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3/11/2012 - Radioactive gauge, lost and found

This is taken from the IAEA News Channel (Nuclear & Radiological Events)

Radioactive gauge, lost and found


[12 October 2012, Greece, Aluminium SA, posted 02 November 2012, INES = 1 (Final)]

On October 12th 2012 during the removal of a detector from an industrial densitometer, technicians of a greek aluminium company in Voiotia realized that the lock mechanism of a Cs-137 source (5 mCi - 1993), as well as the source itself were missing. Two engineers, trained in radiation protection, blocked the area on a 10 m radius and started the search using a portable detector.

The source was found near an open surface drainage stream covered in a sediment crust at a distance of a few meters from the housing. Using a shovel and a lead container they collected the source and transported it to the source storage facility within the company premises. The lock mechanism has not been found. The maximum dose rate indication on the portable detector was 320 μSv/h, while the cumulative dose was no more than 15 μSv, which is in accordance to the calculations performed by GAEC.

After the source recovery, GAEC was notified about the incident. Soil samples collected from the place where the source was located and the wipe test performed on the source showed that there was no radioactive leak to the environment. The undergoing investigation in the industry indicates that the last time the source was known to be within the shielding was on June 26th 2012. On that day due to pipe maintenance operations, the source housing was removed for a short time from its proper position. The loss of the source was not noted earlier due to the fact that the densitometer was out of use.

Assuming that the source has remained at the position it was found for the whole period it was missing, given the fact that it was in a very low occupation area, and according to the information provided by the industry, workers performing occasionally operations in proximity to the area have spent there no more than a total time of two hours.
GAEC has verified the dose measurements and calculations performed by the company technicians.

The case is not closed yet since additional information from the company regarding the investigation of the causes of the incident, and the future actions to be taken, is expected.

Taking into consideration

• the source category (5)
• the fact that the source positioning was not verified for a period of about four months
• there was no exposure of any members of the public or workers
the provisional INES rating is "1".

The incident log for the above event can be read at the following link: IAEA News Channel.

Ionactive Comment

In the grand scheme of things this is not a serious incident. However, I have highlighted it to show the difference between a good comprehensive write-up, and an inadequate one. Just compare this with the two Belgium cases noted in the previous blog entry. Then compare the seriousness of each event. Something not quite right ...

30/10/2012 - Radiation Safety in Belgium

What is up with radiation safety in Belgium? Two significant incidents within a period of 4 weeks.

The two incidents are taken from the IAEA News Channel (Nuclear & Radiological Events)

Overexposure of a radiographer


[19 September 2012, Belgium, Stork Technical Service, posted 18 October 2012, INES = 2 (Prov)]

A radiographer went in a bunker where industrial radiography operations were made. The ionising source was a X-ray machine (225kV - 4mA).

The radiographer thought that the irradiation was finished but this was not the case and he was exposed.

According to the biological dosimetry, the radiographer received a whole body dose below 200mSv. At the moment, the licencee is making a reconstitution of the incident to better determine the dose

The incident log for the above event can be read at the following link: IAEA News Channel.

Overexposure of a worker


[05 October 2012, Belgium, IRM group sa - Alleur, posted 17 October 2012, INES = 2 (Final)]

A worker made adjustments on a X-ray machine (65kV - 1.8mA) despite the fact that the device was in test.

The worker received between 5 and 7 Gy on each hands during the intervention. The whole body dose that he received is 1.4 mSv.

The incident log for the above event can be read at the following link: IAEA News Channel.

Ionactive Comment

The two reports are rather sparse but the mind still boggles how each of these incidents could have occurred. Even the most basic radiation safety standards should have avoided such exposures.

Generally industrial radiography accidents tend to involve radioactive sources - it is not so easy (but still possible) to provide a ‘fail-to-safe' system for live sources as opposed to radiation generators using an electrical supply (i.e. x-ray units). If a radioactive source becomes exposed then it has to be dealt with by the well-known protection principles of time, distance and shielding (hopefully following contingency arrangements).

With an x-ray system, and certainly low energy generators (i.e. excluding activation radiation from a high energy linac), simply pulling the plug removes the radiation hazard. In addition, since the source of radiation is electrically driven, it is easy to incorporate safety features such as flashing beacons, audible warning (pre-warn and exposure underway), emergency off buttons and pull cables etc.

So whatever went wrong in Belgium appears to illustrate a significant lack of basic radiation safety practice. There is no way that either individual should have been able to approach a live x-ray system without knowing it was producing ionising radiation. Furthermore, both incidents illustrate that either radiation monitoring / active dosimetry was not present, or was not switched on (or working). Management, supervision and training are also lacking. I really do not think it can get much worse. Total fail.

