Environment & Safety

Safety

The Rabbit Lake operation is one of Canada's safest mining operations. Rabbit Lake has systematic programs to identify, evaluate and mitigate risks and engage all workers and managers in development of a strong safety culture. These programs follow the international OHSAS 18001 model and have delivered excellent safety performance.

Full-time equivalent dose

(mSv/yr)
	2017
Rabbit Lake	0.65

Radiation Protection

Radiation risks are effectively managed at Rabbit Lake through a formal radiation protection program and dedicated personnel who ensure that doses to workers are as low as reasonably achievable. The program ensures that radiation protection is considered in the physical design of all facilities and operating procedures. It also provides for systematic monitoring of radiation in work areas and tracking the exposures of individual workers using a combination of monitoring devices and health testing. Radiation exposures at Rabbit Lake are far below the regulated limits.

Environmental Protection

Environmental protection at the Rabbit Lake operation is assured through an ISO 14001-certified environmental management system. These programs ensure that the environmental aspects associated with the facilities are systematically identified, controlled and monitored.

Environmental Monitoring

Comprehensive monitoring programs are in place at the Rabbit Lake operation to help protect the surrounding environment. Samples of water, air, soil, plants and fish are collected from numerous locations around the site and tested to confirm that environmental protection systems are effective. Monitoring results are submitted to federal and provincial regulatory authorities for review. Cameco also supports independent regional monitoring downstream of its Saskatchewan operations to ensure there are no cumulative effects on the regional watershed. The extensive monitoring undertaken at Rabbit Lake has identified no significant impact on the surrounding environment.

Rabbit Lake Monitoring Results

Treated Water Quality — Arsenic
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Metal Mining Regulations Limit (mg/L)	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
Rabbit Lake Level (mg/L)	0.0008	0.0011	0.0012	0.0013	0.0013	0.0010	0.0009	0.0007	0.0007	0.0007	0.0007	0.0007	0.0008	0.0010	0.0011	0.0013	0.0012	0.0011	0.0009	0.0008	0.0007	0.0008	0.0006	0.0007

Rabbit Lake Monitoring Results

Treated Water Quality — Copper
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Metal Mining Regulations Limit (mg/L)	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3
Rabbit Lake Level (mg/L)	0.0002	0.0002	0.0002	0.0001	0.0001	0.0002	0.0001	0.0002	0.0001	0.0001	0.0001	0.0001	0.0002	0.0003	0.0003	0.0004	0.0004	0.0003	0.0002	0.0003	0.0002	0.0002	0.0003	0.0002

Rabbit Lake Monitoring Results

Treated Water Quality — Lead
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Metal Mining Regulations Limit (mg/L)	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
Rabbit Lake Level (mg/L)	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009	0.00009

Rabbit Lake Monitoring Results

Treated Water Quality — Nickel
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Metal Mining Regulations Limit (mg/L)	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
Rabbit Lake Level (mg/L)	0.0022	0.0027	0.0019	0.0014	0.0011	0.0013	0.0016	0.0017	0.0016	0.0014	0.0015	0.0019	0.0018	0.0020	0.0015	0.0017	0.0013	0.0013	0.0013	0.0013	0.0013	0.0014	0.0012	0.0012

Rabbit Lake Monitoring Results

Treated Water Quality — Zinc
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Metal Mining Regulations Limit (mg/L)	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
Rabbit Lake Level (mg/L)	0.0004	0.0009	0.0005	0.0003	0.0003	0.0003	0.0004	0.0003	0.0003	0.0003	0.0003	0.0003	0.0004	0.0008	0.0003	0.0005	0.0003	0.0003	0.0003	0.0003	0.0003	0.0003	0.0003	0.0006

Rabbit Lake Monitoring Results

Treated Water Quality — Suspended Solids
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Metal Mining Regulations Limit (mg/L)	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15	15
Rabbit Lake Level (mg/L)	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	0.9	1	0.9	0.9	0.9	0.9	0.9	1	0.9	0.9

Rabbit Lake Monitoring Results

Treated Water Quality — Radium-226
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Metal Mining Regulations Limit (Bq/L)	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37	0.37
Rabbit Lake Level (Bq/L)	0.004	0.008	0.007	0.008	0.005	0.004	0.005	0.003	0.003	0.003	0.007	0.005	0.003	0.004	0.005	0.010	0.005	0.005	0.003	0.004	0.004	0.005	0.007	0.003

