Onodera, Seiji; Hirose, Hideyuki; Izawa, Kazuhiko; Tanino, Shuichi; Kaminaga, Jota*; Sakuraba, Koichi; Miyauchi, Masakatsu; Tonoike, Kotaro; Miyoshi, Yoshinori; Yanagisawa, Hiroshi; et al.
JAERI-Tech 2001-057, 54 Pages, 2001/09
no abstracts in English
; ; Sakamoto, Naoki; *; ;
JNC-TN9400 2000-095, 110 Pages, 2000/07
The effects of high fluence irradiation and swelling on the transient burst properties of austenitic steel fuel claddings; PNC316 and 15Cr-20Ni stcel, which were irradiated as the MONJU type fuel assemblies (MFA-1&MFA-2) in the FFTF reactor, were investigated. The temperature-transient-to-burst tests were conducted on a total of eight irradiation conditions. Fractographic examination and TEM observation were performed in order to evaluate the effect of high dose irradiation on the transient burst property and the relation between failure mechanism and microstructural change during rapid (ramp) heating. The results of the PIE showed that there was no significant effect of irradiation on the transient burst properties of these fuel claddings under the irradiation conditions examined. the results obtained in this study are as follows; (1)The rupture temperature of the irradiated PNC316 fuel cladding of MFA-1 was as same as that of our previous works for the fluence range up to 2.1310 n/m. There was no noticeable decrease in rupture temperature with increasing fluence in lower hoop stress region(100MPa). (2)The rupture temperature of the irradiated 15Cr-20Ni fuel cladding of MFA-2 was almost as same as that of as-received cladding for the hoop stress range up to about 200MPa. The rupture temperature did not decrease significantly with fluence. (3)The rupture temperature of the irradiated PNC316 cladding tested at hoop stress 69MPa, which was the design hoop stress for MONJU fuel, was 1055.6C. This suggested that the design cladding maximum temperature limit for MONJU (830C) was conservative. (4)There was no obvious relation between rupture temperature, swelling and microstructural change during transient heating under the irradiation conditions examined.
JNC-TN9400 2000-041, 29 Pages, 2000/03
Irradiation behavior and performance models were investigated in order to apply for nitride fuel options in feasibility study on fast breeder reactor and related recycle systems. (1)MechanicaI design of nitride fuel pin: The behaviors of fission gas release (increase of internal Pressure) and fuel-to-cladding chemical interaction (decrease of cladding thickness) are needed to evaluate cumulative damage fraction in case of fuel pin mechanical design. The behaviors of fission gas release and fuel-to-cladding chemical interaction were investigated from the past studies up to high burnuP, since the lower fission gas release in nitride fuel than in oxide fuel could contribute to reduce the plenum volume and result in the shortening of fuel Pin length. (2)Fuel pin smear density: The higher fuel smear density is preferred for the higher fissile density to improve the core characteristic. The behaviors of fuel pellet swelling were investigated from the past studies up to higher burnup, since the larger fuel pellet swelling in nitride fuel than in oxide fuel would restrict high burunp capability due to fuel-cladding mechanical interaction. (3)Compatibility of nitride fuel with high Temperature water: Compatibility of nitride fuel with high temperature water were investigated from the past studies to contribute water cooled fast breeder reactor options.
JNC-TJ1420 2000-004, 159 Pages, 2000/03
no abstracts in English
Mizuta, Shunji; ;
JNC-TN9400 99-082, 60 Pages, 1999/10
The density measurement of the internal creep specimens irradiated in FFTF/MOTA (Fast Flux Test Facility / Material open Test Assembly) was conducted MMF (Materia1 Monitoring Facility) and accurate separation of swelling strain from total strain leaded in the derivation of the irradiation creep coefficients. Irradiation creep coefficients for PNC 316, 15Cr-20Ni base S.S. and 14Cr-25Ni base S.S. were systematically expressed, while thermal creep coefficients K, under irradiation were separately expressed for above three steels. The results obtained are follows, (1)The effect of stress induced swelling was recognized in the temperature range from 405 to 605C. The swelling in high stress specimens have a tendency to increasing swelling. (2)The irradiation creep coefficients derived from PNC316 and l5Cr-20Ni are similar to that of derived from 20%CW316S.S., CW316Ti and CW15-15Ti which were reported by other authors. (3)The irradiation creep coefficient derived from gas pressurized tube irradiation using FFTF/MOTA expressed appropriately irradiation creep strain from fuel pins using FFTF/MFA-2(15Cr-2ONi base S.S.).
