
CKML

CKML was a 50-watt radio station owned by Atomic Energy of Canada Limited through licensee "The Security Systems Coordinator, Chalk River Laboratories" which operated at 530 kHz on the AM band in Chalk River, Ontario, Canada. The station is designed solely to broadcast emergency information in event of an accident at the laboratory.
The station was approved by the Canadian Radio-television and Telecommunications Commission (CRTC) in 1998. CKML, is not considered as a continuous broadcasting station. The service is tested for one hour each month and, once a year, a two-hour emergency exercise will be carried out. In a real emergency situation, the service could be used for many hours.
The "ML" in the CKML callsign refers to Mark Ling of Chalk River Laboratories. 
According to the June 2020 issue of the Canadian Radio News Facebook page, CKML is off the air. There were no licence renewals issued after the expiry date in 2012.