Radioactive Particles found on Beach.

[paul_b]

To address your points in order:

Generic geiger counters are among the cheapest radiation monitoring instruments going, as they're comparably simple devices. From what I do know about the 1957 incident, a lot of the health physics had to be derived very quickly after the accident happened - they used the equipment they had to deal with the problem they faced. My point, Pete, was your leap of faith about detecting plutonium. It's not that easy to detect alpha emitters in the environment, you would look for something else. Power stations and Sellafield still do discharge amounts of radioactivity to the environment, including the easy to detect Cs137. That is more likely to show up with the sort of device you say you are using. Some isotopes of plutonium have similar half lives to Cs137, and uranium is present at the parts per million level in just about everything anyway. Incidentally, most of the uranium in the Irish Sea came from the phospate plant at Whithaven....

X-rays are not necessarily lower in energy than gamma rays. Please check this one somewhere else if you don't believe me. It's the method of generation which determines what the photon is called. If you belive it is defined by energy, can you tell me at what energy you would start to call and X-ray a gamma ray instead please? Depending on the energy response of your detectors, and what you intend to use them for, they may have additional detector tubes on to enhance sensitivity at lower energies. Detection below 5keV gets quite tricky, and most manufacturers I've dealt with won't quote a response below 10keV for their standard tubes.

Yes, I was patronising. I was brought up in West Cumbria, and have heard all the legends..... There's several "other interest" groups operating nationally and locally within Cumbria. It's a free country and people can make up their own minds, but I'd rather deal in fact than with propaganda, or what some friends of someone told them. I wouldn't normally take a radiation monitor to the beach with me, so the suggestion that contacts of yours did so indicates they were looking for something anyway and may have had a point to prove?

I'm interested that even though the Irish Sea has a low tidal turnover, there still isn't any untoward radioactivity on the Wirral coast... Can't be all that bad then?

I really didn't want to get into the nuclear debate, so I'll probably shut up now, though if you really want to know more about radiation (I had thought this was a swimming forum), do let me know.

Cheers,

Paul.

[Wildswimmer]

Originally Posted by paul_b

To address your points in order:

Generic geiger counters are among the cheapest radiation monitoring instruments going, as they're comparably simple devices. From what I do know about the 1957 incident, a lot of the health physics had to be derived very quickly after the accident happened - they used the equipment they had to deal with the problem they faced.

I suspect that the Geiger counter was the only type of equipment available in 1957. Bear in mind that the nuclear industry was very young at the time.

Originally Posted by paul_b

X-rays are not necessarily lower in energy than gamma rays. Please check this one somewhere else if you don't believe me. It's the method of generation which determines what the photon is called. If you belive it is defined by energy, can you tell me at what energy you would start to call and X-ray a gamma ray instead please?

I must have been taught a different physics curriculum to yours, bearing in mind that "my" physics was that taught during the 1950/60s. While I'm aware of wave/particle duality the only definition of EM radiation that I've ever "thought in" is as a wave, with energy inversely proportional to wavelength. To reply to your last point, at which point does infra-red become red, or violet ultraviolet? Answer: at no defined point.

Originally Posted by paul_b

Depending on the energy response of your detectors, and what you intend to use them for, they may have additional detector tubes on to enhance sensitivity at lower energies. Detection below 5keV gets quite tricky, and most manufacturers I've dealt with won't quote a response below 10keV for their standard tubes.

The x-ray tubes in both of my Russian instruments are claimed to detect 30keV upwards - just above the energy that can be radiated from a colour TV CRT running on 25kV and any biological effects of exposure to low-level X-rays below 30keV seem now to be generally regarded insignificant (although I wouldn't).

