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Tokyo Shinbun calculated the hypothetical amount of the remaining contaminated water, based on the data published by TEPCO on the amount of contaminated water transfer and the amount of water injection into the reactors. According to our calculation, about 100,000 tonnes of contaminated water should have been reduced to about 51,600 tonnes by September 13.

However, the latest estimate by TEPCO from the actual water levels in the basements is 81,300 tonnes, leaving 30,000 tonnes or so gap from the calculated amount.

So far, TEPCO has explained that the contaminated water is not decreasing as fast because of the rainwater. Around Fukushima I Nuclear Power Plant, there have been 3 heavy rainfalls since July. Part of the rain may have entered the buildings through the damaged rooftops. However, the contribution of rainwater to the water in the basements is not big enough to explain the 30,000 tonnes difference.

It has been pointed out before that the groundwater may be flowing into the basements through cracks in the basement walls, and now that possibility is even more heightened. We showed the result of our calculation to TEPCO, and they answered "The water may be flowing in in the order of 100 tonnes per day".

If the groundwater is indeed flowing into the basements, the amount of contaminated water to be treated will be further increased, necessitating the decrease of water being injected into the reactors. The work to wind down the accident may be affected in many ways.I don't know whether TEPCO means "100 tonnes per day per unit" or "100 tonnes per day per each building" or "100 tonnes per day at the plant".In the latest announcement on the contaminated water processing on September 14, TEPCO is processing about 1,500 tonnes per day.

Seafood, anyone? One of the problems of the release of radioactivity into a maritime environment is that is represents a cumulative food chain, from plankton consumed by larger organisms, as evidenced by mercury contamination of swordfish, none of whom swam around ingesting globules of the silvery metal. IRSN estimated that of the total amount, 82 percent had flowed into the sea by 8 April, adding that the Pacific was polluted at exceptional speed because the devastated Fukushima Daichi nuclear power plant (NPP) is situated in a coastal area with strong currents. If the IRSN report contained any good news, it was that the impact of the cesium-137 contamination on marine life in remote waters is likely to lessen later this year.  

The radioactive silver lining? Radioactive cesium-137 has a half life of roughly 30 years, so if the IRSN estimates are accurate, then my 2041 the Pacific’s aquatic life will only be subjected to a mere 13.55 quadrillion becquerels of radiation. This is not to suggest that Japanese will shortly be keeling over from consuming their sushi but rather, that for better or for worse, a significant amount of cesium 137 has entered the Pacific’s aquatic environment, and the long-term effects of low-level exposure on the population consuming Pacific seafood are unknown. Numerous tests since 1945, when before it  was believed that only massive bursts of radiation were hazardous to human health, have documented the insidious effects of long-term, low level radiological exposure to humans. Fukushima sits at the nexus where the Kuroshio Current, running northward off the eastern coast of Japan, collides with the cold subarctic Oyashio Current that flows southwards, circulating counterclockwise along the western North Pacific Ocean. Their interaction produces the North Pacific Current, a slow warm water eastwards flowing current between 40 and 50 degrees north in the Pacific Ocean. In the eastern northern Pacific, the North Pacific Current divides into the southern flowing California Current and the northern Alaska Current.

Well, if we can’t tax pollution, how about encouraging the use of clean sources by giving them subsidies? This has proved to be more popular so far, but this idea has also recently run into trouble, given the current situation with the budget deficit and national debt. Events like the Solyndra bankruptcy have put government clean energy subsidies even more on the defensive. Thus, it seems that neither policies involving money flowing to the government nor policies involving money flowing from the government are politically viable at this point.

One final idea, which does not involve money going to or from government, is simply requiring that cleaner sources provide a certain fraction of our overall power generation. The many state Renewable Portfolio Standards (that do not include nuclear) and the Clean Energy Standard being considered by Congress and the Obama administration (which does include nuclear) are examples of this policy. While better than nothing, such policies are not ideal in that they are crude, and don’t involve a quantitative incentive based on real external costs. An energy source is either defined as “clean,” or it is not. Note that the definition of “clean” would be decided politically, as opposed to objectively based on tangible external costs determined by scientific studies (nuclear’s exclusion from state Renewable Portfolio Standards policies being one outrageous example). Finally, there is the fact that any such policy would require legislation.

