Thursday, March 31, 2011

Lessons That Could Be Learned

Almost immediately after problems began at the tsunami-damaged Fukushima Dai-ichi Nuclear Power Plant in Miyagi, Japan, the pro/anti nuke debate flared up.  At the beginning, the two sides stuck to their long-held positions,  Opponents said look, nuclear power plants are dangerous, just like we warned.  Supporters said look, the plants shut down and everything is contained, just as we expected.  But when crisis in Japan got worse, with significant damage to the buildings housing reactors 1-4 from a series of hydrogen explosions, the pro-nuke side retreated somewhat.  Some will surely surge back with renewed vigor, because their support is more tribal than rational.  Others may never be as enthused as they once were.

I've had some more general lessons running around my head than the ones I identified in the previous post, but I haven't found a way to make it a coherent post out of them.  So below I have just listed them out, in order to capture them before some new crisis displaces them.
  1. "Is" is the wrong verb.  A lot of pro-nuke cranks are fond of saying, "Nuclear power is safe."  This reveals a significant confusion on their part, because it is absolutely clear that nuclear power isn't inherently safe.  Most large industrial objects are not.  Cars, planes, trains, tanks, ore smelters, oil rigs, coal mines, oil refineries, combines, bulldozers - all of them are in fact quite risky when not taken seriously on a continuous basis.  What the supporters should say instead is, "Nuclear power plants can be run safely."   I believe that statement is true.  I also believe that it is hard to make that sentence true.
  2. Tail risk is incomprehensible.  Our modern high-technology industrial civilization is a very recent occurrence in the history of our little blue planet.  As a result, accurate records about various geophysical phenomenon are very short, and probably non-existent for some types of events.  Scientists have become pretty good at teasing clues out of the geological record, but the risk to nuclear plants in many areas is still not quantified.  But even if it could be quantified, humans aren't good at assessing the numbers.  For instance, a flight on a first-world commercial airline is safer than driving, but many people still refuse to get on a plane.  Similar problems arise when talking about nuclear power plants. But in that discussion the risk is often either wildly over-estimated or completely dismissed, and neither is correct.
  3. Profit is corrosive to safety.  As I've said before, here and elsewhere, I do not trust private, profit-driven corporations to run nuclear plants safely.  The reason is that safety costs money.  Resources spent on safety frequently won't translate into profits, in either the short term or the long term.  But executives get rewarded for performance on a time scale that is relatively short.  The massive mismatch between when cost-cutting might backfire and when an executive gets to drive new Porsche means that it will almost always be in a decision-maker's interest to go for short-term rewards.
  4. Technology matters only somewhat.  When a safety discussion becomes heated, often people will join in to say that one reactor type or another is better, and if only that reactor had been used, this or that problem wouldn't ever happen.  But nothing can be made fool-proof, and the specifics of implementation and operation can render inoperable a safety feature in any design .  The organizational culture that surrounds the low probability, high impact nature of nuclear power plants is just as important as the technology that is in use.

Saturday, March 26, 2011

Open Letter: Vermont Yankee

Greetings Senators and Representatives,

I am writing you today about the re-licensing of Vermont Yankee Nuclear Power Plant in Vernon, Vermont. As things currently stand, I am opposed to extending the plant's lifetime.

While I am not opposed to nuclear power in principle, I do not trust a private corporation to run a plant safely. Entergy has not been honest, and given that the current corporate culture in the U.S. values profit and nothing else, there is no reason to assume Entergy will be honest in the future. If the company wants to turn Vermont Yankee over to a publicly-controlled not-for-profit entity, then I would not be opposed to having the plant run for an extended period - if it can be determined that it is safe to operate. By safe, I do not mean satisfying every reasonable and unreasonable fear of an anti-nuke zealot. Instead, a team of skeptical engineers and scientists should be given full access to the plant, and the latest inspection equipment to use. If, after conducting an analysis that is independently reviewed for quality, the team finds the plant to be safe, it could continue operating. I doubt my conditions will be met, or even considered, so I think the plant should be shut down.

