Please download a copy of The 52 Cetasikas at a Glance to understand what are all the cetasikas.
Vedana & Sanna together with Sankhara formed the 52 Cetasikas and thus Sankhara has 50 Cetasikas.
Read the following posts to have a better understanding about Pabhassara citta:
Pabhassara Citta, Radiant Mind, and Bhavanga
Citta, Manō, Viññāna – Stages of a Thought
Amazingly Fast Time Evolution of a Thought (Citta)
If you have understood what sankhara (san + kara = action done with san where san is the good and bad things we aquired) is, you will know that the pabhassara citta is not related to anicca or dukkha.
Only Arahant has pabhassara citta which means each thought (a citta) will only have the 3 stages from citta, mano and manasam only and no further than that of contamination.