• Nuclear Engineering and Technology
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• 제56권3호
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• pp.803-811
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• 2024

Nuclear accidents such as Fukushima Daiichi have highlighted the potential of passive safety systems to replace or complement active safety systems as part of the overall prevention and/or mitigation strategies. In addition, passive systems are key features of Small Modular Reactors (SMRs), for which they are becoming almost unavoidable and are part of the basic design of many reactors available in today's nuclear market. Nevertheless, their potential to significantly increase the safety of nuclear power plants still needs to be strengthened, in particular the ability of computer codes to determine their performance and reliability in industrial applications and support the safety demonstration. The PASTELS project (September 2020-February 2024), funded by the European Commission "Euratom H2020" programme, is devoted to the study of passive systems relying on natural circulation. The project focuses on two types, namely the SAfety COndenser (SACO) for the evacuation of the core residual power and the Containment Wall Condenser (CWC) for the reduction of heat and pressure in the containment vessel in case of accident. A specific design for each of these systems is being investigated in the project. Firstly, a straight vertical pool type of SACO has been implemented on the Framatome's PKL loop at Erlangen. It represents a tube bundle type heat exchanger that transfers heat from the secondary circuit to the water pool in which it is immersed by condensing the vapour generated in the steam generator. Secondly, the project relies on the CWC installed on the PASI test loop at LUT University in Finland. This facility reproduces the thermal-hydraulic behaviour of a Passive Containment Cooling System (PCCS) mainly composed of a CWC, a heat exchanger in the containment vessel connected to a water tank at atmospheric pressure outside the vessel which represents the ultimate heat sink. Several activities are carried out within the framework of the project. Different tests are conducted on these integral test facilities to produce new and relevant experimental data allowing to better characterize the physical behaviours and the performances of these systems for various thermo-hydraulic conditions. These test programmes are simulated by different codes acting at different scales, mainly system and CFD codes. New "system/CFD" coupling approaches are also considered to evaluate their potential to benefit both from the accuracy of CFD in regions where local 3D effects are dominant and system codes whose computational speed, robustness and general level of physical validation are particularly appreciated in industrial studies. In parallel, the project includes the study of single and two-phase natural circulation loops through a bibliographical study and the simulations of the PERSEO and HERO-2 experimental facilities. After a synthetic presentation of the project and its objectives, this article provides the reader with findings related to the physical analysis of the test results obtained on the PKL and PASI installations as well an overall evaluation of the capability of the different numerical tools to simulate passive systems.

• 한국식품과학회지
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• 제11권4호
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• pp.291-297
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• 1979

시험 재배한 4가지 감자 품종(Irish Cobbler, Warba, Shimabara, Saco)을 동결 건조하여 분말을 만든 다음, 유리(遊離) 및 결합(結合) 지질(脂質)을 추출하고 이의 구성 지방질의 구성 부분을 관 크로마토그래피, 가스-액체 크로마토그래피 등의 방법으로 분리 정량하여 비교한 결과 다음과 같은 결론을 얻었다. 1. 감자의 건조물(乾燥物) 중 총(總) 조(粗) 지방(脂肪) 질량(質量)은 평균 0.57 %였으며 이중에서 유리(遊離) 지질(脂質)은 0.2 %였고 결합(結合) 지질(脂質)은 0.37 %로 결합(結合) 지질(脂質)의 함량이 유리(遊離) 지질(脂質) 보다 0.17%정도 많았다. 2. 유리(遊離) 지질(脂質) 중의 중성(中性) 지질(脂質) 함량은 14.9 %로 결합(結合) 지질(脂質) 중의 4.5 % 보다 약 3배 정도 많았고, 당지질(糖脂質)의 함량은 유리(遊離) 지질(脂質) 중에는 15.1 %로 결합(結合) 지질(脂質)중의 2.22 %보다 약간 적은 편이었다. 그러나 인지질(燐脂質)의 함량은 결합(結合) 지질(脂質) 중에는 33.9 %로 유리(遊離) 지질(脂質)의 7.2 %보다 4.5배 정도로 월등하게 많았다. 그러므로 감자 중의 결합(結合)은 주로 당지질(糖脂質)과 인지질(燐脂質)로 구성되어 있고, 유리(遊離) 지질(脂質) 중에는 중성(中性) 지질(脂質)과 당지질(糖脂質) 및 인지질(燐脂質) 함량이 서로 비슷하였다. 3. 총(總) 유리(遊離) 및 결합(結合) 지질(脂質)을 구성하는 주된 지방산은 모두 linoleic, palmitic 및 linolenic acids로 90 % 이상 이었다. 그러나 유리(遊離) 지질(脂質) 중에는 결합(結合) 지질(脂質) 보다 포화 지방산의 함량은 다소 적었고 불포화 지방산의 함량은 많은 편이었다.