Does Finland Have A Solution?

Onkalo in foreground, nuclear power station behind

The builder of the world's first operational geologic deep storage of high-level radioactive waste thinks so.  Posiva, in conjunction with the state energy company,  is nearing the operational date of its facility at Olkiluto on the Baltic Coast.  A repository has been mined in the bedrock at 430 meters below the surface where spent nuclear fuel rods will be encased in copper-iron canisters sheathed in water-absorbing  bentonite.  Once storage wells are filled the connecting tunnels will be backed filled with more bentonite and sealed with concrete.  Is this overkill designed to satisfy nervous Finns?  Hardly, when one considers that plutonium has a half life of 19,000 years, requiring at least 100,000 years to decay to safe levels of radioactivity.  Currently, since the atomic energy era began the world has about 400,000 metric tons of HLW. Most of that is stored in either water pools or dry canisters above ground. These are temporary storage facilities, and particularly vulnerable to catastrophic failures such as earthquakes or terrorist attacks.  What to do with waste that is potentially deadly and remains so for thousands of years has alway been the Achilles heel of the nuclear power industry.  Reprocessing spent fuel remains prohibitively expensive.

The United States attempted to build its own deep geologic storage facility at Yucca Mountain, NV but it never stored a kilo of waste.The project fell victim to geologic and political problems.  The site was subject to water infiltration through its volcanic tuff and seismic faulting (e.g. Bow Ridge fault). Nevadans led by their Senator Harry Reid were not happy being chosen as the site of the nation's only civilian radioactive waste facility, so the NIMBY syndrome set in. The US stores its transuranic waste from weapons production at a facility in New Mexico The Finnish bedrock was chosen for low water permeability. The bedrock also has a lack of faulting that could impact the storage shafts. Once the facility is filled the galleries will be closed in and the surface restored to Nature, around 2120.

Finland seems to have gone to greater lengths studying the geologic stability of its chosen site,  conducting bore hole studies since the 1980s. Posiva is using both geology and materials technology to secure storage of the used fuel rods, and a system of independent barriers to accidental release. Tests have been carried out using canisters containing heating elements and sensors to simulate and detect heat caused by radioactive decay. The tests are a condition of its operating permit.  A factory for encapsulating the rods is built next to the Onkalo repository entrance. Remote controlled transporters will be used to place the containers in their receptacle.  The storage bores are scheduled to begin receiving canisters by the mid 2020s. Onkalo will be the world's first operating radioactive storage facility; construction began in 2004 when other advanced countries including Switzerland, which is farther along than most, were still in the planning stages.  An animation produced by Posiva explaining the facility's features appears below

Acceptance of the facility is high among Finns, but that does not mean the project is without critics. Trust in technology, regulations, and regulators is traditionally high in Finland. The local counsel gave their approval by a vote of 20 to 7 in 2000. While the planning for Onkalo is comprehensive, critics point to possible corrosion of the copper containers. The Swedish Environmental Court found that it could not be definitively proved that copper containers will maintain structural integrity for required 100,000 years. Nevertheless, the Swedish government approved the permit for a storage facility using this technology to be built at Forsmark Critics say the decision to build Onkalo was a foregone conclusion with too few environmental scientists sitting on evaluating committees,--NOT the result of honest scientific debate. The human responsibility for radioactive waste is for all practical purposes, eternal.