Finnish utility Teollisuuden Voima Oyj (TVO) has today submitted an environmental impact assessment (EIA) programme to the Ministry of Economic Affairs and Employment on very low-level radioactive waste disposal at the Olkiluoto nuclear power plant. The alternatives are constructing a new near-surface disposal facility or expanding the deep geological repository currently in use.

Very low-level waste includes, for example, protective plastics and protective clothing that have been used during maintenance outages at a nuclear power plant. A disposal facility for such waste would comprise a structure built close to the ground, usually on the ground. The space would consist of a waste backfill and various structural layers above and below it. Drainage and a water collection system will also be built in connection with the bottom, with which the quality of the water seeping through the space can be monitored. Waste placed on top of the substructure is enclosed in waste packages. The size of the proposed facility at Olkiluoto is planned to be 90 metres by 115 metres. Waste packages would be disposed of in the facility every five years, and the part of the space filled with waste would then be temporarily sealed.

TVO noted that similar disposal facilities have been in use in other countries for a long time, but in Finland this would be the first implementation. In Sweden, for example, a similar disposal facility has been in operation since 1993.

Low and intermediate-level operating waste generated at the Olkiluoto plant is currently disposed of in the VLJ repository. It was commissioned in 1992 and consists of two rock silos, a hall connecting the two and auxiliary facilities constructed at a depth of 60-100 metres inside the bedrock. Low-level waste is deposited in the rock silo inside a concrete box, while a silo of steel-reinforced concrete has been constructed for intermediate-level waste in the other rock silo. The low-level waste is packed into 200-liter drums and compressed to half of its volume using a hydraulic press. The radioactivity of the containers is measured before storage. The silo for low-level waste has a capacity of about 5000 cubic metres, while the capacity of the intermediate-level waste silo is about 3500 cubic metres.

The EIA programme. the first step in the environmental impact assessment procedure. concerns the investigations and arrangements required to assess the environmental impact of the project, and is prepared by the party responsible for it. The Ministry of Economic Affairs and Employment (TEM) acts as the coordinating authority.

The ministry said it will now request authorities and corporations to submit statements on the programme. It will also organise a public consultation for citizens and communities. The consultation period is between 21 August and 21 September. The submitted opinions and statements will be published on TEM's website.

All statements and opinions presented at the consultations will be taken into consideration in the ministry's statement on the EIA programme. After the programme phase, the EIA procedure will continue with the EIA report.

Researched and written by World Nuclear News