Safety Integrity Level (SIL) Requirement for R&D Nuclear Reactor

I did some searching but could not find if there is a requirement for safety instrumented systems (SIS) to undergo a SIL analysis if it is a research and development (R&D) type application for nuclear reactors. Does anyone know if it is or not?
Information on any part of the Nuclear industry is by it's very nature secure; if you are working in it you would realise that.

In my day there was no SIS, just the equivalent under a different name.
Process Engineers would advise whether SIL analysis is required or not; however I would expect safety instrumented systems to be already analysed.
Been dealing with Nuclear Plant Protection for years. The reactor uses a 2oo4 relay system. Equipment outside the reactor such as turbine, generator, pumps, follow OSHA rules.
Regards, Phil Corso