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22/1/2010 - Overexposure in the field radiography



(New resource for Ionactive Radiation Safety Training - see further below)


This is taken from the IAEA event log.

The Incident - Overexposure in the field of radiography (27/07/2009)

(Note: the incident was reported to IAEA 20/1/2010)

 

(Poland). The incident happened during radiography work with Gammamat model TSI-3, containing Ir-192 source with activity at the time 2.6 TBq (70.2 Ci). The technician operating remote crank mechanism was not able to crank in the source to the shielded position. He asked for help company’s radiation protection inspector (RPI).

The RPI with the second worker came in the hurry, forgetting to take their individual dosemeters. The RPI had taken his own decision to return the source to the shielded position by manually grapping the guide tube and force the source to move to the shielded container. The source was returned back to the safe position.

The incident was on July 27th, but information about it was released by the company on 28  September, when the radiation burns of RPI became advanced [Ionactive emphasis]. The National Atomic Energy Agency (NAEA) Regulatory Inspectors  investigated the incident in October and finished it in December. There were no doses obtained by the public.

The doses of the workers were assessed on the basis of blood test (biodosimetry) and reconstruction of the event was based on the statements of involved workers. The doses of RPI were approximated as: whole body dose 365 mSv and externity effective [Ionactive: probably means extremity / equivalent dose] dose about 5 Sv. The doses of second worker were assessed by biodosimetry examination as whole body dose 182 mSv and externity dose about 2,3 Sv. The blood tests were performed by Central Laboratory for Radiological Protection in Warsaw from blood samples taken at the beginning of October and repeated at the beginning of November. 


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

Ionactive Comment

Oh dear ... first recorded event of 2010 (incident was in 2009) and it is industrial radiography again. What sets this apart from some of the other incidents is the person exposed was the very person who would be relied upon to do the right thing (i.e. the company radiation protection inspector, or RPI).

As always, we do not have all the facts here - so this comment and analysis should be used for general interest / educational purposes.

Looking at the Polish National Atomic Energy Agency Atomic Law page it appears that the RPI is actually the Radiological Protection Inspector (at least defined more recently, since the initial Atomic Law Act came into force in November 2000 and there have been several amendments since). From what I can gather the RPI should meet the standard of a Qualified Expert (e.g. as define in the EURATOM Basic Safety Standards), which in the UK is Radiation Protection Adviser (RPA). Suffice to say, the RPI is (or should be) the person relied upon by an organisation using ionising radiation sources to give suitable and sufficient advice - and mostly certainly in an incident situation provide advice to minimise exposures!

No dosimetry

The report notes that the RPI (and second worker) arrived in a hurry and did not have their dosimeters with them. What is not clear is if the dosimeters were active (i.e. real time dose alarming etc) or if they were passive. If they were passive (e.g. film badge or similar) then they would have provided no clue to the actual radiation fields that were being experienced. If they were active then at least they would know (one would hope...) that significant radiation dose rates existed and take appropriate action. However, in this case no dosimetry was worn so no early warning could be given - neither could a direct assessment of exposure be made (resorting instead to blood assessment and incident reconstruction).

No workplace dose rate monitoring

What is not specifically mentioned, and therefore we have to assume was absent, is any form of workplace / field monitoring (i.e. dose rate instrument). As this was field (i.e. site) radiography it is really quite disturbing that a dose rate instrument was not available for use. If it was available (but not noted in the report), and indeed used, then either it did not work or was off scale - but in any case any information it might have supplied was not acted upon by the RPI or other workers.

Dose Rates from Ir-192

The dose rates from an exposed and un-collimated 2.6TBq Ir-192 source at the following distances are as follows 118 Sv/h (5 cm), 29.5 Sv/h (10 cm), 1.2 Sv/h (50cm), 294 mSv/h (100cm) and 73 mSv/h (200cm). These values should be taken as approximate and have been rounded. We can see that by any standard the dose rates are considerable and no person, even in an incident recovery situation, should be exposed to these levels where deterministic effects are possible.

At 5 cm from the source the dose rate is near 2 Sv/min - therefore I think it is unlikely that the RPI grabbed the source or came any closer than 5cm from it (thankfully!!). Clearly the inverse square relationship is unreliable very near the source, suffice to say that one would be looking at perhaps > 1 Sv/second very close to it. Whilst the interpretation of extremity dose in the report is not clear, I believe it to mean 5 Sv to the fingers or hand - if that is so then it supports the view that the source was never held directly (or placed closed to the hand). The generally accepted threshold for deterministic skin effects are 3 Gy - clearly this was exceeded and I do wonder if my own interpretation of the report is correct since ‘radiation burns .... became advanced' might imply a substantially larger dose (e.g. Temporary Depilation, Permanent Depilation and Desquamation appear progressively in the range of about 4-20 Gy).

