"Hot" instruments – clear guidance on buying from abroad.

I suppose it all comes down to trying to establish the ‘actual’ risk versus the ‘theoretical’ risk and what level we as individuals and officials are willing to accept. For instance everybody knows that UV in sunlight can cause melanomas, some people take the risk seriously and apply various precautions, others view the risk as less and take no precautions, similar with smoking.
A few years ago I visited the Nevada Test Site and was able to go to the Sedan Crater, it would be easy to assume that standing in the crater of a nuclear explosion would be very bad for your health but there was a sign there that said something like ‘You would have to stand here for 4 years to receive the same amount of radiation as a normal X-ray’

Sedan Crater http://en.wikipedia.org/wiki/Sedan_Crater

Shielding for 226Ra dials on WWII Instruments

If we assume that the radium paint in luminescent dials is in “secular equilibrium”, a state where all of the daughter isotopes are in balance W.R.T. their natural production and decay processes, the average gamma energy emitted is around 830 keV.

To shield this level of gamma activity one commonly uses a term, “Half Value Thickness” (HVT); that is the amount of a material that will reduce the measured activity by one half. Similarly, there is the unit, TVT, tenth value thickness or the amount required to reduce incidence activity by 90%, down to 10% of initial levels. For 226Ra, the HVL of lead is about 14mm (0.55”) and the TVT, 42mm (1.65”).

I guess that’s the bad news. The good news is that one can theoretically still allow something like a panel to be safely viewed behind special “leaded glass”. The bad news is that to shield down to a socially acceptable level (open for argument) of, say, 10% initial, the thickness of the leaded-glass required would prohibit it from being done, both from a weight perspective as well as a cost which I would suggest be in the many thousands of dollars (or pounds).

Bottom line, using small amounts of lead will help to reduce the gamma emissions from a luminescent dial but not sufficiently to prevent it from being detected by either the Postal or Courier system where sensitive gamma detection equipment may be utilized. And it’s only going to get worse. Major International ports and border crossings are starting to incorporate a new generation of detectors using muon tomography and GEM detectors. Basically, it won’t matter how much shielding you incorporate, a radioactive source inside a package will still be detected. Thanks (I guess) Homeland Security.

As I see it, the only way around this for panel-builders and instrument collectors is going to be to reach some agreement with the Nuclear Protection folk in conjunction with the shipping industry.

I’m not an expert. Once again, a caveat that my data may be out of date or incorrect as I haven’t double checked this with colleagues.

Wayne Logus

Hi P&P:
Wow, lots of really good and very pertinent questions. One could write a chapter on each and still not cover everything adequately. I won’t even tackle the specific questions now.
It seems to me we have a complex dynamic that consists of 1) Theory, 2) Health Protection rules and regulations and 3) Real world situations. The boundaries between these variables are blurred and everyone is going to have a different opinion on which to emphasize. This thread may not be the ideal form to discuss this in detail; it’s a bit of a tangent from the initial query by OneEightBit.
Perhaps the most important thing that readers can take from this whole discussion is that it’s not a black and white issue. It certainly won’t hurt to increase ones theoretical knowledge about Radium and radioactivity, nor become more familiar with existing rules and laws governing what is legal vs. what might be tolerated. I am unaware of what discussions regarding radium instruments, displays, aircraft in museums, etc. have gone one with the IRR99 in Britain, the CNSC in Canada or the equivalents in other Countries. It has to be, in part, a lack of manpower and priorities with the Regulating Agencies, that regulations and guidelines in the strictest sense of the word, haven’t been enforced. It is my understanding that some are trying to work within the system to create an acceptable and legal way of shipping instruments with radium painted dials but it is anyone’s guess when, if ever, a compromise might be reached.
I’ve attached a well-known chart , thanks John, on the decay scheme of 238U (from whence Ra is extracted and purified) to help explain why the problem goes beyond just “Radium”. Of course, our gauges only have isotopes “downstream” from Radium. We know that one of the decay products is 222Rn, a gas, which decays giving off a nasty alpha particle (bad for lung tissue and perhaps the 2nd leading cause of lung cancer outside of smoking). jb154 has pointed out that even the outer bags housing radium gauges become contaminated after time. Radon, a natural material found in many soils, in turn decays to a whack of other isotopes. 214Bismuth, in particular, has isotopes with very high gamma energies (600 keV to about 2.5 MeV) which can plow through a lot of material before they are stopped. An eighth inch of lead will reduce the gamma radiation from these higher energy particles but not even by half.
When Radon undergoes decay, some can escape and the daughter isotopes can end up some distance from the “sealed” gauge. Basically, surfaces will eventually pick up some radioactive component depending on the distance from the gauge or panel. That means the glass cover, the body of the gauge, the bag, the box, the walls of the room, etc. If you store a radium dialed instrument in a room for a long time, you will be able to detect residual activity on materials in that room long after the instrument is removed. Is it significant? Do we need to worry about it? There is no absolute “right” answer; it’s statistical, but less is better in this case. That’s a whole new discussion.

