Tritium detection?

[Bright Scouter]

I'm sure everyone has heard by now, about the incident where a radiation detector at the fire station went off recently. The firefighters watched two guys walk by the station carrying a gas can. It went off and they though it was a fluke. It went off a second time as they walked back. By then they were suspicious. The third time it went off was as the two guys went by in the car that now had gas in it. Police stopped them down the road. After an hour or so talk, they decided it was the fact that one of the two had just had a radiation treatment.

Now, assuming the news stories are right and this is not an urban myth,,, Any chance they are sensistive enough to pick up someone walking around with a few glow tubes in his/her pocket? I really doubt it, but thought I would ask and see what everyone thinks.

 

[AnotherDaveH]

Tritium is a beta emitter and the radiation produced will not escape from the capsule. Alarms will be set off by things that produce gamma radiation.

 

[Roy]

Even if the capsule did leak, a standard radiation survey meter will not detect Tritium! It takes very special equipment to detect Tritium. As long as you don't injest the tridium (through the mouth or a puncture wound), it will not hurt you.

 

[gessner17]

I broke a tritium tub (LH type), is this real bad?

 

[greenLED]

[ QUOTE ]
Bright Scouter said:
After an hour or so talk, they decided it was the fact that one of the two had just had a radiation treatment.

[/ QUOTE ]
/ubbthreads/images/graemlins/confused.gif I am not sure how this can be possible. Can someone enlighten me?

 

[mattheww50]

Radition treatment is not necessary external, and it is not necessary treatment either. Radioactive isotopes are routinely used in scans, Tc99m is a favorite. Seed/needle implants for cancer treatment often involves Cs137 or Au198 (long ago Radium was used). Treatment for overactive thyroid, or thyroid cancer is a hefty, or heftier does of I131, and there are records of such patients setting off radiation alarms on crossing into New York City.

PET testing also involves administering radio labeled compounds.

Tritium on the other hand is very difficult to detect. It is a beta emitter, and a very low energy one at that.
Each Tritium decay produces an electron at about 6Kev.

The CRT you are probably reading this message on has phosphors that are being illuminated by 25Kev electrons.
since you don't get measurable radiation exposure working at your computer, or watching TV, you get the idea that even 25Kev electrons don't go through much.

Even in room air, a 6Kev electron won't get very far (inches). So the ability to detect tritium even in a vial is just about zero. I just tried to my geiger count which goes down to .01mr/hr, and even holding the glow ring right up against the tube with the beta sheild up, NADA, nothing, zero (and the counter works, there is a very small test source on the side of the counter).

 

[AnotherDaveH]

I live near where this particular story happened and heard about it on the local news. They never did say exactly what treatment this patient had, but a radiation oncologist that was interviewed said this was most likely Iodine 131 being used to treat thyroid cancer.
Tritium is pretty tough to detect. I've done some work in radiochemistry and was involved in a tritium contamination accident in the mid 80's. One of our hoods had a vent that failed to seal and a pretty good load of tritiated water leaked into the lab. My boss and I didn't know about the leak until we did our routine tests of urine and lab swab samples in the scintillation counter (again, "normal" detectors don't register). We both received a pretty good dose and he lost his NRC license to handle radioisotopes for failing to report the contamination. My dose wasn't high enough to be of a concern, but it was very chilling to see 0.1 ml of my urine move the counter needle to about half scale.

 

[gessner17]

So breaking one of these is nothing to worry about?

 

[AlphaTea]

Here is what I can tell you from PERSONAL experience.
I calibrate and repair radiation detection instruments for a living. A New Glowring will show about 150 cpm > bkgd on contact with a standard handheld GM type frisker probe. It may or may not (50/50)alarm a Personel Contamination Monitor with P-10 gas flow proportional detectors with an alarm setpoint of 5000 dpm. It will not set off a Plastic Scintillator type Portal Monitor set at 25 nCi (25 nano-Curies). The energy from tritium decay is just WAY too weak. It aint squat folks. Tritium is Hydrogen with a couple of extra neutrons. Being hydrogen, if the vial breaks tritium will do what hydrogen does, it will go straight up because it is less dense than air. Tritiated water is another subject though. it is water that uses Hydrogen-3(tritium) instead of regular hydrogen. When you spill water it evaporates into water vapor not hydrogen and oxygen. It is more dense and readily mixes with air. Tritiated water is chemically exactly the same as any other water. It is very easily absorbed and difficult to get rid of.
HOWEVER, Back before Thanksgiving last year I had a Cardiac Stress Test and I was given 34 mCi Tc-99m and 4 mCi Thalium 201. I read 84mR/hr on contact with my chest. I could not get within 100 feet of any of the above listed equipment without setting off alarms. I had to be isolated from my co-workers for a week so as not to give them dose that was not occupationaly related. It was around valentines day before I did not register as being contaminated.
So, that being said, yes it is possible that one of the guys in the car had a recent medical treatment, and it is highly doubtful and very unlikely that you can or will set off any radiation detectors with your tiny little Glowring.

