McMaster University staff submitted an application for a Class IB Processing Facility licence to the Canadian Nuclear Safety Commission (CNSC) on June 30, 2026, for the Centre for Advanced Nuclear Systems (CANS) hot cell facility. The CANS facility is a suite of hot cells and specialized equipment on the McMaster University campus used to enable leading edge nuclear materials research. The CANS facility has been used in an important role in the global medical isotope supply chain, including the processing of Lutetium-177 used in over 100,000 patient treatments annually. The Class 1B Licence will enable continued support of research and innovation in the health and energy sectors.

An employee at the McMaster Nuclear Reactor was injured on March 26, 2026, while performing routine material movements using an industrial crane. The employee was taken to hospital for assessment and treatment and was released later that evening. The employee has been medically cleared to return to work and started their return on May 12, 2026.

There was no radiological exposure or loss of contamination control as a result of the event.

As required, the incident was reported to the Canadian Nuclear Safety Commission. McMaster is conducting an investigation to understand the contributing factors and identify any corrective actions needed to help prevent a similar incident in the future.

Read Report (2025)

Read the article here. 

Technical experts from the CNSC will be conducting a Type II General Inspection at the McMaster Nuclear Reactor from February 3-5, 2026, with a focus on the following safety and control areas:  Waste Management, Radiation Protection, Emergency Management and Fire Protection, Fitness for Service, and Operating Performance. CNSC staff will summarize any findings in a formal report provided to the University.

IAEA safeguards inspectors will be visiting the McMaster Nuclear Reactor on January 30, 2026, to carry out a design information verification (DIV) inspection. This is to ensure proper application of safeguards per the agreement between Canada and the IAEA with respect to the Treaty on the Non-Proliferation of Nuclear Weapons (INFCIRC/164).

Read report (2024).

On March 29, 2025 NOF submitted an application to the CNSC for to consolidate the operating and servicing licences for the McMaster University Cyclotron Facility into a single license.

Environment and Climate Change Canada recently announced funding to McMaster University, part of which is intended for the capture and use of waste heat from the McMaster Nuclear Reactor (MNR) to reduce carbon emissions. Canadian Nuclear Safety Commission staff have been informed of McMaster University’s intent to pursue this project. MNR staff are engaged with this project and are proud to support the initiative. No changes to the MNR facility or operating licence will be made without first obtaining required regulatory approvals.

McMaster University has reported the incident to the Canadian Nuclear Safety Commission (CNSC) and is working with local staff in Tennessee to coordinate repackaging of the shipment.

McMaster University will test its response to an on-campus radiological incident during a planned exercise on Wednesday, Oct. 9, beginning at 8:30 a.m. Emergency response vehicles and personnel will be on campus from about 7 a.m., but this is a test and will have no impact on the community. The exercise, in collaboration with city emergency services, will involve an accident scenario in the McMaster Nuclear Reactor (MNR). Setup for the exercise will start around 7 a.m., when emergency response vehicles and personnel may be seen on campus. The exercise will run from 8:30 a.m. until 1:30 p.m. Fencing will be set up around the Nuclear Research Building and the reactor, and access to this area will be very limited.

Read full article.

Technical experts will conduct an inspection of Fire Protection and Emergency Preparedness at the McMaster Nuclear Reactor from October 4 to 11, 2024. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University.

Technical experts from the CNSC conducted a Type I inspection at the McMaster University Cyclotron Facility on April 24^th to 26^th 2024.  The CNSC noted areas for improvement, and subsequently requests for license amendments were submitted on July 9^th 2024.

Technical experts from the CNSC conducted a virtual inspection of Safety Analysis and Operating Performance at the McMaster Nuclear Reactor from May 7 to 9, 2024. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University.

Read report (2023).

Inspectors from the International Atomic Energy Agency accompanied by Canadian Nuclear Safety Commission staff were provided access to the MNR on November 16, 2023 to carry out physical inventory verification and design information verification. Visual observations and radiological measurements were performed by the inspectors to verify MNR’s compliance with international safeguards agreements.

Technical experts from the CNSC conducted a Type II General Inspection of various safety and control areas at the McMaster Nuclear Reactor held between November 15 and 21, 2023. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University in the next few weeks.

