Investigation into corrosion products formation in the main technological APS systems with RBMK-1000 during operation

Investigated is the corrosion state of structural material surfaces in the APS systems and equipment with the RBMK-1000 after 21.000 hours of operation. The corrosion product (c.p.) probes were selected from interior surfaces of the equipment on the various parts of the main APS contour. The corrosion deposits in the systems of perlite steels (st. 20, st. 3, st. 22K) wholly consists of iron oxides in the form of α-Fe2O3, Fe3O4, γ-F2O3 and γ-FeOOH. The continuous c.p. film of the following spinel composition (Fe, Ni)O-(Fe, Cr)2O3, is formed on the equipment made of the stainless steel of the Kh18N10T type. The friable c.p., taken from the bottom of the drum-separator, contains 45-50% of Fe, up to 2% Cu, up to 0.6% Ni and up to 0.5% Mn. The corrosion deposits possess the radioactivity which is mainly due to the containment of 51Cr, 54Mn, 60Co, 95Zr -95Nb, 144Ce, sup(10C)Ru. It has been established that most of the corrosion occurs in the steam pipes emerging from the dram-separator and also in the deaerator tank. But in a whole the quantity of corrosion deposits inside the main APS systems is small and working surfaces of this systems are in satisfactory state