; *; ; ; Aoto, Kazumi;
JNC-TN9400 2000-059, 43 Pages, 2000/05
The purpose of this study is to understand the material properties of manufacturable high-purity iron and high-purity iron-based alloy in present technology and to get an applicable prospect for the structural and functional material of the frontier fast reactor. Then the about 10kg high-purity iron and iron-based alloy were melted using a cold-crucible induction melting furnace under the ultra-high vacuum. Subsequent to that, the compatibility between the melted material and the high-temperature sodium environment which is a special feature of the fast reactor and tensile property at room and elevated temperatures were investigated using the melted materials. Also, the creep test using the high-purity 50%Cr-Fe alloy at 550C in air in order to understand the high temperature creep property. ln addition, the material properties such as thermal expansion coefficient, specific heat and electrical resistance were measured and to evaluate the outlook for the structural material for the fast reactor. The following results were obtained based on the property test and evaluation. (1)lt was possible to melt the about 10kg high-purity ingot and high-purity 50%Cr-Fe alloy ingot using a cold-crucible induction melting furnace under the ultra-high vacuum. (2)The tensile tests of the high-purity 50%Cr-Fe alloy were performed at room and elevated temperatures in order to understand the deformation behavior. From the experimental results, it was clear that the high-purity 50%Cr-Fe alloy possesses high strength and good ductility at elevated temperatures. (3)The physical properties (the thermal expansion coefficient and specific heat etc.) were measured using the high-purity 50%Cr-Fe alloy. lt was clear that the thermal expansion coefficient of high-purity 50%Cr-Fe alloy was smaller than that of SUS304. (4)From the corrosion test in liquid sodium, the ordinary-purity iron showed the weight loss after corrosion test. However the high-purity iron showed ...
; Washiya, Tadahiro;
JNC-TN8420 2001-009, 48 Pages, 2000/04
ICONE(International Conference on Nuclear Engineering) is an international conference on nuclear chemical engineering held among the United States, Japan and Europe, and ICONE8 (the 8th time of the conference) was held at Baltimore, USA on April 2 to 6, 2000. The authors of this paper reported the latest information on the reprocessing technology in the following session of the conference and audited the panel discussion and the technical report of the dry reprocessing technology etc. in the conference. (1)Investigation of Safety Evaluation Method and Application to Tokai Reprocessing Plant (TRP) in session of Track-5 "Non-reactor Safety and Reliability" (Nakamura) (2)Structural Improvement on the continuous rotary dissolver in session of Track-9 "Spent Nuclear Fuel and Waste Processing" (Washiya) (3)Development of Evaporators Made of Ti-5% Ta Alloy and Zr - Endurance Test By Mock-Up unit" in session of Track-2 "Aging and Modeling of Component Aging, Including corrosion of Metals and Welds.. passivation, and passive films" (Takata) At the conference, about 650 people participated from the United States, Japan, France, Canada and others, about700 research announcements, 7 keynote lecture and 8 panel discussion were done, flourishing with many participants. Moreover, as the conference was held in the year of 2000, the evaluation of this century and the direction of the next century of nuclear energy were discussed. After the conference, authors visited Argonne National Laboratory (ANL-E, ANL-W) and exchanged information concerning dry process with researchers of ANL-E and ANL-W, visiting ANL facilities. It was very significant to be able to acquire the information on the dry process developed in ANL and realize the device scale and the development environment, etc. and acquire technical information in detail which would not be able to obtain by engineering data, exchanging information with ANL engineers directly. It is suggested to be very valuable that the ...
JNC-TN9420 2000-005, 28 Pages, 2000/03
In the first phase of the feasibility study, their basic objectives are presentating the feasible image and scenario of development of the FBR cycle system, which is composed of the fast reactor, spent fuel reprocessing and fuel manufacturing facility. In the development of the FBR system in this phase, various ideas of plants are to be studied, which include coolant types such as sodium, heavy metals, gases(CO, He), wator, and middle or small size of the reactor, and fuel types (MOX, metal and nitride). In this report, as a part of this study, materials used for the core of the helium gas cooled reactor and their integrity (corrosion, mechanical and irradiation property) under high temperature helium atmosphere were investigated from open literatures.
