Today (Tuesday 13th February 2024) CS energy has released a detailed insight into what happened to the C4 unit that caused the major failure – linked to this Media Release:
The news article ‘CS Energy releases technical report into 2021 unit C4 incident’ links through to a number of items, including these two important ones:
18-page Report
There’s this 18-page ‘Technical Investigation Summary’ here:
Note that this is not the ‘Brady Report’
Animated Timeline
There’s also this animation on YouTube here:
Meanwhile in Victoria …
More to come on this already busy day in the NEM with an incident occurring in Victoria, Paul has been covering today.
Thankfully this came out on a quiet day with not much else going on, I’ll just settle in and read/watch it.
This report is shocking.
– Automatic changeover for Y protection inoperative, configured such that both X and Y redundant protection are powered from the same DC supply.
– Switching sequence has risk of interrupting DC power to plant, removing redundancy from critical systems, and all protection, was carried out while plant is running.
– No recovery/rollback plan or procedure for loss of AC power to, or failure of, the battery charger while DC system is operating without a battery is mentioned. Restoring DC supply from one of the batteries would have improved the situation.
The accompanying video also mentioned that operators did not ask Calvale to isolate the generator as they feared a steam valve leaking by. However, reverse power would suggest the grid was not providing a mechanical load on the turbogenerator, so isolating it isn’t going to make the situation worse.