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10/12/2010 - Lost or stolen sources containing Co-60

This is taken from the IAEA event log.

Lost or stolen sources containing Co-60 (Poland) (05/11/2010)

(Note: the incident was reported to IAEA 08/12/2010)

 

During regulatory control carried out on in decommissioned old foundry facility located in LUBLIN (city located near the eastern border of Poland) regulatory inspectors of NAEA discovered lack of 7 lead containers (Type: PrJ20) with category 4 sources with Co-60. The lost or stolen sources contain Co-60 with following activity, on December 7 current year, as follow:

1. 9 MBq
2. 20 MBq
3. 20 MBq
4. 20 MBq
5. 13 MBq
6. 17 MBq
7. 17 MBq

The investigation is being conducted.

Please note that delay in the dissemination of the information to international community is due to clarification procedure. Information is sent as soon as possible after obtaining official data on missing sources.


The incident log can be read at the following link: IAEA News (You may need to log in as a guest).

This has already hit the media as well:

Radioactive Material Lost in Poland

Radioactive cobalt missing in Poland


Ionactive Comment

I certainly do not want to imply that this event is not serious, but it is not quite as big as one might expect. The serious bit is the actual loss or theft of radioactive material - the loss of control of such material is a serious management and regulation breach - in the UK it would certainly lead to prosecution and probably revocation of any permit to hold such material.

The key point here is ‘decommissioned old foundry' - it appears that this work has either not been controlled correctly, or perhaps the facility had been abandoned. Since the regulators (NAEA) appear to know they are ‘lost or stolen' then it is clear they were expecting to find them. Here in the UK we have been involved in a number of jobs where similar sources of much higher activity have had to be removed in a controlled fashion as part of decommissioning similar facilities (e.g cement works).

It is not entirely clear if these sources were part of process control or old industrial radiography sources (as one of the media stories suggest). It is likely they were radiography sources since the preferred radioactive source for process control is Cs-137.

It is likely that under the UK legislative scheme, these sources (assuming they are indeed Co-60) would be classed as High Activity Sealed Sources (HASS). HASS would apply to sources that had an activity > 4GBq when they were manufactured, and where decayed still have an activity > 100 kBq (the lower threshold is ridiculous in our view, but that is another story for another day). HASS sources are very tightly controlled and highly regulated (at least since 2005) in the UK.

Co-60

Ionactive Consulting Co-60 Gamma Decay

Co-60 is a beta / gamma emitter with a half life of 5.3 years. In terms of hazard, per unit activity, the exposure rate (dose rate) from Co-60 is higher than for many other types of radioactive material (indeed that is why it has been used in radiography, but less so nowadays). However, the activities quoted for this story are quite modest as illustrated below.

Dose rate (unshielded) from 20MBq point source at 1m = 6 micro Sv /h

To put that into context, take another look at our cosmic radiation measurements - this picture was taken at 37,000 above Manchester, the dose rate varies between 5-6 micro Sv/h (the monitor is not ideal for measurement of high energy radiations from space, but good enough for comparison purposes).

Ionactive Consulting - Cosmic radiation dose rate at 37,000 feet

So, to a good approximation the dose rates are similar for the circumstances explained. Now we can consider the dose rate if you got very close to the source (i.e. the 20MBq Co-60 source).

Dose rate (unshielded) from 20MBq point source at 1cm = 6o mSv/h

From an occupational safety point of view this dose rate, 60mSv/h, is much more significant. However, the data implies that handling the sources - even for a few minutes - would be unlikely to lead to deterministic effects (i.e. radiation burns to the hands and other extremities). Certainly, being very close to this source unshielded would not lead to whole body exposures causing deterministic effects (i.e. radiation sickness etc). In this regard it is important to distinguish the difference between this event and the event in Mayapuri involving orphaned Co-60 source.

That all said, and returning to our real concern already highlighted above, these sources were allowed to be lost or stolen. The activities could have been far higher and therefore the hazards to anyone who was directly exposed.

Dirty bomb material?

One of the media stories referenced has suggested these could be used as part of a dirty bomb. Generally Co-60, even quite old sources of this type, would not make a good dirty bomb. The sources are likely to be made of solid Co-60 metal, which would then be encapsulated in steel. Trying to blow one or more of these sources up with explosives would likely projectile them away, or at worst break them into large fragments. What it would be unlikely to do is to cause the dispersion of radioactive material far and wide (and therefore would not be capable of contaminating far and wide).

