There is a report about an incident at a Scottish nuclear plant which happened this last weekend at:

http://www.record-mail.co.uk/rm/stories/A3012804.html

The part pertinent to my question is:

"The astonishing situation - sparking fears of a Chernobyl-type reactor meltdown - happened after storms took out the national grid twice in the space of 12 hours.

The first time - at 11pm on Saturday - the emergency back-up generators in the nuclear plant switched on automatically.

But there were not enough staff on duty to manually reset them before the grid went down a second time at 11am on Sunday - leaving plant bosses helpless."

Since I believe it's possible that Year 2000 problems could create areas of grid instability(up,down,up,down)in this country, do emergency switches in our nuclear plants have to be reset manually after they trip in order to work a second time? Could we experience a problem similar to that in Scotland? I'm also wondering if this manual resetting is part of the reason why several utilities have reported they will have a full staff, with backups, at work over the rollover?

Many thanks in advance for any comments addressing this 'double trip' scenario.

-- Anonymous, December 30, 1998

Answers

A brief comment on the above news report:

My experience with the press and nuclear energy is that in a situation such as the above, they tend to "mix metaphors" and get the details wrong. I can't imagine such an inherent design flaw:

• Loss of offsite power (LOOP)
• Emergency diesel generators (EDG's) kick on automatically per design
• Offsite power is restored, EDG's are shut down
• Another subsequent LOOP, EDG's don't kick on automatically

- something isn't right here.

Either the story is wrong, the EDG's were shutdown improperly (human error), or there's a really bad design flaw. I can't see where staffing (or lack thereof) would have had a thing to do with the initiating events - it should have all been automatic. It will be interesting to see the followup report on this one.

As a sidebar, one of the interesting characteristics of all past significant events in the nuclear industry is that relatively minor problems tended to be exacerbated by incorrect human intervention, because the people controlling the plant didn't fully understand what was happening during the event.

-- Anonymous, January 01, 1999