Guide tube for an instrumentation lance extending into a pressure vessel, reactor pressure vessel, and a method for preventing the accumulation of particles outside the pressure vessel in a guide tube

摘要

The invention relates to a guide tube especially for an instrumentation lance extending into a reactor pressure vessel. The guide tube includes a lower tube section and an upper tube section that extends into the interior of the reactor pressure vessel. In order to prevent radioactively contaminated particles from reaching the lower tube section disposed outside the reactor pressure vessel from forming a source of radiation, a separator is arranged in the upper tube section. The separator has a separation chamber in which the particles are deposited and are removed from the water.