Removal of tritium from stainless steel type 316 (1) -Effect of Water Vapor-

Tritium distribution in stainless steel type 316 exposed to tritium-containing hydrogen at various temperatures was studied. Sub-surface layer of approx. 20μm thickness enriched with tritium was observed for all samples. This layer contributes 20% to 40% to overall tritium inventory. Thermal desorption study reveals that majority of tritium released from the contaminated steel is in a form of water. Several method of decontamination, such as purge with various gases at elevated temperatures and heating with methane-air flame, were tested. Heating with flame allows removal of largest fraction of tritium inventory and in shortest period of time among the tested decontamination methods

Removal of Tritium from Stainless Steel Type 316 (2) : Effect of Water Vapor

To establish a decontamination method for stainless steel type-316 (SS-316) contaminated by tritium, desorption behavior of tritium caused by heating was examined. When tritium was exposed to a temperature at 523 K for 3 hours, tritium inventories in the SS-316 samples were in the range of 2 to 12 MBq. The tritium depth profiles obtained from BIXS measurements showed that tritium diffused to a depth of more than 70μm. Decontamination test on tritium were carried out at elevated temperatures by purging with commercial argon, argon dried by a getter and argon containing water vapor. The presence of water vapor in the argon atmosphere was found to necessary for tritium decontamination from SS-316 samples. The result suggested that an isotope exchange reaction with water vapor adsorbed on the surface plays an important role in the decontamination of tritium. It was concluded that not only tritium adsorbed on the surface but also that dissolved in the bulk can be removed by heating

WET SCRUBBER COLUMN FOR AIR DETRITIATION

This paper evaluates detritiation of air contaminated with tritium in the for

INFLUENCE ON THE TEMPERATURE FIELD FILTRATION BULKED BATCH

Improving heat transfer in thermal batch furnaces leads to fuel saving and higher energy efficiency of thermal technological processes. Thermal furnaces of machinery production often use the method of heating bulked batch consisting of a large number of small metal details. The bulked batch heating can be intensified through gas filtering in the batch.Совершенствование теплообмена в термических садочных печах приводит к экономии топлива и повышению энергетической эффективности теплотехнологических процессов. В термических печах машиностроительного производства распространен нагрев насыпных садок, образованных большим количеством мелких изделий. Интенсифицировать процесс нагрева насыпной садки можно за счет организации фильтрации газов через садку

Application of BIXS Measurement to Tritium Contaminated Materials

Depth profiles of tritium in stainless steel type 316 loaded at several different conditions at JET were analyzed by β-ray-induced X-ray spectrometry (BIXS), in order to investigate the possibilities of the measurement method. The tritium depth profiles obtained by BIXS were compared with that obtained by chemical etching and radioluminography (RLG) methods. It was found that most of tritium depth profiles near surface (up to ?2μm) obtained by BIXS were in good accordance with chemical etching and RLG methods. In the same time significant difference between BIXS and RLG was found in determination of tritium depth profiles in the sub-surface layer. The reasons for the deviations will be discussed

Research of hydraulic resistance of bulk cages of thermal furnaces

In this work was to investigate the hydraulic resistance of bulk cages of thermal furnaces in the process of filtration of combustion products through the cages. Identified the resistance coefficients of the cages for different values of porosity.В данной работе было исследовано гидравлическое сопротивление насыпных садок термических печей в процессе фильтрации продуктов сгорания через садку. Определены коэффициенты сопротивления садок при различных значениях порозности

Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM