Announcement - Asse II mine

23 November 2017: Values measured in the evacuated inflow waters.

Roughly 12.5 cubic metres of saline influent waters are collected in the Asse II mine every day. The largest part, i.e. 11.5 cubic metres, is captured at the main collection point on the 658 metre level. Only these waters are transported above ground. They have to undergo an appropriate release procedure before they are disposed of. The measuring results show that these waters do not present any radiological risks. All influent waters captured below the 658 metre level remain in the mine.

As long as these waters are stored in the mine, they absorb tritium from the mine air. A number of measures (such as covering the collection tanks, providing separate fresh air supply) ensure that the tritium concentration is kept as low as possible according to the provisions in the atomic and radiation protection laws (minimisation requirement).

In the following paragraphs you will find the current values measured in the evacuated inflow waters. The measured values are checked for plausibility in a first step to ensure that they can be published as soon as possible. Later on, you will find the technically reviewed values in the published reports. It is unlikely, however, that the values need to be changed.

For a better understanding of the measured values, please note the following reference: According to the German Drinking Water Ordinance, the limit value for tritium in drinking water is 100 becquerels per litre (1 becquerel = 1 nuclear disintegration per second).

 

Batch number 12/2017

Amount: 316 cubic metres

Tritium: < 1.3 becquerels per litre (beneath detection limit)

Caesium-137: < 0.79 becquerels per litre (beneath detection limit)

Period of removal: 20 November 2017 - 22 November 2017

 

Batch number 11/2017

Amount: 332 cubic metres

Tritium: 2.1 becquerels per litre

Caesium-137: < 0.9 becquerels per litre (beneath detection limit)

Period of removal: 23 October 2017 - 25 October 2017

 

Batch number 10/2017

Amount: 318 cubic metres

Tritium: < 1.6 becquerels per litre (beneath detection limit)

Caesium-137: < 0.74 becquerels per litre  (beneath detection limit)

Period of removal: 25 September 2017 - 27 September 2017

 

Batch number 09/2017

Amount: 316 cubic metres

Tritium: 3.2 becquerels per litre

Caesium-137: < 0.9 becquerels per litre (beneath detection limit)

Period of removal: 28 August 2017 - 30 August 2017

 

Batch number 08/2017

Amount: 322 cubic metres

Tritium: < 1.4 becquerels per litre (beneath detection limit)

Caesium-137: < 0.61 becquerels per litre (beneath detection limit)

Period of removal: 31 July 2017 - 02 August 2017

 

Batch number 07/2017

Amount: 336 cubic metres

Tritium: 1.7 becquerels per litre

Caesium-137: < 0.59 becquerels per litre (beneath detection limit)

Period of removal: 03 July 2017 - 05 July 2017

 

Detection limit

The detection limit describes the lowest value within a measuring procedure for which the measured parameter (such as the specific activity of radionuclides in a liquid sample) can be reliably determined. The detection limit reflects the sensitivity of the selected analysis procedure. For example, if the activity concentrations of radionuclides are so low that they cannot be determined with a sufficient degree of certainty, the “limit of detection” is indicated. It shows the highest possible activity that may theoretically be present in a sample.

Sampling at the main collection point on the 658 metre level