Analysis of operation records; Evaluation of event sequences in extruder

; Miura, Akihiko; ; Sano, Yuichi

JNC TN8410 99-043, 135 Pages, 1999/10

JNC-TN8410-99-043.pdf:6.44MB

All result of chemical analysis and operators observation suggest non-chemical mechanism raised the filling temperature of the bituminized product at the incident. We, Tokai reprocessing plant safety evaluation and analysis team, performed the experiment using laboratory scale extruder and viscosity measurement to explain the high temperature of mixture. The result of the experiment using laboratory scale extruder showed that the phenomena of salt enrichment and salt accumulation oceured and they raised mixture temperature at the decreased feeed rate. These phenomena depend on the feed rate and they have large contribution of heat transportation and rise of operational torque due to the friction between screw and mixture. Based on the experiment result and all information, we investigated the operation procedure, operational records and machine arrangement to try to explain the behavior of the mixture in the extruder. Judging from each torque and temperature behavior, we succeeded in explaining a sequential behavior in the incident. It is estimated that mixture temperature was raised by physical heat generation in the extruder and this report explains each operation, investigated result and estimated event sequences.

Development of the flow control irradiation facility for JOYO

Soroi, Masatoshi; Miyakawa, Shunichi

PNC TN9410 98-050, 57 Pages, 1998/05

PNC-TN9410-98-050.pdf:1.58MB

This report describes the present situation and problems with the development of the flow control irradiation facility (FLORA). The purpose of FLORA is to run the cladding breach (RTCB) irradiation test under loss of flow conditions in the experimental fast reactor "JOYO". FLORA is a facility like FPTF (Fuel Performance Test Facility) plus BFTF (Breached Fuel Test Facility) in EBR-II, USA. The technical feature of FLORA is its annular linear induction pump (A-LIP), which was developed in response to a need identified through the experiences in the mechanical flow control of FPTF. We have already designed the basic system facility of FLORA for the JOYO MK-II core. However, to put FLORA to practical use in the future, we have to confirm the stability of the JOYO MK-III core condition, solve problems and improve the design. The main results and problems of the development of FLORA are as follows; (1)The results of the development: (a)The neutron detector in FLORA can detect the delayed neutron which is emitted from failed fuel. (b)Out-of-pile A-LIP tests in sodium conditions has been completed. (The length of the tested A-LIP is half the actual size.) Out-of-pile test results showed that the A-LIP achieved a 300/min flow rate and 265kPa pressure in 550C sodium. This pump performance satisfied the FLORA requirements. (c)By controlling the sodium flow rate from 40 to 100% using the A-LIP, we can control the fuel cladding temperature satisfactorily. (2)The problems: (a)In the development of the process detector, it is necessary to miniaturize the neutron detector and test the effect of neutron irradiation and high temperatures on the permanent magnet in the flow meter. (b)The problem which is left about A-LIP is its influence on neutron irradiation. For this purpose, we have to irradiate a small size A-LIP and test its characteristics and electric isolation. (c)To get more accurate results concerning the efficiency of the A-LIP, we have to ...

None

PNC TJ1612 97-001, 69 Pages, 1997/03

PNC-TJ1612-97-001.pdf:2.25MB

no abstracts in English