The RDD is a non-nuclear industrial radiography equipment containing the radioactive isotope Iridium-192 that emits beta and gamma radiation. — AFP pic

KUALA LUMPUR, Aug 23 — An area as large as 1.3 square kilometres could be exposed to dangerous and mutagenic radiation if a stolen radioactive dispersal device (RDD) is unsheathed in the open, said a metallurgy expert.

Mandani Nondestructive Training Centre managing director Dr Abd Nassir Ibrahim told Malay Mail that based on the active material contained in the 23kg RDD, unsupervised opening of the item would leave those in the area in danger of non-treatable exposure.

Based on an estimation that the contained isotope could have a strength of 1,750 gigaBecquerel (gBp), which denotes the activity of the radiation upon exposure, improper excision in an urban centre could expose an area of about 660 sq km.

The exposure will be less if the device is opened indoors, but will be magnified if this is done in a completely open region.

“In this case, if the source is somewhere around a highway and naked, the affected area will have a 660m radius or 1.32km area centred at the source,” he predicted.

However, the strength of the radiation from the device could be as high as 3,000 gBp. For comparison, a modern nuclear warhead emits around 15,000 gBP upon impact, according to the “Nuclear Disaster” book by Alex Wolf.

Radioactive equipment and materials are particularly risky as there are no outward clues about their possible radiation risks, and unsuspecting scrap metal dealers or members of the public are unlikely to be able to identify their dangers.

“Those who are trained can recognise it, (but) to the layman, it may just be a heavy industry equipment that may be worth selling as scrap metal,” he told Malay Mail.

With police having ruled out terrorism as a possible motive for the device’s theft, the fear now is that it will simply be abandoned given the current high-profile of the incident.

Abd Nassir explained that the danger could then be if an unsuspecting person comes across the device and opts to open it out of curiosity.

“If this happens, it will pose a great danger to members of public,” the metallurgist warned.

While declining to comment on the investigation, Abd Nassir explained that another danger of radiation exposure is that it can only be corroborated through blood tests, and even then, only when specific tests are applied.

Once detected, there may also not be a sure way to reverse or neutralise the radiation.

The RDD is a non-nuclear industrial radiography equipment containing the radioactive isotope Iridium-192 that emits beta and gamma radiation.

Sheathed within the protective outer layer of the RDD, the radioactive material is contained in a stainless steel “tablet” about 1mm in diameter, Abd Nassir explained.

The active material emits ionic radiation that is used to trace defects such as hairline cracks imperceptible to the human eye when used to scan items such as welding joints and surfaces.

Abd Nassir noted that prior to this case, there was another in February 2017 when thieves stole two Delta 880 industrial radiography projectors from a car outside the office of a company that services and maintains pipelines for oil-and-gas firms.

It was reported that that the Atomic Energy Licensing Board’s (AELB) radioactive regulatory division alerted residents in the apartment area that they may have been exposed to radiation as the thieves had cut open the casings of the equipment.

Due to the high risks and dangers involved in dealing with radiation, he said radiographers are required by law to be thoroughly trained and certified in accordance to a Malaysian Standard that is derived from the ISO Standard.

The intensive training covers the technicalities of industrial radiography, usage of the projectors as well as advanced safety procedures related to its operation.

“The projector alone is also considered a controlled item as it contains a quantity of depleted uranium in it,” he added.

He said that as of 2015, there were 21,000 trained radiation workers in Malaysia, and about 6 per cent of whom were specialist in industrial radiography; the rest were mostly in other industrial and medical fields.

Despite the number, he said few among these work directly with high energy devices or directly with radioactive sources.

Those who do are experts trained and responsible for dealing with radiation-related emergencies, he added.

Abd Nassir, who is now retired from the Malaysian Nuclear Agency, currently runs a centre in Bandar Baru Bangi that provides trainings in the field of industrial radiography as well as radiation awareness courses for members of public and radiation workers.

He works closely with SIRIM and Malaysian Nuclear Agency on the courses.

“For anyone who want to become an industrial radiographer, the guidelines and process is tough and not many make it,” he said adding that refresher courses are also held for radiation protection supervisors and radiation protection officers who wish to renew their knowledge.

The RDD was reported stolen on August 10, after which police arrested two technicians at the company from which the device was stolen.

Both men were later released for lack of evidence and investigations are ongoing.