JOPSS - Search Results

Sodium fire analyses were performed on 7 kinds of sodium leak tests using a computer code ASSCOPS which has been developed to evaluate thermal consequences of sodium leak accident in an FBR plant. By the comparison between the calculated and the test results of gas pressure, gas temperature, sodium catch pan temperature, wall temperature, and of oxygen concentration, it was confirmed that the ASSCOPS code and the parameters used in the analysis give valid or conservative results on thermal consequences of sodium leak and fire.

JAEA Reports

Sodium combustion analysis for the secondary heat transport system of prototype fast breeder reactor MONJU

; Ohno, Shuji;

JNC TN2400 2000-006, 56 Pages, 2000/12

JNC-TN2400-2000-006.pdf:1.22MB

Sodium combustion analyses were performed using ASSCOPS version 2.1 in order to obtain background data for evaluating the validity of the mitigation system against secondary sodium leak of MONJU. The calculated results are summarized as follows. (1)Peak atmospheric pressure 4.3 kPa[gage] (2)Peak floor liner temperature 870 $^{circ}$ C, Maximum thinning of liner 2.6mm (3)Peak hydrogen concentration <2% (4)Peak floor liner temperature in the spilt sodium storage eell 400 $^{circ}$ C , Peak floor concrete temperature in the spilt sodium storage cell 140 $^{circ}$ C.

JAEA Reports

Mechanical integrity of floor liner in secondary heat transport system cells of Monju

; ; Ueno, Fumiyoshi; ; ; ;

JNC TN2400 2000-005, 103 Pages, 2000/12

JNC-TN2400-2000-005.pdf:3.98MB

Inelastic analyses of the floor liner subjected to thermal loading due to sodium leakage and combustion were carried out, considering thinning of the liner plate due to molten salt type corrosion. Because the inelastic strain obtained by the analyses stayed below the ductility limit of the material, mechanical integrity, i.e., there exist no through-wall crack on the floor liner, was confirmed. Partial structural model tests were conducted, with a band of local thinning of the liner plate. Displacements were controlled to give specimens much larger strains than those obtained by the inelastic analyses above. No through-wall crack was observed by these tests. Mechanical integrity of the floor liner was confirmed by these results of the inelastic analyses and the partial structural model tests.

JAEA Reports

CompalisonoFnlermohydraulicCharacteristicsintheuseofvariousCoolants

; ; *; Yamaguchi, Akira

JNC TN9400 2000-109, 96 Pages, 2000/11

JNC-TN9400-2000-109.pdf:9.56MB

Numerical calculations were carried out for a free surface sloshing, a thermal stratification, a thermal striping, and a natural convection as key phenomena of in-vessel thermohydraulics in future fast reactor systems with various fluids as coolants. This numerical work was initiaied based on a recognition that the fundamental characteristics of the phenomena have been unsolved quantitatively in the use of various coolants. From the analysis for the phenomena, the following results were obtained. [Free Surface Sloshing phenomena] (1)Ther is no remarkable difference betweeen liquid sodium and luquid Pb-Bi in characteristics of internal flows and free surface charatristics based on Fr number. (2)the AQUA-VOF code has a potentiall enough to evaluate gas entrainment behavior from the free surface including the internal flow characteristics. [thermal Stratification Phenomena] (1)On-set position of thermal entainment process due to dynamic vortex flows was moved to downstream direction with decreasing of Ri number. 0n the other hand, the position in the case of C0 $_{2}$ gas was shifted to upstream side with decreasing of Ri number. (2)Destruction speed of the thermal stratyification interface was dependent on thermal diffusivity as fluid properties. therefor it was concluded that an elimination method is necessary for the interface generated in C0 $_{2}$ gas. [thermal Striping Phenomena] (1)Large amplitudes of fluid temperature fluctuations was reached to down stream area in the use of CO $_{2}$ gas, due to larger fluid viscosity and smaller thermal diffusivity, compared with liquid sodium and liquid Pb-Bi cases. (2)To simulate thermal striping conditions such as amplitude and frequency of the fluid temperature fluctuations, it isnecessary for coincidences of Re number for the amplitude and of velocity value for the frequency, in various coolants. [Natural Convection Phenomena] (1)Fundamental behavior of the natural convection in various coolant follows buoyant jet ....

