Unveiling the effects of Mn, Cr, Al, and Si on the low-temperature tempering behaviors of high-carbon martensite

Zhang, Y.*; Marusawa, Kenji*; Kudo, Kohei*; Morooka, Satoshi; Gong, W.; Harjo, S.; Miyamoto, Goro*; Furuhara, Tadashi*

Journal of Materials Science & Technology, 275, p.250 - 259, 2026/12

https://doi.org/10.1016/j.jmst.2026.04.015

Directional fast neutron detectors for neutron source surveys over large areas

Hironaka, Kota; Koizumi, Mitsuo; Mochimaru, Takanori*; Takahashi, Tone; Yamanishi, Hirokuni*; Wakabayashi, Genichiro*

Nuclear Instruments and Methods in Physics Research A, 1090, p.171675_1 - 171675_7, 2026/10

https://doi.org/10.1016/j.nima.2026.171675

The KTB monazite fission-track profile; Initial insights into ultra-low temperature thermochronology from a natural laboratory

Nakajima, Toru*; Sueoka, Shigeru; Fukuda, Shoma; King, G. E.*; Tagami, Takahiro*

Earth and Planetary Science Letters, 690, p.120184_1 - 120184_9, 2026/09

https://doi.org/10.1016/j.epsl.2026.120184

Magnetic properties of NdCrGeTiO having spin- antiferromagnetic alternating chains of Cr spins and dimers of Nd moments

Hase, Masashi*; Ikeda, Manami*; Hagihara, Masato; Kubota, Masato

Journal of Magnetism and Magnetic Materials, 653, p.174193_1 - 174193_7, 2026/09

https://doi.org/10.1016/j.jmmm.2026.174193

Measuring the velocity of fragments produced by high-repetition-rate nanosecond laser pulses; A Technique to visualize the fragments for laser decontamination

Kosuge, Atsushi; Ando, Kota*; Yamamoto, Keisuke*; Nakajima, Takashi*

Optics & Laser Technology, 201, p.115269_1 - 115269_6, 2026/09

https://doi.org/10.1016/j.optlastec.2026.115269

Probabilistic fracture mechanics benchmarking study of PASCAL-SP code with xLPR code regarding primary water stress corrosion cracking

Mano, Akihiro; Yamaguchi, Yoshihito; Katsuyama, Jinya

International Journal of Pressure Vessels and Piping, 222, p.105792_1 - 105792_11, 2026/08

https://doi.org/10.1016/j.ijpvp.2026.105792

A probabilistic fracture mechanics (PFM) analysis code, PASCAL-SP, has been developed by the Japan Atomic Energy Agency (JAEA) to evaluate the failure probability of piping within nuclear power plants while considering age-related degradations such as stress corrosion cracking and fatigue for both pressurized water reactor and boiling water reactor environments. To strengthen the confidence in the results of PASCAL-SP, a benchmarking study was performed with the PFM analysis code, xLPR, which was developed by the U.S.NRC in collaboration with EPRI. In this benchmarking study, deterministic and probabilistic analyses are performed using common analysis conditions. This paper presents the details of these conditions and comparisons of the results between the two aforementioned codes. Both codes were found to provide nearly the same results in both deterministic and probabilistic analyses for a dissimilar metal weld subjected to primary water stress corrosion cracking.

Applicability of instrumented indentation for assessing allowable flaw sizes of circumferentially flawed stainless steel piping

Ha, Yoosung; Negyesi, M.*; Hasegawa, Kunio; Lacroix, V.*

Journal of Nondestructive Evaluation, Diagnostics and Prognostics of Engineering Systems, 9(3), p.031001_1 - 031001_6, 2026/08

https://doi.org/10.1115/1.4071687

Real-time inversion of radioactive source distribution using air dose rate measurements via least absolute shrinkage and selection operator method