• The drill is scheduled to take place between 09:00 and 13:00 on November 16^th
• A large area of the South-West parking lot at 44 Frid St. will be required to support the drill and an exclusion zone will be set-up around this area (see diagram below)
• The drill will include a simulated transportation accident involving a radioactive shipment from McMaster University on a public road.  No real radioactive material will be used as part of this drill.
• The drill will include vehicles that look like they have been in an accident and radiological packages that look like they have been damaged.

Read full article.

Read article.

Read report (2023).

In May 2023, McMaster University staff removed International Atomic Energy Agency (IAEA) safeguards seals from a shipment in error without prior CNSC approval, a violation of the General Nuclear Safety and Control Regulations (GNSCR). The shipment was part of an agreement between McMaster University and the decommissioned Greek Research Reactor in Athens to receive unused nuclear material from the site, – diverting it from planned disposal for use at the McMaster Nuclear Reactor to support nuclear research, innovation and medical isotope production.

 A miscommunication during the shipping process led McMaster staff to understand they were approved to remove the seals on the shipment, although it was later identified this was not the case. Nuclear materials are regularly received at the McMaster Nuclear Reactor and handled in a safe and fully compliant manner. However, this is the first occasion that material arrived under IAEA seals.

McMaster staff reported the receipt of the shipment to the Safeguards Division of the Canadian Nuclear Safety Commission (CNSC) within 24 hours as required, and the IAEA was informed. Soon after, an IAEA inspector performed a 100% inspection and confirmed that all nuclear material shipped from Athens was in secure, safe storage at McMaster University. McMaster staff worked with the CNSC to develop a corrective and preventive action plan to prevent any recurrence of this situation. There were no consequences to the safety of the public or the environment as a result of this event.

Read notice.

On April 19, 2023 NOF submitted an application to the CNSC for a renewal of the MNR Non power reactor operating licence for a twenty year licence period. The current licence expires on June 30, 2024.

Read report (2022).

Inspectors from the International Atomic Energy Agency accompanied by Canadian Nuclear Safety Commission staff were provided access to the McMaster Nuclear Reactor on April 6, 2023 to perform a visual inspection as part of a Complementary Access request from the agency. 

Technical experts from the CNSC conducted a Type II Inspection of the Radiation Safety Program at the McMaster Nuclear Reactor on September 21, 2022. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University in the next few weeks.

Read report (2021).

On November 15, 2021, McMaster University was informed by a customer in Europe that one of their packages containing the medical isotope I-125 for patient treatment was found to have higher than normal radiological readings.

Prior to leaving the McMaster Nuclear Reactor, medical isotopes are securely and safely packaged within multiple layers of containment; the final one being a shipping box.  Packages are closely monitored and inspected before they leave the facility.  In this case, none of the packaging was found damaged and there was no release of material out of the package, however, the higher fields detected by the customer need to be investigated and MNR is working with their customer to determine the cause.

There were no radiological consequences to the public or environment, as a result of this event.

McMaster University has reported the incident to the Canadian Nuclear Safety Commission (CNSC) and is following up on this non conformance.

McMaster University tested its response to an on-campus fire incident during a virtual exercise on Friday, June 18 beginning at 10:00AM.

The exercise, in collaboration with the city’s emergency services, involved a tabletop fire scenario in the McMaster Nuclear Reactor.

While there were emergency response vehicles and personnel on campus, this was a test and had no impact to the community.

Read report (2020).

The CNSC conducted a Management System inspection at the facility on March 2-3, 2021. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University in the next few weeks.

On March 16, 2021, McMaster University was informed that the outer container of a package containing the medical isotope, I-125 for patient treatment, was found damaged at a Toronto airport warehouse, while in transit to a customer in China.

Prior to leaving the McMaster Nuclear Reactor, medical isotopes are securely and safely packaged within multiple layers of containment; the final one being a shipping box.  Packages are closely monitored and inspected before they leave the facility.  In this case, it was the final layer of the shipping box which was noted to be damaged.  McMaster staff evaluated pictures of the package and determined that there was likely no safety impact associated with the incident.  The package was returned to McMaster where the package was assessed and confirmed to have only minor exterior damage.

There were no radiological consequences to the public or environment, as a result of this event.

