Atomic Energy Research Institute Research Articles

Qualification of the ARROTTA Code for Light Water Reactor Accident Analysis

Qualification efforts have been performed by the Taiwan Power Company (TPC) and the Institute of Nuclear Energy Research (INER) for the three-dimensional spatial kinetics code ARROTTA for light water reactor (LWR) core transient analysis. Together TPC and INER started a 5-yr project in 1989 to establish independent capabilities to perform reload design and transient analysis utilizing state-of-the-art computer programs. As part of the effort, the ARROTTA code was chosen to perform multidimensional kinetics calculations such as rod ejection for pressurized water reactors and rod drop for boiling water reactors (BWR). To qualify ARROTTA for evaluation of the Final Safety Analysis Report licensing basis core transients, ARROTTA has been benchmarked for the static core analysis against plant measured data and SIMULATE-3 predictions, and for the kinetic analysis against available benchmark problems. The static calculations compared include critical boron concentration, core power distribution, and control rod worth. The results indicate that ARROTTA predictions match very well with plant measured data and SIMULATE-3 predictions. The kinetic benchmark problems validated include the Nuclear Energy Agency Committee on Reactor Physics rod ejection problem, the three-dimensional Langenbuch-Maurer-Werner LWR rod withdrawal/insertion problem, and the three-dimensional linear regression analysis BWR transient benchmark problem. The results indicate that ARROTTA'smore » accuracy and stability are excellent as compared with other space-time kinetics codes. It is therefore concluded that ARROTTA provides accurate predictions for multidimensional core transients for LWRs.« less

Evaluation of various methods of 99Tcm-human immunoglobulin preparation in scintigraphic detection of infection.

Radiolabelled human immunoglobulin (HIG) scintigraphy has been recognized as a reliable modality for the localization and evaluation of pyogenic infection in humans. Four methods of labelling HIG with 99Tcm developed by the Institute of Nuclear Energy Research of Taiwan are: (1) using ascorbic acid (ASC) for direct labelling of HIG (ASC-HIG); (2) using diethylenetriamine pentaacetate (DTPA) as a bifunctional chelate (DTPA-HIG); (3) using 2-iminothiolane (IM) for modified protein (IM-HIG); (4) using the avidin-biotin system (AVI-BIO-HIG). Our study assessed these four preparations in the scintigraphic detection of infections. Staphylococcus aureus was injected intramuscularly into the left thighs of rabbits. Two days later, when active inflammation developed, 5 mCi 99Tcm-HIG was given intravenously; scintigraphy was performed at 1, 4 and 18 h. The accumulation of 99Tcm DTPA-HIG was the most prominent among the four preparations at the site of infection. It is concluded that 99Tcm labelling of HIG using DTPA as a bifunctional chelate may be the optimal labelling method for detecting infection.

Estimation of Burnup in Taiwan Research Reactor Fuel Pins by Using Nondestructive Techniques

A nondestructive measurement of spent fuel pins from the Taiwan Research Reactor has been performed at the Institute of Nuclear Energy Research. The analysis is based on a simplified balance equation for integrated flux and a series of one-group burnup-dependent microscopic cross-section libraries. A semiempirical test is used for evaluating the burnup values of two different kinds of spent fuel pins [natural uranium (0.7% [sup 235]U) and enriched uranium (7.0 % [sup 235]U)] by the [sup 134]Cs/ [sup 137]Cs activity ratio. Results are compared with radio-chemical burnup measurements. The agreement is within 3.8%, which verifies the accuracy of this method. The results are also compared with a theoretical estimation by the ORIGEN-II code. This indicates that the ORIGEN-II code's library might have an overestimated [sigma][sub a]([sup 133]Cs), which leads to a [sup 134]Cs/[sup 137]Cs ratio that would result in a burnup value [approximately]24 to 35% lower than the measured data.

Thermal-Hydraulic Characteristics of Coolant in the Core Bottom Structure of the High-Temperature Engineering Test Reactor

This paper discusses the high-temperature engineering test reactor (HTTR), a 30-MW (thermal) helium gas-cooled reactor being constructed by the Japan Atomic Energy Research Establishment. A thermal mixing study of the coolant in the core bottom structure (CBS) of the HTTR is conducted to clarify the thermal-hydraulic characteristics of the coolant and estimate the influence of a hot streak on the intermediate heat exchanger (IHX) and a pressurized water cooler (PWC) down-stream from the core. An experiment is carried out using an in-core structure test section (a full-scale simulation model of the (CBS) of the helium engineering demonstration loop (HENDEL), and a numerical analysis is made using a three-dimensional time-dependent flow and heat transfer code including a k-{epsilon} model of turbulence. It is confirmed that the coolant is mixed sufficiently in the CBS and the outlet gas duct of the HTTR, and the hot streak had little effect on the IHX and the PWC.