My apologies to those who already know all of this and for any theoretical errors I’ve made or incorrect explanations. Rephrasing or edits are welcome.

Thank you

[QUOTE=zorgon;2097952]I thought it would be prudent to take a closer look at a representative sample of early WWII Allied instruments with radium-painted dials and obtain some actual measurements.

Brilliant, encouraging, post of the year award ! A lot of effort generously shared.

While I get my head around all this, apart from not opening gauges, are there some quick simple storage tips to minimise potential human harm ?

1. Store in ventilated room to allow daughter product radon gas to escape.
2. Store away from children and pets – do not open gauges.
3. Allow minimum 1 metre barrier between display and people.
4. If disposing, dispose off to museum with a system in place to responsibly handle radioactive gauges.
5. Minimise time exposure to displays – how many hours per month ?

Is there a better mechanism than ebay for the transfer of gauges between collectors ? Is it responsible, in the light of the growing awareness of this issue, for participants in historical aviation to allow, by passivity, an industrial contamination tragedy to evolve ? This is not radium per se, but (a) the opening of antique gauges with oxidised paint binders resulting in the inhalation or ingestion of unstable radioactive substances (b) bulk storage of gauges in unventilated rooms allowing radon gas buildup, (c) something else ? Maybe a trading platform should be set up for gauges that integrates postal arrangements, end of life disposal, instrument lists, material safety data sheets, contacts for disposal.

Given the diffusion of daughter elements into other materials, does this mean that a bakelite instrument case or gauge mechanism behind the dial face is, after 70 odd years, radioactive ?

For Dummies (me), what are the types of radiation – beta, gamma etc, which radiation is the common cold radiation and which is Ebola radiation ?

For storage of bulk lots of gauges, are there materials that will absorb some types of radiation better than others, eg a display case with PVC sheet, plexiglass sheet or glass, a bulk store surrounded by brick (old oven lined with refractory bricks ? ), steel (old safe), water (water filled plastic barriers), or air, ie 1 metre + exclusion zone around shelf to allow radiation to dissipate.

For Dummies, radiation context. Eg I understand that when I fly in a plane, I receive a dose of cosmic radiation far in excess of terrestrial background radiation. If a pilot or cabin staff on the plane are therefore exposed to cosmic radiation on a daily basis, and 100 odd years of flight have not identified that these worksites exposed to cosmic radiation significantly increase medical issues for aviation workers in comparison to the general population, are my display of unopened gauges reasonably safe in this context ?

