Part-Time Employee?

I have 16 years federal service as a Hybrid 38 in a GS-12 position. 9 of those years were full time and the last 7 have been part time (.5 FTE). Several coworkers and some of what I've read seem to say I have no RIF protections and would likely be the first to go compared to full time employees in the same job series. Can anyone provide any specifics or direction for the RIF could mean for me as a part-timer?