Developments
Electricity supply system to provide training in the protection of instruments
Power conditioning is crucial for a proper functioning of nuclear and related instruments
in developing countries. About half of the damages in the instruments is caused by the disturbances
in the electric mains supply,
and therefore training in this field is becoming inevitable.
To transfer the know-how an electricity supply system has been designed to demonstrate different
electrical supplies and grounding systems as well as the principles of protection. A number of
relevant exercises for training has been developed and completed with the assistance of
Ms. Phyu Phyu Thein from Myanmar during her fellowship.
Temperature Recorder for computerized long-term automatic temperature logging
The design realized at the Instrumentation Unit is an integrated temperature recorder which
is not only capable of working as data-logger (for temperature measurements only) but also of
histogram tabulation (number of discrete measurements) taken within the temperature range of -40ēC to +85ēC.
Its on-chip Real Time Clock (RTC) counts seconds, minutes, hours, days, months, days of the week and years,
and is aware of leap years. The temperature recorder may be programmed to any alarm time you want within one week.
When the alarm is reached an interrupt is generated. The temperature recorder allows you to program
measurement intervals ranging from 1 to 255 minutes. This applies to both measurement modes. The nonvolatile
measurement data memory has a capacity of 2048 samples, including start time marker ("time stamp") when used
as a data logger, or data bins in 2ēC increments when the histogram mode is selected. Each of these data bins
is capable of recording 25,535 measurements. High and low temperature trip points may be programmed at which
an alarm condition is generated. The data logger can be connected to a host PC via its serial interface, capable
of asynchronous operation. The software provided allows easy set-up and configuring of the data-logger as well
as retrieving and displaying the recorded data. The command to start measuring can either arrive via the serial
interface or through an external switch. As the temperature recorder is built into a hermetically sealed box,
the start signal is applied through a magnetic switch. The temperature recorder can serve in two primary
applications. First, it provides most of the functions necessary for a stand-alone portable data-logger.
Portable data-loggers are often used for monitoring perishable products in transit, environmental research,
and numerous other applications. As a second type of application, it can be attached to a system whose
primary function is something other than monitoring. Systems often benefit from environmental monitoring
to ensure reliable operation. This information can be useful for calibration, maintenance, and warranty information.
Remote Controlled Data Logger for Environmental Parameters
It is a stand-alone system based on the 80C537 micro-controller. It allows storage of data coming from
various sensors into its serial EEPROM. Communication and remote control can be done using whether an external
modem using normal telephone lines or a dual-band GSM modem. The option to be used depends on the availability
of the communication media. The RECODAL has four types of memories ROM, RAM, EEPROM and SERIAL EEPROM. RAM and
Serial EEPROM are configured as non-volatile memory for data storage. The overall idea was to design a compact,
reliable, flexible and easy extendable system. RECODAL is robust enough to be used under harsh environmental
conditions. Therefore all external parts have been selected to be water proofed and hermetically sealed RECODAL
has been designed to be supplied by solar power and/or mains power (220 VAC). It has to be mentioned that the
firmware can be upgraded remotely via telephone without affecting the data or the communication program .
This project has been realized by fellows from Egypt and Madagascar who received training in design of
micro-controller based equipment.
Temperature control unit for a Co-60 gamma irradiation cell
The calibration has to be carried out in a Co-60 Gamma cell irradiator at different stable and controlled
temperature. The range of the temperature is from 0.0 to 50.0 ēC, resolution and stability is 0.1 ēC. The duration
of the irradiation is rather long (sometimes days). Many dosimeters are placed in the chamber and irradiated
simultaneously; the temperature of the whole volume of the chamber should be uniform and controlled. Because of the
high gamma fields and a high risk of damages for transistors and integrated circuits, no semiconductor electronic
component can be used inside the chamber. The system consists of three units (i) cooling/heating head located in the
Co-60 Gamma cell chamber, (ii) electronic temperature controller unit and (iii) container for cooling water with pump.