Wayne could you make a high resolution immage of the spectra available either on the forum or by direct pm.
I have a small decal labeled “AIR” running 200CPS on an NE BP4 mainly beta.
This in double Zip lock bags!!!
After 18 months a check of the carrier bag outer containment’s inner surface revealed counts in region of 18 to 25 CPS. In the 222Rn ROI
Single radon atoms can and will difuse
most any place it seems. A little look into aerosol physics explains the issue

Wayne.
A truely excelent piece of work. Are all the instruments tested exhibiting the same spectrum in terms of the energy of photo peaks.
This could prove a valuble reference for those of us with PZT detectors which may have enough resolution to make sence of those HPGE spectra which I asume they are.
The big problem is the 222Rn that by difusion and atachment takes the daughters everywhere.
Thanks the neatest bit of work yet

Hi Wayne
Thanks for going to the effort of getting the gauges properly analysed and writing your findings here.
Regards Paul

Wayne

Thank you very much for taking the time to conduct such a comprehensive study and posting the results here.

Cheers

Michael

Analysis of WWII Instruments with radium painted dials

I thought it would be prudent to take a closer look at a representative sample of early WWII Allied instruments with radium-painted dials and obtain some actual measurements. The two aspects investigated and reported here are the isotope of radioactive material used on the dials and the maximum dose rate emitted from the units (i.e., the source of the radioactivity and its magnitude).

The gauges and instruments investigated were:

# Description, Stores Ref #, Version, Year, Dose rate at contact (mR/hr)
1, Altimeter, 6A/1203, Mk XIVB, 1941, 4.8
2, RPM Indicator, 6A/1203, Mk IVB, 1940, 2.5
3, Rate of Climb, 6A/942, Mk IB, 1941, 3.5
4, Boost, 6A/16581, Mk IIIM*, 1943, 1.9
5, Oil Pressure, 6A/570, No XIE, 1943, 3.8
6, Compass (RCAF), 6A/0.726, P8, 1944, 1.6

( 1 mR/hr = 10 micro Sv/hr)

