CFCs and Nuclear Power

Date: 25 Mar, 2011
Posted by: admin
In: life & family

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Apparently, according to a FoaF’s post today on FB nuclear power produces CFCs (Chloro-Fluoro-Carbons poster child of global warming terror in the 90s). Here’s a little research I did on that claim. Note this is not properly written up, as yet, but simply a record of sources found and my notes along the way.

Does nuclear power production produce CFCs [aka Freon]?

There is much in the news recently about nuclear power and I’m conscious this post could appear to be bandwagon-ing. I’m not attacking nuclear power generation, simply trying to educate myself about a facet of it that I haven’t considered before, that in the enrichment of uranium substantial amounts of CFC might be produced at a significant cost to the environment. Is this true, read on and perhaps we’ll find out …

Or, if this looks like one huge pile of text to get through then skip to the Summary or TL;DR at the end, thanks.

Initial sources

Safety of old and new nuclear reactors – Lochbaum

David Lochbaum on May 8, 2001  gave a UCS testimony on nuclear power before the “Clean Air, Wetlands, Private Property, and Nuclear Safety Subcommittee” of the United States Senate Committee on Environment and Public Works. This testimony was titled “Safety of old and new nuclear reactors” (document linked on UCSUSA.org website).

Nuclear Power Is Not the Answer – Caldicott

The original details are from “Nuclear Power Is Not the Answer to Global Warming Or Anything Else” by Helen Caldicott (buy on Amazon US, UK; Google Books) who discusses the above mentioned testimony (or it’s content at least) with respect to CFCs on pages xiii and 10.

Page xiii (transcribed by me from Google books, links added by me):

Nuclear power is not “clean and green,” as the industry claims, because large amounts of traditional fossil fuels are required to mine and refine uranium needed to run nuclear power reactors, to construct the massive concrete reactor buildings, and to transport and store the toxic radioactive waste created by the nuclear process. Burning of this fossil fuel emits significant quantities of carbon dioxide (CO2) — the primary “greenhouse gas” — into the atmosphere. In addition, large amounts of the now-banned chlorofluorocarbon gas (CFC) are emitted during the enrichment of uranium. CFC gas is not only 10,000 to 20,000 times more efficient as an atmospheric heat trapper (“greenhouse gas”) than CO2, but it is a classic “pollutant” and a potent destroyer of the ozone layer.

Page 10 (transcribed by me from Google books, links added by me):

In 2001, however, the privately owned and operated United States Enrichment Corp. consolidated its operation in Paducah. The Paducah enrichment facility uses the electrical output of two dirty, old 1,000 megawatt [sic] coal-fired plants for its operation, contributing significant carbon dioxide to the atmosphere. It has also recently been revealed by the U.S. Department of Energy that CFC 114 gas — a compound that is a potent global warmer and that destroys the stratospheric ozone layer — leaks unabated from the hundreds of miles of cooling pipes used in the uranium enrichment operation at Paducah, Kentucky, and its sister facility in Ohio.

Does all uranium enrichment evolve/use CFC?

Setting aside other issues my first ports of call for corroborating info on uranium enrichment processes were Wikipedia and the BBC.

Reading between the lines with these sources it seems that CFC must be part of the Gaseous Diffusion process. Wikipedia claims that this accounts for 33% of global production and that it is being phased out. Certainly the BBC link appears to show that everyone who’s anyone is using centrifugal techniques to enrich their uranium nowadays.

This guess lead me via a Google search to the US DOE Environmental Management web pages and in particular back to Paducah.

The operation of the Paducah Gaseous Diffusion Plant has produced a number of contaminated areas, both at the site and beyond its boundaries. Ground water northwest of the site has been found to be contaminated with technetium­99 and the chlorinated solvent trichloroethylene.

Unfortunately it didn’t yield any specifics about use and/or release of CFC 114.

Ah! Freon!

