[en] Critical specifications of Thor, an old assembly of thorium-reflected plutonium, have been refined. These specifications are brought together with void coefficients, Rossi-alpha values, fission traverses, and spectral indices

No abstract available

[en] Tsing Hua Open-pool Reactor (THOR) is a swiming pool type research reactor operated and maintained by the University. The functions of THOR are two folds, i.e. (1) teaching and training of nuclear scientists and engineers, and (2) promotion of peaceful uses of atomic energy in Taiwan. Thus, besides the educational program THOR has been offering neutron irradiation service on regular schedule (30 hrs. per week full power operation at 1 MW with neutron flux of ca. 2 x 10¹² n cm^-2 sec.^-1 since 1963). Among many other projects chemical application of THOR has been one of the important program implimented in early days. Following two projects have been set up with rather limited budget: (1) Production and supply of short-lived radioisotopes (both general purpose and medical use) for domestic use. (2) Application of neutron activation analysis in the fields of environmental, geological, biological and material science. It turned out that quite fruitful results have been obtained. It is the purpose of this paper to describe in detail some of the characteristic aspects on the utilization of THOR in the field of chemical application. (author)

[en] The routine critical loading experiment performed in Tsing Hua Open Pool Reactor (THOR) has been described. In a loading core being very close to critical a dangerous unexpected supercritical effect was observed when the Sb-Be neutron source has been removed from the loading core. The possible reasons for the occurrence of the supercritical phenomenon were discussed. Some conclusions and/or suggestions related to safety issues about critical loading experiment have been drawn. (Author)

[en] The paper presents a computerized monitoring and control system for the THOR. The system is used to assist reactor operation and to facilitate data acquisition and teaching for reactor experimental laboratory courses. The design applies digital data processing for neutron detector and area monitor measurements. Signal validation is used to improve signal reliability. Color pictures in the forms of analog meters, strip charts, and bar graphs are displayed for the control room and for off-site as well. Power control is based on the 'reactivity constraint' approach for wide range adjustment and on-off logics for narrow range regulation. Algorithms are coded in C language and implemented into a 32-bit microcomputer. Evaluations have shown satisfactory results for operation and teaching needs. (author)

[en] The THOR reactor is a pool type 1 MW research reactor and has been operated since 1961. The original MTR fuel elements have been gradually replaced by TRIGA fuel elements since 1977 and the conversion completed in 1987. The calculations were performed for various core configurations by using computer codes, WIMS/CITATION. The computing results have been evaluated and compared with the core measurements after the fuel conversion. The analysis results are in good correspondence with the measurements. (author)

[en] The Feynmann and other fluctuation techniques have been shown to be useful for determining the multiplication of subcritical systems. The moments of the counting distribution from neutron detectors is analyzed to yield the multiplication value. We present the methodology and some selected applications and results and comparisons with Monte Carlo calculations

[en] Taiwan located in the west Pacific, is an island with a 20 million population and an area of 36,000 square kilometers. Island energy resource is meager, endowed only with hydro potential approximately 5,000 MW and limited coal. 95% of primary energy is imported. Island energy policy dictated a need for energy source diversification. By 1994, island electric power system expanded rapidly to 20,983 MW installed capacity. Nuclear power was first started in 1977 and by 1994, three nuclear power stations each with two units totaling 5,144 MW constitute 24.5% of the capacity installed and 30.4% of electric power generated. Nuclear energy has greatly reduced the overall power generation cost during 1980s. Atomic Energy Law aiming at peaceful use of nuclear energy on the island was stipulated in early 1968. Manpower for nuclear planning, design, construction, operation and maintenance has expanded accordingly. For future power demand, a growth of 6% per annum is expected. The fourth nuclear power project was proposed in 1981. However, nuclear accidents at TMI and Chernobyl brought up deep public concerns over nuclear safety. Residents near the nuclear power plant and radioactive waste storage sites expressed strong opposition to the installation. Intensive public relation program was implemented to promote a public acceptance of nuclear power. Most people are convinced that nuclear energy is safe, clean, and economical. To Taiwan, fast growth and rapid change in society brought its side effect with a syndrome of growing pain. We have problems to be faced. Examples are: (1) public concerns to nuclear safety deepened after the TMI and Chernobyl nuclear accidents; and (2) Awareness of democracy and strong sense of environmental protection has created 'NIMB' or 'Not in My Backyard' thinking. (J.P.N.)

No abstract available

No abstract available