The recent progress in the R&D neutronics efforts spent in the EU to support the development of the HCLL and HCPB breeder blankets is presented. These efforts include neutronic design activities performed in the frame of the European DEMO reactor study, validation efforts by means of neutronics mock-up experiments using 14 MeV neutron generators, and the development of dedicated tool computatio...

Highlights are presented of recent results obtained on deuterium and hydrogen loading of palladium both in electrolytes and in the gas phase. Reproducible tritium generation has been found on palladium cathodes with deuterium loadings approaching one deuterium atom per palladium atom. Tritium generation has been observed on four out of four such highly loaded cathodes. No tritium has been obser...

Measurement of the effects of helium (from tritium decay) on the weldability of Types 304 and ITER Grade 316LN stainless steel demonstrated the inherent complexities in designing and conducting an experimental program using tritium-charged-and-aged materials to simulate the effects of irradiation-induced helium on weld behavior. Differences in microstructure, surface condition and alloy chemist...

On 2 May 1974, 479,000 Ci of tritium gas escaped from a Savannah River Plant exhaust stack. The tritium first reached the ground in a pine forested area and was partially assimilated into the ecosystem. Samples of vegetation collected and measured for a period of 70 days showed an increase in the levels of tritiated water. Cycling of the tritium retained in the forest ecosystem resulted in a hi...

Internal dosimetry models that currently drive regulatory compliance decisions assume that tritium retention kinetic behavior can be modeled by a single exponential function. This is contrary to the results of a number of modeling techniques, which indicate that while elemental tritium (HT) and tritiated water (HTO) are the most commonly released forms of tritium, organically-bound tritium (OBT...

An enzyme fraction from the green alga Chlorella pyrenoidosa that catalyzes the reversible epimerization of guanosine B’diphosphate D-mannose to guanosine 5’-diphosphate L-galactose brings about the incorporation of tritium from tritium-labeled water into the hexosyl moieties of those sugar nucleotides. The hexoses were degraded by periodate oxidation whereby the tritium was found to be equally...

The first experiments on hydrogen transfer in the thymidylate synthetase reaction (Equation 1) were reported by Friedkin (2, 3). Borohydride labeled with tritium was used to reduce folic acid to tritium-labeled tetrahydrofolate which was then treated with formaldehyde to yield the 5, lo-methylene derivative. When the latter compound was used as substrate for thymidylate synthetase (prepared fro...

Lithium zirconate is a candidate material in the design of electrochemical devices and tritium breeding blankets. Here we employ an atomistic simulation based on classical pair-wise potentials to examine defect energetics, diffusion Li-ions, solution dopants. The Li-Frenkel lowest energy process. Li-Zr anti-site cluster slightly higher than Li-Frenkel. Li-ion diffuses along c axis with activati...

In the tritium breeding blanket of nuclear fusion reactors, heat transfer behavior and thermal-mechanical response breeder pebble bed are affected by inner packing structure, which is crucial for design optimization a reliable in blanket. Thus, effect size distribution fixed wall on structure contact force poly-disperse were investigated numerical simulation. The results show that has significa...