Y2K simulation failures list; Netherlands site.greenspun.com : LUSENET : Electric Utilities and Y2K : One Thread |
I thought I'd seen all the reports of Y2K failures and simulation failures, many of them duplicated at various sites, but there were a few new ones I hadn't heard of on this list reported by Han van Doom, Y2K Solutions, Netherlands. If I just missed these and other readers are already familiar with them, my apologies. I also do not know what Mr. van Doom's validation criteria were for these reports.Link: http://www.xs4all.nl/~doornh/year2000/WARSTORY.HTM
"Cubine and Bruhn point to a case involving a turbine generator. The system used a pulse train temperature sensor reporting back to a programmable controller. The controller was counting pulses between two time stamps and assigning a temperature value. In doing a Y2K rollover test on the system, found that the assigned temperature value went to infinity at the year 2000, which immediately started the shutdown procedure."
"A Midwestern US fossil facility was testing a boiler feedwater control loop for date rollover to Year 2000. The control console date was set in a fashion similar to testing a PC - it was changed to 12/31/99, 23:58, and then powered down. A few minutes later, it was powered back up - with the only resultant problem being the year shown as 1980 (a typical older BIOS response). The logic loop (PLC and other instrumentation) continued to function normally. Boiler levels were simulated up and down to drive feedwater regulating valves; again, no problem. Then, the technicians reset the console clock to 12/31/99, 23:58, and did NOT power down. When the clock rolled over to 01/01/2000, there was no problem. The technicians powered down the console and then restarted it - and guess what happened? The console rebooted with a date of 01/04/80, the downstream PLC (which had not been powered down) apparently saw this as a significant mismatch with it's own clock (time as a function of integers rather than actual date), and interpreted this condition as a gross control failure. The feedwater regulating valves were driven shut, and the boiler trip logic was initiated (the 'fail safe' condition for the boiler). In a 'live' situation, the plant would have tripped."
1.Four Alcoa Steel Plants : 50% of control systems will fail
2.North Sea Expro (Shell-Exxon JV) Platform, Pipeline and Gas Plants 1.systems identified, 12% failure rate
3.BP Refinery, Grangemouth, UK, 1.systems identified, couldn't find vendor for 20 2.assessed, 3 will fail, 2 will cause shutdown
-- Anonymous, May 21, 1999
First there is no way to check any of this out. It's just a listing. However some of these stories are sooooooooooooooooo old that it does make you wonder. The one about the turbine sensor is old old old. It was orginally reported to be in an English generating station, and supposedly vetted by EPRI. However it than turned out to be simulation. What does that mean? Beats me. Was it a computer simulation? One done on the plant floor with equipment out of service? Done by the vendor? No one knows.The second story has also been around for a few years. No one has ever been able to "publicly" verify it. EPRI tried. It was always an "I was told this by some one who knows." kind of story.
Ditto the other stories. Unless it's something that can be veified I remain a skeptic. Or as was told to me in the strictist confidence by a friend of a friend who has a brother who's wife knows a man who use to be a neighbor until he moved and has an ex-brother in law who use to know someone who knew someone who did stuff: " It just may not be true". And you can quote me on that.
-- Anonymous, May 24, 1999