants in the United States store their nuclear waste in what are known as "spent fuel pools." They are kind of what that sounds like—pools. They are comprised of several inches of reinforced concrete walls and steel liners. The pool is usually about 40 feet deep, which is intended to protect against radiation and cool the spent fuel.

Eventually, usually after about five years, the power plants will transfer the spent fuel into what are called "dry casks." These are enclosed in concrete and steel canisters. According to industry estimates, spent nuclear waste can be stored in dry casks for 60 years or so.

But then what? These are all temporary solutions. Which is why we in Wyoming should care. Lawmakers are talking about bringing nuclear waste storage here as a temporary solution. But five years of storage in a pool is not going to cut it. Nor is subsequent storage in dry casks for another 60 years. A permanent solution requires thousands of years, and do we want to hold that radioactive waste for that length of time?