• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.239-245
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• 2010

There are 11,811 LWR spent fuels stored at reactor sites, as of 2009. Source terms based on reference spent fuel which represents entire spent fuels with bounding values in the aspect of source term has been applied to a design of nuclear installations, instead of those which are generated by weighting respective source term for each spent fuel. Simplified regression models to estimate total decay heat, radioactivity, and ingestion hazard index for spent fuel from Westinghouse-type reactors were developed in this study, because it can be used as a fundamental model for weighting source term for respective spent fuel to exclude conservativeness in source terms. It was found that the estimated source terms agreed with calculated value from ORIGEN-ARP within 5%. It was also found that the conservativeness could be excluded if the weight source terms were used as reference source term in the design. Therefore, it is expected that the developed regression model could be widely used in the conceptual design process of nuclear facilities related with storage and disposal of spent nuclear fuel.

• Nuclear Engineering and Technology
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• v.39 no.1
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• pp.31-42
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• 2007

Energy supply is increasingly showing up as a major issue for electricity supply, transportation, settlement, and process heat industrial supply including hydrogen production. Nuclear power is part of the solution. For electricity supply, as exemplified in Finland and France, the EPR brings an immediate answer; HTR could bring another solution in some specific cases. For other supply, mostly heat, the HTR brings a solution inaccessible to conventional nuclear power plants for very high or even high temperature. As fossil fuels costs increase and efforts to avoid generation of Greenhouse gases are implemented, a market for nuclear generated process heat will be developed. Following active developments in the 80's, HTR have been put on the back burner up to 5 years ago. Light water reactors are widely dominating the nuclear production field today. However, interest in the HTR technology was renewed in the past few years. Several commercial projects are actively promoted, most of them aiming at electricity production. ANTARES is today AREVA's response to the cogeneration market. It distinguishes itself from other concepts with its indirect cycle design powering a combined cycle power plant. Several reasons support this design choice, one of the most important of which is the design flexibility to adapt readily to combined heat and power applications. From the start, AREVA made the choice of such flexibility with the belief that the HTR market is not so much in competition with LWR in the sole electricity market but in the specific added value market of cogeneration and process heat. In view of the volatility of the costs of fossil fuels, AREVA's choice brings to the large industrial heat applications the fuel cost predictability of nuclear fuel with the efficiency of a high temperature heat source tree of Greenhouse gases emissions. The ANTARES module produces 600 MWth which can be split into the required process heat, the remaining power drives an adapted prorated electric plant. Depending on the process heat temperature and power needs, up to 80% of the nuclear heat is converted into useful power. An important feature of the design is the standardization of the heat source, as independent as possible of the process heat application. This should expedite licensing. The essential conditions for success include: ${\bullet}$ Timely adapted licensing process and regulations, codes and standards for such application and design ${\bullet}$ An industry oriented R&D program to meet the technological challenges making the best use of the international collaboration. Gen IV could be the vector ${\bullet}$ Identification of an end user(or a consortium of) willing to fund a FOAK

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1573-1579
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• 2013

To test the performance of nuclear fuels, coolant needs to be circulated through the test rig installed in the test loop. Because the pressure and temperature of the coolant is 15.5 MPa and $300^{\circ}C$ respectively, coolant sealing is one of the most important processes in fabricating a nuclear fuel test rig. In particular, 15 instrumentation cables installed in a test rig pass through the pressure boundary, and brazing is generally applied as a sealing method. In this study, an induction brazing system has been developed using a high frequency induction heater including a vacuum chamber. For application in the nuclear field, BNi2 should be used as a paste, and optimal process variables for Ni brazing have been found by several case studies. The performance and soundness of the brazed components has been verified by a tensile test, cross section test, and sealing performance test.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.1-17
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• 1977

Nitrogen responses to yield and other agronomic characters were studied using four rice varieties, Tongil, Jinheung, Milyang 23, and Yushin, at six nitrogen levels, 0, 10, 15, 20, 25 and 30kg/10a, in a silt loam soil at the Crop Experiment Station, Suweon, Korea, in 1976. Grain yields of Milyang 23 and Tongil were much higher than those of Jinheung and Yushin at high nitrogen levels (15-30kg/10a). Optimum nitrogen levels of the rice varieties, Tongil, Milyng 23, Yushin, and Jinheung, estimated by intersecting straight line, were 22, 19, 19, and 12kg/10a, respectively. Morpshological characters, dry matter production before and after heading, and yield components were dicussed in relation to the nitrogen responsivenees of the rice varieties. In addition, relationships between yield, yield components, and other agronomic characters were discussed to obtain some informations for higher rice yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.1
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• pp.62-72
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• 1985

In order to find out the effects of seeding time on growth, dry matter production and nutritive content of Pioneer 931, Pioneer 988 and Piper, this study was carried out on the experimental field of Livestock Experiment Station in 1981-83. Seeding time were 7 with 14-day interval from April 16 to July 9. The results are summarized as follows: 1. It tool about 12 to 13 days from seeding to emergence in case of Mid-April seeding and 7 to 8 days in Late-June. Earlier seeding, more longer growth period from emergence to heading they required. 2. Plant height of Pioneer 931 seeded lately was longer than 4.5 meters in primary growth and Sudangrass was about 2.0 to 2.5 meters. Leaf area was the greatest in Mid-August by early seeding but it was increased until Early-October by late seeding. 3. Sorghum gas brought the highest yield in dry mater and Sudangrass the lowest. In general dry matter yield reduced gradually in response to later seeding but Pioneer 931 has brought more than 10 tons per hecter until Late-June. 4. Relative Growth Rate, Leaf Area Ratio and Leaf Weight of all varieties decreased in accordance with growth development. 5. Crude protein content of leaf was higher than stem and the younger the plants, the more protein they contain. Nitrogen Free Extract was just opposite to crude protein.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.2
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• pp.121-126
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• 1985

