Building a Home for Radioactive Waste in the Dominican Republic

Sierra Prieta, Dominican Republic — While the Dominican Republic generates a relatively low volume of radioactive waste, it has prioritized their safe and secure treatment.

Radioactive sources are used in fields such as medicine, industry and mining. Once they have served their purpose, such so-called disused sources must be safely and securely stored or disposed of because they may pose hazards to public safety, the environment and to national security. Protecting the public and making sure that radioactive material does not fall into the hands of criminals are, therefore, a priority for the government, said Vice-minister of Energy and Mines María de los Ángeles Peña.

Any disused radioactive source identified in the country is transported, characterized, classified, conditioned and stored in a centralized facility built in 2010 in Sierra Prieta, outside the capital Santo Domingo. The amount of time the sources are kept in this safe and secure storage can range from a few years to up to 50 years, depending on their level of activity and the period for which they remain radioactive.

“All radioactive sources that are no longer usable end up in the storage facility,” Ángeles Peña said. “We do this to ensure not only nuclear safety, but also nuclear security, which we take very seriously.”

The facility is vigorously protected with fences and guards and constantly monitored with cameras. An armed military guard is present round the clock. The facility is equipped with radiation detectors provided by the IAEA. A team of professional staff trained under IAEA technical cooperation projects is in charge of the operation, maintenance and regular inspection of the storage facility.

Around 170 sources from applications in hospitals and industry as well as so-called orphan sources — radioactive sources that are lost and then found again — detected in scrap metal industries have found a home in the facility. Some are high-activity sources, meaning they emit high levels of radiation, such as those used in radiotherapy to treat cancer. Others are low-activity sources, such as those used for industrial and research applications.

“Radiotherapy can do wonderful things,” said Luis Morilla, the engineer responsible for the operations of the storage facility. “If you look at brachytherapy, for example, you see how well it can treat cervical cancer. But after a while, once these sources are no longer usable, hospitals need to dispose of them. And nobody wants to keep them; nobody wants anything to do with waste.”

Other disused sources come from mining, agriculture and construction. Gold processors, for example, use radiotracers — chemical compounds containing radioisotopes that emit radiation — to study flow patterns. Since the Dominican Republic has the biggest gold mines in Latin America and the Caribbean, many sources come from this industry.

Spreading the word

The work of the staff at the facility goes beyond storing disused sources, Morilla added. “The key here is that we’ve established a network of professionals all around the country and across multiple disciplines,” he said, to spread the knowledge about the importance of handling radioactive material safely and securely.

In 2013, the National Energy Commission established a network for the safe and secure transport of radioactive materials. As a result, professionals from all relevant disciplines regularly meet to exchange information.

The network connects government officials, police and customs officers, emergency preparedness and response professionals, nuclear regulators, transport officials and port and airport staff. Its aim is to prepare all relevant stakeholders to respond to an emergency. Under the network, the National Energy Commission coordinates training courses in nuclear safety and security and organizes emergency preparedness and response exercises.

“The idea is to apply the safety standards and security guidance we learn from the IAEA to all areas in which radioactive sources are used across the country, even before disposal,” Ángeles Peña said. In the past two years, they have trained more than 30 experts in nuclear technology, safety and security through IAEA expert missions and fellowships, she added.

In line with the radioactive waste management national strategy, Dominican authorities don’t expect to store large volumes of sources in the future. “Our first option is to give radioactive sources back to those who provided them,” Morilla said. “But some sources cannot be repatriated. We have historical sources and donated sources, for example, that we just can’t give back.”

IAEA Impact: Increasing Safety in Radioactive Waste Management

Although the practice of dumping radioactive waste into the oceans disappeared in the early 1990s, materials containing minimal levels of radioactivity are still allowed and regulated. Rules for dumping this type of materials into the oceans have become stricter following the adoption of an IAEA methodology aimed at protecting not only humans, but also the marine environment.

In a meeting held from 12 to 16 October in London, representatives of 87 countries agreed to set more specific thresholds on materials for dumping at sea. The venue was the 37th annual gathering of countries which are parties to the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, also known as the London Convention.

“This recently updated methodology includes a radiological procedure used to ensure not only the protection of humans, as in the past, but also the explicit protection of marine flora and fauna,” said Diego Telleria, Radiation Protection Specialist at the IAEA.

As described in the IAEA’s January 2015 publication, the concept, called de minimis, only allows dumping at sea of materials that are non-radioactive or cause such negligible impact to humans and marine organisms that it is of no regulatory concern.

To define the thresholds, IAEA experts used a dose that all marine organisms can tolerate, said Telleria. To do this, they considered three marine reference animals and plants which are the most prone to be exposed to radiation —flatfish, crab and brown seaweed— and established the maximum acceptable concentration of radioactivity based on these species’ level of tolerance.

The 2003 guidelines on the application of de minimis, published by the International Maritime Organization (IMO), will be updated to incorporate this new methodology. The actual thresholds will not change as a result of the update to the regulations, as the calculations revealed that the limits set for humans had also in effect already protected the environment. “At the request of parties to the Convention and addressing the concerns of environmental groups, the protection of flora and fauna has now been made explicit,” Telleria said.

Inventory of Radioactive Waste Dumping

The IAEA has acted as the technical advisor on radioactive matters to the Convention for more than 40 years. This month, it published a comprehensive inventory of human-made radioactive sources entering the ocean since 1946.

Developed by the IAEA in cooperation with the IMO, the ‘Inventory of Radioactive Material Resulting from Historical Dumping Accidents and Losses at Sea’ compiles past waste dumping, accidents and losses at sea involving radioactive material recorded since the 1940s and 1950s up until 2015.

The inventory will serve as the official record for the London Convention and help scientists to evaluate the impact of radionuclide sources in the marine environment anywhere in the world, Telleria said.  

The IAEA periodically gathers information from its Member States to track the amount of radioactive materials that have entered the world’s oceans and seas and assesses their loss of radiation, or radioactive decay, over time.