著者
松村 宏 斎藤 究 石岡 純 上蓑 義朋
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 (ISSN:13472879)
巻号頁・発行日
vol.10, no.3, pp.152-162, 2011 (Released:2011-07-29)
参考文献数
3
被引用文献数
15 10

In Fukushima and neighboring prefectures, the distributions of dose rate and γ-ray count rate of radionuclides from the Fukushima Daiichi Nuclear Power Station were measured on expressways on March 15, 16, 17, and April 8, 2011, using an NaI(Tl) detector and a LaBr3 detector. A radioactive plume that contained 133Xe, 132Te, 132I, 131I, 134Cs, and 136Cs was observed at Koriyama on the afternoon of March 15. The plume arrived in the Nakadori region of Fukushima prefecture, which is surrounded by two mountain ranges, and most of the radioactivity there was deposited by rainfall. Although the distributions of 132Te, 132I, 134Cs, 136Cs, and 137Cs were similar, the distribution of 131I was different from the others. The effective nuclides for the dose rate measurement were 132Te and 132I on March 15-17 and 134Cs and 137Cs on April 8. The initial distribution profile of the dose rate on March 15-17 was retained on April 8 because the deposited radioactive material was not moved from the initial location and there was no additional effective deposition of radioactivity.
著者
長縄 弘親 熊沢 紀之 斉藤 浩 柳瀬 信之 三田村 久吉 永野 哲志 鹿嶋 薫 福田 達也 吉田 善行 田中 俊一
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 (ISSN:13472879)
巻号頁・発行日
pp.1109220007-1109220007, (Released:2011-09-27)
参考文献数
7
被引用文献数
3 2

We tried the decontamination of surface soils for three types of agricultural land at Nagadoro district of Iitate-mura (village) in Fukushima Prefecture, which is highly contaminated by deposits of radionuclides from the plume released from the Fukushima Daiichi nuclear power plant. The decontamination method consisted of the peeling of surface soils solidified using a polyion complex, which was formed from a salt solution of polycations and polyanions. Two types of polyion complex solution were applied to an upland field in a plastic greenhouse, a pasture, and a paddy field. The decontamination efficiency of the surface soils reached 90%, and dust release was effectively suppressed during the removal of surface soils.
著者
菅原 慎悦 城山 英明
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 = Transactions of the Atomic Energy Society of Japan (ISSN:13472879)
巻号頁・発行日
vol.9, no.4, pp.368-383, 2010-12-01
被引用文献数
1 2

In France, there exist organizations called "Commission Locale d'Information" (CLI) in all the siting areas where nuclear facilities located. Previously, the CLI organizations were established voluntarily by some local governments or nuclear utilities. Since 2006, however, the Nuclear Transparency and Safety Act has obliged the establishment of CLI in all the siting areas in conjunction with reforming the nuclear regulatory agencies. This means that the concerned local governments are officially part of nuclear safety regulation. In this study, we investigated present conditions of the CLI organizations through some interviews in France and consider their roles from the standpoint of nuclear regulatory governance. As a result, we found that the CLI plays the following roles: (1) medium of communication among concerned parties (not only between nuclear utilities and local habitants but also between the national nuclear regulatory agency and various local governments) and (2) implementing various activities in accordance with each local condition through the participation of local assembly members. In addition, we clarified that CLI's activities are supported by related institutional infrastructures, such as cost burden between central and local governments, and some other systems of citizen participation in building or expanding nuclear facilities.<br>
著者
加藤 和明
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.23, no.2, pp.111-115, 1981

An accidental loss of an RI radiation source, a sealed <SUP>90</SUP>Sr of 1mCi, which occurred at KEK in March, 1980, is reported. Actual dealing with it and lessons learned from it are also stated. In addition, problems in radiation control works at a public research laboratory for universities such as KEK are discussed.
著者
中田 翔治 高嶋 隆太 長野 浩司 木村 浩 班目 春樹
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 = Transactions of the Atomic Energy Society of Japan (ISSN:13472879)
巻号頁・発行日
vol.9, no.3, pp.252-270, 2010-09-01
被引用文献数
1

Replacement of nuclear power plants has the possibility of affecting the management of electric power suppliers. Therefore, in the nuclear policy, a depreciation method as an equalization method, which means that part of the investment cost is accumulated as an allowance, and after the start of operation, the depreciation cost in the replacement project is equalized, has been introduced in Japan. In this paper, we evaluate the replacement of nuclear power plants by taking into account the uncertainty of operating costs and the depreciation cost in order to examine the effect of the depreciation method on the decision criteria of the replacement. We found that the equalization method is effective for inducing the acceleration of the replacement. Furthermore, we show the relationship between the uncertainty and the depreciation method. It turns out that as uncertainty increases, the difference in investment threshold between the equalization method and the existing depreciation method decreases, and that in option value increases.<br>
著者
沢 和弘 植田 祥平 相原 純 湊 和生 小川 徹
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 (ISSN:13472879)
巻号頁・発行日
vol.6, no.2, pp.113-125, 2007 (Released:2012-03-07)
参考文献数
55

