The UK joined other countries in contributing to a nuclear safety fund for the site of the 1986 Chernobyl disaster.
Marking the 25th anniversary of the accident that happened in what is now the Ukraine, the UK donated £28.5m to the European Bank for Reconstruction and Development-managed international funds.
Energy Minister Charles Hendry said: “The funding we are pledging today will go some way to international efforts to ensure the permanent safety and stability of the Chernobyl site, to prevent it from posing any further hazard to health and the environment.”
According to the Department of Energy and Climate Change, the UK has given over £71m in previous rounds.
The money will help with the construction of a 257 metre-wide and 105 metre-high steel arch over the damaged Reactor and a facility to safely and securely store spent nuclear fuel.