Need for UK to secure a sustainable supply of future medical radioisotopes

  • 9 December 2020
  • General
  • Dr Robert Hoyle

Back in 2009, a global shortage of Molybdenum-99 was caused by a temporary suspension from the world’s major supply nuclear reactors, in particular Petten in the Netherlands. This resulted in significant widespread delays and disruptions to medical services involved in the diagnosis of many diseases, particularly cancers and implications for the long-term survivability of patients.

Molybdenum-99 is the ‘parent’ isotope of Technetium-99m - the active component used in diagnostic SPECT gamma scans (Single Photon Emission Computer Tomography). The supply shortage of Molybdenum-99 – due to a technical fault in one of the production facilities exposed the fragility of the world’s supply chain for medical radioisotopes. Currently, the global supply of Molybdenum-99/Technetium-99m continues to be dependent on a small number of aging nuclear reactors built in the 1960s (see Figure 1 below). 

Vulnerability of world and UK supply of medical isotopes

Over the past decade, many of these early reactors have closed and or have been decommissioned. Only a handful are left to supply a growing market demand for diagnostic and therapeutic medical radioisotopes, and other industrial and research purposes. The plan by countries with nuclear capacity to move away from using high enriched uranium test reactor fuel, which causes proliferation concerns, has also meant that many other small research reactors have also had to close.

Reactor Country Share of Global Capacity Reactor First Criticality  Reactor Planed Shutdown


Russian Federation 5%

RBT-6 –1975
RBT-10 –1983

HFR Netherlands 26% 1961 2026
BR2 Belgium  15% 1961 2026
RA3 Argentina 2% 1967 2027
LVR-15 Czech Republic  10% 1957 2028
MARIA Poland  9% 1974 2030
SAFARI-1 South Africa 14% 1965 2030
MURR USA 4% 1966 2037
FRM-II Germany 12.7% 2004 2054
OPAL Australia 6% 2006 2057
PALLAS Netherlands Replacement for HFR. Project launch in 2007 but funding was cut in 2009. Re-started in 2015, currently expected online in 2025 but construction has not yet started bringing uncertainty to the project.
MYRRHA Belgium Replacement for BR-2, primary focus on material testing. Experimental liquid cooled, accelerator driven reactor but it is not expected to be online until 2035 at the very earliest.

Figure 1: Isotope production reactors, their location, percentage of world supply and their expected shutdown dates.

There have been other temporary world shortages since 2008/2009, including recently in October 2018 where the University of Iowa raised concerns:  

 Worldwide shortage of radioisotope Tc99m to impact Nuclear Medicine service: “The Division of Nuclear Medicine in the Department of Radiology is experiencing a shortage of the radionuclide Tc99m (technetium 99), which is commonly used to image the body in nuclear medicine scans. A worldwide shortage of the radioisotope will impact a majority of diagnostic scans done in the Nuclear Medicine clinic for approximately two weeks, from Nov. 5 through 19”.

The British Institute of Radiology had previously noted that “over the last few years there have been a number of supply shortages of the most widely used medical radioisotope, molybdenum-99 (99Mo), and its decay product, technetium-99m (99mTc)”. 

Recognising the fragility of the world supply the OECD Nuclear Energy Agency (NEA) stated: “During the 2009-2010 period, there were substantial shortages, at times up to 70% of world demand of the most widely used medical radioisotope, molybdenum-99 (99Mo), and its decay product, technetium-99m (99mTc)”.

The most widely used medical radioisotopes in the UK and world-wide is the Molybdenum-99/Technetium-99m parent/daughter combination produced in high-flux non-power nuclear reactors. This accounts for approximately 80% to 85% of all medical isotope use. Scanning techniques such as Positron Emission Tomography (PET) use other isotopes such a Fluorine-18 (F18) produced by a different technology and accounts for a much small number of diagnostic scans. In addition, most therapeutic uses of radioisotopes, for example iodine-131 for treating hyperthyroidism and thyroid cancer, are produced in small nuclear reactors along with the molybdenum-99/technetium-99m.

UK’s cancer treatment performance

Early diagnosis and treatments from nuclear medicine remains a major contributing factor to increasing survivability rates. Unfortunately, the UK has a poor record of treating cancers compared to other leading industrialised countries. Recognising that action was needed, NHS England commissioned Sir Mike Richards to undertake a review of cancer screening services in 2019. At the launch of the review, Professor Richards noted:

Screening is vital for the NHS to catch cancers earlier and save even more lives”. Early diagnosis of cancers is essential for successful treatment and SPECT using technetium-99m is a major diagnostic tool for detecting the extent and spread of cancers. Unfortunately, the UK is not well provisioned with SPECT and other diagnostic services compared with many other leading countries and this is compounded further by unreliability of radioisotopes supply, as illustrated in Figure 2.

Figure 2: Relative number of gamma camera diagnostic scans (SPECT) undertaken per thousand population by country. (Source: The Supply of Medical Isotopes, AN ECONOMIC DIAGNOSIS AND POSSIBLE SOLUTIONS 2019, OECD & NEA Nuclear Energy Agency)

Recently the UK Government’s NHS Long Term Plan, has committed to diagnosing three-quarters of cancers at an early stage by 2028 delivered through improved screening processes. By 2028 the Plan commits to dramatically improve cancer survival, from a half to three quarters. To support this, as part of the recent Spending Review, the UK Government has committed £200 million of new funding towards addressing this issue.

UK’s future vulnerability for supplying medical isotopes  

Currently, the UK has small nuclear reactor capable of producing radioisotopes. Apart from PET radioisotopes it relies almost entirely on the import of molybdenum-99 and other medical radioisotopes from overseas, mainly from Europe. Given the experience over several years and the lack of an indigenous supply, the UK continues to vulnerable not only to global shortages, but to interruptions in transporting and importation of the products.

