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Journal Articles

Integration of transportation simulation with a level 3 PRA code for nuclear power plants

Shimada, Kazumasa; Sakurahara, Tatsuya*; Reihani, S.*; Mohagehgh, Z.*

Proceedings of Asian Symposium on Risk Assessment and Management 2020 (ASRAM 2020) (Internet), 12 Pages, 2020/11

Level 3 Probabilistic Risk Assessment (Level 3 PRA) and Traffic simulation were integrated to evaluate the effects of evacuation more realistically on radiation exposure to residents in the offsite consequence analysis. In this study, WinMACCS was used as the Level 3 PRA code. As a test case, the Sequoyah Nuclear Power Plant(NPP) site, which was targeted by the State-of-the-Art Reactor Consequence Analyzes (SOARCA) issued by U.S. Nuclear Regulatory Commission in 2017, was adopted. The MultiAgent Transport Simulation (MATSim) was used to simulate the evacuation of a Sequoyah NPP's 10-mile Emergency Planning Zone. For the transportation route choice, the route where each vehicle chooses the shortest distance and the route where the total evacuation time is shortened by iterative calculation were chosen. In the calculation of MACCS, the source term with the shortest release start time in the SOARCA report was adopted. As an example of the results, the radiation dose of the residents when the evacuation time was optimized was reduced by about 30% from the dose when the shortest distance was selected. Furthermore, a sensitivity analysis was conducted, and it was shown that the evacuation preparation time was the largest factor that contributed to the radiation dose to residents.

JAEA Reports

Basis for handling of nuclear fuel materials (Second edition)

Task Force on Writing Textbook of Nuclear Fuel Materials

JAEA-Review 2020-007, 165 Pages, 2020/07

JAEA-Review-2020-007.pdf:6.63MB

The present textbook was written by Task Force on Writing Textbook of Nuclear Fuel Materials at the Nuclear Science Research Institute in order to improve technological abilities of engineers and researchers who handle nuclear fuel materials. The taskforce consists of young and middle class engineers each having certification for chief engineer of nuclear fuel. The present textbook mainly deals with uranium and plutonium, and shows their nuclear properties, physical and chemical properties, and radiation effects on materials and human body. It also presents basic matters for safety handling of nuclear fuel materials, such as handling of nuclear fuel materials with hood and glovebox, important points in storage and transportation of nuclear fuel materials, radioactive waste management, radiation safety management, and emergency management. Furthermore, incident cases at domestic and foreign nuclear fuel materials facilities are compiled to learn from the past.

Journal Articles

Improvement of neutron startup source handling work by developing new transportation container for High-Temperature engineering Test Reactor (HTTR)

Shimazaki, Yosuke; Sawahata, Hiroaki; Shinohara, Masanori; Yanagida, Yoshinori; Kawamoto, Taiki; Takada, Shoji

Journal of Nuclear Science and Technology, 54(2), p.260 - 266, 2017/02

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

The High-Temperature engineering Test Reactor (HTTR) has three neutron startup sources (NSs) in the reactor core, each of which consists of $$^{252}$$Cf with 3.7 GBq and is contained in a small capsule, installed in NS holder and subsequently in a control guide block (CR block). The NSs are exchanged at the interval of approximately 7 years. The NS holders are transported from the dealer's hot cell to the reactor facility of HTTR using a transportation container. The loading work of NS holders to the CR blocks is subsequently carried out in the fuel handling machine maintenance pit of HTTR. Technical issues, which are the reduction and prevention of radiation exposure of workers and the exclusion of falling of NS holder, were extracted from the experiences in past two exchange works of NSs to develop a safety handling procedure. Then, a new transportation container special to the NSs of HTTR was developed to solve the technical issues while keeping the cost as low as that for overhaul of conventional container. As the results, the NS handling work using the new transportation container was safely accomplished by developing the new transportation container which can reduce the risks of radiation exposure dose of workers and exclude the falling of NS holder.

JAEA Reports

Shielding calculation by PHITS code during replacement works of startup neutron sources for HTTR operation

Shinohara, Masanori; Ishitsuka, Etsuo; Shimazaki, Yosuke; Sawahata, Hiroaki

JAEA-Technology 2016-033, 65 Pages, 2017/01

JAEA-Technology-2016-033.pdf:11.14MB

To reduce the neutron exposure dose for workers during the replacement works of the startup neutron sources of the High Temperature Engineering Test Reactor, calculations of the exposure dose in case of temporary neutron shielding at the bottom of fuels handling machine were carried out by the PHITS code. As a result, it is clear that the dose equivalent rate due to neutron radiation can be reduced to about an order of magnitude by setting a temporary neutron shielding at the bottom of shielding cask for the fuel handling machine. In the actual replacement works, by setting temporary neutron shielding, it was achieved that the cumulative equivalent dose of the workers was reduced to 0.3 man mSv which is less than half of cumulative equivalent dose for the previous replacement works; 0.7 man mSv.

