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Kimura, Nobuyuki; ; ; ; Kamide, Hideki; Tokuhiro, Akira; Hishida, Koichi
JNC TN9400 2000-057, 60 Pages, 2000/05
JNC-TN9400-2000-057.pdf:2.11MB
ln experimental study for the thermohydraulics of fast reactor, a simple experiment with fine measurement has been desired for understanding of phenomena and for verification of computer code rather than mockup experiments of large scale. For such purposes quality of experimental data must be improved. ln the velocity measurement, instantaneous velocity profile will have great advances for the understanding of phenomena and for the verification of computer code. ln this report two methods of the velocity profile measurement are discussed; one is ultrasound Doppler velocimetry (UDV) and the other is particle image velocimetry (PIV). These methods were applied to water experiments. The UDV was applied to pipe flow, planer jet, and the inter-wrapper flow which is seen in the gap region between subassemblies of fast reactor core. Cross check with laser Doppler velocimetly showed proper measurement of the UDV. Problems including the application to sodium experiments are also discussed. The PIV was also applied to the inter-wrapper flow. For the application to complex flow geometry, noise reduction method was developed to improve the measurement accuracy.
Mizuta, Shunji; ;
JNC TN9400 2000-048, 28 Pages, 2000/04
JNC-TN9400-2000-048.pdf:0.64MB
ODS (Oxide Dispersion Strengthened) ferritic-martainsitic steels are one of the most prospective cladding materials for advanced fast breeder reactors, since they are expected to have excellent swelling resistance and superior high temperature strength due to the finely distributed stable oxide particles(Y
O
). Properties and the tentative strength equations for ODS ferritic-martainsitic were proposed on the basis of the latest data to apply to the feasibility study of the sodium coolant MOX fuel plant. The items of equations are follows. (1)creep rupture strength (2)correction factor of creep rupture strength (in Na and in reactor) (3)outer surface eorrosion (Na) (4)inner surface corrosion (in MOX fuel pin) (5)thermal conductivity
Tsukimori, Kazuyuki; Furuhashi, Ichiro*
JNC TN9400 2000-049, 93 Pages, 2000/03
JNC-TN9400-2000-049.pdf:2.82MB
lt is one of the important key points to reduce thermal stress of the primary piping system in the design of sodium coolant loop-type FBR plants. The objectives of this study are to understand the characteristics of the thermal stresses in the simple S-shaped hot leg piping systems which run from the outlet nozzle of the reactor vessel (R/V) to the inlet nozzle of the intermediate heat exchanger (IHX), and to propose some recommendable routings of piping systems. Results are summarized as follows. (1)Generally, the thermal stresses in elbows are severer than those at nozzles. The tendency was observed that the stress in elbow decreases with the increase of the distance between the outlet nozzle of R/V and the inlet nozzle of IHX and also the distance between the outlet nozzle of R/V and the liquid surface level. (2)lt is expected to reduce thermal stresses in elbow to big extent by adopting super 90 degree elbows. Therefore, in these cases the dimension region which satisfies the allowable stress is broad compared with that in the case of the conventional 90 degree elbow. (3)The stress estimations in elbow based on 'MITl notice No.501' become excessively large compared with the results by FEA using shell elements, when the maximum stress occurs at the end of elbow. ln these cases, the estimation can be rationalized by replacing the maximum stress by the mean of stresses at the end and at the middle of the elbow. (4)Two routings with 105 degree elbows are recommended. 0ne has the advantage from the view point of reduction of length of pipe and the other does from the view point of reduction of thermal stresses, compared with the routing with 90 degree elbows.
