SHAFTS & CAVERNS | TECHNICAL


the vault could be located deeper than first thought - and at a depth more comparable to that offered by Oskarshamn, at around 470m below the surface. With extra distance from the surface, the shielding


offered at Forsmark would be thickened, effectively. Coupled with favourable groundwater characteristics, and less need for excavation it was argued to open up the storage tunnels, it was added, the balance tilted towards Forsmark. Aspects related to post-closure safety were decisive in choosing Forsmark, WTC 2025 heard. After many years of studies and field research at


sites across the country, starting in the late 1970s, SKB made its choice in 2009, in favour of Forsmark to host the deep geological repository. Hundreds of scientific reports had been produced by then, 25 cored boreholes drilled (19 to more than 500m depth; nine more to more than 1km depth, says SKB in its project briefing), and soil boreholes were sunk, too. There were also percussion drilled boreholes, and geo-scientific and ecological surface mapping. In 2011, SKB filed an application to build and operate the high-level storage facility at Forsmark.


ÄSPÖ HARD ROCK LABORATORY Whichever of the competing host sites for spent fuel would come to be chosen, the Äspö Hard Rock Laboratory was developed underground to provide important research data to the entire selection process. It just happened to be located in Oskarshamn municipality, slightly north of the city of Oskarshamn.


Äspö is where much of Sweden’s research to develop


a final repository for spent fuel has taken place. The research has involved international collaboration. Survey work at Äspö began in the mid-1980s. The


tunnels were excavated over 1990-95 and are nearly 500m below the surface. The research, development and demonstration programme envisaged for the network of tunnels was planned to last until 2010. Part of the early works involved cross-checking


and verification of geological data from the extensive excavations with that predicted from the site investigations from the surface, and sampling with boreholes. These methods were then employed in site investigations carried out for the competing host sites, nearby in Oskarshamn area and, much farther north, at Forsmark. Underground, the Äspö complex has been used to


test different technological solutions at full scale in a realistic setting, says SKB. These studies included examining the interaction of the sealed canisters and bentonite clay that would pack around each vessel in its silo, and also perform experiments on the use of the rock as a barrier. Equipment systems for deposition of canisters were


also tested. The rock laboratory was extended over 2011-12,


adding another 350m of tunnels. SKB says that in recent years the activities at the Äspö laboratory have focused more on adapting technology and methods to the industrial process to be used in operating the real repository, to be built at Forsmark.


Above: Construction is underway to extend the underground repository for short-lived radioactive waste at SKB’s Forsmark site October 2025 | 15


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45