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Strict control of tritium migration is an essential requirement for every blanket concept in a fusion reactor. Tritium permeation barriers (TPBs) have been developed in particular for liquid lithium-lead blankets using ceramic coatings; however, recent DEMO reactor design activities initiate an argument that a TPB is necessary also in solid breeder blankets. The previous studies revealed that reduced activation ferritic/martensitic (RAFM) steels and ceramic coatings reacted with solid breeder lithium ceramics under the blanket conditions, indicating the reactivity of solid breeders and its effect on tritium permeation should be taken into consideration. Moreover, not only the RAFM steel but the TPB will be exposed to pressurized water in a case where the TPB is applied to the cooling side. In this study, compatibility tests with pressurized water and lithium ceramic pebbles have been carried out for the investigation of the chemical stability of the TPB coatings and the effect on hydrogen isotope permeation in the Water Cooled Ceramic Breeder blanket., The 20th International Conference on Fusion Reactor Materials (ICFRM-20)

Beryllium intermetallic compounds (beryllides) such as Be12Ti and Be12V are the most promising advanced neutron multipliers in demonstration (DEMO) power reactors because of their low swelling and high stability at high temperatures. In this work, beryllides pebbles with binary and ternary compositions were successfully fabricated by combining plasma sintering and rotating electrode methods. After 3 keV D2+ ions were implanted to the beryllides pebbles, the deuterium desorption and retention properties were investigated by thermal desorption spectroscopy to investigate hydrogen desorption and retention of these materials for fusion application. The desorption properties and retention of hydrogen isotopes (deuterium) using the newly developed beryllide pebbles indicated that the beryllide pebbles exhibited better deuterium desorption properties, such as lower starting-up temperature, total retention, and activation energy for deuterium desorption than beryllium.

The thermomechanical behavior of titanium beryllide pebble beds was investigated experimentally at ambient temperature in helium. The pebbles consist of a mixture of TiBe12 and Ti2Be17 titanate beryllide phases and a small residual amount of Be phase, denominated as Be-7.7Ti. For purposes of comparison, experiments in air and helium atmosphere were also conducted with Be, Al2O3 and orthosilicate pebble beds. The pebble beds were compressed uniaxially up to 4.5 MPa; the effective thermal conductivity was measured using the hot wire technique. The stress-strain curves do not differ significantly for the different granular materials in contrast to the effective thermal conductivity k. Whereas for Be pebble beds k increases strongly with increasing stress (about 600 % for the uniaxial stress of 4 MPa), the increase is much smaller for the other granular materials (about 60 % for Be-7.7Ti at 4 MPa). The main reason for the large differences is the much lower thermal conductivity of the solid materials. Another influence exists because the other materials are mechanically harder resulting in smaller contact surfaces. As long as the thermal conductivity of other beryllide materials is significantly lower than that of Be, comparable results are expected as for Be-7.7Ti. It is argued that similar results are expected for single phase TiBe12 pebble beds. Because of the harder behavior compared to Be-7.7Ti pebbles, the effective thermal conductivity might be slightly smaller. Although the above reasonings suggest that a phase mixture can be used instead of the single phase TiBe12, this issue has to be investigated in more detail.

Beryllium (Be) and its alloys are one of the most important elements in mineral resources for fusion blankets and are also one of the thirty rare metal elements. Be with more than 500 tons is necessary, depending on the blanket design of the demonstration power plant (DEMO) of fusion reactors. However, Be market in the world is so rare situation compared with other metal markets. Approximately 90 percent of the entire amount of Be production in the world is produced in the United States. Then, the gross production of Be is only 300 tons per year. Because most of Be mines are currently in rest or out of production despite the presence of a lot of Be mines, an increase of Be production associated with new Be mine development is necessary. In parallel with the mine development, furthermore, the innovation of a new Be refinement technique in economical and safe is essential. Because the conventional process has huge issues such as high-temperatures treatment of approximately 2,000 °C and complicated process including powdery Be handling with a high risk for safety. Accordingly, the strategic resource procurement and an innovative refinement process should be established for the stable securing of Be resource as well as the recycling of spent materials, and these are indispensable for an early realization of fusion reactors. An innovative refinement process of Be from ores has been successfully established by treatment combined with microwave heating and chemical reaction. This innovative process has a low temperature treatment of less than 250 °C with a wet process, which has advantages with a higher energy-saving, safer and more simplified process than the conventional process. In this study, it was clarified by experimental results that this process is also so effective compared with the conventional process., 31st Symposium on Fusion Technology (SOFT2020)