A report produced for Government by NIRO (Nuclear Research and Innovation Office) in 2019 shows that the supply situation for medical radioisotopes is expected to become more fragile in the future, producing more severe shortages as the existing research reactors are closed down in Europe and elsewhere, unless new reactors are built. 

A significant proportion of world supply is expected to be lost by about 2030 as between 3 and 4 of the remaining reactors are due to close due to their age. So far and despite much discussion no new reactors have started construction in Europe and very few elsewhere in the world. Promises of accelerator-based production facilities have not materialised and have not been taken forward at the scale required to service future growing need. 

Financing new reactors is problematic because the accepted ‘market’ prices for bulk molybdenum-99 and other isotopes do not cover the capital investment and running costs. Unless governments are prepared to provide the leadership and a major proportion of the construction cost, new or replacement reactors are unlikely to be built. As with other nuclear endeavours, the private sector has proved unwilling to fund new reactors of any type, either power reactors or research reactors.

Wales and nuclear power generation 

Wales has a long history of nuclear power generation, having had two operational Magnox power stations at Wylfa (Anglesey) and Trawsfynydd (Gwynedd). Wylfa was commissioned in 1971 but closed in 2015 while Trawsfynydd was commissioned in 1965 and closed in 1991. Families in North West Wales have had two or even three generations who have worked or are working still in either facility as they are decommissioned. Consequently, there is a high level of acceptance of nuclear power generation within local communities and such acceptance is found in only a few other places in the UK.

Nuclear has been a major employer in North Wales, providing high value, long lasting employment for many people in what is otherwise one of the poorest areas of the UK. Recently, Trawsfynydd was identified as the best site by the Rolls Royce report for the establishment of a new Medical Radioisotopes and Research Reactor (MRRR). Trawsfynydd is attractive for new nuclear because it is publicly owned through the Nuclear Decommissioning Authority whereas most of the other Magnox sites have been earmarked for, and are surrounded by land owned by potential large scale nuclear developers, though only one, Hinkley Point C, is under construction. 

As part of the Snowdonia Enterprise Zone strategy, the Welsh Government has established and funded a Trawsfynydd Site Development Programme. This has the remit to develop the site to create job opportunities and economic growth at the former nuclear power station site in the rural and geographically peripheral economy of southern Gwynedd. This Programme aims to deliver projects that create high value, long-term employment. While the project portfolio may evolve over time, current projects include: Small Modular Reactors (SMRs); Medical Radioisotopes and Research Reactor (MRRR) and Spherical Tokamak for Energy Production (STEP).

Developing a National Thermal Hydraulic Facility has been another project for Welsh Government designed to deliver part of UK Government BEIS’ nuclear innovation programme and Nuclear Sector Deal. The ability to undertake physical research and testing to validate thermal hydraulic computer models is an essential component in the design and development of new reactor technologies. In collaboration with BEIS, the Welsh Government has already committed up to £20 million for this £40 million project, which will complement a £6 million Welsh Government Sêr Cymru investment in the Nuclear Futures Institute research group at Bangor University.

Medical Isotopes

Faced with the poor socioeconomic situation in North Wales and recognising that the best way to address future shortages in medical radioisotopes is to develop an indigenous UK supply chain, the Welsh Government commissioned an independent radioisotopes ‘options study’. This investigated the opportunity for creating a world-class centre for medical radioisotopes production surrounded by extensive radio-medicines, radiotherapies and diagnostics research and treatment facilities in North Wales capable of serving the UK need.

The Rolls Royce report concluded that the most mature reactor technology would be based on the Australian Nuclear Science and Technology Organisation’s Open Pool Australian Light water reactor facility (ANSTO OPAL). All existing UK nuclear licensed sites were considered and the optimal site was found to be Trawsfynydd because of its existing infrastructure, skilled workforce, excellent facilities, socioeconomic impact and location. The cost for a facility similar to that of ANSTO would be in the region of £400 million and could be built within a timescale which would secure a supply of medical radioisotopes for the UK – at a time when the world supply shortages are expected to become particularly vulnerable and acute (i.e. 2028 to 2030).

A research reactor generating isotopes costs money to build but thereafter, because there is a growing world market in medical isotopes, the future operating costs of the reactor and the production of isotopes for both diagnosing and treating cancers could be covered by sales of the isotopes into the global market, benefiting the UK and humanity more generally.

The Welsh Government Office for Science has been working collaboratively with colleagues in BEIS, MOD Nuclear and other stakeholders for some time to build the case for the next stage. Building on previous work this will involve undertaking a feasibility study and options for a dedicated research facility with a view to ensuring that the UK has an indigenous, secure and sustainable supply of medical radioisotopes that help save lives throughout the UK.

Dr Robert Hoyle, Head of Science within the Welsh Government Office for Science, Welsh Government.

Robert’s role involves supporting the Chief Scientific Advisor for Wales (CSAW) on many aspects of science advice and policy for the Welsh Government. Currently, much of this work is COVID-19 related but science advice has been sought on many different and often difficult political issues, from fracking and shale gas, e-cigarettes and nicotine to badgers and bovine TB.

As a result of the recent challenge of diagnosing and treating patients due to COVID-19 and the threat to reliable supplies of medical radioisotopes due to Brexit, the Welsh Government Office for Science has been exploring the short, medium and long term supply situation. This has revealed the threat to the long term world supply of medical radioisotopes, the mitigation of which will require replacement reactors or the development of other technologies all of which fall within the remit of ‘science’. Robert is leading on this issue along with other nuclear related projects such as establishing a UK national nuclear thermal hydraulics facility. Prior to joining the Welsh Government, Robert worked in private sector industry in South Wales.