With respect to whole body effective dose, the report claims an exposure to the RPI 365 mSv. We have no information about how far away he was from the source, but it is probably unlikely that the individual worked around the source for more than a few minutes. He would need to have been close enough to the shielding container in order to feed the source back in - perhaps between 10-50 cm away. Therefore his resident time of exposure (assuming his body is static) might be somewhere between < 1minute up to perhaps 18 minutes. The same could also be said for the second worker who was also exposed (182 mSv effective whole body dose).

Was the RPI suitable?

Whatever the true turn of events, both individuals must surely have known the risk they were facing - or did they? I would like to think that any qualified (certificated) RPA in the UK would be able to handle this situation in a safe manner following the ALARP principle (as low as reasonably practicable). However, the UK recognises the concept of ‘suitable RPA' - that is a RPA who not only satisfies the core competence requirements to be a RPA, but also shows they have suitable and sufficient experience in a particular area of radiation safety. Therefore, for example, it might be the case that a RPA who only works with x-ray systems might not be competent to advise on the use of unsealed radioactive materials. However in this particular case, would a RPA with no experience what so ever make the same mistakes as appears the RPI did? I would like to think not - but the question still remains, was the RPI suitable to advise on this area of work (or indeed actually physically move the source?).

What about contingency

Notwithstanding the suitability or competence of the RPI response to the incident, a question is also raised regarding contingency. There does not appear to be much evidence of any contingency plan - particularly since a failure of the source to retract is clearly reasonably foreseeable. One wonders why they did not move to a safe distance and ponder their next move if such a plan was lacking. Or indeed, was a plan actually in place, but was then not followed? These of course are questions that we cannot answer and it is best not to take the assumptions any further. What is clear is that the job must have been badly planned and not supervised by a competent person. It goes without saying that an event such as this is the UK would bring out the HSE in force.

Regulator Notification

Talking of regulators and notifications, the incident appears to have been compounded by a rather casual notification. The actual incident took place on July 27th 2009, but information was only released by the company on the 28th September 2009 - presumably to the National Atomic Energy Agency (NAEA) Regulatory Inspectors. What is shocking, but may only be implied by the way the report is written, is that the notification appears to have been prompted by the radiation injury rather than by any standard protocol (‘...when the radiation burns of RPI became advanced...').

This is clearly another case study in how not to undertake industrial radiography.

As we have mentioned many times before, site (or field) radiography can be undertaken completely safely with the right people, following the correct procedures and best practice in radiation protection. However, where possible such work should be conducted in an enclosure - i.e. ‘enclosure radiography'.

Which brings us nicely on to some new resource....

Open top industrial radiograph bay - fly through

We have two projects on the go at the moment - both being undertaken by Grallator Limited. The first of these, a fly around and inside a medical radiotherapy bunker has already been partly featured in an earlier blog. This medical resource will be uploaded once an audio track has been added.

The second project is in our opinion very impressive indeed. We have commissioned a fly around and inside an open-top radiography bay. The aim of this resource is two-fold. Firstly it will be used (in a slightly altered form) by one of our clients to provide awareness training to factory workers who will be working around the bay (but not involved with radiography). The fly around highlights key safety features like the emergency pull cables, the gate interlocks, and external operating panel and warning lights. The second aim is to highlight sky-shine / scatter (or rather lack of) in the areas where the factory workers will be based. It will also show why working above a certain height within a certain distance from the bay is prohibited.

The resource is still in the early stages but I am grateful to Grallator for letting me have these test renders. I think you will agree that the detail is very impressive. First, take a look at this video interlock test sequence - neat!




What follows below are some static render test shots.

The radiography bay locking system




The radiography bay control systems and warning lights

 

 

Check back often for the latest news on this new radiation safety resource.

Also check out Grallator Limited too.

 

16/1/2010 - A is for Atom (with Dr Atom)



Came across this earlier today - some vintage animation on the atomic age: ‘A is for Atom'. For those that follow Ionactive closely you will know we have some excellent video resource produced for us by the ever innovative Grallator Limited. You can see this resource in two places: either visit our Ionactive Video Resource pages or have a look at our YouTube IonactiveConsulting Channel.

However, spare a thought for those that knew the science (well some of it), but did not have access to the types of computer technology that we might take for granted today (i.e. when producing radiation protection resource).

‘A is for Atom' was sponsored by GE (General Electric) in 1953 and produced by John Sutherland. The animated film is a real period piece and the narration is just what would be expected from the 50's!

