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; *; ; Miyaguchi, Kimihide
Nihon Genshiryoku Gakkai-Shi, 27(10), p.939 - 952, 1985/10
Times Cited Count：0 Percentile：0.02(Nuclear Science & Technology)None
Himeno, Yoshiaki; ; Kawada, Koji*; Kawabe, Ryuhei*; *; *; Miyaguchi, Kimihide
PNC TN941 85-130, 65 Pages, 1985/09
Test of sodium fires in an auxiliary building of the fast reactor has been conducted by use of a test rig in which reduced scale models of a sodium pipe, a floor liner, a sodium drain pipe, and a smothering tank were installed to simulate the configuration of fire mitigation systems in the reactor. In the test, a 150kg sodium at temperature of 505 
C was spilled from the model sodium pipe at flow rate of 1 
/sec for 3 minutes. Then a whole accident sequence that starts from a sodium spill and ends at a self-extiguishment of fire within the smothering tank was studied. From the test results obtained and through their analysis, the following conclusions were drawn. (1)A whole sodium leak and fires accident sequence proceeded as expected in the Monju design, i,e., a spilled sodium was smoothly drained into the smothering tank via the floor liner and the drain pipe, then sodium fire was self-extinguished in the smothering tank. (2)In regard to the model sodium pipe, failures of the thermal insulation jackets due to sodium corrosion and due to generated sodium combustion heat are not found. The thermal insulation jackets kept its original geometries and functioned propely as a barrier to prevent the dispersion of spilled sodium into the atmosphere during the test. No flow blockage of a spilled sodium occured both on the floor Liner and in the drain pipe. Combustion heat of mixed fires (a columnar fire and a pool fire) that occured within an accident cell of the test rig was determined to be 1.6 times of that of a pool fire. This value is not so large as expected and indicates that the mild fires proceeds during the test. (3)With the smothering tank, temperatures data of sodium, steel liner, perlite concrete, and structural concrete were obtained. The data of concretes indicated that the structural concrete was not heated so high as to interfere its structural integrity. A total water released from the concretes per unit surface area of the liner ...
Miyake, Osamu; Yamazaki, Hiroshi*; *; Himeno, Yoshiaki; Miyaguchi, Kimihide
PNC TN941 85-131, 53 Pages, 1985/08
For the analysis of sodium pool fire accidents in the LMFBR safety design, the computer codes SOFIRE-MII and ASSCOPS (the latter evaluate the pool-spray combined fires) have been utilized. In regard to the combustion phenomena of pool fire, better understanding has been obtained by experiments since the time of development of above mentioned codes. On the other hand, for the purpose of rationalization of the present LMFBR plants, the detailed analysis code is supposed to be required which can evaluate the sodium fires and their thermal effects more accurately and can remove existing conservatism of the present codes. Therefore, considering the requirement of the current status and trends, a new sodium pool fire model (SPM) has been accomplished mainly aiming at the evaluation of sodium fires under the air-filled secondary system condition. To model the actual phenomena precisely as possible, SPM takes account of the combustion flame above the pool surface, and the combustion heat and the heat transports to ambient and to the surrounding structures are estimated. To verify SPM, the comparisons of calculated results with experimental data obtained by the U.S. HEDL's CSTF and the German KfK's FAUNA facilities are presented. The comparisons with SOFIRE-II and SOFIRE-II are also discussed. Results show that the SPM predictions give reasonable agreement or somewhat overestimation, though, the pool temperature predictions are greatly improved in comparison with those of SOFIREs.
