Evaluation report for sludge measurement by nondestructive assay (Plutonium Scrap Multiplicity Counter)(Joint research)

Tanigawa, Masafumi; Seya, Kazuhito*; Asakawa, Naoya*; Hayashi, Hiroyuki*; Horigome, Kazushi; Mukai, Yasunobu; Kitao, Takahiko; Nakamura, Hironobu; Henzlova, D.*; Swinhoe, M. T.*; et al.

JAEA-Technology 2024-014, 63 Pages, 2025/02

JAEA-Technology-2024-014.pdf:3.02MB

The liquid waste treatment process generated sludge items at the plutonium conversion development facility. They are highly heterogeneous and contain large amounts of impurities (Na, Fe, Ni etc.). Therefore, the sludge items have very large sampling uncertainty and so the total measurement uncertainty is very large (approximately 24%). The plutonium scrap multiplicity counter (PSMC) measurement technique for sludge items was developed by joint research between the Japan Atomic Energy Agency (JAEA) and Los Alamos National Laboratory (LANL). The technical validity for sludge items using the PSMC was evaluated using various types of sample measurements and Monte Carlo N-Particle transport code calculations. The PSMC measurement parameters were found to be valid for use with sludge items and the validity of multiplicity analysis was confirmed and demonstrated through comparisons with standard MOX powder and a standard sludge. As a result, the PSMC measurement values were shown to be consistent and reasonable and the large amount of impurity (Fe, Ni etc.) did not impact the results. Therefore, the measurement uncertainty of the improved nuclear material accountancy (NMA) procedure by combined PSMC and high-resolution gamma spectrometry was shown to be 6.5%. In addition, an acceptance test was conducted using PSMC/HRGS and IAEA benchmark equipment. Measured Pu mass by both equipment agrees within the measurement uncertainty of each method, and so the validity for Pu mass measurement by PSMC/HRGS was confirmed. The above results confirm the applicability of PSMC/HRGS as an additional NMA method for sludge and a newly designed NDA procedure based on this study is applied to sludge for NMA in PCDF.

Research on factor analysis and technical process for achieving denuclearization; Investigation of DPRK' case

Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Suda, Kazunori

JAEA-Review 2024-043, 91 Pages, 2024/12

JAEA-Review-2024-043.pdf:2.68MB

As part of the "Research on Factor Analysis and Technical Processes for Denuclearization," this report examines the DPRK's nuclear development and denuclearization (through 2018) and analyzes it from the perspective of eight denuclearization factors, as week as discusses the lessons for denuclearization. Since the Korean War, DPRK has pursued nuclear weapon development for reasons such as ensuring national security, maintaining and strengthening the Kim regime and for bargaining chip in diplomatic negotiations and has come to possess nuclear weapons. In addition to economic sanctions imposed by the UN Security Council and the United States, the international community has tried to promote the denuclearization of DPRK by forming international frameworks, but none of them had succeeded. Denuclearization of DPRK will not be easy and even getting DPRK to the diplomatic table will be difficult. However, in order to realize CVID in the future, the international community must insist on the need for DPRK to comply with international nonproliferation norms, cooperate to ensure that sanctions by the five nuclear weapon states are implemented without creating "loopholes," and, based on the principle of "promise for promise, action for action" presented at the six-party talks, respond immediately to DPRK's denuclearization measures. It will be necessary to continue efforts to implement sanctions in a step-by-step manner, with credible verification.

Applicability of passive neutron non-destructive assay technique for Pu quantification in advanced fast fuels

Eguchi, Aya*; Sagara, Hiroshi*; Mitsuboshi, Natsumi; Nagatani, Taketeru

Dai-45-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 2 Pages, 2024/11

Advanced fast reactor fuel contains minor actinides and fission products such as lanthanides in addition to uranium and plutonium, and it is supposed to include neutrons and gamma-ray originating from sources other than nuclear materials even in its fresh status. The purpose of this study is to evaluate the applicability of passive neutron nondestructive measurement techniques using coincidence accounting, Differential Die Away Self Interrogation assay technique to the quantification of plutonium in advanced fast reactor fuels. This paper shows the results of Pu-240 effective mass calculation in the Pu neutron sources in the simple simulation design by neutron coincidence accounting for the benchmark of simulation code.