However, the media / public reaction to such an event is significant - something Ionactive has been saying for years. The radiological effects would be minimal - except perhaps for an unfortunate individual who has a piece of Co-60 embedded in them (but then they have much more serious things to worry about - like their limbs etc).

No, the real concern to us is how easy and ‘safe' these sources would be steal and indeed shield. They are in fact ‘too safe for their own good' (or ‘our good') - easy to steal and then use in some device (or just be left in a park somewhere). Let us emphasise again - it is the perception of what these sources might then do in a terrorist event, not what they will actually do (from a radiation effect perspective). For this reason the security of even quite modest sources (in terms of radiation risk) has to be paramount. Interestingly, this is not quite the philosophy of IAEA (and that comment is also for another day!).

5/12/2010 - Suspected radiation accident in a mine

This is taken from the IAEA event log.

Suspected radiation accident in a mine (Sweden) (02/12/2010)

(Note: the incident was reported to IAEA 03/12/2010)

 

Service personnel at Boliden Mineral may have been exposed to X-rays. Personnel from the Swedish Radiation Safety Authority are now on site at the mine in Gällivare to investigate the event.

On Thursday, 2 December, the Swedish Radiation Safety Authority received information from Boliden Mineral AB about service personnel at the Aitik mine in Gällivare possibly having been exposed to X-rays. Several of those involved have experienced nausea, which may indicate acute radiation injuries. The personnel are now undergoing medical examinations.

No risks are involved for the other employees at the mine or the general public. Boliden Mineral AB states that the equipment has been returned to normal production and is working normally.

X-ray equipment at mines is for example used for the analysis of elements.

The Swedish Radiation Safety Authority has launched a quick, on site investigation into the event. The Authority's personnel are on site at the mine in Gällivare.

Information about the event will be updated on the Authority's website, www.ssm.se


The incident log can be read at the following link: IAEA News (You may need to log in as a guest).

Ionactive Comment

Hmmm need to wait for more information on this one. Analysis of elements in rock etc would normally be done by a process of XRF. This would either be in the form of a lab based XRF machine or portable XRF. The lab based system is contained such that the x-ray exposure potential would be negligible.

A typical portable field based XRF system is shown below.

Niton XRF

This type of device would not be capable of producing the effects indicated in the above report.

More later...

20/11/2010 - Ionactive, the Great North Run and x-rays

Nope - do not want to disappoint anyone - this has nothing to do with running, exercise or similar. It is an annual road trip to the North of England and Scotland to undertake a load of client visits. If I am doing a single trip or meeting I will usually fly up, but with multiple meetings and lots of equipment the car is still better. The trip runs over three or four days and needs some logistics and understanding clients to ensure that all visits can fit into quite a tight time scale!

For this trip Ionactive has completed six client visits in three days. The work has been dominated by x-ray generators of all different types, configurations and uses - been really very interesting.

We started off from Reading on Tuesday morning (0430) and headed for the first stop in Seattle (Yorkshire country). From here we then headed up and onwards to Castle Douglas in South West Scotland. The views during the last 30 miles or so are fantastic. We ended day 1 by a final stop off near Falkirk. A long day which was finished off with a beer and a nice steak.

For Day 2 we spend most of the day in Falkirk before heading to Grangemouth in mid afternoon. From here we headed North to Aberdeen. This was supposed to be a 2.5 hour drive to the Hotel but it ended up taking 4 hours due to two separate accidents. It was too dark to take in any views but what struck me was the remoteness of some parts of the A90 - no light pollution, no cars, just nothing! Except of course during the traffic jams caused by the accidents where we all got out and stretched the legs. Anyway, finally got to Aberdeen ready for some rest - need to debate if I really need another steak and beer or not?

Two jobs done on Thursday it was then the epic trip back to Berkshire. Arrived back late last night after a 9.5 hour drive (actually took near 11 hours of actual time because I made myself stop for two breaks on the way). This is certainly not a regular occurrence and would normally prefer to fly, but the Great North Run demands a whole load of equipment including a Berthold LB125, LB124, SmartION.

Was also trying out a rather nifty new x-ray monitor, the Tracerco T406 - this was lent to me by the rather generous folks at John Caunt Scientific Ltd. It is an excellent piece of kit, measuring X and gamma radiation in the energy range of 17keV to 1.25MeV. I better not quote the price of it here - but suffice to say is really rather reasonable. I think a lot of users of x-ray equipment in the food industry will take note of this kit since it is easily cleanable and generally is a much better prospect than the rather old style Mini Type D etc. Will provide a review of T406 in a future post.

