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JAEA Reports

Analysis of the radioactivity concentrations in radioactive waste generated from JPDR Facility

Tobita, Minoru*; Haraga, Tomoko; Endo, Tsubasa*; Omori, Hiroyuki*; Mitsukai, Akina; Aono, Ryuji; Ueno, Takashi; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2021-013, 30 Pages, 2021/12

JAEA-Data-Code-2021-013.pdf:1.47MB

Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JPDR facility. In this report, we summarized the radioactivity concentrations of 21 radionuclides ($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{41}$$Ca, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{rm 108m}$$Ag, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{rm 166m}$$Ho, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239}$$Pu, $$^{240}$$Pu, $$^{241}$$Am, $$^{243}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2018-2019.

JAEA Reports

Study on the radioactivity evaluation method of biological shielding concrete of JPDR for near surface disposal

Kochiyama, Mami; Okada, Shota; Sakai, Akihiro

JAEA-Technology 2021-010, 61 Pages, 2021/07

JAEA-Technology-2021-010.pdf:3.56MB
JAEA-Technology-2021-010(errata).pdf:0.75MB

It is necessary to evaluate the radioactivity inventory in wastes in order to dispose of radioactive wastes generated from dismantling nuclear reactor in the shallow ground. In this report, we examined radioactivity evaluation method for near surface disposal about biological shield concrete near the core generated from the dismantling of JPDR. We calculated radioactive concentration of the target biological concrete using the DORT code and the ORIGEN-S code, and we estimated radioactivity concentration Di (Bq/t). For DORT calculation, the cross-section library created from the MATXSLIB-J40 file from JENDL-4.0 was used, and for ORIGEN-S, the attached library of SCALE6.0 was used. As a result of comparing the calculation results of the radioactivity concentration with the past measured values in the radial direction and the vertical direction, we found that the trends were generally the same. We calculated radioactive concentration of the target biological concrete Di (Bq/t), and we compared with the estimated Ci (Bq/t) equivalent to the dose criteria of trench disposal calculated for 140 nuclides. As a result we inferred that the except for about 2% of target waste could be disposed of in the trench disposal facility. We also preselected important nuclides for trench disposal based on the ratios (Di/Ci) for each nuclide, H-3, C-14, Cl-36, Ca-41, Co-60, Sr-90, Eu-152 and Cs-137 were selected as important nuclides.

JAEA Reports

Analysis of the radioactivity concentrations in low-level radioactive waste generated from JRR-3 and JPDR facilities

Tsuchida, Daiki; Haraga, Tomoko; Tobita, Minoru*; Omori, Hiroyuki*; Omori, Takeshi*; Murakami, Hideaki*; Mitsukai, Akina; Aono, Ryuji; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2020-022, 34 Pages, 2021/03

JAEA-Data-Code-2020-022.pdf:1.74MB

Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JRR-3 and JPDR. In this report, we summarized the radioactivity concentrations of 22 radionuclides($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{41}$$Ca, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{rm 108m}$$Ag, $$^{133}$$Ba, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{rm 166m}$$Ho, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239+240}$$Pu, $$^{241}$$Am, $$^{243}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of the samples.

Journal Articles

Corrosion cracking of JPDR the first Japanese light water reactor

Tsukada, Takashi; Soma, Yasutaka

Hozengaku, 19(4), p.37 - 44, 2021/01

Corrosion Cracking phenomena in JPDR (Japan Power Demonstration Reactor) the first Japanese Light Water Reactor is reviewed. This review describes two major cracking failure. The first was found during inspection in 1966 as the cracking failure on weld-overlay cladding at the inner wall of the top head. A series of analysis showed that some of the cracks reached the base metal across the weld boundaries and further penetrated into the vessel wall. Significant depletion of ferrite content was detected in manually welded part considered to assisted the cracking. These inspection result in improvement of the welding procedure and no similar failures have been reported in Japanese reactor. This mode of failure gave rise to a new research field studying the corrosion fatigue behavior of low alloy steel because of importance to assess pressure boundary of the reactor. The experiment of JPDR also contributed to the establishment of international cooperation for studying EAC (environmentally assisted cracking). The second failure was found in 1972 near the welded part between stainless piping and safe end. The extensive research concluded that this failure was caused by Stress Corrosion Cracking.