JAEA Reports

None

JNC TN1400 2000-012, 250 Pages, 2000/11

JNC-TN1400-2000-012.pdf:10.18MB

no abstracts in English

JAEA Reports

Inspection procedure of MONJU fuel pellet

Kajiyama, Tadashi;

JNC TN8410 2000-015, 7 Pages, 2000/10

JNC-TN8410-2000-015.pdf:0.09MB

Some falsification has been detected in the results of quality control data relating to the diameter of samples of pellets produced in the BNFL's MOX Demonstration Facility (MDF) on September 1999. This document is the outlines of inspection procedure for the MONJU fuel pellet in plutonium fuel center of JNC.

JAEA Reports

None

JNC TN1400 2000-010, 70 Pages, 2000/10

JNC-TN1400-2000-010.pdf:2.87MB

no abstracts in English

JAEA Reports

None

; Inagaki, Tatsutoshi*

JNC TY1400 2000-004, 464 Pages, 2000/08

JNC-TY1400-2000-004.pdf:19.55MB

None

JAEA Reports

Feasibility studies on commercialized fast breeder reactor cycle system (Phase I) interim report

; Inagaki, Tatsutoshi*

JNC TY1400 2000-003, 92 Pages, 2000/08

JNC-TY1400-2000-003.pdf:3.9MB

Japan Nuclear Cycle Development Institute (JNC) and Japan Atomic Power company (JAPCO, that is the representative of the electric utilities in Japan) have established a new organization to develop a commercialized fast breeder reactor (FBR) cycle system since July 1, 1999 and feasibility studies (F/S) have been undertaken in order to determine the promising concepts and to define the necessary R&D tasks. In the first two-year phase, a number of candidate concepts will be selected from various options, featuring innovative technologies. In the F/S, the options are evaluated and conceptual designs are examined considering the attainable perspectives for following: (1) ensuring safety, (2) economic competitiveness to future LWRs, (3) efficient utilization of resources, (4) reduction of environmental burden and (5) enhancement of nuclear non-proliferation. The F/S should also guide the necessary R&D to commercialize FBR cycle system.

JAEA Reports

Irradiation tests report of the 35th cycle in "JOYO"

JNC TN9440 2000-008, 79 Pages, 2000/08

JNC-TN9440-2000-008.pdf:2.33MB

This report summarizes the operating and irradiatlon data of the experimental reactor "JOYO" 35th cycle. Irradiation tests in the 35th cycle are as follows: (1)C-type irradiation rig (C4F) (a)High burnup performance test of advanced austenitic stainless steel cladding fuel pins (in collaboration with France) (2)C-type irradiation rig (C6D) (a)Large diameter fuel pins irradiation tests (3)Core Materials Irradiation Rig (CMIR-5) (a)Cladding tube materials irradiation tests for "MONJU" (4)Structure Materials Irradiation Rigs (SMIR) (a)Decision of material design base standard of structure materials for prototype reactor and large scale reactor (5)Upper core structure irradiation Plug Rig (UPR-1-5) (a)Upper core neutron spectrum effect and accelerated irradiation effect (6)SurVeillance un-instrument Irradiation Rig (SVIR) (a)Confimation of surveillance irradiation condition for "JOYO" (b)Material irradiation tests (based on a contract with universities) The maximum burnup driver assembly "PFD253" reached 67,600 MWd/t (pin average).