The purpose of this study was to evaluate the mechanical properties of beryllide (Be12Ti) fabricated by a plasma sintering method to provide important properties data for the material database for DEMO design. Single-phase Be12Ti powders were successfully fabricated by the homogenization treatment. Plasma sintering was performed using the homogenized powders at various temperatures to investigate the effect of sintering temperature on the density and microhardness of Be12Ti. The sintering density of Be12Ti increased with an increase in sintering temperature from 900 to 1000 °C and then saturated above 1000 °C. The sintering density was almost equal to the theoretical density. The variation in Vickers microhardness as a function of temperature was similar to that of sintering density. The fracture toughness values of Be12Ti calculated using Anstis, Evans and Charles, Tanaka equations, and Japanese industrial standards (JIS) R1607 criteria were approximately 2.16, 2.07, 2.00, and 2.43 MPa·m0.5, respectively.

We investigated the effects of nutrient intake timing on glycogen accumulation and its related signals in skeletal muscle after an exercise that did not induce large glycogen depletion. Male ICR mice ran on a treadmill at 25 m/min for 60 min under a fed condition. Mice were orally administered a solution containing 1.2 mg/g carbohydrate and 0.4 mg/g protein or water either immediately (early nutrient, EN) or 180 min (late nutrient, LN) after the exercise. Tissues were harvested at 30 min after the oral administration. No significant difference in blood glucose or plasma insulin concentrations was found between the EN and LN groups. The plantaris muscle glycogen concentration was significantly (p &lt, 0.05) higher in the EN group&mdash, but not in the LN group&mdash, compared to the respective time-matched control group. Akt Ser473 phosphorylation was significantly higher in the EN group than in the time-matched control group (p &lt, 0.01), while LN had no effect. Positive main effects of time were found for the phosphorylations in Akt substrate of 160 kDa (AS160) Thr642 (p &lt, 0.05), 5'-AMP-activated protein kinase (AMPK) Thr172 (p &lt, 0.01), and acetyl-CoA carboxylase Ser79 (p &lt, 0.01), however, no effect of nutrient intake was found for these. We showed that delayed nutrient intake could not increase muscle glycogen after endurance exercise which did not induce large glycogen depletion. The results also suggest that post-exercise muscle glycogen accumulation after nutrient intake might be partly influenced by Akt activation. Meanwhile, increased AS160 and AMPK activation by post-exercise fasting might not lead to glycogen accumulation.

The thermomechanical behavior of titanium beryllide pebble beds was investigated experimentally at ambient temperature in helium. The pebbles consist of a mixture of TiBe12 and Ti2Be17 titanate beryllide phases and a small residual amount of Be phase, denominated as Be-7.7Ti. For purposes of comparison, experiments in air and helium atmosphere were also conducted with Be, Al2O3 and orthosilicate pebble beds. The pebble beds were compressed uniaxially up to 4.5 MPa; the effective thermal conductivity was measured using the hot wire technique. The stress-strain curves do not differ significantly for the different granular materials in contrast to the effective thermal conductivity k. Whereas for Be pebble beds k increases strongly with increasing stress (about 600 % for the uniaxial stress of 4 MPa), the increase is much smaller for the other granular materials (about 60 % for Be-7.7Ti at 4 MPa). The main reason for the large differences is the much lower thermal conductivity of the solid materials. Another influence exists because the other materials are mechanically harder resulting in smaller contact surfaces. As long as the thermal conductivity of other beryllide materials is significantly lower than that of Be, comparable results are expected as for Be-7.7Ti. It is argued that similar results are expected for single phase TiBe12 pebble beds. Because of the harder behavior compared to Be-7.7Ti pebbles, the effective thermal conductivity might be slightly smaller. Although the above reasonings suggest that a phase mixture can be used instead of the single phase TiBe12, this issue has to be investigated in more detail.

