The patent, which has taken four years to clear, covers a fresh approach to stabilising and recovering radioactive sludge by mixing it with cement for long term storage.

Costain’s improved process enables the cementation of larger quantities of radioactive sludge, which is produced by spent fuel rods in storage ponds, more quickly and reliably than at present.

The proposed process could deliver a six-fold increase in the number of drums filled per week from two to twelve.

“We are extremely pleased to have been granted our first nuclear patent”, said Costain Paul Campbell, nuclear process sector director.

“This is one of a number of our novel approaches to the problems encountered when decommissioning nuclear plant.”

“This demonstrates the importance Costain places on developing innovative solutions to address complex challenges faced by the industry,” added Charles Sweeney, Costain Energy & Process Managing Director.