Position Design for Instrumentation Penetration of Reactor Vessel Based on None-Alignment Analysis

The position of the instrumentation penetrations of the reactor pressure vessel is the most important factor that influences the none-alignment between instrumentation penetrations and instrumentation tube of reactor internals. The more the none-alignment, the more wear the flux thimble will suffer, which will damage the flux detector and cause economic losses. This paper analyses the none-alignment between instrumentation penetrations and instrumentation tube, and combines the feedback of the experience in nuclear power plants having been built or being build, puts forward the reasonable design value for the instrumentation penetrations’ position.