*; *; *; *
JNC TJ3410 2000-020, 80 Pages, 2000/03
JNC-TJ3410-2000-020.pdf:41.34MB
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 605
C. 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.).
JNC TN9400 99-041, 187 Pages, 1999/05
lt is widely recognized that the current seismic design methods for piping involve a large amount of safety margin. From this viewpoint, a series of seismic analyses and evaluations with various design codes were made on typical LMFBR main sodium piping systems. Actual capability against seismic loads were also estimated on the piping systems. Margins contained in the current codes were quantified based on these results, and potential benefits and impacts to the piping seismic design were assessed on possible mitigation of the current code allowables. From the study, the following points were clarified; (1)A combination of inelastic time history analysis and true(without margin) strength capability allows several to twenty times as large seismic load compared with the allowable load with the current methods. (2)The new rule of the ASME is relatively compatible with the results of inelastic analysis evaluation. Hence, this new rule might be a goal for the mitigation of seismic design rule. (3)With this mitigation, seismic design accommodation such as equipping with a large number of seismic supports may become unnecessary.
Jitsukawa, T.*; Tojo, T.*; Takagi, M.*; Sudo, H.*
PNC TJ8674 95-001, 68 Pages, 1995/02
no abstracts in English
Tsutani, Sadahiro*; Takeshita, Hiroshi*; Edajima, Toshikazu*; Motooka, Masafumi*
PNC TJ8224 93-001, 128 Pages, 1993/06
no abstracts in English
Tanaka, Yoji*; Nakasawa, Otohiko*; Sugumoto, Hiroshi*; Takeshita, Hiroshi*
PNC TJ8224 92-002, 33 Pages, 1992/03
no abstracts in English
Tanaka, Yoji*; Nakasawa, Otohiko*; Sugumoto, Hiroshi*; Takeshita, Hiroshi*
PNC TJ8224 92-001, 108 Pages, 1992/03
no abstracts in English
; ; Kawata, Tomio
PNC TN8410 92-012, 47 Pages, 1991/12
[Purpose] We confirmed that modified (6000rpm type) centrifugal clarifier arose the unstable vibration during the reduction of rotating speed under the condition of bearing undissolved residue after the clarification operation. This report describes the cause of unstable vibration that arise in the clarification body set on the rack which induced resonance vibration and the measurement results of vibration characteristic after taking countermeasure for vibration decrease. [Method] It was considered that the causes of the unstable vibration were following; (1)Unbalance between damping force of the lower bearing damper and the vibration force arisen by the rotational bowl (2)Effect of feed condition (3)Effect of self-excited vibration of the free liquid surface (4)Effect of frame strength The test has been conducted to make quantitative measure of vibration characteristic (amplitude of the rotational bowl and shaft) by changing the load in the rotational bowl. We also conducted the test to reconfirm the effect of the circumferential baffle plate which has shown the most effective effect to the vibration decrease in the preceding report. [Results] The effects of the circumferential baffle plate placed on the inside wall of the rotational bowl are shown as follows; (1)The unstable vibration during the reduction of rotating speed has been suppressed By this result, we verified that the vibration on the free liquid surface in the rotational bowl caused the vibration for the bowl without the circumferential baffle plate. (2)It was able to run the clarification operation in the standard condition(100
/h 
6h) for the rotational speed ranging from 4000 to 6000rpm. [Conclusion] By the results of this test and of the preceding report, the feed condition and the condition of setting the circumferential baffle plate are showed in the following, considering the aspects of rotational stability. (1)Condition of feed nozzle - feed 55㎜ in height from the lower ...
; ;
PNC TN9410 91-169, 87 Pages, 1991/08
We have been developing a inspection tool in order to apply for ISl of 32B sized elbow piping on MONJU primary cooling circuit. Experiments and examination were carried out on design work to decide the design parameters. We obtained the results as follows, (1)The design parameters of un ultrasonic probe, such as the ultrasonic element's diameter, frequency and refraction angle, were chosen as the most suitable for fraw detection. (2)It was confirmed that the most stable scanning of the scanner was achieved by the control of 3 driving wheels. (3)The scanner could be carried by 2 persons, it's weight was 38kg. (4)The handling mechanism for thermal insulator consist's of three divided piecies and lt's driving source is pneumatic. The conclusions of this study were as follows, (1)An equipments of the volumetric examination for large scale elbow piping was designed, and it could be use at 80C without supplying and collecting apparatus for couplant. (2)This system must be contribute the reduction of human radiation dose.