Effects of pyrolytic carbon structure on diffusivity of tritium

Saeki, Masakatsu

doi:10.1016/0022-3115(85)90421-0

Cited by 44 publications

(13 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The deposition of carbon atoms in the form of graphite or in binding with tungsten (WC or W 2 C) on the surface of the samples [24] reduces the diffusion of hydrogen in target. For example, the diffusion coefficient of hydrogen isotopes in tungsten has a value of 10 À10 -10 À12 m 2 /s at the temperature of 650 K [25,26], while this parameter for diffusion of H in randomly oriented carbon at the same temperature is around 1 Â 10 À20 m 2 /s [27]. This large difference will have a significant effect on hydrogen isotopes behavior and retention in candidate plasma facing materials in ITER-like devices.…”

Section: Simulations Of H Ion Beams With Carbon Impurities For Iter-lmentioning

confidence: 96%

Dynamic analysis and evolution of mixed materials bombarded with multiple ions beams

Sizyuk

Hassanein

2010

Journal of Nuclear Materials

View full text Add to dashboard Cite

Section: Simulations Of H Ion Beams With Carbon Impurities For Iter-lmentioning

confidence: 96%

Dynamic analysis and evolution of mixed materials bombarded with multiple ions beams

Sizyuk

Hassanein

2010

Journal of Nuclear Materials

View full text Add to dashboard Cite

“…The value of r was calculated as 1.7 χ 10" 4 cm forPechiney Qi graphite [2]. (ii) For the sample irradiated for a short time with 3 He, the relation…”

Section: Tritium-release and -Diffusion Measurements 3 Resultsmentioning

confidence: 99%

“…In previous papers, release and diffusion behaviors of tritium in carbon materials were studied in specimens which were irradiated in a nuclear power plant or on spherical pyroly tic carbons irradiated by neutrons with 3 He [1 -3]. An anisotropic diffusion mechanism of tritium in graphite materials between the basal planes was proposed [3].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Release Enhancement of Tritium from Graphite by Addition of Hydrogen

Saeki

Masaki

1989

Radiochimica Acta

Self Cite

View full text Add to dashboard Cite

The release behavior of tritium from graphite was studied in pure He and He + H, atmosphere. The release from powdered graphite was significantly enhanced in a hydrogen environment. Apparent diffusion coefficients of tritium in graphite also became much higher in an atmosphere containing hydrogen than values obtained in pure helium atmosphere. A careful investigation of the release processes resulted in the conclusion that the most important process of tritium behavior in graphite was diffusion, but the desorption process of tritium from the surface played a significant role. The enhancement of the desorption process was controlled by atomic hydrogen.

show abstract

“…Table 3 shows the observed pre-exponential factor and the activation energy for the diffusion of tritium in graphite. 11,12) As shown in Table 3, the diffusion constants considerably differ from each other due to the different microstructure of the graphite. Furthermore, the AL-2-400 graphite has the almost same diffusion constants as AS1-500 graphite, which was used in other gas cooled reactor as a reflector; 13) thus the pre-exponential factor and activation energy of AL-2-400 graphite were used in this study.…”

Section: Tritium Diffusionmentioning

confidence: 99%

Estimation of the Tritium Behavior in the Pebble Type Gas Cooled Reactor for Hydrogen Production

Yook¹,

LEE²,

LEE³

et al. 2006

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

In Korea, a nuclear hydrogen program has been established to develop and demonstrate mass production system for hydrogen generation. The objective of this study is to establish the evaluation procedure for predicting the tritium behavior in the 300 MWth Pebble type gas cooled reactor which is the one of the candidate reactors for nuclear hydrogen development and demonstration plant. The tritium generated by the fission reaction can be leaked to the helium coolant from the coated ceramic particles and fuel elements. The annual total release rate of the tritium is estimated as 0.47% from the fuel kernel to the helium coolant by the numerical method. Tritium attributed by 6 Li existing as impurities in the reflector can be released to the helium coolant by the diffusion process and the total annual release rate of the tritium is estimated as 5.3% through the reflector to the helium coolant. Based on the Siverts' law, tritium permeation from the primary coolant to the hydrogen production system is also evaluated and the result is calculated as 76-0.23 Bq/g-H 2 with respect to the PRF (Permeation Reduction Factor=10-1000) in case of the normal operation of the 300 MWth Pebble type reactor.

show abstract

Effects of pyrolytic carbon structure on diffusivity of tritium

Cited by 44 publications

References 11 publications

Dynamic analysis and evolution of mixed materials bombarded with multiple ions beams

Dynamic analysis and evolution of mixed materials bombarded with multiple ions beams

Release Enhancement of Tritium from Graphite by Addition of Hydrogen

Estimation of the Tritium Behavior in the Pebble Type Gas Cooled Reactor for Hydrogen Production

Contact Info

Product

Resources

About