Through UK Export Finance (UKEF) – the UK’s export credit agency – the government will provide a £192 million ($244m) loan guarantee.
This will enable UK-headquartered Urenco to supply Ukraine’s national nuclear company, Energoatom, with uranium enrichment services, which are vital for nuclear fuel.
On his visit to Ukraine, Mr Shapps also visited a children’s nursery attended by Nikita, the young son of the family he took in under the Homes for Ukraine scheme.
The Energy Secretary played a recorded message from Nikita for the children, the government said.
Ukraine and Russia conflict latest - in pictures
Mr Shapps also visited Kyiv, where he met with senior Ukrainian ministers and energy industry figures to discuss Ukraine’s recovery and continuing UK support.
And he also visited a power station undergoing repairs after being damaged by Russian bombing.
“Our support for Ukraine is unwavering in the face of (Russian President Vladimir) Putin’s barbaric invasion – the UK continues to stand with Ukraine as they repel Russian attacks and rebuild their country," Mr Shapps said.
“Being here on the ground, it’s truly remarkable witnessing first-hand the sheer courage, resolve and gritty determination of the Ukrainian people.
“Putin has used energy as a weapon of war: the action today to support nuclear fuel deliveries will help Ukraine end their reliance on Russian supplies and bolster their energy security.”