THE TRUTH ABOUT GEIGER COUNTERS.. THEY DONT MEASURE PLUTONIUM & URANIUM RADIATION!!!!!!!

PLEASE PIN THIS.. IT IS VERY IMPORTANT INFORMATION

FROM LLRC [link to www.llrc.org]

Alpha emitters, Geiger Counters
- a clarification on monitoring for radioactive pollution

The principal alpha-emitting nuclides of interest are Plutonium and Uranium. To all intents and purposes only specialised and expensive scintillation counters like the DP2 Elektra can detect them in the environment.

Even then the detector window must be within 2cm of the radioactive particle. You won't do this many times because the window on the DP2 is so thin that a blade of grass will make a hole in it, and then it has to be repaired. Cheaper (but still costly) instruments such as the Gamma Scout which claim to detect alphas might possibly have some marginal response if a particle was on the detector window, but you will still have no way to tell what it was responding to.

Gamma signals will swamp any alphas anyway. The Electromagnetic Energy of alpha decay can be detected if a detector has the right proximity to the radioactive source material. This is true for beta, gamma and neutron radiation. They have to reach the detector. In air, some EM radiation travels inches, some travels feet and some travels miles (alpha, beta, gamma, neutron respectively). Some will pass through concrete and lead; some cannot pass through skin.

Alpha radiation attenuates in air within a couple of inches. These small all purpose GM counters you are asking about are used to measure Becquerels and use a formula to calculate Greys and Sieverts.

Any detected alpha radiation in an air-born sweep or a swipe of a human body is the result of coming within a couple of centimetres of the source material. In the case of alpha EM radiation, the radioactive source material will be floating or passing, stuck to clothing, skin or hair in the form of particulate (sub-micron sized radioactive dust particles). Uranium and plutonium particulate has an affinity for clothing due to filter effects of the surface material, static charging and humidity of the body. The most radioactive secondary sources in Iraq were the clothing of troops in the battle field.

If the air-born particulate or fall-out is an alpha emitter it will be detected by the hand held detector provided it is close enough (an inch or so) and the rate of decay is frequent enough to emit an alpha decay within the immediate area of the detector's reading face (window) or the detector pauses long enough at that point if the source is stationary. Frequently the operator will scan too fast to catch the decays when the frequency is low or the distance is greater than a centimetre. Proximity/distance, frequency and density make the hand held detection a 3 dimensional task. The type of detector and the type of emission must be compatible as well.

No GM (Geiger Muller) counter can identify the type of radiation it is detecting. An alpha probe designed to ignore all other types of radiation is needed for alpha-only detection. That is what I used in Iraq and Afghanistan, where alpha decay is accompanied by gamma emissions.

No GM counter can identify the nuclide source. A nuclide identifier is required (about $15,000 for a basic field portable identifier). I used an Exploranium in Iraq. We used gamma and beta detectors to find the hot spots and original sources and then narrowed in with alpha probes.

The GM counters can only read EM pulses, not the "type" of radiation (i.e. it cannot specify that it is alpha). They are set to give an accumulated reading of decays and or translate (unreliably) into biological effectiveness.

The emissions of radioactivity from the Japanese supercritical reactor cores and the spent fuel cooling ponds that are causing a threat to the liquidators on site are two kinds: gamma and neutron radiation. Both are extremely "penetrating" and extremely damaging as they pass through the human body like a microscopic bullet, slicing and cutting cellular material, and super-heating sub-cellular molecular targets (just as if they are a miniature grenade exploding inside a cell).

The second type of radiation is the emissions from any air-born particles carried out the plant, lofting into the atmosphere and travelling across Japan -- these have now reached Canada and the US. These particles are entrained by the mechanical disturbances of the fire-fighters' water being poured on the reactors, the hydrogen explosions, etc. These air-born reactor fission products (man made products inside the nuclear reactor) such as radioactive Iodine and Cesium are mostly beta radiation emitters. They do not exist in nature and they are accompanied by a host of alpha radiation emitters from the original fuel: Depleted Uranium and Enriched Uranium and artificial nuclide, Plutonium. Beta, gamma and alpha radiation will be emitted by the contents of these air-born materials spread in the vapors, steams and smoke plumes leaving the plants and travelling around the globe.