Journal Articles

Calculations of safe distance from the point of a severe accident during transportation of a package containing spent nuclear fuels

Watanabe, Fumitaka; Okuno, Hiroshi

Proceedings of 18th International Symposium on the Packaging and Transport of Radioactive Materials (PATRAM 2016) (DVD-ROM), 9 Pages, 2016/09

This paper shows our calculations on the effects of a radiological release by assuming a severe accident in nuclear material transportation. Following recalculations of safe distance from the point of a severe accident during transportation of a transportation cask TN12 typically used in France containing spent nuclear fuel, and calculations to replicate the "Regulatory Guide: Emergency Preparedness for Nuclear Facilities", a similar calculation was made for a spent fuel transportation cask NFT-14P that was typically utilized in Japan instead of TN12. The safe distance was calculated to be about 30 m. The above calculations were made with the HotSpot codes which adopted the Gauss plume model and had been developed by the USA. Some additional calculations were made with EyesAct, which was developed and used in Japan, adopting also the Gauss plume model, to compare calculation results.

Journal Articles

Development of transportation container for the neutron startup source of High Temperature engineering Test Reactor (HTTR)

Shimazaki, Yosuke; Ono, Masato; Tochio, Daisuke; Takada, Shoji; Sawahata, Hiroaki; Kawamoto, Taiki; Hamamoto, Shimpei; Shinohara, Masanori

Proceedings of International Topical Meeting on Research Reactor Fuel Management and Meeting of the International Group on Reactor Research (RRFM/IGORR 2016) (Internet), p.1034 - 1042, 2016/03

In High Temperature Engineering Test Reactor (HTTR), three neutron holders containing $$^{252}$$Cf with 3.7 GBq for each are loaded in the graphite blocks and inserted into the reactor core as a neutron startup source which is changed at the interval of approximately ten years. These neutron holders containing the neutron sources are transported from the dealer's hot cell to HTTR using the transportation container. The holders loading to the graphite block are carried out in the fuel handling machine maintenance pit of HTTR. There were two technical issues for the safety handling work of the neutron holder. The one is the radiation exposure caused by significant movement of the container due to an earthquake, because the conventional transportation container was so large ($$phi$$1240 mm, h1855 mm) that it can not be fixed on the top floor of maintenance pit by bolts. The other is the falling of the neutron holder caused by the difficult remote handling work, because the neutron holder capsule was also so long ($$phi$$155 mm, h1285 mm) that it can not be pulled into the adequate working space in the maintenance pit. Therefore, a new and low cost transportation container, which can solve the issues, was developed. To avoid the neutron and $$gamma$$ ray exposure, smaller transportation container ($$phi$$820mm, h1150 mm) which can be fixed on the top floor of maintenance pit by bolts was developed. In addition, to avoid the falling of the neutron holder, smaller neutron holder capsule ($$phi$$75 mm, h135 mm) with simple handling mechanism which can be treated easily by manipulator was also developed. As the result of development, the neutron holder handling work was safely accomplished. Moreover, a cost reduction for manufacturing was also achieved by simplifying the mechanism of neutron holder capsule and downsizing.

JAEA Reports

Treatment and decomposition of HLW-79Y-4T type transportation cask for liquid radioactive fuel material

Yamaguchi, Isoo*; Morita, Yasuji; Fujiwara, Takeshi; Yamagishi, Isao

JAERI-Tech 2005-054, 61 Pages, 2005/09

JAERI-Tech-2005-054.pdf:12.38MB

The HLW-79Y-4T type transportation cask for liquid radioactive fuel material (commonly called "Cendrillon") was imported from France and modified for Japanese regulation in order to obtain high-level radioactive liquid waste (HLW) for partitioning tests in JAERI by transportation from Tokai Establishment of Japan Nuclear Fuel Cycle Development Institute. The cask was used for the HLW transportation five times from 1982 to 1990. After that, it was kept and maintained for next transportation of HLW from facilities outside JAERI. Finally, we decided to decompose the cask because HLW can be obtained in JAERI Tokai. For the decomposition, radiation dose and contamination by radioactivity was first measured and then the methods to reduce those levels were determined. The cask was decomposed after the decontamination to separate the part that has high radiation level. The separated part was put in a vessel specially prepared. The present report describes those procedures for the decomposition of the transportation cask.

JAEA Reports

An Investigation on energy consumption trend in Japan; Transportation sector

Suzuki, Takayoshi*

JAERI-Review 2005-030, 37 Pages, 2005/08

JAERI-Review-2005-030.pdf:2.28MB

Although energy consumption in the industry sector has almost been stable, energy consumption in the transportation (passenger and freight) sector has increased after the oil crisis. The increase of energy consumption in passenger sector can be attributed to the increase in transportation by private passenger vehicles; while the increase in freight sector was due to the modal shift to trucks. Among transportation methods, automobiles are now dominant in terms of energy consumption and also in terms of amount of transportation. Therefore implementing energy conservation measures relating to automobiles is very important in order to suppress the energy consumption in transportation. This report summarizes the results of investigation on energy conservation measures, especially relevant to automobiles. The investigation has shown that most promising and effective technologies or measures are promoting market penetration of vehicles satisfying "top runner standard", development and employment of hybrid vehicles, and introduction of vehicles with "idling-stop" systems.