Beryllium intermetallic compounds (beryllides) are known as promising materials for advanced neutron multipliers for fusion applications owing to their high stability and low swelling. Because a large amount of beryllium is used for each solid breeding blanket in fusion reactors, the development of effective and efficient recycling processes is essential. In this study, a proper recycling process of Be12V pebbles was proposed, which combines a plasma sintering and a rotating electrode method for the fabrication of beryllide pebbles. As a result of experiments, it is determined that the rotating electrode method is available to reduce oxygen impurities, whereas the plasma sintering process can eliminate Li impurities and hydrogen isotope depending on sintering temperature. Regarding the recycling process, the beryllide pebbles used can be recycled into rods by plasma sintering, in which Li impurity and tritium can be eliminated. Then, recycled rods can be granulated by the rotating electrode method. During this process, it is anticipated that oxygen impurities and irradiation defects can be eliminated because the rotating electrode method includes the melting process. Thus, the current process was determined to be appropriate as a recycling process for beryllide pebbles.

A demonstration (DEMO) fusion reactor will require a huge amount of beryllium (Be) with approximately 490 tons. Since the total production of Be in the world, for now, is approximately 300 tons per year, it is anticipated that the demand is dramatically increased as the early realization of the fusion reactor proceeds. The presence of many Be mines, as well as information on each Be reserve, has already been confirmed with surveys. Since a conventional Be refinement process is considerably complicated including a production process for an intermediate product, Be(OH)2, high-temperature treatments, and handling of toxic powdery states, however, Be raw materials are costly. To provide a steady supply of Be for DEMO, in parallel with the development of mines, a novel Be refinement technique using an economical and safe process is imperative. According to these requirements, a novel and advanced refinement process of Be metal from ores was suggested by applying microwave melting at low temperatures through wet processing. It was obvious as a result of dissolubility tests that bertrandite and beryl ores were completely dissolved by using a process with acid solutions and microwave heating after treatment with base solutions and microwave heating. Further, the process can be utilized to produce not only intermediate products, such as beryllium hydroxide (Be(OH)2) and beryllium oxide (BeO) but also pure beryllium metal. Moreover, this process has great advantages for extracting uranium which is one of critical issues and oxide impurities for reuse.

We investigated the effect of royal jelly (RJ), a natural secretion from worker bees, on the endurance training-induced mitochondrial adaptations in skeletal muscles of ICR mice. Mice received either RJ (1.0 mg/g body weight) or distilled water for three weeks. The mice in the training group were subjected to endurance training (20 m/min, 60 min, 5 times/week). There was a main effect of endurance training on the maximal activities of the mitochondrial enzymes, citrate synthase (CS), and &beta, hydroxyacyl coenzyme Adehydrogenase (&beta, HAD), in the plantaris and tibialis anterior (TA) muscles, while no effect of RJ treatment was observed. In the soleus muscle, CS and &beta, HAD maximal activities were significantly increased by endurance training in the RJ-treated group, while there was no effect of training in the control group. Furthermore, we investigated the effects of acute RJ treatment on the signaling cascade involved in mitochondrial biogenesis. In the soleus, phosphorylation of 5&prime, AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) were additively increased by a single RJ treatment and endurance exercise, while only an exercise effect was found in the plantaris and TA muscles. These results indicate that the RJ treatment induced mitochondrial adaptation with endurance training by AMPK activation in the soleus muscles of ICR mice.