Data report of ROSA/LSTF experiment TR-LF-15; Accident management actions during station blackout transient with pump seal LOCA

Takeda, Takeshi

JAEA-Data/Code 2023-012, 75 Pages, 2023/10

JAEA-Data-Code-2023-012.pdf:4.45MB

An experiment denoted as TR-LF-15 was conducted on June 11, 2014 using the Large Scale Test Facility (LSTF) in the Rig of Safety Assessment-V (ROSA-V) Program. The ROSA/LSTF experiment TR-LF-15 simulated accident management (AM) actions during a station blackout transient with TMLB' scenario with pump seal loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). This scenario is featured by loss of auxiliary feedwater functions. The pump seal LOCA was simulated by a 0.1% cold leg break. The test assumptions included total failure of both high pressure injection system and low pressure injection system of emergency core cooling system (ECCS). Also, it was presumed non-condensable gas (nitrogen gas) inflow to the primary system from accumulator (ACC) tanks of ECCS. When steam generator (SG) secondary-side collapsed liquid level dropped to a certain low liquid level, the primary pressure turned to rise. After the SG secondary-side became voided, the safety valve of a pressurizer cyclically opened which led to loss of primary coolant. Core uncovery thus took place owing to core boil-off at high pressure. When an increase of 10 K was confirmed in cladding surface temperature of simulated fuel rods, SG secondary-side depressurization was started as the first AM action. At that time, the safety valves in both SGs were fully opened. Primary depressurization was initiated by completely opening the pressurizer safety valve as the second AM action with some delay after the first AM action onset. When the SG secondary-side pressure lowered to 1.0 MPa following the first AM action, water was injected into the secondary-side of both SGs via feedwater lines with low-head pumps as the third AM action. A reduction in the primary pressure was accelerated because the heat removal from the SG secondary-side system resumed shortly after the third AM action initiation.

Pole position of measured in reactions

Aikawa, Shu*; Hashimoto, Tadashi; Tanida, Kiyoshi; 73 of others*

Physics Letters B, 837, p.137637_1 - 137637_8, 2023/02

https://doi.org/10.1016/j.physletb.2022.137637

Population of nuclides with Z98 in multi-nucleon transfer reactions of Ca+Cm

Devaraja, H. M.*; Heinz, S.*; Beliuskina, O.*; Hofmann, S.*; Hornung, C.*; Mnzenberg, G.*; Ackermann, D.*; Gupta, M.*; Gambhir, Y. K.*; Henderson, R. A.*; et al.

European Physical Journal A, 55(2), p.25_1 - 25_9, 2019/02

https://doi.org/10.1140/epja/i2019-12696-3

Data report of ROSA/LSTF experiment SB-SG-10; Recovery actions from multiple steam generator tube rupture accident

Takeda, Takeshi

JAEA-Data/Code 2018-004, 64 Pages, 2018/03

JAEA-Data-Code-2018-004.pdf:3.33MB

Experiment SB-SG-10 was conducted on November 17, 1992 using LSTF. Experiment simulated recovery actions from multiple steam generator (SG) tube rupture accident in PWR. Primary pressure was kept higher than broken SG secondary-side pressure due to coolant injection from high pressure injection (HPI) system into cold and hot legs even after start of full opening of intact SG relief valve (RV). Full opening of power-operated relief valve (PORV) in pressurizer (PZR) resulted in pressure equalization between primary and broken SG systems as well as PZR liquid level recovery. Broken SG RV opened once after start of intact SG RV full opening. Core was filled with saturated or subcooled liquid through experiment. Significant natural circulation prevailed in intact loop after start of intact SG RV full opening. Significant thermal stratification appeared in hot legs especially during time period of HPI coolant injection into hot legs.

Mineralogical, physical and chemical investigation of compacted Kunigel V1 bentonite in contact with a steel heater in the ABM test package 1 experiment, sp Laboratory, Sweden

Sasamoto, Hiroshi; Isogai, Takeshi*; Kikuchi, Hirohito*; Sato, Hisao*; Svensson, D.*

