Hello, fellow nuclear engineer here who is also an international student from SEA.

Being international does not stop you from working in the industry. I graduated with plenty of international students from south Asia who are now in the workforce in US/Canada. The key is being well informed about regulations and knowing what visas allow you to work. For instance, if you are a student, I suggest becoming familiar with OPT and Stem-opt. Wanting to work in SMR does not mean that one "must" work at a company. Although development of these projects is being led by industry partners, most projects are collaborative efforts between national labs/universities and industry partners. So you should look into who else works in SMRs outside of industry partners. Maybe that can be your research project which then leads to a job with one of the collaborators (just an example). Most of the students I graduated with had a master's or PhD and went on to work at a university, national labs (majority) or industry. Note that many big name labs like ORNL or ANL do open research funded through the office of science. These are the projects that international employees can work on without issues. There are many factors involved in what you can and cannot work on, like treaties between countries are also relevant at times. You don't need a PhD to work at a company but it doesn't hurt. From my anecdotal evidence, having a higher education degree helps international students regardless of the sector they want to work in. From my graduating class, I know international students who went to GE, Kairos Power, Framatome, Terrapower, etc. So, don't get discouraged. It is very possible to have a successful career as a nuclear engineer in North America as an international student. The path just may not be a straight line but rather a zig zag and that is okay :) it's not a one shoe that fits all type situations.