device for irradiation and measurement in a fast neutron nuclear reactor

摘要

1387691 Reactors COMMISSARIAT A L'ENERGIE ATOMIQUE 22 Feb 1972 [23 Feb 1971] 8121/72 Heading G6C A monitoring system for use in a fast, liquidmetal cooled reactor comprises two concentric sleeves 6, 7 which extend into the reactor through a rotatable plug 4 within the biological shield, the outer sleeve 7 having its lower end placed only a small distance above the heads of the fuel assemblies 8, 9 and the inner sleeve 6 being displaceable from a retracted position (as shown in Fig. 1), above the core and an extended position (Figs. 2, 3, not shown), in which its lower end is disposed in a free space 11 within a fuel assembly 9. The lower end of the inner sleeve 6 comprises a glove finger 6aSP1/SP. The sleeve 6 is secured to an upper duct 6a by means of a socket 20. Near its top end, the sleeve 6 carries a packing 21 adapted to slide upon the chromium-plated inner surface of the outer sleeve 7. Within the rotatable plug 4, the outer sleeve 7 has a thickened portion 7a which completes the biological shielding of the reactor provided by the biological shield and the rotatable plug 4. When the glove finger 6aSP1/SP is inserted into the reactor core, a measuring probe (34) (Fig. 3, not shown), for measuring the neutron flux can be introduced via the inner sleeve 6 into the glove finger 6aSP1/SP. A hoisting gear 28 for handling the sleeves 6, 7 as well as the probe (34) is mounted on an anti-explosion platform 27 erected around the top of the core cover 5. A collapsible hood 29 surrounding the duct 6a is fitted to a flange 7b at the top of the outer sleeve 7. An inert gas (e.g. argon), is passed into the hood 29 and thence into the outer sleeve 7 via a supply pipe 30.