The resource introduces Dr Atom (see above) who explains the structure of the atom and how these make the elements (with the possibility of many isotopes). Dr Atom then explores the history of atomic energy (up to the 50's of course!), looking at nuclear fission (power production and nuclear weapons). Some wild ideas like nuclear powered planes are discussed as if they might be just around the corner (if only they knew!).



Enjoy!

A is for Atom Part 1




A is for Atom Part 2

9/1/2010 - Radiation and Risk Perception

In this blog article:

  • Frying travellers with x-rays
  • Simon Jenkins (Guardian) article (proliferation of nuclear panic)
  • Prof Wade Allison (Radiation and Reason)
  • Greenpeace
  • Added 11/1/2009 'Irrational fears give nuclear power a bad name'


It's like waiting for the bus, you wait for ages and nothing arrives, and then several come at once.

This blog article has been updated (11/01/2009) to acknowledge another new article in the Guardian ‘Irrational fears give nuclear power a bad name, says Oxford scientist'. I have left main body of this blog entry as it was, but have inserted some new comments at the bottom in relation to this latest article.


Well that was the week that wasn't as far as Ionactive is concerned. Whilst we only had two planned visits for the first week of 2010, one visit was to deliver some bespoke Radiation Protection Supervisor (RPS) refresher training to a company in Hull. As always, bespoke training takes that bit more planning and effort - to have all the newly created folders in the car boot and ready to go on Tuesday, and then for the snow to arrive, is a real bind.



The training was based around NORM (Naturally Occurring Radioactive Materials), or to be more precise TENORM, where TE means Technically Enhanced.

Radiation matters in the media

The general subject matter of this training course could not really come at a more opportune time - especially as ‘radiation matters' have been in the news of late. For example, x-ray security scanners for whole body surveillance at airports have been in the media. The two main issues raised seem to be ‘human rights' (modesty ?) and radiation safety. With respect to radiation safety this has been split between media articles that report (generally) that there is nothing to worry about, and the more fringe groups (civil rights?) who claim that these machines will lead to cancers, DNA damage and similar.

The problem I have found with some of these groups is that there appears to be no element of listening to reason or even simple debate - most who write articles such as 'Full-Body Scanners to Fry Travellers With Radiation', and the many who leave comments, are very fixed in their views.

You will note we have left comments on the article under the name ‘Mark'. The thing is, I do not deny that currently radiation protection is based on the assumption of a direct linear relationship between radiation dose and effect with no threshold. This relationship, a stochastic effect based on probability, is the corner stone of the International Commission of Radiological Protection (ICRP) and forms the basis of ALARA (as low as reasonably achievable) internationally, which roughly translates into the UK concept of ALARP (as low as reasonably practicable).

The very negative views in the above article say again and again words to the effect of (and I quote an example here) ‘Every little hit has the chance to cause a cancer. Adding to the overall lifetime ionizing radiation load to every traveler (old and young people are more susceptible to the dangers) without knowing that there is a real upside is crazy'. I have no concern about the general anxiety regarding the usefulness (or otherwise) of x-ray screening (to avoid more exploding underpants) since there is likely a good debate to be had (and I am not a security expert). I do however worry about anxiety based around receiving such a trivial dose of ionising radiation.

Radiation Risk - seeing the Wood for the Trees?

The problem with the example response quoted, and there are many similar ones, is that they cannot see the wood for the trees - even when one tries to show them the picture as clearly as possible. In one of my responses, and featured in a recent blog entry below, was an example of a radiation detector showing the dose rate at ground level and the dose rate at 36,000 (I note that the monitor is not a great choice of instrument for natural cosmic radiation - but it is a good relative comparator).

In a reply in the above mentioned article I point out that my example dose rate (at 36,000 feet) would yield a radiation exposure over a period of less than one minute, which would be comparable to what you might receive if you were to be scanned by an x-ray back scatter unit. The point I made here was not acknowledged or accepted - just the same negative points coming across.

Why is that? - is radiation really that scary to some people - even though they accept (or maybe they choose not too) that they receive doses of natural radiation far higher once up in the air than they would from the artificial (electrically generated) security scan. In addition, and related to my NORM training mentioned above, they are also exposed to radiation exposures on a daily basis which are orders of magnitude higher than a typical back scatter x-ray scan (or set of scans).

In my view this is about civil liberties (whatever that really is) - and I really do think the ‘radiation scare' is used as a convenient excuse - I cannot think of another reason, especially when you are faced with the facts regarding relative exposures from the scan vs exposures once up in the air.

