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-semiquinone complex; A Possible dielectric response mechanismMitsumi, Minoru*; Ezaki, Kazunari*; Komatsu, Yuki*; Toriumi, Koshiro*; Miyato, Tatsuya*; Mizuno, Motohiro*; Azuma, Nobuaki*; Miyazaki, Yuji*; Nakano, Motohiro*; Kitagawa, Yasutaka*; et al.
Chemistry; A European Journal, 21(27), p.9682 - 9696, 2015/06
Times Cited Count：7 Percentile：25.07(Chemistry, Multidisciplinary)
CHasegawa, Naruo; *; Kano, Shigeki; Nakayama, Koichi; Nakasuji, Takashi; Koakutsu, Toru
PNC TN941 80-127, 124 Pages, 1980/08
It is an important subject to clarify the tribological behaviors of structural materials applied for contacting and/or sliding parts of "MONJU" components and take a measure to meet the design condition. From this point of view, a series of parameter tests are conducted on stellite No.6, Colmonoy No.5, Inconel 718 and LC-1C selected by the screening tests, and SUS 316, SUS 304 and 2.25Cr-1Mo steel as main structural materials for "MONJU". Among parameters, the effect of oxygen content in sodium on tribological behaviors is one of disputed points. As the cold trap temperature of "MONJU" primary system is intended to decrease from 140C (or 145C) to 120C, the authors started the tests whose parameter is cold trap temperature. This report describes the test results obtained partially. The test items and test conditions are as follows: I. Corrosion Test Sodium temperature : 600C, Exposure time : 2,000 hr. Cold trap temperature : 120C II. Friction Test Sodium temperature : 600C, Exposure time : 2,000 hr., Contact stress : 0.3kg/mm
. Cold trap temperature : 120C III. Self-Welding Test Sodium temperature : 450 
700C, Dwell time : 200 hr., Contact stress : 4 kg/mm , cold trap temperature : 120 C Comparison of as-received material with pre-exposed material. Estimation of self-weldability by tension breakaway. Main results obtained are as follows: I. Corrosion Test (1)Corrosion behavior did not indicate apparent difference between cold trap temperature of 120C and 140C. (2)Stellite No.6 showed an increase in weight and other materials tested showed a reduction in weight. II. Friction Test (Stellite No.6/itself and LC-1C/itself) (1)Kinetic friction coefficients did not show apparent difference between cold trap temperature of 120C and 140C. (2)Kinetic friction coefficients did not depend on sodium exposure time. III. ...
*; Kano, Shigeki; Nakasuji, Takashi
PNC TN941 80-55, 126 Pages, 1980/04
As the basis for designing and manufacturing the fuel assembly for MONJU, and for confirming its integrity, it has been required to get the data concerning tensile properties of various heats of fuel cladding tubes exposed to different sodium environments. In this report, thirteen heats of fuel cladding tubes containing four kinds of ones manufactured in a few foreign countries were examined. These tubes were exposed to sodium at the linear temperature gradient test section of the Material Test Sodium Loop 1 for about 5000 hours. After that, tension tests of these tubes were made to clarity effects of sudium exposure on these tensile properties. Furthermore, additional tests related to these tensile properties were done. The results obtained are as follows. (1)From comparison of tensile properties before and after sodium exposure of these tubes, yield strength and tensile strength decreased after exposure, and fracture elongation increased. The variation amount of the values on tensile properties depended on exposure temperatures, and it was largest in the case of 500C. (2)The effects of cold-working and grain size on tensile test temperature dependence of tensile properties after exposure to flowing sodium up to 650C were similar to those before exposure in tendency. In respect to the effect of chemical composition, it is considered that minor boron content contributes to enhance the stability of tensile properties for sodium exposure. (3)From comparison of the tensile strength values (yield strength Sy, tensile strength Su) applied for designing the Monju fuel assembly with the present test results after sodium exposure, the experimental values were higher than those uf Sy and Su of annealed SUS316, but lower than those of Sy and Su of 20% cold-worked SUS316. (4)After tension test of sodium exposed tubes within the temperatures of 500C to 650C, many grain boundary cracks in slight depth were round out in the sodium ...