A calibrated Keithley survey meter (Model 36100) was used to measure the radiation dose from the instruments. At 1 metre the dose rate from each instrument was equal or less than ~0.1 mR/hr but this is still a significant level and many times above background. The dose rates on contact with the glass dial faces are listed in the table above. The younger generation will want to convert these to the current SI units of µSv/hr or mSv/hr. As mentioned by others, even a single unshielded instrument will stand a high likelihood of being detected by the newer International mail and courier transportation monitoring systems.

~~~~~~~~~~
To determine the isotope(s) of radioactive material used in the dial paint I went to the University of Alberta SLOWPOKE Nuclear Reactor Facility. The reactor is used as a source of neutrons for elemental analysis via neutron activation analysis (NAA), and for radionuclide production, research, and teaching. The Facility has several high resolution, highly sensitive gamma-ray spectrometers used to analyse radioactive materials derived from many different sources. The SLOWPOKE Director, Dr. John Duke, performed all the measurements and my thanks to him for his time and comprehensive explanations. The hyper-pure germanium detector of the gamma spectrometer we used was of modern design and the associated PC-based multichannel analyzer (MCA) operating software by APTEC was used to collect and identify the radionuclides present in the various cockpit instruments. The Facility frequently analyzes Naturally Occurring Radioactive Material (NORM) from the 238U and 232 Thorium decay series, and has on hand numerous reference standards to confirm the spectrometer energy and efficiency calibration.

Radium-226 (half-life = 1600 yrs.) is itself a decay product of 238U the most abundant isotope of uranium. Because of its long half-life and differing chemical behaviour Ra can readily be separated from its U source. Radium-226 has numerous “daughter” products (other isotopes, radioactive themselves, that are created when the radioactive ‘parent’ decays). Examples of 226Ra decay products include gaseous 222Rn, and gamma-emitting 214Pb and 214Bi. In addition to 226Ra emitting a characteristic gamma-ray of its own gamma-rays emitted by the latter two radionuclides in particular serve to “fingerprint” or confirm the presence of the long-lived 226Ra to which they owe their existence.

Results and Conclusion. As suspected and confirmed by others on this topic in past articles and for example the clean-up at RAF Carlisle in the 90’s, the only long-lived radioisotope found in any of the instrument dials examined was 226Ra (together with its short-lived progeny). Based on the absence of any gamma-emitting daughter products of 228Ra it is safe to say that there was absolutely no evidence of 228Ra being used in any of the instruments analyzed.

An image of the display of a spectrum from one of the instruments tested is attached. Basically, all units tested had identical spectra (in regards to the gamma-ray photopeaks present). In all instances 226Ra was confirmed as the source of the radioactivity in the instruments, as evidenced by its gamma-ray photopeak at 186 keV together with the numerous gamma-ray photopeaks from its gamma emitting decay products 214Pb and 214Bi. Of note was the complete absence of the gamma-ray photopeaks at 583 and 911 keV from 228Ac, the immediate daughter product of 228Ra, confirming the absence of 228Ra in these instruments.

My personal feeling is that we should treat the instruments with respect, limit the time we are in close proximity to them, keep them stored in areas which are ventilated and not adjacent to where people spend long periods of time, i.e., where they live or work. We need not eliminate them from properly controlled displays and personal collections if we adhere to the principle of ALARA (As Low As Reasonably Achievable). In addition, it would be prudent that one never open the units and risk contamination of themselves or the immediate environment. Special care must be given to units that are damaged, where the glass is missing or broken, or when there is a chance that remnants of the dial paint can escape the enclosure. Using gloves, the units should be sealed in Ziplock bags and disposed of in a safe manner which is yet to be universally determined.

Wayne Logus

[ATTACH=CONFIG]223839[/ATTACH][ATTACH=CONFIG]223840[/ATTACH]

One thing I did notice when I had all my collection in one room was that there was a distinct lack of spiders, usually these little creatures make a home in the corners of the room ceiling and leave webs to collect dust but there wasn’t any in that room! There was no dead ones in the room either so maybe they kept their distance.

I’m not sure whether I’ve seen the following item (from 2002) before but it contains some interesting comments re timepieces and the aviation sector http://www.hse.gov.uk/radiation/rpnews/rpa21.htm#a11

Possibly pre-exemption!

I believe there is an exemption for clocks and watches, yes.

My understanding as referenced back in 2010 under post #25 in here http://forum.keypublishing.co.uk/showthread.php?t=97355&highlight=health was – “… is that previously exempt ‘sectors’ might also be coming under the spotlight again.”

I’m not certain whether that has happened

With reference to Rocketeers comment of : My pet hate is going to AJs and seeing dodgy gauges with no glasses on them and flakey paint. I have been told to f’off a few times when I suggest to the sellers that they remove them.

