JÁCHYMOV RADON WATER
ORIGIN OF RADON WATER
The wealth of Jáchymov in the form of radon water was already known and used by medieval miners. Records written by mining physicians in Jáchymov mention that miners suffering from painful diseases used to visit flooded parts of the mines where they bathed in the water. They observed that the water helped to relieve their pain at least partially. However, the true significance of this water remained unknown for centuries.
Radon water in the underground of Jáchymov is created through a combination of climatic and geological conditions. Rainwater penetrates cracks and vein structures within the granite massif filled with dolomite, carbonate or quartz formations and gradually reaches depths of around one kilometre. Among the important ore veins in this area are Stella (Hvězda) and Evangelist. As the water passes through these vein systems it becomes enriched with radon – a light radioactive gas produced during the decay of radium in surrounding rocks.
The age of the water used in spa treatments today is estimated by experts from Charles University at approximately 30–35 thousand years. Radon-222 contained in the water produces soft ionising alpha radiation generated by the decay of radium and uranium. The gas was discovered in 1900 by the German physicist Friedrich Dorn and the name radon has been used since 1923. It is a colourless gas without taste or smell.
Radon contained in the water penetrates the bloodstream only minimally and its biological half-life in the human body is about twenty minutes, which corresponds roughly to the duration of a spa bath. Spa guests therefore do not need to worry that radon remains in the body after the treatment. The radon content in spa baths is strictly controlled and considered safe. Before beginning treatment each patient undergoes clinical and biochemical examinations.
DISCOVERY OF THE HEALING EFFECTS
According to preserved records, the first person who enjoyed baths in water from the Jáchymov underground outside the mines themselves was Emperor Matthias II at the beginning of the seventeenth century.
After the discovery of radium in 1898, waste from the factory producing uranium paints was used to artificially activate water. Already at that time it was suspected that radium water might have therapeutic effects. Professor Eduard Neusser, head of the Second Department of Internal Medicine at the General Hospital in Vienna, therefore requested half a ton of this waste from the mining administration in Jáchymov in order to use it for medical research.
On 7 January 1904 the physicists Stefan Meyer and Heinrich Mache arrived in Jáchymov from Vienna to compare the radioactivity of local waters with springs in other Czech spa towns. At the face of the Schweizer vein on the second level of the Werner mine they discovered what was at that time the most radioactive water in the world, measuring approximately 2500 Bq per litre.
However, the mining administrator Ing. Josef Štěp discovered further springs on the Daniel level of the same mine whose radioactivity reached approximately 7000 Bq per litre. These springs were later named after their discoverer as the Štěp springs. The water had a temperature of about 10.5 °C and a yield of roughly 13 litres per minute. During later ore mining after 1945 above the Daniel level these springs disappeared.
The discovery of the Štěp springs attracted attention in Vienna as well. The imperial minister Count Buquoy invited Josef Štěp to Vienna for discussions. Representatives of the town were invited as well, and it was there that the idea of establishing spa facilities in Jáchymov was first discussed. While Ing. Štěp continued his research on the radioactivity of the springs underground, MUDr. Leopold Gottlieb examined the effects of the water on patients in the first spa facilities.
SPRINGS AND THEIR USE
Originally the Štěp springs from the Rovnost mine were used for spa treatment. The water was carried to the house of the baker Kühn by the retired miner Josef Prennig in a mining basket on his back. Later these springs were led into the hall of the spa building, today the Agricola Spa Centre, where they were used for drinking cures.
Later the Curie spring in the Svornost mine was also used, although it is now exhausted. This spring was also responsible for flooding the Svornost mine because miners encountered it while sinking the shaft. The bottom of the shaft is therefore today deeper than the levels currently used in the mine.
Today the Jáchymov Spa uses the springs Hildebrand (1926), Becquerel (1928), Prokop, Evangelista and HE-1 (1952) and the spring HG-1, which was renamed Běhounek on 3 May 1952. The youngest spring is Agricola, discovered in the year 2000.
While the Curie, Hildebrand and Becquerel springs were discovered accidentally, the others were located deliberately by drilling. The drilling platform had to be dismantled on the surface, transported underground and assembled again in an excavated chamber.
TRANSPORT OF RADON WATER TO THE SPA HOUSES
Every day approximately 550 cubic metres of radon water flow from the Svornost mine to the spa buildings. About 350 cubic metres are used for therapeutic baths, while the rest is used to operate heat pumps in the Svornost mine. Underground work continues to search for additional springs and to repair and explore old mining workings.
Radon-222 does not escape during transport from the mine to the spa because the water remains hermetically sealed in pipelines from the source to the bath. The radon content is measured both at the spring and immediately before the bath. The spa therefore maintains its own dosimetric laboratory.
On the twelfth level of the Svornost mine there is a retention tank into which water from the boreholes flows under its own pressure through pipelines. From there it is pumped approximately 390 metres upward to the Barbora level, where another reservoir is located. From there the water flows by gravity through a pipeline about 2880 metres long along the Curie adit to the portal of the Curie adit. Just before the portal there is a backup reservoir partially protruding above the surface. From this point the water is pumped to the individual spa houses – Běhounek, Radium Palace, Agricola and Curie.
