Miyahara, Shinya*; Arita, Yuji*; Nakano, Keita; Maekawa, Fujio; Sasa, Toshinobu; Obayashi, Hironari; Takei, Hayanori
Nuclear Engineering and Design, 403, p.112147_1 - 112147_17, 2023/03
It is important to evaluate the inventories and the release and transport behavior of the spallation products (SPs) in the Lead-Bismuth Eutectic (LBE) coolant system of Accelerator Driven System (ADS) for the safety studies of the radiological hazard both in the cases of normal operation and accident. University of Fukui and JAEA have been developing the computer analysis code TRAIL (Transport of RAdionuclides In Liquid metal systems) which predicts the time dependent behavior of SPs within the LBE coolant system of ADS for the wide range of operational events. The source term of both radioactive and stable SPs in the LBE coolant is given as input and the radioactive decay chain model for the radioactive SPs is implemented in the code to evaluate the effect of precursors on the SPs mobility. This paper presents the recent advancement status of the code development and the validation results comparing with the distribution data of volatile SPs in MEGAPIE spallation target.
Saito, Shigeru; Suzuki, Kazuhiro; Hatakeyama, Yuichi; Suzuki, Miho; Dai, Y.*
Journal of Nuclear Materials, 534, p.152146_1 - 152146_16, 2020/06
A post-irradiation examination (PIE) was performed on the tensile specimens prepared from the MEGAPIE (MEGAwatt Pilot Experiment) target which were irradiated in flowing lead-bismuth eutectic (LBE). Thicknesses of the specimens were over two times larger than that of the standard specimen. The PIE revealed that the T91 specimens showed a 1.5-2.0 times larger total elongation (TE) compared to the literature values for a specimen with standard t/w (ratio of thickness to width). It could be suggested that the t/w and TE were strongly correlated. Then, we tried to investigate the effects of the t/w on the TE by comparing unirradiated specimens. We found that there was no t/w dependence on the strength and uniform elongation. On the other hand, the TE increases with increasing t/w. Based on the experimental data, we correlated the TE with various specimens t/w to estimate appropriate TE values, including that for the standard specimen.
Kurata, Yuji; Kikuchi, Kenji; Saito, Shigeru; Futakawa, Masatoshi; Sasa, Toshinobu
FZKA-6876, p.190 - 198, 2003/12
A report at MEGAPIE(Megawatt Pilot Experiment) Technical R & D Meeting is collected into an FZK report. According to the static corrosion tests, Al surface-treated layer produced by the gas diffusion method exhabited corrosion resistance to liquid Pb-Bi, while Al surface-treated layer produced by the melt dipping method suffered a severe corrosion attack. Furtheremore, it was found that a thick ferrite layer was formed in the surface of austenitic stainless steel at 550C. Dissolution at high temperature parts, precipitation of Fe-Cr alloy and deposition of PbO at low temperature parts occured in the first loop corrosion test. These caused plugging of the narrow passage in electro-magnetic pumu(EMP) system. Adoption of filters and a wide passage in an EMP system, and the use of an inner-polished tube specimen brought about a good effect.
Futakawa, Masatoshi; Kurata, Yuji; Henry, J.*; Ioka, Ikuo; Saito, Shigeru; Naito, Akira
FZKA-6876, p.166 - 171, 2003/12
A report at MEGAPIE(Megawatt Pilot Experiment) Technical R & D Meeting is collected into an FZK report. Triple ion beam irradiation tests on T91 specimens were conducted under MEGAPIE condition using TIARA facility at JAERI. Results of triple ion beam irradiation up to 15dpa, 1400appm He, 10000appm H at 320C were compared with those of single or dual beam irradiation of Fe or He ions by use of a micro-indentation method. Hardsness increase was mainly attributed to displacement damage by Fe ions. A little effect on hardness was found on simultaneous implantation of He and H ions. An analysis method to predict mechanical characterization form micro-indentation test results was developed on ion irradiated materials.
