The Molten Salt Reactor (MSR) is considered one of the most suitable technology for micro mobile reactors due to its low operating pressure (3 ~ 5 atmospheres), which reduces weight and volume compared to pressurized water reactors (PWRs). Unlike PWRs, MSRs use molten salt as both fuel and coolant, enabling compact and transportable designs. This study outlines the conceptual design of a micro mobile MSR and establishes safety criteria for transient states. It proposes strategies for managing the primary loop, intermediate heat transfer system, and air-cooled Balance of Plant (BOP) while addressing thermal and structural constraints, such as maximum temperatures and molten salt freezing points. Control approaches for reactor output and BOP systems are analyzed, highlighting fast response and adaptability to frequent power changes. The study also compares fixed-speed and variable-speed pump operations and provides a framework for operational modes, from high-temperature standby to transport-ready conditions. These findings offer a foundation for efficient, safe, and flexible MSR deployment.

Ethyl formate (EF) is a naturally occurring insecticidal compound and is used to control pests introduced from abroad, in quarantine, by a fumigation method. In particular, it is mainly used as a substitute for methyl bromide and is less toxic to humans and less harmful to plants. This study aimed to investigate the possible acute toxicity of EF to useful organisms, and how to reduce phytotoxicity in watermelon, zucchini, and oriental melon. After fumigation with EF for 2 h, the LC50 values for earthworms, honey bees, and silkworms were 39.9, 7.09, and 17.9 g m-3, respectively. The degree of susceptibility to EF was in the order of earthworms, silkworms, and honey bees based on the LC50 value, and EF fumigation induced stronger acute toxicity to honey bees. Phytotoxicity was observed in watermelon leaves treated with a concentration of 7.5 g m-3 EF, and when treated with a concentration of 10.0 g m-3, it was confirmed that the edges of watermelon leaves were charred and seemed to be damaged by acids. Zucchini and melon, and other cucurbits, showed strong damage to the leaves when treated with a concentration of 10 g m-3, and sodium silicate, at concentrations of 10% and 20%, was used to reduce phytotoxicity. Therefore, acute toxicity towards nontarget organisms and phytotoxicity during the fumigation of EF should be reduced for efficient agricultural pest control.

본 연구는 국내에서 재배되고 있는 절화 장미 품종들에 있 어서 바이러스 감염 여부를 검정하기 위해 실시하였다. 절화 장미의 주산지인 경기도 G시의 장미재배 농장에서 8품종을, 경상남도 C시의 장미재배 농장에서 10품종을, 전라남도 H군 의 장미재배 농장에서 14품종을, 전라북도 J군의 장미재배 농 장에서 9품종 등 총 41품종을 대상으로 ArMV, INSV, TMV, ToRSV, TRSV, TSV, TSWV 등 총 7종류의 바이러스에 감염되었는지를 ImmunoStrip® kit를 이용하여 검정하였 다. 경기도 G시의 장미 재배농장의 ‘Bobos’, ‘Pink Army’, ‘15-712’, ‘18-356’은 TRSV에 감염된 것으로 나타났고, 경상 남도 C시의 장미 재배농장의 ‘Haesal’은 TMV, ‘Querencia’ 는 ToRSV에 감염된 것으로 나타났다. 전라남도 H군의 장미 재배농장의 ‘Deep Purple’은 ArMV와 TRSV에, ‘Lady of Shalott’은 TRSV, ‘Mortimer Sackler’는 TMV와 TRSV, ‘Natal Briar’는 ArMV와 INSV에, ‘Sprit of Freedom’은 INSV, ‘Imogen’은 TRSV, ‘Pink Beauty’는 ArMV, TMV, TRSV에 감염된 것으로 조사되었다. 전라북도 J군의 장미 재배농장의 ‘Amor Zen’, ‘Dignity’, ‘Peach Pangpang’, ‘Yellow Pangpang’ 등 4개 품종은 TRSV에 감염된 것으 로 나타났고, 본 연구에서 조사한 총 41개 품종 중 22개 품 종이 바이러스에 감염되었으며, TRSV에 13 품종이, ArMV와 TMV에 3 품종이, INSV에 2 품종이, ToRSV에 1 품종이 감 염되어 TRSV에 가장 많이 감염된 것으로 나타났다.

우리나라는 기상 악화 속에서 감항성이 확보된 선박만이 항해할 수 있도록 선박출항을 해사안전법에 근거하여 통제하고 있으 나 통제 대상선박 지정에 대한 과학적 평가 결과 및 정량적 근거가 미비하여, 항행안전의 확보와 합리적 출항통제 운영을 위한 개선 의견 이 제기되고 있다. 본 연구는 풍랑 주의보 발효 시 주요 통제대상 선종인 예인선의 실선계측을 통해, 현행 출항통제 기준의 적정성을 평 가하고 현실성 있게 개선될 수 있도록 정량적 근거를 제시하는 것에 연구 목적이 있다. 이를 위해 예인선에 선박의 3축 운동과 선체가속 도를 측정하는 Sensor를 설치하여 유의파고 3m인 해역 내에서 운항하여 선체운동 성능을 계측하였고, 계측된 수치를 내항성능 평가요소 및 한계 값 기준을 바탕으로 비교 분석하였다. 실측 선박은 톤수에 따른 현행 통제기준에서 제외되었으나, 분석 결과 Pitch 값이 Operation 기준을 넘어 항행안전에 위험성이 존재하였다. 본 연구 결과는 선박 출항통제 대상에 대한 검토와 다양한 선종 및 제원을 대표할 수 있는 추가적 실측연구가 필요함을 시사한다.

Most of the steam turbine control valves used for the fossil and nuclear power plants operation in South Korea were developed by GE (General Electric) and manufactured by DHIC (Doosan Heavy Industry Company). For may years, DHIC have tried to develop their own technologies related to the power generation. DHIC has launched many R&D projects and ‘Development of a Control Valve Flow Code for Steam Turbine Operation Control of Fossil Power Plant’ was one of the R&D projects. Through our project, we accomplished the experimental method to obtain a steam turbine control valve characteristic curve using the atmospheric air and the reduced model instead using the steam and the real model. Also, we developed the correction method to calculate the real steam mass flow rate from the characteristic curve obtain by the experiment. In this paper, the effectiveness of the correction method was reviewed and it was concluded that the corrected mass flow rate complies well with the real steam mass flow rate.