Rabbit Lake Monitoring Results

Treated Water Quality — pH
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Authorized Maximum pH	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5	9.5
Rabbit Lake Level pH	7.26	7.31	7.19	7.01	7.09	7.30	7.30	7.64	7.43	7.39	7.28	7.27	7.3	7.3	7.4	7.3	7.4	7.3	7.4	7.4	7.2	7.0	7.0	7.2
Authorized Minimum pH	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0	6.0

Rabbit Lake Monitoring Results

Treated Water Quality — Selenium
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Saskatchewan Ministry of Environment Limit (mg/L)	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6	0.6
Rabbit Lake Level (mg/L)	0.0024	0.0021	0.0024	0.0026	0.0022	0.0018	0.0021	0.0023	0.0021	0.0022	0.0023	0.0022	0.0022	0.0021	0.0025	0.0026	0.0029	0.0036	0.0031	0.0029	0.0026	0.0023	0.0019	0.0020

Rabbit Lake Monitoring Results

Treated Water Quality — Uranium
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Saskatchewan Ministry of Environment Limit (mg/L)	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5
Rabbit Lake Level (mg/L)	0.0713	0.0842	0.0408	0.0395	0.0332	0.0353	0.0530	0.0695	0.0610	0.0496	0.0340	0.0415	0.0383	0.0214	0.0198	0.0288	0.0300	0.0345	0.0316	0.0258	0.0305	0.0396	0.0243	0.0268

Rabbit Lake Monitoring Results

Treated Water Quality — Molybdenum
	Apr-17	May-17	Jun-17	Jul-17	Aug-17	Sep-17	Oct-17	Nov-17	Dec-17	Jan-18	Feb-18	Mar-18	Apr-18	May-18	Jun-18	Jul-18	Aug-18	Sep-18	Oct-18	Nov-18	Dec-18	Jan-19	Feb-19	Mar-19
Rabbit Lake Level (mg/L)	0.1055	0.1136	0.1848	0.2103	0.1784	0.1235	0.1220	0.1375	0.1543	0.1734	0.2328	0.1585	0.1575	0.1702	0.2015	0.1580	0.1578	0.1988	0.2034	0.1615	0.1843	0.1640	0.1130	0.1240

Rabbit Lake Monitoring Results

Ambient Air Quality – Annual Average Ambient Sulfur Dioxide (SO₂) *NOTE - Regulations replaced and standard revised on June 1, 2015; however for consistency, the old value is referenced for the 2015 reporting year. Reporting against the new value began in Q1 2016.*
	2012	2013	2014	2015	2016	2017	2018	2019 Q1
Saskatchewan Ministry of Environment Standard (ppb)	10	10	10	10	8	8	8	8
Annual Average (ppb)	3.2	0.5	0.9	3.1	0.0	0.0	0.0	0.0

Rabbit Lake Monitoring Results

Ambient Air Quality – Annual Average Ambient Total Suspended Particulate (TSP) *NOTE - Regulations replaced and standard revised on June 1, 2015; however for consistency, the old value is referenced for the 2015 reporting year. Reporting against the new value began in Q1 2016.*
	2012	2013	2014	2015	2016	2017	2018	2019 Q1
Saskatchewan Ministry of Environment Standard - see note (µg/m³)	70	70	70	70	60	60	60	60
Annual Average (µg/m³)	6.3	7.6	6.6	7.1	5.0	6.3	4.3	5.7

Environmental Incidents and Other Events

Environmental incidents and other events are reported to regulatory agencies as required by federal and provincial regulations.

Latest incident or event:

Date	November 18, 2018
Incident	Propane release
Details	At 6:45 am a Rabbit Lake lab technician noticed the smell of propane near the Environment and Health Lab. A Rabbit Lake maintenance employee in the area investigated the source at the main camp propane farm and made the necessary repairs.
Corrective Action	Personnel in the Environment and Health Lab were evacuated as a precautionary measure. It is expected that extremely cold overnight temperatures caused the incident. Provincial and federal regulators were notified.
Environmental Effect	1

Read more

Date	November 18, 2018
Incident	Propane release
Details	At 6:45 am a Rabbit Lake lab technician noticed the smell of propane near the Environment and Health Lab. A Rabbit Lake maintenance employee in the area investigated the source at the main camp propane farm and made the necessary repairs.
Corrective Action	Personnel in the Environment and Health Lab were evacuated as a precautionary measure. It is expected that extremely cold overnight temperatures caused the incident. Provincial and federal regulators were notified.
Environmental Effect	1

Date	April 16, 2018
Incident	Overhead power line contact
Details	At approximately 7:00 am, an operator was moving equipment at the Rabbit Lake airstrip when he inadvertently made contact with an overhead power line. This caused electrical breakers to trip. There were no injuries.
Corrective Action	The operator was able to safely remove the equipment from the power line. The power line was inspected, found operational and power was restored. Provincial and federal regulators have been notified of the incident.
Environmental Effect	N/A