McMaster University has reported the incident to the Canadian Nuclear Safety Commission (CNSC) and has repackaged the medical isotope for shipment to the customer in China.

Read report (2019).

On April 19, 2020, McMaster University was informed that the outer container of a package containing the medical isotope, I-125 for patient treatment, was found damaged after arriving in Montreal, Quebec from Toronto Pearson airport.

Prior to leaving the McMaster Nuclear Reactor, medical isotopes are securely and safely packaged within multiple layers of containment; the final one being a shipping box. Packages are closely monitored and inspected before they leave the facility. In this case, it was the final layer of the shipping box which was noted to be damaged. McMaster staff evaluated the package and determined that there was no safety impact associated with the incident. The package will be repacked and sent to the medical facility at its destination in China.

There were no radiological consequences to the public or environment, as a result of this event.

McMaster University has reported the incident to the Canadian Nuclear Safety Commission (CNSC) and is working with local staff in Quebec to coordinate repackaging of the shipment.

Please see below for McMaster Nuclear Operations and Facilities response to COVID-19.

Nuclear Operations COVID-19 Response Memo, 18th March.

The CNSC conducted a Human Performance Management inspection at the facility on March 9-10, 2020. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University in the next few weeks.

Security experts from the CNSC conducted a Security inspection at the facility on October 22, 2019. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University in the next few weeks.

McMaster University will test its response to an on-campus radiological incident during an exercise on Wednesday, September 25 beginning at 9:30 a.m.

The exercise, in collaboration with the city’s emergency services, will involve an accident scenario in the McMaster Nuclear Reactor.

While there will be emergency response vehicles and personnel on campus, this is a test and will have no impact to the community.

More details.

Read report (2018).

On January 22nd, 2019, a package containing Lu-177 was shipped from the MUCF and was delivered to the wrong hospital. Fortunately, the receiving hospital was equipped and staffed to handle the delivery. Subsequently, they reshipped the isotope to its intended destination.

On January 6th, 2019, a courier vehicle transporting F-18 produced at the MUCF had a tire blow out. The blowout caused the vehicle to hit a guardrail which resulted in minor damage to the vehicle. However, the F-18 package was undamaged. Another vehicle was dispatched and the shipment has since been received by the consignee without further incident.

Technical experts from the CNSC conducted a Type II inspection at the facility on November 14/15, 2018. The CNSC will summarize the results of the inspection in a formal report and will provide it to the University in the next few weeks.

McMaster University has applied to the CNSC for a license to use, ship and store the radio isotope Zirconium 89. Zr-89 is a short lived positron emitting isotope used for the diagnosis and treatment of various illnesses.

On Tuesday July 31, 2018, McMaster University was informed that the outer container of a package containing medical isotopes used to treat prostate cancer was found to be damaged upon arrival at the Lufthansa warehouse at Pearson Airport in Toronto, ON. The medical isotope was securely and safely packaged within 5 separate layers of containment; the final one being the shipping box which was noted to be damaged.

McMaster staff responded to the warehouse, inspected and performed radiological surveys of the package.  We determined that there was no safety impact associated with the incident. The package was repackaged and is currently in transit to the customer.

There was no release of radiation from this shipment and no threat to the public, environment or safety as a result of this incident.

On July 15, 2018, McMaster University was informed that the outer container of a package containing the medical isotope, Lu-177 for medical use, was found damaged upon arrival at the airport in Australia.

Prior to leaving the MUCF, medical isotopes are securely and safely packaged within multiple layers of containment; the final one being a shipping box.  Packages are closely monitored and inspected before they leave the facility.  In this case, it was this final layer of shipping box which was noted to be damaged.  Australian authorities inspected the package and determined that there was no safety impact associated with the incident.  The package was repacked and sent to the medical facility later that day.

There were no radiological consequences to the public or environment, as a result of this event.  No activity was released from the package. McMaster University has reported the incident to the Canadian Nuclear Safety Commission (CNSC) and is working with the transportation company to investigate the cause of the damage.

During normal operations this morning (May 25 2018) a quantity of F-18 failed to deliver to its intended hot cell and was trapped in the delivery line.  This resulted in elevated radiation fields in a small area adjacent to the eastern doors to the facility.  As a precaution the affected area was marked off with chains and bollards to ensure no member of the public was exposed to the elevated fields.   At no time were fields of sufficient magnitude to present a hazard to the general public.

