Our nuclear waste disposal problem (not)

We don’t have a technical nuclear waste problem, but we sure have a political problem. To demonstrate, I’ll repeat a few paragraphs from a June 2013 post:

Negligible risks/impacts

dry cask 190x141As someone who works in the area of dry fuel storage, I can tell you that the answer is pretty obvious. The risks of spent fuel storage are utterly negligible, compared to other risks that society routinely faces in general, and in particular, compared to the risks associated with alternative (fossil) power generation options. No credible scenario for a significant release from dry storage casks exists. Even terrorist attacks would have a minimal public health consequence.

Spent fuel pool risks are also quite low, and neither the 5-year cask requirement nor a repository would do much to reduce those (small) risks, since almost all the heat in spent fuel pools is from the fuel younger than 5 years. The theory of spent fuel pool cladding melt or fire (in the extremely unlikely, hypothetical event of pool drainage) is quite dubious in the first place, and it is being addressed at the few plants where it is thought to be a potential concern. Also of note is the fact that the spent fuel pools did NOT release any significant amount of radioactivity at Fukushima.

The fact is that nuclear waste is generated in a miniscule volume and, unlike the wastes from fossil plants and other industries, it has always been safely and fully contained, has never been released into the environment, and has never caused any harm. Further evaluation needed? In my view, the health/environmental impact evaluation for long-term onsite storage of used fuel could be adequately given in one sentence:

“The public health risks and environmental impacts of long term onsite storage of used nuclear fuel are clearly orders of magnitude less than those of the fossil fueled power generation that would otherwise be used in place of nuclear generation.”

It’s clear that shutting the industry down until a repository is built will result in fossil fuels being used for most of the replacement power.  Even if new plant licensing and plant life extensions are suspended, for a long time, the result will eventually be some reduction in nuclear generation, and will result in some increase in fossil generation.

That was written by senior nuclear engineer Jim Hopf who just happens to be a specialist in this area. Nuclear engineers often refer to “waste” as SNF or Spent Nuclear Fuel. It is not actually spent, because in light water reactors less than 1% of the energy has been extracted in a the Jimmy Carter-mandated once-through fuel cycle. The remaining 99% is awaiting favorable politics to be turned into electricity in advanced reactors such as the IFR. So please do not bury the SNF (high value zero-carbon energy) where it will be difficult to retrieve.

Today I read some useful commentary on how the US got into this mess. I was reading the captioned dialog on Our Energy Policy, when I came to comments by an informed observer, Geoffrey Rothwell, who is Principal Economist, Nuclear Energy Agency of the Organization for Economic Cooperation and Development. That’s the NEA of the OECD.  Geoffrey’s comments:

There are plenty of issues to discuss here, and it seems that the discussion is going off on tangents. For example, I believe that Elliot Taubman meant to say that it isn’t Department of Energy’s fault that Yucca Mountain was defunded. There is a general assumption that the US Government is the Administrative Branch and does not include Congress and the Judiciary; hence, the confusion.
Yucca Mountain was on track until the Environmental Protection (?) Agency determined that the design basis of 10,000 years wasn’t long enough to protect future human species from the present generation’s nuclear spent fuel. Thus, it increased the required design basis to 1,000,000 years. While I can imagine 10,000 years into the future (because we can look back at civilized humans over the last 10,000 years), I cannot (and I daresay no one can) design a facility to function as designed for a million years. This slowed down DOE’s license application to such an extent that the NRC was unable to license the design before the Obama-Reid-Pelosi administration took office in January 2009.

What was the implication? The Nuclear Waste Policy Act states in Section 148(d) of the Nuclear Waste Policy Act, PL 97-425, 42 USC 10168: “(d) LICENSING CONDITIONS–Any license issued by the Commission for a monitored retrievable storage facility under this section shall provide that– (1) construction of such facility may not begin until the Commission has issued a license for the construction of a repository under section 115(d); (2) construction of such facility or acceptance of spent nuclear fuel or high-level radioactive waste shall be prohibited during such time as the repository license is revoked by the Commission or construction of the repository ceases;…” Therefore, without a license for a repository, no interim storage facility could be contemplated by the DOE; hence the waste confidence issue appeared. All Congress must do is strike Section 148(d), but that implies that Congress could do something. I don’t believe that Congress will do anything. If one looks at all previous legislation related to nuclear power policy since the Three Mile Island accident, it requires at least 3 sessions of Congress to act and then Congress will only pass such legislation after the elections, i.e., in lame duck sessions (where nuclear power policy cannot be used by non-incumbent candidates as a political weapon). Therefore, while Senate Bill 1240 is a good start, as long as Harry Reid is in power, nothing will happen. Is there a House counterpart? If not, why not? (Because House leadership wants to see Yucca Mountain licensed so as to avoid throwing $10B in Yucca Mountain characterization down a hole, literally).