Background

One thing that has been interesting is to look at the ambient background gamma radiation dose rate - something we take at the beginning of any site survey. We have several instruments to do this, but for consistency on this trip we have used the Berthold LB 125 Gamma Spectrometer (but did compare to the T406 mentioned above). During the first visit (just North of Manchester) we measured an average background of 0.04 micro Sv/h. This is similar to what we would measure in the London area or near our own offices at Ascot. The measurement was taken at floor level and then at waist level - if there was a different we just averaged the value for the purpose of this exercise.

Moving on to Castle Douglas, which is built on granite, we measured an average background reading of 0.18 micro Sv/h. Aberdeen was less at 0.11 micro Sv/h which surprised me at first given that I assumed it is the ‘Granite city'. However, whilst not a geologist I took a sneaky peak at some geological maps and can see some sort of correlation going on here. The maps you see below are taken from an excellent page ‘Geology of Great Britain' by Ian West of Southampton University. I have made the images necessarily smaller to fit in the space below, but I encourage you to visit the page directly and have a look at this amazing maps. If you click on the images below they will also take you to the full map on the university website (opens in a new window).

First off Settle

Area around settle


Castle Douglas

Area around Castle Douglas

Then Aberdeen

Area around Aberdeen


For each map I have marked very approximately where I took the measurement. What is quite clear is that Settle was nowhere near granite, Castle Douglas was built right on the stuff, and my coastal location at Aberdeen also avoided direct lay down on top of the granite. So, this is not all that scientific but I do like numbers which appear to follow the facts - which is the case here. You can also see a similar pattern if you look at a radon map of the UK (see UK Radon website for details). I will be right down in Cornwall on Monday so it will be interesting to take some additional measurements and compare.

However, if you compare the radon maps and geological maps you will see that there is not always a direct correlation between granite and radon - or put another way, where there is granite you tend to get higher levels of radon, but in some places radon levels are still quite high even where the overlying geology is not granite based.

Ordinarily we would suggest that the differences in dose rate are trivial - (indeed they are in reality). The main purpose for taking the measurements is to check the instrumentation and provide a baseline ambient dose value for inclusion in visit reports.

However, recent media reports regarding the potential health effects from the use of back scatter x-ray systems brings the difference in background into sharp focus. An example of the reports we are talking about are here (Airport body scanners are 'just as likely to kill you as terrorist bombs'). (Incidentally, I will deal the the probability issues in the linked article later).

Pie and a pint, and a dose of ionising radiation Sir!

Pie and a pint, and a dose of 0.18 micro Sv in an hour

Let us assume for a moment that a single back scatter security scan yields an effective whole body dose of 0.06 micro Sv (this is an upper level estimate based on a survey of the literature). Now, let us supposed that I am at Manchester Airport and I need a flight which requires the use of this technology. I spend a few seconds in the scanner and I receive 0.06 micro Sv (remember - this is effective whole body dose). Let us suppose that I am not happy to receive the scan, I am worried about the radiation I will receive and that I am generally miffed and worried about the health effects. Now suppose that instead of taking the flight I instead decide to take the car and travel to Castle Douglas. I arrive at the destination and spend an hour at a local pub having a beer and a nice pie! During this one hour of indulgence I receive a whole body effective dose of ionising radiation which is equivalent to three scans of the security scanner at Manchester airport.

Should I by worried by this? After all, I have received three times the dose of ionising radiation that I would have otherwise received had I stayed at Manchester airport, undergone a scan and then got on a plane. Of course, I am ignoring the cosmic radiation that you will get in every hour that you fly, in the same way that I am ignoring the risk of a fatality (car accident etc) during the drive between Manchester and Castle Douglas in Scotland

The real point of this observation is that the dose from a typical scan from one of these back scatter security x-ray systems, is in the same ballpark as simply living in certain parts of the UK (i.e. within the region of varying background radiation around the UK). It really is that low. Nevertheless, the justification for use of these devices - i.e. the deliberate exposure of person to ionising radiation - is still a considerable debating point. What we must strive to do is to separate the politics and human rights issues from the science.

Backscatter x-rays - the risks?

The following is quoted in the above mentioned airport body scanner article: ' Peter Rez, from Arizona State University, said the probability of dying from radiation from a body scanner and that of being killed in a terror attack are both about one in 30 million, making body scanners redundant '.