Clay Minerals, 52(1), p.127 - 141, 2017/03

https://doi.org/10.1180/claymin.2017.052.1.09

Compacted bentonite has been considered as a candidate of engineering barrier material in many countries for the safe disposal of high-level radioactive waste. SKB set up an in situ experiment (named ABM project) to compare the stability of different bentonites under the conditions exposed to an iron source and elevated temperature (up to 130C as maximum) at the sp Hard Rock Laboratory, Sweden. Results for the Japanese bentonite (Kunigel V1) are summarized in the present paper. Mineralogical investigation using X-ray diffraction (XRD) and X-ray spectroscopy (SEM-EDX) suggested that no indication of smectite transformation or newly formed clay phases were observed. However, a distinct change of exchangeable cations of smectite was indicated (i.e., from Na type to Fe type) in the bentonite at the vicinity of the steel heater. Physical investigation by measurements of hydraulic conductivity and swelling property suggested that no significant change occur in the bentonite even at the vicinity of the steel heater. Such results might be considered due to the limited portion affected by the iron-bentonite interactions and partially occurred ion exchange reactions. Chemical investigation based on the measurements of methylane blue (MB), cation exchange capacity (CEC) and exchangeable cations showed that the lateral distribution for these parameters were basically constant without the significant gradient.

Chemical reaction of lithium with room temperature atmosphere of various humidities

Furukawa, Tomohiro; Hirakawa, Yasushi; Kondo, Hiroo; Kanemura, Takuji; Wakai, Eiichi

Fusion Engineering and Design, 98-99, p.2138 - 2141, 2015/10

BB2014-0426.pdf:0.49MB

https://doi.org/10.1016/j.fusengdes.2014.11.019

In the International Fusion Materials Irradiation Facility (IFMIF), a back plate of the target assembly will be exchanged during the in-service period. During the works, the lithium components will react chemically with the surrounding atmosphere. In this research, the chemical reaction of lithium in air, oxygen and nitrogen containing variable humidity at room temperature has been investigated to estimate the chemical reaction during the exchange works.

Possible oxygen reduction reactions for graphene edges from first principles

Ikeda, Takashi; Hou, Z.*; Chai, G.-L.*; Terakura, Kiyoyuki*

Journal of Physical Chemistry C, 118(31), p.17616 - 17625, 2014/08

https://doi.org/10.1021/jp5038365

N-doped carbon-based nanomaterials are attracting a great interest as promising Pt-free electrode catalysts for polymer electrolyte fuel cells (PEFCs). In this computational study, we demonstrate that N-doped graphene edges can exhibit enhanced catalytic activity toward oxygen reduction reactions by controlling their electron-donating and -withdrawing abilities, and basicity, resulting in higher selectivity of 4e reduction via inner and outer sphere electron transfer at edges in acidic conditions, respectively. Our simulations also show that 2e reduction occurs selectively in the presence of pyridinic N next to carbonyl O at zigzag edges. This study thus rationalizes the roles of doped N in graphenelike materials for oxygen reduction reactions.

Methods for tritium production rate measurement in design-oriented blanket experiments

Verzilov, Y. M.; Ochiai, Kentaro; Nishitani, Takeo

Fusion Science and Technology, 48(1), p.650 - 653, 2005/07

https://doi.org/10.13182/FST05-A1009

no abstracts in English

Characteristics of a low energy and high flux compact plasma source and preliminary results in studying surface modification of tungsten irradiated by the source

Luo, G.; Shu, Wataru; Nakamura, Hirofumi; Ohira, Shigeru; Hayashi, Takumi; Nishi, Masataka

JAERI-Tech 2004-031, 27 Pages, 2004/03

JAERI-Tech-2004-031.pdf:2.88MB

A plasma source has been constructed for investigating plasma-surface interactions in a tokamak. It is a compact device with a total length less than 1 m, compared to other existing facilities in the world. However, it can provide with stable plasma beams of low energy (100 eV) and high flux (10 /m/s), close to the predicted edge plasma conditions near the ITER divertor. This report presents mainly its configuration and its characteristics, including influence of filament, arc discharge, magnetic field, bias voltage parameters, and so on, on plasma beam being delivered towards the sample. Also shown are the results of preliminary experiments of blister formation on tungsten samples irradiated by a deuterium plasma beam generated with the source.

Neutron data storage and retrieval system NESTOR2

Nakagawa, Tsuneo

JAERI-Data/Code 2003-016, 89 Pages, 2003/11

JAERI-Data-Code-2003-016.pdf:3.0MB

The data storage and retrieval system for neutron-induced reaction data NESTOR2 was developed. NESTOR2 was written in Fortran77, and can be used on workstations with UNIX and personal computers with Windows. Input data to NESTOR2 are those in EXFOR which are compiled and maintained under the international collaboration for nuclear data. By using the retrieval code, they can obtain lists of data index, numerical data and comment information and data files of numerical data. The present report explains the system and provides a user's manual of NESTOR2.