[en] A subchannel analysis code MATRA has been developed for the thermal hydraulic analysis of SMART core. The governing equations and important models were established, and validation calculations have been performed for subchannel flow and enthalpy distributions in rod bundles under steady-state conditions. The governing equations of the MATRA were on the basis of integral balance equation of the two-phase mixture. The effects of non-homogeneous and non-equilibrium states were considered by employing the subcooled boiling model and the phasic slip model. Solution scheme and main structure of the MATRA code, as well as the difference of MATRA and COBRA-IV-I codes, were summarized. Eight different test data sets were employed for the validation of the MATRA code. The collected data consisted of single-phase subchannel flow and temperature distribution data, single-phase inlet flow maldistribution data, single-phase partial flow blockage data, and two-phase subchannel flow and enthalpy distribution data. The prediction accuracy as well as the limitation of the MATRA code was evaluated from this analysis

[en] As one of the detailed action strategy of multi object preparedness for strengthening of radiation safety management by MOST, this project was performed, in order to promote the safety culture for user and radiation worker through effective education program. For the prevention of radiological accident and effective implementation of radiation safety education and training, this project has been carried out the development of education model and its evaluation system on radiation safety. In the development of new education model, education course was classified; new and old radiation worker, temporary worker, lecturer and manager. The education model includes the contents of expanding the education opportunity and workplace training. In the development of evaluation system, the recognition criteria for commission-education institute and inside-education institute which should establish by law were suggested for evaluation program. The recognition criteria contains classification, student, method, facilities, teaching material of education course. Furthermore, the education program of employer was introduced for the purpose of promoting the safety mind of employer

[en] As nuclear industry in Korea is being expended, the number of user for radioisotope and radiation generators has being remarkably increased. As a result, radiation shielding problem for radiation safety has raised as a question of great interest nowadays. In this report, gamma scanning test (GST), one of the nondestructive test methods of radiation shielding material was introduced and the review of the test method and its application were described. In addition for accurate evaluation of the test result, necessary basic equipment for the test and for improvement of the equipment were suggested. If the effective test method described above were widely and properly applied by GST related companies, the technology would be used effectively, as one of the safe nondestructive test for radiation shielding material in future

[en] One of the important things in low level radioactivity measurement is determination of the optimized counting time. Counting strategy has to be established, in order to count the radioactivity of the sample by condition of optimized measurement. There were three kinds of counting strategies in this report; about fixed time, about fixed count, to compared sample, background, and reference level. The best of them was satisfied condition to give about condition of instrument and process, as an example, efficiency of detector, counter capacity, maximum and average background count rate of counter, reference level and limit of decision and detection, etc. Therefore, we can decide the optimized counting time in the screening and monitoring. And we can save the time for counting the sample of course the data of count will be counted by optimized accuracy. Finally, in routine measurement of radioactivity these strategies will be used available

[en] Subchannel analysis code plays an essential role for the thermal hydraulic design of PWR cores. It calculates subchannel-wise local properties under single- and two-phase flow conditions which are used as input parameters for evaluating design parameters such as minimum DNBR and maximum fuel temperature. A validation system for subchannel analysis codes for steady-state conditions is provided in this study through investigation of validation status of existing subchannel codes, review of licensing guideline for thermal-hydraulic codes, and establishment of thermal hydraulic data base for test bundles. Thermal hydraulic test data has been procured for the following experiments: CNEN 4x4 flow distribution test, CU 4x4 flow and enthalpy distribution test, PNL 7x7 flow blockage test, GE 3x3 two-phase flow and quality distribution test, CE 15x15 inlet jetting test, WH 14x14 inlet blockage test, PNL 2x6 low flow test, ISPRA 4x4 two-phase flow and quality distribution test, FRIGG 36-rod void distribution test, Zion-1 plant FA exit temperature distribution test. Sampling analysis for each test has been conducted by employing KAERI inhouse subchannel analysis code MATRA. The state-of-the-art for subchannel thermal hydraulic analysis models such as void fraction correlations, crossflow and turbulent mixing models, and heat transfer correlations was also investigated

[en] From HPGe calibration spectrum of liquid mixed source in cylindrical vial, we developed simulated spectrum for spectrum analysis education. It is the spectrum that combine peaks separated from measured spectrum. After that, spectrum removed statistical variation of channel counts. Statistical fluctuation of the spectrum is made by Box-Muller function. The spectrum contains 18 peaks. The peak's centroid and area were defined exactly. Developed spectra are calibration spectrum, sample spectrum, background spectrum and spectra for efficiency correction for geometry and cascade coincidence