I am not sure where they got the statistics from, so I am not going to argue these figures - they may be about right. However, there is one important difference between having an x-ray scan for your back and having a scan for reasons of security. When you have a back x-ray the benefit of that x-ray is explicitly yours - i.e. may identify a problem that can then be rectified with medicine. You have received a small dose of ionising radiation, and this may lead to a cancer in later life (but the risk is very low indeed and assumes that LNT is valid anyway). It can also be argued, but this may not be obvious to your personally, that society has also benefited - e.g. you are not off work, and they may have caught an illness early which ultimately means you do not need more expensive treatment at some later date. That said, the connection with society and any benefit to society will not be that obvious to you.

However, turning to the security x-ray, things are different. I would argue that you personally do not benefit from the scan that you have. This makes some people uneasy when looking at justification and benefits vs. risks. However, what is important to note is that the other 200 passengers on your flight have personally gained from your scan. Yes, that small 0.06 micro Sv (or thereabouts), that you could have gained during 20 minutes in the pub at Castle Douglas, has created a net benefit for those other 200 passengers. Furthermore, you benefit from each and every one of the other scans that are performed on all the other passengers. The benefit, as seen from a society perspective is much more obvious - as you sit in the aircraft ready for the flight.

Therefore, it is too simplistic to simply compare a derived cancer risk from a single personal scan with the probability of a terrorist event.

13/11/2010 - Open top industrial radiography and other matters

Industrial radiography radiation protection training resource

Industrial Radiography Open Top Bay - new resource!

The main feature of this blog article is to ‘out' some new resource that has just been produced for us by the ever innovative Grallator Limited. The original version of this resource was created by Ionactive / Grallator Limited for one of our clients. That resource is personalised for the company and will feature in awareness training sessions. The resource you see below is a sanitised version with all the good juicy stuff but without the personalisation.

Ionactive was involved in the creation of the bay - working in conjunction with an excellent Project Manager and local building firm. The bay was designed for a specific purpose so some features are not necessarily ideal for all open site radiography. For example, if you were radiographing smaller items, but still needed open bay conditions, then you would make the bay physical smaller and the walls higher. However, for the work in question which involves long pipes weighing several tonnes, what you see is an optimised approach (following the ALARP principle of as low as reasonably practicable). An important point to note is that without this type of bay the work would follow ‘site radiography' conditions requiring evacuating a large area of site, putting up barriers and generally causing interruption to the normal work flow.

The ratio of wall height to area of the bay was investigated using the Groves Micro Sky Shine computer code. It was amazingly on the ball, predicted likely sky shine dose rates on the ‘safe' side of the bay to within plus/minus 20% in most cases. Before I prattle on anymore, take a look at the resource which is embedded below.



If you like what you see then you really need to get yourself over to Grallator Limited. Ionactive can supply some radiation protection know-how, but it is Dr Chris Robbins at Grallator Limited that does the clever stuff. Here is an example of something Chris has produced about the Endocrine system and Diabetes (under the banner of his sister company www.whylearnthat.co.uk).




Airport body-scan radiation

There have been a number of reports over the last week or so regarding the use of x-ray back scatter technology at airports. The TSA in the US are basically requiring that commercial airline pilots be checked using these scanners or go through quite an evasive pat down procedure. Naturally perhaps, the pilots and none-too-pleased. Two pilots unions, representing about 16,000 pilots, have urged their members to avoid using the full-body scanners - stating health concerns as a key reason. A typical report can be found here: Airport body-scan radiation under scrutiny.

I would like to think that the health issues are being used to support their cause, rather than this being a genuine concern over x-ray exposure. However, according to many of the reports it does appear that the health concern is real. One quote from the above noted reference states "If you think of the entire population of, shall we say a billion people per year going through these scanners, it's very likely that some number of those will develop cancer from the radiation from these scanners". This is technically correct if one considers the LNT model of radiation exposure at low levels to be true (something that is currently up for debate). However, we must consider that the exposure per scan is in the order of 0.06 micro Sv, whereas a typical dose rate at 37,000 feet might be of the order of 5 micro Sv/h.

So, not withstanding energy and dose rate considerations (something to be discussed in a future blog), a significant proportion of the billion people who undergo the scan will then receive orders of magnitude more dose from the flight. There are some exceptions (e.g. ground staff who are scanned), but even these ‘occupational' exposures are trivial compared to other sectors of industry who use ionising radiation. Furthermore, even if LNT is to be believed, the use of Collective Dose to estimate risk in a future large population for planning purposes has been rejected by the latest ICRP recommendations.