*; *; Tanai, Kenji
JNC-TN8400 99-049, 94 Pages, 1999/11
This paper reports the results of design analysis and trial manufacturing of copper-carbon steel composite overpacks. The overpack is one of the key components of the engineered barrier system, hence, it is necessary to confirm the applicability of current technique in their manufacture. The Copper-Carbon steel composite overpack consists of a double container, an outer vessel made of oxygen-free, high-purity copper as the corrosion allowance material, and an inner vessel made of carbon steel as the pressure-resistant material. The trial manufacturing in this time, only the copper outer vessel has been fabricated. Both oxygen-free copper and oxygen-free phosphorus copper were used as materials for the outer vessel. For the shell and bottom portion, these materials were formed integrally by a backward extrusion method. For sealing the top cover plate to the main body, an electron-beam welding method was applied. After manufacturing, mechanical testing of specimens from the copper vessels were carried out. It was confirmed that current technique has sufficient feasibility to manufacture outer vessel. In addition, potential for irradiation embrittlement of the inner carbon-steel vessel by irradiation from vitrified waste over the life time of the overpack has been analyzed. It was shown that the small degree of irradiation embrittlement gives no significant impact on the pressure resistance of the carbon-steel vessel. Future research and development items regarding copper-carbon steel composite overpacks are also discussed.
*; *; Tanai, Kenji
JNC-TN8400 99-047, 54 Pages, 1999/11
This paper reports on the design process for a carbon-steel overpack as a key component in the engineered barrier system of a deep geological repository described in the 2nd progress report. The results of the research and development regarding design requirements, configuration, manufacturing and inspection of overpack are also described. The concept of a composite overpack composed of two different materials is also considered. First, the design requirements for an overpack and presume environmental and design conditions for a repository are provided. For a candidate material of carbon steel overpack, forging material is selected considering enough experience of using this material in nuclear power boilers and other components. Second, loading conditions after emplacement in a repository are set and the pressure-resistant thickness of overpack is calculated. The corrosion thickness to achieve an assigned 1000 year life time and the required thickness to prevent radiolysis of ground water which might enhance corrosion rate are also determined. As aresult, the total required thickness of a carbon-steel overpack is conservatively estimated to 190 mm. This is a reduction of about 30% from the previous estimate provided in the 1st Progress Report. Additional items that must be considered in manufacturring and operating overpacks (i.e. sealing of vitrified waste, examination of main body and sealing welding, mechanism of handling) are evaluated on the basis of current technology, specific future data needs are identified. With respect to the concept of composite overpack (i.e., an outer vessel to provide corrosion-allowance or corrosion-resistant performance and an inner vessel to provide pressure-resistance), the differences in design concepts between the carbon-steel overpack and such composite overpacks are analyzed. Future data needs and analytical capabilities with respect to overpacks are also summarized.
JNC-TN9400 99-035, 37 Pages, 1999/04
In sodium environment, materia1 316FR stainless steel risks to suffer from carburization. In this study, an analysis using a Fortran program is conducted to evaluate the carbon influence on the creep behavior of 316FR based on experimental results from uni-axial creep test that had been performed at temperature 550C in sodium environment simulating Fast Breeder Reactor condition. As performed in experiments, two parts are distinguished. At first, elastic-plastic behavior is used to simulate the fact that just before the beginning of creep test, specimen suffers from load or stress much higher than initial yield stress. In second part, creep condition occurs in which the applied load is kept constant. The plastic component should be included, since stresses increase due to section area reduction. For this reason, elastic-plastic-creep behavior is considered. Through time carbon penetration occurs and its concentration is evaluated empirically. This carburization phenomena are assumed to affect in increasing yield stress, decreasing creep strain rate, and increasing creep rupture strength of material. The model is capable of simulating creep test in sodium environment. Material near from surface risks to be carburized. Its material properties change leading to non-uniform distribution of stresses. Those layers of material suffer from stress concentration, and are subject to damage. By introducing a damage criteria, crack initialization can thus be predicted. And even, crack growth can be evaluated. For high stress levels, tensile strength criterion is more important than creep damage criterion. But in low stress levels, the latter gives more influence in fracture. Under high stress, time to rupture of a specimen in sodium environment is shorter than in air. But for stresses lower than 26 kgfmm, the time to rupture of creep in sodium environment is the same or little longer than in air. Quantitatively, the carburization effect at ...
