Julian
McKay's article was fraught with blunders (intentional) to attack CANDUs. He was listed as a "friend" of Energy Probe (probably Canada's biggest antinuclear corporation) back in 1984, wrote a series of four error-filled and biased anti-nuclear articles in the Ottawa Citizen in 1998, and was a political advisor to provincial NDP and Liberal parties. He is fervently anti-nuclear. Evidently to the point of being an embarrassment to the antinuclear industry, due to his complete misunderstanding of facts and his amazing claims.
CANDUs are typically connected to the grid when they are at low (~12% reactor power). The generators are run up and synchronized to the grid at very low (zero?) power, and the output to the grid is slowly increased (I saw a figure of ~1 MW/minute increase rate). Even with the reactor running at 60% (poison prevention mode) full power, the turbine-generator set would be synchronized at very low power and then loaded up slowly.
The reactors can be run so that the generators provide in-house electricity for pumps, controls, etc. The in-house load is in the order of 5 to 7% of full (gross) electrical output. For example, Darlington reactors are listed as 935 MWe gross, and 881 MWe net (94.2% net to gross ratio).
I don't know how the Bruce reactor generators were run on Thursday Aug 14 night. It is possible that hydro power was required for a limited time as the generators were decoupled from in-house generation, and then synchronized to the grid.
By the way, Pickering-4 is now synchronized to the grid, for the first time since April 2 1996, when it was shut for adding the enhanced shutdown system (and then that got delayed by the refurbishment process).
Darlington and Bruce B reactors have both atmospheric and condenser steam discharge valves (ASDVs & CSDVs), which are used to dump the reactor heat. CSDVs are preferred, as they recycle the demineralized water in the secondary side (ASDVs blow off the limited supply of demin water to atmosphere).
As for the Ottawa Citizen, it is not known for unbiased reporting on nuclear matters, nor is the National/Financial Post. The latter has exceedingly strong links to Energy Probe, which uses the Nat Post as a soap box for their "markets-can-solve-everything" philosophy.
There are several letters in to the Ottawa Citizen (letters@thecitizen.canwest.com), that I know of, including my own.
Interestingly, the Ottawa Citizen made a "Correction" in today's paper, as it was evident that McKay was completely ignorant and confused about xenon vs gadolinium nitrate poisoning (I'm surprised, given that he's 'studied' nuclear issues for so long). In today's paper:
<BEGIN QUOTE>
Correction
The Ottawa Citizen, Fri 22 Aug 2003
Page: A2 Section: News
A story on page A1 in Wednesday's edition about Canada's Candu reactors said the reactors' shutdown systems use gadolinium to "poison" the reaction process. In fact, most of the reactors use xenon, not gadolinium.
<END QUOTE>
Heartening, eh? How can one ever trust such a media source to report accurately on other subjects (e.g. health, politics, international, etc.)?
sighhhh
Morgan Brown
-----Original Message-----
From: JGinniver@aol.com [mailto:JGinniver@aol.com]
Sent: Friday, August 22, 2003 4:17 PM
To: cdn-nucl-l@informer2.cis.McMaster.CA
Subject: [cdn-nucl-l] erroneous reporting in the Ottawa Citizen
This week there have been a couple of misleading stories in the Ottawa Citizen. I have added the links below for those that are interested. The first on Wednesday, titled " How our nuclear reactors failed us" states for example "For cost and safety reasons, the four Bruce A reactors will likely never be restored to service.". This is despite the fact that approval was recently given to lift the Guaranteed shutdown state on one of the Bruce A reactors with it expected to return to service soon with the other unit that has recently been upgraded returning to service shortly thereafter. There are a number of comments about the design and operation of CANDUs which I'm not qualified to comment on although they seem at best overly simplistic and at worst a misrepresentation. I would appreciate feedback on some of these issues as my experience is restricted to Gas Cooled Reactors and the UK/Westinghouse PWR design. Particularly on the issue of increasing load and feeding this into the grid. I recognise that the Sizewell B PWR is able to achieve criticality and reach a steady state of reactor power at about 10 - 15% Rx power before running up the turbine and synchronising to the grid. Once the turbine is synchronised it is then possible to feed in a rate for the increase in generation and gradually increase reactor power and electrical output. Is this possible on a CANDU, I'm assuming - perhaps rashly - that even if the reactor is stabilised at 60% Rx power it does not have to synchronise the turbine and then load rapidly to an equivalent electrical output as suggested in the newspaper article. My assumption would be that while stabilised at 60% Rx power and de-coupled from the turbine excess heat is removed either through discharge to atmosphere, or through bypassing the turbine and feeding to the condenser. And that this process can continue while gradually transferring steam from bypass into the turbine. Any insight would be appreciated. The other article today continued to devalue the contribution of nuclear power to the recovery of Ontario's Power Grid.
http://www.canada.com/search/story.aspx?id=930a90cb-3faa-4568-928e-96ca540550c0 Wednesday 20 July 2003
The comments about Bruce "On a tour of the Sir Adam Beck facility in the southwest part of the province earlier this week, Ontario Premier Ernie Eves was told that the Beck hydroelectric generating stations helped restart several reactors that had been shut down at the Bruce facility on Lake Huron. " is at odds with the information published by Bruce Power on Friday 15th. The operators at Bruce stated "Within hours of the incident, three of the four units at the Bruce B generating station were reconnected to the provincial grid and are currently being dispatched at the direction of the Independent Electricity Market Operator (IMO).
Together, Units 5, 7 and 8 have 2,400 MW of electricity available when called upon by the IMO. As a result of the disruption, Unit 6 did shut down and will be returned to service as quickly as possible." Does anyone know whether the Bruce reactors did shutdown, and require external power supplies to re-start. Or is it simply that three of the reactors were stabilised at 60% Rx power, while de-coupled from the turbines and that external power was required to provide supplies to the plant while the turbines were returned to service? This would mean that electricity from Hydroelectric genertingstations did contribute to the return to (elctrical generating) service of the Bruce reactors, but not the restart of the reactors as indicated in the article.
http://www.canada.com/search/story.aspx?id=f8d0f592-a36f-4a9d-91e5-ce980415f8cd Friday 22 July 2003
Is this the norm for this paper? Anyone know who to direct comments on accuracy to?
Regards,
Julian Ginniver