The intermediate level spent resins waste generated from water purification for the the moderator and primary heat transport system during operaioin of heavy water reactor (HWR). Especially, moderator resins contain high level activity largely because of their C-14 content. So spent resins are considered as a problematirc solid waste and require special treatment to meet the waste acceptance criteria for a disposal site. Various methods have been studied for the treatment of spent resins which include thermal, destructive, and stripping methods. In the case of solidification methods, cement, bitument or organic polymers were suggested. In the 1990s, acid stripping using nitric acid and thermal treatment methods were actively investigated in Canada to remove C-14 nuclide from waste resin. In Japan, thermal distructive method was studied in the 1990s. Since 2005, KAERI developed acid stripping method using phosphate salt. However, acid stripping method are not suitable due to large amounts of 2nd waste containing acid solution with various nuclides. To solve this probelm, KAERI has been suggested the microwave treatment method for C-14 selective removal from waste resin in the 2010s. Pilot scale demonstration tests using radioactive waste resin generated from Wolsung unit 1 and unit 2 were successfully conducted and 95% of C-14 was selectively removed from the radioactive waste resin. In recent years, price of C-14 source is dramatically increased due to market growth of C-14 utilization and exclusive supply chain depending on China and Russia. High purity of C-14 were captured in HWR waste resin. Interest of C-14 recovery research from HWR waste resin is currently increased in Canada. In this study, microwave method is suggested to treat HWR waste resin with C-14 recovery process. Additionally, status of waste resin management and research trends of HWR waste resin treatment are introduced.

최근 국내에서 세계 최초로 개발한 SWRO-PRO 복합해수담수화 시스템은 압력지연삼투(PRO) 기술을 활용하여 역삼투(SWRO) 해수담수화 플랜트에서 발생하는 고염도 농축수의 삼투에너지를 회수하는 기술이다. 고염도 농축수와 저염도 하수처리수를 각각 PRO 시스템의 유도용액과 유입수로 사용하며, 두 용액의 농도차에 의해 발생되는 삼투에너지를 압력교환장치(isobaric pressure exchanger)를 통해 회수하여 SWRO 고압펌프에서 필요한 에너지를 줄이거나, 터빈 형태의 에너지 회수장치(Pelton turbine)를 통해 전력을 생산하는 기술이다. PRO 시스템을 통해 회수된 에너지는 해수담수화 운영비를 절감하는데 기여하고, 고농도 농축수의 희석 방류로 해양생태계 영향을 최소화 시킬 수 있다.

The ovum pick up(OPU) technique can be used to produce embryos after in vitro culture of ovarian oocytes, can be used for early securement for effective herd early proliferation and excellent Hanwoo genetic resources, It is attracting attention as a very important technique for establishing technology. In addition to in vitro culture techniques, the number of oocytes retrieved depends on the environment and timing of the OPU. This study was conducted to compare and examine seasonal effect to the differences in the number of recovered oocytes, recovery rate and embryo development rate using Korean cattle kept in animal genetic resource research center by OPU technique. The grade of COCs was evaluated by microscopic examination. Grade A had 3 or more layers of cumulus cell and compact cytoplasm. Grade B had 1~3 layers of cumulus cell and compact cytoplasm. Grade C had 1 layers cumulus cell and compact cytoplasm. Grade D was denuded oocyte and poor cytoplasm. The recovery rate was 47.8±3.4% in summer (June to August) and 51.6±3.8% in autumn (September to October). The number of oocytes was 5.7±0.6 in summer and 5.2±0.7 in autumn. Oocyte grade A and B was 46.2%±6.3% in summer and 51.1±5.0% in autumn. The cleavage rate was 46.1±7.1% in summer and 65.0±11.3% in autumn. Blastocyst development rate was 19.9±9.4% in summer and 29.0±8.7% in autumn. There was no difference the recovery rate of oocytes and the number of embryos between summer and autumn. Cleavage rate and blastocyst rate of autumn was higher than summer. we will investigate to study the appropriate method for the production of Hanwoo embryos and the systematic comparison.

Biogas produced in anaerobic digestion process has been considered as a renewable energy source. To recover biogas from the anaerobic effluent and thereby maximize the energy recovery from anaerobic processes, membrane contactor employing hydrophobic porous hollow fiber membrane has been applied. By optimizing the surface hydrophobicity and the porosity of membranes, a desirable CH4 flux could be achieved. Biogas recovered can be upgraded by applying required purification processes for the injection into natural gas grid or for the use as vehicle fuel. My group has synthesized various microporous materials including zeolites, metal-organic frameworks (MOFs) and amine-appended sorbents that are selectively transport CO2 molecule and incorporated them into polymeric films to design high performance gas separation membranes.

Phosphorus (P) is a limited, essential, and irreplaceable nutrient for the biological activity of all the living organisms. Sewage sludge ash (SSA) is one of the most important secondary P resources due to its high P content. The SSA has been intensively investigated to recover P by wet chemicals (acid or alkali). Even though H2SO4 was mainly used to extract P because of its low cost and accessibility, the formation of CaSO4 (gypsum) hinders its use. Heavy metals in the SSA also cause a significant problem in P recovery since fertilizer needs to meet government standards for human health. Therefore, P recovery process with selective heavy metal removal needs to be developed. In this paper some of the most advanced P recovery processes have been introduced and discussed their technical characteristics. The results showed that further research is needed to identify the chemical mechanisms of P transformation in the recovery process and to increase P recovery efficiency and the yields.