Interest in the future hydrogen economy has prompted the research and development of the Very High-Temperature Gas-Cooled Reactor (VHTR). To achieve the targeted outlet gas temperature exceeding 950°C, material problems have yet to be solved. The development of advanced coated particle fuel is also due in view of the vulnerability of the SiC layer of conventional TRISO-coated particle fuel at temperatures exceeding 1,600°C. The coated particle fuel employing ZrC instead of SiC has been developed in JAEA. Although the past irradiation tests on the ZrC-coated particle fuel were exclusively on samples from the laboratory scale production, the promising results have been obtained. The properties, fabrication and inspection techniques as well as the results of irradiation and post-irradiation tests are reviewed. The post-irradiation heating tests at accident temperatures above 1,600°C revealed the durability of the ZrC-layer, which maintained the tightness to noble-gas and volatile metal fission products. From 2004, JAEA started (1) ZrC-coating process development by large-scale coater, (2) inspection method development of ZrC coating and (3) irradiation test and post irradiation experiment of ZrC coated particles under contract research which is entrusted to the JAEA and MEXT.
著者
秋元 勇巳 植松 邦彦
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.16, no.3, pp.128-136, 1974

A review is presented of the IAEA-IWGFR Specialists' Meeting on the "Development and Application of Absorber Materials for Fast Reactors" which was held at Dimitrovgrad, USSR, June 4-8, 1973. At the meeting, attention was given mainly to the choice of absorbing materials for the control elements of fast reactors, to the design of absorbing rods and tests of their performance.<BR>About two thirds of the sessions were devoted to the oldest established and the most promising absorber-B<SUB>4</SUB>C. The pre-irradiation properties of B<SUB>4</SUB>C are considered to be fairly thoroughly known already. Good agreement has been seen on the results of compatibility studies. On the other hand, the irradiation behavior of B<SUB>4</SUB>C-specially swelling and He release-stimulated brisk discussion among the participants in respect of the appreciable discrepancy discerned in the results obtained so far and the possible explanations given therefore. Development of the vented control rod is being actively undertaken in most of the countries.<BR>Tantalum and Eu<SUB>2</SUB>O<SUB>3</SUB> attracted attention as promissing alternatives to B<SUB>4</SUB>C. There arises problems, however, on the compatibility of these two materials in the presence of Na. Another difficulty foreseen in the use of Ta rods is cooling during reactor shut-off. For Eu<SUB>2</SUB>O<SUB>3</SUB>, phase stability should be an important problem for future study.
著者
Yoichiro SHIMAZU
出版者
Atomic Energy Society of Japan
雑誌
Journal of Nuclear Science and Technology (ISSN:00223131)
巻号頁・発行日
vol.14, no.11, pp.805-810, 1977-11-25 (Released:2008-04-18)
参考文献数
6

An evaluation is made to estimate the transient xenon behavior in an MSBR for several representative patterns of operation. Such analysis is indispensable for detailed evaluation of reactivity balance under transient conditions. The results are compared with those of a typical PWR. The xenon behavior does not differ between the two types of reactor to the extent that might be expected from the fact that in the MSBR, xenon behavior is additionally conditioned by the processes of migration into the circulating bubbles and into the graphite, as well as by diffusion therein.It is shown that the reactivity transients due to xenon buildup can be held within the range of counteraction by control rod movement for any normal change of reactor output, so long as the reactor is not shut down. After a shutdown, insertion of the control rods will not suffice to override the xenon buildup, but then the fuel processing system could be conveniently utilized to increase the quantity of 233U contained in the fuel and regain required reactivity of the core.
著者
下浦 一邦 筒井 天尊
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.12, no.10, pp.582-585, 1970

Volume reduction of radioactive sludge by de-watering is important in the chemical treatment of radioactive liquid wastes. The de-watering characteristics of super-decanter type centrifuge for ferric hydroxide sludge has been investigated experimentally. The results obtained include the relation of sludge removing efficiency to feed rate, the correlation of centrifugal force with volume reduction factor and with radioactivity eluted from the sludge.<BR>Addition of polymer as coagulating agent is effective in improving the treating capacity and in shortening the settling time after separation. Experiments were performed to determine the conditions for adding the polymer to obtain optimum coagulation of the sludge.
著者
Noboru KOBAYASHI Ichiro YAMAMOTO
出版者
Atomic Energy Society of Japan
雑誌
Journal of Nuclear Science and Technology (ISSN:00223131)
巻号頁・発行日
vol.34, no.3, pp.318-324, 1997-03-25 (Released:2008-04-18)
参考文献数
6
被引用文献数
1

