The group had gathered in a car park near to the Nottinghamshire coal fire power station when scores of police officers swooped arresting everyone and recovering items such as chains and bolt cutters.
The station, which has a total generation capacity of 2,000MW from four 500MW units produces enough electricity to meet the needs of approximately 2million people, twice the population of Nottinghamshire.
A police spokesman said: “We have gathered a large amount of evidence, which we’re now reviewing.
“From the information gathered we believe those arrested were planning a period of prolonged disruption to the safe running of the power station.”