Opinions of experts on protection of nuclear facilities from armed attacks by state actors

Tazaki, Makiko

Dai-45-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2024/11

no abstracts in English

Development of a nondestructive assay technique using a laser-driven neutron source

Koizumi, Mitsuo; Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Arikawa, Yasunobu*; Abe, Yuki*; Wei, T.*; Yogo, Akifumi*; et al.

Dai-45-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2024/11

Demonstration of shape analysis of neutron resonance transmission spectrum measured with a laser-driven neutron source

Koizumi, Mitsuo; Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Arikawa, Yasunobu*; Abe, Yuki*; Lan, Z.*; Wei, T.*; et al.

Scientific Reports (Internet), 14, p.21916_1 - 21916_9, 2024/09

https://doi.org/10.1038/s41598-024-72836-8

Single-shot laser-driven neutron resonance spectroscopy for temperature profiling

Lan, Z.*; Arikawa, Yasunobu*; Mirfayzi, S. R.*; Morace, A.*; Hayakawa, Takehito*; Sato, Hirotaka*; Kamiyama, Takashi*; Wei, T.*; Tatsumi, Yuta*; Koizumi, Mitsuo; et al.

Nature Communications (Internet), 15, p.5365_1 - 5365_7, 2024/07

https://doi.org/10.1038/s41467-024-49142-y

Preliminary status and results of the JAEA/ISCN fission signature assay instrument for delayed gamma-ray spectrometry nuclear safeguards

Rodriguez, D.; Akamatsu, Shunsuke*; Rossi, F.; Suzuki, Satoshi*; Takahashi, Tone

Proceedings of 65th Annual Meeting of the Institute of Nuclear Materials Management (Internet), 9 Pages, 2024/07

Implementation of a Mini-slab-based neutron detector system to increase the efficiency of safeguards verification of hold-up at MOX fuel fabrication facilities in Japan

Kyffin, J.*; Dia, A.*; Nkosi, G.*; Nizhnik, V.*; Hayashi, Akihiko; Nagatani, Taketeru

Proceedings of 65th Annual Meeting of the Institute of Nuclear Materials Management (Internet), 8 Pages, 2024/07

Research on factor analysis and technical process for achieving denuclearization; Denuclearization of Former Soviet Union (Belarus, Kazakhstan and Ukraine)

Tazaki, Makiko; Kimura, Takashi; Shimizu, Ryo; Nakatani, Takayoshi; Suda, Kazunori

JAEA-Review 2023-042, 121 Pages, 2024/03

JAEA-Review-2023-042.pdf:3.01MB

As part of the "Research on Factor Analysis and Technical Processes for Achieving Denuclearization", we investigated denuclearization cases in three former Soviet Union countries, namely Belarus, Kazakhstan, and Ukraine, and analyzed the cases by eight denuclearization factors. We then considered the characteristics and lessons learned from such denuclearization. The denuclearization processes of the three countries differed from country to country, and Ukraine's denuclearization process in particular went through many twists and turns. However, the common factor was that all nuclear-weapon states provided security assurances to the three countries and as a result, they transferred strategic nuclear weapons to Russia and joined the Nuclear Non-proliferation Treaty (NPT) as non-nuclear weapon states. Such decision was partly made possible by the economic and physical assistance provided by the United States and Russia for denuclearization. Furthermore, one of the characteristics of the denuclearization of the three countries is the US's skillful denuclearization strategy toward the three countries. The United States supported the claims that the three countries, like Russia, were parties to the First Strategic Arms Reduction Treaty (START-I), and ultimately allowed them to transfer strategic nuclear warheads to Russia within the framework of START-I and the subsequently achieved the disposal of the warheads in Russia. Furthermore, as a lesson from the denuclearization of the three countries, providing security assurance to denuclearized countries is a strong incentive for denuclearization. However, considering Russia's annexation of Crimea in 2014 and military invasion of Ukraine in February 2022, countries which are required denuclearization will seek stronger security guarantees from nuclear-weapon states. Another lesson is that it is necessary to have a strong presidential initiative the countries concerned.