Yes I have been there too! Stick your hand in the box with lots of dodgy gauges with open faces and flaking paint then go and treat yourself to the obligatory bacon sandwich or burger yum!That would be one way to zap those stomach bugs. I have been to some events or AJ’s in the past that actually screen the instruments prior to sale or even customers going around stalls with their own Geiger counters often receiving curt replies! Hey ho even after buying a bag full of WW1 instruments you could always get run over after leaving an aero jumble! Who knows what ‘s risky and what’s not!

I believe there is an exemption for clocks and watches, yes.

The hand held Geiger counters are good, I have used them when visiting the former eastern block states when buying fruits in the market to measure the radio active readings prior to purchasing. All depends where they have been grown and what weather fall out they have been exposed too dependant on wind direction and rain etc, the bottom line is radioactivity is every where but you can take measures to reduce your exposure. I read somewhere on a previous forum that pets around the house are more susceptible to exposure as they are smaller creatures and cannot take higher doses that humans can, Anyone got any dogs or cats that sleep next to the instrument panels or have a dial hanging off their collar? Anyhow all food for thought , could be an old wives tale but who can say for sure? Is it legal to sell these instruments on ebay? There must be some clause or exemption somewhere for collectors or traders as these luminous radium dials also appeared on wrist watches, therefore jewellers must be able sell them.

Vote 1 jb154

[QUOTE=jb154;2096219]Hi
Further thoughts on radio luminescent instruments ingrouth

jb154,

Not a long time ago you could write on a coupon on the back of a comic and get a Phantom ring delivered in the post that glowed in the dark. Probably stuck in the lower gastro intestinal tract of some adults are some of these radium infused rings, probably in the grumpy adults, lots of them. So this stuff is out there doing damage. There is also a former factory in my city that used to paint radium aviation dials, that is now a swank apartment, so there are a lot of permutations of surprise and misery waiting to unfold. I guess if you have the power to lessen misery in the human condition that puts you on the side of the angels. Maybe we are at the early edge of something that will grow in importance.

You seem to know a lot. Therefore I vote you convenor of the first multinational taskforce for radium in aviation gauges. This means that in a few years time you will get a free cup of instant coffee at the first Conference of Radium in Aviation gauges, to be held wherever there might be a budget motel and cheap alcohol. In the meantime you can assist in drawing up a fact sheet that in simple language explains the risks and risk management strategies around historic aviation gauges. This would be an example of ‘self regulation’ for historical aviation, in anticipation of external regulation, a matter of ‘when’. If folk want to cut and paste it and stick it in a museum foyer then that might help anyone having Grandpa’s altimeter on the mantlepiece.

There is no better place to start this fact sheet than this forum. A fact sheet will assist newcomers to manage an avoidable risk, old timers to manage what may be unfounded fears and historical aviation from losing artifacts confiscated in a blanket response to ‘an event’.

Tonight I will open a bottle of whiskey and packet of cigarettes and have a crack at a draft, which I would welcome being edited as per wikipedia. There are a lot of questions that I have that I would love you to answer. You will have to speak slowly because I am partially industrially deaf and sometimes push my face into a glass door that says pull. If you end up saving one five year old from chewing on the edge of a radium gauge left accessible through ignorance then you are a shining diamond, a stable and fine form of carbon indeed.

updates off the net

What you all need is “bionerd23”, a seemingly fearless (brainless) Rinemaiden.
She knows her stuff though, well mostly and has access to some sweet kit.
Relighs mainly on a Gamna Scout circa $500 with shiping + customs + handling +VAT Yer right. Nice bit of kit though an
a/b/g meter calibrated in cps uSv and mSv she apears to be a student so it cant be that costly WRONG.
There is a google group— geiger counter enthusiasts— mainly American also a neutron sub group yes they seem quite keen to generate neutrons, all in the interest of science you understand mmmm. Well takes all sorts.
Its all out there on the web.
Check out the bionerd23 she is not a little irespincible but there is some good info in there if you can follow her anticks.
USA still have Victoreen CD V 700 with a thin wall beta gamna GM tube. $220 at yer door, HMRC & GPO permitting
It displays cps & mR/hour BUT we in europe use SI units Grays & Siverts [more complication lots more]. The R stands for Roentgen a legasy unit not directly equivalent to the SI unit.
See wiki cut and paste below.
Kerma is energy dumped in a mass of air.
Roughly 100R = 0.877 Grey its a smaller unit..