Phytotron and field experiments were conducted to determine the influence of morphological growth stage and environmental temperature on synthesis and accumulation pattern of cyanogenic glycosides in sorghum cv. Pioneer 931 and Sioux at Munich technical university from 1979 to 1980. Various growth stages of sorghum plants were grown in phytotron at 4 different temperature regimes of 30/25, 25/20, 28/18 and 18/8 degree C with 35,000 Lux over 13-h days. The results obtained are summarized as follows: 1. Cyanogenic glycosides in sorghum plants were shown to have a great synthetic rate at early growth stages. The highest concentrations of hydrocyanic acid (HCN) were found at 2-leaf stage with 2384 and 1800ppm (DM basis) for Pioneer 931 and Sioux respectively. The contents of HCN were, however, however decreased markedly as morphological development, which shows a value of 173ppm (Pioneer 931) and 70ppm (Sioux) at heading stages. 2. Changes of hydrocyanic acid in sorghum plants were positive correlated with leaf weight ratio and leaf area ratio ($P{\leqq}0.1%$), while plant height shows a negative correlation with HCN contents ($P{\leqq}0.1%$). 3. Cyanogenic glycosides were accumulated in young plants mainly in leaves. During the late maturities, the contents of HCN in leaves and stalks were shown, however, a similar distribution. 4. Synthesis rates of cyanogenic glycosides were increased under high temperature. Accumulated hydrocyanic acid in the plants was, however declined when temperature exceeded 30 degree C. 5. Synthesis rates of cyanogenic glycosides were affected by nitrogen reductase activity (NRA). The concentration of hydrocyanic acid in sorghum plants was associated with increasing of nitrate-N accumulation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.180-186
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• 1985

Field and phytotron experiments were conducted to determine the effect of morphological growth stage and environmental temperature on Weender components and net energy lactation (NEL) in corn cv. Blizzard and sorghum cv. Pioneer 931 and Sioux at Munich Technical University from 1978 to 1981. Various growth stages of maize and sorghum were grown for 42 days at 4 temperature regimes (30/25, 25/20, 28/18 and 18/8 degree C) and mid-summer sunlight over 13 hour days. The results obtained are summarized as follows: 1. Accumulation of crude protein in maize and sorghum plants was associated with leaf weight ratio and leaf area ratio ($P{\leq}0.1%$). Crude protein in the plants were shown to have a greate synthesis rates at early growth stages. The highest concentration of crude protein were found at 3-leaf stage with 31.4% and 33.9% for maize and sorghum, respectively. 2. Synthesis of crude fiber was increased after growing point differentiation markedly and were shown the highest concentration at heading stage with 28.4% and 31.5% for maize and sorghum, respectively. During the maturities, the crude fiber contents in maize were, however decreased and shown a value of 19.5% at physiological maturity, while that of sorghum were increased continuously. 3. NEL value in maize and sorghum plants were declined as morphological development and shown the lowest at growing point differentiation with 5.82 MJ (maize) and 5.46 MJ/kg (sorghum). During the late maturity, the NEL value of maize were increased markedly and shown a value of 6.70 MJ and 6.94 MJ/kg for milkstage and maturity stage, respectively, while NEL value in sorghum were not increased markedly. 4. Net energy lactation in maize and sorghum plants were associated with synthesis rate of non-structural carbohydrates, especially mono- and disaccharose while cell-wall constituents and crude fiber lowerd NEL contents ($P{\leq}0.1%$). 5. NEL accumulation and starch value were decreased under temperature. The NEL concentration of 4-leaf sorghum under different environmental temperatures of 30/25, 25/20, and 18/8 degree C were 4.87 MJ, 5.46 MJ and 5.81 MJ/kg, respectively.

• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.172-180
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• 2023

In the current study, four groups; control, 500, 1000, and 2000 mg/L, were treated to investigate the effects of physiological and growth characteristics on Machilus thunbergii under various fertilization levels. As a result of the physiological response to the fertilization treatment, the fertilized group demonstrated relatively higher levels of A, ITE, WUEi, V_camx, PI_abs, and SFI_abs in comparison to the control. The best photosynthetic mechanism was most clearly seen at 1000 mg/L, which involved gas exchange through active stomatal opening and closing. For a productive photosynthetic mechanism. As seen in the growth response of M. thunbergii to fertilization treatment, the fertilized group has significantly higher height, DRC, leaf dry weight, stem dry weight, total dry weight, LWR, and SWR than the control group. A healthy seedling quality index was particularly evident at 1000 mg/L, and other growth indicators were also at a decent level. 500 mg /L also demonstrated growth characteristics that were comparable to those at 1000 mg/L. As a result, M. thunbergii featured the best physiological and growth characteristics in response to the fertilization treatment at 1000 mg/L, and 500 mg/L also showed a similar trend, which is considered to be a good option from an economical perspective.