Rating definitions

Ratings are based on a comprehensive assessment of inspection results, event reports, desktop reviews and other regulatory oversight activities.

Safety performance ratings

The performance ratings used to report on the safety of Canada's nuclear power generating sites are defined as follows:

Satisfactory (SA)

Licensee meets all of the following criteria:

• Performance meets CNSC staff expectations.
• Licensee non-compliances or performance issues, if any, are not risk-significant.
• Any non-compliances or performance issues have been, or are being, adequately corrected.

Below expectations (BE)

One or more of the following criteria apply:

• Performance does not meet CNSC staff expectations.
• Licensee has one or more risk-significant non-compliance(s) or performance issue(s).
• Non-compliances or performance issues are not being adequately corrected.

Unacceptable (UA)

One or both of the following criteria apply:

• Risk associated with a non-compliance or performance issue is unreasonable.
• At least one significant non-compliance or performance issue exists with no associated corrective action.

Rating methodology

The rating assigned to each safety and control area is based on a comprehensive assessment of inspection results, event reports, desktop reviews and other regulatory oversight activities. CNSC staff consider the significance, frequency and overall impact of findings, as well as relevant performance trends.

Step 1: Identify findings

Findings are identified for each specific area using information from sources that include inspections, compliance assessments and desktop reviews. Each finding is assessed against established compliance criteria for the applicable specific area, which measure the degree of conformity with applicable regulatory requirements.

Step 2: Assess findings

CNSC staff evaluate the findings against applicable compliance criteria and assign one of five possible finding assessment categories: High, Medium, Low, Negligible, or Compliant. The assessment is based on the degree to which the finding impacts the effectiveness of the specific area, as defined in table 1.

Table 1: Finding assessment categories

Category	Definition
High	Major negative impact on effectiveness of safety and control measures in the specific area; evidence of breakdown
Medium	Significant negative impact on effectiveness of safety and control measures in the specific area
Low	Small negative impact on effectiveness of safety and control measures in the specific area
Negligible	Insignificant impact on effectiveness of safety and control measures in the specific area
Compliant	Evidence that the specific area is operating effectively and meets applicable regulatory requirements

Note: Risk-significant means that the issue has the potential to adversely affect safety, security, safeguards, environmental protection, or regulatory compliance to a degree that warrants increased regulatory attention.

Step 3: Rate the safety and control areas

For each of the 14 safety and control areas (SCAs), CNSC staff consider the relevant findings together with overall licensee performance to determine the SCA rating, in accordance with CNSC-developed guidelines. Findings are assessed in the context of the performance objective for the applicable SCA. The effectiveness categories assigned to findings within each specific area are then considered collectively to inform an SCA performance rating of satisfactory (SA), below expectations (BE), or unacceptable (UA) (see safety performance ratings).

Related links

• Regulatory oversight report for Canadian nuclear power generating sites
• Safety and control areas