DGR for spent nuclear fuel is unnecessary, says professor

The need for a Deep Geological Repository (DGR) for spent CANDU nuclear fuel in South Bruce or Ignace, is completely unnecessary since recycling, which eliminates the million-year radiotoxicity of the spent fuel, is much more sensible.
 
Recent OpEd’s in two national newspapers (MacClearn, Globe and Mail, March 19; Walkom, Toronto Star, March 26) described the agonies of the people of South Bruce and Ignace in deciding on whether to accept a DGR for high-level used nuclear fuel on their lands.

There is no need for such agonies. The DGR is not needed. There are better, more productive and societally more useful and acceptable approaches to eliminating Canada’s so-called nuclear fuel “waste”… we can recycle it through fast-spectrum Small Modular Reactors (SMRs). The technology already exists.
 
Firstly, though, we have to call a spade a spade. The “waste” is not waste at all. It is very slightly-used fuel still with over 99 per cent of its energy untapped, able to provide plenty more non-carbon electricity to help mitigate climate change.  Less than one per cent of this uranium fuel has been consumed to create the huge amounts of non-carbon nuclear energy produced since the 1970s in Canada’s CANDU reactors.

How to extract the remaining energy, the other 99 per cent, was already established in the United States in 1951, with a small metal-cooled demonstration reactor, the EBR-1. Full fuel recycling was developed in the ‘80s on a larger version, the EBR-2.
 
Such full-energy extraction with recycling is a much better approach to nuclear “waste management.” It provides about 130 times more non-carbon energy by consuming all of the same used CANDU fuel; thereby, eliminating its long-term, million-year radiotoxicity. Instead, Canada’s Nuclear Waste Management Organization (NWMO) chose a different mandate in 2005, to bury the CANDU “waste” in a planned DGR.
 
A bit more history: the molten-metal-cooled EBR reactors used enriched uranium fuel. Canada went in a different direction using water-cooled reactors, and so did the rest of the world.
 
We designed and built the CANDU reactors fuelled with natural uranium to avoid enriching uranium, since enrichment easily leads to nuclear weapons. The CANDUs were the right reactors for Canada at the time, and the most fuel-efficient of all water-cooled reactors. Yet, even today, they still use only 0.74 per cent of the fuel and leave the remaining 99.26 per cent of the available energy unused. 
 
That’s awfully wasteful compared to using 100 per cent with recycling. It’s like having only one lick of a chocolate bar and throwing the rest away.
 
Yes, the used fuel is highly radiotoxic and will remain so for about 400,000 years - unless we start using the knowledge already developed from 1950-80 on how to recycle the fuel. That is beginning to happen right now with the potential introduction in Canada of many different varieties of SMRs.

SMRs are factory-built reactors - smaller and more economical. They are modular, so that one small reactor can be added at a time as non-carbon energy demand grows, somewhat like adding one wind turbine after another.
 
Crucially, some of these SMRs, called fast-spectrum SMRs, like the EBR reactors, are capable of consuming all of the existing used CANDU fuel, with recycling.
 
New Brunswick Power is supporting the development of two such fast-spectrum SMR designs backed by three levels of government and multi-million-dollar matching grants. Ontario Power Generation (OPG) and the Canadian Nuclear Laboratories are supporting activities directed at recycling efforts.
 
A superb recycling technology with minimal residue was developed in the 1980s in the U.S. by expatriate Canadian, Charles Till, and used with fuel from the 20 MWe fast-spectrum EBR-II reactor. That reactor operated for 30 years, until 1994. The recycling process, one of two now considered for Canada, is still operating outside of Chicago, Illinois, and in Idaho Falls, Idaho.
 
Fast-spectrum SMRs, such as the EBR-II, require either fuel enriched in U235, a minor component of uranium, or can operate with heavier atoms, transuranics, found in used CANDU fuel. By choice, Canada has no enrichment facilities. However, recycling can deliver the required transuranics from that used CANDU fuel. The transuranic atoms that are needed as fuel in the fast-spectrum SMRs, are precisely the heavy atoms that would remain highly radioactive for those 400,000 years.
 
As a result, when the transuranic atoms are extracted from the slightly used fuel stockpiles, and consumed in SMRs, they are eliminated, and so is their 400,000-year radiotoxicity.
 
That eliminates the need for a million-year DGR.  So why build one? The effort and money is better spent on recycling.
 
There are further advantages that can be exploited in terms of profitable simultaneous extraction from the used-fuel stockpiles of the smaller atom fission products. These are the “ashes” that are created as the uranium is split into two atoms to release its nuclear energy. Those “ashes” contain valuable platinum-group metals, rare earths required for solar panels and wind-turbine motors, and useful noble gases, such as xenon and krypton.

All of these atoms have already become stable non-radioactive elements in the oldest used CANDU fuel now stored in Pickering. Only two out of some 200 small atom-types in the “ashes” have lingering radioactivity of any importance. These are Sr-90 and Cs-137, with 30-year half-lives. But to quote an expert at the Canadian Nuclear Laboratories: “Separation of Cs-137 and Sr-90 from other fission products is technically feasible and not difficult at all …”

Those two atom-remains are a small residue that can be stored in a much-smaller shielded containment for a comparatively shorter time, for at most, 10 of their 30-year half-lives instead of 400,000 years.
 
The world has progressed over the past two decades. It is time for the NWMO to rethink its direction. The NWMO’s own Adaptive Phased Management approach gives it the opportunity to change. Even the federal Nuclear Fuel Waste Act of 2002, which created the NWMO, provides in its Section 20(2) the legal framework to choose a new direction as new methodologies become available.

Recycling is such a method.  It is a productive and profitable approach to nuclear “waste” management as opposed to the politically-fraught and rather costly disposal of a resource that can instead be used to produce $60-trillion of non-carbon electricity, and much more process heat energy to boot. The Ontario Nuclear Fund Agreement Trust for nuclear “waste” management can finance such facilities with its current $10-billion, money otherwise squandered on an unnecessary DGR.
 
The decisions by South Bruce and of Ignace would be much more positive with this new direction. Instead of a DGR, both communities should request fast-spectrum SMRs, coupled with a used-fuel recycling facility. That would provide well-paying skilled jobs for centuries while eliminating the long-lived radiotoxicity of the existing used CANDU fuel, quickly and efficiently.

Recycling our spent CANDU fuel could be a win-win situation, uniting communities agonizing over a DGR, providing carbon-free heat energy and electrical generation, highly-skilled jobs, and elimination of toxic stockpiles of spent fuel.
 
Peter Ottensmeyer PhD
Professor Emeritus
University of Toronto
Don Mills, Ontario