Kasahara, Naoto; Yacumpai, A.*; Takasho, Hideki*
JNC-TN9400 99-019, 34 Pages, 1999/02
At incomplete mixing area of high temperature and low temperature fluids near the surface of structures, temperature fluctuation of fluid gives thermal fatigue damage to wall structures. This thermohydraulic and thermomechanical coupled phenomenon is called thermal striping, which has so complex mechanism and sometimes causes crack initiation on the structural surfaces that rational evaluation methods are required for screening rules in design codes. In this study, frequency response characteristics of structures and its mechanism were investigated by both numerical and theoretical methods. Based on above investigation, a structural response diagram was derived, which can predict stress amplitude of structures from temperature amplitude and frequency of fluids. Furthermore, this diagram was generalized to be the Non-dimensional structural response diagram by introducing non-dimensional parameters such as Biot number, non-dimensional frequency, and non-dimensional stress. The use of the Non-dimensional structural response diagram appears to evaluate thermal stress caused by thermal striping, rapidly without structural analysis, and rationally with considering attenuation by non-stationary heat transfer and thermal unloading. This diagram can also give such useful information as sensitive frequency range to adjust coupled thermohydraulic and thermomechanical analysis models taking account of four kinds of attenuation factors: turbulent mixing, molecular diffusion, non-stationaly heat transfer, and thermal unloading.
PNC-TN9410 98-059, 53 Pages, 1998/06
The analysis program code STEDFAST; Space, TErrestrial and Deep sea FAST reactor ・gas turbine system; had been developed in PNC to get the best values of system parameters on fast reactor ・gas turbine power generation systems used as power sources for deep sea, space and terrestrial cogeneration. In this report, we performed a parameter survey analysis by using the code to study characteristics of the systems. Concerning the deep sea fast reactor ・gas turbine system, calculations with many variable parameters were performed on the base case of a NaK cooled reactor of 40kWe. We aimed at total equipment weight and surface area necessary to remove heat from the system as important values of the characteristics of the system Electric generation power and the material of a pressure hull were specially influential for the weight. The electric generation power, reactor outlet/inlet temperatures, a natural convection heat transfer coefficient of sea water were specially influential for the area. Concerning the space reactor ・gas turbine system, the calculations with the variable parameters of compressor inlet temperature, reactor outlet/inlet temperatures and turbine inlet pressure were perfomed on the base case of a Na cooled reactor of 40kWe. The first and the second variable parameters were influential for the total equipment weight of the important characteristic of the system. Concening the terrestrial fast reactor ・gas tubine system, the calculations with the variable parameters of heat transferred pipe number in a heat exchanger to produce hot water of 100 C for cogeneration, compressor stage number and the kind of primary coolant material were performed on the base case of a Pb cooled reactor of 100MWt. In the comparison of calculational results for Pb and Na of primary coolant material, The primary coolant weight flow rate was naturally large for the fomer case compared with for the latter case because density is very different between them. ...
*; *; *
PNC-TJ9603 98-002, 48 Pages, 1998/03
[PURPOSE]Both the Nb-based and Mo-based alloys have been designed and developed in order to establish the frontier technique for super-heat-resisting materials used in the liquid alkali metal environment at high temperatures. In this study, mechanical properties of the designed Nb-1Hf alloy were experimentally evaluated. In addition, the brittleness of Nb-based alloys observed at 1073K were discussed. Moreover, characteristics of both the designed Nb-based and the Mo-based alloys were summarized in a consistent way. [EXPERIMENTAL METHODS] (1)Tensile test : The tensile test was performed at room temperature and 1473K in an Ar gas atmosphere for the designed Nb-1Hf alloy and also for commercial Nb-1Zr alloy. (2)High temperature creep test:The creep test of the designed Nb-1Hf alloy was carried out at 1473K in an Ar gas atmosphere under several applied stress levels. (3)TEM observation : The TEM observation was performed with the creep specimens tested at both 1073K and 1273K in order to get information for the 1073K brittleness of the Nb-1Zr alloy. [RESULTS AND DISCUSSIONS] (1)Tensile test : The tensile stress and the proof stress of the designed