National Sealed Source Registry and Sealed Source Tracking System Report for 2017
Sealed sources are radioactive nuclear substances encased in a sealed capsule or in a cover to which the substance is bonded. They can be used for a variety of activities, including medical, industrial, commercial, and academic and research applications. An inventory of sealed sources within Canada is housed in the National Sealed Source Registry (NSSR), which was established in 2006 to conform to the International Atomic Energy Agency (IAEA) Code of Conduct on the Safety and Security of Radioactive Sources. The NSSR is used to maintain an accurate and secure inventory of sealed sources in Canada, with a particular focus on those classified as high risk.
The Sealed Source Tracking System (SSTS) is a secure information-management system used in conjunction with the NSSR to track new and existing high-risk sources within Canada. Source transfers done online through the SSTS update and populate the NSSR so that the information is as current as the licence reporting allows (e.g., reporting within two days of receipt and seven days in advance of any transfer). The CNSC places particular emphasis on capturing data on high risk sources, with the NSSR housing detailed information such as the serial number, isotope, activity, and current location. Information on moderate- and low-risk sources is updated annually using the inventory data included in licensee's annual compliance reports (ACRs) and validated by the CNSC for accuracy and consistency.
Categories of sealed sources
Sealed sources are classified by the IAEA into five different categories:
Category 1
Very high risk
(risk-significant)
Category 2
High risk
(or risk-significant)
Category 3
Moderate risk
Category 4
Low risk
Category 5
Very low risk
For more information on how sealed sources are categorized, consult the CNSC website.
By the end of 2017, the NSSR contained information on 112,543 radioactive sealed sources in Canada. The SSTS actively tracks Category 1 and 2 sources. In 2017, 6,260 Category 1 and 56,970 Category 2 sources were tracked. The remaining 49,313 in the NSSR were Category 3, 4 or 5, which are not subject to mandatory tracking for every movement.
Sealed Source Inventory Trends
The number of sources located in Canada increases every year, mainly due to source manufacturers accepting returned sources for recycling, reuse and long-term storage. Figure 1 shows the total number of sealed sources, as well as the number of sealed sources in each category, that were accounted for in Canada on December 31, 2017. In 2017, there was a 9% increase in the number of high-risk sources compared to 2016, with the majority of the increase coming from the production of Category 2 sources. The increase in Category 3 sealed sources was primarily attributed to the return of sealed sources no longer suitable for use in prescribed equipment and to the decay of Category 2 sources held by licensees.
2013 | 2014 | 2015 | 2016 | 2017 | |
---|---|---|---|---|---|
Total sources | 66139 | 79077 | 92831 | 100996 | 112543 |
Category 1 | 3993 | 5734 | 6748 | 6273 | 6260 |
Category 2 | 32466 | 39167 | 45673 | 51501 | 56970 |
Category 3 | 24242 | 28701 | 34899 | 37675 | 43784 |
Category 4 | 484 | 224 | 200 | 293 | 258 |
Category 5 | 4954 | 5251 | 5311 | 5254 | 5271 |
Performance measures and verification
To gauge the effectiveness of the SSTS and verify the accuracy of the data in the system, CNSC inspectors physically cross-reference SSTS data against licensees’ actual inventory of sealed sources. Routine CNSC compliance inspections include requirements to verify sealed source tracking information. Inconsistencies are immediately addressed to ensure accuracy in the data. Typically administrative in nature, these inconsistencies may include errors in source serial numbers and reference dates, or the use of non-standard terminology when identifying sealed source assemblies.
In 2017, 133 inspections were conducted. Of these, 130 (98%) were found to be compliant and 3 (2%) were found to be non-compliant. The licensees that were initially found to be non-compliant have adequately addressed the issues identified during their inspections. The non-compliances included licensees not providing notification of SSTS transactions within the required time frame as per their licence conditions, and not up-to-date tracking information.
For more information on inspection results of Canadian licensees using nuclear substances relative to doses to workers, radiation protection, operating performance and sealed source security, refer to the annual Regulatory Oversight Report on the Use of Nuclear Substances in Canada.
Event mitigation
Licensees must immediately report lost or stolen nuclear substances to the CNSC and must also submit descriptions of any actions taken or proposed to recover missing nuclear substances. The CNSC investigates every such event and informs local, national, and international stakeholders who may assist with recovery. A list of events involving sealed sources can be found in the Lost or Stolen Sealed Sources and Radiation Devices Report.
The International Nuclear and Radiation Events Scale (INES) is a tool for communicating the safety significance of nuclear and radiological events to technical communities and the public. Every event reported from the commercial, academic and research, industrial, and medical sectors is classified in accordance with the INES, based on its safety significance rating. Of the following events, only one event was rated at INES Level 1 (anomaly). All other events were rated at INES Level 0, which are considered below scale and have no safety significance.
Figure 2. INES rating descriptions
A total of 19 sealed sources were involved in 11 events in 2017 (15 lost sources, 2 stolen sources and 2 recovered sources). These sources were classified as Category 4 or 5, which are low- to very-low risk sources.
2013 | 2014 | 2015 | 2016 | 2017 | |
---|---|---|---|---|---|
Lost/stolen | 14 | 13 | 16 | 12 | 10 |
Found | 3 | 3 | 1 | 3 | 1 |
Notes for figure 3:
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Transaction statistics
The NSSR is populated by licensees reporting their transactions via the online SSTS interface or by other means (such as fax, email or regular mail). Figures 3, 4 and 5 show transactions entered in the SSTS in 2017, statistics for import and export of sealed sources, and the percentage of online SSTS transactions from 2013 to 2017, respectively.
Import | Export | Exchange | Create | Change | Cancel | Transfer | Receive | |
---|---|---|---|---|---|---|---|---|
Transactions | 14858 | 18491 | 3484 | 16514 | 9975 | 255 | 5864 | 5735 |
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A total of 75,176 sealed source transactions were recorded in the SSTS in 2017, which represents a 15% increase over the number of transactions recorded in 2016.
2013 | 2014 | 2015 | 2016 | 2017 | |
---|---|---|---|---|---|
Number of sources imported into Canada | 12218 | 14307 | 14924 | 11577 | 14858 |
Number of sources exported from Canada | 14171 | 19047 | 17029 | 17311 | 18491 |
Users of nuclear substances in Canada routinely import and export sealed sources in accordance with their licences. There was a 7% increase in the number of exports, and a 28% increase in the number of imports in 2017 over 2016.
2013 | 2014 | 2015 | 2016 | 2017 | |
---|---|---|---|---|---|
Percentage of Web transactions relative to number of transactions | 88 | 94 | 93 | 95 | 94 |
In 2017, 94% of all transactions were done via the SSTS Web portal, a proportion that has remained steady since 2014.
Licensees’ continued use of the SSTS indicate that its implementation, as well as that of the NSSR, has been effective, and that Canada is maintaining its commitment to the Code of Conduct on the Safety and Security of Radioactive Sources.