Studies of the behavior of a reactor neutron beam at the sample position of a diffractometer using silicon monochromators

A computer program TISTA has been developed for calculation of different aspects of designing a double axis neutron spectrometer at the TRIGA Mark II research reactor of the Atomic Energy Research Establishment, Dhaka, Bangladesh. The mathematical algorithms used in this program are based on the formalisms used by Fischer, Sabine and Bacon. Angle and energy resolutions and flux density as functions of neutron wave length, beam collimation, crystal asymmetry and deviation from zero-Bragg-angle position for different silicon crystal planes (111, 220, 311) have been calculated.

Destructive Gamma-Ray Analysis of Fuel Rods from the Taiwan Research Reactor

AbstractDestructive gamma-ray analysis of spent-fuel rods from the Taiwan Research Reactor has been performed at the Institute of Nuclear Energy Research. The purpose of the analysis is twofold: to identify the radioactivities, burnup values, and other essential parameters of spent-fuel rods, and to bridge the gap between the predicted and the actual values. The samples of fuel rods are taken from two kinds of irradiated materials: natural uranium metal and uranium dioxide pellets. Each sample is dissolved in nitric acid and diluted to 100 cm3; the uranium in each of these samples is identified down to the order of 10−10 g/cm3 by mass spectroscopy.A high-resolution, high-purity germanium detector coupled with a multichannel analyzer is used to detect 38 multiscaling gamma spectra within a 160-day period. Radioactivities of the evaluated fission products are compared with data from other works and with calculations using the ORIGEN-II code. Eleven of the 18 fission product values are found to be within 20%...

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A 215 MVA Flywheel Motor-Generator with 4 GJ Discharge Energy for JT-60 Toroidal Field Coil Power Supply System

A 215 MVA flywheel motor-generator is used for the toroidal field coil power supply system of the energy breakeven plasma testing facility, JT-60, which started operations in April, 1985 at JAPAN ATOMIC ENERGY RESEARCH INSTITUTE. This paper describes an outline of the flywheel motor-generator and discusses the determination of the Xd'' value which affects the voltage regulation characteristic of the motor-generator and the twenty-four pulse rectifier circuit, the compensation effect of AVR for the voltage regulation characteristic, the temperature rise and stress of the flywheel which is the largest one in the world and the torsional vibration caused by a thyristor starter, together with the results of field tests.

Study of uranium series disequilibrium in cores of crystalline rocks from URL, Pinawa, Canada: M. Ivanovich, Nuclear Physics Division, Building 7, Atomic Energy Research Establishment, Harwell, Oxon OX11 ORA, U.K.

Study of uranium series disequilibrium in cores of crystalline rocks from URL, Pinawa, Canada: M. Ivanovich, Nuclear Physics Division, Building 7, Atomic Energy Research Establishment, Harwell, Oxon OX11 ORA, U.K.

Chalmers Jack Mackenzie, 10 July 1888 - 26 February 1984

Canada, at the outset of World War II, could not be regarded as an industrialized nation. Wheat, mining and the export of raw materials were still dominant features of the national economy. By the end of five years of war, however, the whole picture had been transformed as a result of Canada’s remarkable wartime industrialization, complementing the contribution of her fighting forces overseas. Lancaster bombers were being produced, fully operational, as well as complete radar sets and a wide variety of war material. Even so specialized a product as optical glass produced to exacting standards was being made in quantity. And a start had been made at the development of the Chalk River atomic energy research establishment on the Ottawa River, to which the top secret nuclear work initiated at Montreal in 1942 was eventually transferred, the beginnings of Atomic Energy of Canada Limited. A vast increase in scientific research and development lay behind these remarkable achievements. As there was little industrial research activity in Canada before the war, at the heart of Canada’s wartime research was the national research organization bearing the somewhat confusing name of National Research Council (N.R.C.). This was a small but active research agency in Ottawa, under the direction of an Honorary Advisory Council on Scientific and Industrial Research. The active leader of this significant organization throughout the critical years of war, and well into the postwar years, is the subject of this memoir, Chalmers Jack Mackenzie.

Target preparation past and present in the United Kingdom

Arising from the growth of the nuclear industry in the late nineteen forties coupled with the increasing availability of electromagnetically separated uranium and stable isotopes the demand increased for targets to study nuclear reactions leading to a better understanding of reactor control, shielding, transport and reprocessing requirements. In 1951 a thin film symposium was sponsored by the Atomic Energy Research Establishment (AERE) Harwell at which criteria and techniques for their preparation were discussed. The preparation of natural, stable, and actinide nuclide targets for the study of nuclear reactions continues to be an important activity in UK laboratories to the present day. The progress of these target preparation activities is reviewed.

