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.

Overview of Ukraine's denuclearization process

Tazaki, Makiko; Kimura, Takashi

Enerugi Rebyu, 42(9), p.62 - 63, 2022/08

no abstracts in English

Proceeding of the Workshop on the Results of the Cooperative Research between JAERI and CHESCIR Concerning the Study on Assessment and Analysis of Environmental Radiological Consequences and Verification of an Assessment System; November 16-17, 1999, Tokyo

Amano, Hikaru; Saito, Kimiaki

JAERI-Conf 2000-016, 205 Pages, 2001/03

JAERI-Conf-2000-016.pdf:19.43MB

no abstracts in English

Mechanical integrity of floor liner in secondary heat transport system cells of Monju

; ; Ueno, Fumiyoshi; ; ; ;

JNC TN2400 2000-005, 103 Pages, 2000/12

JNC-TN2400-2000-005.pdf:3.98MB

Inelastic analyses of the floor liner subjected to thermal loading due to sodium leakage and combustion were carried out, considering thinning of the liner plate due to molten salt type corrosion. Because the inelastic strain obtained by the analyses stayed below the ductility limit of the material, mechanical integrity, i.e., there exist no through-wall crack on the floor liner, was confirmed. Partial structural model tests were conducted, with a band of local thinning of the liner plate. Displacements were controlled to give specimens much larger strains than those obtained by the inelastic analyses above. No through-wall crack was observed by these tests. Mechanical integrity of the floor liner was confirmed by these results of the inelastic analyses and the partial structural model tests.

"Local solid element modeling" for detailed analyses of floor liner

Tsukimori, Kazuyuki

JNC TN9400 2000-086, 103 Pages, 2000/08

JNC-TN9400-2000-086.pdf:3.67MB

ln order to evaluate the integrity of the floor liner of "MONJU" at sodium leakage accident, nonlinear finite element analyses have been conducted considering the effect of thinning of the liner due to molten salt type corrosion. Modeling by shell elements is appropriate since liner is composed of thin plates, however, it is difficult to deal with the very local strain behaviors. 0n the other hand, modeling by solid elements makes the numerical calculation impractical. If we extract the small part of the liner which includes local discontinuities, it is possible to evaluate local strain behaviors practically by using the solid element analysis model of the part. To realize this approach, the method to generate all the boundary displacements of the part model from the shell element analysis result of total structure is needed. The aims of this study are to develop the method to deal with the incompatibility between shell and solid elements at part model boundary, and to build numerical analysis circumstances including this method to make the detailed nonlinear finite element analyses of the floor liner of "MONJU" possible. Summary of the results is shown below, (1)The problem of the incompatibility between shell and solid elements was solved by introducing weighting function at 'T' and 'L' type corners and the interpolation function of 4-node rectangular plate bending element at the connection between liner plate and frame. (2)Software system was developed by using 'FINAS' and verified. (3)This approach was applied to one of the cases of the floor liner analyses of "MONJU" at sodium leakage accident. The analysis result showed that three-dimensional local strain behavior could be evaluated directly. ln addition, it was confirmed that the result by shell element analysis was conservative in evaluation of strain compared with that by solid element analysis in this case.

Magnetic field modification of 18GHz electron cyclotron resonance ion source at Japan Atomic Energy Research Institue

Yokota, Wataru; Saito, Yuichi; Nara, Takayuki; Ishii, Yasuyuki; Arakawa, Kazuo

Review of Scientific Instruments, 71(2), p.906 - 908, 2000/02

https://doi.org/10.1063/1.1150328

no abstracts in English

Corrosion bihavior of carbon steel in high-temperature sodium compounds; Recommended equation for corrosion rate of the carbon steel in sodium compounds (NaO-NaOH System)

Yoshida, Eiichi; Aoto, Kazumi; Hirakawa, Yasushi;