Nb-1Hf alloy were slightly lower than those of commercial Nb-1Zr alloy at room tempetarure. But the alloy was superior in the elongation to the Nb-1Zr alloy. High temperature tensile properties were not able to be evaluated properly because of the large grain size of the specimens. (2)High temperature creep test : The Nb-1Hf alloy was superior in the ereep resistance to other solid solution hardened Nb-based alloys. (3)TEM observation : A modulated structure with about 1nm preiod was observed in the specimen which was brittle at 1073K. This was supposed to cause the 1073K brittleness of the Nb-1Zr alloy. [CONCLUSION] The tensile strength of the designed Nb-1Hf alloy was slightly lower at room temperature than that of the commercial Nb-1Zr alloy. But, the designed alloy was superior in high temperature creep properties to any
Hyojun Busshitsu; Bunseki, Keisoku No Shinraisei Kakuho No Tameni, p.175 - 178, 1998/00
no abstracts in English
*; *; ; Takeda, Seiichiro
PNC-TN8410 97-433, 50 Pages, 1997/12
; ; *; ; Takeda, Seiichiro
PNC-TN8410 97-425, 34 Pages, 1997/11
PNC-TN1102 97-013, 45 Pages, 1997/07
no abstracts in English
Aoto, Kazumi; ; ; ; ;
PNC-TN9420 97-007, 786 Pages, 1997/06
The results of the research on the damaged thermocouple well which caused the sodium leak accident at the outlet of the C-loop intermidiate heat exchanger (IHX) of the secondary heat transfer system of the prototype fast breeder reactor Monju are described in this report. A lot of tests, inspections, observations and measurements were carried out to confirm that the thermocouple well and its attachments to the pipe including welded part are normal by checking the possibility of weld failure or corrosion at the clearance which may cause the damage of the thermocouple well, and to get information of the dimensions relating the estimation of the leaked sodium volume and the leakage path, etc. These tests, etc., were performed for the thermocouple well except the fractured surface, the thermocouple well, the welded parts between the thermocouple well and the attachment, and between the attachment and the outlet pipe, etc., as written below. (1)Accurate measurement of the dimension. (2)Inspection to check the fixing condition between the thermocouple well and the attachment. (3)Measurement of the residual stress. (4)Non destructive testing at some points. (5)Chemical composition analysis. (6)Microscopic observation of metalogical structure at the welded part. (7)Hardness test. (8)Research on corrosion at the clearance. (9)Structure strength test of the thermocouple well. (10)Bending test of the thermocouple's sheath at high temperature.
PNC-TN9430 97-003, 17 Pages, 1997/05
The database system named "Data Free Way (DFW)" has been constructed in collaboration with PNC, NRIM, JAERI and JST, and a lot of materials data have been stored in DFW with its improvements. Experimental and literature data on corrosion behaviors of ceramics and refractory metals based alloys against alkali metals have been inputted in DFW of PNC site. The DFW system and the network situation around it have been improved to retrieve distributed database by using Internet. The WWW server has been set in DFW machine for client-server system and user's interface has been developed in order to retrieve the database through WWW browser. The DFW server machine of PNC has been set outside of seculity system called firewall for access from other organizations directly, and the local area network of DFW (DFW-LAN) has been constructed to be possible to use and maintain DFW system through the PNC main network. This consists of some personal computers, which play part in preparation, input and analysis of database, instead of engineering workstation. These improvements have brought more effective value to DFW as a advanced material database system.
Aoto, Kazumi; ;
PNC-TN9410 97-037, 51 Pages, 1996/11
The basic material properties of a rolled steel for welded structure (present standard name is SM400B, old standard name SM41B) which is used as the liner plate in SHTS cells of "Monju plant". Based on the material testing data for evaluation of structural integity of the liner during sodium leakage are tentatively proposed. Main basic material properties are shown as follows. (1)The 0.2% offset yield stress (lower yield point). (2)The ultimate tensile strength. (3)The modulus of the longitudinal elasticity. (4)Static stress-strain relation. (Physical property in Ludwik equation). (5)The creep strain. (6)The linear thermal expansion coefficient. (7)The density. (8)A specific heat. (9)The thermal conductivity.
Power Reactor and Nuclear Fuel Development Corporation
PNC-TN9360 95-002, 98 Pages, 1995/11
no abstracts in English
*; *; Murata, Yoshinori*; ; *; ; Inoue, Satoshi*
PNC-TY9623 95-001, 165 Pages, 1995/03
PNC-TJ1211 95-003, 38 Pages, 1995/02