JAEA Reports

Evaluation of hydrogen cost

Nishihara, Tetsuo; Takeda, Tetsuaki

JAERI-Tech 2005-038, 40 Pages, 2005/07

JAERI-Tech-2005-038.pdf:5.01MB

R&D of the IS process technology and the integration technology of a high-temperature gas reactor and a heat utilization system is advanced by Japan Atomic Energy Research Institute. Hydrogen suuply system to fuel cell cars consists of off-site system and on-site system. The cost evaluation of on-site system must include the cost of storage, transportation, and refueling as well as that of production. Moreover, the hydrogen produced with the fossil fuel must consider the cost of carbon dioxide disposal. The cost evaluation data related to storage, transportaion and refueling in Japan and the USA are investigated. The cost evaluation of several off-site and on-siste systems are carried out.

JAEA Reports

On the requirement for remodelling the spent nuclear fuel transportation casks for research reactors; A Review of the drop impact analyses of JRC-80Y-20T

Review Group on the Structure of the Spent Nuclear Fuel Transportation Casks for

JAERI-Review 2005-023, 133 Pages, 2005/07

JAERI-Review-2005-023.pdf:18.88MB

The Japan Atomic Energy Research Institute (JAERI) constructed two stainless steel transportation casks, JRC-80Y-20T, for spent nuclear fuels of research reactors and had utilized them for transportation since 1981. A modification of the design was applied to the USA for transportation of silicide fuels. Additional analyses employing the impact analysis code LS-DYNA that was often used for safety analysis were submitted by the JAERI to the USA to show integrity of the packages; the casks were still not approved, because inelastic deformation was occurred on the surface of the lid touching to the body. To resolve this problem on design approval of transportation casks, a review group was formed at the end of this June. The group examined the impact analyses by reviewing the input data and performing the sensitivity analyses. As the drop impact analyses were found to be practically reasonable, it was concluded that the approval of the USA for the transportation casks could not be obtained just by revising the analyses; therefore, remodelling the casks is required.

JAEA Reports

Transportation of significant metals recovered in real sea experiment of adsorbents

Takeda, Hayato*; Onuma, Kenji*; Tamada, Masao; Kasai, Noboru; Katakai, Akio; Hasegawa, Shin; Seko, Noriaki; Kawabata, Yukiya*; Sugo, Takanobu

JAERI-Tech 2001-062, 66 Pages, 2001/10

JAERI-Tech-2001-062.pdf:5.5MB

Real sea experiment for the recovery of significant metals such as uranium and vanadium has been carried out at the offing of Mutsu establishment to evaluate the adsorption performance of adsorbent synthesized by radiation-induced graft-polymerization. After elution of uranium and vanadium from the adsorbent, their metals were adsorbed onto the conventional chelate resin. This chelate resin in a plastic column was further put in a cylindrical stainless transport container. The container was transported to the facility for separation and purification by a truck for the exclusive loading. The maximum concentration is 60 Bq/g when the uranium is adsorbed on the chelate resin. Transportation of recovered metals can be treated as general substance since these amount and concentration are out of legal control. However, the recovered metals were transported in conformity to L type transportation as a voluntary regulation. The strength analysis of the container was equal to the safety level of IP-2 type which is higher transportation grade than L type .

Journal Articles

A Method to calculate sensitivity coefficients of reactivity to errors in estimating amounts of nuclides found in irradiated fuel

; Suyama, Kenya; *

Journal of Nuclear Science and Technology, 35(3), p.240 - 242, 1998/03

 Times Cited Count:1 Percentile:15.58(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Criticality safety studies related to advisory material for the IAEA regulations

; *

Proc. of PATRAM'98, 1, p.217 - 223, 1998/00

no abstracts in English

JAEA Reports

AVS user's guide on the basis of practice

*; Kato, Katsumi*; Kume, Etsuo;

JAERI-Tech 97-028, 37 Pages, 1997/07

JAERI-Tech-97-028.pdf:1.32MB

no abstracts in English

Journal Articles

Computer code system for structural analysis of radioactive materials transport

; *; *

PATRAM 95: 11th Int. Conf. on the Packaging and Transportation of Radioactive Materials, 3, p.1174 - 1181, 1996/00

no abstracts in English

Journal Articles

Feasibility study on a nuclear floating island(NUFIS)

; *; ; *

Nihon Genshiryoku Gakkai-Shi, 23(2), p.34 - 42, 1981/00

no abstracts in English

16 (Records 1-16 displayed on this page)
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