Consideration on utilization of atmospheric dispersion models for a nuclear emergency preparedness and response

Togawa, Orihiko; Okura, Takehisa; Kimura, Masanori; Nagai, Haruyasu

JAEA-Review 2021-021, 61 Pages, 2021/11

JAEA-Review-2021-021.pdf:3.72MB

Triggered by the Fukushima Daiichi Nuclear Power Station accident, there have been a lot of arguments among various situations and levels about utilization of atmospheric dispersion models for a nuclear emergency preparedness and response. Most of these arguments, however, were alternative and extreme discussions on whether predictions by computational models could be applied or not for protective measures in a nuclear emergency, and it was hard to say that these arguments were politely conducted, based on scientific verification in an emergency response. It was known, on the other hand, that there were not a few potential users of atmospheric dispersion models and/or calculation results by the models within the Japan Atomic Energy Agency (JAEA) and outside. However, they seemed to have a lack of understanding and a misunderstanding on proper use of different kinds of atmospheric dispersion models. This report compares an outline of models and calculation method in atmospheric dispersion models for a nuclear emergency preparedness and response, with a central focus on the models which have been developed and used in the JAEA. Examples of calculations by these models are also described in the report. This report aims at contributing to future consideration and activities for potential users of atmospheric dispersion models within the JAEA and outside.

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupe091.pdf

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Interlaboratory comparison of positron annihilation lifetime measurements

Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.

Materials Science Forum, 607, p.248 - 250, 2009/00

So far no standard procedure for the positron annihilation lifetime (PAL) technique has been established. A lack of the standards has led to difficulty in ensuring the equivalency and reliability of data from different laboratories. As a first, we conducted an interlaboratory comparison of PAL measurements for metal, polymer and silica glass with agreed procedures for data recording and analysis. The PAL data recorded at different laboratories were analyzed with a single lifetime component for the metal sample and with three components for the others, respectively. Based on the results of the reported positron and ortho-positronium lifetimes, the possible sources of the uncertainties in the PAL measurements are discussed. To reduce the effect of scattered rays, a lead shield was placed between the detectors. The uncertainty was significantly decreased, signifying that placing lead shields between the detectors effectively reduced the false signals due to the scattered rays.

Progress in R&D efforts on the energy recovery linac in Japan

Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.

Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06

Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.

Highly efficient separation of actinides using porous polymer sheet with anion-exchange group

Asai, Shiho; Magara, Masaaki; Shinohara, Nobuo; Yamada, Shinsuke*; Nagai, Masanori*; Miyoshi, Kazuyoshi*; Saito, Kyoichi*

no journal, , 

A porous sheet with a diethylamino (DEA) group as anion-exchange group was prepared for achieving rapid separation of U and Pu. The epoxy group containing monomer, glycidyl methacrylate was grafted onto the surface of the porous sheet. The epoxy group of the poly-GMA graft polymer chain was converted into a DEA group. The amount of the DEA group was increased with increasing reaction time and leveled off at 3.4 mol/kg of the sheet. An iron solution as a model metal ion solution was forced to permeate through the pores of the DEA-introduced sheet (DEA sheet) at a permeation rate of 20 mL/min. The equilibrium adsorption capacity of the DEA sheet for Fe ions (FeCl) was calculated as 1.1 mol-Fe/kg-DEA sheet. This value is comparable to or higher than those of conventional anion-exchange resins. U and Pu in the sample solution were separated using the DEA sheet. Trace amounts of U (38.16 pg) and Pu (0.34 pg) were found to be successfully separated with the DEA sheet.

Highly efficient solid-phase extraction of inorganic ions using ion-exchange porous polymer disk cartridge

Asai, Shiho; Magara, Masaaki; Shinohara, Nobuo; Yamada, Shinsuke*; Nagai, Masanori*; Miyoshi, Kazuyoshi*; Saito, Kyoichi*

no journal, , 

The use of a column charged with an ion-exchange resin has been widely employed to separation of actinides. However, the use of the resin-packed column has a drawback in that a higher flow rate of the sample solution through the column results in a lower recovery. In order to overcome this drawback in the use of the conventional column, we prepared an anion-exchange cartridge charged with a diethylamino-group-containing porous disk. To evaluate the applicability, the binding efficiencies of U and Pu were determined at various flow rates. 5 mL of standard solution containing U and Pu was permeated through the anion-exchange cartridge at the flow rate raging from 0.3 to 80 mL/min. Adsorption efficiencies of U and Pu were 1.0 irrespective of the flow rate. This adsorption characteristic is advantageous over the conventional anion-exchange resin-packed column in that a higher flow rate of the sample solution, i. e., a shorter processing time of analysis, is achievable.

Estimation of measurement uncertainty for positron annihilation lifetimes at an interlaboratory comparison

Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.

no journal, , 

An interlaboratory comparison for positron annihilation lifetime measurements for pure nickel, polycarbonate (PC) and fused silica was performed. Based on the reported data of positron (for nickel) and positronium (for PC and fused silica) components, the uncertainties in the PAL measurements were estimated and their possible source was discussed.