To: flatsville who wrote (4170 ) 2/27/1999 6:09:00 PM From: John Mansfield Read Replies (1) | Respond to of 9818
'On Fri, 26 Feb 1999 23:29:21 GMT, "Jon Dough" <joe@microsoft.com> wrote: >> PECO Energy's Peach Bottom Unit 2 nuclear facility near York, Pa. >recently >> experienced a 7 hour lockup of the plant's primary and backup plant >> monitoring system computers during Y2k testing. The NRC weekly summary >of >> 2/12/1999 (http://www.nrc.gov/NRC/NEWS/WIR/week3.html) reports that >> operators lost the plant's Safety Parameter Display System (SPDS), >> Emergency Response Data System (ERDS), and 3d Monicore thermal limit >> monitoring system during the event. >> >> Engineers had taken the backup PMS computer off-line and had advanced the >> PMS clock to a year 2000 Date. This led to a lockup of the backup PMS, >and >> the system transferred to the primary, on-line PMS computer. The >engineers >> did not recognize that the system had transferred and, believing that the >> original command was not accepted, again advanced the system clock, >causing >> the primary PMS to lock up also. Several initial attempts to restore the >> PMS computers were unsuccessful, and operators determined that this >> constituted a major loss of emergency assessment capability. The PMS >> computers are not Y2K compliant, but the engineers believed that this >would >> not impact the testing. Operators did not expect the testing would affect >> the on-line PMS computer. PECO Energy plans to perform a full root >cause >> analysis of this event. >> >> In other nuclear Y2k news, Mr. William D. Travers, NRC Executive Director >> for Operations testified before the Senate Subcommittee on Clean Air, >> Wetlands, Private Property and Nuclear Safety Committee on Environment >and >> Public Works on 2/24/1999 that, "To date, the NRC staff has not >identified >> or been apprised of any Y2K problems in nuclear power plant systems that >> directly impact actuation of safety functions." (ref: >> (http://www.nrc.gov/NRC/Y2K/WDTY2K.html) >> > >This quote is *still* correct, loss of SPDS does not impact the safety >function of a nuke. At my plant, we would not be required to notify the >NRC unless it was lost for 8 hours. SPDS only provides backup data from >instruments that can be read elsewhere, it performs no automatic safety >actuations and would not stop the safe shutdown of a the reactor in any >manner. The human error was the disconcerting part. The date of the Peach Bottom report is 2/12/1999 (the problem actually happened on 2/9/1999). The date of Mr. Travers' testimony is 2/24/1999. While Mr. Travers may be splitting legally accurate semantical hairs with his testimony, it seems analogous to Bill Clinton saying...oh, never mind...you get the picture. I have no arguments with your statement that SPDS performs no automatic safety actuations and would not stop the safe shutdown of a the reactor in any manner. However, I have spent many lonely hours in the TSC during drills watching the EDO *rely* on SPDS for engineering assessments in accident scenarios. Besides the fact that some really weird things apparently happened in this event, the whole Peach Bottom incident validates all of my concerns regarding Y2k and nuclear facilities - not that Y2k could impact *safe shutdown systems* but that indications and display systems could provide inaccurate and conflicting data to the operators, resulting in improper response if a transient was to occur during the same timeframe. See "TMI2" for a description of what happens when operators believe inaccurate instrumentation and telemetry. If you need me to quote the relevant portions of the Kemeny Commission Report, I have it at my fingertips. -- Rick Cowles (Public PGP key on request) www.euy2k.com : Electric Utilities and Y2k Toll Free 1-877-503-2323 "ZAPPED" : A Household Video Primer for Dealing with Long Power Outages RealPlayer(tm) clip at: www.euy2k.com/video.htm