During some of my business flights I have questioned the cabin crew and flight desk about cosmic radiation - I was surprised (or perhaps not?) to find a degree of ignorance. If my small sample is indeed reflective of a wider picture, then small wonder there are genuine concerns over these scanners!

For this reason we are about to work with Grallator and commission them to produce some specific resource on Cosmic Radiation - a significant proportion of this will look at radiation doses in the air travel sector - look out for it soon!

Flying

White Waltham where I am learning, try to gain a PPL

Well I am still heading towards a PPL but it is going to take a lot longer than I thought. It just proves that it does not matter what you have in your head - it is how you use that in a practical way (i.e. control the aircraft). I understand 'how to fly', but at the moment that does not help me 'to fly'. Ho hum ...

23/10/2010 - Radioactive Sharp Waste Hurts - and other mutterings

Sharp Radioactive Waste

No particular reason for this blog title, other than the fact that I came across this rather fetching sticker attached to a radioactive waste drum during a clearance monitoring session last week. There is something about these old images that is rather endearing - almost comic book in character but still getting the message across.

The image shows an operative in a windscale-suit / frogging suit (or whatever other term you want to apply to it). This is essentially an all-in-one plastic protective suit which is fed air from the back so that it inflates. This ensures that air is always going to ‘leak outwards\' if the suit is punctured so ensuring that potential radioactive contamination cannot enter.

In my early days of radiation protection I had the opportunity to wear these on one or more occasions and the experience was not great! Not only is it hot and sweaty, but it is noisy and clumsy and anything free inside (such as a small speak of cleaning material) buzzes around the head in the most annoying fashion possible)! That said, the reliance placed on such protective gear is paramount - especially when working with nasty alpha emitters. In actual fact the suits are not that different from the modern CBRN / HAZMAT protective suit (gas tight suit) - although these generally have their own self contained air supply and are made of more robust material.

The detail in the picture is quite accurate - for example, if you look carefully you can see a white cross shape in the tummy area. This is actually sticky tape that is attached to the suit once it is inflated - the idea is to tuck bits of the suit in so that it does not blow out too far in front of the individual - if it does then you have to constantly gather it in so you can see where you are going - this can be tiring.

The other historical classic image is the blue film badge attached to the inner clothing - have not seen these in the flesh for some years!

The couple of YouTube videos below show examples of this type of protective gear in action.

Breaking up the thorium plant at Dounreay




Dismantling the Pulsed Column Laboratory at Dounreay



Here is a larger picture of the classic film badge opened up. Many years ago I had a summer job where I had to add the name / badge code to the film that goes inside the holder. This was done on an old imprint machine - you had to rotate the dials to select the correct number / characters, place the film in its protective light package underneath, and then pull a handling to imprint the number.

All very antiquated - I wonder if many still use this technique today?

Film Badge


Here are a couple of other classic radiation / nuclear safety signs / posters:

Radiation Protection Poster


Radiation Protection Poster

The above poster is so true - but it is a sad fact that all too often ‘radiation' and in particular ‘nuclear' these days is feared but not respected.

Spending review / Radiation Protection Training

So, we have seen the Government Spending Review - clearly this will affect us all too some extent on a personal level. From a company (Ionactive) perspective, we are interested to see how this might affect the public sector training requirements - particularly with respect to radiation protection training requirements in the Police / Fire and Rescue Service arena.

Since 2008 we have been heavily involved in CBRN (The R & N in CBRN) training for the UK Police / Fire and Rescue Service. Certainly our bespoke CBRN courses are the best value available in the UK - this has certainly been indicted by Ryton. But that endorsement that alone does not guarantee future courses - we shall see what the next few months bring.

Public spending aside, over the last two to three months we have seen a dramatic increase in number of delegates for our monthly RPS training courses. About 50% of this increase has been from the UK, whilst the other 50% has been from non UK entities. Indeed, Ionactive fast appears to be coming a representative of the 'UK Radiation Safety Regulatory Framework' and therefore a key training provider of radiation protection services that meet UK best practice. Many of our foreign clients have explained that being trained to UK standards is the ultimate goal to achieve best standards in radiation protection in their own locality.

 

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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 mark.ramsay@ionactive.co.uk

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