High precision reference current-source (RCS-01)
The RCS-01 (Reference Current-Source) is a battery operated high precision electronic current-source. It supplies a
stable electric current (50 pA nominal), which can be measured with most of the electrometers applied for the ionization
current measurements. This unit is used only to check (not to calibrate) the electrometers. The output current is generated
by applying the voltage from a very high precision voltage reference across a megistor. A temperature dependence of this
megistor has to be taken into account and its temperature is displayed on an LCD of the built-in thermometer. Using a proper
cable adapter the current source can be connected to most modern electrometers used for ionization current measurements.
The medfly pupae sorter
The sterile insect technique (SIT) is a biological method of eradicating or controlling insect pests. It has been
successfully used in many parts of the world against, e.g., the Mediterranean fruit fly in Chile, Mexico and California,
and the New World Screw Worm in Libya and Central America. The medfly pupae sorter was developed by the IU to
sort a sample of the pupae according to their colour (brown and white for male and female, respectively) and to count
them for further evaluation. The medfly pupae sorter consists of the electromechanical unit and a portable compressor
for the sorting process. A reasonable quantity (max. 1000) of pupae is poured into the bowl feeder tray. The pupae are
slowly moving to the rim of the feeder where a sensor measures their colour and activate an air jet blowing the white
pupae aside. The brown and white pupae are collected separately and counted; the total counts are displayed on the
front panel. The medfly pupae sorter is used at the Laboratory for Quality Control of the sterile insect technique.
Sample changer and detector positioning system for Neutron Activation Analysis
The sample changer picks up the samples from a storage compartment, capable to hold up to 100 samples. It carries the
samples over a distance of 2.5 m before they are placed in a rotating sample holder in front of the detector. The
measurement chamber shielded with lead is then automatically closed and the measurement is started. When the
measurement is finished the sample is automatically exchanged. The whole process is controlled by a micro-controller
and a special software which allows the operator to preset different measurement parameters. Integrated control functions
and cross checks guarantee that no sample is lost on its way. On-line information keeps the operator continuously
informed about the current status of the system and allows to correct problems in case an error is reported.
Fluxer control device
A gas sensor, located at the bottom of the internal part of a fluxer directly below the burners, and one temperature
sensor located above the fluxer in the fume-cupboard cut the gas flow in case of anomaly; moreover, in order to ensure
the permanent attendance of the melting session by the operator, a two minute cycle presence detector with press button
and tone alarm is provided, ensuring a complete shut down in case of no reset of the alarm within 15 seconds; it goes
without saying that the entire system provides no power-no gas logic.
Light weight mechanical hoist for CANDU Bundle Verifiers
For positioning of different collimators (max 80kg) in the storing pool of reactors. The hoist moves the
collimator-detector assembly at constant speed (0.1 - 100 mm/sec) vertically while a spectroscopy system collects
spectra's about the stored fuel rods.
A new growth chamber concept
As in developing countries provision of electrical power is a general problem, the idea to build a plant growth
chamber completely independent from external electrical power was born. Until now the plant growth is stimulated by
using artificial light coming from special fluorescent lamps (40 lamps of 36W each = 1.5kW) that produced an illuminance
of 3000Lux. To abolish the heat generated by these lamps and to keep the room temperature within certain limits (~25ēC),
AC systems (2-3kW) had to be used additionally. In all of the countries in question, sun is available most time of the
year and could therefore be used as an alternate source to produce electrical power. Unfortunately it is an unrealistic
approach and too expensive, to produce the needed electrical power only by using photovoltaic cells together with buffer
batteries. Additional the technique used, should be easy to be transferred and easy maintainable. A more realistic
approach using natural sunlight to illuminate the growth chamber has been already realized in an experimental setup.
Using methods of coupling sunlight into the chamber without too high heating components resulted in a drastic decrease
of the overall power consumption.
Remote controlled Video-Camera Trolley
The video camera trolley was designed to allow control of seals in high radiating areas as in dry fuel storage compartments.
The whole design is based on commercial available components as used in modeling. The trolley can move forward and backward
in left and right direction. The video camera is mounted on a telescope that can be expanded up to 2m manually.
The video camera itself can be remotely moved to any angle, max. 45° from the straight forward position. The system is
entirely powered by rechargeable batteries and can operate up to two hours.