Finland’s Radiation & Nuclear Safety Authority (STUK – Säteilyturvakeskus) has issued its decision on the periodic safety assessment (PSA) of Teollisuuden Voima Oyj’s (TVO's) final disposal repository for low & intermediate level waste at the Olkiluoto NPP. According to STUK, the level of safety of the facility is good in terms of both operational safety and long-term safety. STUK states that the licensee has the required procedures and resources available for the continuation of repository operation.

TVO submitted the PSA for the repository to STUK in December 2021. Under the Nuclear Energy Act, a PSA is required on the operating waste repository at intervals of 15 years. The previous assessment was conducted in 2006 and the next is scheduled for the end of 2036.

The Olkiluoto operating waste repository was completed in 1992. The silos at the repository are designed for the final disposal of low-level maintenance waste and solidified liquid wastes generated during NPP operation. Used fuel generated at the Olkiluoto NPP, is for the time being stored in an interim storage. Posiva Oy expects to start the safe final disposal of used fuel in mid-2020s.

STUK said operation of the waste disposal facility can be continued until the end of 2051 in accordance with the current permit. Olkiluoto NPP generates low and intermediate-level waste, which is disposed of in the facility built in the bedrock of the power plant area. The disposal facility is also used for storing and disposing of radioactive waste generated by industry, medical care, and research.

"The underground rooms currently in use at the disposal facility were commissioned by decision of the Finnish Government in 1992. Since then, we have regularly reviewed the conditions for the safe operation of the facility,” said STUK Senior Inspector Ari Luukkonen. “The safety assessment has not revealed any shortcomings or defects that would pose a radiation hazard to people or the environment, now or in the future.”

A disposal facility was excavated about 100 metres deep in the bedrock of the Olkiluoto NPP area. The repository will also later be used for low-level decommissioning from the NPP.

Image: Olkiluoto's operating waste repository (courtesy of TVO)