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Journal Articles

ORIGEN and ORIGEN-S libraries produced from JENDL-5

Konno, Chikara; Kochiyama, Mami; Hayashi, Hirokazu

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 9 Pages, 2023/05

JENDL-5 released in 2021 includes enough cross section data for neutron activation calculations. Thus we have produced ORIGEN and ORIGEN-S libraries from JENDL 5. We also produced the similar libraries from JENDL/AD-2017 for comparison. Analyses of the JPDR decommissioning data with these libraries demonstrated that the libraries had no problem.

Journal Articles

Calculations for radioactivity evaluation of research reactors for near surface disposal and their application methods

Kochiyama, Mami

Kaku Deta Nyusu (Internet), (133), p.76 - 81, 2022/10

The outline of the presentation at the joint session of Research Committee for Nuclear Data and Subcommittee on Nuclear Data in the Atomic Energy Society of Japan 2022 Autumn Meeting was contributed to Nuclear Data News. As part of the study on the near surface disposal of waste from research facilities, we are studying a method for evaluating the radioactivity inventory of waste generated by the dismantling of research reactors. In the radioactivity evaluation of the research reactor, we have investigated the method of calculating the neutron transport in the reactor and using the obtained neutron spectrum to calculate the activation of the internal structure by the ORIGEN-S code. In recent years, we have introduced and evaluated libraries created based on JENDL-4.0 and JENDL/AD-2017, and we will introduce the status of their examination. And we will introduce how to apply the results obtained by the radioactivity evaluation calculation to burial disposal.

JAEA Reports

Common evaluation procedure radioactivity concentration by theoretical calculation for radioactive waste generated from the decommissioning of research reactors

Okada, Shota; Murakami, Masashi; Kochiyama, Mami; Izumo, Sari; Sakai, Akihiro

JAEA-Testing 2022-002, 66 Pages, 2022/08

JAEA-Testing-2022-002.pdf:2.46MB

Japan Atomic Energy Agency is an implementing organization of burial disposal for low-level radioactive waste generated from research, industrial and medical facilities in Japan. Radioactivity concentrations of the waste are essential information for design of the disposal facility and for licensing process. A lot of the waste subjected to the burial disposal is arising from dismantling of nuclear facilities. Radioactive Wastes Disposal enter has therefore discussed a procedure to evaluate the radioactivity concentrations by theoretical calculation for waste arising from the dismantling of the research reactors facilities and summarized the common procedure. The procedure includes evaluation of radioactive inventory by activation calculation, validation of the calculation results, and determination of the disposal classification as well as organization of the data on total radioactivity and maximum radioactivity concentration for each classification. For the evaluation of radioactive inventory, neutron flux and energy spectra are calculated at each region in the reactor facility using two- or three-dimensional neutron transport code. The activation calculation is then conducted for 140 nuclides using the results of neutron transport calculation and an activation calculation code. The recommended codes in this report for neutron transport calculation are two-dimensional discrete ordinate code DORT, three-dimensional discrete ordinate code TORT, or Monte Carlo codes MCNP and PHITS, and for activation calculation is ORIGEN-S. Other recommendation of cross-section libraries and calculation conditions are also indicated in this report. In the course of the establishment of the procedure, Radioactive Wastes Disposal Center has discussed the commonly available procedure at meetings. It has periodically held to exchange information with external operators which have research reactor facilities. The procedure will properly be reviewed and be revised by reflecting future situ

JAEA Reports

Study on radioactivity evaluation method of research reactors using DORT and MCNP codes

Kochiyama, Mami; Sakai, Akihiro

JAEA-Technology 2022-009, 56 Pages, 2022/06

JAEA-Technology-2022-009.pdf:4.15MB

It is necessary to evaluate radioactivity inventory in wastes before disposal of low-level radioactive wastes generated from dismantling research reactors. It is efficient for owners of each research reactor to use a common radioactive evaluation method in order to comply with the license application for disposal facility. In this report, neutron transport and activation calculations were carried out for the Rikkyo University research reactor in order to examine a common radioactivity evaluation method for burial disposal of radioactive wastes generated by dismantling. We adopted the neutron transport codes DORT and MCNP and the activation code ORIGEN-S with cross-section libraries based on JENDL-4.0 and JENDL/AD-2017. The radioactivity concentrations obtained by the radiochemical analysis and both calculation codes were in agreement by 0.4 to 3 times. Therefore, by appropriately considering this difference, the radioactivity evaluation method by DORT, MCNP and ORIGEN-S can be applied to the radioactivity evaluation for buried disposal. In order to classify wastes from dismantling by clearance or buried disposal method according to their radioactivity levels, we also created radioactivity concentration distributions in the concrete area and graphite thermal column area.