I've just had a look at another old ex-MOD instrument that I have (Indicator Radiac Mk2) that came with its three sensors, X-ray, gamma, (which are GM tubes) and beta/alpha which judging by its large aluminium foil window I suspect is an ionisation chamber. The readout is in counts per second so I suspect has been designed for use post nuclear attack where actual radiation dose would have been determined from a book of tables. The circuitry in both this instrument and my "Indicator, Contamination No1" (as used post Windscale) is all valved - not a transistor in sight. I also have another radiac but this is ionisation so useless for any survey work.

Originally Posted by paul_b

Yes, I was patronising. I was brought up in West Cumbria, and have heard all the legends..... There's several "other interest" groups operating nationally and locally within Cumbria. It's a free country and people can make up their own minds, but I'd rather deal in fact than with propaganda, or what some friends of someone told them. I wouldn't normally take a radiation monitor to the beach with me, so the suggestion that contacts of yours did so indicates they were looking for something anyway and may have had a point to prove?

My contacts are in scientific and tech. journalist circles - I have never had contact with CORE nor any other Cumbrian group.

Originally Posted by paul_b

I'm interested that even though the Irish Sea has a low tidal turnover, there still isn't any untoward radioactivity on the Wirral coast... Can't be all that bad then?

My team is only concerned with the Wirral and the Dee and Mersey estuaries and I haven't made any measurements elsewhere. When I went up to Aberdeen with a friend I deliberately took a Geiger with me but didn't have the time to do any useful measurements. I understand that the Sellafield area is the bailiwick of another team.

Originally Posted by paul_b

I really didn't want to get into the nuclear debate, so I'll probably shut up now, though if you really want to know more about radiation (I had thought this was a swimming forum), do let me know.

Thanks, I'd be pleased to hear from you, but it would have to be via email. If you are interested I can PM you. You will understand that I can't talk much about what I've been doing on a public forum as officialdom do seem to get rather excited where clicking Geigers are concerned. Can't promise anything but I might be able to have my VHS tape copied (or transferred to DVD) should you want to watch that programme again. It's not been played for some 20 years so I hope it's still OK. I should also declare that I have no anti-nuclear agenda but I do bristle when civil rights are infringed. Given that we abandoned fusion research in the 1950s so the military psychos could have their dangerous little fireworks to play with, nuclear energy is the only realistic option for at least 20-50 years.


Wildswimmer Pete

[GettingFaster]

Thank you, gents. I have thoroughly enjoyed this thread, even if I understood about one idea in ten! Nice to see a lively discussion that didn't descend completely into personal slagging off (though it did look for a minute that it might, which made watching it all the more exciting!)

[Wildswimmer]

Seriously GF, it is a concern to many people who live around the Irish Sea. Sewage pollution is eventually removed by natural processes, but radioactivity isn't. Like dangerous chemicals, radioactivity can also become more concentrated as it travels up the food chain. Most of us eat fish!

Wildswimmer Pete

[GettingFaster]

Originally Posted by Wildswimmer

Seriously GF, it is a concern to many people who live around the Irish Sea. Sewage pollution is eventually removed by natural processes, but radioactivity isn't. Like dangerous chemicals, radioactivity can also become more concentrated as it travels up the food chain. Most of us eat fish!

Wildswimmer Pete

Yes, Pete, I appreciate that. I also appreciated the way you two have been able to show that you know what you're talking about without getting silly, which is what my comment was about.

(And I seriously didn't understand much of what you were saying, but felt very reassured that you were saying it, particularly "no unusual radioactivity in Merseyside", which will be a relief to many and which was one of the few bits I did understand...)

[swimslikeabrick]

I know this is getting totally off topic for swimming, but doesn't this latest incident have to do with radium paint on aircraft dials? Apparently they do not let the public near the cockpits of old aircraft these days, so what of the guys that used to fly in them?

I suspect there is a lot of radium in landfills, I do not suppose anyone remembers the ABC minors who used to hand out luminous badges, well I reckon they are mostly in landfills by now, never mind all those watches and alarm clocks!