 

[greenLED]

This is very interesting, I had no idea radiation treatment could be that powerful.

 

[mattheww50]

The problem is the Thalium 201. The Tc99M has a 6 hour half life. It is also doesn't mimimic any ions used in the body (Strontium and Radium are in the same family as Calcium), so it tends to wash out easily as well.

Tc is strange stuff because all isotopes are radioactive, and none has ever been found to occur naturally on earth (half life is way too short).
It is all reactor produced.
The Thalium 201 is 3 day half life, and that's the problem. Thalium has a peculiar afinity for certain parts of the human body. It is hard to get rid of, and is in fact very toxic.

 

[127.0.0.1]

hey ho
thread from the dead. I back up what AlphaTea said...

FYI on trits and do they emit anything. YES they do emit some gamma rays in the form of low energy xrays

I have a new Geiger–Müller detector and find these facts about GTLS tubes I have

piling the loose trits I have around the detector tube does raise the CPM.
average background 12-24. with a lot of small trits (9) right under the tube, it goes up to 50-60CPM

If I pile on more trits, say 22mm tubes, it goes above 100, 130 if I add another tube.

so, yes detectable ionizing radiation can come from trits. less if the trits are in a plastic case,
but not zero...zero beta, but non-zero gamma.
----
this is not beta radiation, it is secondary xrays (low energy gamma radiation) created
by Bremsstrahlung effect. low-energy Beta hits the phosphors and glass and this creates
some lower energy secondary gamma rays, which do leave the glass vial and are detectable
on a beta-gamma detector. the effect not noticed at 1 centimeter distance.

what does this really mean ? the amount of detectable xrays are still considered completely safe
and of no real added risk any more than airplane rides...but it is not zero. so, knowing this, I would
not carry a trit enhanced item on the very same spot in my clothes day in and day out, I would move it
around. I would probably not wear one on a necklace. even if I did swim in a tub of loose trits, my
risk is maybe increased by a factor of 1 millionth.

anyhow, I still carry trits and have them all over the place and on my lights. everyone is at far more
risk of inhaling radon (alpha emitter) or dust from fertilizer (or normal house dust) and getting that in the lungs
where it can do actual damage, vs very very few low energy xrays that cannot penetrate the skin more than 1cm or less.


I am not crying wolf and not trying to steer you away from trits, but facts is facts and they do emit some secondary gamma.
hey I have the equipment, and other tests seen on the 'net back up what I am able to see.

I am not a physicist so I cannot elaborate specifically on every particle I detect and it's root cause,
I can only detect the ionizing radiation and difference in CPM when trits are right up against the detector tube.
trits on the detector case ( a few mm from the tube) do not raise the CPM

 

[uk_caver]

I hadn't realised how old the thread was until I read "...The CRT you are probably reading this message on...".

 

[TEEJ]

I hadn't realised how old the thread was until I read "...The CRT you are probably reading this message on...".

LOL

Mine has a little guy inside with a chisel and a hammer, and I have to wait for him to chip the thread onto my screen to read it.

 

[DIΩDΣ]

LOL I have to admit my pc at home still sports a 17" KDS Avitron monitor I bought new back in 99-00-ish timeframe. Actually its the only computer monitor I have ever bought its been used through probably 3-4 pc's I have built. Sure the laptops came with LCD, but I loved that Avitron (think it was an off brand of the Sony Trinitron) and since its still working I'm still using it.

 

[uk_caver]

I really liked my old (trinitron tube) 19" Iiyama Pro, which I used pretty heavily for ~15 years or so, though towards the end of its life, it occasionally needed some persuasion to turn on (something ageing in the PSU, I guess), and it finally died (along with the Belkin UPS it was plugged into) when a power fluctuation hit, though everything else in the house survived.

 

[Norm]

This thread is about Tritium detection? not computer monitors, not sure if anyone noticed.

Norm