Journal Articles

SCALE6.2 ORIGEN library produced from JENDL/AD-2017

Konno, Chikara; Kochiyama, Mami; Hayashi, Hirokazu

JAEA-Conf 2021-001, p.132 - 137, 2022/03

A SCALE6.2 ORIGEN library was produced with the AMPX-6 code from JENDL Activation Cross Section File for Nuclear Decommissioning 2017 (JENDL/AD-2017). For validation of the libraries, JPDR activation calculation was performed with ORIGEN and the libraries, which demonstrated the library had no problem.

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-2, JRR-3 and hot laboratory facilities

Tobita, Minoru*; Haraga, Tomoko; Sasaki, Takayuki*; Seki, Kotaro*; Omori, Hiroyuki*; Kochiyama, Mami; Shimomura, Yusuke; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2019-016, 72 Pages, 2020/02

JAEA-Data-Code-2019-016.pdf:2.67MB

In the future, radioactive wastes which generated from research and testing reactors in Japan Atomic Energy Agency are planning to be buried for the near surface disposal. 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 JRR-2, JRR-3 and Hot laboratory facilities. In this report, we summarized the radioactivity concentrations of 25 radionuclides ($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{93}$$Mo, $$^{99}$$Tc, $$^{108m}$$Ag, $$^{126}$$Sn, $$^{129}$$I, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{233}$$U, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239}$$Pu, $$^{240}$$Pu, $$^{241}$$Pu, $$^{241}$$Am, $$^{243}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of those samples.

Journal Articles

Performance of a remotely located muon radiography system to identify the inner structure of a nuclear plant

Fujii, Hirofumi*; Hara, Kazuhiko*; Hashimoto, Shugo*; Ito, Fumiaki*; Kakuno, Hidekazu*; Kim, S.*; Kochiyama, Mami; Nagamine, Kanetada*; Suzuki, Atsuto*; Takada, Yoshihisa*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2013(7), p.073C01_1 - 073C01_20, 2013/07

 Times Cited Count:25 Percentile:76.83(Physics, Multidisciplinary)

JAEA Reports

Performance evaluation of multiple gamma-ray detection instrument by non-destructive measurement of radioactive waste sample

Kochiyama, Mami; Haraga, Tomoko; Kameo, Yutaka; Takahashi, Kuniaki

JAEA-Technology 2011-038, 26 Pages, 2012/02

JAEA-Technology-2011-038.pdf:2.94MB

A nondestructive measurement of gamma-ray emitting nuclides has been studied and Multiple gamma-ray Detection Instrument is newly constructed with 4 detection units consisting of Ge and BGO detectors. Compton scattering was decreased by the combination of Ge and BGO detectors. This instrument was applied to the detection of interested nuclides in radioactive waste sample, which contains significant amount of Co-60, and detection limit of the interested gamma-ray emitting nuclides were improved by a factor of 4 to 12 times than single gamma-ray spectrometer. As for Nb-94, the radioactivity determined from measurements using Multiple gamma-ray Detection Instrument in this sample was agreed with that determined by radiochemical analysis within 15%. It was confirmed that the instrument are useful for radioactivity determination of gamma-ray emitting nuclides in radioactive waste.

Oral presentation

Non-destructive measurement of radioactive wastes by multiple $$gamma$$-ray detector; Detection limits of metallic radioactive wastes

Kochiyama, Mami; Haraga, Tomoko; Kameo, Yutaka; Takahashi, Kuniaki

no journal, , 

no abstracts in English

Oral presentation

Development of analytical method of resonance ionization mass spectrometry using a rotating electric field for long-lived nuclides; Measurement using laser ablation employed as atomization method

Kochiyama, Mami; Ishimori, Kenichiro; Toshimitsu, Masaaki; Katayama, Atsushi; Saito, Naoaki*; Omura, Hideki*; Takahashi, Kuniaki

no journal, , 

no abstracts in English

Oral presentation

Development of confirmation methods of waste packages to radioactive wastes generated from research facilities, 2; Construction of radiochemical analytical scheme for metal samples

Shimomura, Yusuke; Kochiyama, Mami; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka

no journal, , 

no abstracts in English

Oral presentation

Production of MAXS/AD-2017 multigrioup library and its test

Konno, Chikara; Kochiyama, Mami

no journal, , 

A multi-group neutron activation cross-section library (MAXS/AD-2017) with the MAXS format was produced from JENDL Activation Cross Section File for Nuclear Decommissioning 2017 (JENDL/AD-2017) released in 2018. As one of tests of MAXS/AD-2017, JPDR activation analysis was performed with ORIGEN-S and its library generated from MAXS/AD-2017.

