In many cases the NSSS pressure signals are generated by the safety system instrumentation. Pressurizer pressure and main steam pressure are two types of signal that come to the NSSS control system through isolators from the safety system. Feedwater pressure, on the other hand, is an example of a non-safety signal that is dedicated to the NSSS function.

In the case of feedwater pressure and other NSSS dedicated sensed parameters, the iPWR designer has the flexibility to use newer designs and technologies as the evolution pedigree for safety system qualification is not required. But because some of the NSSS signals are located in accessible places with typically more space than the safety system devices, options to use the traditional sensors can be considered.

Many of the traditional suppliers of pressure sensors have modernized the signal processing (to digital in most cases) and are modifying their products with state-of — the-art processing methods. They are transitioning toward digital processing whenever possible. Also many I&C designers are using wireless set-up options whenever possible. (A discussion on wireless vs. wired solutions is in Section 6.8.3.) These advances within the traditional methods, give the traditional sensor manufacturers an advantage in the NSSS instrumentation market.

The new technology options for NSSS pressure sensors/transmitters are covered under Section 6.2.2.