<i>g</i>-Values for γ-irradiated water as a function of temperature

Elliot, A. John; Chenier, Monique P.; Ouellette, Denis C.

doi:10.1139/v90-111

Cited by 34 publications

(13 citation statements)

References 27 publications

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“…The yield of H 2 with aqueous KBr solutions using this methodology gives a value of 0.461 molecules/100 eV, which agrees well with previous results (11). The SiC powder irradiated without water (purged with argon) gave no detectable H 2 , which indicates clean surfaces on the powders.…”

Section: H 2 Production and Gamma Irradiationsupporting

confidence: 91%

Radiolytic hydrogen generation at silicon carbide–water interfaces

Schofield

Reiff

Pimblott

et al. 2016

Journal of Nuclear Materials

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While many of the proposed uses of SiC in the nuclear industry involve systems that are assumed to be dry, almost all materials have dissociated chemisorbed water associated with their surface, which can undergo chemistry in radiation fields. Silicon carbide a-phase and b-phase nanoparticles with water were irradiated with g-rays and 5 MeV He ions followed by the determination of the production of molecular hydrogen, H 2 , and characterization of changes in the particle surface. The yields of H 2 from SiC -water slurries were always greater than expected from a simple mixture rule indicating that the presence of SiC was influencing the production of H 2 from water, probably through an energy transfer from the solid to liquid phase.Although the increase in H 2 yields was modest, a decrease in the water mass percentage led to an increase in H 2 yields, especially for very low amounts of water. Surface analysis techniques included diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), nitrogen absorption with the Brunauer -Emmett -Teller (BET) methodology for surface area determination, X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Little change in the SiC surface was observed following radiolysis except for some conversion of b-phase SiC to the a-phase with He ion radiolysis.

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Section: H 2 Production and Gamma Irradiationsupporting

confidence: 91%

Radiolytic hydrogen generation at silicon carbide–water interfaces

Schofield

Reiff

Pimblott

et al. 2016

Journal of Nuclear Materials

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“…Solubility of kerosene in water is very limited. Thus, the value obtained corresponds quite well with the published results for a neat water 45-52 nmolJ -1 [7,[25][26][27][28]. The G(H 2 ) values increase to about 85 nmolJ -1 with increasing 1-octanol concentration in the organic phase.…”

Section: Aqueous Phasesupporting

confidence: 90%

“…It is worth to note that the values obtained can be much higher for -particles irradiation. The G(H 2 ) values recorded for a neat water exposed to an electron beam or -irradiation were in the range 45-52 nmolJ -1 [7,[25][26][27][28] whereas an -particle irradiation leads to values which are twice as high, and equal to 100-115 nmolJ -1 [30]. Moreover, our investigations do not concern transfer between phases, i.e.…”

Section: Discussionmentioning

confidence: 75%

“…Moreover, there are substantial differences in G(H 2 ) values of aqueous systems obtained by different type of radiation. For instance, G(H 2 ) in water exposed to an electron beam or -irradiation were in the range 45-52 nmolJ -1 [7,[25][26][27][28] whereas an -particle irradiation leads to higher than twice values 100-115 nmolJ -1 [30]. Thus, further investigations are necessary.…”

Section: Aqueous Phasementioning

confidence: 99%

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Electron beam irradiation of r-SANEX and i-SANEX solvent extraction systems: analysis of gaseous products

Szreder

Kocia

2015

Nukleonika

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1-Octanol/kerosene mixtures and water contacted with organic solvents were used as model solutions for r-SANEX and i-SANEX extractions systems. Investigations aimed on a quantitative evaluation of gaseous products generated in these systems under exposure to an electron beam irradiation. Influence of O2, HNO3 and the presence of model ligands and complexes on the radiation chemical yields was studied. Relatively high G(H2) values (up to 420 nmol·J-1) for the organic phase compromise the safety issues of the extraction process and should be considered on the stage of extraction apparatus design. Based on the obtained results gaseous hydrocarbons seem to have negligible impact on safety issue. The upper limit of G(H2) values in water contacted with organic phase was established to be 85 nmol·J-1. This value is relatively low, however, the literature data indicate that G(H2) values measured in aqueous solutions are over twice higher for α-particles irradiation than for electron beam or γ-irradiation. Thus, further investigations of these systems are necessary.

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“…The H 2 generation G-values for neutrons was 1.7-2.3 when specimens contained a lot of water. This value is large: 2-5× larger than the value for hydrogen generation from bulk water by gamma radiation alone (G=0.45) or neutron (G=1.0) (Elliot et al 1990, Kasten 1991, Joseph et al 2008, Butarbutar et al 2014. This value can be 0.04 when there was almost no free water.…”

Section: It-a1mentioning

confidence: 81%

Development of Soundness Assessment Procedure for Concrete Members Affected by Neutron and Gamma-Ray Irradiation

Maruyama

Kontani

Takizawa

et al. 2017

ACT

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In 2008, Nuclear and Industrial Safety Agency (NISA) (currently integrated to the Nuclear Regulatory Authority) launched a project to develop a soundness assessment method for concrete members subject to a radiation environment. Presently, the soundness of concrete members subject to radiation is evaluated based on whether the predicted fast neutron fluence and gamma-ray dose values are lower than specific reference values in Japan, which are 1×10 20 n/cm 2 and 2×10 5 kGy, respectively. These reference values were determined based on report by Hilsdorf et al. This project begins by reviewing Hilsdorf et al.'s report, and we find that the scientific evidence for the current reference values is weak. We thus conclude that new experimental research is required to assess the current reference values and to propose a new alternative soundness assessment procedure if needed. We quantitatively evaluated the influence of neutrons, gammarays, and the resultant heating and drying processes on the strength of concrete as well as their underlying mechanisms. The irradiation experiments confirmed the degradation mechanism of concrete due to neutron irradiation. The main reason for this degradation is the metamictization of rock-forming minerals, which, in turn, leads to aggregate expansion. Due to aggregate expansion, cracks around aggregates form, which reduce the compressive strength and Young's modulus of concrete. Among the rock-forming minerals, α-quartz is the most sensitive to neutron radiation.60 Co gamma-ray irradiation experiments demonstrated that concrete strength increased as the gamma-ray dose and gammaray flux does not have a dose-rate impact on the first radiolysis of evaporable water in cement paste within the present study. The effect of gamma-ray irradiation on the properties of concrete is equivalent to that of heating and drying. Concrete strength alteration due to heating and drying is attributed to the colloidal and porous nature of hardened cement paste and crack formation around the aggregate due to a mismatch in the volume changes of the mortar and aggregate. In addition, a numerical analysis code called DEVICE (Damage EValuation for Irradiated ConcretE) is developed to harness knowledge obtained from concrete samples to predict the distribution of the physical properties in concrete members and their changes over time. From these fundamental studies, we propose a new soundness assessment procedure for concrete members subject to radiation. We also recommend a new radiation-induced strength-degradation reference value of 1×10 19 n/cm 2 for fast neutron.

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g-Values for γ-irradiated water as a function of temperature

Cited by 34 publications

References 27 publications

Radiolytic hydrogen generation at silicon carbide–water interfaces

Radiolytic hydrogen generation at silicon carbide–water interfaces

Electron beam irradiation of r-SANEX and i-SANEX solvent extraction systems: analysis of gaseous products

Development of Soundness Assessment Procedure for Concrete Members Affected by Neutron and Gamma-Ray Irradiation

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