Thank you for your time.

Postscript: I started writing this letter before the 2011 Tohoku earthquake and tsunami struck Japan, and the Fukushima Dai-ichi Nuclear Power Plant. I think the events there are relevant to Vermont Yankee, but do not automatically justify condemnation of the plant. Here is what I think we can take away from the crisis in Japan so far:
  1. Vermont Yankee is unlikely to experience an earthquake with as great a magnitude during the next 20 years (or 2000, or 200,000) because there are no active subduction zones within thousands of miles. But the intensity assumptions used in Vernon could be wrong, as they were for the area offshore of northern Japan. If the plant was not designed to withstand to meet a sufficiently high level of shaking, the plant should not be considered safe.
  2. While Vermont Yankee has absolutely no chance of suffering from a tsunami, a more extreme flood on the Connecticut River should be postulated, and the plant re-evaluated using higher water levels. The scenario I'm thinking of is a spring melt causing a breech of the Comerford Dam near St. Johnsbury. If safety systems would not stay operational with water at higher levels, the plant should not be considered safe.
  3. Spent fuel rods stored inside the reactor building should be moved to dry cask storage and away from the reactor as soon as possible. Existing casks may also need to be moved uphill away from new flood level expectations. Re-licensing should be made conditional upon moving fuel rods that are sufficiently cool - on top of everything else.

Sunday, March 20, 2011

A Program of Contrasts

Almost immediately after the accident at Fukushima Daiichi, Chancellor Andrea Merkel announced a temporary shutdown of Germany's oldest nuclear plants.  Counting one plant that had been shut down prior to the accident, the sixth of seven plants was shut down on Friday.  The Chancellor was accused by some of playing politics in making the decision, as there are elections coming soon in several Länder.  The current CDU-CSU-FDP government has previously stated support for keeping the currently operating reactors open longer, which is unpopular, and a reversal from the policy of phase-out that had previously been in place.

I think the shutdown was overly dramatic because of the relative geological stability of the region compared to Japan.  The seven plants represent about 8% of Germany's total nameplate electricity generation capacity, so there is the potential for shortages.  Only two plants with a total of two reactors are located on the coast: Brunsbüttel, which was already shut down, and Unterweser.  The first is a boiling water reactor built by KWU, and from what I can gather, it has a design similar to a General Electric BWR/3 with Mark-1 containment.  The other is a pressurized water reactor derived from a Westinghouse design.  Of the other five reactors, two more are BWRs of the same design as Brunsbüttel, including one that has been in long-term shutdown due to technical and safety problems.  The rest are PWRs similar to Unterweser.  They are all located inland on rivers.  Like all other coastlines, there is some risk of tsunamis on the shores of the North Sea.  But without a subduction zone nearby, massive coast flooding would only come from underwater landslides.

The French nuclear power industry is in stark contrast to the German one.  In the wake of the accident in Japan, no plants have been taken off line, despite four plants with fourteen reactors being situated on the coast.  After an early foray into building gas-cooled reactors, France switched decisively in the late 1960s to PWRs derived from Westinghouse designs, and built large plants with up to six reactors of the same design.  Germany built both BWRs and PWRs, and even mixed the types at two plants.  However, only in the former East Germany was a plant with more than two identical reactors built.  Germany experimented with more unconventional reactors types than France, though none of the plants were all that successful, and all have been shut down.  France put a lot of effort into sodium-cooled fast reactors, but the first and only commercial-scale plant of that type was a failure.  France only operates PWRs at this time.

