Nuclear Radiation Detectors
for Citizens

( to help detect 'dirty' radiation devices
that might be inflitrated onto
public transport and
onto various sites
within the United States )

(2007 Jan blog post)

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When I was growing up in the 1950s in the U.S.A., the nuclear-radiation concern on the minds of citizens was that Russia would strike the U.S. with nuclear bombs from aircraft, like high-altitude bombers.

In the 1960s to 1970s, the concern shifted slightly, to nuclear bombs delivered by rocket-propelled missles.

Nowadays, the concern is hand-carried "micro" radiation bombs, deliverable in briefcases and the like.

    [This is no laughing matter. I remember a newspaper report, back around the 1970's, of a case, in Germany, where a worker with radioactive material had brought together two small amounts of radioactive material and the result was a small explosion that injured and contaminated the worker. Nuclear bombs do not have to fit the stereotype of city-leveling. They can be city-block leveling --- and contaminating.

    And then there's Iran ... and Pakistan ... and North Korea ... and ... They are not laughing matters.]

It would be nice if we, the citizens of the U.S., could count on a government agency to detect any suspicious amounts of radiation coming into the country.

But, because there are so many possible delivery vehicles (ships, planes, trucks-and-cars) and entry points (seaports, airports, border crossings), there seems to be no way for a central government agency to detect any-and-every incursion.

In fact, even 6 years after the 9-11 (2001) New York City Trade Towers debacle, there are reports that only about 2 percent of the containers delivered by ships to U.S. ports are scanned for radioactivity. So ...

I would feel a lot better (that is, sleep more peacefully at night) if my fellow citizens and I were carrying radiation detectors --- some on our persons or some in our cars --- on the subway to work, at work, to shopping malls and amusement parks and stadiums, on vacations, etc.

In other words, scenarios where I would envision people serving as 'distributed radiation alerters', via a small radiation detector carried on their person, are in a subway station or subway car, in an air terminal or airplane, in a bus terminal or bus, in a railroad terminal or railroad car, on a waterfront, on a boat or ferry, in a public building like a library or a mall or a stadium, or on a crowded city street.

You can start finding more information on the issue of radiation contamination at this web page.

If I find any interesting links (such as info on small nuclear explosions like the one in Germany that I mentioned above), I will post them here.

Some Detectors :

I have done some searching on the internet for affordable radiation detectors --- detectors sufficient to give warning of danger, so that authorities can be notified, to investigate with more sophisticated detectors.

It turns out that most advertised radiation detectors available in the U.S. cost from about $100 to about $800. On the other hand, there are some simple-but-reportedly-effective detectors available from Russia (motivated by the Chernobyl disaster, no doubt) that are available for about $20 to $80.

I include links, below, to some sites with information about these various radiation detectors.

Some of the links provide information on radiation types (alpha, beta, gamma, X), units of measure (Roentgens, rem, Sieverts, Grays, Curies), and radiation levels --- from "background" radiation to radiation levels from various common and uncommon sources.

It helps to keep in mind that the radiation counts from a source are inversely proportional to the square of the radius (i.e. distance) from the source. So the radiation counts from 2 feet away from a source will be four times lower than from 1 foot away. And counts from 10 feet away will be only 1/100th (one percent) of the counts from 1 foot away.

Hence, if you have a keychain radiation detector that only detects quite intense radiation sources (say, when you hold the detector only a foot away from the source), then it may be difficult to find a mild test-source that will register on the detector.

I plan to include a table of radiation sources that can be used for testing --- along with quantitative radiation levels that can be expected from those sources. Back in the 1960s, I had a wrist watch with numerals on the dial made from radium. If I had that watch, it might make a good test source.

A keychain radiation detector called "Micro Bomb Detector" (MBD) is available from many web sites for about $100 to $200. It is not very sensitive. If it goes off, you should probably get out of the area as soon as possible, to avoid accumulation of a significant radiation dose to your body.