Kano, Shigeki; Hasegawa, Naruo; Nakayama, Koichi; Koakutsu, Toru; *; Nakasuji, Takashi
PNC TN941 79-144, 47 Pages, 1979/08
It is requested to obtain the self-welding characteristics in sodium on the contacting materials of "MONJU" components. By tension breakaway method, the tests were up to date conducted on many kinds of materials in sodium which was not cold-trapped
and was purified by the cold trap temperature of 190C
or 145C
. These results were used for material screening. The present study relates to the dwell temperature dependence of 200 hrs. self-welding characteristics on the selected hard facing materials and main structural materials of "MONJU" in 450 700C sodium purified by the cold trap temperature of 140C or 145C. The main results obtained are as follows. (1)The breakaway stress shows the apparent dwell temperature dependence. (2)The combinations of SUS 304/itself and SUS 316/itself self-weld above 500C and the breakaway stress increases linearly with the dwell temperature. (3)Ferritic steels exhibit the higher breakaway stress than austenitic stainless steels. (4)The combination of LC-1C/itself does not easily self-weld even at 700C. The combinations of Stellite No.6/itself, Colmonoy No.5/itself and Inconel 718/itself self-weld at 700C and do not self-weld at 600C. Only Colmonov No.5 breakaways at the inside as well as the self-welded interface. (5)Only Colmonoy No.5 shows the apparent corroded surface among the test materials after exposure to 700C sodium for 200 hrs. LC-1C exhibits flaking partially from the substratum. It is because the coating layer (0.2 mm thick) was too thick and there were the problems of the grid blast method on substratum surface and the manufacturing method on coating edge.
Koakutsu, Toru; Kano, Shigeki; Hasegawa, Naruo; *; Nakayama, Koichi; Nakasuji, Takashi
PNC TN941 79-105, 39 Pages, 1979/07
In view of anti-self-welding and low friction, hard facing materials are applied to the sliding parts of "MONJU" components. But it is thought that the self-welding and friction behavior of these materials is affected by sodium corrosion during long-term application at high temperature. At present report, a friction test was conducted in sodium to investigate the effect of the exposure time in flowing sodium on friction coefficient. This report describes the friction test results for Stellite No.6, Colmonoy No.5, Inconel 718, LC-1C (chromium carbide/nichrome binder) and SUS 316 under the following test conditions : the test temperature of 600C, the cold trap temperature of 140C, the test duration of 2000 hrs., the sodium velocity of 0.7 m/sec, the contact stress of 0.3 Kg/mm, the sliding stroke of 
5 mm and the sliding velocity of O 0.63 mm/sec, The results obtained are as follows. (1)All of test materials except for Colmonoy No.5 did not show the exposure time dependency of kinetic friction coefficient (
), (2)Degraded layer was appatently observed on the surface of Colmonoy No.5. (3)The coating method must be improved for LC-1C, because the LC-1C of 0.2 mm thick showed edge chipping. (4)The values were as follows. [Stellite No.6/self : 0.15 0.35] [Colmonoy No.5/self : 0.15 1.5] [Inconel 718/self : 0.65 1.15] [LC-1C/self : 0.35 0.55] [SUS 316/self : 1.0 1.2]
Hasegawa, Naruo; Kano, Shigeki; Nakayama, Koichi; Koakutsu, Toru; *; Nakasuji, Takashi
PNC TN941 79-26, 44 Pages, 1979/04
Friction, wear and self-welding resistant materials are applied for many contact and/or sliding parts in FBR components. The pad material of a fuel assembly wrapper tube is a ypical example. Wrapper tube pads of "MONJU" size were trially manufactured with four kinds of hard facing material selected by up to date R&D tests ((1)Stellite No.6 (2)Colmonoy No.6, (3)LC-1C (Chromium Carbide), (4)Inconel 718). In this study, these pads were exposed to 600C sodium for 2,000 hrs.. The following results were obtained. (1)The dimension between the inside of wrapper tube and the pad surface partially changed max. 200m due to the heating during sodium exposure. (2)Stellite No.6: After exposure, the surface showed general corrosion and selective corrosion at the grain boundary. The hardness slightly decreased to Hv 600 and surface roughness slightly increased. (3)Colmonoy No.6: After exposure, the surface showed severe general corrosion, then the depletion of boron and silicon and the degraded layer were observed in the vicinity of the exposed surface. The hardness of this layer significantly decreased to Hv 300 and the surface roughness slightly in creased. (4)LC-1C: After exposure, the surface showed slight general corrosion but cross-sectional micrograph was stable. The hardness increased to Hv 1,100 and the surface roughness slightly increased. (5)Inconel 718 : After exposure, the surface corrosion was slight, but titanium, niobium and molybdenum were depleted in the vicinity of the expoded surface. The hardness and surface roughness did not change before and after exposure.