Flat panel display devices are mainly used as information display devices in the 21st century. The worldwide waste flat panel displays are expected at 2-3 million units but most of them are land-filled for want of a proper recycling technology More specifically, rare earth metals of La and Eu are used as fluorescent materials of Cold Cathode Flourscent Lamp(CCFL)s in the waste flat panel displays and they are critically vulnerable and irreplaceable strategic mineral resources. At present, most of the waste CCFLs are disposed of by land-filling and incineration and proper recovery of 80-plus tons per annum of the rare earth fluorescent materials will significantly contribute to steady supply of them. A dearth of Korean domestic research results on recovery and recycling of rare earth elements in the CCFLs prompts to initiate this status report on overseas research trends and noteworthy research results in related fields.

To improve the performance of wide-issue superscalar processors, it is essential to increase the width of instruction fetch and the issue rate. Removal of control hazard has been put forward as a significant new source of instruction-level parallelism for superscalar processors and the conditional branch prediction is an important technique for improving processor performance. Branch mispredictions, however, waste a large number of cycles, inhibit out-of-order execution, and waste electric power on mis-speculated instructions. Hence, the branch predictor with higher accuracy is necessary for good processor performance. In global-history-based predictors like gshare and GAg, many mispredictions come from commit update of the branch history. Some works on this subject have discussed the need for speculative update of the history and recovery mechanisms for branch mispredictions. In this paper, we present a new mechanism for recovering the branch history after a misprediction. The proposed mechanism adds an age_counter to the original predictor and doubles the size of the branch history register. The age_counter counts the number of outstanding branches and uses it to recover the branch history register. Simulation results on the SimpleScalar 3.0/PISA tool set and the SPECINT95 benchmarks show that gshare and GAg with the proposed recovery mechanism improved the average prediction accuracy by 2.14% and 9.21%, respectively and the average IPC by 8.75% and 18.08%, respectively over the original predictor.

폐기물로부터 에너지를 회수하고자 하는 노력은 전세계적인 추세이며, 국내에서도 가연성 폐자원의 효율적인 친환경적 처리, 에너지 회수를 위한 다양한 정책과 법규가 만들어져 진행되고 있다. 가연성 폐기물로부터 에너지를 회수하는 전통적인 방법인 소각과 비교하여 가스화 기술은 생산된 합성가스를 다양한 방법으로 활용할 수 있다는 장점을 보유하고 있다. 합성가스가 가지고 있는 화학적 에너지를 활용하여 직접 엔진을 가동할 수 있으며, 가스화 방식에 따라 합성가스 내에 포함된 수소, 일산화탄소 등의 성분을 화학반응의 원료로 사용할 수도 있다. 따라서, 국내에서도 폐기물로부터 얻어진 합성가스를 다양한 방법으로 활용하기 위한 많은 연구들이 진행중에 있다. 본 연구에서는 국내 지자체에서 발생되는 생활폐기물의 비성형고형연료화 및 가스화 발전 기술을 적용하여 폐기물이 갖는 에너지를 회수하고자 비성형고형연료 8톤/일 규모의 하향식 고정층 가스화로와 세정설비, 가스엔진 발전을 통해 약 250kW이상의 전력을 생산하는 시스템을 설치 및 운영하였으며, 실증설비의 설계를 위한 다양한 인자에서의 결과를 알아보았다. 가스화 특성에 따른 발전 효율을 토대로 가스화 기술의 경제성을 평가함에 따라 상용공정으로의 적용 가능성을 확인할 수 있었다.

In this research, the upgrading technology and policy trends for biogas were examined with a focus on the European Union (EU). Depending on the capacity of the biogas upgrading facility investment costs are different. In addition, biogas upgrading technology-specific energy demand is lowest in the amine scrubber process. Organic waste met the sustainability criteria. Also, the energy content was four times larger, and the results showed that the utilization value was significant. Through cogeneration, and it can secure various markets. Because of these advantages, various policies are being promoted in the EU. In the future, South Korea needs to model its biogas policy after the upgrading technology and policy trends in the EU, and it should strive to create a market for biomethane.

The present research examined the technological trends in optimizing the gasification of waste. Generally, when the percentage of impurities in waste is high, the energy density is low. High-temperature and high-pressure steam is difficult to obtain during energy recovery in incineration. Therefore, the energy recovery rate is low. However, if reaction conditions were optimized in gasification technology, it would be possible to produce synthetic gas with a high percentage of CO and H2. With regard to synthetic gas, there are many different types of energy recovery (steam turbines, gas turbines, gas engines) other than incineration, and it is possible to improve the recovery ratio through gas cleaning. Technologies that have the potential to optimize gasification in each phase were studied. With regard to domestic industry, optimization technology should be applied when planning and operating waste gasification.

This study describes the design and corrosion-resistant materials for a high-efficiency waste-to-energy (WtE) plant. WtEtechnology is one of the most robust and effective alternative energy options to reduce CO2 emissions and to conservelimited fossil fuel resources, which are used by traditional power plants. The recently published 3rd edition of the CEWEP(confederation of european waste-to-energy plants) energy efficiency report demonstrated the energy efficiency criterion(R1 formula) that was introduced in the waste framework directive and has proven to be an incentive for WtE plants inEurope to improve their energy efficiency. The design combines the optimal use of the corrosion resistant properties ofinconel with an efficient boiler design (Amsterdam) and turbine layout. It uses a steam-steam reheater to realize thisefficiency as well as high availability and low maintenance. The high-efficiency WtE plant is an economical choice thatmakes a very positive contribution to sustainable electricity production.