PNC-TN9410 98-050, 57 Pages, 1998/05
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 ...
Matsumoto, Mitsuo; ;
PNC-TN1410 98-005, 96 Pages, 1998/03
no abstracts in English
PNC-TJ9601 98-005, 85 Pages, 1998/03
To fabricate a long life fuel cladding tubes for the fast breeder reactor, the concept of functionally graded material was applied for the material combination of molybdenum/stainless steel/ titanium, in which titanium is placed at the inner side to withstand against fission products and neutron irradiation, and molybdenum at the outer side to withstand corrosion by liquid sodium coolant. Slurry dipping method was employed for the processing because of its capability of shape forming and microstructural control. The graded layers of titanium and molybdenum were formed on both sides of stainless steel substrate according to an optimum composition profile for the thermal stress reduction. Such graded layers were successfully formed by slurry dipping. Dispersion, sedimentation, viscosity, rheology, as well as yield value, of the slurries were investigated in detail inconnection with properties of dispersion medium, dispersion reagent, binder and raw powders. Low- and high-viscosity slurries were investigated to enlarge a possibility of film thickness control. For the low-viscosity slurry it is necessary to suppress the sedimentation of dispersion particles, while for the high-viscosity slurry it turned out to be important to clarify the flow characteristics of the slurry for the determination of the yield value, which is needed for the precise control of the dip-coated layer thickness. The forming conditions were determined for the low-viscosity slurry in taking sedimentation rate and sedimentation height as measures of slurry stability and dispersion, respectively. It was confirmed that slow sedimentation and low sedimentation height gave reproducible film forming. The high-viscosity slurry was free from sedimentation, and the control of the film thickness with viscosity and yield value was rather easier. The consolidation Process of the dip-coated layer, including drying and debinding, followed conventional powder metallurgical techniques, with particular ...
Onuki, Norihiko; ; Shuji, Yoshiyuki; ; ; ;
PNC-TN8410 97-272, 134 Pages, 1997/08
PNC-TN1410 97-030, 107 Pages, 1997/08
no abstracts in English
PNC-TN1410 97-029, 65 Pages, 1997/08
no abstracts in English
PNC-TN1102 97-013, 45 Pages, 1997/07
no abstracts in English
PNC-TJ9601 98-004, 79 Pages, 1997/03
In order to obtain long life fuel cladding tubes for the fast breeder reactor, the concept of functionally graded material was applied for the material combination of Molybdenum/stainless steel/ Titanium, in which Titanium and Molybdenum were placed at the inner and outer sides, respectively. Slurry dipping method was employed because of its capability of shape forming and microstructural control. We have hitherto reported the design criteria for the graded layers, preparation of the slurry, and microstructural control of the dip-coated layers. In the present report, the thickness control of the dip-coated layer is described in detail. The thickness of the dip-coated layer depends primarily on the viscosity of the slurry. Nevertheless, for the stable dispersion of the powder in the slurry, which dominates the microstructural homogeneity, an optimum viscosity value is present for the individual slurries. With stable slurries of Ti, Mo, stainless steel powders and their mixtures, the thicknesses of dip-coated layers were controlled in dependence of their viscosities and yield values. For Ti and stainless steel powders and their mixture a PAANa was used as a dispersing agent. A NaHMP was found to be effective for the dispersion of Mo powder and Mo/stainless steel powder mixture. For all slurries tested in the present investigation PVA addition was helpful for the viscosity control. Dip-coating maps have been drawn for the stabilization of the slurries and for the formation of films with a sufficient strength for further manipulation for the slurries with low viscosity (10 mPas). The final film thickness for the low-viscosity slurry with the optimum condition was about 200m. The slurries with high viscosities of several hundreds mPa s had a good stability and the yield value was easy to be controlled. The film thickless was able to be adjusted in the size range between several tens and several hundreds m. The final thickness of the graded layer ...
