If you’re not experienced in the implementation of radiation shielding rooms for your industry, trying to navigate how to construct a radiation shielded room can be difficult. As somebody who might work in the NDT, medical or academic field, you may not be familiar with all of the challenges associated with radiation protection, and that’s okay.
Constructing a radiation shielded room can be extremely expensive, and time consuming. That’s why it’s important to get things right the first time. One misstep can result in a longer project completion time and a huge hit to your budget.
In this blog post, we’ll be talking about some of the most common mistakes decision makers like you make when trying to build a radiation shielded room, and how you can avoid them.
Why is Radiation Shielding Important?
Quickly, let’s talk a little bit about why radiation shielding is so important. Calculated and accurate radiation shielding protects patients, clients, employees and the general public from an overexposure to radiation. Without it, your business may not be able to pass the government requirements to operate safely and this exposure could cause harm to those in the area.
As an RSO (Radiation Safety Officer), manager, architect, or general contractor, you need to realize that successfully constructing a high quality radiation shielded facility that lasts will take time, money, and a whole lot of planning. However, your investment will be heavily outweighed by the safety and durability benefits that result.
Keep reading to find out how you can avoid the three biggest pitfalls we see.
1. Putting the Cart Before the Horse
Okay, you might be a bit confused on what we mean by this. In our years of radiation shielding experience, the biggest issue we run into with our customers is that they design a whole facility that includes a radiation shielded room without first consulting a physicist to conduct a shielding study.
If this is the first time you’ve heard of a shielding study, you’re not alone! In the simplest terms, a shielding study determines the radiation shielding requirements needed for what the room is being used for. This means that 100% of the time, a shielding study is necessary to dictate the radiation shielding required to safely operate inside the room.
For example, when conducting a shielding study our physicists will look at occupancy outside of the room and how the radiation inside the room itself will be used. Our physicists will start by learning everything about the machine inside the room, how the machine is used, the state requirements, and other important variables. These factors (and more) will dictate what type of shielding materials will be needed and how thick the radiation shielding barriers will need to be.
In cases with different types of radiation, you may even need to use a combination of different types of materials like polyethylene, steel, high density block and lead as a part of your shielding plans.
To avoid the headache of making this misstep, simply make sure a licensed physicist is involved during any and all stages of planning for your project. This will ensure that you’re purchasing the right materials and truly constructing the solution that will best fit your business’ needs.
2. Planning for Penetrations
When looking at constructing a radiation room, another extremely important factor to consider is what penetrations you’ll be using. Penetrations can consist of things like HVAC, Ozone exhausting, wiring, cameras, sensors, and cooling lines needed for the machines inside the vault. Penetrations can come into a shielded room through the floor, walls and ceiling.
When a penetration comes into a radiation vault, you need to block the barrier behind it. For that reason, it’s important to plan where you’ll place the penetrations. Penetrations need to be coordinated with the radiation machine manufacturer to ensure a successful installation and most have an IDP (installation data package) to follow closely.
Just like doing a shielding study, you’ll need to do a complete design of your radiation room before you move forward in order to make your room as protective as possible.
3. Choosing the Right Shielding Materials
Picking the right radiation shielding materials for your radiation room all comes down to how radiation is going to be used inside the room and what the occupancy will be around the facility.
For example, if you plan on using concrete for shielding and you have higher energy radiation, thicker walls are needed. When extra thick concrete is required, things become more technical and mass concrete procedures are needed.
The main characteristic that distinguishes mass concrete from other concrete is the thermal behavior from hydration of the cement. The cement-water reaction causes the temperature to rise within a large concrete mass, and where the heat is not quickly dissipated, can be quite high. This thermal behavior may cause a loss of structural integrity and cracks. The ACI 301 standard states that the maximum temperature in mass concrete after placement shall not exceed 160 °F and the maximum temperature difference between the concrete center and its surface shall not exceed 35 °F.
Sensors are installed to monitor these temperature differences and methods to control the concrete temperature are put into place. This will reduce the risks of thermal stresses and cracking in the concrete.
On the other hand, choosing a different material like lead in place of concrete may be easier to construct and take less room, but your budget will have to allow for a more expensive solution. You also have to consider the environmental and safety factors.
When it comes to choosing materials for radiation shielding for your facility , the best thing you can do is work closely with an experienced radiation shielding company and a licensed physicist that can help you through the process. Find the solution that’s a good fit for your timeline and budget, not just one or the other.
Constructing a radiation shielding room may be intimidating at first, but it doesn’t have to be. By making sure that you choose the right materials, conduct a shielding study, and plan for all penetrations, you’re setting your project and organization up for success.
Like Ben Franklin said, “By failing to plan, you are preparing to fail”.