Aqueous corrosion of tantalum- and carbon-implanted low carbon steel

The effect of tantalum implantation (5 × 10 16–10 17 ions cm −2; 80–150 keV) on the electrochemical behaviour of a low carbon steel in an acetate buffer solution of pH 5.6 has been investigated. Samples had been irradiated in the 300 keV accelerator at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt, and in the Cockcroft-Walton implantation machine at the Atomic Energy Research Establishment (AERE), Harwell. Tantalum-implanted specimens produced at GSI yielded potentiokinetic polarization curves similar to those obtained earlier for chromium-implanted iron with respect to the hydrogen evolution kinetics, the critical current densities required for passivation and the passive current densities. All effects were more pronounced after implantation of higher doses of tantalum. Successive sweeps indicated the possibility of preferential (selective) dissolution of iron. Tantalum implantations carried out at AERE repeatedly resulted in specimens with differently coloured surfaces, which then showed a much stronger inhibition of anodic as well as cathodic reaction kinetics. Implantations with Ti + and W + ions gave similar results. Carbon analysis using Auger electron spectroscopy and the 12C(d, p) nuclear reaction method showed the presence of carbon layers a few tens of nanometres thick on these samples. Further experiments carried out in an attempt to explain the above phenomena were (a) pre-implantation surface contamination with organic compounds, (b) successive bombardment with Ta +, C + and O + ions, (c) implantation of tantalum in residual gas atmospheres containing organic compounds and CO 2, and (d) implantation of tantalum into carbon (or hydrocarbon) layers deposited onto steel. The results of these experiments illustrate the marked difference between the corrosion behaviour of samples enriched in bulk carbon and the corrosion behaviour of samples with surface layers containing carbon.

The analysis of the activation energies for self-made TLD-CaSo4:Dy

Abstract In this paper we study the activation energy for TLD-CaSO4:Dy which was fabricated by the Institute of Nuclear Energy Research. Two different methods have been used to determine the activation energy. The methods used were (1) the glow curve shape analysis method which contain four different equations, and (2) the variable heating rate method. The average activation energy values determined by glow curve shape analysis method are about 0.87 eV. The variable heating rate method shows the activation energy having a value of 1.19 eV. The symmetry factor, μ, is 0.52 and the kinetic order is 1.88. The results are compared with those obtained by other authors.

The Neutron and its Applications

The 50th anniversary of the discovery of the neutron by Sir James Chadwick is being marked by a major conference to be held at Cambridge on 13–17 September. The conference will take place under the title The neutron and its applications' and is being organised by The Institute of Physics in collaboration with the Atomic Energy Research Establishment, Harwell.

Spectrographic Determination of Common Impurity Elements in High-Purity Lanthanum Oxide

An emission spectrographic method for the quantitative determination of 17 trace elements in high-purity lanthanum oxide has been developed. The sample was ignited in muffle furnace at 850° for one hour to remove the moisture and carbon dioxide, then blended with equal amount of graphite and 10 mgs of this mixture was taken into electrodes. A 10 amps dc are was employed to excite the mixture and a 3.4 meter Ebert Spectrograph with 15,000 LPI plane grating was used to record the spectrum in the region 2,200 at 3,400 Å. The weak line of lanthanum was used as an internal standard. The working ranges of these elements were: Ag, Mg 0.5 to 50 ppm; Be 0.5 to 100 ppm; V, Cr 1 to 100 ppm; Cu, Sn, Fe 3 to 100 ppm; Ge, Mn, Ni 5 to 100 ppm; B, Co, Pb, Sb 10 to 100 ppm; Ca and Si 30 to 500 ppm. The precisions fell in the range of 10 to 24%. Samples obtained from Engineering Research Laboratory (ERL) of Institute of Nuclear Energy Research were also examined.

Invited review article ordering of voids and gas bubbles in radiation environments

Abstract Dr. Kanwar Krishan graduated from Panjab University, Chandigarh and did his doctorate from the Indian Institute of Technology, Kanpur in 1971. He was subsequently a Visiting Fellow at the Tata Institute of Fundamental Research, Bombay where his research interests were in magnetism and defects in solids. In 1972 he joined the Bhabha Atomic Research Centre, Trombay and later spent a year as a Visiting Scientist at the Theoretical Physics Division, Atomic Energy Research Establishment, Harwell where he worked on problems relating to void swelling in metals. From 1975 onwards he has been at the Reactor Research Centre, Kalpakkam as Head of the Radiation Damage and Defect Studies Group in the Materials Science Laboratory. His current interests are in radiation damage, phase instabilities in metals induced by irradiation, metallic glasses and computer simulation applied to defects in solids.