The mostly likely explanation for the contrast between the two nuclear programs is the nature of the two countries' constitutions.  France is a unitary state, which means local and regional governments only have powers that are granted by the central government.  Germany is a federal state, and each Länder has the right to administer certain functions.  France has had one monopoly power generation company since 1946, whereas Germany currently has several companies.  (I have no insight into the history of the German power industry.)  I think the scale and centralization of EDF, combined with the French love for grand projects like the TGV, has lead to the dominant role of nuclear power in the country.  France also has two geographic advantages over Germany: it is much less densely populated, and it has a much longer coastline.  That certainly allowed greater flexibility for siting plants.  France was also never on the front line of the Cold War, so the prospect of war-damaged reactor was less likely (though I have no idea if the issue entered the minds of decision-makers in either country).

At first glance, nuclear power clearly "works" much better in France than in Germany.  But entirely left out of this discussion so far is the issue of pollution.  I have no idea how much nuclear waste exists in each country, how much has leaked into the environment, how well the high level waste is guarded, or anything else along those lines.  Without analyzing that part of the nuclear complex, no evaluation can be complete.  France has also been "lucky" in one regard, which is that the design it adopted appears to be safe at this point.  No doubt a lot of study went into the issue before the choice was made, but that was done in the 1960s, when the industry was only 10-20 years old.  The depth of knowledge was much, much less back then, and a wrong choice or a bad design could have ended up crippling the country if dozens of reactors had to be shut down at the same time.

Added 2011/03/20: Here's a list of Japan's reactors.

Added 2011/03/22: Here's an interview with the head of E.on, Germany's largest electric utility, talking about the problems the shutdown may create in the Germany grid.  Of course, it's quite possible that he's exaggerating or even lying to boost his company's fortunes.

Added 2011/03/27: Former Chancellor Helmut Kohl lays into Merkel a bit.

Saturday, March 19, 2011

Oh, We're at War Again?

I suppose I should say something about this, since it's quite likely that more people will die in the attacks on Libya that started this afternoon than from the reactor accident at Fukushima Daiichi.  But the insanity of getting involved in another conflict in a Muslim nation has left me a tad despondent.

I frequently make fun of people that don't care about politics or pay attention to the news, but that outlook makes a certain kind of sense.  The news is damn depressing.  Why is America involved in another military conflict, when there are still over 40,000 troops in Iraq and over 140,000 in Afghanistan?  Why are we talking about deficit reduction when unemployment is over 9% and underemployment is over 16%?  Why are we talking about cutting Social Security when it makes no contribution to the deficit?  Why are we talking about cutting domestic discretionary spending when eliminating every single bit of it would only cut the budget deficit in half?  And on and on and on.  I keep saying I will pay less attention, but I can't make myself do that.

Compulsive behaviors - I hates them.

Thursday, March 17, 2011

Will We Turn Japanese?

I really don't think so.  But that doesn't mean we shouldn't consider the possibility.  The massive earthquake and terrible, devastating tsunami that struck Japan last week are unlikely to hit the US, except in the Pacific Northwest and Alaska.  Those are the only places close to the US where there are subduction zones, which are a type of tectonic plate boundary that is responsible for the largest earthquakes, and most tsunamis.  Coastlines are also vulnerable to tsunamis caused by underwater landslides, which may or may not be initiated by earthquakes.   In the immediate region of a small slide, tsunamis can still be large.  Very large slides can cause tsunamis that affect entire ocean basins.  The frequency of landslide-induced tsunamis is unknown at this point, but the risk on the entire west coast is much higher than elsewhere, again because there are active plate boundries nearby. 