Kawabe, Ryuhei*; Himeno, Yoshiaki; Kawada, Koji*; Miyaguchi, Kimihide
PNC TN941 85-104, 17 Pages, 1985/06
Flow and combustion test of low temperature sodium (250C) on a simulated for liner has been conducted to give an answer to the possible flow blockage or flow plugging. The simulated floor liner used for this purpose was 2.4m in length and 1.2m in width having liner gradient of l/100. The bottom surface of the liner was well thermally insulated. In the test, 160kg of sodium was slowly spilled from a nozzle having a wide opening at flow rate of 1 /sec for 200 sec. The nozzle was attached to the side of the liner. Flow pattern and combustion characteristics of sodium have been monitored during the test, and temperatures of the flowing sodium and a liner steel have also been measured. In the post-test examinations, distribution of residual sodium and sodium oxide on the floor liner as well as that in a drain pipe was determined. The results thus obtained were summarized as follows. (1)At beginning of the test, although the spilled sodium froze for a certain period of time due to its heat transfer to the liner, it remelted by taking heat from a successive flowing sodium at higher temperature. Therefore, on the liner sodium flowed continuously without being blocked its flow path. (2)Heat flux from sodium to the liner was less than 80kw/m
, while related heat transfer coefficient was 300 
500w/mC. The latter value was almost the same to that obtained from the similar test with hot sodium (505C). (3)Post-test examination revealed that the distribution of residual sodium and sodium oxide on the floor liner was almost uniform with the average value of 1kg/m. No massive combustion products that may cause flow plugging was found in a sodium drain pipe.
Miyake, Osamu; Kawabe, Ryuhei; Himeno, Yoshiaki; Miyaguchi, Kimihide
PNC TN941 85-67, 43 Pages, 1985/03
The SOFIRE-MII code, which was developed based on the U.S. SOFIRE-II code, analyzes a sodium pool fire accident in the LMFBR plant to predict the pressure and temperature of atmosphere as well as the structural temperatures within a reactor building. To date, the code has been validated by test data at low oxygen concentrations. However, the code validation at high oxygen concentration has been incomplete. To complete this validation, the calculations of pool fire test results that were obtained with an air-filled closed vessel, are conducted. The test results used for this purpose are those taken from the FAUNA F5 and F6 tests. FAUNA is a large sodium fire test facility installed in Kernforschungszentrum Karlsruhe (KfK), Federal Republic of Germany. The calculations include sensitivity studies on the important input parameters in SOFIRE-MII; the burning ratio, S (weight ratio of sodium/oxygen consumed by a the radiation heat exchange coefficient, F between a pool and the atmospheric gas, and the heat removal rate from the external surface of the test vessel. Enhancement of sodium combustion at the initial stage of the test due to sodium filling by a columnar high-speed sodium flow from an open nozzle over the pan is also evaluated. The result indicates that, as a whole, the test results are predicted fairly well by SOFIRE-MII with the S value of l.44that represents the sodium combustion generating 100% sodium peroxide as its reaction products and with F=0.65. The sensitivity studies of these parameters indicate that the S value has a significant effect, while the F value does not. The heat removal rate from the external surface of the vessel has also a little effect on the gas pressure and temperature, although the vessel wall temperature is significantly affected by this. Contribution of a columnar combustion during the sodium fill at, the initial stage of the test is found to be significant to the initial gas temperature and pressure spikes.
*; Yamazaki, Hiroshi*; Miyake, Osamu; Kawabe, Ryuhei*; Himeno, Yoshiaki; Miyaguchi, Kimihide
PNC TN952 84-13, 159 Pages, 1984/11
In an LMFBR, the consequences of a sodium spill in the heat transport system need to be determined. Analyses of sodium fires in such accidents have been performed in use of various computer codes. At PNC, two computer codes, SPRAY-III M and SOFIRE-M II, had been utilized separately for the spray fire and for the pool fire, respectively. To provide the combined spray-pool fire calculation, ASSCOPS (Analysis of Simultaneous Sodium COmbustions in Pool and Spray), which is described in this report, has been developed as an integrated code of those codes for the computation of the pressure and temperature. This report consists of descriptions of the input and output formats and the job control procedures of ASSCOPS.
*; *; *; *; Miyaguchi, Kimihide; *
PNC TN941 84-121, 56 Pages, 1984/08
At the Delayed Monitoring system, which in one of the Fuel Failure Detection System in JOYO, some probrems had occurred since the 6th cycle of 75MW power operation at MK-I core. As a result of inspection from Feb. 1983 to Mar. 1984, it was found that the various electrical noises interface with it's normal function. So many kinds of noise appeared at power supply circuit, pre-amplifier circuit and cable lines. Though this Phenomenon was a difficult problem to deal with, We could remove injurious electrical noises successfully. lt's working effects were indicated as follows, (1)At first an AC Line Conditioner was built in power supply circuit. (2)An adjustment was made on the pre-amplifier circuit and some circuit parts were replaced in order to alter the circuit. (3)Most of signal line at BF-3 monitoring system was changed from coaxial cable to glass fiber cable partially.
