Cobalt-60: Investing for the Future of Gamma Sterilization

On 27th June 2023 Nordion (a Sotera Health company) held their webinar ‘Cobalt-60: Investing for the Future of Gamma Sterilization’.  Nordion’s Richard Wiens, Director of Business Development & Strategic Supply, discussed the global supply chain and efforts to expand Cobalt-60 production.

The webinar opened with an introduction to the features, benefits, applications and advantages of gamma irradiation and gamma irradiators.  80-85% of the capacity of the ~300 large scale gamma irradiators globally is used for the sterilisation of single use medical devices.  Gamma sterilisation amounts to about 30% of single use devices globally.  In the U.S. approximately 40% of single use devices are sterilised using gamma irradiation, equivalent to ~16B devices annually.

The Cobalt-60 production process was described, starting with high-purity Cobalt-59 sintered into nickel plated slugs that are placed into adjusters that are inserted into reactors for 18-60 months for conversion to Cobalt-60.  The irradiated adjusters are shipped to Nordion where they are disassembled to recover the slugs that are then used to produce the finished sealed sources

The supply chain was discussed with an introduction to some of the supply and demand dynamics.  Historically the demand for Cobalt-60 grew at a rate of 2-3% p.a. until 2018 but has since doubled to 5-6%. Whilst Cobalt-60 supply continues to grow, it now lags demand.  Reference was made to 2026 being the timeframe when production volumes will start to fall back in line with higher growth rates and demand.

Cobalt-60 production is currently limited to 19 CANDU and RBMK type reactors globally.  In order to increase production capacity, Nordion is partnering with Westinghouse and they are working towards starting production in Pressure Water Reactors (PWR’s), a different and more common reactor platform, particularly in the USA.  65% of reactors worldwide are PWRs, with 64 located in the U.S. This represents a good opportunity for expansion of Cobalt-60 production.

Projects are also ongoing to increase production with existing suppliers and reactor types.  4 CANDU reactors operated by OPG in Darlington are being converted to enable Cobalt-60 production and the first additional cobalt from these reactors will be in ~2028.  Additional Cobalt-59 adjusters are also being installed at Bruce Power reactors. These are expected to contribute to additional Cobalt-60 supply in ~2026.

Other opportunities to maintain Cobalt-60 supply include the potential refurbishment of the OPG reactors in Pickering that were scheduled to close in 2024/25.  This refurbishment, that is being studied to help meet increased electricity demand, would extend the working life of the reactors and Cobalt-60 production for a further 25 years.  Other initiatives, such as collaboration with Cobalt-60 producers in India and Argentina, were also discussed.

Several other topics including the Cobalt-60 usage efficiency, recycling, irradiator design and sustainability were also discussed.  The webinar concluded by summarising that: gamma irradiation is “alive and thriving’. Gamma will remain an important part of global sterilisation supply for the foreseeable future. Gamma remains an important technology due to its simplicity and reliability; existing supply of Cobalt-60 supports current demand for replenishment with some growth with additional growth available after 2026; ongoing investment of >USD150M in new supply coupled with efficiency improvements will ensure reliable availability of gamma capacity. Recent indecent studies are concluding that gamma irradiation is the most environmentally sustainable choice for sterilisation due to low energy use and recycling of 99% of material returned from the market.

A recording of the webinar will be made available via the Sotera Health Academy shortly.

For further information about the critical production of Cobalt-60 in nuclear reactors, please read this iia article from March 2023 published in World Nuclear News:


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