Another source, coolreferat.com, yielded me the realisation that CFC 114 is often called Freon (or Freon 114) and gives good information on specifics of it’s use in uranium enrichment too. Freon used to be widely used in Fridges:

In addition to requiring a large amount of electricity during operation, the compressors in the gas diffusion facilities also generate a great deal of heat that requires dissipation. In U.S. plants this heat is dissipated through the use of ozone depleting chlorofluorocarbons (CFCs) such as the coolant CFC-114 (often referred to simply as Freon of Freon-114). The manufacture, import, and use of CFCs were substantially restricted by the 1987 Montreal Protocol on Substances That Deplete the Ozone Layer […]

In 2002, the Paducah enrichment plant emitted more than 197.3 metric tons of Freon into the air through leaking pipes and other equipment. This single facility accounted for more than 55% of all airborne releases of this ozone depleting CFC from all large users in the entire United States in 2002. Due to the lack of additional manufacturing of Freon since 1995, the U.S. Enrichment Corporation is currently looking for a non-CFC coolant to use. Likely candidates […] would still remain a potential concern in relation to global warming and climate change.

Reviewing the other sources I found that the DOE source about does mentioned Freon with respect to the need to remove it when decommissioning but neither the BBC nor Wikipedia pages mention “Freon” (nor, as I said, “CFC”).

Coolreferat.com also gives information about the other methods of uranium enrichment:

The use of centrifuges also reduces the amount of waste heat generated in compressing the gaseous UF6, and thus reduces the amount of coolants, such as Freon, that would be required.

and

As with gaseous diffusion plants, there is a large amount of heat generated during operation of an aerodynamic separations plant which requires large amounts of coolants such as Freon.

So to summarise this part it seems that – yes most methods of uranium enrichment in use do result in Freon/CFC-114 being released in to the atmosphere.

A note on the Montreal Protocol and HCFCs

From Wikipedia:

Hydrochlorofluorocarbons (HCFCs) Phase-out Management Plan (HPMP)

Under the Montreal Protocol on Substances that Deplete the Ozone Layer, especially Executive Committee (ExCom) 53/37 and ExCom 54/39, Parties to this Protocol agreed to set year 2013 as the time to freeze the consumption and production of HCFCs. They also agreed to start reducing its consumption and production in 2015. The time of freezing and reducing HCFCs is then known as 2013/2015.

The HCFCs are transitional CFCs replacements, […] . In term of Ozone Depleting Potential (ODP), in comparison to CFCs that have ODP 0.6 – 1.0, these HCFCs ODP have less ODP, i.e. 0.01 – 0.5. Whereas in term of Global Warming Potential (GWP), in comparison to CFCs that have GWP 4,680 – 10,720, HCFCs have less GWP, i.e. 76 – 2,270.

There are a few exceptions for “essential uses”, where no acceptable substitutes have been found (for example, in the metered dose inhalers commonly used to treat asthma and other respiratory problems) or Halon fire suppression systems used in submarines and aircraft (but not in general industry).

The substances in Group I of Annex A are:

  • CFCl3 (CFC-11)
  • CF2Cl2 (CFC-12)
  • C2F3Cl3 (CFC-113)
  • C2F4Cl2(CFC-114) [ie Freon]
  • C2F5Cl (CFC-115)

I see no reason to doubt this info but be diligent and aware of the source!

Thus Freon is given a pass, at least for the next few years, from the restrictions of the Montreal Protocol and indeed is considered to be a hard to replace chemical in an “essential use” in uranium enrichment.

Paducah (again) and significance of the level of CFC released there

An article in The Age, “Nuclear power’s sick legacy” (Caldicott [the same author as above], 2006), mentions that Paducah works as an enrichment facility for other countries (Australia). It also gives a short account of many of the possible negative side-effects perceived to be risks with nuclear power.

I found a blogpost with some responses to Caldicott that  it claims were provided by Elizabeth Stuckle of USEC:

Caldicott Assertion A: Uranium enrichment uses 93 percent of the CFC gas released annually in the United States.

USEC Response A: That calculation is based on 2001 data, when USEC was operating two enrichment facilities. That year, USEC consolidated production at its Paducah plant.The shutdown of the Portsmouth, OH plant and improvements made in control of CFCs at Paducah have enabled USEC to reduce CFC emissions by about two-thirds. The Paducah gaseous diffusion plant was built in the 1950s. USEC plans to replace it with highly efficient gas centrifuge technology, which will use no CFCs. The American Centrifuge Plant is expected to begin operations later this decade.

