From the September 2016 issue of HealthCare Business News magazine
The modular nature of shield block systems may qualify a structure to be eligible for accelerated depreciation because it can be dismantled and reassembled at another location. Each facility is unique and will require the appropriate review by a certified accountant, but if the system is determined to qualify, this may provide a significant financial benefit over a poured-in-place concrete system. Modular systems may have a slightly higher initial cost than poured concrete systems, but the multiple benefits achieved, such as recoverable materials, reduced installation time and reduced “time to first treatment” may offset and outweigh such costs.
Hybrid/specialty applications
Due to the versatility of concrete systems, especially in modular form, there are a number of hybrid or specialty concrete shielding applications available. Some facilities have decided to combine the space savings of heavy concrete with the cost savings of regular-density concrete. One example of this is the use of heavy concrete in the primary shielding areas (with the most intense radiation) while using regular-density concrete in the secondary shielding areas (lower radiation intensity) of a linear accelerator treatment room. By using heavy concrete to reduce the primary shielding thickness (from as much as 8 feet or more down to as little as 4 feet or less), the room can have consistent wall and ceiling thicknesses throughout.
The increase in concrete density in the primary locations has the benefit of reducing the footprint for the treatment room (area and volume) and relieves the architect or interior designer from having to figure out how to utilize the areas created on either side of the “bump-outs” created in a single-density concrete design. Another flexible use of concrete in treatment room design is the use of modular shield blocks to fill an opening in a treatment room wall after a machine has been installed. A facility may have limited space available to bring a treatment machine into a shielded room.
Whether the structure is built from poured-in-place concrete or modular blocks, the machine can be brought in through a hole in a wall that can be filled with modular shield blocks after installation. This modular shielded area can easily be removed and replaced any number of times to allow for servicing or replacement of a machine in the future.
Incorporating the extremely valuable benefits of high-density concrete and pre-cast modular shield block systems provides owners, architects and builders with multiple beneficial design solutions to consider. Whether shielding for a PET/CT, HDR/brachytherapy, linear accelerator or a higher energy particle therapy system, high-density concrete and modular shield block systems deserve due consideration.
About the authors: Jim Noller is vice president, sales and marketing at Shielding Construction Solutions, Inc. Daniel Harrell is vice president, operations at Shielding Construction Solutions, Inc. Manjit Chopra is the president of Nuclear Shielding Supplies & Service.Back to HCB News