Shi, W.*; Machida, Masahiko; Okamoto, Koji*; Luo, X.*; Feng, W.*; Liu, X.*

Reliability Engineering & System Safety, 272, Part1, p.112538_1 - 112538_18, 2026/08

http://doi.org/10.1016/j.ress.2026.112538

The reliability of emergency response in severe nuclear accidents critically depends on robust real-time monitoring of radioactive source distributions. However, this safety function is challenged by physical constraints that create monitoring blind spots and by the inadequacy of static methods in tracking dynamic releases. To enhance the reliability and robustness of source term estimation, this study proposes a dynamic reconstruction framework based on LASSO regression with temporal regularization. A sliding-window time-penalty mechanism is introduced, imposing -norm constraints on inter-step source variations to ensure physical continuity. The contribution matrix and measurement vector are normalized to counteract biases from radiation shielding and time-varying intensities. Validation using a two-room model with internal shielding, with PHITS Monte Carlo simulation, demonstrates accurate reconstruction of dynamic sources from remote measurements. Temporal regularization enhances situational awareness by suppressing spatial aliasing: at sliding-window width (no regularization), hotspot locations fluctuate significantly, with quantitative mean absolute error fluctuations at around , whereas yields improved spatial consistency and the fluctuation quantities decrease to the range. Comparative analysis identifies as optimal in balancing accuracy and computational cost. This work establishes a more reliable pathway for dynamic hazard assessment, enabling accurate localization and intensity tracking under challenging conditions. The proposed framework provides a decision-support tool enhancing the resilience and safety of emergency management in nuclear facilities.

Establishment of neutron spectrum evaluation method for irradiation facility in equilibrium core of JRR-3 silicide fuel

Nakamura, Takemi; Ogasawara, Reira; Ushijima, Hiroki; Okada, Yuji; Yamaguchi, Atsushi; Horiguchi, Hironori; Hirane, Nobuhiko

JAEA-Technology 2026-008, 39 Pages, 2026/07

JAEA-Technology-2026-008.pdf:2.55MB

Irradiation studies targeting thermal neutrons to fast neutrons are being conducted at the JRR-3 research reactor, and to accurately evaluate the irradiation effect, it is necessary to consider the influence of the neutron spectrum. Fuels and cadmium wires used as combustible absorbers are burned by reactions with neutrons because the JRR-3 is a high-power 20MW reactor, and the fuel shuffling and replacement are performed periodically to ensure uniform burnup and long-term operation. Since it is necessary to accurately reproduce the burnup history both temporally and spatially, it is difficult to evaluate the neutron spectrum with high accuracy through computational analysis. Hence, we investigated a method that can easily and accurately evaluate neutron spectra at irradiation facility in equilibrium core of JRR-3 silicide fuel and verified the validity of the evaluation results. This method uses data of initial guess spectrum and response functions for each irradiation field calculated using MCNP code, reaction rate measured from neutron fluence monitors such as Au-Al and Ni wire to perform unfolding using SAND-II. We conducted characteristic measurements from fiscal year 2023 to 2025 and performed unfolding using actual measured values from neutron fluence monitors for seven cycles. As a result, in all cases, the C/E ratio of the reaction rate was 1.000, indicating good convergence, and the difference from the unfolding and measured neutron flux was within 0.3% for hydraulic irradiation facility HR-1, within 0.8% for pneumatic irradiation facility PN-2, and 0% for vertical irradiation facility RG-2. This suggests that the results of the unfolded spectrum are valid. The application of this method can meet a wide range of user needs, and it is expected to greatly contribute to the advancement of irradiation research with improved reliability of the JRR-3 irradiation field.

Prediction of tumor control probability in prostate cancer radiotherapy using a biophysical model incorporating cancer stem cell and hypoxia

Saga, Ryo*; Iwamori, Kenta*; Matsuya, Yusuke; Hosokawa, Yoichiro*

Computers in Biology and Medicine, 211, p.111743_1 - 111743_10, 2026/07

https://doi.org/10.1016/j.compbiomed.2026.111743

This study developed a biophysical model that integrates the characteristics of cancer stem cells (CSCs), including the side population (SP), and the oxygen enhancement effect (OER) to more accurately predict radiotherapy outcomes in prostate cancer. SP and main population (MP) cells were isolated from the DU145 prostate cancer cell line, and DNA double-strand breaks and survival were evaluated under both normoxic and hypoxic conditions (0.1% O). The obtained data were analyzed using the IMK model incorporating MP, SP, and oxygen concentration, and the predictions were compared with clinical tumor control probability (TCP) under various fractionation regimens (2, 3, and 7 Gy/Fx). As a result, the in vitro and clinical data were well reproduced by considering the MP/SP fraction, a population-independent OER, and the intratumoral hypoxic volume. Furthermore, the initial yield of DSBs was identified as a key determinant of radiosensitivity depending on cell characteristics and oxygen levels. The developed model is expected to contribute to the optimization of prostate cancer radiotherapy, including dose escalation to hypoxic tumor regions.