JNC TN9400 2000-024, 42 Pages, 1999/10

JNC-TN9400-2000-024.pdf:1.63MB

For the purpose of improving the reliability of evaluation, the corrosion rate equation of the carbon steel SM400B (JIS G3106) in the high-temperature sodium compounds (NaOH-Na0 system) was revised. ln this revision, the data acquired after 1997 was used. Based on the experimental results, the evaluation was made to be an approach to the following; (1)Metal loss of carbon steel in NaOH-Na0 system was evaluated as increases in exposure to the time, which is linear rate law. (2)There were no significant effects of the experiment atmosphere and mixing speed of the reagent on corrosion rate. (3)The concentration of Na0 in sodium compound is considered for the evaluation. The concentration under experiment is made to be the over concentration necessary for maintaining the dominant reaction between Fe and Na20. As a result of the evaluation, the additional data are 67 points. The data for the revision of the evaluation equation became the total of 105 points, when existing data of 38 points were added. The statistical evaluation of 105 points was carried out, and following recommended equation was obtained. C = C exp(-Q/RT) Where; C : Corrosion rate, mm/h C : Material constant Q : Apparent activation energy, cal/mol R : Gas constant, 1.986 cal/mol K T ; Absolute temperature, K Q = 9.61 kcal/mol C = 148.29 (average), 262.11 (99% UCL), 83.90 (99% LCL)

High-temperature strength test of the liner material (II); High-temperature tensile and creep property of SM400B welded joint material

; Aoto, Kazumi;

PNC TN9450 97-012, 75 Pages, 1996/11

PNC-TN9450-97-012.pdf:25.58MB

This report described the results of tensile and creep tests under a high temperature with the welded joints of liner plate (SM400B) used in SHTS cells of leaked sodium storage system of "NONJU plant". Results obtained are summarized as follows. (1)Foundmental high temperature strength characteristics data of the welded Joints were acquired. (2)There is no effect of heat treatment and cut-out direction on tensile strength and rupture elongation of liner plate. (3)The rupture ductility (rupture elongation and reduction of area) is lower than one of the base metal. Especially, rapidly droped in the temperature over 800 C. (4)The creep strength of welded joint is almost same as one of the based metal. It will be estimated the effect of change of the micro-structure on the ductility. (5)Generally speaking, two phases of phase and phase intermingled exist under about 800C, and phases transform to the phase under about 900C over Ac3 transformation point. Then the grain boundary in HAZ, begin to grow, and the intergranular failure appears in over 900C. The results will be applied to evaluate the stractural integrity of SHTS cells of leaked sodium storage system of "MONJU plant". (SHTS ; Secondary Heat Transfer System)

FEL experiment with a focusing wiggler

*; Sakamoto, Keishi; *; Musyoki, S.*; *; Ishizuka, H.*; Nagashima, Takashi; Kawasaki, S.*;

JAERI-M 92-109, 68 Pages, 1992/08

JAERI-M-92-109.pdf:1.94MB

no abstracts in English

Development of ceramic liner for FBR building

Himeno, Yoshiaki; Morikawa, Satoshi; Kawada, Koji; Yorita, E.*; Fujiwara, T.*; Kaneshige, T.*; Irie, S.*

PNC TN9410 91-092, 11 Pages, 1991/01

PNC-TN9410-91-092.pdf:1.53MB

To develop a ceramic liner, a selection test of materials, an improvement test of selected material, and a feasibility test of the liner have been conducted.in the selection test, fifty commercially available high temperature cement and ceramics were subjected to thermal shock test (tst), sodium exposure test(set), and sodium flame exposure test (sfet). From test results, alumina/silicon-carbide (AlO-sic)mixture base castable refractory was selected in consideration of material cost, and material availability for a simpler liner construction in the buildings. The selected material was subjected to the improvement test. from the test, proper weight fractions of additives such as alumina cement and silica were determined. Drying conditions were also determined. Finally, a sodium burning pan made of concrete whose inner surfaces were covered with the improved AlO-sic base castable refractory was fabricated and was used for a sodium burning test.