Here are the nuclear power plants in the US close to a shoreline:
  • On the West Coast, there are two nuclear plants with four reactors adjacent to the ocean: Diablo Canyon Units 1 and 2, and San Onofre Units 2 and 3.  Two additional reactors have been shut down and decommissioned: Humboldt Bay Unit 1, and San Onofre Unit 1.
  • On the Gulf of Mexico, there is one plant with one reactor situated on the coast: Crystal River Unit 3.
  • One Gulf region plant with one reactor is located in a low-lying inland region that may be affected by storm surges: Waterford Unit 3.
  • On the East Coast, only one plant with two reactors is situated directly on the Atlantic Ocean: Saint Lucie Units 1 and 2.
  • Six East Coast plants with nine reactors are located behind barrier islands: Seabrook Unit 1, Pilgrim Unit 1, Millstone Units 2 and 3, Oyster Creek Unit 1, Brunswick Units 1 and 2, and Turkey Point Units 3 and 4.  The islands and shallow lagoons behind them may or may not be large enough to stop a tsunami from flooding the facilities.  Millstone Unit 1 has been decommissioned.  Shoreham Unit 1 never operated at commercial levels, and has been dismantled.
  • Five more East Coast plants with nine reactors are located on tidal rivers at varying distances from the ocean: Hope Creek Unit 1, Salem Units 1 and 2, Indian Point Units 2 and 3, Calvert Cliffs Units 1 and 2, and Surry Units 1 and 2.  The locations may or may not be far enough upstream to be protected from tsunami-induced flooding.  Two additional reactors have been shut down: Maine Yankee Unit 1, which has been decommissioned, and Indian Point Unit 1, which is still standing.
The only way to determine if these plants are actually at risk is to model a flood event and quantify the sea level rise.  Simply looking at the height or distance from the shoreline isn't enough.  The specifics of the coastline and bathymetry at each location can have significant effects on the run-up.  After that task is done, the containment structure and safety systems can be analyzed to see if they would remain intact and operating.  While this has certainly been done already for each plant, the question is whether it has been done with the right assumptions.  For instance, the plants on the northeast coast of Japan assumed the subduction zone offshore would not produce anything greater than a 8.0 earthquake.  That turns out to have been wrong, and the resulting tsunami was underestimated as a consequence.

Equally important as redoing analyses is actually verifying the safety systems work.  TEPCO, the owner/operator of Fukushima Daiichi, has been accused of not verifying the functionality of some of the safety systems.  Whether that is true will be worked out over the next few months.  But there should be another round of testing of each plant in the US regardless of the outcome.

Tuesday, March 1, 2011

The District Lines

One favorite pastime of transit nerds everywhere is making fantasy maps.  The Washington, D.C., area transit and development bloggers are no exception.  The four most prominent designs are those created by Greater Greater Washington, Beyond D.C., TrackTwentyNine, and The Transport Politic (a blog which isn't strictly about DC.)  GGW's plan extends all the way to the far side of Baltimore, which is reasonable considering how much of the area between the two cities has already been developed.

An idea common to most of the plans is to build a new tunnel for Metro's Blue Line through downtown.  It and the Orange Line currently merge at Rosslyn, and the tunnel under the Potomac River is one of the busiest sections of the system.  In order to relieve the "Orange Crush" - which will only get worse when the Silver Line is completed - the current Blue Line would stop at a new set of platforms in Rosslyn.  It would then go under the river to the west of the existing tunnel, and turn east under M Street in Georgetown.  Early proposals for Metro included stops in Georgetown, but they were dropped due to geography.  The new tunnel would then proceed under M Street through downtown, and by various paths proceed to cross the Orange Line again near RFK Stadium.

The plans also attempt to deal with less immediate capacity crunch in the Yellow Line/Green Line joint tunnel between the junction under the Southwest Waterfront and Gallery Place, which is a transfer station for the Red Line.  There's less agreement on what to do for this problem.   Solutions include a constructing separate tunnel for the Yellow Line to the west of the existing tunnel, or constructing a entirely separate line from Alexandria into downtown.

All of the plans have a significant shortcoming: they don't address the capacity issues on the Red Line, which is currently the busiest in the system.  Union Station sees the greatest number of riders entering or leaving in the system because of transfers from Amtrak or the MARC and VRE commuter rail systems.  Passengers switch to westbound Red Line trains to complete their journeys in the morning, and reverse the pattern in the afternoon and evening.  The line also receives heavy ridership from the northwest (timetable west), though that is moving in the opposite direction.