JAEA Reports

Analysis of the radioactivity concentrations in low-level radioactive waste generated from JPDR and JRR-4

Aono, Ryuji; Mitsukai, Akina; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2020-006, 70 Pages, 2020/08

JAEA-Data-Code-2020-006.pdf:2.59MB

Radioactive wastes which generated from research and testing reactors in Japan Atomic Energy Agency are planning to be buried at the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes by the time it starts disposal. In order to contribute to this work, we collected and analyzed the samples generated from JPDR and JRR-4. In this report, we summarized the radioactivity concentrations of 19 radionuclides ($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{99}$$Tc, $$^{rm 108m}$$Ag, $$^{129}$$I, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239+240}$$Pu, $$^{241}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of those samples.

JAEA Reports

Study of decommissioning cost evaluation technique for nuclear reactor dismantlement; Calculation of decommissioning cost by COSMARD

Oshima, Soichiro; Shiraishi, Kunio; Shimada, Taro; Sukegawa, Takenori; Yanagihara, Satoshi

JAERI-Tech 2005-046, 46 Pages, 2005/09

JAERI-Tech-2005-046.pdf:3.43MB

A model for estimating decommissioning costs consisting of labor cost, device cost and expense, was developed for items which OECD/NEA had standardized, and was installed into the computer system for planning and management of reactor decommissioning (COSMARD). Input data files and databases for the decommissioning of JPDR were prepared, and the decommissioning cost was calculated with COSMARD. In addition, the decommissioning cost for a large scale BWR power plant was also calculated on the assumption of the advantage of scale. The calculations have shown that it is useful and efficient for studying the decommissioning costs for nuclear reactors to apply the COSMARD with database for cost estimation to the decommissioning cost calculation.

Journal Articles

Numerical analysis of fractional distillation characteristics for radioactive metallic waste vaporized in the shape of atomic beam

Akaoka, Katsuaki; Maruyama, Yoichiro

Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(2), p.127 - 134, 2005/06

The fractional distillation characteristics of the materials used for the reactor pressure vessel made of ASTM A302B and the structures in reactor made of SUS304 which are the radioactive metallic waste of Japan Power Demonstration Reactor (JPDR) were analyzed numerically. In the simulation, the vaporization rates of the components of the waste were calculated by using the Langmuir's equation and Henry's law. As the result of simulation, it was calculated that $$^{152}$$Eu, $$^{154}$$Eu, $$^{14}$$C and $$^{94}$$Nb can be reduced to less than clearance level by the fractional distillation. On the ASTM A302B case, it was pointed out that the other radioactive nuclei which are $$^{54}$$Mn, $$^{55}$$Fe, $$^{60}$$Co, $$^{59}$$Ni and $$^{63}$$Ni satisfy clearance level after 77 years cooling down. On the SUS304 case, it was pointed out that $$^{59}$$Ni and $$^{63}$$Ni must be separated to satisfy clearance level using isotope separation.

JAEA Reports

The Technological study on the decommissioning of nuclear facility, etc. in the Tokai Research Establishment

Tomii, Hiroyuki; Matsuo, Kiyoshi*; Shiraishi, Kunio; Kato, Rokuro; Watabe, Kozo; Higashiyama, Yutaka; Nagane, Satoru*; Hanawa, Yukimitsu*

JAERI-Tech 2005-017, 65 Pages, 2005/03

JAERI-Tech-2005-017.pdf:3.79MB

no abstracts in English

Journal Articles

Cost estimation method for decommissioning of nuclear facilities

Tomii, Hiroyuki; Matsuo, Kiyoshi*; Shiraishi, Kunio; Watabe, Kozo; Saiki, Hideo*; Kawatsuma, Shinji*; Rindo, Hiroshi*; Zaitsu, Tomohisa*

Dekomisshoningu Giho, (31), p.11 - 20, 2005/03

no abstracts in English

Journal Articles

Numerical analysis of fractional distillation for radioactive metal

Akaoka, Katsuaki; Maruyama, Yoichiro

RIST News, (39), p.23 - 31, 2005/03

For the separation of radionuclide from the radioactive metallic waste generated by the decommissioning of nuclear facilities, a new method combined with the distillation and laser separation is being studied. The characteristics of fractional distillation for duralumin were analyzed numerically using the Henry's law and the Langmuir's equation, and its result agreed well with the experiment. Next, the fractional distillation characteristics of the materials used for the structures in reactor made of SUS304 which are the radioactive metallic waste of Japan Power Demonstration Reactor (JPDR) were analyzed numerically. As the result of the simulation, it was calculated that the radioactive metallic waste will be reduced to less than 1/100.

