ČEZ completes geological drilling near Temelín in Czechia for an SMR

ČEZ carried out nine geological boreholes near the Temelín Nuclear Power Plant in July. It will use the results in an application for a permit to site a small modular reactor (SMR), which the utility plans to submit to the State Office for Nuclear Safety next year. ČEZ wants to build the first SMR in Czechia near Temelín in the mid-2030s. Last autumn, the company submitted an application for an environmental impact assessment (EIA). The Atomic Act requires the utility to conduct a geological survey, Temelín spokesperson Marek Sviták said today.

The nine boreholes reached depths of between 50 and 200 metres. The aim of the geological survey is to refine data on the geological environment. Geologists use samples to determine, for example, the strength, bulk density and other physical and mechanical properties of the rock. Experts carried out the first survey linked to SMR preparations near Temelín three years ago. At the time, they drilled four boreholes to a depth of 30 metres.

“Geologically, this is a very well-mapped site that is suitable for nuclear power. Surveys were carried out by workers as early as the 1980s, before construction of the first and second Temelín units. Further surveys were conducted in connection with preparations for units three and four. For the modular reactor, this is the second survey, and more will follow,” said Silvana Jirotková, head of SMR development at ČEZ.

Drilling through the hard bedrock progressed at a rate of just under two metres per hour. “We use a core drilling rig with a diamond bit, the hardest natural material. This enables us to extract drill cores even from very hard rock. In this particular case, the rock is paragneiss, which is among the hardest types,” explained geologist Jakub Opršal, who is responsible for the work.

ČEZ plans to begin construction of the SMR in 2029 and complete it in the mid-2030s. The technology will be supplied by British company Rolls-Royce SMR, with which ČEZ signed a strategic cooperation agreement on the development of modular reactors last autumn. ČEZ bought an approximately 20% stake in the British company, paying several billion korunas for it. The cooperation, which is planned to span several decades, envisages ČEZ directly contributing to the development of the new modular reactor technology and their manufacture on a global scale. The project will therefore involve more than simply purchasing or supplying completed units.

The SMR near Temelín will have an electrical output of 470 megawatts, a planned service life of at least 60 years, and will be a pressurised water reactor. Other planned SMRs in Czechia will have the same output. A single reactor at Dukovany currently has an output of more than 500 MWe (electrical megawatts).

The British government organisation Great British Nuclear (GBN) selected Rolls-Royce SMR as its preferred SMR supplier in the UK, giving the company the opportunity to build the first three small modular reactors in Britain.