A single particle of these air-born radiation emitters entering the lungs can enter the blood stream, incorporate in human tissue and start a biological chain reaction that can cause cancer and other systemic illnesses. To claim they are not a threat to human health is a fallacious statement. It is statement of statistics regarding the likelihood of exposure and consequent illness, and nothing to do with the biological effects of contamination. These radiations emitting materials (dusts and particles) are extremely dangerous when internalized. They should not be breathed into the body, ingested in food or water or allowed to be absorbed through the skin.

There is a cause for concern. As we have already said, it is more than likely (in fact quite certain) that Plutonium and Uranium are part of the fallout mix. If the gamma signal goes above background you have to assume there are particles floating about that you definitely do not want inside your body. The problem with alpha-emitting particles is that although the range of their radioactive decays is very short, they are immensely destructive, killing cells and potentially mutating the DNA of cells which survive. The standard ICRP model of radiation risk takes an average of the energy of those decays as if it were distributed across large volumes of tissue and concludes that the risk is low. This is as stupid as believing that because it's safe to warm yourself by the fire it's equally safe to absorb the same amount of heat by eating a red-hot ball bearing.

At the date of writing we still know of no information from Japan on alpha emitters from the disaster. This is a serious dereliction of duty to the public.

Main page: [link to www.llrc.org]
Above article: [link to www.llrc.org]
[link to www.llrc.org]

UPDATES FROM LLRC

20th March
The UK's Foreign and Commonwealth Office is trying to confuse our supporters by lying about what Geiger Counters can measure - claiming that contrary to what LLRC says some can measure alphas. It's nonsense. Take note of it only to note that the authorities want to "keep the public confused", as President Eisenhower demanded of his own officials in the 1950s (REF: [link to www.llrc.org]

Original advice (16th March 2011)
People are asking for advice on Geiger Counters. In this emergency anything is better than nothing. There are lots of Russian Geiger Counters on ebay. Before you ask, we don't have a list of recommended models. With hindsight we ought to have researched this but we didn't get round to it and now we haven't enough time.

You need one that will measure down to background levels. This means it needs to be able to display 0.05microSieverts or MicroGrays per hour. Background should be about .05 to 0.1 microSieverts per hour (0.005 milliRoentgens per hour up to 0.01 milliRoentgens per hour).

"Civil Defence" models distributed during the Cold War are unlikely to be any use. We have seen adverts for the CDV-715, for example, which has a range with the bottom end starting at 0.01 Roentgens per hour. Natural background radiation should be in the range 0.01 milliRoentgens per hour down to 0.005 milliRoentgens per hour (1 milliRoentgen being one thousandth of a Roentgen). In other words the CDV-715 is 1000 times too insensitive to pick up even the highest likely value of natural background.

Do not worry about calibration (see footnote).
Don't wait until you think the fallout might have arrived. Take readings outdoors immediately to establish the baseline value of what's normal for your area. Note down the readings. Ideally, email us and tell us where you are and what your baseline reading is.

Keep taking readings regularly - several times a day. Don't panic if there's a small increase when it rains - that's normal. Take avoiding action (see below) if the reading increases to double the baseline value and at that point please tell us.

NOTE: We have said Geiger Counters cannot measure or detect the presence of alpha emitters like Plutonium and Uranium or beta emitters like Tritium and Strontium 90. This remains true but it is very likely that those contaminants will arrive together with gamma emitters like Caesium 137. To put it another way, if the gamma signal increases, make the precautionary assumption that it's a flag for the whole cocktail of radionuclides from the reactor and from the spent fuel rods that have been blown into the air or burned. Take what action you can:-

stay indoors and keep doors and windows shut,
drink bottled water (even if it's only tap water that you drew off and stored before the fallout arrived),
use tinned milk, don't eat local produce unless it was harvested earlier.

Footnote on calibration:
Purists and pro-nuclear critics will bitch about calibration (i.e. standardizing your instrument against a known radiation source). You must not worry about it. This is about public protection, so accurate values are nowhere near as important as any variations you find measured on your monitor. So long as you keep using the same Geiger Counter you have a reliable way of spotting the changes.

[link to www.umrc.net]
[link to www.llrc.org]