JAEA Reports

Numerical analysis of fractional distillation characteristics for radioactive metallic waste

Akaoka, Katsuaki; Maruyama, Yoichiro

JAERI-Research 2004-012, 12 Pages, 2004/08

JAERI-Research-2004-012.pdf:3.52MB

The fractional distillation characteristics at between 0 $$^{circ}$$C and 2500 $$^{circ}$$C(the rate is 200 $$^{circ}$$C/h) of radioactive metallic waste for JPDR which mainly consists of stainless steel were analyzed numerically. In the simulation, the vaporization rates of the components of JPDR waste were calculated by using the Langmuir's equation and Henry's law. As the results, it was calculated that $$^{152,154}$$Eu, $$^{14}$$C and $$^{94}$$Nb can be removed by the fractional distillation. On the other hand, $$^{54}$$Mn and $$^{55}$$Fe can be reduced by cooling them for about 30 years. Therefore, by removing $$^{59,63}$$Ni and $$^{60}$$Co using laser separation method, it will be possible to reduce the radioactive metallic waste by less than one one-hundredth.

Journal Articles

Decommissioning project feedback experience in the Japan Atomic Energy Research Institute

Yanagihara, Satoshi; Tachibana, Mitsuo; Miyajima, Kazutoshi

Proceedings of International Conference; Decommissioning Challenges (CD-ROM), 8 Pages, 2003/00

Several decommissioning projects are on going and studies on decommissioning issues are in progress in JAERI. The JPDR and JRTF decommissioning projects have been set up as demonstration programs for future decommissioning large nuclear facilities. Therefore, efforts have been made not only to dismantle the facilities but also to collect data and lessons learnt on dismantling activities. The data and lessons learnt have been analyzed to produce the database for future decommissioning projects by categorizing into manpower expenditure, radiation dose and waste generation in project data, and safety aspect, waste management, work efficiency considerations in lessons learnt. respectively. The feedback experience has been effectively contributed to various areas on decommissioning such as studies on regulatory systems and planning of other dismantling projects. This paper deals with decommissioning experience and lessons learned in JAERI.

Journal Articles

Development of computer systems for planning and management of reactor decommissioing

Yanagihara, Satoshi

Nihon Genshiryoku Gakkai-Shi, 44(10), p.734 - 737, 2002/10

no abstracts in English

Journal Articles

Decommissioning of nuclear power plants; View and issues

Yanagihara, Satoshi

Science & Technology Journal, 11(10), p.22 - 23, 2002/10

no abstracts in English

Journal Articles

Development of dual arm manipulators with remote control system

Tachibana, Mitsuo; Shimada, Taro; Yanagihara, Satoshi

Nihon Kikai Gakkai Dai-8-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.489 - 492, 2002/06

A remote dismantling robot was developed for decommissioning in nuclear facilities. The remote dismantling robot consists of two electrical powered manipulators, end-effectors and a control system. To realize stable dismantling operation remotely, the remote dismantling robot is designed from view point of proper control in coping with different activity conditioning by feedback of image and of force to the control system. The image feedback was considered to obtain accurate positioning of the end-effectors and the force feedback was considered to supply proper force for direct interaction with an object. Motion tests were performed to verify the remote dismantling robot and its control system. As a result, it was confirmed that the remote dismantling activities such as cutting, radioactivity measurement, decontamination were conducted efficiently by using the image feedback and the force feedback.

Journal Articles

Automatic measurement of low level contamination on concrete surfaces

Tachibana, Mitsuo; Ito, Hirokuni; Shimada, Taro; Yanagihara, Satoshi

Proceeding of International Waste Management Symposium 2002 (WM '02) (CD-ROM), 8 Pages, 2002/00

Automatic measurement of radioactivity is necessary for considering cost effectiveness in final radiological survey of building structures in decommissioning nuclear facilities. The RAPID (radiation measuring pilot device for surface contamination) was developed to be applied to automatic measurement of low level contamination on concrete surfaces. The RAPID has a capability to measure contamination with detection limit of 0.14 Bq/cm$$^{2}$$ for $$^{60}$$Co in 30 seconds of measurement time and its efficiency is evaluated to be 5 m$$^{2}$$/h in a normal measurement option. It was confirmed that low level contamination on concrete surfaces could be surveyed by the RAPID efficiently compared with direct measurement by workers through its actual application.