[en] The objective of this project is to implement a fast-running 4-channel based code CETOP-D in an advanced reactor core protection calculator system(RCOPS). The part required for the on-line calculation of DNBR were extracted from the source of the CETOP-D code based on analysis of the CETOP-D code. The CETOP-D code was revised to maintain the input and output variables which are the same as in CPC DNBR module. Since the DNBR module performs a complex calculation, it is divided into sub-modules per major calculation step. The functional design requirements for the DNBR module is documented and the values of the database(DB) constants were decided. This project also developed a Fortran module(BEST) of the RCOPS Fortran Simulator and a computer code RCOPS-SDNBR to independently calculate DNBR. A test was also conducted to verify the functional design and DB of thermal-hydraulic model which is necessary to calculate the DNBR on-line in RCOPS. The DNBR margin is expected to increase by 2%-3% once the CETOP-D code is used to calculate the RCOPS DNBR. It should be noted that the final DNBR margin improvement could be determined in the future based on overall uncertainty analysis of the RCOPS

[en] The objective of this project is to verify the thermal-hydraulic model for advanced reactor core protection system, RCOPS. This project compared the RCOPS DNBR module(STATIC) against the CETOP-D code because the RCOPS DNBR algorithm is the same as the CETOP-D. The RCOPS STATIC module and its database was verified by comparing the STATIC DNBR with the CETOP-D DNBR which was calculated at various core operating conditions. In order to get an approval of KINS on Topical Report, the TR on the improved functional designs in the core protection calculator system was submitted to KINS. Module test and Unit test were performed to verify and validate the RCOPS on-line software. The RCOPS DNBR margin was predicted by estimating the overall DNBR uncertainty for UCN 4 cycle 10. The RCOPS TR on the CPCS algorithm improvements was approved by KINS. The simplified module test of the RCOPS DNBR module was passed by satisfying the acceptance criteria. The minimum DNBR(MDNBR) of the RCOPS appeared to be 0.3%-1.0% higher than the CPCS MDNBR at a typical core operating condition

[en] High quality radiation dosimetry is essential for workers who rely upon personal dosemeters to record the amount of radiation to which they are exposed. The ministry of science and technology (MOST) issued a ministerial ordinance (No 199-15) about the technical criteria on personnel dosimeter processors on 1992. The purpose of this quality control program is to prescribe the procedures approved by the management of KAERI for implementing a quality badge service by means of TLD for personnel working in an area where they may be exposed to ionization radiation. (Author) 10 refs

[en] The thermal neutron cross-sections for the ¹⁶⁴Dy(n,γ)¹⁶⁵Dy and the ¹⁸⁰Hf(n,γ)¹⁸¹Hf reactions have been measured by the activation method at the heavy water thermal neutron facility of the Kyoto University Reactor, KUR. The results measured at 0.0253 eV are 2656±98 b for the ¹⁶⁴Dy(n,γ)¹⁶⁵Dy reaction and 13.04±0.47 b for the ¹⁸⁰Hf(n,γ)¹⁸¹Hf reaction, respectively. The results have been obtained relative to the reference value of 98.65±0.09 b for the ¹⁹⁷Au(n,γ) ¹⁹⁸Au reaction. For dysprosium, most of the experimental data and the evaluated ones in ENDF/B-VI and JEF-2.2 are in good agreement with the present value. For hafnium, the previous measurements and the evaluated ones in ENDF/B-VI and JENDL-3.2 are in good agreement with the present result. The resonance integrals for the ¹⁶⁴Dy(n,γ)¹⁶⁵Dy and the ¹⁸⁰Hf(n,γ)¹⁸¹Hf reactions have also been measured relative to the reference value of 1550±28 b for the ¹⁹⁷Au(n,γ)¹⁹⁸Au reaction using a 1/E standard neutron spectrum field of the Kinki University Reactor, UTR-KINKI. The present resonance integral for the ¹⁶⁴Dy(n,γ)¹⁶⁵Dy reaction is 649±24 b, and the existing experimental and the evaluated data are distributed from 335 to 820 b. The present result for the ¹⁸⁰Hf(n,γ)¹⁸¹Hf reaction is 32.4±1.2 b, and most of the previous measurements and the evaluated values are close to the present measurement. Gryntakis et al. reported the resonance integrals for both reactions, whose results were also in good agreement with the measurements