Boreholes

Geological boreholes provide a direct insight into the underground geological environment and its structure. These exploratory boreholes are also called deep boreholes.

Up-to-date information on the deep boreholes going into operation in 2019 can be found on the website “deep boreholes” (in German).

Two drilling techniques are widely used:

When using a roller bit, the rock is crushed at the bottom of the borehole. A fluid that flushes the bits of rock (drill cuttings) to the earth's surface is pumped through the drill rod. This drilling fluid is circulated in a closed cycle.

The more complex cored boreholes only crush the rock surrounding the borehole. The so-called drill core inside the core drill bit remains intact. The drill core can be removed and transported to the earth's surface where the rock can be investiagted more closely.

To complement these investigations, various borehole measurements, so-called logs, as well as further hydrogeological and rock-mechanical tests are conducted.
In accordance with the Nuclear Energy Act, deep boreholes conducted by Nagra require a permit granted by DETEC (Federal Department of the Environment, Transport, Energy and Communications). In the autumn of 2016, Nagra submitted sixteen corresponding applications (eight each for Jura Ost and Zürich Nordost). The Federal authorities examine the applications in cooperation with the corresponding cantons. Once the permit for a deep borehole has been granted, the drill site can be built. The first boreholes are scheduled to begin operating in early 2019.

To date, Nagra has drilled around 1000 to 2500 metres of borehole in Northern Switzerland as part of the investigation programme for the demonstration of disposal feasibility (Entsorgungsnachweis). The boreholes are:

Exploration applications

With a view to Stage 3 of the Sectoral Plan process, Nagra submitted applications for permits for eight exploratory boreholes in each of the siting regions Jura Ost and Zürich Nordost in September 2016. The applications for the Nördlich Lägern region followed in August 2017.

The applications were open for public inspection in the affected communities in the Jura Ost region between 27^th February and 28^th March. The inspection period in Zürich Nordost ran from 13^th March until 26^th April. The public inspection in Nördlich Lägern began on on 1^st November 2017. All public inspections were completed on 16^th January 2018. On 21^th August 2018, the first three permits (Bülach, Marthalen and Trüllikon 1) have already been granted by DETEC and others are expected in the coming months.

The planned exploratory boreholes in the Jura Ost region are Zeihen, Effingen 1, Riniken 2, Remigen 1, Remigen 2, Bözberg 1, Bözberg 2 and Effingen 2.

The planned exploratory boreholes in the Nördlich Lägern region are Weiach, Bülach, Stadel 1, Eglisau, Stadel 2, Glattfelden, Stadel 3.

The planned exploratory boreholes in the Zürich Nordost region are Uhwiesen, Laufen, Trüllikon 1, Trüllikon 2, Rheinau, Dachsen, Marthalen, Trüllikon 3.