Simon Jenkins of the Guardian

Then an article crops up that turns things all around (as far as the media is concerned) - ‘The proliferation of nuclear panic is politics at its most ghoulish' by Simon Jenkins of the Guardian. The article is interesting simply because it takes a different perspective - ‘The risk from radiation is exaggerated. Worst-case scenario fantasies are used to justify wars that cause many more deaths'. I'm not convinced that there was enough due care and attention in the article (or perhaps Simon has just not read both the books he was advertising). In addition, I cannot really buy into the view that nuclear weapons are not such a big deal (my emphasis). However, the article still has many comments (we offered one) and it is generally pleasing to see that the quality of the responses are better than achieved on the previously mentioned ‘scanner frying' website.

The credibility of the article is somewhat diluted, I think somewhat unintentionally, by the insertion of sentences that might have journalistic merit (adds to a good story) but are in no way related to the topic or science. For example  ‘Only yesterday research suggested that mobile phone radiation may relieve Alzheimer's' - Simon may or may not know that when discussing mobile phones we are talking about micro waves, part of the electromagnetic spectrum and a form of non-ionising radiation. The radiation issues discussed by the authors quoted by Simon are clearly ionising radiation related.

Prof Wade Allison - Radiation & Reason

Simon introduces two authors in his article: Prof Wade Allison (who discusses ‘obsessive safety levels governing nuclear energy') and Prof John Mueller (who looks at the ‘toxic fear associated with radiation from nuclear weapons'). In this blog article I am really looking at Prof Allison's area of interest.

In Simon's article he notes that ‘Allison analyses successive studies into the only serious nuclear accident since Hiroshima, the Chernobyl fire, which killed no more than 60 people, all in close contact with the fire'. This statement may or may not be true - but there are two sides to every story are there not? I make no secret that Ionactive is generally ‘pro-nuclear' and pro-radiation (in terms of the use of ionising radiation for the benefit of mankind). However, it is not reliable to avoid mentioning those that believe the Chernobyl story to be very different.

Greenpeace - Chernobyl death toll grossly underestimated

For example, take the 2006 story from Greenpeace ‘Chernobyl death toll grossly underestimated'. This report claims that  ‘the full consequences of the Chernobyl disaster could top a quarter of a million cancer cases and nearly 100,000 fatal cancers'. The full report can be found here.

Interested readers might also want to look at the UNSCEAR Chernobyl Reports.

Just as I claimed elsewhere (see below) that Prof Allison's book is a good read and well written, I equally can claim the same for the Greenpeace Report. Here then is the problem - which is right? I'm not sure because both are based on the analysis of a significant set of data, and the answer you get may depend on what data you use. Let me use an abstract example to show you the way I am thinking (this also appeared in the media this week): Ancient Woolworths sites.

'Wood for the trees' again?

The Woolworths article written by Matt Parker takes a slightly sarcastic (but entertaining) look at the geographical spread of the famous (now defunct) store across the UK and shows that by being rather ‘selective' with the data (!) you can illustrate some interesting patterns - e.g. Woolworths hunter-gatherer tribes use them in the early days to do their shopping! Of course if you read the article you will see the author was responding to another (serious) investigation into similar patterns in prehistoric monuments across the UK.

Parker concludes that ‘in any sufficiently large set of random data it is possible to find meaningless patterns of any required accuracy'. Ok, so returning to Simon Jenkins article, and specifically my comments relating to Allison vs Greenpeace, I hope you see where I am coming from - the point being that you can use selective data to drive the outcome you want. In saying this I am not claiming that Allison or Greenpeace have deliberately done this - but I think the desired outcome can drive the selection process whatever anyone says (‘wood and trees' comes to mind again!).

I do think this claim can be made directly against the article written by Simon Jenkins - in my view he writes as if he has made up his mind or he is endorsing the books he has read (or partly read). If we really want a serious debate on this issue then all interested parties and research must come together. This is where I agree with Simon where his article headline states ‘politics at its most ghoulish' - but perhaps for a different reason. In my view politics, livelihood, regulators, contractors etc do have an influence on all this - but it is an influence that affects both sides of the argument - not just one side. This is the problem with Simon's article, Prof Allison's book, the Greenpeace report and even the ‘frying traveller' article I first started with.

Returing to Prof Allison - Radiation or Reason



I have the book - Radiation and Reason by Prof Wade Allison. It is a very good read, I do not agree with all of it, but it is very well written and mostly against the grain of current international opinion (by this I mean ICRP, since there are many smaller groups who will argue on the same side as Prof Allison, as well as some who will very much argue against!).

