Classifications of nuclear waste need a shorter half-life

A funny thing happened on the way to our high-level nuclear waste dump. Most of America’s high-level nuclear waste is no longer high-level.

This is a good thing.

Unfortunately, on paper it’s still called high level waste. On legal paper, no less.

Various processes have changed the nature of this waste over the last 50 years, especially in the Hanford waste tanks. But human laws consider what it was a long time ago, not what it is now.

So, what happens when human law collides with natural law?

First, it always ends up costing us a lot of money. Second, we always take too long to change the human law, which is why it ends up costing us a lot of money.

Nuclear waste comes in four colors: commercial spent nuclear fuel (SNF), high-level nuclear waste (HLW) and transuranic waste (TRU) — both from making weapons — and low-level radioactive waste (LLW) from many things like the mining, medical and energy industries. A minor amount of other radioactive wastes are sprinkled among these categories.

SNF is the hottest waste, primarily from two isotopes, Cs-137 and Sr-90, both with approximately 30-year half-lives, making the waste high-level for much less than 200 years.

Similarly for HLW — it’s the Cs-137 and Sr-90 that make it hot, although not so much as SNF. LLW is not very hot at all.

TRU waste spans the gamut from low-level to high-level, and is primarily determined by the amount of plutonium, while the level of hotness is again determined by the amount of Cs-137 and Sr-90.

The details get a little complicated, but HLW refers to waste with high levels of radioactivity that was generated from reprocessing nuclear fuel from weapons reactors to make atomic, and then nuclear, weapons.

HLW is defense waste, and much of it is nasty, gooey, watery sludge with the consistency of peanut butter or week-old pudding. Tricky to handle.

This is very different from commercial spent nuclear fuel (SNF) that has even higher levels of radioactivity but comes from commercial power reactors and is dry and solid. Easy to handle.

TRU waste is a combination of debris, cements and sludge, a real mish-mash of materials that just has enough plutonium in it to call it TRU, but not enough Cs-137 and Sr-90 in it to call it HLW.

TRU and HLW tank waste are both generated in the reprocessing of spent fuel from a weapons reactor (not a commercial power reactor), but are differentiated by when in that process they were generated. HLW is generated in the early steps of the process that removes the fission products (the pieces left over when the uranium or plutonium nucleus splits, or fissions), particularly the Cs-137 and Sr-90.

TRU is generated in the following steps that separate the Pu and U for weapons, and has much less Cs-137 and Sr-90, although the amount varies.

The HLW and the TRU sit at various Department of Energy sites around the country in liquid, sludge and solid forms, but most of the HLW is in those famous tanks at the Hanford site that hold 57 million gallons of it, recently made more famous by a few leaks. Not any threat to human health and the environment, but enough to get everyone upset.

The strange thing is, thirty years ago we removed much of the Cs-137 and Sr-90 from these HLW waste tanks, and the rest has been through one or two half-lives, so there’s not enough Cs-137 and Sr-90 to make it HLW anymore, at least in reality, scientifically.

Instead, most of it is now TRU waste with activities well below 1 Ci/liter, much easier to dispose of correctly. But it’s still legally HLW.

What we have here is a classic bureaucratic knot of conflicting definitions that we need to fix in order to stop spending money just treading water, and to move forward with a resolution to our halted nuclear waste disposal program that we can afford and that is as safe as the old one.

In 2012, the President Obama’s Blue Ribbon Commission, which included the last Secretary of Energy, Dr. Ernie Moniz, already laid out a plan to correct this mess (BRC Report to President Obama). First, put SNF in interim storage for decades. This allows it to be separated from the defense HLW, with which it has been foolishly lumped together for the last 50 years.

Next, we have to call the waste what it is.

I know that requires a hefty bureaucratic lift since many groups are ideologically wedded to the past and we are a litigious country, if nothing else. But, come on, please don’t say we can’t even define something anymore by what it actually is.

The multitude of laws and orders developed over the last 50 years have given us all the language and solutions we need, from the Ronald W. Reagan National Defense Authorization Act to the Nuclear Waste Policy Act, from wording by the House Armed Services Committee to the NRC’s 10 CFR Part 61, to various DOE Orders. We just have to follow them and call things what they are.

When we understand what the waste is, and we do, then we can handle it, treat it, prepare it and dispose of it correctly.

Changing laws and agreements is very difficult these days, but is still a lot easier and cheaper than ignoring reality and treating HLW that is no longer high-level. The difference is about $200 billion.

This is more than an academic exercise since we’re, you know, broke.