True minimization of used nuclear fuel “waste” can only be achieved by recycling the used fuel through fast-spectrum reactors (FSRs). Otherwise the so-called transuranics (TRUs), Pu, Am, etc., in the used fuel will remain radioactive for close to 400,000 years before the radioactivity level returns to the background level equal to the original uranium.
Consuming the TRUs in FSR types of small modular reactors (SMRs) eliminates the long-term radiotoxicity by eliminating the heavy atoms themselves, splitting them and extracting copious non-carbon energy. Only split atom fission products (FPs) are left, about 70% of which are stable non-radioactive atoms immediately, while the remainder decay in days, weeks or months, with only two isotopes of importance having 30-year half-lives, Sr-90 and Cs-137. Today those are the only radioactive fission products of note left in the oldest Pickering used fuel bundles.
Even those two radioactive isotopes can be extracted according to a CNL expert who noted: “Separation of Cs-137 and Sr-90 from other FPs in a reprocessing waste stream is technically feasible and not difficult at all to me”.
Recycling of used CANDU fuel is part of the modus operandi of at least two of the SMR types considered in Canada at present. Both are FSRs, the SSR-W of MOLTEX and the ARC-100 of Advanced Reactor Concepts. They use variations of electrorefining, or pyroprocessing, that was worked out by the Argonne National Laboratories in the USA and operating since the 1980s. Its only residues are FPs, with all else being recycled.
This reduces the used nuclear fuel immediately to 1%, the FPs. And even those turn relatively quickly into non-radioactive atoms and minerals, platinum-group metals at higher concentrations than the best ores in Africa, increasingly scarce rare earths needed for solar panels and wind turbine motors, and valuable noble gases.
Continuing along the path to a DGR deprives humanity of $ 60 trillion non-carbon electricity via the current 60,000 tons of used CANDU fuel. Recycling provides Canadian enriched starting fuel for the planned SMRs, avoiding importing enriched U235 at twice the cost. And it assures Canada of a home-grown non-carbon fuel supply for centuries.
The Adaptive Phased Management plan is easily changed to recycling by the NWMO, since it was created by the NWMO itself in 2005 and agreed to by Parliament in 2007. The Nuclear Fuel Waste Act of 2002 in its Article 20(2) even provides the legal underpinnings for such a change in direction that adopts new methods of nuclear waste management. Recycling is such a new method.
Recycling provides the only approach to reach the ultimate minimum for nuclear fuel waste. It also maximizes the yield of non-carbon energy from our uranium resources.
Since already two of the SMR vendors are proposing recycling as part of their operating procedure, the NWMO must reexamine its current focus on its non-productive DGR and adopt recycling as its new mandate.