Nuclear Grout Monitoring on Offshore Platforms

Summary Over the last 4 years, the Atomic Energy Research Establishment (AERE) at Harwell, England, has developed nuclear instrumentation and tracer techniques to measure the density and movement of grout used in the installation of steel jackets to the seabed. These methods have been applied to a number of steel jackets in the North and Celtic seas where weather conditions can affect greatly the application of traditional methods of visual inspection. Introduction Radioisotope density gauges capable of indicating the presence and accurately measuring the density of cement grout during and immediately after grouting of sleeve/pile annuli have been developed by AERE. They have been used successfully on a number of structures in the North and Celtic seas and since 1979 have been produced and used by Wimpey Laboratories Ltd. under license. These instruments, of a type well-established in a wide variety of industries, have been developed for subsea operation at depths exceeding 1,640 ft (500 m). Nuclear gauges also have been used for control at the grout mixing plant, thus enabling more constant grout densities to plant, thus enabling more constant grout densities to be achieved during pumping operations. Radioisotope tracers have been used for a considerable time for a number of types of investigations in oilwell drilling and logging. One such method has been used to monitor the movement of grout around the outside of insert piles of a structure. This method used powdered glass, size-matched to the cement and containing Scandium 46, which is introduced into the grout, and its progress up the outside of the pile is monitored by means of radiation detectors suspended within the insert pile. Grout Density Measurement Description of Gauges The grout density gauges are based on measurement of the decrease in intensity of a beam of gamma radiation after passing through grout as it flows between a radioactive source and radiation detector. Typical gauge arrangements are shown in Figs. 1 and 2. Calibration of the gauge gives the following relationship for the density of grout. I Pg =Pref -A 1n --,.................................(1) Pg =Pref -A 1n --,.................................(1) B where I is the ratio of gamma radiations passing through grout and water, respectively, and A and B are calibration constants. In practice, it is convenient to use seawater as the reference fluid since the measurement of count rate can be made in situ, with constant geometry of the gauge to the surrounding steel structure, and immediately before grouting commences. A typical calibration curve is shown in Fig. 3. The gauges used on offshore platforms have included sources of either Caesium 137 [half-life of 30 years and gamma energy of 0.66 MeV (0.1 pJ)] or Iridium 192 [half-life of 74 days and gamma energies of 0.3 to 0.6 MeV (0.05 to 0.1 pJ)]. The latter isotope, although of a weaker and marginally more favorable gamma energy for this application, has the disadvantage of a relatively short half-life if major construction holdups delay float out or installation of the structure. The radiation detector, a geiger counter specially constructed in a waterproof housing, has been tested to withstand shock loads of up to 300 g (3000 m/s 2), hydraulic pressure tests at more than 1,640 ft (500 m) of head for periods of several weeks, vibration tests over a wide frequency range at accelerations of up to 15 g (147 m/s2), and over a 40 degrees C temperature range. JPT P. 425

COATING RESEARCH AT HARWELL

Two new particle coating methods—the Sol‐Spray and Planetary Rolling techniques—for use in metallurgical applications have been developed at Atomic Energy Research Establishment Harwell.

Food irradiation studies at the Institute of Nuclear Energy Research, Taiwan, Rep. of China

The use of radiation to inhibit sprouting of potatoes, onions, gingers and garlic was studied at the Institute of Nuclear Energy Research. The sprout inhibition doses of potatoes, onions, gingers and garlic were found to be 10, 5, 2.5, 7.5 Krads, respectively. Changes in the content of moisture, ash, reducing sugars, total sugars, lipids, proteins, fiber etc. were monitored in various agricultural foodstuffs both with and without γ-irradiation at various doses. Fungicides did not prevent potatoes from decaying at 10 or 25°C with or without gamma radiation. Onions treated with any of fungicides has significantly more healthy tissues than controls at 10°C but not 25°C after 30 and 60 days storage, regardless of the presence or absence of gamma radiation. Insect pests have been causing great damage to stored rice in Taiwan. The four most harmful insects are: Sitophilus Zeamais Mostschulsky. Rhyzopertha dominica. Tribolitum custaneum Herbst and Sitotroga cerealella Oliver. Adults, eggs or larvae of these insect pests were irradiated by 60Co gamma rays. The results show that 40 Krads of gamma-irradiation could completely control these four species of pests in stored rice.