Highly enriched uranium in Canada

Highly enriched uranium (HEU) is produced in the U.S. and is used in Canada as a source fuel in a number of nuclear research reactors. HEU is also used to produce life-saving medical isotopes at Canadian Nuclear Laboratories Ltd.’s (CNL) Chalk River Laboratories (CRL). CRL is one of the world's largest suppliers of medical isotopes, which are used in the diagnosis and treatment of diseases. To date, millions of critical procedures using medical isotopes have been performed in Canada for cardiac diagnosis, cancer investigation and cancer treatment.

Since the 1990s, Canada has joined global non-proliferation efforts and converted several of its research reactors to low-enriched uranium. Canada has more recently furthered this commitment by agreeing to send back used HEU to the U.S. to help consolidate HEU inventories in fewer locations.

Background on HEU repatriation

The Prime Minister announces an agreement with the United States to repatriate inventories of highly enriched uranium (march 2012).

The Prime Minister announces an agreement with the United States to repatriate inventories of highly enriched uranium (march 2012).

In April 2010, Canadian Prime Minister Harper and United States President Obama committed to returning spent HEU fuel to the U.S. as part of a broad international effort to consolidate HEU inventories in fewer locations around the world. The commitment promotes non-proliferation by removing existing weapons-grade material from Canada and eliminates a nuclear liability for future generations of Canadians. Once the material is returned to the U.S., it will be reprocessed and used in American nuclear power plants to produce energy.

As a result of this agreement, regular shipments of used HEU fuel from CRL and other reactors are currently being transported safely back to the U.S.

Following the 2010 agreement, Prime Minister Harper committed, in March 2012, to repatriate additional Canadian HEU inventories, including those in liquid form from (known as Highly Enriched Uranyl Nitrate Liquid, or HEUNL) past production of medical isotopes.

CNL is currently assessing options to fulfill Canada's commitment and return these liquid HEU inventories to the U.S. Shipments would follow the same stringent transportation and security requirements as the transport of HEU fuel bundles.

FISST storage

A new electro-optical seal related to the monitoring system on the fissile solution storage tank was installed in 2011, as part of the safeguards agreement between Canada and the IAEA.

A new electro-optical seal related to the monitoring system on the fissile solution storage tank was installed in 2011, as part of the safeguards agreement between Canada and the IAEA.

Until 2003, liquid inventories containing HEU were stored in a double-walled stainless-steel vessel known as the Fissile Solution Storage Tank (FISST), located at CRL.

Since 2003, when FISST reached its storage capacity, new liquid material generated from medical isotope production has been cemented and is in long-term storage at CRL.

The FISST vessel (now full) is inside a vault shielded by thick concrete. It is monitored for temperature, pressure, and chemical composition. Its content is sampled once a month for detailed chemical analysis. These activities ensure that the vessel's contents are stable and remain safe at all times. During the mandatory sampling procedures, information is recorded electronically and sent to the CNSC and the International Atomic Energy Agency (IAEA).

Since the FISST contains HEU, the facility is under high-level security and is under close regulatory oversight by the CNSC and the IAEA at all times. In 2011, the IAEA, in collaboration with the CNSC and CRL, installed an upgraded monitoring system, to continue to ensure the proper inventory control of the contents of the tank.

The safety of the FISST was discussed at a CNSC two-day public hearing in 2011 for the re-licensing of CRL.

Certification of transport package design for HEUNL

The package design for the transport of HEUNL requires certification by both US and Canadian authorities before it can be used.

In order to be certified in Canada, the package design has to undergo stringent testing, which simulates both normal and hypothetical conditions of transport, including free-drop testing, puncture testing and thermal testing.

The package design must comply with the CNSC Packaging and Transport of Nuclear Substances (PTNS) Regulations. These regulations, based on the International Atomic Energy Agency (IAEA) Regulations for the Safe Transport of Radioactive Material, establish strict standards of safety which provide an internationally acceptable level of control of the radiation, nuclear criticality and thermal hazards to persons, property and the environment that are associated with the transport of radioactive material.

