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; ; Yamada, Takeshi; ; ; ; Kaito, Yasuaki; ; Kotaka, Yoshinori; ; et al.
PNC TN2410 96-005, 339 Pages, 1996/03
Construction of the 'Monju' fuel handling systems was completed in April, 1992. From March 1991 to August 1992, pre-commissioning tests were carried out. In December 1992, all the systems of Monju were transfered to PNC, and commissioning tests and reactor physics tests, were started. For the first time, during these physics tests, the fuel handling systems were operated for one of the commissioning tests 'Loading to Criticality', without significant problems. 168 fuel sub-assemblies were loaded into the core and the first criticality was achieved on 5th April 1994. The fuel handling systems continued in operation for the 'Loading to Full Size of the Core', power distribution test and for cleaning discharged dummy sub-assemblies. To keep these fuel handling systems working somothly and satisfactorily annual maintenance has been carried out since 1992. This paper describes the operation and maintenance experience of fuel handling systems after the pre-commissioning tests and future study items for system reliability improvement.
Kotaka, Yoshinori; Michino, Masanobu; *; *; *; *; Terunuma, Seiichi*
PNC TN9410 89-129, 50 Pages, 1989/04
In order to reflect JOYO operational and maintainable experience to MONJU, JOYO operation section has to interchange technical information with MONJU. This report is used technical information interchanging meeting with MONJU regarding to primary sodium purification system and described that experiences of sodium reception, sodium initial purification and sodium purification during power increase.
*; Kotaka, Yoshinori; ; *; ; *; *
PNC TN9410 89-038, 75 Pages, 1989/03
JOYO has been operated smoothly since the initial criticality in 1977. This report describes the actual operation experience of JOYO electric power supply system till Dec. 1988. Major results obtained from operation experience are as follows. (1)Accumulated electric power: 371,290,600 kWh (Oct. 1973-Dec. 1988) (2)The average electric power consumption of several reactor conditions. (a)Operation : about 4,460kW (b)Shut Down : about 3,350kW (c)Periodic Inspection : about 3,000kW (3)Number of loss of external electric power : total 10 times in the following items. (a)Operation : 8 times (b)Shut Down and Periodic Inspection : 2 times
Kotaka, Yoshinori; *; *; *; *; *; *
PNC TN9410 88-108, 121 Pages, 1988/03
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 150
C 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 ...
*; *; *; Kotaka, Yoshinori; *; *; *
PNC TN9410 88-045, 96 Pages, 1988/03
The Plugging Meter is used in JOYO Secondary Auxiliary Cooling System to monitor the sodium purity. This Plugging Meter have been operated more than 12 years since the coolant sodium was charged into JOYO Secondary Auxiliary Cooling System in 1975. Since its operation, some trouble conditions were observed and countermeasures have been taken. For these presume, the state of occurrence trouble conditions were investigated from 100MW 1st cycle operation to 100MW 14th cycle operation. The cause of some trouble conditions are as follows. (1)Increase of Plugging temperature during Reactor operation is supposed to be caused by unknown impurity precipitations except oxygen or hydrogen one. The unknown impurity is transfered from piping and component material in Secondary Auxiliary Cooling System after Reactor Power-up. (2)Sodium flow changes in Plugging Meter, like electric nois, are caused by gas into system sodium flow. (3)Sodium flow changes in Plugging Meter, in case that is not concerned with impurity precipitation, are caused by output voltage changes of the electromagnetic flow meter. This output voltage is shifted by sodium temperature changes. The researches and investigations of Plugging Meter in this system are continued to clear above and other specified matters, and take basically countermeasures.
