During a search for PG&E info I came across a posting (by PG&E I think, on the yahoo site) saying that Diablo Canyon nuke had powered down to 50% because of "ocean swells" The link is to an occurance on Nov 19, and the other day I saw that the nuke had gone 50 about two or three weeks previous.

Does anyone understand this? Diablo uses ocean water for cooling, yes? But how does ocean swells compromise safety/production? Is this for real or is it a cover story from sinister Y2K testing or...? http://biz.yahoo.com/rf/991119/1z.html

-- johno (jobriy2k@yahoo.com), November 22, 1999

Answers

Don't know much about nuke plant design, but if the Diablo Canyon plant is anything like the one on the coast of New Hampshire, then it _may_ be affected. The Seabrook Station Nuke plant when it was built was the 'latest and greatest' nuke plant built in the country at the time. It had for cooling two immense underwater pylons sunk off the coast to provide the water for the plant, one for intake, the other for exhaust. If the Diablo Canyon plant has the same design, then maybe the tidal swells may affect the abilty of the plant to successfully exchange the seawater. The design raised a lot of havoc prompting the formation of a 'ecological terrorist group' called the Clamshell Alliance that protested the 2-3 degree rise in the coastal water temperature as a result...they though it would destroy the eco- system.

Off topic, one of the most bothersome things about that nuke plant is that it was supposed to be a twin reactor plant, and that the construction of #2 was halted _supposedly_ before the second reactor was plugged in or installed. Sure hope so, as when looking at the plant, one of the reactor domes is this nice hardened concrete dome, the other, a rusting amalgamation of girders and superstructure that has been exposed to the salt air for over 15-20 years...sure hope the thing (#2) isn't functional...I mean how long can structural steel be exposed like that before it collapses under its own weight?

-- Billy-Boy (Rakkasan@yahoo.com), November 22, 1999.

Indirect cooling. More than likely the seawater is used to cool the secondary loop. Reactor heats primary, primary through heat exchangers heats secondary steam, steam runs turbine, secondary steam is condensed by sea water before being pumped back to heat up. None of the loops comes into physical contact with the others and is constantly monitored to ensure this. On a conventional plant we ran into this same problem when the river water used as a heat sink to cool the turbine water became so warm that enough efficiencies where lost to reduce the max allowed turbine load (power output).

-- squid (Itsdark@down.here), November 22, 1999.

The NRC made a special ruling that for that part of the country containment vessels were no longer needed. Something about the country needing more space for farming. Unit 2 is presently operating at 4,400 degrees farhenheit and could supernova at anytime.

Many plants in construction did not receive the licensing our became prohibitively expensive. There were two choices retro-fit for conventional combustion power plant or drop and lock.

-- squid (Itsdark@down.here), November 22, 1999.

Can't say specifically on this one, won't guess.

I'll look at what the industry magazines report, but those come much later than this kind of media report......

-- Robert A. Cook, PE (Marietta, GA) (cook.r@csaatl.com), November 22, 1999.

Thanks for the info. "LOS ANGELES, Nov 19 (Reuters) - Pacific Gas and Electric Co. said Friday that both Units 1 and 2 at its Diablo Canyon nuclear power plant were 50 percent power and were being ramped down due to ocean swells," is how the story leads.

If you read this and are a PG&E customer, I have a good essay on the company, "Connecting with PG&E," on my website www.homestead.com/buttecounty2k/PGandE.html with other info too. News today from Gridley, a small agricultural town north of Sacramento. Story reports their municipal electric company is Y2K OK, just as long at the power from PG&E keeps coming through the transmission lines. Pray for Gridley.

-- johno (jobriy2k@yahoo.com), November 22, 1999.

Gee, Johno, your little note here at TB2000 (and electrifying link) has given me such a feeling of confidence about my beloved PG&E, provider of the juice I'm using to write you this thank you note....ah yes, I shudder to think of all the other pooor citizens of the world being deprived of having such an outstanding utility company, and a good bank of lawyers to see they never have to be held responsible for their behavior.

-- Queen of Hearts (alice@wonder.land), November 22, 1999.