Cameco’s uranium dioxide (UO2) plant was voluntarily shut down on June 30 to investigate an exceeded an action level for uranium emissions, a press release issued July 15 by the Canadian Nuclear Safety Commission (CNSC) states.

On June 29, in accordance with reporting requirements, Cameco notified the CNSC that it had potentially exceeded an action level from its UO2 plant and that its internal investigation was underway.

Action levels are set by licensees and are part of their radiation and environmental protection programs. These levels are early warnings of any process upsets and are set well below CNSC regulatory limits. Therefore, exceeding an action level does not represent a risk to the environment or to the health and safety of the public and workers, the release states.

On June 30, Cameco voluntarily shut down the UO2 plant to conduct its investigation to determine potential sources of elevated uranium emissions. Cameco advised the CNSC that it took corrective actions, including inspecting and cleaning of process and sampling equipment, implementing new maintenance procedures and comparing results from its in-house stack sampling with those obtained from stack sampling surveys conducted by an independent, third party.

On July 12, as requested by CNSC staff, Cameco submitted its report on uranium emissions from its UO2 plant main stack.

Based on the review of this report, the CNSC has determined that on June 29 the UO2 plant uranium emission rate was 7.21 grams of uranium emissions per hour (gU/h). Although this rate is well below the licensed limit of 150 gU/h, it is above the plant’s action level of 7 gU/h.

It is the CNSC’s view that further improvements to Cameco’s UO2 plant in-house stack sampling system and preventative maintenance program are warranted.

The CNSC has asked that Cameco submit its final investigation report, including the causes of elevated uranium emissions and the corrective actions that will be taken to prevent reoccurrence of the June 29 incident.

The CNSC has also requested that Cameco submit its consultants’ recommendations to improve the in-house UO2 plant stack sampling system.

At no time was there a risk to the health and safety of workers, the public and the environment.

The CNSC will continue its regulatory oversight of the facility, states the release.

via CNSC asks Cameco for report – Northumberland Today – Ontario, CA.