Caldicott Assertion B: Uranium enrichment uses electricity generated by coal-fired plants.

USEC Response B: USEC purchases the majority of its electricity from the Tennessee Valley Authority, which produces electricity using a supply mix of 61% coal, 29% nuclear and 9% hydropower.The remainder of USEC’s purchased power comes primarily from natural gas and nuclear plants.

Neither claim it seems is wrong according to these USEC responses.

Indeed if we consider the 93% claim and the retort that this has been reduced by two-thirds then, assuming all other outputs to be constant (!), the current level would be 38% (7 + 93/3) of the former level and the Paducah output would then be 82% (31 / 7 + 31) of the CFC gas release annually in the US albeit a substantially smaller absolute amount.

In the USEC Annual Report 2009 (160 pages) the only mentions of Freon/CFC are with respect to continuation of operation of Paducah Gaseous Diffusion Plant (GDP):

The Paducah GDP uses Freon as the primary process coolant. The production of Freon in the United States was terminated in 1995 and Freon is no longer commercially available. We expect our current supply of Freon to be sufficient to support at least 10 years of continued operations at current use rates.

It is significant to me that there is no mention in this document of Freon being damaging, nor of looking for a replacement and I’ve found nothing to suggest that any of the $200 Million USD of profit might be used to attempt to reduce the reliance on Freon or through R&D mitigate the volume of gas released. As an aside it also struck me how the Paducah facility was started by the US Government and is leased to USEC and that USEC thus avoid some deal of liability should their be a major environmental disaster involving the facility; they also avoid decommissioning costs this way (page 7). The report is well worth a peruse, at least I found it quite fascinating (reliance on coal prices for example), it’s highly detailed and includes a glossary.

Summary

Freon release in uranium enrichment

So it seems that several methods of uranium enrichment require large amounts of cooling including the most popular current method, centrifugal separation, and that one widely used method of cooling is using Freon (“CFC 114”).

Indeed given the US figures from Coolreferat.com and from Stuckle (of USEC) it seems that Freon released during uranium enrichment amounts to a large proportion of all Freon release in the US and thus that it is likely to contribute significantly to global warming both in the US and in other countries involved in uranium enrichment whether by gaseous diffussion, centrifugal separation or aerodynamic separation or other means requiring Freon for cooling. Freon use in uranium enrichment appears likely not to reduce for at least 10 years at which point current supplies are set to run out.

Postscript

I realise this is not a thorough analysis but hope that if you are trying to get started on this topic that the links and quotes provided here are helpful. Particularly in question is whether still Freon contributes significantly to global warming.

If you have information about mitigation, of Freon use or release, or about any error in premise or conclusion in this article then please let me know via the comments, thanks.

TL;DR

Read this from coolreferat.com, it’s really good.

 

2 Responses to "CFCs and Nuclear Power"

Jude says:

Fascinating, and just one more piece of information that the “clean green nuclear” supporters would like people not to know!

admin says:

The US were developing a laser isotope separation system called ALVIS which was coming to production status in the 90s but was shelved for cost reasons – it was intended as part of the development of ALVIS to engineer out the use of CFC. Like you say it’s not a surprise that 50s tech used Freon but they’ve moved from GD to centrifuge and are still using Freon.

I don’t think it washes to say that reliance on HCFC-114 is simply historic. Other sweeping changes have been introduced and great technological advances (eg in centrifuge construction) have been made.

Is non-CFC based cooling really that hard? (I honestly don’t know the answer to that). We need an answer if enriched uranium fueled reactors are to be a large part of the future of nuclear power generation though …

http://en.wikipedia.org/wiki/Atomic_vapor_laser_isotope_separation – background
http://www.osti.gov/bridge/purl.cover.jsp?purl=/10102839-PDTP1e/native/ – Gov info
http://www.usec.com/newsroom/newsreleases/usecinc/1999/1999-06-09-usec-inc-suspends-avlis.htm – USEC announcement
http://www.globalsecurity.org/wmd/intro/u-centrifuge.htm – centrifuges


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