Mexico to uprate its sole nuclear power plant up to 1600MWe.

[NNadir]

LEVALLOIS PERRET, France--(BUSINESS WIRE)--Regulatory News:

Alstom (Paris:ALO), in consortium with the Spanish utility Iberdrola, has just signed a contract with the state-owned utility Comision Federal de Electricidad (CFE) to modernise the Laguna Verde nuclear power plant located in the state of Veracruz, in Mexico. The total order value is estimated at approximately 470 million euros, of which Alstom’s share is around 150 million euros.

Alstom’s scope of supply is for the full retrofit of two steam turbines, each with one high pressure and two low pressure cylinders, and the supply of new generators. Consortium leader Iberinco, the engineering and construction business of the Iberdrola Group, will supply the balance of plant.

The project will increase the current installed capacity of the plant by 20%, from 1,350 to 1,634 MW. The work will begin on 2 March 2007 and is scheduled for completion by 2010. Laguna Verde is the country’s only nuclear power plant, and the refurbishment work is part of CFE’s strategy of optimising all its energy resources and maintaining a diversified and independent energy supply in the country.

http://home.businesswire.com/portal/site/google/index.jsp?ndmViewId=news_view&newsId=20070301005868&newsLang=en

[nealmhughes]

1. Laguna Verde is a GE Boiling Water Reactor complex, i.e., there are 2 reactors and turbines.

That is why two turbines are being retrofitted, each reactor has one steam turbine supplied directly from the reactor, i.e., not through heat exchangers.

The water in the reactor boils, is collected at the top through a series of moisture separators and driers and sent through a long loop into the turbine building. The long loop is to ensure that at least 17 secs pass before it gets to the turbine, allowing for the decay of Nitrogen that became radioactive during its time in the reactor.

The control rods are controlled from the bottom instead of the top as in a pressurized water reactor, and are water hydraulic operated instead of electric. Once gross adjustments of reactivity are achieved and criticality maintained through the control rods, flow rate through the reactor mainly controls reactivity, along with the negative temperature coefficient of reactivity (-alpha T). When flow is increased, the amount of bubbles on the fuel plates are swept away and thus the ratio of water/steam is increased towards the favor of the water, providing more moderation of the neutrons to make them thermal neutrons and so more likely to accept a neutron into the U and fission.

After the steam is condensed, it goes into reheaters where it is warmed up and sent back to the reactor as feed/coolant, thus providing a single loop of cooling and steam generation. There are 2 high pressure injection (steam powered) injection pumps and 2 low power ones (electric) to cool down/feed the reactor in the event of a leak. In addition, there is an emergency boron poisoning system that will flood the reactor with borated water and shut down any reaction should the control rods not insert. The entire thing is a very elegant design, and very efficient, as there are no steam generators and the likelihood of a cold water accident are minimalized in comparison to a PWR.

[NNadir]

2. Thanks for the description. I learned several things.

I didn't know the reason for the length of pipe between the turbines and the core. I just checked the table of nuclides and learned that N-15 has a relatively high capture cross section, 4.6 barnes at 0.025 eV. To be honest, I never realized that. Now that's interesting. I wouldn't think that it was much of a problem, since the natural abundance of N-15 is so small, but apparently it is enough of a concern to lengthen the pipes.

My understanding - and I have no direct experience with reactor operations - is that BWR's have a drawback inasmuch as radioactive materials <em>other</em> than nitrogen can accumulate in the turbine loop. Is this much of a concern?

I knew that Laguna Verde was a complex of two reactors and worded it badly.

Whatever you want to say about PWR's, they have a rather remarkable safety record overall.

Thanks gain though. I appreciate the information you provide.

[nealmhughes]

3. No, they are amazingly clean. The feed water is kept on a steam blanket which

keeps a lot of gases out. There is no read crud problem, either. The condensors being at vacuum keep the condensate gas free to a large degree, then steam blanketing the water and keeping it in a closed loop through the reheaters to the reactor is an immense help.

PWRs are much "dirtier" in my operational opinion, when constrasted to BWRs. The ease of increasing power by the variable speed feed/coolant pumps is part of that and I know of no radiation areas in the turbine bldg. in a BWR or a PWR for that matter! Now the crud accumulation on the SG tubes end plates is tremendous over time. The fact that a very complicated SG chemistry is needed to control corrosion says a lot about PWRs also, while it is an all voilatile system for BWRs.

I worked at Ft. Calhoun, a CE PWR for 3 years and hated it compared to that beautiful BWR I helped start up and do low power testing on at Shoreham! I was in the control room when Shoreham first went critical and was Control Room Communicator and got to call the NRC, the board of LILCO and issue the press release to the world. I'm sure they loved my deep southern accent on the radio on LawnGuyLand! Sunny Lom was withdrawing the rods, Joe Guitterez was the CR supervisor, the shift supervisor was Tony Mattesich and his asst. was Rick Reeves. Remember it like it was yesterday...

[NNadir]

4. Well I remember Shoreham going critical too.

I sulked a lot.

That's a sad story, the saddest in the world from my perspective because I was so damn wrong.

Did you happen to look at Phantom Power's map of Long Island with a seven meter sea level rise, by the way? It will be a big problem in "Lawn Guy Land," especially south of Sunrise Highway.

I really like that locution by the way. I was raised on Long Island, and was there way back in the days when a house could still be covered with potato bugs and stayed until it was one giant strip mall, more or less. I still have family all over the Island, including some on the South Shore.

But let's talk reactors.

Of course, unlike you, I have never operated a nuclear reactor, but I still note that the PWR program is a huge success and is still is the most widely used reactor type in the world by a long shot. From my perspective it's not PWR vs. BWR but nuclear vs coal. Both types, as you know, are featured in the Gen-III profile, the AP-1000 and EPR on the PWR side, and the ESBWR and the ABWR on the BWR side. I think the ABWR is working out real well over in Japan but the EPR and AP-1000 are still, of course, not standard issue but I think they will be.

For the last several months I have been in contact with a lot of nuclear professionals for some reason and I am learning the finer points. I'll take your word for it that a BWR is more fun than a PWR.

I would have thought that a cracked fuel rod in a BWR might cause contamination with say, iodine or xenon isotopes travelling through the loop in a BWR's turbine, but maybe that's real uncommon, I don't know. What about tritium?

(Mind you, I would understand this to not be the show stopper it might be in some imaginations, but I thought it would at least be an issue.)

This is no reflection on you, of course, but the management of LILCO were a bunch of really pathetic people. They botched public relations awfully. We in the anti-nuclear movement of the time were a bunch of assholes, but frankly, I really think that the LILCO folks were throwing gasoline on the fire. They were really, really, really poor at communication. To my mind the best strategy to obviate the superiority of nuclear power is just to tell the truth. I'm not sure that the top management at LILCO understood that.

I'm not really excusing myself, but I am trying to put the situation in context.

[hunter]

5. That was my experience too... the utilities shot themselves in the foot...

... by being so evasive, and at times untruthful.

I'm not sure whether to attribute this to know-nothing public relations people, or the culture of secrecy in the field of nuclear energy that was implemented from the beginning with the Manhattan Project and continued with Cold War military projects.

The general publics' aversion to science and math and tendency to categorize things they don't understand in terms of good and bad magic, and the loss of faith we had in our government because of the war in Viet Nam, added to the volatility of the situation.

[eppur_se_muova]

6. "in terms of good and bad magic" -- nicely put. nt