Emergency Source Containers: What do the Regulations Say?
This article looks at a few of the issues relating to regulations regarding emergency equipment, in particular, emergency containers. The article looks at the clarity of regulations, equipment types, transportation and best practice.
Why do you need an emergency container?
As you are most likely aware, the IRR99 requires that an emergency container is on hand to facilitate the safe retrieval of a source in the event of an incident involving ionising radiation. The regulations state that contingency plans must be in place by the establishment in consultation with the RPA to resolve any foreseeable emergency. The regulations give a list of essential special equipment that must be available during an emergency and an emergency storage container is one of these items.
The regulations are clear, or are they?
The regulations are clear; each site must have an emergency container for radioactive sources used in industrial radiography. However where they are unclear is how many emergency containers you need. You must have access to an emergency container, however does this mean it has to be somewhere on the site where you can go and collect it if an emergency occurs? Another interpretation is that an EC must be part of your radiography kit and you must have it right by you when you are conducting radiography. The number of ECs owned by a company varies from one company to the next with some having just one for many sources in use to others who will have one EC for each source in use on site. It is often hard to tell how many sources a company may have the need for; sometimes extra sources are bought in, in order to keep up with the workload and therefore it is hard to predict how many emergency containers you require. In circumstances similar to these it is important to ensure the essential emergency kit (as stated in section 33 of Industrial_Radiography.pdf) follows the number of radiography teams, sources and containers you have in use.
There are many brands of equipment in use in Gamma Radiography and each has a different model of source pigtail. The emergency container you use should be able to be loaded with this pigtail allowing the radioactive isotope to be stored in the correct location. This is often hard to tell due to the age of some ECs in use but if you need a hand with this please get in touch and we can see if we can help. The other important property of an EC is the shielding used this is commonly lead however it could be depleted Uranium. The size and shape of this shielding could vary and most importantly this will affect the amount it attenuates the radiation by. There are no set regulations on how much the radiation should be attenuated to however typically the value of 2mSv/hr on the surface of the container is used.
If a source disconnect does occur how would you transport the source to a safer place? In most cases, the recovered source would need to be transferred to an appropriate transport container, adding complications in a retrieval situation and increasing the level of exposure. Using an appropriate EC with a transport certificate ensures a damage or suspect source can be transported off site for inspection at an appropriate location without the need for transferring the suspect or damaged source between containers.
Best practice is based on each team of radiographers having access to an emergency container in case of a source disconnect either right next to the radiography projector or in the van a short distance away. Having an emergency container very close to the radiography team ensures that if an incident were to occur, and there is no way of knowing when this would be, the radiation exposure as a result of the incident can be kept to a minimum. To implement this however can be very expensive. To meet best practice sites which currently operate with several sources but only have one emergency container may need to re-think the number of emergency containers they have.
The other side, Cost!
Working to best practice and creating the safest possible environment to carry our gamma radiography can come at a high cost. In today’s financial environment companies are looking at controlling costs while maintaining the highest levels of safety and sometimes these two aims don’t go hand in hand. As with many items of kit used in gamma radiography, there is an initial purchase cost and an annual service cost. An EC is an essential piece of kit helping to keep radiographers safe and any surrounding people however to comply with the IRR99 there is a reasonably practical test which can be applied. Your RPA should be able to help you conclude what is appropriate and safe for the number of ECs you have and use.
A Safer Way
A safer method would be to use an emergency container that is Type A certified such as our EC2, EC3 or EC4. This allows the EC to be transported when loaded and taken to a safer environment. Not all emergency containers are classed as Type A packages, so be careful to note which ones are when purchasing one as this should be a deciding factor. “An important factor for us was to create an emergency container that can help minimise the radiation dose received in a potentially dangerous situation, that’s why our EC2,EC3 and EC4 are Type A certified so that radiographers don’t have to increase their radiation exposure or risk of something else going wrong through having to transfer a suspect source to a suitable transport container” Chris Cole, Director of Gilligan Engineering and designer of the EC range.