Rendlesham Forest UFO – the radiation readings

In his book Open Skies, Closed Minds, Nick Pope described the radiation readings taken by Col. Halt’s team at the supposed UFO landing site in Rendlesham Forest as “the most tangible proof that something extraordinary happened there”. To justify such a claim, it is essential that the readings are shown to be beyond reproach.

My original conclusion, based on telephone discussions with the UK’s National Radiological Protection Board (NRPB), was that the figures reported in paragraph 2 of Col. Halt’s memo, from

Halt’s peak measurement of the radiation at the site was the bottom reading on the lowest range of the monitor

0.05 to 0.1 milliroentgens, were simply background levels of radiation. (As a technical aside, the correct units should have been milliroentgens per hour – the use of incorrect units seems to betray an unfamiliarity with radiation monitoring).

The subsequent release of Col. Halt’s real-time tape recording of events confirmed that the peak figure he quoted was simply a random burst, not a steady level. For much of the time scarcely anything was being picked up by the geiger counters – on the tape we hear them describing the readings at the site as “minor clicks”. Confirmation that this was only background radiation comes from the fact that the same levels were recorded over half a mile away from the supposed landing site, after they had crossed two fields beyond the forest (read the transcript here). The highest reading mentioned on the tape is “seven tenths”, i.e. 0.07; the 0.1 figure reported by Halt appears only in his memo and we do not know exactly where that reading was obtained, assuming it was not just a rough value recalled from memory.

Yet, as is clear from Nick Pope’s quotation above, my conclusion has not been universally accepted. Pope’s own researches led him to claim that the radiation levels recorded were 10 times higher than normal, and similar claims have been made by others.

Thanks to the influence and contacts of the British physicist Professor Frank Close the matter was resolved more definitively in 1997 for a television discussion programme produced by London Weekend Television (called Strange But True – Live) on which Professor Close and I were to appear along with Nick Pope and Col. Halt.

My earlier inquiries had shown that the radiation monitor used by Halt and his team would have been of the type known as an AN/PDR-27. On behalf of Frank Close, NRPB contacted the American manufacturers of the AN/PDR-27, who stated that Halt’s peak measurement of 0.1 mR/h was the “bottom reading on the lowest range” of the monitor and was “of little or no significance”. They noted further that these instruments are designed to be used to monitor workplace fields or radiation levels after sizable nuclear incidents and are therefore not suitable for environmental monitoring at background levels. On the basis of this information from the manufacturers, NRPB concluded that using such an instrument to establish a level of 10 times background is not credible.


	An AN-PDR27 meter of the type used by Halt et al, shown switched to its lowest range, which Halt referred to on his tape recording as the “Point Five scale”. The dial has five major divisions from 0.1 to 0.5 and each of these is subdivided into tenths. All the readings obtained were below 0.1 milliroentgens per hour. From http://www.alpharubicon.com/basicnbc/anpdr27ser.htm. For more about the AN/PDR-27 click here.

This, therefore, is the official view of NRPB and of the makers of the radiation monitor, which Frank Close publicly demonstrated to Nick Pope and millions of viewers on live TV on 1997 June 27. To confirm the matter I subsequently wrote to NRPB to ensure that there was no misunderstanding. In a letter to me dated 1997 July 7 Michael Clark of the NRPB stated: “We are convinced of the correctness of our interpretation.”

Nick Pope, however, had contacted not the NRPB but the Radiation Protection Services department of the UK government’s Defence Evaluation and Research Agency (DERA). Pope has described his inquiries as “the first and only official investigation into this aspect of the case”. [Now that the official Ministry of Defence file on the case has been released, we can see for ourselves the results of this “official investigation” – a handwritten memo amounting to fewer than 150 words.]

In his book, Nick does not say who it was that he spoke to at DERA Radiation Protection Services, but it was actually a man named Giles Cowling. When I tracked Cowling down, via his colleague Ron Brown, they sounded surprised that their opinion had been published in Nick’s book. Rather than regarding it as an ‘official investigation’ Cowling described his discussions with Nick Pope as a ‘private conversation’. Perhaps this is why Pope did not name his source or quote him directly.

When I presented Cowling with the above information from the NRPB, he wrote to me as follows on 1998 August 21:

“In my original discussions with Mr Pope I did indeed state that the readings were around 10 times normal background levels, provided that the instrument was appropriate for measuring background radiation (at the time of our discussions he could not state what the instrument was), calibrated and being used/interpreted correctly. I share the NRPB view that the use of a high-range survey instruments to measure (accurately) environmental levels of radiation is somewhat questionable and this must throw some doubt on the validity of the data reported.”

Cowling also confirmed to me by telephone in 1998 August that Nick Pope had not re-checked the facts with him. This was over a year after Professor Close’s TV demonstration that there was nothing significant about the radiation levels at Rendlesham – an opinion with which Cowling, Pope’s own source, now agrees. (See also 2009 Update, below.)

In 2003, as part of a TV documentary about the Rendlesham case, the Sci Fi Channel made their own check on radiation levels at the site in the hope that, had the area genuinely been contaminated with unusually high levels of radiation, some traces might remain. (Of course, it has never been established why an alien craft should be leaking radiation, or what sort of radiation was involved*.) The readings were taken for them by Patrick Davison, an environmental scientist from Mayer Environmental Ltd of Brentford, west London. The Sci Fi Channel’s programme itself was non-commital about the results, but Davison confirmed to me by telephone in 2006 March that he found nothing above background at the site.

If Nick Pope or anyone else is going to continue to use the radiation readings as “tangible proof that something extraordinary happened there” then they are on very shaky ground indeed.

In a pro-UFO TV programme first broadcast in 2009 called I Know What I Saw, Pope was interviewed about the radiation readings at Rendlesham. In this interview, Pope did not rely on his now-discredited ‘investigation’ discussed above but showed instead this internal memo from the Ministry of Defence files which says in part: “The value of 0.1 milliroentgens (mr) ... seems significantly higher than the average background of about 0.015 mr.” In the TV interview, a clip of which can be seen here, Pope described the memo as “One of the most important documents to emerge from the MoD’s case files... absolute proof positive that something extraordinary happened”.

The MoD files make it clear that they never undertook any investigation into the radiation levels at Rendlesham so they never established the truth about the readings reported by Halt. The opinion in the MoD memo was based on the same assumptions as Pope’s own cursory ‘investigation’, namely that the figure quoted by Halt was a steady level and taken with an appropriate instrument. As we have seen, both these assumptions are incorrect – it was a random peak recorded by a meter designed to measure much higher levels of radiation. Hence the opinon quoted by Pope is no ‘proof’ at all and would doubtless have been withdrawn had the MoD established the full facts laid out above.

* Many current spacecraft use radioisotope thermoelectric generators (RTGs) to generate electricity. These use fuel with a half life of many decades, usually plutonium 238. Any spillage from such a device would be detectable for many years afterwards. Nuclear reactors of the type used in terrestrial power stations use fuel with a half life of thousands of years, and radiation due to a leakage from such a reactor would still be detectable today.