By making use of the isotope approximation; neglecting squares of relative mass differences among the isotopes, the authors derived analytically approximations to ordinary diffusion coefficients in a 3- and 4- component isotope mixture. Moreover, approximations to multi-component diffusion coefficients were given on the analogy of those to the 3- and 4-component coefficients, and these approximations were verified to satisfy constrains on the exact ordinary diffusion coefficients. For 4-component mixture of uranium hexafluoride isotopes, 234UF6-235UF6-236UF6-236UF6, composition dependences of the approximation were equal to those of the exact diffusion coefficients. In addition, relative errors between the exact and the approximations were less than 0.2% for 5-component mixture of krypton 80-82-83-84-86 isotopes.
著者
渡利 一夫 星野 忠也 木下 睦 岩島 清 本田 嘉秀
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.18, no.6, pp.336-345, 1976

原子力開発,それに伴う核燃料再処理工場の稼動,そして低レベル放射性廃液の海洋放出による環境汚染等の問題から放射性Ruの重要性が認識されている。本稿は,放射化学,核燃料再処理,保健物理あるいは海洋放射生態学等の分野における放射性Ruの研究の実情を,それぞれの観点からまとめたものである。
著者
竹上 弘彰 高松 邦吉 伊藤 主税 日野 竜太郎 鈴木 敬一 大沼 寛 奥村 忠彦
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 (ISSN:13472879)
巻号頁・発行日
vol.13, no.1, pp.7-16, 2014

One of the important problems in the control of the Fukushima Daiichi Nuclear Power Plant is the removal of fuel debris. As preparation, a nondestructive inspection method for identifying the position of fuel debris is required. Therefore, we focused on a nondestructive inspection method using cosmic-ray muons, which is utilized for ground investigation. In this study, the applicability of this method for internal visualization of the reactor was confirmed by a preliminary test of the internal visualization of the High-Temperature Engineering Test Reactor (HTTR) of Japan Atomic Energy Agency. By using cosmic-ray muons, main components in the HTTR reactor, such as concrete walls and the reactor core, can be observed from the outside of the containment vessel of the HTTR. From the results of the preliminary examination, it appears that the inspection method with muons is promising for searching for fuel debris in a reactor. Based on the results, we also proposed some improvements of this system for its application to inspection at the Fukushima Daiichi Nuclear Power Station.<br>
著者
若林 二郎 森 寿久 住田 侑 石井 一典 川太 徳夫 飯島 隆
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.28, no.10, pp.913-923, 1986
被引用文献数
1

原子力発電所の運転形態を従来の基底負荷運転から負荷追従運転も含んだ形に拡大していく必要が高まりつつある。電力系統の負荷は季節変化,日変化,さらにより小さな時間スケールの変動成分よりなる複雑な変化を示し,それに対応して原子力発電所を運転するには新しい制御方策の導入と複数種の制御手段の有機的な統合利用が必要となる。<BR>本稿では,現在盛んに開発が進められているこの種技術の実情について、BWR,PWR,ATRの各炉型ごとに要約して紹介する
著者
若林 二郎 森 寿久 住田 侑 石井 一典 川太 徳夫 飯島 隆
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.28, no.10, pp.913-923, 1986
被引用文献数
1

原子力発電所の運転形態を従来の基底負荷運転から負荷追従運転も含んだ形に拡大していく必要が高まりつつある。電力系統の負荷は季節変化,日変化,さらにより小さな時間スケールの変動成分よりなる複雑な変化を示し,それに対応して原子力発電所を運転するには新しい制御方策の導入と複数種の制御手段の有機的な統合利用が必要となる。<BR>本稿では,現在盛んに開発が進められているこの種技術の実情について、BWR,PWR,ATRの各炉型ごとに要約して紹介する
著者
佃 由晃 林 洋 上村 勝一郎 服部 年逸 金子 浩久 師岡 慎一 光武 徹 秋葉 美幸 安部 信明 藁科 正彦 増原 康博 木村 次郎 田辺 朗 西野 祐治 井坂 浩順 鈴木 理一郎
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 (ISSN:13472879)
巻号頁・発行日
vol.1, no.4, pp.384-403, 2002
被引用文献数
1

