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Software Update Shuts Down Nuclear Power Plant
Garabito writes "Hatch Nuclear Power Plant near Baxley, Georgia was forced into a 48-hour emergency shutdown when a computer on the plant's business network was rebooted after an engineer installed a software update. The Washington Post reports, 'The computer in question was used to monitor chemical and diagnostic data from one of the facility's primary control systems, and the software update was designed to synchronize data on both systems. According to a report filed with the Nuclear Regulatory Commission, when the updated computer rebooted, it reset the data on the control system, causing safety systems to errantly interpret the lack of data as a drop in water reservoirs that cool the plant's radioactive nuclear fuel rods. As a result, automated safety systems at the plant triggered a shutdown.' Personally, I don't think letting devices on a critical control system accept data values from the business network is a good idea."
I'd rather it shut itself down then suffer major failure.
What exactly do you find frightening about an automatic safety system doing exactly what it's supposed to in response to unusual input?
Secondly the software update did not respect the data in the nuclear control system and synchronized it to new initial data in the update on the other system! Not a good idea. In critical safety systems, you always practice an update before actually doing one.
I have no problem with a computer on the process control subnet reporting information to a computer on the business subnet.
I have a BIG problem with a computer on the business subnet being able to modify and corrupt data in a computer on the process control subnet.
"I can't dump data to the business side" is a reason to make a log entry and maybe sound a minor alarm. It's not a reason to shut down the reactor (unless the data is needed for regulatory compliance and the process control side isn't able to buffer it until the business side is working correctly.)
But if a business subnet computer can tamper with something as critical as a process control machine's idea of the level of coolant in a reservoir, it rings my "design flaw" alarms.
Is it ONLY able to reset it to "empty" as poorly-designed part of a communication restart sequence? Or could it also make the process control machine think the level was nominal when it WAS empty?
IMHO this should be examined more closely. It may have exposed a dangerous flaw in the software design.
Security flaws don't care if they're exercised by mischance or malice. If nothing else, this is a way to Dos a nuclear plant through a breakin on the business side of the net.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
The problem here is that the system didn't shut down because it detected an error in the data collection system, instead it incorrectly detected a problem that did not in fact exist and then proceeded to take action. While the engineer in me is fairly certain that the system is designed to always fail to a safe state (as in, any automatic emergency response couldn't accidentally make things worse - at least not without raising all sorts of alarms), it is still concerning that internal control systems can be so effected by external servers.
In the article they mention that the system wasn't designed for security (since it was meant to be internal) - but this isn't a security issue at all! Any sort of system that relies upon other systems should be designed to assume failure can and will occur in other systems - that is not to say that it needs to verify/evaluate incoming data to make sure it is "good", but rather that it can tell the difference between receiving data (such as current water levels) and receiving no data at all (system failure). Once it has that it can ideally automatically switch to a backup system, or do what it did here and enter a fail-safe state (the difference being that it does so while pointing out the actual problem and not a incorrectly perceived problem in a different part of the system).
And a shutdown, while incovenient, is not a catastrophe. In fact, it speaks well for the plant's safety that it did automatically shut down when faced with bad data.
India's accelerated thorium idea is also very promising.
The major problem I see with US nuclear power is the assumption that it is a solved problem and almost zero has been spent on R&D for decades. The "new generation" of reactors from Westinghouse and others is little more than 1960's white elephants painted green.
Yeah, so when a sensor breaks and stops sending in data, it'll keep running like usual, with maybe a small error code in the background. Cause, you know, that's how we want nuclear fucking powerplants to work.
I think you're missing the real point, which is that the central safety systems are being fed data from a 'business network'. What would happen if that computer had an issue that caused it to send the same data continuously even when the coolant level had really dropped? WHY are any safety systems receiving data from an insecure network?
It's bad enough that most reactors use regular PC's to do the data collection and reporting, given the security risks posed by such systems (especially if networked), but I never realized they would be so stupid as to feed data in the other direction like this!