See what happened when a Greenpeace activist turned himself into a representative of Russian nuclear company Rosatom and participated in a gala dinner with the Finnish prime minister.

The Tsar Bomba our guy Dima speaks about in the video is the nickname for the AN602 hydrogen bomb, the most powerful nuclear weapon ever detonated. Its test on 30 October, 1961 remains the most powerful artificial explosion in human history.

What does this have to do with our campaign? Well, Rosatom and Russia are celebrating their 70-year nuclear journey. They have an exhibition of Russian nuclear technology in Moscow and the main piece on display there is a replica of this gigantic A-bomb.

So we built a replica of the Tsar Bomba that we call Fenno Bomba (Fennovoima is the name of the new nuclear plant that Rosatom is building in Finland). Then a team of our activists dressed up and took our Fenno Bomba in the very door step of a gala dinner organised by Fennovoima. There they gave leaflets and presented the Fenno Bomba to the guests (including the Finnish prime minister).

The gala was attended also by a "representative" of Russia's Rosatom. After the prime minister made his speech, the Russian wanted to say a few words. The rest is already a legend.

We wanted to highlight the absurdity of the fact that Finland is building a new nuclear plant with a Russian nuclear company Rosatom that displays a gigantic bomb as a proof of its nuclear know-how. 

Our action shows the farce of the Fennovoima nuclear project, but sadly the truth is even more unbelievable. The project is highly controversial, and has run into many problems before reaching the stage where it's still waiting for the building permit. Core issues include weak ownership, lack of financing and zero credibility, both in Fennovoima and its main business partner Rosatom.

Justin McKeating is a nuclear blogger for Greenpeace International, based in the UK.