Radiological dose from seafood ingestion; A Global summary from 40 years of study

Johansen, M. P.*; Gwynn, J. P.*; Carpenter, J. G.*; Charmasson, S.*; McGinnity, P.*; Mori, Airi; Orr, B.*; Simon-Cornu, M.*; Osvath, I.*

Critical Reviews in Environmental Science and Technology, 55(6), p.422 - 445, 2025/00

https://doi.org/10.1080/10643389.2024.2413202

Introduction and implementation of physical protection measures including trustworthiness program at Tokai Reprocessing Facilities

Nakamura, Hironobu; Kimura, Takashi; Yamazaki, Katsuyuki; Kitao, Takahiko; Tasaki, Takashi; Iida, Toru

Proceedings of International Conference on Physical Protection of Nuclear Material and Nuclear Facilities (Internet), 9 Pages, 2018/09

After the accident of Fukushima Daiichi Nuclear Power Station, to develop effective security measures based on the lesson learned from such crisis and to meet the IAEA Nuclear Security Recommendations (INFCIRC/225/Rev.5), NRA in Japan made a partial amendment of the regulations concerning the reprocessing activity in 2012. The Tokai reprocessing facility implemented all of those security measures by the end of March 2014. Those new measures help us to keep high degree of security level and contributed to our planned operations to reduce the potential risk of the plant. On the other hand, the trustworthiness program was newly introduced in 2016, based on the trustworthiness policy determined by NRA. The implementing entity of the program is JAEA for the Tokai Reprocessing Facility and is required for both the persons afford unescorted access to Category I and II, CAS/SAS, and the persons afford access to the sensitive information. Those who are involved this program will be judged before engaging the work whether they might act as insider to cause or assist radiological sabotage or unauthorized removal of nuclear material, or leak sensitive information. The program is expected as a measure against insider at reprocessing facilities, and is expected to be enforced around the autumn of 2017. As well as the establishment of security measures, the promoting nuclear security culture for all employees was a big challenge. The Tokai reprocessing facility have introduced several security culture activities, such as case study education of security events done by a small group and putting up the security culture poster and so on. This paper presents introduction and implementation with effectiveness of security measures in the Tokai reprocessing facilities and the future security measures applied to the reprocessing facilities are discussed.

Rust and corrosion mechanism of carbon steel in dilute chloride solution at low dose rates

Motooka, Takafumi

QST-M-8; QST Takasaki Annual Report 2016, P. 73, 2018/03

https://repo.qst.go.jp/records/73811

Previous corrosion test of carbon steel in dilute artificial seawater under Co-60 -ray irradiation has indicated that corrosion rate was enhanced at absorbed dose rates: 100 Gy/h and rust color was changed from black to dark brown. In the present study, the corrosion mechanism of carbon steel under Co-60 -ray irradiation was investigated by identification of rust. rays enhanced oxidation of iron ions from di-valent to tri-valent. Rust formed under irradiation had higher oxidation state.

Non-volcanic seismic swarm and fluid transportation driven by subduction of the Philippine Sea slab beneath the Kii Peninsula, Japan

Kato, Aitaro*; Saiga, Atsushi; Takeda, Tetsuya*; Iwasaki, Takaya*; Matsuzawa, Toru*

Earth, Planets and Space (Internet), 66(1), p.86_1 - 86_8, 2014/12

https://doi.org/10.1186/1880-5981-66-86

To understand the mechanism of an intensive non-volcanic seismic swarm in the Kii Peninsula, Japan, we used a dense seismic linear array to measure fine-scale variations of seismic velocities and converted teleseismic waves. A low-velocity anomaly confined to just beneath the seismic swarm area is clearly imaged, which spatially correlates with an uplifted surface area, and a highly conductive and strong attenuative body. These results suggest that fluids such as partial melt or water are present beneath this non-volcanic seismic swarm area. It is notable that the island arc Moho below the seismic swarm area is at depths of ca. 32 km in the northern part of the seismic swarm area, and shallows to ca. 20 km towards the south, due to an upwardly raised structure of serpentinized mantle wedge. In addition, we show that hydrated oceanic crust of the subducting Philippine Sea slab is characterized by low-velocities with a high Poisson's ratio at depths shallower than 40 km. Water released from the subducting oceanic crust could cause serpentinization of the mantle wedge and infiltration into the forearc base of the overlying plate. The interaction between dehydration of the subducting oceanic crust and hydration of the mantle wedge and overlying plate exerts an important role in driving the non-volcanic seismic swarm activity in the Kii Peninsula.

