The Spallation Neutron Source is currently upgrading its accelerator power level from 1.4 MW to 2.8MW via the Proton Power Upgrade Project. This power upgrade requires updates to the RF system, superconducting LINAC, accumulator ring, and conventional facilities. The PPU will deliver 2.0MW to the existing SNS target and 0.8MW will be delivered to the future Second Target Station to facilitate new types of experiments and discoveries. The new power level fully applied to the existing target would allow the beam to damage the target and potentially produce hazardous radiation levels. To mitigate this risk, personnel protective system (PPS) called the Beam Power Limiting System (BPLS) has been designed to calculate the average and per pulse power, and to shut down the machine in the event of an excursion. Traditionally, PPS systems are implemented in programmable logic controllers designed to industrial safety standards. In order to quickly acquire measured data and calculate integrated power in real-time, a field programmable gate array (FPGA) was chosen to do the processing. The FPGA is implemented via off-the-shelf MTCA chassis and expansion boards. While MTCA has been applied in industry to life safety critical systems, the Beam Power Limiting System presented unique challenges and benefits when applying accelerator PPS design methodologies to MTCA technology.