13/10/2012 - Why Ionactive, the UK Radiation Protection Adviser (RPA)?

This short blog entry is almost not worthy of a blog, could have been done as a tweet. However, the other day a client asked me ‘Why are you called Ionactive Consulting - where did the name come from?'. This took me back a bit as I had always thought it was obvious, but perhaps not?!

Over 10 years ago I was sitting at home scribbling on a piece of paper words that could somehow combine to form a new company name. I had already one or two clients as a sideline to my full time Radiation Protection Adviser role at Imperial College London. It looked like this ‘hobby' could grow but I decided to first concentrate on a website. In order to develop the website I needed a name. So I began to write down words:


With rather little inspiration (if I am honest), I just looked at the word ‘Ionising' and the word ‘Radioactive' and split them, taking the ‘Ion' and the ‘Active' and joining together as IonActive. In fact for some time I kept the capital ‘A' in the middle but later dropped it to a simple ‘a'. The first website was developed totally be myself - I had absolutely no web skills and in those days the free website makers were not really around. So I got myself a copy of DreamWeaver and started to play around. Here is my first effort:

First Ionactive Website - many moons ago!

And my second effort:

The next Ionactive website - a little progression

By my third effort (which took about a year to put together) I had come up with something that was respectable, if still rather amateurish. The important thing about this website, and I really believe Ionactive was unique at the time, is that it was 80% information and 20% commercial. This was just at the time that Google was really beginning to look at content over simple links to and from sites. I think this is how Ionactive really got its foot in the door.

Third Ionactive Website effort!

Of course now all my major competitors (both large and small) have caught up to some extent. Information is the name of the game for good websites. It is therefore a sad fact that I have less time to work on the current Ionactive site - too much work and too little play. This of course is a good thing in some ways since the RPA work is my full time job / career. However, I must not forget that Ionactive grew from an information provider and therefore time must be put aside to keep the resources side of the website up to date and fresh. Therefore in the coming weeks I will be actively refreshing all the pages. So Google, look out!

4/10/2012 - Radiation Protection Adviser (RPA)

Been an interesting few weeks in the radiation safety world of Ionactive! I have been a Radiation Protection Adviser (RPA) for a number of years now, but I'm still on that path of continual learning and always have to keep my eyes and ears open!

RPS Training

Ionactive RPS Training Resource

September started off with the monthly Radiation Protection Supervisor (RPS) training course. We continue to run these more or less monthly at our training venue in Great Missenden, Buckinghamshire. What I like about our courses is the variety of delegates that attend. Whilst the courses are compact (all done over two days), we deal with all ionising radiation uses (i.e. sealed and unsealed radioactive sources, x-ray generators etc). This means delegates come from almost every area of radiation use (industry, research, security, medicine, emergency services etc). It makes the courses interesting for both trainer and delegate, and this also helps me with my own continuing professional development (CPD).

I have been analysing the most recent delegate feedback. Here are a couple of examples:

"This course has met all expectations; however would it be possible to supply some pre-course information as some delegates start the learning process with very little knowledge. The course presentation was excellent and fully met objectives" (MT, RPS Delegate September 12).

This is welcome feedback and the advice is noted!

"The course presentation was very professional with a very detailed file. Good success at meeting learning objectives - feel reassured that I am able to perform my role"(AB, RPS Delegate September 2012)

Contingency Training / Exercises

Ionactive Exercise Resource - industrial radiography radioactive source

Later on in September I took off my Radiation Protection Adviser hat and slotted into the role of Exercise Manager for a Nuclear Licensed site. This is always good fun but also quite stressful (no doubt for the players, umpires and manager!). In this role Ionactive writes the scenarios, liaises with partners (e.g. casualty actors and emergency services), and runs the exercise on the day. The pre-exercise was based on an Ir-192 radioactive source becoming detached from a control line during industrial radiography (with an injured person near by). The main exercise involved a casualty falling down a storage pit, being injured and located near some significant radioactive sources. I was very impressed how the players (staff) and emergency services dealt with both scenarios.

Radiation Safety Training - Emergency Services

Ionactive CBRN / HAZMAT training for emergency services

Later on in the same week we ran a one-day radiation safety awareness / update session for the Fire and Rescue service. This is always an enjoyable session and we got to use some radiation / contamination simulators to provide practical monitoring experience. Live (radioactive) sources were also included in the training to demonstrate real monitor response. Plenty of exercise scenarios were included. One delegate later provided some feedback reporting ‘...nothing but praise for your ability to present the subject in an engaging manner with excellent presentation skills...'. A job is a job, but getting feedback like that is always the icing on the cake.