*; Maeda, Yukimoto*; Miyaguchi, Kimihide; *
PNC TN941 84-100, 51 Pages, 1984/06
In the 4th annual inspection of "JOYO", the remote visial inspection of the primary main pump (A) outer-casing was carried out as one of inservice-inspection in order to confirm the integrity of the welds and examine the condition of sodium deposition after being drained. The inspection was conducted when the primary main pump (A) was over-houled and by using Multi-Purpose Inspection Industrial Television (MPI-ITV) the condition of the outer casing inner surface was displayed clearly on TV and recorded by the video tape recorder. By the inspection, no degradation of the welds was found and the condition of the sodium drain was confirmed to be well. These results showed that this inspection method was effective as one of inservice-inspection in case that the access to the equipment was difficult.
; *; ; Miyaguchi, Kimihide; Endo, Junichi
PNC TN941 83-124, 172 Pages, 1983/08
In the Experimental Fast Reactor "JOYO", In-Service Inspection (ISI) of the primary main cooling piping was conducted during the annual inspection and maintenance period. Inspection of the main piping was performed only at four elbow locations. (two in each loop). Access to the main pipe wall surface is through inspection port holes in the outer piping. Examination of the piping for possible surface degradation, cracks, or wall thickness changes is made using direct visual inspection, remote visual inspection, dye penetrant inspection, surface replicas, and ultrasonic inspection. Inspection records were made, compared with Pre-Service Inspection (PSI) results, and stored for future reference. The examination has been performed three times including one PSI and ISI with no indication of degradation of piping integrity.
*; *; Miyaguchi, Kimihide; *
PNC TN941 83-71, 110 Pages, 1983/06
As a series of the 3rd annual inspection of Joyo, the 3rd integrated leak rate test (ILRT) of the pressure containment vessel was conducted to confirm the leak tightness of the containment vessel and to determine the test frequency and method in future. Results obtained from the test are summarized as follows; (1)Leak rates of 0.013
0.010 %/day by the absolute pressure method and of 0.0440.014 %/day by the reference chamber method were obtained. After combining the results from local leak tests and correcting for measuring errors, the compensated leak rates were well within the leak rate limit of 1.90 %/day. (2)Since the test results obtained in the tests of past three times including this time were well reproducible and showed no signs of the degradation of the containment vessel, it is concluded that the ILRT of Joyo pressure containment vessel in future should be conducted by the frequency of three times in ten years. (3)The absolute pressure method should be adopted in Joyo as the test method in future, because the measuring accuracy by both the test method was confirmed to be almost equal, and the arrangement of measuring system for the reference chamber method is more complex than the absolute pressure method.
*; Setoguchi, Keiichi; *; *; *; *; Miyaguchi, Kimihide
PNC TN941 82-270, 109 Pages, 1982/12
Following surveillance tests ought to be performed five times during twenty years operation of Joyo. (1)Surveillance test of reactor vessel (2)Surveillance test of safety vessel (3)Surveillance test of primary main cooling system (4)Surveillanee test of secondary cooling system The first taking-out of surveillance test pieces from the secondary dump tank was carried out from Feb. 22 to Mar. 10, 1982, based on the surveillance test, program of secondary cooling system. We had to perform the work under the conditions such as the sodium filled in the dump tank and to protect the air from coming into the tank. This report describes the details of the working processes.
Miyaguchi, Kimihide*; Sato, Kazujiro; Iguchi, Tatsuro*
PNC TG033 82-01(5), 16 Pages, 1982/01
Several series of thermal and hydraulic experiments have been conducted using full mock-ups of JOYO fuel subassemblies. This paper describes the test results of cross-flow mixing and pressure loss in wire-wrapped pin bundles. It also presents the comparison between cross-flow mixing experiments and calculations by SWIRL code.
