Strategy developed for the dismantling of the reactor’s complex technological equipment

The Ignalina Nuclear Power Plant (INPP) is currently starting one of the most complex dismantling works, with the completion of the first stage of the project involving the dismantling of the reactor technological equipment – steam-drum separators. The result of this stage is the developed dismantling strategy, which ensures a safe and smooth further workflow.

“The main function of the steam drum separators with metal cylinders almost 3 meters in diameter and more than 30 meters in length, was to separate the steam and water mixture from the reactor’s technological channels into steam and water, producing dry saturated steam at the outlet. Steam from the steam drum separator was directed to the turbines for power generation, and the separated water was returned to the suction collectors of the main circulation pumps for multiple circulation. This engineering solution was not only important as a part of the reactor, but also extremely complex in its own construction, so that we have about 6,000 tonnes of radiation-contaminated metal belonging to different classes of contamination, which cannot simply be removed, cut off or disposed of as scrap metal,” says Jonas Kimontas, the Head of the Project Management Department.

These strategic preparatory works are implemented by the INPP together with international partners and under the supervision of an independent FIDIC Engineer, which allows to ensure maximum quality, application of the latest technological solutions and expert supervision of project management. “The main document prepared in the first stage is the strategy for the dismantling of the steam drum separators. The dismantling processes, procedures and tools defined in this document form the basis for the planning and execution of the works,” notes J. Kimontas.

The dismantling strategy document consists of several parts, including analysis of the dismantling feasibility, working methods, techniques and equipment, occupational safety, waste management strategy, radioactive contamination containment, logistics, etc. Additional documents defining emergency preparedness and civil protection, environmental and social aspects were also accepted by both the INPP and the FIDIC Engineer within the timeframe foreseen in the contract.

According to J. Kimontas, this is one of the most complex dismantling works to be carried out by the INPP, therefore the long-term experience of the international partners in various similar projects related to nuclear power facilities is particularly important and will be one of the factors contributing to the successful achievement of the joint goals of the project.

The above-mentioned works of the first stage have been carried out in accordance with the service contract signed at the beginning of July 2024 with the Swedish-Spanish consortium, consisting of Westinghouse Electric Sweden AB (the leading partner) and Westinghouse Electric Spain, S.A.U., for a total amount of 32.4 million euros. The contract is planned to be implemented in 6 years.

The scope of the implemented project includes the preparation of a technological design for the dismantling of 8 steam drum separators and associated systems (metal structures, piping, thermal protection, etc.), including a safety analysis, the design of the necessary dismantling equipment, and the dismantling, fragmentation and transportation of the drum separators to the pre-treatment sites.

It should be noted that the project of the steam drum separators dismantling is related to another important decommissioning project – the nuclear power plant reactors dismantling. The works are planned to be carried out in the controlled radiation contamination area of the INPP, where special requirements are applied to ensure radiation safety.

The project is funded by the International Ignalina Decommissioning Support Fund administered by the European Bank for Reconstruction and Development (EBRD).

Today, one of the main objectives of the INPP is to carry out the works for the immediate dismantling of the decommissioned nuclear power plant without leaving an unreasonable burden of radioactive waste management to future generations. The mission of the company is to create a clean environment through the sustainable management of the legacy of nuclear activities. After the final completion of the operation and dismantling of the power plant, it is planned to build and operate a deep geological repository up to 2079, and during this period to establish itself as an advanced new generation company and successfully develop its activities further.