Nuclear Power Engineering Corporation (NUPEC) has conducted a proving test for thermal-hydraulic performance of BWR fuel (high-burnup 8×8, 9×9) assemblies entrusted by the Ministry of Economy, Trade and Industry (NUPECTH-B Project). The high-burnup 8×8 fuel (average fuel assembly discharge burnup: about 39.5GWd/t), has been utilized from 1991. And the 9×9 fuel (average fuel assembly discharge burnup: about 45GWd/t), has started to be used since 1999. There are two types (A-type and B-type) of fuel design in 9×9 fuel assembly.<BR>Using an electrically heated test assembly which simulated a BWR fuel bundle on full scale, flow induced vibration, pressure drop, critical power under steady state condition and post-boiling transition (post-BT) tests were carried out in an out-of pile test facility that can simulate the high pressure and high temperature conditions of BWRs. This paper completed the results of 9×9 fuel combined with the previously reported results of high-burnup 8×8 fuel.<BR>As a result of NUPEC-TH-B Project, the validity of the current BWR thermal-hydraulic design method was confirmed and the reliability of BWR thermo-hydraulic fuel performance was demonstrated. Based on the test data, a new correlation of the estimation of fuel rod vibration amplitude, new post-BT heat transfer and rewet correlations for the estimation of fuel rod surface temperature were developed.
著者
西原 健司 山岸 功 安田 健一郎 石森 健一郎 田中 究 久野 剛彦 稲田 聡 後藤 雄一
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会和文論文誌 (ISSN:13472879)
巻号頁・発行日
vol.11, no.3, pp.247, 2012 (Released:2012-08-15)

日本原子力学会和文論文誌 Vol. 11, No. 1 (2012), pp.13-19   著者の申し出により,14–16頁の Table 4, 7(1/2), 7(2/2)に誤りがありましたので,PDFの通り訂正いたします。
著者
TAKEDA Hiroshi YAMAMOTO Yutaka
出版者
Atomic Energy Society of Japan
雑誌
Journal of Nuclear Science and Technology (ISSN:00223131)
巻号頁・発行日
vol.13, no.7, pp.372-381, 1976

For analyzing the mixing of particles in a spouted bed, a model is proposed, which assumes that : (a) the spouted bed consists of a spout part characterized by perfect mixing and an annulus part occupied by piston flow, (b) the ingress of particles from annulus into spout takes place within a zone below a depth h below the top of the annulus, and (c) the rate of ingress of particles into the spout is constant throughout the bed. <BR>The time-dependence of the concentration <I>C</I>*(<I>t</I>) of marked particles within the spout can be calculated with this model assuming suitable values for unmeasurable parameters. <BR>The value of <I>C</I>*(<I>t</I>) was measured from mixing experiments undertaken using alumina particles, to which a small batch of marked alumina particles was dropped transiently onto the bed in stable operation. <BR>Comparing the experimental data with the calculated results, it was found that : (a) the mixing of particles in the bed can be satisfactorily described with this model, pro-vided that a suitable correction is added to the quantity of particles present in the spout to account for the existence of mixing in the annulus, whereas the model assumed piston flow ; (b) the upper edge of the ingress zone of particles from the spout into the annulus is located in the conical part of the bed. Increasing the flow rate of spouting air short-ened the cycle time of particles, while the mixing rate within one cycle was not affected to any significant extent by changes in flow rate.
著者
田中 伸和
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.28, no.1, pp.54-57, 1986

This paper reviews vibration phenomena of reactor internal structures in French prototype LMFBR "Super Phénix-1", being observed during its pre-service operation. French efforts to solve the phenomena are outlined, including countermeasures applied to the plant. Also, CRIEPI's study on this issue is briefly explained.
著者
浜口 博 黒田 六郎 清水 恒雄 杉下 竜一郎 束原 巌 山本 隆一
出版者
Atomic Energy Society of Japan
雑誌
日本原子力学会誌 (ISSN:00047120)
巻号頁・発行日
vol.3, no.10, pp.800-805, 1961
被引用文献数
7

The simultaneous determination of microgram to submicrogram amounts of molybdenum, tin, tantalum and tungsten in silicate rocks was arrived at using the Japanese neutron reactor JRR-1. A sample and comparative standard were irradiated simultaneously with a neutron flux of about 3·10<sup>11</sup>n·cm<sup>-2</sup>·sec<sup>-1</sup> for 3 days (intermittently, 5 hr each day).<br>After cooling for a day, the sample was decomposed with sulfuric and hydrofluoric acids in the presence of carriers and lanthanum hold-back carrier. Following the removal of lanthanide activities as fluorides, the fluoride complex of tantalum was extracted by isopropylacetone. Tin and molybdenum was precipitated with hydrogen sulfide from the remaining activities in the aqueous phase, to which boric and tartaric acids were added to mask hydrofluoric acid and tungstate ions, respectively. The α-benzoinoxime precipitation method was then applied for the recovery of bulk of tungsten in the filtrate from the sulfides. Further decontamination chemistry was carried out for each element.<br>The amount of the elements was estimated by comparing <sup>99</sup>Mo(67 hr), <sup>121</sup>Sn(27.5 hr), <sup>182</sup>Ta(111d) and <sup>187</sup>W(23.9 hr) β-activities isolated from the sample with those from the comparative standard. Sensitivities of the method were 1 ppm for Mo and Sn, 0.1 ppm for Ta and 0.01 ppm for W.