Nuclear Waste Disposal Sea-Based Nuclear Waste Solutions Ambroise PIGNIER ERNW - 2010.

Nuclear Waste Nuclear Waste DisposalDisposal

Sea-Based Nuclear Waste Sea-Based Nuclear Waste SolutionsSolutions

Ambroise PIGNIERERNW - 2010

Sea-Based Nuclear Sea-Based Nuclear Waste SolutionsWaste Solutions

I – Why thinking of the sea?I – Why thinking of the sea?

II – We already did it !II – We already did it !

III – 3 different new ideas:III – 3 different new ideas:

1) Sub-Seabed Disposal in Stable 1) Sub-Seabed Disposal in Stable Clay FormationsClay Formations

2) Burial in Subduction Faults2) Burial in Subduction Faults3) Seawater Uranium Cycling (SUC)3) Seawater Uranium Cycling (SUC)

IV - ConclusionIV - Conclusion

Why thinking of Why thinking of the sea?the sea?

Sea-based approaches to the disposal of nuclear Sea-based approaches to the disposal of nuclear waste make it hard for terrorists, rebels, or waste make it hard for terrorists, rebels, or criminals to steal for use in radiological weapons criminals to steal for use in radiological weapons or in nuclear bombs. The enormous volume of or in nuclear bombs. The enormous volume of water in the world's oceans also has a vastly water in the world's oceans also has a vastly greater dilutive capacity than any single land greater dilutive capacity than any single land site in the events of leaks. site in the events of leaks.

Even proponents of land-based geological Even proponents of land-based geological storage sites of radioactive waste must storage sites of radioactive waste must recognize that, without a great deal of recognize that, without a great deal of additional investment and endless political additional investment and endless political arguments, these sites will not have the arguments, these sites will not have the capacity to store all the waste that will be capacity to store all the waste that will be generated in future decades. So studying sea-generated in future decades. So studying sea-based solutions makes eminent sense.based solutions makes eminent sense.

We already did We already did it !it !

During the 1950s, During the 1950s, part of the nuclear part of the nuclear waste from Europe waste from Europe and America were and America were thrown from ships thrown from ships in the Atlantic.in the Atlantic.

We already did We already did it ! (2)it ! (2)

Although this option has been highly Although this option has been highly controversial within the community of nuclear controversial within the community of nuclear engineers and even during its implementation, engineers and even during its implementation, until 1982, more than 100,000 tons of until 1982, more than 100,000 tons of radioactive waste were dumped in concrete radioactive waste were dumped in concrete containers at the bottom Atlantic Ocean, from a containers at the bottom Atlantic Ocean, from a dozen countries, including mainly: dozen countries, including mainly: England England (76%), Switzerland (10%), United States (8%), (76%), Switzerland (10%), United States (8%), Belgium (5%), France (1%). Belgium (5%), France (1%). Some containers must remain sealed about 500 Some containers must remain sealed about 500 years (when the waste is active for thousands of years (when the waste is active for thousands of years) ... years) ...

On May 12, 1993, the Contracting Parties to the On May 12, 1993, the Contracting Parties to the Convention of London have voted to ban the Convention of London have voted to ban the final ocean dumping of radioactive wastefinal ocean dumping of radioactive waste

Sub-Seabed Sub-Seabed Disposal in Stable Disposal in Stable Clay FormationsClay FormationsThe London Dumping Convention prohibits dumping The London Dumping Convention prohibits dumping

nuclear waste at sea, as we saw in 1993. It is not nuclear waste at sea, as we saw in 1993. It is not clear whether this applies to a sub-seabed geological clear whether this applies to a sub-seabed geological disposal solution. Moreover, the Convention will be disposal solution. Moreover, the Convention will be coming up for renewal in the not-too-distant future. coming up for renewal in the not-too-distant future. The situation might change as nuclear waste The situation might change as nuclear waste disposal becomes an ever more pressing problem disposal becomes an ever more pressing problem and land-based solutions appear inadequate.and land-based solutions appear inadequate.

Restarting investigation into sub-seabed disposal in Restarting investigation into sub-seabed disposal in stable clay formations is a commonsensical way to stable clay formations is a commonsensical way to develop a fallback alternative to geological disposal develop a fallback alternative to geological disposal on land. The possibility of creating an international on land. The possibility of creating an international consortium that would ensure that all high-level consortium that would ensure that all high-level nuclear waste from every country in the world would nuclear waste from every country in the world would be buried in a single sub-seabed storage area seems be buried in a single sub-seabed storage area seems very promising.very promising.

Sub-Seabed Sub-Seabed Disposal in Stable Disposal in Stable

Clay Formations (2)Clay Formations (2)The large undersea plain some 1000 kms The large undersea plain some 1000 kms north of Hawaii, stable for some 65 million north of Hawaii, stable for some 65 million years, received special attention.years, received special attention.

Researchers found that the clay muds in Researchers found that the clay muds in such sub-seabed formations had a high such sub-seabed formations had a high capacity for binding radionuclides, so that capacity for binding radionuclides, so that any leakage would be likely to remain any leakage would be likely to remain within the clay for millions of years, by within the clay for millions of years, by which time radioactive emissions would which time radioactive emissions would decline to natural background levels.decline to natural background levels.

Burial in Burial in Subduction FaultsSubduction Faults

A second sub-seabed option has received almost no attention but deserves careful consideration: burying canisters of nuclear waste in Subduction Fault that would carry the waste downward toward the Earth's mantle. 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 remote.