JAEA Reports

Sodium pooI combustion Test (Run-F7-3 and Run-F8-1) to confirm the condition of floor liner's corrosion

; ; Ohno, Shuji;

JNC TN9400 2000-092, 247 Pages, 2000/08

JNC-TN9400-2000-092.pdf:20.29MB

Small-scale sodium pool combustion tests Run-F7-3 and Run-F8-1 were performed to investigate the corrosion of floor liner under high moisture condition. ln the both tests, which were performed using the 3m $^{3}$ FRAT-1 vessel at the SAPFIRE facility, the sodium of 507deg-C was leaked on the carbon steel catch pan about for 25 minutes with the flow rate of around 25 kg/h. The air in the vessel was ventilated with the flow rate of 5m $^{3}$ /min containing the moisture of 25000-28000 vol.ppm. The duration of combustion was different in two tests by changing the starting time of argon gas injection into the vessel. As the results of post-test analysis such as observation of catch pan surface and chemical analysis of the deposits, it was confirmed that 'Na-Fe double oxidization type corrosion' was dominant in the both tests and that the catch pan and deposits were not under the condition leading to the occurrence of 'molten salt type corrosion.'

JAEA Reports

None

JNC TN1440 2000-007, 115 Pages, 2000/08

JNC-TN1440-2000-007.pdf:4.45MB

no abstracts in English

JAEA Reports

None

JNC TN1440 2000-005, 214 Pages, 2000/08

JNC-TN1440-2000-005.pdf:13.81MB

no abstracts in English

JAEA Reports

Analyse on the BFS critical experiments; An analysis on the BFS-62-1 assembly

Sugino, Kazuteru; Iwai, Takehiko*;

JNC TN9400 2000-098, 182 Pages, 2000/07

JNC-TN9400-2000-098.pdf:5.74MB

In order to support the Russian excess weapons plutonium disposition, the international collaboration has been started between Japan Nuclear Cycle Development Institute (JNC) and Russian Institute of Physics and Power Engineering (IPPE). In the frame of the collaboration, JNC has carried out analyses on the BFS-62 assemblies that are constructed in the fast reactor critical experimental facility BFS-2 of IPPE. This report summarizes an experimental analysis on the BFS-62-1 assembly, which is the first core of the BFS-62 series. The core contains the enriched U0 $_{2}$ fuel surrounded by the U0 $_{2}$ blanket. The standard analytical method for fast reactors has been applied, which was used for the JUPITER and other experimental analyses. Due to the lack of the analytical data the 2D RZ core calculation was mainly used. The 3D XYZ core calculation was applied only for the preliminary evaluation. Further in terms of the utilization of the BFS experimental analysis data for the standard data base for FBR core design, consistency evaluation with JUPITER experimental analysis data has been performed using the cross-section adjustment method. As the result of analyses, good agreement was obtained between calculations and experiments for the criticality and the reaction rate ratio. However, it was found that accurate evaluation of the reaction rate distribution was impossible without exact consideration of the arrangement of the two types of sodium (with and without hydrogen impurity), which can be accommodated by the 3D core analysis, thus it was essentia1. In addition, it was clarifie that there was a room for an improvement of the result on the reaction rate distribution in the blanket and shielding regions. The application of the 3D core calculation improved the result on the control rod worth because 3D core model can more exactly consider the shape of the control rod. Furthermore it was judged that the result of the analysis on the sodium void reactivity .....

JAEA Reports

Evaluation for the transient Burst property of austenitic steel fuel Claddings irradiated as the MONJU type Fuel Assemblies (MFA-1&MFA-2)in FFTF

; ; Sakamoto, Naoki; *; Akasaka, Naoaki;

JNC TN9400 2000-095, 110 Pages, 2000/07

JNC-TN9400-2000-095.pdf:13.57MB

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 $^{27}$ n/m $^{2}$ . 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 1055.6 $^{circ}$ C. This suggested that the design cladding maximum temperature limit for MONJU (830 $^{circ}$ C) was conservative. (4)There was no obvious relation between rupture temperature, swelling and microstructural change during transient heating under the irradiation conditions examined.