*; *; Nakasuji, Takashi
PNC TN941 78-94, 40 Pages, 1978/01
Radioactive sodium removal is required to primary system components of sodium cooled fast reactor for inspection, repair or maintenance. A steam and an alcohol process are generally used to removal of this sodium from the components. In order to evaluate safety of the facility in which radioactive sodium is removed from the components by using alcohol, it was required to determine transfer rates of radioactive Iodine into gas phase and liquid phase, when the sodium was dissolved with alcohol. Based upon above requirement, a study was conducted. This report has been described experimental procedure and measuring results of Iodine transfer rates. Measurement of the transfer rates have been done by counting iodine activity distributed between the gas phase and the liquid alcohol phases, after dissolving sodium into the alcohol containing radio Iodine, scince preparation of sodium contained radio Iodine in phomogeneous is difficult. Transfer rate of Iodine-131 into the gas phase was below 10
, when bubbling gas was introduced into alcohol in a reaction vessel. Transfer rate, however, into the gas phase indicated 10
level when cover gas flowing was introduced into a upper space in the reaction vessel with conbination of the bubbling gas flow. Transfer rate of Iodine-131 into the liquid phase was 1.0. So it was found that Iodine-131 is near completely retained in the liquid phase under this experimental conditions.
Hasegawa, Naruo; Kano, Shigeki; Nakayama, Koichi; Koakutsu, Toru; *; Nakasuji, Takashi
PNC TN941 78-100, 48 Pages, 1978/01
A series of experiments in sodium and argon environments have been carried out to develop and screen the friction and wear resistant materials used for sliding components of the sodium cooled reactor. As results of these test, we selected out several materials for candidated alloys. The present study was carried out about combination of Stellite No.6/Self, Colmonoy No.5/Self, Inconel 718/Self and Stellite No.6/SUS304 and long term sliding test (150 hrs.). The results obtained were compared with those of short term sliding test (15 min.) of preceding studies. The results obtained are as follows, (1)Kinetic friction coefficients () of Stellite No.6/Self and Colmonoy No.5/Self were in approximate agreement with short term test of proceding studies (: 0.20.4) (2) of Inconel 718/self showed a stable behavior with the sliding time although it raised at the begining of the test. (3) of Stellite No.6/SUS 304 indicated a variable behavior at the begining of the test, but after 40 hours sliding, it showed a stable behavior with the lapse of time and was about 0.60.7. (4)The Wear depth of Stellite No.6/Self and Colmonoy No.5/Self did not shift for the sliding time. (5)wear depth of Inconel 718 was 2 to 3 times greater than that of Stellite No.6 and Colmonoy No.5. (6)Stellite No.6/SUS304 combination showed the greatest wear depth of all material combinations tested.
Hirano, Masaatsu; Kohashi, Kazuyuki*; Yuhara, Shinichi*; Nakasuji, Takashi; Atsumo, Hideo
PNC TN951 77-03, 35 Pages, 1977/08
Strain controlled fatigue tests with triangular waveform in sodium and in air at 550
were conducted by use of the fatigue test facilities in sodium for the purpose of establishing the fatigue testing technique and clarifying the fatigue behavior in sodium. The results obtained are summarized as follows. The fatigue test technique in high temperature sodium involving the calibration method of the elongation of a specimen and push-pull rod was established. The fatigue life of SUS304 stainless steel in sodium at 550 was longer than that in air at the same temperature, at the same strain rate of 1
10
sec
and that of ASME fatigue design curve. Particularly, this tendency was larger as the strain range become lower.
Kano, Shigeki; Koakutsu, Toru; Hasegawa, Naruo; Nakayama, Koichi; Nakasuji, Takashi; Atsumo, Hideo
PNC TN941 77-111, 95 Pages, 1977/06
A corrosion test of hard facing material has been conducted in 600C sodium for 2000 hrs. Test pieces were Co base alloys, Ni base alloys and carbides which were provided for tribology studies in sodium. These materials were compared with SUS304, SUS316 and another corrosion and heat resisting alloys by simultaneous exposure. Analysis methods after exposure were as follows: surface roughness, hardness, corrosion rate, surface morphology and metallurgical structure which have influence on friction and self-welding behavior. The results obtained are as follows: (1)Stellitew alloys: Part of test pieces showed weight gain. Change of surface roughness was minute. Structural change was not observed in the surface vicinity of sodium contact. However, hardness increase was observed. (2)Ni base hard facing materials such as Colmonoy alloys: Corrosion rates were high and hardness was reduced. A degraded layer of 10m through 40m was observed on the surface of Colmonoy alloys and their surface roughness increased. (3)Inconel alloys: Corrosion rates were double those of stainless steels. A degraded layer of 1m through 4m was observed on the surface. Change in surface roughness was minute. (4)Corrosion and heat resisting alloys: Corrosion rates showed one to two times greater than those of stainless steels. Change in surface roughness was minute. No change in surface layer was observed. However, precipitates were observed in the metallurgical structures of some alloy types. (5)Carbides: Large increase of surface roughness was observed. LC-1C exhibited stripping from substratum. LW-1N40 indicated wide variation in corrosion rates. (6)Other materials: SUS316 produced a sigma phase at the grain boundary of sodium surface contact.