All of the above begs the question whether there is a policy available that will encourage the use of cleaner energy sources that is revenue-neutral (i.e., does not involve money flowing to or from the government), does not involve the outright (political) selection of certain energy sources over others, and does not require legislation. Enter the Dispatch Queue

There must be enough power plants in a given region to meet the maximum load (or demand) expected to occur. In fact, total generation capacity must exceed maximum demand by a specified “reserve margin,” to address the possibility of a plant going offline, or other possible considerations. Due to the fact that demand varies significantly with time, a significant fraction of the generation capacity remains offline, some or most of the time. The dispatch queue is a means by which utilities, or independent regional grid operators, decide which power plants will operate in order to meet demand at any given instant. A good discussion of dispatch queues and how they operate can be found in this Department of Energy report.

The general goal of the methodology used to set the dispatch queue order is to minimize overall generation cost, while staying in compliance with all federal or state laws (environmental rules, etc.). This is done by placing the power plants with the lowest “variable” cost first in the queue. Plants with the highest “variable” cost are placed last. The “variable” cost of a plant represents how much more it costs to operate the plant than it costs to leave it idle (i.e., it includes the fuel cost and maintenance costs that arise from operation, but does not include the plant capital cost, personnel costs, or any fixed maintenance costs). Thus, one starts with the least expensive plants, and moves up (in cost) until generation meets demand. The remaining, more expensive plants are not fired up. This ensures that the lowest-operating-cost set of plants is used to meet demand at any given time

As far as who makes the decisions is concerned, in many cases the local utility itself runs the dispatch for its own service territory. In most of the United States, however, there is a large regional grid (covering several utilities) that is operated by an Independent System Operator (ISO) or Regional Transmission Organization (RTO), and those organizations, which are independent of the utilities, set the dispatch queue for the region. The Idea

As discussed above, a plant’s place in the dispatch queue is based upon variable cost, with the lowest variable cost plants being first in the queue. As discussed in the DOE report, all the dispatch queues in the country base the dispatch order almost entirely on variable cost, with the only possible exceptions being issues related to maximizing grid reliability. What if the plant dispatch methodology were revised so that environmental costs were also considered? Ideally, the public health and environmental costs would be objectively and scientifically determined and cast in terms of an equivalent economic cost (as has been done in many scientific studies such as the ExternE study referenced earlier). The calculated external cost would be added to a plant’s variable cost, and its place in the dispatch queue would be adjusted accordingly. The net effect would be that dirtier plants would be run much less often, resulting in greatly reduced pollution.

This could have a huge impact in the United States, especially at the current time. Currently, natural gas prices are so low that the variable costs of combine-cycle natural gas plants are not much higher than those of coal plants, even without considering environmental impacts. Also, there is a large amount of natural gas generation capacity sitting idle.

More specifically, if dispatch queue ordering methods were revised to even place a small (economic) weight on environmental costs, there would be a large switch from coal to gas generation, with coal plants (especially the older, dirtier ones) moving to the back of the dispatch queue, and only running very rarely (at times of very high demand). The specific idea of putting gas plants ahead of coal plants in the dispatch queue is being discussed by others.

The beauty of this idea is that it does not involve any type of tax or government subsidy. It is revenue neutral. Also, depending on the specifics of how it’s implemented, it can be quantitative in nature, with environmental costs of various power plants being objectively weighed, as opposed certain sources simply being chosen, by government/political fiat, over others. It also may not require legislation (see below). Finally, dispatch queues and their policies and methods are a rather arcane subject and are generally below the political radar (many folks haven’t even heard of them). Thus, this approach may allow the nation’s environmental goals to be (quietly) met without causing a political uproar. It could allow policy makers to do the right thing without paying too high of a political cost.

Questions/Issues The DOE report does mention some examples of dispatch queue methods factoring in issues other than just the variable cost. It is fairly common for issues of grid reliability to be considered. Also, compliance with federal or state environmental requirements can have some impacts. Examples of such laws include limits on the hours of operation for certain polluting facilities, or state requirements that a “renewable” facility generate a certain amount of power over the year. The report also discusses the possibility of favoring more fuel efficient gas plants over less efficient ones in the queue, even if using the less efficient plants at that moment would have cost less, in order to save natural gas. Thus, the report does discuss deviations from the pure cost model, to consider things like environmental impact and resource conservation.