[paul_b]

Originally Posted by swimslikeabrick

I know this is getting totally off topic for swimming, but doesn't this latest incident have to do with radium paint on aircraft dials? Apparently they do not let the public near the cockpits of old aircraft these days, so what of the guys that used to fly in them?

I suspect there is a lot of radium in landfills, I do not suppose anyone remembers the ABC minors who used to hand out luminous badges, well I reckon they are mostly in landfills by now, never mind all those watches and alarm clocks!

Yes, the Dalgety Bay problem is one of radium dials disposal, or it not being done very well. As most of the planes they were fitted to were military, the relative risk of longer term radiation effects was probably insignificant compared to the other more pressing risks of wartime aviation, but yes, the Environment Agencies have recently run a campaign to safely dispose of radium dials from aircraft in museums, for example. A lot of radium painted goods have probably gone to landfill, though it is a material that is now under much tighter control. Pete's right that sewage does get broken down eventually, but even radioactive materials do too - it's the nature of them being radioactive that they decay, albeit over quite a long timescale. As I mentioned in an eariler post, nuclear operations are strictly regulated, but there are some materials that we were still merrily dumping in landfill quite recently - batteries, heavy metals and so on, that really never ever go away...

[Wildswimmer]

Originally Posted by swimslikeabrick

I know this is getting totally off topic for swimming, but doesn't this latest incident have to do with radium paint on aircraft dials? Apparently they do not let the public near the cockpits of old aircraft these days, so what of the guys that used to fly in them?

Apparently those most at risk were the ladies who painted the instrument dials with radium paint. Particularly as they regularly licked the tips of their paint brushes to maintain a sharp point. There were some flyers who did contract cancers attributed to radium dials but bear in mind the forest of instruments in the cockpits. Incidentally, should you have worn (or still do wear) a watch with a radium dial don't for heavens sake throw away a valuable watch. It poses no more risk than that from normal background radiation as long as the radium paint isn't disturbed.

Originally Posted by swimslikeabrick

I suspect there is a lot of radium in landfills, I do not suppose anyone remembers the ABC minors who used to hand out luminous badges, well I reckon they are mostly in landfills by now, never mind all those watches and alarm clocks!

Bear in mind that not all luminous items contain radium. Since just after WWII luminous paints have been long-acting phosphors that when exposed to strong light, will emit light for several hours afterwards. Used to be calcium sulphide doped with traces of bismuth but I understand that more efficient formulations are used now,

Remember the Trimphone? The luminous dial contained a "Betalight" - a tube containing tritium, a radioactive isotope of hydrogen, and a phosphor that glowed through bombardment with beta particles. Those have mostly been disposed of as hazardous waste, so if you see a luminous Trimphone for sale - grab it. There's no hazard posed by the by now almost exhausted Betalight.

I weep when I remember all the old radium-painted watches I played with as a child and never kept one. I've been trying to obtain an old "radium" watch for ages but whenever they turn up they go for seriously silly money.

Wildswimmer Pete

[swimslikeabrick]

Originally Posted by Wildswimmer

Remember the Trimphone? The luminous dial contained a "Betalight" - a tube containing tritium, a radioactive isotope of hydrogen, and a phosphor that glowed through bombardment with beta particles. Those have mostly been disposed of as hazardous waste, so if you see a luminous Trimphone for sale - grab it. There's no hazard posed by the by now almost exhausted Betalight.

Wildswimmer Pete

I do indeed remember the trimphone, my uncle used to have one, he also used to keep an old aircraft altimeter in his old Hillman Minx, which no doubt had one of those radium dials. He worked for the GPO and was an old style geek that is to say a Radio Ham and Hifi buff. Amongst the things he enjoyed telling his nephews about was exactly what those big 800 ft towers at Rugby were for and some hair raising stories about not touching the chain link fence when they were transmitting.

I used to be able to see them from Kitchen window, but like Criggion they are gone now.

[Dave_G]

Do you live in Rugby, swimslikeabrick? That is where I live, and I too used to be able to see them from my home.