Is there any data available for potential exposure (#unexpected exposure) in the occupation of radiation facilities( non-nuclear facilities) like industrial radiography, food irradiation facility, radiotherapy etc.
I want to compare my data with some of the study resulting in the probability of potential exposure in above facilities. OR please give reference for the data for probability of accident in above facilities.
@ Thomas Adejoh, any data will be helpful either potential occupational exposure, potential public exposure or potential exposure to both
It is very difficult to give a general number, even by categories of application. The potential exposure will always depends on the radiological protection measures and on how the procedures are respected.
Public exposure should be totally excluded, except for exceptional accidents like the pne in Goiania, for instance (if you Google it you will find the IAEA report on it). Personnel exposure will depend on the safety culture of the organisation. One example of accident in the industrial radiography (it reproduces a real instance): the warning signals that indicate that the source is not in the shielded position malfunction and the source remains out in an unshielded position, yet undetectable to the naked eye. The workers enter to inspect the pipe and to do other work, but they do not wear the compulsory PADs so they have no idea the source is still in exposed position. As a result, a number of workers were exposed to doses between a few 10ths of mGy to a 1-2 Gy. The accident would have been easily avoid if the workers would have worn the PADs or the RSO would have inspected the site prior to allowing the workers in.
In theory the procedures were there, and the accident had a close to 0 probability but, because nobody followed the rules, it happened.
To conclude, it is hard to pin a number on situations that depend heavily on human behaviour,
The attached document prepared by IAEA on Lesson learned from major radiation accidents (doses received by victims are also mentioned) may be helpful.
If I remember rightly, since a few years the INES criteria are also applied to accidents and incidents in radiation facilities. So you should find at least some data in the INES database at IAEA.
The German cases, however, are reported on the annual reports of the federal agency for radioation protection (Bundesamt für Strahlenschutz). Some excepts might be available in English, but I am not sure. www.bfs.de
Indeed, all serious radiological incidents, either from industry or medical field, are documented and then IAEA issues a report on it. You can find these reports (which are freely downloadable) at http://www-pub.iaea.org/books/IAEABooks/Publications_on_Accident_Response
Thus you will see what instances lead to the accident in each case. Stil this does not mean that you will get an answer about the probability of an accident / incident happening. This will be strongly dependent on how the radiological protection system is built in each case and how do people comply to those procedures.
Thanks everybody, but my query is still unsolved.
Although we have scattered data of incidents/accidents from different sources, but this is of no use for probability calculation unless we know the total number of operations and/or total number of operating facilities in a specific time period.
Alok, this is what I was trying to explain: a general number for such a probability does not make sense. Each facility is different and the probability of an accidental exposure only makes sense for one facility at one given time. For instance, let's say you visit a shipyard where industrial radiography is used. You will study the work safety procedure and identify some flaws that escaped the RSO / HSO. This will give you a first probability for accident. Then you study the work habits and observe how the workers comply to the regulations. This will give you a second probability number. These two together will give you the probability for an accident, valid for that site at that time. Based on your findings, normally the HSO / RSO will improve the procedures and educate the workers as to lower the probability. So, next time you go there, the probability will be different. And this goes for each site: in order to have a meaning, you can only have a probability for a certain site at a certain time.
@ Raud, i was seeking some generic data specific to given practice and given country , i got one reference but searching for some more references to compare with.