Significant Potential Incident Unauthorized Weld on Pressurized Water Line Timmins, Ontario, Canada October 17, 2011

SERIOUS INCIDENT REVIEW Equipment: Steam Generator 1 Time/Date: Reported date October 17, 2011 Location: Timmins, Micronizing Plant Conditions: Normal Running Conditions Workgroup: Maintenance Supervisor: Ray Drouin Manager: Yahia (John) Aoumer

Scenario description A boiler feed water leak was discovered on the 2” feed water piping between steam generator 1 thermizer and super heater 1.The employee informed the Process Technologist who was supervising another job in the boiler room. While discussing the repair options for the leak it was pointed out by the Millwright employee that a larger section of pipe should be replaced. He identified where a previous patch weld repair was performed. The employee then showed the Process Technologist the location of the weld repair. The patch weld repair was located on the side of the 2” boiler feed water line. This line routinely experiences temperatures in the 250 ˚F range and pressures in the operating range of 400 to 600 psi.

Risk Score= Consequence × Likelihood

Consequence Descriptors

Likelihood Descriptors LikelihoodLikelihood descriptionFrequency Substance Exposure ALMOST CERTAIN Recurring event during the life- time of an operation / project Occurs more than twice per year Frequent (daily) exposure at > 10 x OEL LIKELY Event that may occur frequently during the life- time of an operation / project Typically occurs once or twice per year Frequent (daily) exposure at > OEL POSSIBLE Event that may occur during the life-time of an operation / project Typically occurs in 1-10 years Frequent (daily) exposure at > 50% of OEL Infrequent exposure at > OEL UNLIKELY Event that is unlikely to occur during the life-time of an operation / project Typically occurs in years Frequent (daily) exposure at > 10% of OEL Infrequent exposure at > 50% of OEL RARE Event that is very unlikely to occur very during the life- time of an operation / project Greater than 100 year event Frequent (daily) exposure at < 10% of OEL Infrequent exposure at > 10% of OEL

What Happened Maintenance Leader found a small leak from a pressurized water line in the boiler room Maintenance Leader took it upon himself to patch weld the leak Maintenance Leader did not inform the Plant Supervisor of his actions. Immediate Response When Management becomes aware of the weld, the whole pipe is replaced immediately Incident rated as a Significant Potential Incident Taproot investigation begins.

Photos of the incident site and scene

Weld on pipe pipe removed and in the recycle bin in this picture

Winter Snap Chart

Mitigating Factors Employee eventually reported the welding job 9 weeks later to a Member of Management.

Contributing / Causal Factors No Preventive Maintenance exists for inspections on water/steam lines No Supervisory Personnel notified of leak Welding event does not get reported to Management Employee decides to perform repairs to water line

Root Cause & Corrective Actions