Oral presentation

Radioactivity calculation of JPDR biological shielding concrete and examination of radioactivity evaluation technique for trench-type disposal

Kochiyama, Mami; Sakai, Akihiro; Konno, Chikara

no journal, , 

We performed activation calculations using DORT and ORIGEN-S for biologically shielded concrete in the power test reactor JPDR. By comparing the calculated values with the measured values of concrete samples. We evaluated the appropriate radioactivity concentration and evaluated the possibility of trench-type disposal and the target nuclides.

Oral presentation

Production of multi-group libraries for ORIGEN in SCALE6.2 from JENDL/AD-2017

Konno, Chikara; Kochiyama, Mami

no journal, , 

Multi-group neutron activation cross-section libraries for the ORIGEN code in the SCALE6.2 code system was produced with the AMPX-6 code from JENDL Activation Cross Section File for Nuclear Decommissioning 2017 (JENDL/AD-2017) released in 2018. For V&V of the libraries, JPDR activation calculation was performed with ORIGEN and the libraries.

Oral presentation

Study on group structure in DORT calculations for decommissioning activation estimation

Konno, Chikara; Kochiyama, Mami

no journal, , 

Activation estimation results in reactor decommissioning depend on neutron fluxes used in the estimation. Thus we studied how neutron fluxes changed in DORT calculations corresponding to neutron group structures; 200, 56, 49, 47 and 44 group structures adopted in the SCALE 6.2 ORIGEN library and a 48 group structure used in JAEA previous JPDR analysis. The calculated DORT neutron flux with JENDL-4.0 were compared with those by using MCNP. The comparison showed that the thermal neutron flux of the 200 group agreed with the MCNP one, while that of the 48 group underestimated by $$sim$$20%, that of the 47 group underestimated by $$sim$$30% and those of the 56, 49 and 44 groups underestimated by $$sim$$50%.

Oral presentation

Present status of activation cross section data for nuclear reactor decommissioning, 4; Examination status of activation calculation of radioactive waste generated from research reactors for near surface disposal

Kochiyama, Mami; Sakai, Akihiro

no journal, , 

As part of the study on the burial disposal of waste from research facilities, we are studying a method for evaluating the radioactivity inventory of waste generated by the dismantling of research reactors. In the radioactivity evaluation of the research reactor, we have investigated the method of calculating the neutron transport in the reactor and using the obtained neutron spectrum to calculate the activation of the internal structure by the ORIGEN-S code. In recent years, we have introduced and evaluated libraries created based on JENDL-4.0 and JENDL/AD-2017, and we will introduce the status of their examination. And we will introduce how to apply the results obtained by the radioactivity evaluation calculation to burial disposal.

Oral presentation

ORIGEN and ORGEN-S activation libraries produced from JENDL-5

Konno, Chikara; Kochiyama, Mami; Hayashi, Hirokazu

no journal, , 

We have produced ORIGEN and ORIGEN-S libraries from JENDL 5 released in 2021 in order to use JENDL 5 in the codes. Analysis results of the JPDR decommissioning data with these libraries were similar to those with the libraries bundled in ORIGEN and ORIGEN-S, which indicated that the produced libraries had no problem

Oral presentation

Toward the near surface disposal of wastes from research facilities; Study of radioactivity evaluation methods for research reactors

Kochiyama, Mami; Tomioka, Dai; Totsuka, Masayoshi*; Nakata, Hisakazu; Sakai, Akihiro

no journal, , 

Japan Atomic Energy Agency is proceeding with plans for the near surface disposal of low-level radioactive waste generated from research institutes and medical institutions in Japan. In order to dispose of the radioactive waste generated by the dismantling of the research reactor, it is necessary to evaluate the radioactivity concentration in the waste. We report on the status of study of radioactivity evaluation methods for dismantling waste generated from research reactors.

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