JOPSS - Search Results

In order to establish the cross correlation method as the in-situ calibration of the electromagnetic flowmeter, sodium flow rate measurement using the 6 inches permanent magnet type electromagnetic flowmeter was conducted. And it was found that the calibration was possible within the accuracy of 4%. And useful method about the electrode positioning, signal processing and flow pattern correction were obtained for this purpose. This method will be applicable as the in-situ calibration method of "MONJU" main pipe flowmeter by the confirmation of this method on the larger pipe than this 6 inches' pipe.

Journal Articles

Eddy-Cerrent Type Void Detector for LMFBR Core Monitoring

; ; Tamura, Seiji; *

Proceedings of 3rd International Conference on Liquid Metal Engineering and Technology in Emergy Production, 0 Pages, 1984/00

None

JAEA Reports

Thermocouple response test (2); Measurement and evaluation of JOYO and MONJU subassembly outlet thermometer (Well type thermocouple)

*; *; *; *

PNC TN941 82-168, 64 Pages, 1982/09

PNC-TN941-82-168.pdf:1.89MB

It is very important to confirm time response of LMFBR subassembly outlet thermometers for core monitoring, plant control and estimation of thermal transient in various kinds of reactor components. The thermowell is used for subassembly outlet thermometers of JOYO or MONJU in order to protect a sheathed thermocouple from sodium and to keep the primary pressure boundary. This thermocouple assembly is called as well type thermocouple, and its response characteristics is considered to be influenced by shape and size of the well, materials (argon gas) filled into the gap between well and sheathed thermocouple, gap size, etc. Therefore, it is necessary to estimate its response characteristics under almost the same conditions as a reactor. The well type thermocouples (JSA and MSA), which simulated JOYO and MONJU subassembly outlet thermometers, were tested in sodium by step response method, and their time constants (1st and 2nd order time constants) were measured. The program SOFT was made for on-line data acquisition by a mini-computer and the time constants were calculated from measured transient signals. In order to generalize experimental results, the thermal transient analysis code for thermocouple, REST (one-dimension cylindrical model), was developed. From parameter survey by using REST, factors which significantly influence the time constant were investigated. Optimization of the well type thermocouple in response was also discussed in this report.

JAEA Reports

Performance test of a probe-type eddy-current flow and temperature sensor (II); In-sodium tests of MK-II sensor

*; *; *; *; Atsumo, Hideo

PNC TN941 77-51, 190 Pages, 1977/01

PNC-TN941-77-51.pdf:5.56MB

Probe-type eddy-current flow and temperature sensors have been developed for in-core monitors of prototype fast breeder reactor "MONJU". The MK-II sensor (11.0mm O.D. 130mm long, magnetic core) has a central primary coil and two identical coils placed symmetrically about the primary, and is installed in a stainless-steel guide tube. It is capable of monitoring sodium flow and temperature at a time by means of vector differencing and vector summing of secondary coil signals respectively. In-sodium tests were carried out under conditions in the Sodium Instrument Test Loop. [Sodium temperature : 300 550 $^{circ}$ C] [Sodium flow velocity : O 3 m/s] [Exciting frequency : 20 1000 Hz] Test results are as follows. (1)The performane as a flow sensor : The output/flow characteristic was linear up to 3 m/s, and has high sensitivity as much as 1.34 mV/m/s at 75 Hz. The temperature dependency of flow output signal were reduced to 1% (400 500 $^{circ}$ C) with a temperature compensation circuit. (2)The performance as a temperature sensor : Temperature detecting sensitivity was 48.5V/ $^{circ}$ C at 75 Hz, and linearity was fairly well in the Temperature range, 300 500 $^{circ}$ C. (3)It was shown that both flow and temperature outputs are useful for detecting gas bubbles in sodium. (4)It became clear that the top shape of a guide tube has not an important effect on the flow output signal, after testing conic, spherical, ellipsoidal, cylindrical guide tubes and spherical one with fins. Some basic problems, such as the potential of detecting subassembly flow blockage and/or gas bubbles in sodium, were discussed in order to apply this sensor to in-core instrumentation of LMGBR.

JAEA Reports

Transit time flowmeter using flow-induced noise in Sodium(I); Preliminary test for 3B PM flowmeter

*; *; *; Nakasuji, Takashi

PNC TN941 77-186, 36 Pages, 1977/01

PNC-TN941-77-186.pdf:1.02MB

A preliminary test was carried out in sodium, to confirm the principle of a transit time flowmeter employing cross-correlation technique of flow-induced noise. The tested permanent magnetic flowmeter (81.1mm I.D) has five pairs of electrodes arranged at equal distances along the flow direction. The transit time between electrodes was measured under conditions, and was transformed into a transit velocity using distance between electrodes (L)/transit time ( $^{*}$ ): [Sodium temperature : 500 $^{circ}$ C] [Average flow velocity : 04 m/s] [Distance between electrodes : 4, 8, 12 ㎝] Conclusions are as follows : (1)The characteristic of transit velocity vs reference velocity was livear up to 4m/s except L=4㎝. (2)In case of L=12㎝, the obtained transit velocity agreed with a reference velocity within the accuracy of a reference flowmeter, but there was disagreements in both velocities in other cases. (3)It was clarified that power spectrum of fluctuation signal of PM flowmeter has relatively low frequency range ( 10Hz), and that the break frequency and spectral density become higher and greater respectively as increase of flow velocity. (4)The non-linearity of transit velocity when L=4cm and 3m/s, should be further investigated from both viewpoints of flow characteristics itself and instrumentation technique.