Decisive Switzerland24 July 2009
Switzerland has taken a significant step forward by choosing potential areas suitable for a deep geological repository. By Corrina Thomson
On 6 November 2008, the Swiss Federal Office of Energy announced proposals made by the Swiss National Cooperative for the Disposal of Radioactive Waste (Nagra) to identify potential siting regions for deep waste repositories. The first stage of the process began in April 2008 and is expected to take 10 years.
Nagra is responsible for identifying potential regions to site repositories based on the scientific and technical criteria set out in the plan. As such, the organisation has proposed three regions for a high-level waste (HLW) repository. In all of these the preferred host rock formation, the Opalinus Clay, occurs with a suitable extent and depth, according to Nagra’s research. In order to design and construct the repository safely, the host rock area needs to be at least 6km2 (600 hectares, or 2.3 mi2), with a usable width of at least 1.5km.
For low- and intermediate-level waste (LLW and ILW), six regions with the host rocks Opalinus Clay, Effingen Beds, Brauner Dogger and the marl formations of the Helveticum have been proposed. In order to design and construct the caverns properly, the host rock needs to be 3km2, with a usable width of at least 1km.
In addition to host rock type, one of the factors that affected the choice was tectonics (rock structure). Areas of rock that had strong deformation, such as in the Alps, and areas with large faults were excluded as a precaution. Nagra also excluded sections below deep channels that were partly gouged out of the rock during the last ice ages. In the first stage, the main focus was on identifying the suitable areas based on safety and geological criteria.
At the beginning of the first stage, the Federal Government contacted the affected cantons and formed a committee of cantons that has the power to make recommendations. Neighbouring countries are also informed at each stage and the public is kept informed at regular intervals.
In the second stage, the focus is on consultation. The proposed siting regions have an opportunity to participate in studies into the socioeconomic effects and spatial planning impact. The various sites also have to be compared from the point of view of safety before Nagra can propose at least two sites for both HLW and the LLW/ILW repository. Regional participation gives the public an opportunity to be involved and voice concerns.
In stage three, the remaining potential sites are examined in greater detail. Geological studies will be carried out, including drilling exploration shafts.
Before applications for general licences can be submitted, the principles governing compensation measures and the monitoring of social, economic and ecological impact have to be drawn up, and the question of the form of compensation will be addressed.
At the end of stage three, there is the possibility to call for a national referendum on whether or not the Federal Council grants the general licence and whether or not this is ratified by parliament.
The five Swiss nuclear reactors: Leibstadt, Mühleberg, Beznau 1&2 and Gösgen produce around 75t of spent fuel a year. Depending on the operating lifetime of the individual plants, this will result in a total of around 3000–4300t. Packaged in disposal containers, this is the equivalent of around 7325m3.
If the plants have a 50-year life, Nagra has calculated that the total volume of LLW and ILW (including disposal containers) will be around 60,000m3. Around half of this is from decommissioning. Waste from medicine, industry and research constitutes an additional volume of about 33,000m3 of LLW and ILW.
In Switzerland, waste is divided into HLW – spent fuel not destined for reprocessing, vitrified fission product solutions and alpha-emitting waste that exceeds 20,000Bq/g of conditioned waste; and LLW and ILW which are all other radioactive wastes. A preliminary allocation of alpha-emitting waste to either the HLW or LLW/ILW repository will be made but the final decision on category will rest on results of safety analyses for the repository sites.
No deep geological disposal is deemed necessary for waste with short half-lives. These are wastes containing nuclides with half-lives shorter than 60 days or wastes that decay to below clearance level within 30 years of their production.
The current and future costs of managing waste from nuclear power is contained in the price of electricity. For each kWh of nuclear electricity, the consumer pays around 1 rappen (USD0.0092) towards waste management. This includes decommissioning the nuclear power plants, waste transport, interim storage and deep geological disposal, including the necessary research and investigations.
The Federal Government is responsible for collecting the waste from medicine, industry and research. The producers in these cases pay a fee for this service.
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