Here is a video (mpg file) that illustrates the directional capability of the MBD, as well as how the MBD signals three different levels of radioactivity --- by long-long, long-short, and short-short beeps.

Unfortunately, this detector is always on --- even if you have the detector in your home --- on your dresser or in your pants pocket in your closet. The battery is not easily removed. And it is a small disk shaped battery, not a very common battery.

I would prefer a detector that has an on-off switch --- or at least an easily-removed battery. And I would prefer a commonly available battery, like a AAA battery that is available in most drug and hardware stores.

A Note Before Proceeding :

I think the prices of most of these key-chain devices is too high for the components involved in making them. Furthermore, I am concerned that most of these web sites do not offer low-level nuclear materials (say, encased in glass) by which one could make sure the device is doing its job.

I have to wonder how many of these are scams. That is why I wish the federal government would get behind certifying workable devices and making them available in such numbers that the price is more reasonable.

I remember back in the 1950's when Popular Electronics magazine carried articles on how to build a Geiger Counter (or simple radiation detector).

It might be much cheaper for someone to build their own radiation dectector from parts, after finding such electronic schematics.

By the way, I think it is better to tolerate some false alarms by overly skitish citizens than to leave radiation monitoring in the hit-or-miss (mostly miss) position that we are in now.

This same detector seems to be available under at least one different name, such as RadDetect (about $170).

Here is a video (wmv file) that illustrates the directional capability of the RadDetect device, and here is a video (wmv file) that illustrates how RadDetect signals three different levels of radioactivity --- by long-long long-short, and short-short beeps.

The shape of the case, the alarm sounds, and the light signals appear to be identical in several of these pocket detectors.

It would seem that there is a single manufacturer providing multiple marketers of these devices. Is this extra level in the supply chain the cause of the rather high price?

Also see NukAlert (UK) and NukAlert (US). (about $190)

More info on the NukAlert keychain detector.

Info on "Polimaster" radiation detectors. (about $300 to $1500)

These are too pricey for my intended purposes --- early detection of a possibly dangerous source of radiation. I am willing to leave it to others to determine exactly what kind of radiation is being emitted (alpha, beta, gamma, X, neutron).

At least one site ( has cast suspicion on devices like the ones above (solid-state without a Geiger-Muller tube) saying that it is doubtful that they can actually be used as directional detectors. This site seems to have some quite detailed review and comparison information on detectors.

Here are a couple of sites that give a rather glowing evaluation of a couple of Russian radiation detectors that are available for about $20 to $30. (The first link is at the "doubter" site,

These Russian detectors were available via E-bay (in 2007) from a Russian collectables dealer named Annakozub.

I need some mildly radioactive material to determine if one of these (the DRSB88) does indeed work --- and how long the battery will last if I turn the unit off when not using it. It has the nice feature of an on-off switch --- and a fairly easy-to-replace battery --- a commonly available AA battery.

Here are some documents that came on a CD with the "Micro Bomb Detector" (MBD).

Here are some web sites with information on radiation and detectors.


I think U.S. citizens should BE PREPARED to help detect terrorist dirty radiation bombs.

The Federal government is probably not going to help citizens get detectors --- even though links above indicate they are spending 100s of millions of dollars on detectors. That amount of money would buy more than 6 million of the Russian $30 detectors --- and more than 2 million $100 detectors.

I would feel a lot safer having detectors in the hands of more than millions of citizens, than having detectors in the hands of a few government agencies.

It will probably be up to forward-thinking states, like California, to come up with a better plan than Homeland Security is pursuing.

But, most probably, it is up to us, the individual citizens, to act --- and soon, judging by activities in Iran and North Korea and elsewhere.

For more info:

To find more information on nuclear radiation detectors, you could try some WEB SEARCHES on keywords such as :

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Page history:

Page was posted 2007 Jan 11.

Page was changed 2008 Dec 24.
(Small changes.)

Page was changed 2009 Aug 25.
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Page was changed 2013 May 03.
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Page was changed 2019 May 26.
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