Implications of the new National Energy Basic Plan for nuclear waste management in Korea

The Korean National Energy Committee has recently adopted a new National Energy Basic Plan according to which the electricity generated by nuclear power plants is to increase from the current 35.5% of total electricity production to 59% by 2030. This large increase in nuclear power will inevitably accelerate the accumulation of spent fuel; if the direct disposal option is pursued, spent fuel arisings in Korea are expected to exceed 100,000 tHM in 2100. It is estimated that the country will require between 10–22 disposal sites, each with an area equal to the Gyeongju low- and intermediate-level radioactive waste (LILW) disposal site, to accommodate this amount of spent fuel. However, considering Korea's geographic profile, securing this number of sites will be almost impossible, and will ultimately create a serious problem for the sustainability of nuclear energy in the country. In view of this dilemma, this paper recommends that the volume of Korean nuclear waste for disposal be significantly reduced, and offers sodium fast reactor (SFR)-based recycling as a potentially viable solution.     

Effect of gamma irradiation and sulphitation treatments on keeping quality of white button mushroom Agaricus bisporus (J. Lge)

Gamma irradiation, alone and in combination with sulphitation, was tested for preventing the browning and maintaining the quality attributes of the white button mushrooms. Mushrooms were subjected to treatment of gamma irradiation in the dose range of 0.5–2.0 kGy and to combination treatments of sulphitation at a concentration of 0.1% potassium metabisulphite (KMS) and gamma irradiation (dose range 0.5–2.0 kGy) followed by storage at 10 ± 2 °C (RH 85%). A dose of 2.0 kGy significantly reduced the weight loss, prevented browning and mould growth. Cap and veil opening of mushrooms was delayed by 9 days and shelf life was extended by 12 days at a dose level of 2.0 kGy. Sulphitation alone at a concentration of 0.1% KMS was effective in controlling browning only upto 3 days, beyond which both browning and cap opening increased significantly ( P  ≤ 0.05) and the samples were unacceptable after 6 days of storage. No synergistic effect of sulphitation and irradiation was observed with respect to the shelf-life extension of mushroom.     

The effect of traditional wind vents called zarceras on the hygrothermal behaviour of underground wine cellars in Spain

This paper studies the hygrothermal behaviour of traditional underground wine cellars in one of the most important wine growing areas of Spain, the Ribera del Duero, paying special attention to the effects of traditional wind vents called zarceras. The purpose is to highlight energy-saving practices that aid the design and renovation of similar constructions. This was carried out by monitoring the temperature and relative humidity inside two wine cellars of similar properties throughout 2007, one with a zarcera and the other without. The results of the analysis show that the existence of the wind vent does not increase the ventilation from May to August. On the other hand, from September to March, the zarcera favours ventilation, affecting both temperature and relative humidity. The interior temperature is more greatly affected by the exterior temperature, giving rise to greater variations, although this difference is of little importance for maturing wine (annual variation 2.5 °C more than the cellar without a zarcera). The interior relative humidity is reduced, reducing the risk of condensation and problems of mould (the cellar without a zarcera reached excessively high values, 97% as an annual average, compared to 91% in the cellar with a zarcera). Thus the existence of zarceras in underground cellars improves the overall hygrothermal behaviour, providing suitable conditions for maturing wine without air conditioning systems, an advisable element in the building of new underground wine cellars.     

Measuring hydraulic properties of geotextiles after installation damage

Since geotextiles have been progressively incorporated into coastal protection structures, the influence of installation damage on them has been the primary concern. During installation/construction, geotextiles are repeatedly subjected to high mechanical stresses which often exceed service stress. It is therefore vital to evaluate the mechanical and hydraulic damage and determine the consequences of these damages to better develop criteria for selection of suitable products. As these damages could reduce the material's mechanical strength and hydraulic efficiency, or in the severest form of damage, puncturing, would end the separation function. The properties investigated in this paper include the permittivity and apparent opening size (AOS) of geotextiles. Generally, the greater the drop energy of armour units applied to geotextiles, the greater the potential for damage. Findings show that the residual permittivity could increase significantly, 45% during installation. The preliminary design of coastal structures will be optimised as engineers and designers can better estimate the amount of damage on geotextiles upon installation.     

黎平双江水电站拱坝开孔应力计算

在水电站工程建设中,拱坝因为其特有的优势因而被广泛使用在水电站中。在对拱坝进行设计的过程中,其开孔应力计算是一项重要的组成部分,对于拱坝的合理设计具有重要的作用,因此必须采取有效的措施对拱坝的应力进行计算。文章采用ANSYS建模分析在黎平双江水电站拱坝上开孔后对坝体应力问题,并根据计算成果分析开孔对拱坝的影响。     

基于能量理论的混凝土梁裂缝口张开位移分析

混凝土结构在未使用之前往往已经存在裂缝,在外荷载作用下,混凝土内部微裂缝会不断产生、扩展,成为混凝土破坏的根源,因此有必要计算混凝土已有裂缝口的张开位移。应用基于能量理论的裂缝扩展准则和虚拟裂缝模型,通过编程来模拟混凝土梁混合裂缝的扩展,对于混凝土梁裂缝口张开位移的计算是有效的;切口深度增大时,裂缝口张开位移增大;弹性模量增大时,裂缝口张开位移减小,混凝土的抗裂性能得到加强。     

世行贷款项目国内竞争性招标与国内项目公开招标的区别

结合世行贷款江苏省淮河流域重点平原洼地治理项目泰东河工程招标投标工作,对比分析世行贷款项目国内竞争性招标与国内项目公开招标两种方式,从招标过程中的各环节差异提出应重点关注的问题,为做好类似项目招标投标提供一定借鉴.     

龙开口水电站初期下闸蓄水规划设计与实施

龙开口水电站初期蓄水阶段,采用导流底孔闸门局部开启的过流方式,顺利下泄环保流量,满足环保要求。结合蓄水时间对下闸时机进行了深入分析,为合理决策下闸时机提供了依据,对类似工程有一定借鉴作用。     

控制马湾闸前水位变率实现多发电

马湾拦河闸水利枢纽利用闸前水位~库容关系曲线和闸门开度-水位-泄量关系表作出水位变率-闸门开度变量关系表,根据水位变率实现了高水位发电。     

用非连续变形法分析岩锚吊车梁稳定性

岩锚吊车梁是水电站地下厂房重要建筑物之一,其稳定分析方法一直是一个值得探讨的问题。文章用DDA对某水电站地下厂房的岩锚吊车梁稳定性进行分析,把所分析的结果与常规的刚体极限平衡法的计算结果进行了对比,两者结果是一致的,由此说明DDA所分析的成果是可靠的,DDA程序可以用来分析岩锚吊车梁稳定性。