Good radiation detectors
With nuclear blustering starting up again, one can take a trip back to the 80’s when world-wide nuclear Armageddon was literally just 90 minutes away at any time – and some important information about radiation detectors and Geiger counters.
Back in the day, these old yellow box-like Civil Defense Geiger Counters were scattered around just about every community:
There were numerous different models that operated differently depending what they measured. These models are now over 50 years old. Radiation detectors require calibration and regular testing to give anything remotely like a good reading. You can often find these at military surplus stores for well under $100, but unless you test them against known sources and levels it’s difficult to trust detectors this old. Especially because they were often abused/poorly stored.
Today, you can find a lot of radiation detectors on the web. However, one needs to understand what they are buying before they jump in. Two of the biggest factors for a detector are: radiation range and radiation type.
Why range matters: 3.6 Roentgen – Not great, not terrible
The vast majority of Geiger counters you find online are for low radiation dosages. How low? They often max out at values like 32 millirem (1/1000th of a rem) per hour. While this is great for the amounts of radiation the average person might encounter via radon, food, or minerals, how would it fare during a nuclear war or serious nuclear accident?
According to the scientists at the Oak Ridge National Laboratory in their 1987 “Nuclear War Survival Skills” document, “Instruments that measure only milliroentgen-range dose rates are sold for war use by some companies. Since most Americans have no idea what size of radiation doses would incapacitate or kill them, and do not even know that a milliroentgen is 1/1000 of a roentgen, some people buy instruments that are capable of measuring maximum dose rates of only one roentgen or less per hour.” (One roentgen is equivalent to one rem.)
The book instead says that a meter that “can measure one roentgen per hour (rem) is far too low to be of much use in a nuclear war.” So, just like the instruments at Chernobyl that could only register 3.6 roentgen/hr, devices that only measure millirem/hour are essentially useless during a large nuclear accident or attack. They would almost immediately be maxed out and tell you very little.
What you need is a high-range radiation detector – something that can read up to hundreds of rem/hour – if you want it for a survival tool after a serious nuclear accident or war.
Detected Radiation Types
The next important factor is what TYPE of radiation a detector can measure. There are 4 major types that would be important in a nuclear accident or attack. Alpha, Beta, Gamma, and X-ray radiation. Alpha radiation is the lowest penetrating type of radiation, clothing or even a sheet of paper is sufficient to protect you from alpha radiation. Its biggest danger is ingesting alpha particles by inhaling or eating contaminated dust/food. They are dangerous if they get inside your body – this is why wearing a good mask is important.
Beta particles are slightly more penetrative than alpha, but still blocked easily by wood or thin metal layers.
Gamma radiation is much more dangerous. It can penetrate all but thick concrete, lead, or other heavy shielding. Its penetrative power is the most dangerous.
X-ray radiation is pretty self explanatory as we are familiar with them from dentist offices to all sorts of medical diagnostics. X-rays are usually short lived and emitted in tremendous amounts during nuclear blasts.
For military purposes, most of their detectors only record X-ray and gamma levels. These are by far the most dangerous types of radiation. Your detector should at least detect those 2 kinds of radiation at a minimum.
The biggest thing to know is that after a nuclear attack or serious accident, there will be rising and falling amounts of different nucleotides over time as higher energy sources decay to lower ones:
The most important factor is that time is your friend. The first 2-5 days are the most critical time to stay sheltered and to protect yourself from contamination and fallout:
This would be done primarily by staying in a safely shielded/enclosed shelter, taking thyroid pills, wearing masks to avoid inhaling particles, and by only eating clean food and water. Most guides would recommend at least a month’s worth of supplies before any help would arrive.
Calculating your dose
When reading a radiation detector, reading the radiation level alone is not enough information to figure out if you are in danger. Dosage of radiation is a calculation of radiation level AND time of exposure. Most detectors read values in microsieverts (uSv), millisieverts (mSv), or rontgen per hour (rem). To calculate your dosage, you need to calculate the radiation rate along with the time you were exposed to it. If you are in a 10mSv (or 1 rem) environment for 1 hour, you would receive a 10mSv (1 rem) dosage. If you were in that environment for 2 hours, you would get a 20mSv or 2 rem dosage. If you were only in that environment for 30 minutes, you would get half that dose – 5mSv or 0.5 rem.
Here’s some dose rates of some places/objects to give you an example, or watch this excellent video by Veritasium
|0.17-0.30||0.000017||Average background radiation|
|2.5||0.00025||Flying at 30,000 feet – https://www.youtube.com/watch?v=XuQgVGDENbU|
|5.25||0.000525||Chernobyl near the facility viewing area – https://youtu.be/9DWnjcSo9J0|
|5.7||0.00057||Maximum dose rate to reach the 5000 mrem/year max for US radiation worker|
|6.85||0.00068||Rate to reach maximum reasonably safe dose (60mSv) in one year|
|100-125||0.0100||1.5km from the Fukushima plant in Japan in 2011|
|600||0.0600||Chernobyl firefighter’s clothes in basement of Pripyat hospital in 2017 https://www.youtube.com/watch?v=C4g3FkXUhx0|
|1500||0.15||Chernobyl firefighter’s clothes in basement of Pripyat hospital in 2014 |
|11,000,000||11,000||Workers clearing the Chernobyl roof as bio-robots (fatal dose in 115 seconds – most got 40-90sec worth)|
So what constitutes a dangerous amount of radiation?
The average person receives about 1.5 to 3.5 millisievert (mSv) per year via normal background radiation – or around a reading of 0.17-0.39 microsieverts (uSv) per hour (a microsievert is 1/1000 of a millisievert).
