High and Low-level waste (HLW) is produced by nuclear reactors. Spent fuel is highly radioactive and hot. HLW accounts for over 95% of the total radioactivity produced in the process of nuclear electricity generation. The amount of HLW worldwide is currently increasing by about 12,000 metric tons every year, which is the equivalent to about 100 double-decker buses or a two-story structure with a footprint the size of a basketball court . A 1000-MW nuclear power plant produces about 27 tonnes of spent nuclear fuel (unreprocessed) every year. In 2010, there was a very roughly estimated 250,000 tons of nuclear HLW to be stored (excluding escaped amounts into the environment from accidents or tests). Japan is estimated to hold 17,000 tons of HLW in storage in 2015. Specially designed interim surface or sub-surface storage of radioactive waste facilities are currently used in many countries pending the availability of a long-term disposal option. Big problem is that what was initially meant to be an "interim" storage is now ....permanent due to desperately slow progress on finding permanent deep land-based sites. There are concerns that over ground existing fuel waste containers are beginning to degrade. "Recognising that long-term management options may require significant time to be achieved, interim storage arrangements may need to be extended beyond the time periods originally envisaged". (World Nuclear Association, January 2016) Safeguards are also required to ensure that neither plutonium nor highly enriched uranium can be pillaged for terrorist activities. The International Atomic Energy Agency (IAE) says there is "a persistent problem with the illicit trafficking in nuclear and other radioactive materials, thefts, losses and other unauthorized activities". The IAEA Illicit Nuclear Trafficking Database notes 1,266 incidents reported by 99 countries over the last 12 years, including 18 incidents involving enriched plutonium trafficking.
Burial in Subduction Faults
A second sub-seabed option has received little attention but deserves careful consideration: burying canisters of nuclear waste in Subduction Faults that would carry the waste downward toward the Earth’s mantle. This approach possesses the virtue of being very permanent,
As the subduction fault would carry the canisters down at a rate of, say, 10 cm per year, the chances of any release
of radionuclides into the biosphere would become increasingly remote.
A California firm, Permanent RadWaste Solutions, has pursued the technology for this option. In addition to the bottom-crawling submarine for digging the holes and delivering the waste, this company has developed a canister technology that becomes more tightly sealed and resistant as the outside pressure increases during the descent of the canister toward the mantle. Some observers object that earthquake or volcanic activity could cause the canister to leak, and the radioactive waste would spew into the sky or onto the surface. However, it is possible to place the canisters in the parts of a subduction zone where there is no volcanic activity, so that they will take millions of years to migrate to less stable parts, at a time when their level of radioactivity will no longer surpass that of the natural background. As with the stable clay approach, it would be possible to bore deep holes into the subduction faults in order to get the waste as deep as possible, even though the danger of leakage upward to the seafloor appears to be minimal. Radionuclides are heavier than water, so there is also no reason why they should migrate upward to the ocean's surface, especially since there is no evidence that bottom-dwelling marine species are concentrated upward into a food pyramid that leads to the surface.
Since governments appear to lack the political will to pursue such approaches, international organizations, companies, foundations, NGOs and ENVIRONMNTALISTS need to begin to support research on Sub-Seabed Disposal. Relying, as we now do, on dozens of nuclear countries each to develop and maintain secure geological disposal sites for nuclear waste is a thoughtless, wasteful and dangerously irresponsible. The ultimate goal should be to devise a nuclear waste solution (not necessarily a sea-based one) that will gain international adherence and become the shared global long-term one for all High-Level Waste, and perhaps for Low-Level Waste as well.
The United States has not seriously considered sub-seabed disposal of spent nuclear fuel (SNF) since 1986, when it ceased funding an international team of scientists known as the Seabed Working Group. 190 This group consisted of about 200 researchers from ten different nations and received significant funding during its active years. 191 The group concluded its work with a call for further research after preliminary testing from 1976 to 1986 at about six sites in the Atlantic and Pacific oceans showed promise for sub-seabed burial of SNF in ocean floor sediment. The United States, which provided most of the group’s funding, withdrew its support in favor of land-based SNF disposal methods around the time that Congress selected Yucca Mountain as a national SNF repository.
What’s noteworthy about nuclear power is that not a lot of the total energy in a fuel rod is actually utilized and turned into electric power. In fact, less than 1% of the total power generated becomes usable electricity. Therefore, the other 99% has to be treated or allowed to decay in a safe way. The best way to do this, economically, is to store it underground in stable areas for thousands of years.
Interresting reading; go to website for full text.