[3]*One roentgen of air*kerma*deposits 0.00877*gray*(0.877*rad) of*absorbed dose*in dry air, or 0.0096 gray (0.96 rad) in soft tissue.[4]*One roentgen (air kerma) of X-rays may deposit anywhere from 0.01 to more than 0.04 gray (1 to 4 rad) in bone depending on the beam energy.[5]*This tissue-dependent conversion from kerma to absorbed dose is called the*F-factor*in radiotherapy contexts. The conversion depends on the ionizing energy of a reference medium, which is ambiguous in the latest NIST definition. Even where the reference medium is fully defined, the ionizing energy of the calibration and target mediums are often not precisely known.
Confused yet It gets me every time.
Big mug of black coffe dont aproach after 10 in the morning or you melt your brain.
Ballpark divide mR by 115 to get Grey for beta/gamna Grey = Siverts.
There are some eastern block instruments ib SI units the bionerd23 features some.
I have never used any no idea on price either. Try Google.
You are prob looking at a “pancake” tube GM counter with a beta filter lump of ally across tube window
Bout it really
Just simple common sence and a suitable counter. I live near Farnborough and for traveling expenses would come and frisk stuff say S of Oxford and E of Sailsbury.
We need like minded experts spread across the UK to provide a service to collectors.
Now there’s a thought.

This is such a thorny subject and liable to invoke strong feelings.

My last panic (sadly, the correct word) resulted in me disposing of most of my instruments, all with the pre-requisite health warning. This is partly why I make replica instruments.
Recently, I have been buying post war non radioactive gauges (that utilise the same cases as WW2 instruments) and popping my faces into them. The Whirlwind panel will use a full set of replica gauges.

My pet hate is going to AJs and seeing dodgy gauges with no glasses on them and flakey paint. I have been told to f’off a few times when I suggest to the sellers that they remove them.

Before I sold off my collection, I measured the activity of them all. A few points:

1. Generally, the older the instruments, the worse the radiation – WW1 German were scary.
2. Seemingly identical gauges had very different readings. It was not always the case that the more ‘browny white’ paint the higher the reading.
3. WW2 German instruments generally had low readings.
4. Sometimes, exposed radium is used. For example, on switches, throttles etc. Off white paint can be the giveaway.
5. Russian/Soviet Jets into the early 70s used liberal exposed radium. I once saw Mig21 throttles with a ring of the stuff around the handle.
6. Thick glass is good. Dust is dodgy.
7. A crash site face, even devoid of paint, can have elevated readings.

I do wish I had known more about this when I was a kid. I used to pull instruments apart and blow the dust away, not knowing the dangers. That was over 30 years ago. I also slept between a Spitfire and a Hurricane instrument panel and was fascinated by the illumination provided by both. I am now 48 and feel that I am ‘not out of the trees’. I try not to dwell on this and the likely damage I have done.

I am not an expert by any means, but do be careful.

You don’t know unless the instrument is calibrated and you sort out if you are reading G+B or just G

oops

Hi
Further thoughts on radio luminescent instruments ingrouth
Secular equilibrium (s.e.)
Radium abundance
Ingrouth
Given daughters are much shorter lived than progenitor
It can be generally said that after 5 half lives of of longest lived daughter the whole series decaying at the same rate as progenitor.
In time activity increases. All daughters in s.e. so there is greater activity with time.
Ra abu dance
Whatever the isotopic mix of the original Ra 226 from the 238U series will be all that,s left

Re setting up to decontam.
The inevitable on site activity will require you to be licensed under Radio Active Substances Act 93 And follow the procs. set out in IRR99. RSA93 has updates as well 2001
I have heard Amasham International charge up to£1000 ea for disposal.
For Gods sake nobody do anything stupid to raise the issue above the radar, NRPB & Environment Agency seem content at the moment lets keep it that way.

Oh DO NOT screen with a sheet of lead use 10mm ally or 25mm plexiglass.
Any high atomic weight screen will stop the beta radiation,of which there is a fair amount, dead liberating Bremsstrahlung X rays.
see its complicated again.

There is no good cheap monitor.
Remember the issue is contamination spread not how long have I got to live!!! You will need at least a beta monitor. As an example a bloody great chunk of thoriated mag alloy gives us 25 uSiverts gamma. Same thing chucking out 200 counts per second beta. Hard to miss!!! Smaller quantities the gamma will sink into the background.
Clearing up one point for some but not all.
Gamma & X rays are em radiation like light IR radio and cosmic rays. They can make it through a house brick if energetic enough no trouble.
Alpha and beta rays arn’t they are particles helium nucleii and electrons simply in a hurry.
Alpha go max 10mm in air Beta max 1m in air. again energy dependent.
To detect Alpha requires special kit best take swabs and place in vacuum chamber to count complicated again
with beta particles most end window GM tubes will detect beta likewise end window scintillation devices.
A cheep and chearfull GM device will not show up contamination adequately.
Leave it all well alone unless you are in the industry and can manage the risk. If you were you wouldn’t any way would you? One good size compass is intermediate level waste so you would contravene RSA99 and be in doo doo if caught.
jb154

edited on laptop 16:01 15/12/13