Burial in Burial in Subduction Faults Subduction Faults

(2)(2)Some observers object that earthquake or volcanic Some observers object that earthquake or volcanic activity could cause the canister to leak, and the activity could cause the canister to leak, and the radioactive waste would spew into the sky or onto the radioactive waste would spew into the sky or onto the surface. However, it is possible to place the canisters in surface. However, it is possible to place the canisters in the parts of a subduction zone where there is no volcanic the parts of a subduction zone where there is no volcanic activity, so that they will take millions of years to activity, so that they will take millions of years to migrate to less stable parts, at a time when their level of migrate to less stable parts, at a time when their level of radioactivity will no longer surpass that of the natural radioactivity will no longer surpass that of the natural background.background.

As with the stable clay approach, it would be possible to As with the stable clay approach, it would be possible to bore deep holes into the subduction faults in order to get bore deep holes into the subduction faults in order to get the waste as deep as possible, even though the danger the waste as deep as possible, even though the danger of leakage upward to the seafloor appears to be minimal. of leakage upward to the seafloor appears to be minimal. Radionuclides are heavier than water, so there is also no Radionuclides are heavier than water, so there is also no reason why they should migrate upward to the ocean's reason why they should migrate upward to the ocean's surface.surface.

Seawater Seawater Uranium CyclingUranium CyclingIt is the most crazy idea maybe, but one of It is the most crazy idea maybe, but one of the most efficient. The presence of uranium the most efficient. The presence of uranium in seawater at 3 parts per billion suggests a in seawater at 3 parts per billion suggests a third and final sea-based nuclear waste third and final sea-based nuclear waste solution. WHY?solution. WHY?

Technology already exists to separate this Technology already exists to separate this uranium from seawater, but currently its uranium from seawater, but currently its cost far exceeds the cost of conventional cost far exceeds the cost of conventional uranium mining. One way to lower the cost uranium mining. One way to lower the cost would be to combine the extraction of would be to combine the extraction of uranium with related activities (extraction uranium with related activities (extraction of valuable minerals,…)of valuable minerals,…)

Seawater Seawater Uranium Cycling Uranium Cycling

(2)(2)And there if one considers that every atom of And there if one considers that every atom of uranium extracted reduces the natural level of uranium extracted reduces the natural level of radioactivity of the ocean, an international radioactivity of the ocean, an international monitoring body could grant to a company engaged monitoring body could grant to a company engaged in seawater uranium extraction a license to return to in seawater uranium extraction a license to return to the ocean the same amount of radionuclides than the the ocean the same amount of radionuclides than the uranium extracted. This would permit the company uranium extracted. This would permit the company to dispense in a very diffuse way from a ship to dispense in a very diffuse way from a ship traversing vast expanses of sea a tiny trickle of traversing vast expanses of sea a tiny trickle of radionuclides.radionuclides.

Over time, however, improvements in technology for Over time, however, improvements in technology for extracting uranium would attract more firms and extracting uranium would attract more firms and increase the importance of this method. The total increase the importance of this method. The total amount of uranium in the ocean is immense amount of uranium in the ocean is immense 4,300,000,000 metric tons!4,300,000,000 metric tons!

Seawater Seawater Uranium Cycling Uranium Cycling

(3)(3)While many people might feel consternation While many people might feel consternation at the image of simply pouring at the image of simply pouring radionuclides into the water, a correct radionuclides into the water, a correct scientific view shows this image to be very scientific view shows this image to be very misleading. The gigantic volume of the misleading. The gigantic volume of the ocean and the careful dispersal carried out ocean and the careful dispersal carried out in accordance with international monitoring in accordance with international monitoring would make SUC an admirably safe method. would make SUC an admirably safe method. It would also provide incentives for the It would also provide incentives for the development and deployment of seawater development and deployment of seawater uranium extraction, while lessening the uranium extraction, while lessening the environmental impact of opening new environmental impact of opening new uranium mines on land.uranium mines on land.

ConclusionConclusionWhile objections can--and surely will--be raised to While objections can--and surely will--be raised to each of these sea-based approaches to nuclear each of these sea-based approaches to nuclear waste disposal, it is much harder to oppose them. waste disposal, it is much harder to oppose them. Even though they compete with each other, they Even though they compete with each other, they also support each other in terms of reinforcing the also support each other in terms of reinforcing the general concept of carefully investigating methods general concept of carefully investigating methods of sea-based disposal.of sea-based disposal.

Since the U.S. Government appears to lack the Since the U.S. Government appears to lack the political will to pursue such approaches, other political will to pursue such approaches, other governments, companies, foundations, and NGOs governments, companies, foundations, and NGOs need to begin to support research on them. Relying, need to begin to support research on them. Relying, as we now do, on dozens of nuclear countries each as we now do, on dozens of nuclear countries each to develop and maintain secure geological disposal to develop and maintain secure geological disposal sites for nuclear waste is a thoughtless and sites for nuclear waste is a thoughtless and dangerous approach. The ultimate goal should be to dangerous approach. The ultimate goal should be to devise a nuclear waste solution (not necessarily a devise a nuclear waste solution (not necessarily a sea-based one) that will win international sea-based one) that will win international acceptance and become the long-term one for all acceptance and become the long-term one for all High-Level Waste, and perhaps for Low-Level Waste High-Level Waste, and perhaps for Low-Level Waste as well.as well.