The Great North Run

X-ray dose rate monitoring at curtain entrance - Ionactive

Ionactive provides Radiation Protection Adviser services all over the UK and beyond, so we see a lot of roads (and a fair amount of sky when flying to destinations beyond the UK). Normally I fly to Scotland, but the annual Great North Run is an Ionactive drive (because of all the equipment I need), visiting four clients over 2.5 days taking in North Wales, South West Scotland, East Central Scotland and North Yorkshire.

X-ray Warning signs on x-ray equipment - Ionactive

The clients all use x-ray machines for quality control in the food and beverage industry. X-ray screening for food contaminants and for check weighing (yes you can ‘weigh' using x-ray technology), is becoming ever more prevalent, being driven by the major supermarkets. It was an enjoyable but extremely tiring few days.

Linac Bunkers

Ionactive Training Resource - Linac Bunker

In late September we were looking at linear accelerator (linac) bunkers as used in radiotherapy for the medical sector. I find this work particularly rewarding but always thought provoking. We spent the time performing critical examinations of key features of these bunkers, including radiation monitoring around the primary and secondary shields and at the maze entrance. We also check all the interlocks which are in place to avoid unplanned exposures to radiation. Thought provoking - since there is the separation between protecting staff and members of the public from ionising radiation, but at the same time (during the survey work) stepping aside whilst a cancer patient enters the bunker to receive a considerable dose of radiation for treatment purposes. Of course this is all a question of benefit and risk, but it can still seem rather odd. Someone rather special may well soon be treated in one of these bunkers - then it might seem odder still... (specifically because its likely to be one of the bunkers I have checked out!).

Onwards and upwards

So we move into October - a rather unexpected turn of events is currently taking place. I may well blog about this at some point, or maybe not, its early days. Suffice to say I do not see October being anything like September. I was due to spend a week in Dubai mid October that is currently on hold.

23/9/2012 - Three radioactive level gauges stolen and later found open

This is taken from the IAEA News Channel (Nuclear & Radiological Events)

Three radioactive level gauges stolen and later found open


[09 September 2012, Bulgaria, Devnya town , posted 17 September 2012, INES = 2 (Provisional)]

On 09.09.2012, the Bulgarian Nuclear Regulatory Agency (BNRA) received a notification for the theft of 3 level gauges from the Polimery JSC. Site, Devnya town. Stolen level gaugescontained Cs-137 sources with activity of 51.5 GBq each (calculated activity for the day of the robbery). The same day, the police found the source containers at a scrap yard, located closely. Containers were broken and the sources were missing.

Later, as a result of police investigation, the thieves were arrested and the missing sources were found, secured and put into a safe storage. However, source capsules were intact (not ruptured). Investigation showed that the sources had been dismantled and kept at the gypsy ghetto for a few days (two buried in the field in the backyard and one close to an open field WC).

Thirty five individuals living in the ghetto and that could have been exposed were sent for medical examination. Eleven individuals had blood samples taken and six individuals were admitted to hospital. Assessment of event consequences is continuing. However, up to now no adverse heath effects or abnormalities were observed.

BNRA in cooperation with the police and the national security service continues the investigation of event causes and circumstances. Preventive and corrective actions are being implemented to eliminate recurrence.

The incident log for the above event can be read at the following link: IAEA News Channel.

Ionactive Comment

This is the last thing we need - stolen radioactive sources. What is particularly worrying about this incident is that the source containers were not only stolen, but the individuals managed to extract the sources. The unshielded sources would not just be a hazard to the individuals, but could be used maliciously (e.g. as an emplaced source or even in a crude dispersal device "Dirty Bomb"). The report does not indicate if the individuals really understood what they were doing - i.e. were they deliberately trying to extract the sources for their radioactive properties?

The picture below shows a ‘typical' gauge which might be similar to those which were stolen. Two things to note here are a) they are very heavy (perhaps over 50 kg), and b) the sources are not easily extractable.

Cs-137 Radioactive Source in Gauge

For a totally unshielded radioactive Cs-137 source of 51.5 GBq activity, you would expect dose rates of 4.2 mSv/h. Whilst this dose rate is high by occupational standards it would not present a significant health effect for some considerable hours (assuming at least 1m separation). However, if this source were to be placed in the pocket then it would locally deliver a dose rate exceeding 40 Sv/h. Whilst unlikely to deliver a fatal whole body dose, it would certainly deal to a localised burn (after only a few minutes of localised exposure).

The report indicates that the sources were not damaged - hopefully they were ‘special form' meaning they will not disperse the physical radioactive material in all reasonably foreseeable events.


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This is the company blog of Ionactive Consulting Limited, a Radiation Protection Adviser consultancy. Visit here often to read our views on radiation protection and related matters. You can contact our director and RPA directly at

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