Study on creep damage assessment method for Mod.9Cr-1Mo steel by sampling creep testing with thin plate specimen

Kanayama, Hideyuki*; Hiyoshi, Noritake*; Ogawa, Fumio*; Kawabata, Mie*; Ito, Takamoto*; Wakai, Takashi

Zairyo, 68(5), p.421 - 428, 2019/05

This study presents creep damage assessment method for Mod. 9Cr-1Mo steel by sampling creep testing with thin plate specimen. Tensile creep rupture tests were performed using three different sizes of specimen under two different test environments to verify the creep testing with the thin plate specimen. Time to rupture of Mod. 9Cr-1Mo steel using three different sizes were almost same. In addition, there was no effect of environment on time to rupture. Pre-damaged thin plate specimens were machined from a bulk specimen's gage section that pre-damage test was performed with. Pre-damage based on life fraction rule were 8%, 16% and 25%. No effect of the process of machining pre-damaged specimen on time to rupture was confirmed by verification tests in same test condition as pre-damage test. Stress acceleration creep rupture tests were performed to estimate creep damage assessment. Creep damage assessment by stress acceleration creep rupture tests was sufficiently accurate estimate. Creep damage assessments by Vickers hardness and lath width were compared with the assessment by stress acceleration creep rupture tests to study applicability of these methods.

Clinical significance of L-type amino acid transporter 1 expression as a prognostic marker and potential of new targeting therapy in biliary tract cancer

Kaira, Kyoichi*; Sunose, Yutaka*; Ohshima, Yasuhiro; Ishioka, Noriko; Arakawa, Kazuhisa*; Ogawa, Tetsushi*; Sunaga, Noriaki*; Shimizu, Kimihiro*; Tominaga, Hideyuki*; Oriuchi, Noboru*; et al.

BMC Cancer, 13, p.482_1 - 482_12, 2013/10

https://doi.org/10.1186/1471-2407-13-482

Assessment system of marine environment in the Japan Sea

Kawamura, Hideyuki; Kobayashi, Takuya; Togawa, Orihiko; Onitsuka, Go*

Proceedings of 7th International Conference on Natural Computation (ICNC '11)/8th International Conference on Fuzzy Systems and Knowledge Discovery (FSKD '11), p.1742 - 1746, 2011/07

An assessment system of marine environment in the Japan Sea is developed in Japan Atomic Energy Agency to calculate a movement of pollutants such as radionuclides and their effect on Japanese people. The assessment system consists of three models, ocean general circulation model, particle random-walk model, and dose assessment model. The assessment system was applied so far to a numerical experiment of an oil spill accident and a numerical experiment for reproduction of concentration of anthropogenic radionuclides in the Japan Sea. In addition, the lower trophic level ecosystem model is being developed to estimate a suspended solid in the Japan Sea.

Simulation of concentrations of anthropogenic radionuclides in the Japan Sea

Kawamura, Hideyuki; Ito, Toshimichi; Kobayashi, Takuya; Otosaka, Shigeyoshi; Hirose, Naoki*; Togawa, Orihiko

Proceedings of Joint International Conference of 7th Supercomputing in Nuclear Application and 3rd Monte Carlo (SNA + MC 2010) (USB Flash Drive), 4 Pages, 2010/10

This study aims to demonstrate many findings in the Japan Sea expeditions by Japan Atomic Energy Agency between 1997 and 2002 making use of an ocean general circulation model. A numerical experiment is performed between 1945 and 2000 with deposition at the sea surface by global fallout as main source of anthropogenic radionuclides. The concentrations of Sr and Cs in the surface layer are approximately in the range of 1.0-1.5 Bq/m and 2.0-2.5 Bq/m and they exponentially decrease with depth from the sea surface to the sea bottom. Total amounts of Sr and Cs in the seawater of the Japan Sea are estimated to be about 1.34 PBq (1 PBq = 10 Bq) and 2.02 PBq in the numerical experiment, which demonstrates observational estimations in the Japan Sea expeditions. Time series of the total amounts show that they attain the maximums of 4.86 PBq for Sr and 7.33 PBq for Cs in 1964.

Improvement of the marine radionuclides prediction code in the off Shimokita Region

Kobayashi, Takuya; Togawa, Orihiko; Ito, Toshimichi; Otosaka, Shigeyoshi; Kawamura, Hideyuki; Hayashi, Keisuke*; Shima, Shigeki*; Nakayama, Tomoharu*; In, Teiji*

JAEA-Research 2009-040, 63 Pages, 2009/12

JAEA-Research-2009-040.pdf:12.19MB

A spent nuclear fuel reprocessing plant has the possibility of routine releases of liquid radioactive wastes from a discharge pipe to the off Shimokita region during its operations. Thus, for environmental safety, it is important to assess the migration processes of released radionuclides from the plant. Therefore, an ocean circulation prediction code and an oceanic radionuclides migration prediction code, which were developed by Japan Atomic Energy Agency, has been improved to describe the migration behavior of radionuclides in the off Shimokita region. Parameters on characteristics and dynamics of particulate materials in seawater have also been obtained in the study area for the adjustment and verification of the oceanic radionuclides migration prediction code. This report summarizes the primary results of the study which was carried out at the off Shimokita region from FY2003 to 2008.

