On 30 September 2019, the Swedish Radiation Safety Authority (SSM) provided an opinion to the government on the supplementary information on copper corrosion provided by the nuclear waste company SKB in the spring of 2019. In the opinion the regulator said that it did not re-evaluate or change its previous position that the planned repository for nuclear fuel repository can be built to be safe. SSM’s review work prior to providing the opinion included support from the reports of three external expert groups. Three consulting groups were used. One of the groups was very critical in its assessment of how the nuclear waste company SKB chose to answer the questions raised by the Land and Environmental Court regarding copper corrosion when it rejected the application to build the repository on 23 January 2018.
The three consultants that SSM used to supplement its review were Galson Sciences Ltd, Southwest Research Institute and Szakálos Materials Science AB, all of which provided documentation to SSM. The most critical report is written by Peter Szakálos and Christofer Leygraf from KTH – the Royal Institute of Technology in Stockholm – and reinforces the criticism previously made about corrosion and the ability of copper to be used for encapsulation in the KBS method's barrier system. Professor Leygraf is one of the most distinguished copper corrosion experts in Sweden and his profile from the university’s web site can be found below.
The KTH researchers conclude that the nuclear waste company SKB has not submitted sufficient new information about the so-called the sauna effect (salt enrichment) and its effect on pitting and stress corrosion. The researchers also believe that the company has not provided sufficient new information about the risk of stress corrosion, hydrogen embrittlement and hydrogen disease and how radiation affects the copper canister. In summary, the researchers believe that there is still a lack of evidence on all the five points concerning canister integrity that the Land and Environment Court said must be investigate further in the court’s opinion to the government in January 2018.
The KTH researchers have also written an opinion directly to the government together with additional researchers from KTH and the former corrosion expert from SSM, Jan Linder. The opinion is below.
In mid-November 2019, SSM published the three consultant reports in an SSM report (SSM 2019:22). The report from Szakálos and Leygraf is recorded separately by SSM and MKG has read it. The report is available for download below. The SSM report is also below.
Opinion from the KTH researchers on copper corrosion to the government 190913 >>
