One of the two pieces of equipment for the Paks II NPP project – the core melt trap – has already been completed, and production of the reactor pressure vessel has now begun in St Petersburg, “which is a real milestone for the expansion of Paks” Hungarian Foreign and Trade Minister Péter Szijjártó told a press conference in Budapest. The melt trap had been completed ahead of schedule and would be delivered to Hungary in the summer, he added.

He said this certifies that the works are progressing on schedule with the Paks investment so that both new units can be connected to the network at the beginning of the next decade. He stressed that this would represent a huge step towards energy security for Hungary.

Specialists from Russia’s Atomstroyexport (ASE – part of Rosatom’s Engineering Division and general contractor) and officials from Paks II took part in acceptance checks for a core melt localisation device (melt trap) for the fifth unit at the Paks NPP (also known as Paks II unit 1) in March. The Paks II project was launched in 2014 by an inter-governmental agreement between Hungary and Russia for two VVER-1200 reactors (units 5&6) to be supplied by Rosatom.

The Hungarian Atomic Energy Authority issued the licence for the units in August 2022. The following December, the Hungarian parliament approved the extension of the life of the four existing VVER-440 power units at the Paks NPP for another 20 years. Paks currently provides half of all generated and one third of the consumed electricity in Hungary.

The 730-tonne melt trap will arrive at the Paks site by waterway. The VVER-1200 unit being built at Paks will be equipped with several passive safety systems. The melt trap is a special tank located under the reactor vessel and capable of containing the melted core in the event of a breach. It helps to reduce hydrogen production and the release of radioactive material into the environment. The vessel contains a fusion charge containing alumina and iron oxide, which when mixed with the core melt, reduces its specific heat.

The licensing and production of the melt trap required years of workand generated almost 35,000 pages of documentation. The documentation for the Hungarian Atomic Energy Authority amounted to 15,000 pages. This was checked by Paks II engineers at several sessions with the involvement of external experts before being made available to the authority. Vitaly Polyanin, the project director for Paks II, said the investment was moving forward on schedule.

Image: Production of reactor vessel for Paks II is currently underway in St Petersburg (courtesy of Strana Rosatom)