Characterization of rust layer formed on Fe, Fe-Ni and Fe-Cr alloys exposed to Cl-rich environment by Cl and Fe K-edge XANES measurements

Konishi, Hiroyuki; Yamashita, Masato*; Uchida, Hitoshi*; Mizuki, Junichiro

Materials Transactions, 46(2), p.329 - 336, 2005/02

https://doi.org/10.2320/matertrans.46.329

Chloride in atmosphere considerably reduces the corrosion resistance of conventional weathering steel containing a small amount of Cr. Ni is an effective anticorrosive element for improving the corrosion resistance of steel in a Cl-rich environment. In order to clarify the structure of the protective rust layer of weathering steel, Cl and Fe K-edge X-ray absorption near edge structure (XANES) spectra of atmospheric corrosion products (rust) formed on Fe, Fe-Ni and Fe-Cr alloys exposed to Cl-rich atmosphere were measured. The Fe K-XANES measurements enable the characterization of a mixture of iron oxides such as rust. The chemical composition of the rust was determined by performing pattern fitting of the measured spectra. All the rust is composed mainly of goethite, akaganite, lepidocrocite and magnetite. Among these iron oxides, akaganite in particular is the major component in the rust. Additionally, the amount of akaganite in the rust of Fe-Ni alloy is much greater than that in rust of Fe-Cr alloy. Akaganite is generally considered to facilitate the corrosion of steel, but our results indicate that akaganite in the rust of Fe-Ni alloy is quantitatively different from that in rust of Fe-Cr alloy and does not facilitate the corrosion of steel. The shoulder peak observed in Cl K-XANES spectra reveals that the rust contains a chloride other than akaganite. The energy of the shoulder peak does not correspond to that of any well-known chlorides. In the measured spectra, there is no proof that Cl, by combining with the alloying element, inhibits the alloying element from acting in corrosion resistance. The shoulder peak appears only when the content of the alloying element is lower than a certain value. This suggests that the generation of the unidentified chloride is related to the corrosion rate of steel.

Trust destruction as the cause of social unrest for nuclear energy and restoration

Sobajima, Makoto

Nihon Genshiryoku Gakkai-Shi, 43(8), p.754 - 760, 2001/08

https://doi.org/10.3327/jaesj.43.754

no abstracts in English

Analysis of WITCH/LINER experiments on heat transfer between gas-agitated steel melt and vertical wall

Maruyama, Yu; Sugimoto, Jun

Journal of Nuclear Science and Technology, 36(10), p.914 - 922, 1999/10

https://doi.org/10.3327/jnst.36.914

no abstracts in English

Core melt behaviors and thermal properties in LWR severe accident

Sugimoto, Jun; Uetsuka, Hiroshi; Hidaka, Akihide; Maruyama, Yu; Yamano, N.; Hashimoto, Kazuichiro

Thermophysical Properties 17 (17th Japan Symp. 1996), 0, p.163 - 166, 1996/00

no abstracts in English

Analytical studies of blowdown thrust force and elastic-plastic behavior of pipe at pipe rupture accident

; Ueda, Shuzo

J. Pressure Vessel Technol., 108, p.175 - 181, 1986/00

https://doi.org/10.1115/1.3264766

no abstracts in English

Transient analysis of blowdown thrust force under PWR LOCA

; ;

Nucl.Eng.Des., 75, p.157 - 168, 1982/00

https://doi.org/10.1016/0029-5493(83)90087-0

no abstracts in English