For attribution to a CS Energy spokesperson:
Unit C3 at Callide Power Station is currently offline for repairs until 30 May following an incident on the unit last Friday.
On 4 April, a significant clinker (hardened ash) detached from the internal boiler wall of Unit C3.
Clinker formation is common in coal-fired power stations. CS Energy has clinker management tools and practices in place to regularly detach clinkers from furnace tubes so they can fall to the bottom of the boiler for easy removal.
On this occasion, when the clinker detached, it resulted in a pressure spike within the furnace. Our initial assessment is that repairs are required to cladding and lagging on the upper section of the boiler.
No one was in the area at the time of the event and there were no injuries. The unit’s protection systems worked as design to shut down the unit.
CS Energy notified Workplace Health and Safety Queensland (WHSQ) on the day of the incident. Yesterday WHSQ approved for CS Energy to access the area.
Investigations and inspections are ongoing to fully assess what occurred and the repairs required to safely return the unit to service. Access is restricted to key personnel only.
Across all CS Energy power stations, we have strengthened clinker controls and are continuing proactive clinker deloads as guided by management tools. Access is also being restricted in boiler areas while clinker deloads are carried out.
Callide Power Station’s other three generating units, as well as Kogan Creek Power Station, are all online and available to support Queensland’s energy needs.
Background
Clinker deloads are common practice in the management of clinkers at coal-fired power stations. By reducing the load, it reduces the pressure inside the boiler, allowing the clinker to detach from the side and fall to the bottom of the boiler for easy removal.
Callide Power Station is comprised of two power plants, Callide B and C, each with two generating units (B1 and B2, C3 and C4).
Callide B has a capacity of 700 megawatts (MW) and is 100 per cent owned by CS Energy.
Callide C has a capacity of 848 MW. CS Energy (through our subsidiary Callide Energy Pty Ltd) owns Callide C in a 50/50 joint venture (JV) with IG Power. CS Energy operates Callide C on behalf of the JV.