Parts of Cumbria are still suffering from radioactive contamination 20 years after the Chernobyl disaster.
Sheep have to be tested for levels of Caesium-137
Safety restrictions were placed on hundreds of farms amid fears contamination would travel up the food chain via grazing animals.
After the disaster background radiation in Cumbria was 10 times normal levels.
Restrictions were subsequently lifted, but sheep on nine farms are still undergoing radioactivity checks before they can be sold for human consumption.
Alistair Mackintosh, the National Farmers' Union (NFU) former county chairman said that farmers felt the impact soon after the disaster.
"I remember initially that we were put in a total movement ban, which was only supposed to be for two weeks, but was stretched to five months.
A reactor at the Chernobyl plant blew up on 26 April 1986
"You take any business that can't sell its product for that time and it has quite a financial effect."
Now it is only on nine farms that sheep have to be tested for levels of Caesium-137 prior to being sold.
Farmer David Ellwood said that they do not always pass the test immediately.
"If they are monitored straight after they have come down from the fells there tends to be high readings, especially in summer with the fresh grass coming up.
"They are then brought in for a fortnight or three weeks and it passes through them and they are OK."
Farmers receive a £1.30 payment towards the cost of testing each sheep.
Mr Ellwood added: "It is a lot of hassle but it has gone on so long we are quite used to it."