The stability and safety of operation of a reactor is determined mainly by the sign and magnitude of its reactivity responses to temperature changes. Reactors are subject to temperature fluctuations due to the changes in reactor power and ambient temperature. These temperature fluctuations cause reactivity disturbances through changes in the nuclear and physical properties of the core. Because of these important phenomena by the temperature effects, a large portion of study and testing on a reactor design has been conducted. In this experiment the overall temperature coefficient of the TRIGA MARK-II reactor is measured. The basic procedure is to change the tgemperature of the water moderator, and from the movements of a newly recalibrated control rod(this is necessary due to the effects of fuel burn-up and control rod depression) required to mintain criticality, the reactivity worth of the temperature change is determined. From this measurement, the overall temperature coefficient seems to be smoothly varying, almost a linear function of temperature, and a value of approximately -0.267${\c}$/$^{\circ}C$ can be obtained for an average temperature range from $17.6^{\circ}C$ to $32.5^{\circ}C$.

As a power system gets complicated and the number of regulating points increases, the voltage reactive power control tends to be more complex and more difficult. In the past, we took only the voltage regulation into account for this voltage control problem. pay attention not only to the voltage regulation but also to the rational system operation which minimizes transmission losses. Considering the rehuirements mentioned above we aim developing a method of coordination of these regulating equipments and also present some preliminary discussions aboutcomputer control of power systems which is now frequently available with the progress of digital computer technique.

This paper, as an attempt to meet the practical needs in the fire protection field of Korea, has dealt with establishing the identification criteria and prevention theory of electrical fire. The causes analysis of electrical fire was already conducted and then reported by the authors in the Journal of the Korean Institute of Electrical Enginers, October, 1966. This paper is, therefore, the next results of a series of studies on the causes and identification of electrical fire.

This paper derives the useful formulas for computing annual profits, and economical size, locations and regulating values of parallel shunt capacitors in case that they are installed in a distribution line. Inparticular, the derived formulas consider the influence of load variations in order to represent the actual load situations.

This voltage Regulator, which regulates voltage in different way from the conventional regulator, is constructed by circular-plate core type stators and controllers (are similar to rotor of conventional). The principle of this Voltage Regulator is based on the rotating magnetic field theory including peculiar homopolar and heteropolar concept. Comparing with the conventional induction regulator, this regulator need not to have short windings and can cancel armature reaction. Moreover, it is able to decrease the machine noise and control the phase of it freely. And it's efficiency can become more than 95% which almost the same as that of transformer's. By increasing numbers of cores of the same size, the output power can be increased, the insulation can be decreased and high Voltage can directly be connected because applied voltage is distributed to each core. This Voltage Regulator can be also used as a current regulator, a starter a induction motor and a phase transformer etc.

한국전력기술부에서는 팽대한 전원개발에 따른 전력계통제문제를 가까운 장래 구체적으로 검토할 계획을 가지고 있으나, 이에 앞서 일본 조도전대학 전력공학연구실의 협력을 얻어 제2차 5개년 계획기간중인 1969년도 및 그 최종년도인 1971년도에 있어서의 수급계획에 따른 기본조류문제 및 계통증강문제의 기초적인 검토를 Digital계산기를 이용하여 실시하였기에 그 내용의 일부를 보고하는 바이다.

본 조사연구는 한국전력주식회사의 위탁에 의하여 1967년 1월 초순에서 중순에 걸쳐, 서울대학교공과대학 응용과학연구소의 염영하, 현병구, 김동기 제교수와 같이 실시한 것이다. 즉 청평발전소 제3호 발전기(40,000KW) 설치장소의 굴착작업이 이전시설 특히 제1호와 제2호 발전기 및 그 부대시설에 미치는 영향을 조사하고, 굴착의 최적작업방법을 제시한 것이다.