I could not ascertain from the DOE report, however, what legal authorities govern the entities that make the plant dispatch decisions (i.e., the ISOs and RTOs), and what types of action would be required in order to change the dispatch methodology (e.g., whether legislation would be required). The DOE report was a study that was called for by the Energy Policy Act of 2005, which implies that its conclusions would be considered in future congressional legislation. I could not tell from reading the report if the lowest cost (only) method of dispatch is actually enshrined somewhere in state or federal law. If so, the changes I’m proposing would require legislation, of course.

The DOE report states that in some regions the local utility runs the dispatch queue itself. In the case of the larger grids run by the ISOs and RTOs (which cover most of the country), the report implies that those entities are heavily influenced, if not governed, by the Federal Energy Regulatory Commission (FERC), which is part of the executive branch of the federal government. In the case of utility-run dispatch queues, it seems that nothing short of new regulations (on pollution limits, or direct guidance on dispatch queue ordering) would result in a change in dispatch policy. Whereas reducing cost and maximizing grid reliability would be directly in the utility’s interest, favoring cleaner generation sources in the queue would not, unless it is driven by regulations. Thus, in this case, legislation would probably be necessary, although it’s conceivable that the EPA could act (like it’s about to on CO2).

In the case of the large grids run by ISOs and RTOs, it’s possible that such a change in dispatch methodology could be made by the federal executive branch, if indeed the FERC has the power to mandate such a change

Effect on Nuclear With respect to the impacts of including environmental costs in plant dispatch order determination, I’ve mainly discussed the effects on gas vs. coal. Indeed, a switch from coal to gas would be the main impact of such a policy change. As for nuclear, as well as renewables, the direct/immediate impact would be minimal. That is because both nuclear and renewable sources have high capital costs but very low variable costs. They also have very low environmental impacts; much lower than those of coal or gas. Thus, they will remain at the front of the dispatch queue, ahead of both coal and gas.

The amount of groundwater into the buildings fluctuates with the rainfall. At the end of September when it rained heavily because of a typhoon, the amount of ground water doubled, and about 7,700 tonnes of water seeped into the buildings in that week.

The groundwater would mix with the contaminated water in the basement of the buildings, and this highly contaminated water is being sent to the water treatment facility. After the density of radioactive materials in the water is lowered and salt removed, the treated water is being used for cooling the reactors.

When the circulatory water injection and cooling system started in late June, there were 127,000 tonnes of contaminated water (highly contaminated water plus the treated water with low contamination). However, as the result of the groundwater inflow, there are now 175,000 tonnes of contaminated water, a 40% increase, as of October 18. None of the water could be released outside the plant.

Concentrated, highly saline waste water after the desalination process is stored in the special tanks. As more water is processed, more tanks are needed. TEPCO is installing 20,000 tonnes storage tanks every month. To secure the space for the tanks the company has been cutting down the trees in the plant compound. There is a system to evaporate water to reduce the amount of waste water, but it is not currently used.

The water level in the turbine buildings where the highly contaminated water after the reactor cooling accumulates is 1 meter below the level at which there is a danger of overflowing. It is not the level that would cause immediate overflow after a heavy rain. However, if the heavy rain is coupled with a trouble at the water treatment system that hampers the water circulation, the water level could rise very rapidly.

The treatment capacity of the water treatment facility is 1,400 tonnes per day. TEPCO emphasizes that the facility is running smoothly and the circulatory water injection system is stable. However, if the current situation continues where groundwater keeps coming into the buildings that needs to be treated, the water treatment facility will be taxed with excess load, which may cause a problem.

It is difficult to stop the inflow of groundwater completely, and TEPCO is not planning any countermeasure construction. Regarding the continued inflow of groundwater into the buildings, TEPCO's Junichi Matsumoto says, "We have to come up with a more compact water treatment system in which we can circulate water without using the basements of the buildings. Otherwise we would be stuck in a situation where we have to treat the groundwater coming into the basements." However, there is no prospect of fundamentally solving the problem.And there will be no such prospect, as TEPCO is now proven to be very good at looking the other way. Over 10 sieverts/hour ultra-hot spot? Not a problem, we will just cordon off the area. What is causing 10 sieverts/hour radiation? Why it's not our problem. How much over 10 sieverts/hour? We don't know because we don't measure such things. High hydrogen concentration in the pipe? Not a problem, we will just blow nitrogen gas. What is causing the high hydrogen concentration? It's not our problem. A worker died after 1 week of work at the plant. Why? It's not our problem, it's the subcontractor's problem...