Why isn’t reprocessing a solution? Unfortunately, when Congress passed the legislation in 1986 limiting characterization of reprocessing sites to Yucca Mountain (because more powerful members of Congress didn’t want the repository anywhere near their backyards (note, however, there is an operating repository in New Mexico at the Waste Isolation Pilot Project, WIPP), the size of Yucca Mountain was limited to 80,000 metric tons of heavy metal (spent uranium fuel). But 80,000 MTHM doesn’t really have anything to do with the carrying capacity of a repository. The carrying capacity of a repository is limited by the ability of the surrounding geology to dissipate heat over the life of the facility. Once the repository is filled, radioactive decay increases the heat in the repository for hundreds of years before cooling begins. Reprocessing reduces the volume and tonnage of the waste, but doesn’t really change the heat load unless the various radio-isotopes can be separated into separate waste streams. This requires new reprocessing technologies and, unfortunately, there is little money to develop these technologies, which require international cooperation and development (every country with spent nuclear fuel is better off with more effectively reprocessing technologies, but no one country can afford to develop them).

On the other hand, the amount of waste that we are discussing is countable. What is uncountable is the equivalent amount of carbon dioxide. Each gigawatt-year of nuclear electricity produces approximately 20 tons of waste (note 20 tons x 40 years x 100 reactors = 80,000 MTHM: Dave, will you check my math?). Given the weight of these 20 tons, the volume is one-third the size of a reactor core: a countable number. One gigawatt-year of coal electricity produces 1,000,000 tons of CO2 (note: 1M tons x 40 years x 100 gigawatts = 4 billion tons of CO2; there are approximately 5 milligrams of CO2 in 12oz can of soda; therefore, we would need to bury 200,000 cans of soda to sequester 1 ton of CO2, i.e., 800 trillion cans of soda; Dave, please check my math). I exaggerate to make the point that Carbon Capture and Storage is a myth and the Waste Isolation Pilot Project is a reality. Finally, climate change is a reality, Hurricane Sandies don’t care whether you believe in climate change: they will flood the New York subway whether you believe in climate change or not. The issue is whether it is easier to manage spent nuclear fuel or CO2. What do you think?

Regarding the quantity of SNF, Geoffrey says it is “countable”. Another adjective is “minuscule”. 

5 thoughts on “Our nuclear waste disposal problem (not)

  1. Engineer-Poet

    Your multiplication of 5 mg * 200k yields only 1 kg, not 1 ton, and my search shows a soda contains closer to 2 g of CO2 anyway.

    But that’s just a nit, for the editor to use in factual cleanup.

    Reply
    1. Steve Darden Post author

      Thanks for the audit – as you can see did not check his math. It’s a challenge to characterize the volume of CO2 produced by coal generation. I’m not sure that trillions of soda cans is more understandable than millions of tons.

      Reply
  2. John Tauxe, PhD, PE

    Yes, it looks like “Dave” did not check Geoffrey Rothwell’s math, as requested. It’s not the editor’s problem, as it is in a quote. But Rothwell seems not to be a sticker for accuracy. For one (perhaps another nit), WIPP is the Waste Isolation Pilot Plant, not Project. More significantly, it was not the decision of EPA to increase the period of performance from 10,000 yr to 1 million years. That was a decision by the Dept. of Justice, who noticed, correctly, that the National Academies had advised EPA to evaluate dose impacts out to their peak values. DOJ ordered EPA to rewrite their regulations accordingly, and EPA interpreted that as requiring 1 million years of analysis (which may or may not capture the peak dose). Rothwell also repeats the false claim that reprocessing will reduce the volume of waste. This is only true in the narrow interpretation that it could decrease the volume of High-Level Waste (HLW), ignoring the much larger (more voluminous) problem of long-lived Low-Level Waste (LLW) that is also a product of reprocessing. If we reprocess, what is to be done with the large amounts of technetium-99 and iodine-129 (just to name a couple of the worst actors) that are now liberated from the contained fuel? We have no excellent technologies for disposing of these radionuclides that will outlive the HLW (I-129 has a half-life of over 1.2 million years).

    Details aside, it is true that the problem of radioactive waste is miniscule in terms of volume and risk when compared to the effects of fossil fuels on public health and the planet’s climate. But if you’re going to argue for it (and I do) then you should not make statements that contain such casual errors and misrepresentations. Nuclear power can be argued to be the best environmentally-responsible alternative without resorting to misleading rhetoric.

    Reply
  3. Steve Darden Post author

    John, thanks for the checks and clarifications. Do you agree that burning LWR SNF in fast reactors (e.g., IFR) reduces the minuscule waste volume to a very small volume, and eliminates all the long-lived isotopes? It is hard to visualize a million tons of CO2, but it is easy for me to visualize that the IFR residual waste from my lifetime of all primary energy production is one 12-oz soda can.

    Reply

What do you think? (first time comments are moderated)

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s