• WC-135 Constant Phoenix was deployed to RAF Mildenhall in Britain last week 
  • Plane detects radiation from explosion in the air, used after Chernobyl disaster 
  • Comes after spike in the levels of radioactive Iodine-131 in Europe was detected
  • Radioactive particles have moved from Eastern Europe towards the UK 

By James Dunn and Dave Burke For Mailonline

A US Air Force ‘sniffer’ plane which took off from Sussex today was on a mission to find evidence of nuclear activity or explosion, according to strong rumours.

The WC-135 Constant Phoenix, which is specially modified to collect atmospheric samples, flew out of RAF Mildenhall on operational sorties.

The specialist equipment enables the crew to detect radioactive debris ‘clouds’ in real time is believed to be heading towards northern Europe and the Barents Sea.

News of the deployment comes amid claims Russia may be testing nuclear weapons, either to the east or in the arctic, after a spike in radioactivity was reported.

According to spotters a second ‘spy’ plane was also deployed from Mildenhall.

The WC-135 Constant Phoenix, which is known as a nuclear 'sniffer' plane, was deployed to Britain last week on an undisclosed mission (file image from a previous mission in 2011)

The WC-135 Constant Phoenix, which is known as a nuclear ‘sniffer’ plane, was deployed to Britain last week on an undisclosed mission (file image from a previous mission in 2011)

Air quality stations in Norway, Finland, Poland, Czech Republic, Germany, France and Spain have detected the presence of Iodine-131 at low levels

Air quality stations in Norway, Finland, Poland, Czech Republic, Germany, France and Spain have detected the presence of Iodine-131 at low levels

It is not the first time the Constant Phoenix has visited the British airbase, but the latest deployment reflects growing concern about an alleged spike in iodine levels recorded in northern Europe.

This has fuelled speculation that the WC-135 has been called in to investigate the cause of the higher-than-normal levels of Iodine-131.

Air quality stations across the continent detected traces of radioactive Iodine-131 in January and February, which seem to have come from eastern Europe.

The high levels of Iodine-131 has led some to suggest Putin is testing nuclear weapons in Novaya Zemlya near the Arctic.

The spike in Iodine-131 has sparked speculation that Russian president Vladimir Putin is testing nuclear weapons in Novaya Zemlya near the Arctic

The spike in Iodine-131 has sparked speculation that Russian president Vladimir Putin is testing nuclear weapons in Novaya Zemlya near the Arctic

However, the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organisation) ruled out a nuclear test had recently taken place.

Similar aircraft were used in the wake of the Chernobyl nuclear plant disaster in the Soviet Union in 1986 and the Fukushima incident in Japan six years ago by collecting particles and chemical substances in the atmosphere, days, weeks and months after they were dispersed.

The aircraft is equipped with external flow-through devices which collect particulates on filter paper and on board among its crew are special equipment operators from the Air Force Technical Applications Center.

On operational sorties like today’s from RAF Mildenhall the crew is normally minimized to pilots, navigator, and special equipment operators, to reduce radiation exposure to mission-essential personnel only.

In a statement on Monday, the CTBTO said: ‘If a nuclear test were to take place that releases I-131 it would also be expected to release many other radioactive isotopes.

Daily Mail