Below is my entry into the MetroRail expansion competition, which can also be seen in a slightly different form on GMaps.  My plan includes the idea of having separate platforms in Rosslyn and a new tunnel into downtown, but differs from the others on where the tunnel should go on the other side.  Instead of joining the existing path of the Blue Line east of the Anacostia, my proposed tunnel would split in two.  One branch would join the Red Line north of Union Station, and the other would proceed south of Union Station, pass east of the Capitol, and join the Green Line just south of Navy Yard.  This configuration would accomplish two things.  One is it would free passenger capacity heading west from Union Station, and a lesser amount eastward from Dupont Circle.  Most trains coming from the west end of the Red Line would terminate just north of Union Station, where ridership falls off significantly.  The other is it would provide a path for north-south travel outside of downtown.  Stations on the new line would be connected via tunnels to existing stations at Dupont Circle, Mt. Vernon Square, Union Station, Capital South, and Navy Yard.  The currently proposed connection between Farragut West and Farragut North, and the one between the two major transfer stations at Metro Center and Gallery Place are also shown.

One problem with building a new tunnel from Rosslyn through downtown is that it would potentially create a train throughput issue from the Pentagon on south to King Street.  My solution here would be to once again keep the lines separate.  In the short(er) term, trains could be simply turned at the Pentagon station, with a couple of extras kept on pocket tracks southwest of the station.  But in the longer run, I propose that a new line be built from the Pentagon south to join up with the existing Blue Line near Van Dorn Street.  While the I-395 corridor is certainly not urban and walkable, there has been considerable development along it.  Areas of increased density include Shirlington, the Skyline area north of the highway between King Street and Seminary Road, and the Landmark/Cameron Station area.  The current Van Dorn Street station is near the southern end of the built-up corridor, but it isn't easily accessed except by residences and offices immediately adjacent to it.  I propose stations at Shirlington, King Street, Seminary Road, Landmark Mall, and Edsall Road.  The new line would be constructed with a mix of aerial structures and tunnels.

The last piece necessary for my overall plan is a new connection between the Green and Yellow Lines south of L'Enfant Plaza.  Currently, trains of the Green and Yellow varieties can only travel north at the junction under the Southwest Waterfront.  I propose adding a new connection so that trains could travel from east to west and west to east at that location.  Connections could potentially added at a few other locations, though the added flexibility might not really be all that useful in those instances.

Close to downtown are two frequently discussed infill stations, one at Potomac Yards and another near the Jefferson Memorial.  The former is already being planned.  It potentially has great utility - if the NIMBYs in Alexandria allow enough density on their portion of the Potomac Yards site.  Arlington County has already developed a high-density master plan for the area north of Four Mile Run, but that may not have good access to Metro if the new station is positioned too far south.  The second new station would be a nice-to-have addition that would give tourists another point to access the system and give DC residents better access to East Potomac Park.  A third infill station on Cameron Run between King Street and Van Dorn Street on the Blue Line is also shown, though I haven't studied it yet.

Around the edges are some less important expansions.  The Metro was planned to be more like a commuter railroad than an urban transit system, with long suburban extensions and widely spaced stations outside of downtown.  I see no reason for fighting that history, so what I propose just extends the lines a little further to places that already have some amount of density.  Both ends of the Orange Line, the southern end of the Yellow Line, the southern end of the Blue line, and the eastern end of the Red Line each receive from one to four new stations, pushing the termini out as much as 10 miles.  The west end of the Red Line could potentially be expanded, but the route of least resistance would just duplicate MARC service.  On the north and south ends of the Green Line, there is no particular place to go that would generate many trips.  At the eastern end of the Blue Line in Largo there is a lot new construction, but it's not arranged in a way that could make use of an extension.

The diagram above shows one potential service configuration on the newly expanded system.  Each different line represents about a third of any one track segment's train capacity.  I can imagine a few other arrangements, but this one seems the best for the traffic demand as I understand it.  The names of new stations are in red.