Jan Lindholm Nejtilluranbrytning (No to Uranium Mining),* 2007-04-27
Attempts to extract radioactive minerals from alum shale in Västergötland dates back to the early 1900s. An attempt to produce radium on an industrial scale began in 1905 by the AB Kolm company. The project became unprofitable and was abandoned in 1915.
A classified report from 1953, "The uranium rich alum slate in Sweden," represents the start of modern activities to mine uranium from alum shale.
Sweden had their own plans for the development of nuclear power and possibly weapons during the 1950s and 60s which relied on producing plutonium in heavy water reactors from natural uranium. The idea was to be independent from external sources and expensive technology for enriching uranium. This line was abandoned at the end of the 1960s and Sweden stopped all projects for developing a national nuclear weapon. Sweden then embarked on a massive project based on American light water reactors.
The Ranstad uranium mining project began in 1959 and continued to 1983. Most of the uranium on the open market in the early days was bought by the US military. This created a situation with artificially high uranium prices and a shortage on the market. Ranstad started production in 1965 but was never profitable. Mining continued up to 1969 on a reduced scale. A total of 215 tonnes of uranium oxide was produced.
Uranium prices started to increase after the first oil crises in 1973, and it was deemed profitable to restart production in Ranstad. The Swedish mining company LKAB became a partner in the company and took over responsibility for running the mining operations. A proposal from LKAB was put to the Swedish Government in 1975 for consideration. The proposal was withdrawn after massive protests from amongst others the Skövde Environmental Forum (Skövde Miljöforum), and the towns of Skövde and Falköping.
A new proposal that included other minerals besides uranium was put together by LKAB in 1977, but this was also stopped due to massive protests and a veto by the towns of Skövde and Falköping. That put a final stop to any future plans for mining uranium from alum shale in Västergötland (1).
The concession for uranium mining in Ranstad was stopped in 1984, and the plant was sold to a private company. The responsibility for restoring the tailings deposits and mining pits rested on the Swedish government. The County Administration of Skaraborg (later Västra Götaland) drew up plans for the restoration and the final document ”Reclamation Plan for the Ranstad Mine Area” (“Efterbehandlingsplan för gruvområdet i Ranstad”) in January 1990, governed the restoration. Studsvik AB (formerly called AB Atomenergi) was engaged to carry out the plans and the work took place from 1990 to 1993.
In order to restore the open pit area it was essential to block all possible contamination of the sandstone aquifer. A tunnel running from the pit under the Billingen mountain that was used to transport shale for crushing and processing, reached down into the sandstone layer, and had to be blocked. The tunnel was plugged using bentonite and concrete.
The walls of the 2,000 x 100 m pit were graded and the bottom was covered with waste material from the mining. Ground water was then allowed to fill the pit to a level of 176.5 m (the surrounding hilltops are at 300 m above sea level) and the resulting lake was called Tranbärssjön. The surface run-off goes untreated via Pösan to Lake Hornborga.
Tailings (wastes from uranium extraction) covered an area of 28 ha which had to be reduced down to 23 ha. To prevent water from penetrating the tailings, the area was covered by a 1.8 m. thick layer of bentonite, limestone and gravel. A system of dikes was made to collect any water seeping out from the tailings. This water was then collected in dams and treated before release into the recipient, Marbäcken.
The cost to date has been 180 MSEK and it is estimated that it will cost 70 MSEK to complete the sanitation of the production facilities at Ranstad.
The high concentration of uranium and other metals in the water from Tranbärssjön makes it unsuitable for grazing animals due to heavy metal toxicity. The levels of uranium in Hornborgaån are much higher than would be expected from the Ranstad run-off . The large number of sites in the area that have been mined for limestone are probably responsible for most of the leakage of uranium as the alum shale lies exposed at many of these sites.
Government regulatory agencies consider the toxic effects of uranium as a heavy metal to be the main environmental concern. SSI (The Swedish Radiation Protection Athority) has concluded that “no adverse radiological consequences are expected in the future” (2).
* The network Nejtilluranbrytning (No to Uranium Mining) tries to report on events related to uranium prospecting and to provide information on the consequences uranium mining has for the environment.
1. The mining area prior to restoration.
2. Diagram of the restoration of the mining area.
3. Blocking the tunnel to prevent leakage from the lake.
4. A diagram of the layers of sedementary rock at Ranstad.
5. Waste deposit area.
6. Run-off from the waste deposit.
7. The processing plant at Ranstad in 1978.
8. Map of the mining and waste area.
9. Untreated wastes.
10. Structure of the coverage of the waste deposit.
Footnotes
(1) In 2005 and 2006 there was a new attempt to exploit the alum shale in Västra Götaland and Närke. Several companies, Svenska Skifferaktiebolaget, Mawson Resources and Continental Precious Minerals Inc., applied for prospecting rights in a large area covering most of the cambrium silur triangle of Billingen – Ålleberg- Gerumsberget. The Mining Inspectorate of Sweden (Bergsstaten) received massive protests from The County Administration of Västergötland, all affected cities, as well as from farmers and other organisations. The proposals were all turned down and the alum shale of Västergötland is safe for the time being. However, on April 15 2007, Continental Precious Minerals Inc. filed an appeal to reverse the decision of The Mining Inspectorate of Sweden not to grant them prospecting rights in Billingen. Though there may not be any prospecting in Västergötland there are many concessions for uranium prospecting in Sweden. Drilling has started in Jämtland and Lappland. There are also concessions for prospecting in Närke.
(2) Källan är Länsstyrelsens beslut för återställning av Ranstad från jauari 1990 2475-765-88. "Statens strålskyddsinstitut skall enligt strålskyddslagens bestämmelser ge godkännanden för verksamheten vad avser strålskyddsrelaterade frågor. I SSI:s ansvar ligger, förutom att beakta rena arbetarskyddsfrågor och skyddet av allmänheten, även att ur radiologiska synpunkter beakta skyddet av djur, växter och miljön i övrigt.
SSI har granskat efterbehandiingsplanen och företagets rapport om de radiologiska undersökningar som utförts i vattendragen runt Ranstad 1961 - 1987. SSI:s slutsats är "att externstrålning, radonavgång och aktivitet av radioaktiva ämnen i omgivande vattendrag, både i dag och i framtiden, ligger inom den naturliga variationen. Några oacceptabla radiologiska konsekvenser förväntas därför inte uppstå”."