Saito, Shigeru; Kikuchi, Kenji*; Suzuki, Kazuhiro; Hatakeyama, Yuichi; Endo, Shinya; Suzuki, Miho; Okubo, Nariaki; Kondo, Keietsu
no journal, ,
The world's first megawatt-class lead-bismuth target, MEGAPIE (MEGAwatt Pilot Experiment), was dismantled and post irradiation examination (PIE) samples were prepared at PSI hot-lab. The samples were shipped to each institutions including JAEA. The samples were cut from the beam window (BW, T91) and the flow guide tube (FGT, SS316L). And all samples are prepared without LBE. The irradiation conditions of the specimens irradiated at SINQ target were as follows: proton energy was 580 MeV, irradiation temperatures were ranged from 251 to 341C, and displacement damage levels were ranged from 0.16 to 1.57 dpa. PIE including SP (small punch) and three point bending tests were performed. SP tests were executed for T91 and SS316L specimens at R.T. in air condition. Specimen size for SP test with 2.4 mm steel-ball is 8 mm 8 mm 0.5 mm. T91 specimens were cut from the Spitze (triangle) sample and polished to thickness of 0.5 mm. The OM/SP specimens of SS316L were polished to thickness of 0.5 mm. Three point bending tests were executed for SS316L specimens at R.T. in air condition. The bend bar specimens of SS316L without notch were employed. Results of the SP tests and three point bending tests on the irradiated specimens will be presented at the workshop. Cross sectional observation on the Spitze sample and microstructural observation by TEM will be also reported.
Saito, Shigeru; Okubo, Nariaki; Endo, Shinya; Suzuki, Kazuhiro; Hatakeyama, Yuichi; Kikuchi, Kenji*
no journal, ,
To evaluate the lifetime of the beam window of an accelerator-driven transmutation system (ADS) and spallation neutron source, material irradiation programs, the STIP (SINQ target irradiation program, SINQ; Swiss spallation neutron source) and MEGAPIE (MEGAwatt Pilot Experiment), have been executed. Part of the specimens were transported to JAEA and post irradiation examination (PIE) of the specimens was carried out. In this presentation, in addition to representative results of the PIE, our experience and knowledge of irradiation experiments and PIE processes will be introduced. These information will be useful for high energy particle irradiation experiments and PIE planed under the frame work of RaDIATE.
Maekawa, Fujio; Nakano, Keita; Sasa, Toshinobu; Obayashi, Hironari; Takei, Hayanori; Miyahara, Shinya*; Arita, Yuji*
no journal, ,
In the MEGAPIE experiment conducted at the Paul Scherrer Institut in Switzerland in which a lead-bismuth eutectic (LBE) alloy spallation target was irradiated by a 575-MeV proton beam, the amount of spallation products (SP) in LBE was evaluated by the PHITS code.
Miyahara, Shinya*; Arita, Yuji*; Maekawa, Fujio; Nakano, Keita; Sasa, Toshinobu; Obayashi, Hironari; Takei, Hayanori
no journal, ,
To validate the TRAIL code, the radioactivity of noble gas (Ar, Kr, Xe), mercury (Hg) and gold (Au) measured in the cover gas of the MEGAPIE target at the start-up of the operation has been evaluated using the code. The release behavior of these spallation products from LBE was discussed based on the results from the viewpoint of the solubility in LBE and the vapor pressure.
Saito, Shigeru; Wakui, Takashi; Tsukada, Manabu*; Yamashita, Naoki; Sano, Naruto; Dai, Y.*; Futakawa, Masatoshi
no journal, ,
Post irradiation examination (PIE) of the MEGAPIE (MEGAwatt Pilot Experiment) project has been performed on the samples allotted to JAEA. In the experiments, specimens for tensile test are prepared by taking from the component of the MEGAPIE target such as the beam window (BW) of T91. The irradiation temperatures were about 250 C and the displacement-damage levels ranged between 0.75 and 1.74 dpa. After the tensile tests, SP specimens are prepared from the grip part of the tested tensile specimens. Testing temperatures for SP tests ranged from -150C to 250C. From the area of the load-displacement curves (LDC) of the SP tests, ductile-brittle transition temperature (DBTT) was evaluated. Comparison of these data with previous STIP data showed similar values. In addition, the yield stress and ultimate tensile strength were calculated from the SP tests results by applying the conversion equation. These were compared with the results of the tensile tests and found to be in good agreement.