KUALA LUMPUR: A scientist explains what exactly is an Industrial Radiography Equipment and why such a Radioactive Dispersal Device (RDD) could lead to dire consequences if it falls into the wrong hands.
Madani NDT Training Centre managing director Dr Abd Nassir Ibrahim said the equipment was used heavily in various engineering projects, including in the construction and maintenance of power plants, chemical and petrochemical plants, and automobiles factories.
The metallurgy expert said the equipment was used for testing engineering components to detect the presence of dangerous and invisible defects that might exist.
Dr Abd Nassir Ibrahim
“As an example, a weld in a boiler may contain cracks that are hidden and cannot be seen by human eyes.
“The presence of such defects if not detected may result in an explosion when the boiler is put into operation.
“Radiography is proven to be a method that has the capability to detect such a crack.”
Nassir said cracks in a weld — boiler, pressure vessel, piping and other components — had a tendency to grow and cause explosions that could lead to loss of life, as well as causing fire and serious destruction to industrial plants in which those components operate.
He cited an explosion back in 2014 in Lawas, Sabah. The explosion was a result of a failure to detect a weld pipe due to a landslide.
The incident led to the displacement of nearly 1,000 people in the area.
Nassir said by virtue of the deadly consequence of such accidents, the use of radiography testing had been made mandatory in the manufacturing and construction of critical engineering components and structures throughout the world, including in Malaysia.
However, he said, despite the many advantages the radiography method offers, it employed extremely radioactive material as a source of energy that was required to penetrate the tested objects.
He said the material emitted high-energy ionising radiation — the gamma ray.
“High-energy gamma rays traverse through and are modified by the internal structure of material. If the tested material contains cracks or other serious defects, the gamma rays will be modified accordingly through a process known as a differential absorption.
“After passing through the material, the remaining radiation exits from the material and is recorded in a radiography film. The film is processed and at the end of this process an image of cracks will appear on the film.”
Nassir said gamma rays emitted by a radioactive material used for industrial radiography had “extremely high-energies” and present a great potential for causing destruction to human cells exposed to it.
This fact that such exposure could lead to serious consequences, such as radiation burns, development of cancer and cataract, is why the application is strictly regulated by the Atomic Energy Licensing Board (AELB).
“Rules and regulations stipulated by AELB require radiography workers to attend a course, followed by an examination and only if the person passes can he be considered for certification and recognition after acquiring sufficient practical experience for a specified period of time,” said Nassir, who is also Malaysian Society for Non-destructive Testing president.
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