Experimental fast reactor JOYO operational experience; The operational experiences of JOYO secondary sodium purification System

Kotaka, Yoshinori; not registered; not registered; not registered; not registered; not registered; not registered

This paper describes operational experiences of Joyo Secondary Sodium Purification System which were obtained from September 1979 in the middle of the first annual inspection and maintenance to March 1987 in the middle of the 6th annual inspection and maintenance. The test results were as follows. (1)The impurities in the secondary sodium cooling system were oxygen and Hydrogen. The impurity density corresponded to the plugging-temperature. (2)The cold trap control temperature was changed from 150C to 130C on 16 May, 1982 in order to decrease corrosion due to the impurities in the secondary sodium cooling system. (3)The purification efficiency test of secondary cold trap was conducted on 26 through 29, December 1979. It was found that purification efficiency coefficient was 80%. While the test conducted, secondary cooling system was held at 200C constant. (4)Sodium charge in the secondary sodium purification system was conducted on 25 October 1980 and the secondary cold trap was started to be in use. In the secondary cold trap it was happened to be abnormal tendency, that is, the cold trap control temperature could not be abated to the set temperature, the heat exchange of economizer was not enough, and the mesh temperature changed. As a result of examination, the cause of the abnormal tendency was presumed that argon (Ar) gas space happened to exsist in sodium of secondary cold trap. The argon (Ar) gas space was supposed to be provided during the sodium drain in the secondary sodium purification system. Some recovery plant operation was proceeded ln order to reduce the argon (Ar) gas space out of the secondary cold trap. Thereafter, the secondary cold trap was operated without any trouble. (5)The number of cases of the secondary purification system trouble was 28. Among them, electrical troubles happened twelve times, mechanically oriented troubles happened sixteen times. Those troubles, however, did not affect to the ...