High CPU usage Matlab 2017b

I use Matlab 2017b (university key) to creating a code integrating with a numerical simulation tool (EPA-SWMM).

My code generally takes around 10 hours to finish for 1 scenario but sometimes it collapses and the CPU usage of Matlab is approx. 100% and I cannot close Matlab properly. In some cases, Matlab and even computer are suddenly turnoffs.

My PC has enough free space in drives and Intel® Core™ i5-4670 CPU @ 3.4GHz RAM 8.0GB, NVIDIA GeForce GTX 650 Ti BOOST graphic card. I use Windows 10 and it is up to date.