JAEA Reports

Development of computer systems for planning and management of reactor decommissioning; A Study on influence of work difficulty factors on project management data and simplification of work breakdown structures (Contract research)

Oshima, Soichiro; Sukegawa, Takenori; Shiraishi, Kunio; Yanagihara, Satoshi

JAERI-Tech 2001-086, 83 Pages, 2001/12

JAERI-Tech-2001-086.pdf:5.23MB

Project management data on dismantling the Japan Power Demonstration Reactor (JPDR) was calculated using the Code System for Planning and Management of Reactor Decommissioning (COSMARD), and then its validity was studied by comparing the calculation results with actual data. In addition, work breakdown structure models and database were modified to meet an evaluation with changing work difficulty of preparation and cleanup activities, and calculations were further conducted to analyze feasibility by changing various conditions on cutting and conditioning activities. As the results, COSMARD was verified to be useful by confirming calculation capability on reflection of actual work conditions and relatively good agreement between actual data and calculations. Moreover, it was cleared that main parameters such as work difficulty of preparation and cleanup activities and the cutting speed in demolition work could affect to manpower within 30% in each calculations.

JAEA Reports

Data analysis on worker dose in dismantling of Japan Power Demonstration Reactor (JPDR) (Contract research)

Shiraishi, Kunio; Sukegawa, Takenori; Yanagihara, Satoshi

JAERI-Data/Code 2001-028, 86 Pages, 2001/11

JAERI-Data-Code-2001-028.pdf:6.31MB

The data on worker dose in dismantling of the Japan Power Demonstration Reactor (JPDR) was analyzed to characterize its features. It was appeared from the study that the collective dose to the workers was 306 man-mSv, in which maximum individual dose was 8.5 mSv, almost all doses were received in the activities for dismantling of reactor internals, the reactor pressure vessel and the biological shield, and that the worker dose distribution was similar to that in the maintenanee of the facilities which was characterized by the hybrid log normal distribution model. Farthermore, it was found that the dismantling activities were categorized into three groups depending on dose rates in workplaces, then contribution factors for radiation exposure in terms of dose rates in different groups were derived based on the analysis. The study would be useful for estimation of worker dose in future decommissioning of commercial nuclear power plants in Japan.

JAEA Reports

Study on residual radioactive inventory estimation in reactor decommissioning program (Contract research)

Sukegawa, Takenori; Hatakeyama, Mutsuo; Yanagihara, Satoshi

JAERI-Tech 2001-058, 81 Pages, 2001/09

JAERI-Tech-2001-058.pdf:5.98MB

In general, neutron transport and activation calculation codes are used for residual radioactive inventory estimation; however, it is essential to verify calculations by measurement results because of geometrical complexity of the reactor and so on. The comparison between measured and calculated radioactivity in the JPDR core components showed a relatively good agreement (factor of 2), and it was cleared that water content and weight ratio of steel bars to concrete materials significantly influenced the neutron flux distribution in the biological shield (factor of 2-10 error). The measured radioactivity inside of the reactor pressure vessel wall and at the inner part of the biological shield was compared in detail with the calculations to verify the methodology applied to calculations of radioisotope production. Then it was found that the radioactive inventory could be estimated accurately with combination of calculations and measurement of radioactivity in samples and dose rate distribution for planning of dismantling activities.

Journal Articles

Development of computer systems for planing and management of reactor decommissioning; Estimation of project management data on Dismantling Tokai Power Station

Yanagihara, Satoshi; Oshima, Soichiro; Sukegawa, Takenori; Tanabe, Norio*; Takaya, Junichi*; Kiuchi, Yoshio*; Yokota, Shuichi*

Nihon Genshiryoku Gakkai-Shi, 43(5), p.493 - 502, 2001/05

 Times Cited Count:1 Percentile:12.49(Nuclear Science & Technology)

no abstracts in English

167 (Records 1-20 displayed on this page)