Regardless of my opinion on Allison's conclusions, and I will provide a blog review of these as time allows, he does explain the concepts in a very readable form. For those that might want to dismiss his thoughts - they really should do the decent thing and read it first. Indeed, the same advice should also be accepted by those that might want to discredit the work of Greenpeace - go and read the above mentioned report first.

I would love to put Prof Allison in a room with our ‘Frying traveller' writers and see what happens!

Irrational fears give nuclear power a bad name

And so the Simon Jenkins article kicks off a debate - or is it really a debate? A new article has appeared in the Guardian ‘Irrational fears give nuclear power a bad name, says Oxford scientist'. You know what? - the title ruins the article in my view from the very start - and that is completely compatible with what I said in my above blog article.

Here is what I said this morning (comments left on the Guardian website, 11/1/2009)

I think the comments so far fit into the expected patterns:

Some agree
Others disagree (probably the majority?)

Many of the responses move into areas of nuclear power, cancer clusters etc. You also have the responses from some of the establishment (HPA) and areas of academia (Richard Wakeford). The said responses are entirely as expected as I discussed in my blog on the recent Simon Jenkins article here:

http://www.ionactive.co.uk/blog  

The problem I have is what exactly is the point of this article? Have the authors read the book by Allison from cover to cover? Have the responders (particularly the 'experts')?

I believe that Allison does raise some important issues. I say this as I have read the book. I do not agree with all of what is being said, but significant elements are quite plausible. I also say this as a Radiation Protection Adviser, so if someone wanted to see what camp I am in, then I am in the business of 'protection'.

Other than encouraging people like me to make comments, this article will only work (in reality) if it encourages those that are interested (both casual observers and 'experts') to go and READ THE BOOK. As a readable resource I have to say that Allison has done an excellent job.

In this world of instant online articles and information readily available at the click of a button I think most people want things in 'black and white' , a subject or article which is easy to compartmentalise. This subject is not that as noted in my above mentioned blog article.

6/1/2010 - The Ramsay family in the snow



Curse the snow etc! I know the kids love it and they have a day off school, but it has really put a spanner in works regarding Ionactive's first full working week in 2010. We were supposed to be delivering a bespoke RPS course for users of Naturally Occurring Radioactive Materials (NORM) up in Hull.

All the training material had been prepared, as had the presentations. However, despite reviewing the weather constantly it was a ‘no go' - it was simply not safe enough to undertake a 400 mile round trip by road in those conditions. Furthermore, I'm not sure I would have even got out of the drive way - as you can see from my car picture above.

So have been doing office work at home - but also spending some time with the family. This afternoon we realised we needed some food - like something to eat for dinner. So we set off on foot to the small local shop to see what we could find.

It is amazing what you can do with a tea tray and a piece of rope. As you can see here, Ben is really enjoying the ride, it was indeed the only way he could get around as the snow was up to his waist in places.



Alex my older Son also wanted to have a go so he got on as shown below - as you see Mrs Ramsay is doing all the hard work, Alex is much bigger than Ben!


 

Not to be outdone, my wife also wanted a go. Despite the obvious low coefficient of friction, we clearly had some engineering problems as the tray refused to budge!

 

 

When we got back I worked with Alex to build this chap below - it's bulk somehow modelled on Mr Ramsay (so I am told).



Ok, so not the day I expected and I very much dislike letting clients down. However, I am safe and so is my family - it was the right call I believe. Now hoping this horrible white stuff swiftly melts, but I fear that is not going to be the case!

31/12/2009 - Security back scatter x-rays

This very quick blog entry was initiated by my reviews of the media and their anxiety over x-ray exposure for security purposes before flying.

I do not have time this morning to write much, but I know a load of Twitter followers might be interested. So here are two pictures of a radiation dose rate instrument - one at ground level and the other at 36,000 feet. For the experts that might be reading this, I know we are looking at muons (and their family), I am not monitoring for neutrons, and the detector shown is not ideal for this type of measurement. That said, it is a good indicator and gives a good relative reading.

Radiation exposure at ground level


The value above would vary between '0' and 0.5 μSv/h (i.e. background).

Radiation exposure at 36,000 feet


Comment

A back scatter unit will typically look like the following:


A typical security back scatter x-ray machine will deliver an exposure to a traveller of about 0.06 μSv (and less than this most of the time). Once that person gets in the air they are exposed to a dose rate of something like 5μSv/h (this depends on height, latitude etc etc). So we can see that it would take about 43 seconds of flight (once cruising at 36,000 feet) to receive a similar level of radiation as would be received during the security scan.

The media does not appear to say a lot about this.

I wrote a bit more on this in an earlier blog here.

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