PNC-TN9410 97-013, 111 Pages, 1997/01
Since the 54-rod cluster high-burnup fuel assemblies are planing to be loaded in Fugen, it must be confirmed that the mechanical integrity of the assemblies will be retained during the dwelling period in the reactor core. In the integrity verification, the confirmation that fretting wear, which occurs on fuel cladding surface at the contact with the spacer ring-elements, will not exceed the design margin is important. Accurate measurements of the flow-induced vibration characteristics under the hydraulic condition of coolant simulating the reactor core, especially measurements of the vibration amplitude, is necessary because the vibration amplitude directly affects the fretting wear depth. The flow-induced vibration measurements of the 54-rod cluster high-burnup fuels in which accelerometers were installed, were carried out under the various hydraulic conditions in the Component-Test-Loop (CTL). The results of the measurements are discribed in this papers. From the frequency analysis, the characteristic frequency of the fuel was observed around 105 Hz and 160 Hz. This frequency approximately coincided with that estimated by the fretting wear analysis code. The amplitude of flow-induced vibration was increased with increase in total flow rate and steam quality. Though these tendencies coincided with the results calculated by the analysis code, the amplitude measured at the region of low flow rate tended to be large compared with the calculated values. It was confirmed that this difference can be reduced on the safety side by the modification of the equation in the analysis code. The Paidoussis equation is divided into two terms in this modification, in which one term depending on total flow rate and the other term depending on steam quality, and proper coefficients are determined for each term. Though the amplitudes of flow-induced vibration for this fuel were larger than for either of the 28-rod cluster fuel of Fugen and 36-rod cluster fuel of ATR demonstration ...
; ; ;
PNC-TN8440 96-034, 109 Pages, 1996/07
; ; ; ; ; ;
PNC-TN9410 96-235, 258 Pages, 1996/03
The chemical decontamination technique has been developed in order to remove the crud adhering to the surface of the components constructing the primary coolant system, as a part of the measure to decrease the exposure in the annual inspection. The technique has been already applied to the prototype reactor "Fugen", in the core of which the fuel assemblies were not loaded. The chemical decontamination, for the core in which the fuel assemblies are loaded, has been planned for the purpose of improving the utilization factor. It is necessary to confirm, through the test before putting the plan into practice, that the decontamination reagent does not exert a bad influence upon the components constructing the fuel assembly. This report describes the test results which have been carried out so as to investigate the influence of the reagent on the components constructing the fuel assembly. The outline of the results is as follows: (1)The susceptibility to stress corrosion cracking of the chemical decontamination treatment and the residual decontamination reagent on the components constructing the fuel assembly is low enough. (2)The chemical decontamination treatment and the residual decontamination reagent do not exert a bad influence upon the integrity of the fuel assembly concerning the fuel rod holding function of the spacer and the characteristics of the fretting wear caused on the fuel claddings.
; ; ; ; ; ; Kaito, Yasuaki; ; ; ; et al.
PNC-TN2410 96-005, 339 Pages, 1996/03
Construction of the 'Monju' fuel handling systems was completed in April, 1992. From March 1991 to August 1992, pre-commissioning tests were carried out. In December 1992, all the systems of Monju were transfered to PNC, and commissioning tests and reactor physics tests, were started. For the first time, during these physics tests, the fuel handling systems were operated for one of the commissioning tests 'Loading to Criticality', without significant problems. 168 fuel sub-assemblies were loaded into the core and the first criticality was achieved on 5th April 1994. The fuel handling systems continued in operation for the 'Loading to Full Size of the Core', power distribution test and for cleaning discharged dummy sub-assemblies. To keep these fuel handling systems working somothly and satisfactorily annual maintenance has been carried out since 1992. This paper describes the operation and maintenance experience of fuel handling systems after the pre-commissioning tests and future study items for system reliability improvement.
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PNC-TN8410 96-037, 65 Pages, 1996/01
*; *; *; *; *; *; *
PNC-TJ9009 96-002, 172 Pages, 1995/10
PNC-TN8600 94-005, 132 Pages, 1994/08
no abstracts in English