ČEZ to Invest CZK 3.8 billion in Modernisation of Temelín This Year

Completing the transition to a longer fuel cycle, continuing to modernise the control system, and expanding the use of artificial intelligence and advanced control methods. These are the main areas that the ČEZ nuclear power division has planned for this year for the Temelín Nuclear Power Plant. All this is aimed at two main goals. Ensuring safe operation and achieving a long-term average annual production from Czech nuclear power plants of 32 TWh, i.e. 2 TWh higher than before. “We reached an annual production of 32 TWh for both nuclear power plants for the first time last year. It will be a bit lower this year, among other things because we will have two shutdowns at Temelín instead of last year’s one. The key and priority are safety and efficiency of operation,” said Bohdan Zronek, member of the ČEZ board of directors and Chief of the Nuclear Energy Division.

Temelín Completes Transition to Longer Fuel Cycle

The plant’s engineers will also complete the transition to a longer fuel cycle this year. They have been gradually going over to it since 2023. The second unit will switch to a 16-month cycle between shutdowns in the spring and the first unit will do so in the autumn. “The cycle between shutdowns will therefore be half a year longer than the original design. This is a very important step in terms of the efficiency of the plant’s operation. The transition was naturally preceded by a thorough safety assessment,” emphasised Zronek.

The transition to longer cycles will allow the company to have a greater proportion of fresh fuel assemblies placed in the reactor. According to ČEZ’s management, the longer fuel cycle is one of the key components of the “32 Tera Safely” programme. It includes further improvements in safety, efficiency and the creation of conditions for the long-term operation of all Czech nuclear units. “By extending the fuel cycle, we will reduce the use of the plant’s lifetime due to shutdowns, and therefore cooling and heating of the units. We will also get higher production of almost two terawatt-hours per year for both nuclear plants. We completed the transition to a longer fuel cycle at Dukovany the year before last,” said Zronek.

Second Unit To Be Controlled by New System

The plant will continue to transition to a new control system from Westinghouse. Since last year, part of the new control system has been used by the first unit. In the first months of this year, the same modification will also be carried out on the second unit. The modernisation work, which began three years ago, will end in 2029. “The transition is gradual, taking place during shutdowns. Operators have been working in the new system environment since last year and it also controls about one third of the first unit’s equipment. The transition will be very similar in the second unit,” said Petr Měšťan, Director of Temelín Nuclear Power Plant.

In the autumn, engineers will convert another part of the first unit’s equipment to the new system. In addition to controlling the circulating cooling water pumps and the cooling of the spent fuel pools, the new system will also control most of the process systems in the plant’s nuclear part, such as the main circulating pumps, the primary circuit replenishment and discharge systems and a number of ventilation systems.

The challenging modernisation work has been underway since 2022. During the project, technicians have installed dozens of new servers, laid eighty kilometres of mostly fibre-optic cables, made modifications to the unit supervision room and replaced the process units in the control cabinets. The deployment itself was preceded by several months of testing. In total, the system controls thousands of devices, and tens of thousands of pieces of information pass through it every second.

Temelín Expands Use of Artificial Intelligence and Introduces Modern Control Methods

For the past two years, the power plant has been using artificial intelligence to reduce its own consumption. AI saves thousands of MWh of electricity annually. The plant will further strengthen the role of artificial intelligence in 2026. It is newly deploying advanced artificial intelligence models for work with documentation. This includes thousands of project, safety and operational documents. “Data is corporate gold. There is a huge amount of it in the nuclear power plant environment, a total of twelve kilometres of archive shelves at both plants. AI can make our work with this data much more efficient. We are already using it to work with documentation texts, and we want to gradually extend it to images, drawings and diagrams,” said Měšťan.

At both nuclear power plants, ČEZ is continuing to use drones to inspect hard-to-reach technology and to introduce state-of-the-art repair methods, such as laser cleaning and welding, advanced methods of applying metallic material (coldspray) and modern technologies for restoring piping. These procedures reduce intervention times and the need for shutdowns.

Temelín Expects Two Shutdowns This Year, the Power Company Will Hire a Hundred New People

After one shutdown last year, Temelín expects two this year. First, in mid-February, engineers will shut down the second unit for two months. In mid-October, the first unit will also suspend operations for approximately the same period. Each time it will be a standard shutdown for fuel changes, inspections and various upgrades. Temelín will complete the transition to a longer fuel cycle during the shutdowns. Experts will insert 66 new fuel assemblies into the reactor in both units and, in turn, seven containers with 133 used assemblies will be safely placed in the storage facility.

ČEZ plans to hire almost a hundred new people for Temelín this year as well. People with technical experience or education have a good chance. The power company is mainly interested in mechanical, electrical and materials engineers, but graduates of non-technical disciplines can also find employment. “In addition to a generational change, it is the large-scale modernisations that bring opportunities for new workers. In addition to operators and technical support staff, we are interested in, for example, technicians who will handle the planned investment projects and maintenance of the equipment,” added Měšťan.

Temelín Nuclear Power Plant employs 1,552 people. The number of women has been increasing over the long term. Currently, 212 of them work at Temelín.

 

Since the beginning of the year, the Temelín power plant has generated 0.7 terawatt hours of electricity. It and Dukovany are the sources that produce the largest amount of clean electricity and thus contribute significantly to ČEZ Group’s emission-free production. Nuclear power plants keep approximately twenty million tonnes of CO₂ out of the air each year.