Date	January 6, 2018
Incident	Fire alarm system activation
Details	The Rabbit Lake main camp fire alarm system was activated at approximately 3:05 pm. All camp residents were evacuated and the site’s emergency response team (ERT) was activated. The CNSC Duty Officer and CNSC Project Officer were notified.
Corrective Action	The ERT responded in accordance with emergency procedures and verified that it was a false alarm.
Environmental Effect	N/A

Date	December 3, 2017
Incident	Propane release
Details	At approximately 2:00 p.m. a worker reported the smell of propane while working near the Rabbit Lake environment and health lab.
Corrective Action	The propane supply lines were immediately isolated. The site’s emergency response team (ERT) was dispatched, restricted access to the area and then identified the source of the propane to be a seal on the pump. The equipment was removed from service for repair and a new pump is being installed. The cause of the incident remains under investigation.
Environmental Effect	1

Date	November 12, 2017
Incident	Propane release
Details	At approximately 9:30 a.m. a worker detected the smell of propane while working at the Rabbit Lake residential camp.
Corrective Action	The propane supply lines were immediately isolated, access to the area was restricted, and testing was conducted to identify the cause. The source of the release remains under investigation.
Environmental Effect	1

Date	September 27, 2017
Incident	Fire alarm system activation
Details	The Rabbit Lake main camp fire alarm system was activated on September 27, 2017 requiring response of the site emergency response team (ERT). Following investigation the ERT confirmed that it was a false alarm. Safety personnel completed a scheduled test of a camp hydrant in the afternoon, which may have created a drop in system pressure at camp, triggering the alarm. The CNSC Duty Officer was notified in accordance with CNSC reporting requirements.
Corrective Action	The ERT responded in accordance with emergency response procedures and verified that it was a false alarm.
Environmental Effect	N/A

Date	September 13, 2017
Incident	Fire alarm system activation
Details	The Rabbit Lake Mill fire alarm system was activated on September 13, 2017 requiring response of the site emergency response team (ERT). Following investigation the ERT confirmed that it was a false alarm. During maintenance on a fan, dust was released into the ventilation system, tripping a smoke detector and activating the fire alarm system. The CNSC Duty Officer was notified in accordance with CNSC reporting requirements.
Corrective Action	The ERT responded in accordance with emergency response procedures and verified that it was a false alarm.
Environmental Effect	N/A

Cameco Environmental Effect Rating

Level 1 - no measurable impact to the environment
Level 2 - negligible impact
Level 3 - short-term, seasonal impact
Level 4 - mortality of some species, but not affecting ecosystem function
Level 5 - impairment of ecosystem function
N/A - not applicable

Tailings Management

Tailings, or what remains of the ore after the uranium has been removed at the Rabbit Lake mill, is placed in the Rabbit Lake in-pit tailings management facility (RLITMF). The facility is built into the mined out Rabbit Lake pit and is designed to safely contain the tailings during continuing operations and after decommissioning. When operations cease, the tailings will become a dense mass and groundwater will flow through a previous envelope surrounding the tailings, rather than through them, to minimize environmental impact. Tailings from milling the original Rabbit Lake ore body are stored in an above-ground tailings management facility.

Decommissioning

Rabbit Lake has been in production since 1975. Five ore bodies have been mined on the site using open pit and underground methods. Inactive mining areas are reclaimed as part of continuing operations at Rabbit Lake under a site-wide reclamation plan. Detailed plans and financial guarantees are in place to provide for final decommissioning of the Rabbit Lake site when operations end. Decommissioning will include removal of all buildings and equipment and landscaping and re-vegetation of affected areas. All underground workings and other mine and mill facilities will be sealed off and secured. A monitoring program will be in place to ensure the sites remain in a secure and stable state for the long-term.

Environmental Assessment

All new mining developments and significant changes to existing operations are subject to environmental assessments to identify potential effects on the environment. A provincial environmental review of plans to expand tailings management capacity at the Rabbit Lake is under way. The proposed project would add tailings capacity through excavation of an additional pit to the north of the facility.

Regulatory Oversight

The primary regulator for the Rabbit Lake operation is the Canadian Nuclear Safety Commission (CNSC). The mine is also subject to regulatory oversight from several other federal and provincial agencies including Saskatchewan Ministry of Environment. Federal and provincial regulators conduct regular site inspections and audits to verify that people and the environment are protected. Uranium mining and milling operations in Canada are licensed by the CNSC.