Example: Calculation of the average full-year dose is:
0.17uSv/hour * 24 hours/day * 365 days/year = 1489.2 uSv/year = 1.4892 mSv/year. (or 0.14892 rem/year)
Oak Ridge National Laboratory in their 1987 “Nuclear War Survival Skills” document say that in the event of a nuclear war – ‘small’ doses of around 6 rem per day should “produce no incapacitating symptoms. The human body usually can repair almost all radiation damage if the daily doses are not too large.” Outside of war time, regulations say a US radiation worker should have no more than 5 rem, or 50 mSv for a WHOLE YEAR exposure. That would be an environment with no more than 0.00068 rem/6.8 uSv per hour exposure. After a war, if you wanted to stay below a 6 rem/60 mSv per day exposure – you would not want to be in any environment over (a frighteningly high) 2.5mSv/hr (or 2500uSv/hr). You might survive those rates, but would almost certainly would experience serious issues because your whole year dose would be a terrifying 2190 rem/yr (21,900 mSv/yr) vs a normal exposure of <0.2 rem/yr (2 mSv/yr)
For whole doses, you are now looking at these kinds of effects when you calculate the dose over time:
|0.035||0.0035||Cumulative dose of a cross-country US flight|
|0.1||0.01||1 chest X-ray|
|2.0||0.2||1 year of average background radiation|
|50||5||Maximum yearly dose for US radiation worker|
|60||6||Limit of maximum reasonably safe annual dose|
|80||8||Astronaut who spends 6 months in space on space station|
|50-100||5-10||changes in blood chemistry. Possible later effects or chromosomal damage|
|120||12||Average reported Chernobyl liquidator dosage|
|160||16||Radiation smoker’s lungs receive in one year (from radioactive Pu and Pb in tobacco)|
|250||25||Average dose of a Chernobyl bio-robot during their 40-90 second work session on the roof of Chernobyl. https://youtu.be/XzfsfYnuc8c|
|500||50||Nausea, within hours. Reduction of white blood cell count.|
|750||75||Hair loss, within 2-3 weeks|
|1000-2000||100-200||Mild radiation sickness within a few hours: vomiting, diarrhea, fatigue; reduction in resistance to infection.|
|2000-3000||200-300||Serious radiation sickness effects as above plus hemorrhage. Exposure is lethal to 10-35% of the population after 30 days.|
|3000-4000||300-400||Serious radiation sickness; also marrow and intestine destruction; Death in 50-70% of cases.|
|4000-10,000||400-1000||Acute illness, early death and lifelong health effects. Death in 60-95% of cases.|
|10,000-50,000||1000-5000||Acute illness, early death in days; Death in 100% of cases.|
Modern radiation detection
So with that background, what kind of detector should you buy? What you need during a serious nuclear accident is a radiation detector that can minimally detect X-rays and gamma rays up to 300rem (3000mSv) with trustworthy results. This is what is used by military forces around the world and the range those old yellow civil defense devices could measure.
Unfortunately, when tested, a great number of high-range radiation detectors give dangerously inaccurate results. Many that are sold on the internet are not calibrated nor tested – when many were tested by Oak Ridge, they often reported within 20% of true values on lower doses, but were often off by more than 80% at higher ranges. They found some read 100 rem/hour when the true radiation level was closer to 500 rem/hour. Further, many devices will most likely not survive EMP that would occur during a nuclear attack.
So, maybe we should steer clear of things you buy on Amazon or eBay. Their dose rates are too low, or are likely dangerously inaccurate. What you need is a real professional tool, and that means some serious money.
The cheapest high-range models I could find with a reasonable reputation are also ones seen in Ukraine around Chernobyl: Ecotest MKS-05 Terra-P detectors. They measure from 0.1 uSv to 9,999mSv/hr (±25%), detects X-ray and gamma and a calculated beta exposure. With a ±25% range of error it is not great, but definitely useful as a high-range device. It also acts as a dosimeter. They cost around $400 and seem to be well reviewed. Just be sure to buy them from a reputable vendor.
The next high-range model with much better tolerances and seems to be used by scientists around Chernobyl are the Thermo Scientific RadEye survey meters.
Some of their detectors are able to register from uSv all the way to 10 Sv/hr (1000 rem). Noteably the RadEye PRD-ER4, SPRD-ER, and G-Ex and GF-Ex. These models cost an eye-watering $1900-$2300. The GF-10-Ex can reach 3 Sv/hr (300 rem) and can be found for around $1650
Besides those, you might also consider the lower dosage meters in the B series:
Youtube videos often use the B models in contaminated zones like Chernobyl – like the Thermo Scientific RadEye B20-ER. These kinds of devices are for first responders. They detect alpha, beta, gamma, and X-ray radiation. Unfortunately, even the -ER (extended range) model is limited to reading from 0.2uSv to 100 mSv/hr (10 rem/hr). They also calculate cumulative doses so you don’t need to keep a mental calculation as you move through different radiation levels. Unfortunately, they also cost about $2000 – so they are also very expensive.
Gamma-Scout is a German made device with good calibration, is well reviewed, and used by numerous people during radiation scouting events around Chernobyl/Fukushima. It registers alpha, beta and gamma emissions from 0.1 to 1,000 μSv/h. So, it’s not useful as the RadEye due to the limited range, but good for lower-dose environments. Costing around $450, you could buy this and the Ecotest for under $1000 and likely cover your bases.
- IOSat – https://www.anbex.com/
- Department of Homeland Security Radiation Detector market survey report.
- RadEye – complete guide to all models
- G series – https://www.thermofisher.com/order/catalog/product/425067670G series purchase link: https://www.fishersci.com/shop/products/radeye-g-series-personal-dose-rate-meters/p-4531305
- Gamma-Scout – https://www.gamma-scout.com/en/alert/
- EcoTest Terra-P – https://ecotestgroup.com/products/terra-p/