Kano, Shigeki; Maruyama, Akira*; *; *; Kawai, Masashi; Namekawa, Masaru; Nakasuji, Takashi
PNC TN941 77-90, 102 Pages, 1977/01
A series of tests have been conducted in relation to experimental estimation of corrosion behavior of AlSI Type-316 fuel cladding tube in high temperature flowing sodium. A present study relates to establish the difference of corrosion behavior between qualities of fuel cladding tubes. A kind of the second fabrication tube for JOYO (S-II) and two kinds of tubes used for JOYO MK-I core S-III and K-III) have been exposed to 650C sodium at a flow velocity of 3 m/sec for 5000 hrs. Also, corrosion data up to date at the Sodium Technology Section have been arranged by test variables to obtain basic information for design criterion relating to sodium corrosion of domestic fuel cladding tubes. The results obtained are as follows: (1)Corrosion behavior in sodium depended on qualities of fuel cladding tubes. The S-III tube showed the greatest corrosion rate among fuel cladding tubes tested. (2)Alpha phase, sigma phase and carbide disappearance layer were observed in the surface vicinity of sodium contact. However, sigma phase existed in bulk thickness of the S-III tube. (3)Carbon and nitrogen transferred to sodium from all fuel cladding tubes, but boron didn't. Denitrization content depended on initial nitrogen content in the tube. Decarburization content was nearly constant and didn't depend on initial carbon content in the tube. (4)It was clarified that corrosion data obtained at the Sodium Technology Section stood comparison with foreign data. A rate of thickness change was 3.5 m/year (max. variation: 25%) at JOYO design conditions (sodium temperature: 650C, cold trap temperature: 150C, Reynolds number: 55,000 and L/D: zero). (5)A literature survey showed that active carbon content in sodium was 0.1 ppm through 0.2 ppm, which was one of rate controlling factors in carbon transfer.
*; *; *; Nakasuji, Takashi
PNC TN941 77-186, 36 Pages, 1977/01
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 : 500C] [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.
Kano, Shigeki; Nakayama, Koichi; Hasegawa, Naruo; Koakutsu, Toru; Namekawa, Masaru; Nakasuji, Takashi; Atsumo, Hideo
PNC TN941 77-179TR, 48 Pages, 1977/01
Kano, Shigeki; Nakayama, Koichi; Hasegawa, Naruo; Koakutsu, Toru; Nakasuji, Takashi; Namekawa, Masaru; Atsumo, Hideo
PNC TN941 77-179, 48 Pages, 1977/01
PNC-TN941-77-179.pdf:2.55MBPNC-TN941-77-179TR.pdf:2.29MB
A series of experiments have been carried out to develop and screen friction and wear resistant materials used for sliding components of a sodium cooled reactor. Preceding studies 
clarified the short-term friction and wear characteristics of various materials in 450C sodium. A present study relates to clarify friction and wear behavior in argon environment, where a part of sliding components are located, and compare test data in room temperature argon with those in 450do sodium. The results obtained are as follows: (1)Static friction coefficients (s) in argon were almost lower than 0.2. They were apt to be lower than those in sodium. (2)Kinetic friction coefficients (k) in argon varied with load. The difference of k in argon and sodium depended on material combination. (3)Wear rates were remarkably high in argon. Wear rates of Colmonoy and Stellite were not detected in sodium, but were detected in argon. (4)Sliding surface was more roughened in argon, and hardness of sliding surface was almost lower in argon than in sodium. (5)There is the significant difference between friction and wear characteristics argon and those in sodium. Then, it is difficult that in-sodium behavior is estimated with in-argon data. (6)The above-mentioned difference in room temperature argon and 450C sodium will be greater when the test is carried out in higher temperature argon.