Persons must also register the use of the package with the CNSC and acknowledge that the necessary training to properly prepare it for shipment is in place. The CNSC will only certify the package when it is certain that it satisfies all regulatory requirements.

Public consultation on HEUNL transport package design

In 2014, the CNSC received an application for package design certification and assessed it to ensure that it satisfied all regulatory requirements. The Technical Assessment Report on the NAC-LWT Package Design for Transport of Highly Enriched Uranyl Nitrate Liquid (HEUNL) was available for written public comment from December 23, 2014 to February 9, 2015. The report included an environmental assessment (EA) performed under the Nuclear Safety and Control Act (NSCA)

On July 10, 2015, the CNSC issued a certification for the NAC-LWT package design for the transport of HEUNL.

Document Milestone Dates Links
Consultation December 23, 2014 to February 9, 2015 View News Release
View the Technical Assessment Report on the NAC-LWT Package Design for Transport of Highly Enriched Uranyl Nitrate Liquid
Invitation to provide feedback on comments received May 4, 2015 to June 4, 2015 View the comments received
Feedback received June 10, 2015
Decision for Canadian certification July 10, 2015 View News Release
View the Record of Decision (PDF)
View the Certificate – Endorsement of Transport Package Design by the CNSC (PDF)
View the Consultation Report (PDF)

The CNSC Staff Recommendation and the Disposition Table are available on request. Please contact INFO.

Licensing of HEUNL transportation

Once the transport package has been certified for use, an application must be made to the CNSC for a transport licence. Each shipment of HEUNL requires its own individual transport licence, and is only valid for a specific number of days.

The application for a CNSC transport licence must include a transport security plan that requires:

  • a full description of the nuclear material
  • a threat assessment to identify any credible threats
  • a description of the type of vehicle used to transport
  • the proposed security measures in place during transport, such as continuous tracking and type of escort
  • the communications arrangement between the carrier and the response force (ex: Canadian police agencies)
  • the communication arrangement between the licensee and the response force
  • the primary and alternate transportation routes

Under Transport Canada's Transportation of Dangerous Goods Regulations, any shipment of fissile material (such as HEUNL) requires an emergency response assistance plan that must be approved by Transport Canada. The Transport Canada regulations also require the consignor to display a 24-hour emergency telephone number on all shipping documents that accompany each shipment to ensure that appropriate technical assistance is immediately available to emergency first responders.

The CNSC will issue the transport licence only when it is certain that the shipment satisfies all regulatory requirements.

The CNSC also requires that an export licence be issued for these shipments. The licence ensures that the material conforms to Canada's nuclear non-proliferation policy, international obligations and commitments, and regulatory requirements, and that the material being transferred is used in only peaceful applications.

Status of HEUNL shipments

The following represent various milestones involved in the shipment of liquid HEU.
Milestone Status
United States Department of Energy (USDEO) Supplement Analysis
USNRC certification of transport package design
US Department of Transport certification of transport package design
CNSC certification of transport package design
Application for transport licence
  • Application received and assessed, licence issued.
    • prescribed information
Application for export licence
  • Application received and assessed, licence issued
    • prescribed information

Transportation of radioactive substances in liquid form

Canada is one of the world’s major producers of nuclear substances (radioactive material) and has an excellent safety record for transporting radioactive material.

More than a million packages containing radioactive material are transported safely in Canada each year.

The CNSC and Transport Canada share the responsibility for ensuring safe transport of nuclear substances.

Some of the radioactive substances transported are in liquid form. For instance, many of the medical isotopes and heavy water used in CANDU reactors containing tritium are commonly transported.

Canada also has vast experience in transporting large quantities of solid radioactive materials. For instance, Canada is a major producer of cobalt-60 sources, which are used in radiation therapy and several industrial applications such as irradiation (for example, to destroy potentially harmful bacteria in food or on medical equipment).

Small quantities of used fuel bundles are also regularly sent by nuclear power plant operators to CRL for examination purposes.

CNSC inspectors perform regular inspections to verify that licensees and carriers are complying with regulations.

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