Dismontle and cleaning of 1MW steam generator

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PNC TN941 74-24, 71 Pages, 1974/05

PNC-TN941-74-24.pdf:5.37MB

After 3,600 hours operation, 1 MW Steam Generator was Stopped and conveyed in parts and sodium in SG was cleaned successfully. This was the first experience in Japan and a lot of useful informations were obtained as follows about the dismontle of large scale sodium component. (1)By circulation of high temperature sodium (400, 450C) before drainage, the sodium was drained from SG almost perfectly. (2)In sodium pipeing near SG, there remained a little sodium. (3)Tube bunddle was pull out smoothly from SG without any troubles. (4)There was a lot of condensed sodium in cover-gas region. (5)The top of sodium level ditector and sodium distributor, and the bottom of downcomers dummy tube were bended and distorted. (6)There was a lot of black powder on the sureface of tube, liner and inner shroud.