Read report (2017).

On February 08, 2018, two packages of F-18 for medical use were delivered to the air carrier, one destined for Thunder Bay and one destined for Ottawa. Both packages had their flights
rescheduled by the carrier. The two shipments were then both delivered to Ottawa one on the 8th of February and the second on the 9th.

An investigation is ongoing.

Technical Experts from the CNSC conducted a Type II Inspection at the facility on November 23, 2017. The CNSC will summarize the results of the Inspection in a formal report and provide it to the University in the next few weeks.

IAEA Inspectors attended MNR on November 3, 2017 to perform a facility inspection.

The IAEA will summarize the results of the Inspection in a formal report and provide it to the University in due course.

The CNSC has renewed the McMaster University Cyclotron Facility (MUCF) service license for a 5 year period, expiring May 31, 2022. There were no substantial changes to the MUCF sections of the service license.

Read report (2016).

On February 28, 2017, the McMaster University Cyclotron Facility (MUCF) received an amendment to its license to operate requiring that it maintain a Public Information Disclosure Program (PIDP). Going forward this site will contain any announcements or news releases that are required under the MUCF PIDP policy.

Technical Experts from the CNSC conducted a Type II Inspection at the facility on July 28th, 2016.

The CNSC will summarize the results of the Inspection in a formal report and provide it to the University in the next few weeks.

A fire occurred yesterday afternoon at the University in a building which is located adjacent to the Research Reactor. The Hamilton Fire Department responded and the fire was quickly extinguished, with no injuries reported. While the fire had no impact on the reactor, it was temporarily shut down as a precautionary measure. Normal operations have resumed on Friday July 8, 2016. There were no safety impacts to the reactor as a result of this situation.

Read report.

On Wednesday, August 06 2015, McMaster University was informed that a shipment containing medical isotopes had been “lost” by the courier. Medical isotopes are used in the treatment of cancer and are routinely produced at research reactors. The package in question was tracked to a large distribution center in the US operated by the shipping company where it had become lost.

McMaster University has reported the incident to the CNSC and is working with the courier to help locate the package.

On Tuesday August 04, 2015, McMaster University was informed that the outer container of a package containing medical isotopes used to treat prostate cancer was found damaged upon arrival at the airport in France. The medical isotope is securely and safely packaged within 5 separate layers of containment; the final one being the shipping box which was noted to be damaged. French authorities inspected the package and determined that there was no safety impact associated with the incident. The package was placed in an over pack and delivered to the medical device manufacturer later that day. There were no radiological consequences. No activity escaped from the package. Only the cardboard shipping box was damaged. McMaster University has reported the incident to the CNSC and is investigating the cause of the damage.

Update: Oct. 10/14 3:30 pm

The Canadian Nuclear Safety Commission has granted its approval for the research reactor to be restarted. The reactor will resume operations on Tues. October 14.

Oct. 10/14 – 11:30 am

McMaster is finalizing its plan to restart its research reactor after temporarily shutting it down Wednesday, Oct. 8th.

An error during a routine refueling prompted an unscheduled shut down.  There were no impacts to the public or the environment, no injuries to workers, and no observed damage to the fuel assembly.  The Canadian Nuclear Safety Commission has been notified and has been in communication with the University on its plan to restart the reactor.

A preliminary review has determined that an error occurred during a routine operation involving the fuel assemblies.  The assemblies are submerged under 27 feet of water within the reactor but one was not in a position connected to the reactor’s cooling system during the re-start.

The operator realized the error and immediately shut down the reactor and reported the incident.  No radiation or fission products were released. The reactor was then restarted and operated normally before being shut down for the day as scheduled. Upon further review, the University determined that approval from the CNSC is required for a restart. McMaster will proceed with restarting the reactor once that approval is granted. An application is expected to be submitted to the CNSC today.

Shutting down the reactor and restarting it are daily occurrences. During normal operations, the reactor is shut down every night and restarted each morning.

An internal investigation has begun to determine how the error occurred and to identify steps to ensure similar errors are prevented from happening again. The McMaster  reactor is a teaching and research facility. It does not generate electrical power and in addition to its research mandate is used to produce medical isotopes for the treatment of cancer and other illnesses.