Development of a system for the prediction of radionuclide migration in the off Shimokita region and its case study

Kobayashi, Takuya; In, Teiji*; Ishikawa, Yoichi*; Matsuura, Yasutaka*; Shima, Shigeki*; Nakayama, Tomoharu*; Awaji, Toshiyuki*; Kawamura, Hideyuki; Togawa, Orihiko

Nihon Genshiryoku Gakkai Wabun Rombunshi, 7(2), p.112 - 126, 2008/06

https://doi.org/10.3327/taesj.J07.025

The radionuclides migration forecasting system in the off Shimokita region has been developed to predict the routine and accidental releases of liquid radioactive wastes during the operations of a spent nuclear fuel reprocessing plant in Aomori prefecture, Japan. The results obtained from the case studies are as follows; (1) The ocean general circulation model by using the techniques of data assimilation and nesting reproduced well the flow pattern of a coastal area. (2) The estimated internal dose due to ingestion of marine products from hypothetical release of H was 0.45 Sv/y. (3) The results of hypothetical release of Cs showed that about four percent of the whole deposited on the seabed after a 60-day calculation. The concentration of Cs of hypothetical release from the off Shimokita region is the same or less than that of global fallout measured at the same area.

The Oceanic forecasting system near the Shimokita Peninsula, Japan

In, Teiji*; Nakayama, Tomoharu*; Matsuura, Yasutaka*; Shima, Shigeki*; Ishikawa, Yoichi*; Awaji, Toshiyuki*; Kobayashi, Takuya; Kawamura, Hideyuki; Togawa, Orihiko; Toyoda, Takahiro*

Proceedings of International Symposium on Environmental Modeling and Radioecology, p.58 - 64, 2007/03

The northwestern part of the Pacific Ocean off the Shimokita Peninsula assumes a complex water mass structure. It is necessary to accurately reproduce the striking circulation patterns and the complicated water mass structures in this area with an ocean general circulation model. We have planned to make use of a one-way nesting method. To initialize the forecast system, we use a 4-dimensional variational method of data assimilation. The assimilated data consist of hydrographic observations collected through the Global Temperature-Salinity Profile Program, sea surface temperature and sea surface height data observed by satellites. A forecast experiment on the basis of oceanographic observations made in 2003 illustrates the good performance of our system. We shall focus, in particular, on the shift from the coastal mode to the gyre mode and vice versa.

Study on reactor core and fuel design of sodium-cooled fast reactor (Metal fuel core); Results in JFY 2005

Oki, Shigeo; Sugino, Kazuteru; Ogawa, Takashi; Aida, Tatsuya*; Hayashi, Hideyuki

JAEA-Research 2006-077, 86 Pages, 2006/11

JAEA-Research-2006-077.pdf:6.34MB

Core and fuel design study of was performed. The reference specification of the large-scale (1,500 MWe) and the middle-scale (750 MWe) cores were proposed as a final result of . Since the local conversion ratio of any of the core points is made close to unity with single Pu enrichment, it is possible to minimize the necessary coolant flow rate for the core region and then, accept high reactor outlet temperature of 550C. By the rationalization of hot spot factors, the coolant flow distribution design can be optimized to 5 regions for the large-scale core and 8 regions for the middle-scale core, respectively. It was also confirmed that the core specification met the criteria of fuel-assembly integrity, as well as those of shielding design. For further improvement on the reactor outlet temperature condition, the reduction of the maximum cladding inner-wall temperature was investigated with the reflection of the actual control rod insertion depth and the rationalization of the excess-reactivity uncertainty. An alternative core design was investigated by adopting the PNC-FMS steel as the cladding material instead of the ODS steel. As a result of the investigation of extending the control rod lifetime, three-cycle lifetime (which is the same as fuel assemblies) could be possible by means of the reductions in B enrichment and BC pellet diameter.

Operation and management of STACY experiment using Pseudo-FPs-doped fuel

Izawa, Kazuhiko; Seki, Masakazu; Hirose, Hideyuki; Kaminaga, Jota; Aoyama, Yasuo; Yoshida, Hiroshi; Sono, Hiroki; Ogawa, Kazuhiko; Sakuraba, Koichi

UTNL-R-0453, p.9_1 - 9_10, 2006/03

no abstracts in English

Oil spill simulation in the Japan Sea

Kawamura, Hideyuki; Kobayashi, Takuya; Hirose, Naoki*; Ito, Toshimichi; Togawa, Orihiko

WIT Transactions on Ecology and the Environment, Vol.88, p.273 - 278, 2006/00

An assessment system of marine environment in the Japan Sea is being constructed in the Japan Atomic Energy Agency. It is composed of an ocean general circulation model (RIAMOM), a particle random-walk model (SEA-GEARN) and a radiation dose assessment model (COLDOS). This study aims to confirm a validity of the assessment system by reproducing a movement of spilled oil at an incident of Russian tanker Nakhodka, in January 1997. Realistic reproduction of ocean conditions is a significant factor for accurate simulations of the movement of spilled oil. In this study, one of data assimilation techniques, an approximate Kalman filter, was introduced by combining RIAMOM with sea level measurements of satellite data. The assimilated results were in good agreement with observed oceanic phenomena both qualitatively and quantitatively. Using the calculated ocean currents, simulations of behaviour of spilled oil was performed with SEA-GEARN. The tanker was ruptured in a storm about 100 km north of the Oki Islands in Shimane Prefecture, Japan, on January 2, 1997. Most of oil spread over off Hyogo, Kyoto, Fukui and Ishikawa Prefecture, meanwhile a part of it reached a coast of Niigata Prefecture detouring around Noto Peninsula by January 21, 1997. The most important feature in these regions is considered to be a branch of the Tsushima Warm Current (TWC). Owing to a variability of TWC, ocean eddy activities and a sea surface wind, the spilled oil dispersed widely in space. On the other hand, the strong northeastward component of TWC was likely to drive the spilled oil to Niigata Prefecture. A number of experiments with different parameters and situations showed that the assimilated daily ocean currents with wind drift gave the best effect on simulation for the movement of spilled oil.