*; Nakasuji, Takashi; Atsumo, Hideo; Kohashi, Kazuyuki*; *
PNC TN951 76-15, , 1976/11
no abstracts in English
Kano, Shigeki; *; Nakayama, Koichi; Hasegawa, Naruo; Koakutsu, Toru; Atsumo, Hideo; Nakasuji, Takashi
PNC TN941 76-81, 25 Pages, 1976/07
A series of experiments in sodium environment have been carried out to develop and screen the friction and wear resistant materials used for sliding components of the sodium cooled reactor. The present study relates to the friction and wear characteristics of nickel-basealloy "Colmonoy" and cobalt-base alloy "Stellite" with respect to temperature, load, sliding velocity, sliding mode and sodium flushing. Also several experiments were carried out in argon and atmospheric environments, and they were compared with those in sodium. The results obtained were as follows : (1)As the sodium temperature is raised, the kinetic friction coefficient () of Stellite alloy becomes higher, but that of colmonoy alloy remains constant or is rather lower. The of Collmonoy alloy becomes lower by 540C sodium flushing. (2)Both static friction coefficient (
) and of Colmonoy alloy are lower than those of Stellite alloy in sodium environment. (3)The dependence of and upon the load is low in sodium environment. In argon the dependence of upon the load is not found, while varies according to the load. (4)The friction behavior is influenced by sliding mode. The in oscillating sliding is higher than that in one-directional continuous sliding. Also the sliding surface in oscillating sliding is more roughened. (5)The dependence of upon the sliding velocity is not found in sodium environment except for that in low velocity area. (6)The kinetic friction coefficient is apt to be higher in argon than in sodium. Also the wear rate is much higher in argon.
*; Nakayama, Koichi; Kano, Shigeki; Nakasuji, Takashi; Atsumo, Hideo
PNC TN941 76-32, 79 Pages, 1976/02
A series of friction and self-welding tests have been conducted for material selection of many contacting and sliding parts used in a fast breeder reactor, and the present experiment was investigated with respect to the variation of frictional behavior due to the difference of the principal composition such as nickel, cobalt contained in various Colmonoy alloys (No.2, 4, 6) and Stellite alloys (No.1, 6, 12). The following results were obtained through these experiments. (l)The difference of the basic composition such as Nickel or Cobalt showed the different frictional behavior. For instance, the behaviors cobalt basic materials dependedon sodium temperature and nickel basic materials showed a stable behavior of friction. (2)Hard facing materials combined with Type 316 SS indicated higher frictional coefficient than the same combination of hard facing materials, and they showed the tendency to easily gall. (3)Colmonoy No.2 and No.4 of nickel basic materials showed the stable and low frictional coefficient of 0.3, but it showed the increasing static coefficient of friction in sodium. Also, hard facing materials showed higher self-weldability when combined with Type 316 SS.
Kano, Shigeki; *; Namekawa, Masaru; Nakasuji, Takashi; Atsumo, Hideo
PNC TN941 76-17, 124 Pages, 1976/01
In relation to the experimental estimation of corrosion behavior of AISI Type-316SS fuel cladding tube in high temperature flowing sodium, we clarified the relationship for sodium corrosion as a function of oxygen concentration in the preceding report.. The present study has been carried out to establish the dependence of corrosion behavior on the quality of cladding tube and the temperature gradient in sodium. Two kinds of the second fabrication tubes for JOYO (S-II and K-II) and three kinds of tubes to be used for JOYO MK-I core (S-III, K-III and C) have been exposured in flowing sodium of 425C through 660C for 5000 hours. The results obtained are as follows: (1) The corrosion behavior in sodium is depend on the quality (differenee of chemical conpositions and refining) of cladding tube. S-III tube shows the greatest corrosion rate of all cladding tubes tested. The cavity which has been observated in the vicinity of the surface in contact with 650C sodium distributes over the whole thickness of S-III tube. The $alpha phase has been detected on the surface of S-II and S-III tubes but not on C tube. (2) The profile of corrosion rate along sodium flow under the continuous rise of sodium temperature shows the unique shape. It is different from the test result at the isothermal region in the vicinity of the outlet of heat exchanger. (3) The beginning temperatures of decarburization and denitrization have been obtained under the continuous rise of sodium temperature. The beginning temperature of decarburization is depend on the heat of cladding tube, while that of denitrization is depend on the initial nitrogen content of cladding tube. (4) The dependence of short-term tensile strength and hardness on the exposure temperature has been investigated at ambient temperature. S-III and K-III tubes show the high level (the higher the temperature rises, the greater the strength and the hardness become), while C tube shows the ...
