Group items tagged

"Cleaning," "waiting," and "dismantling" are the three key actions in this process. Needless to say, this all needs to be done while simultaneously containing radioactive materials.

In the case of the Tokai Nuclear Power Plant, the first commercial plant to undergo decommissioning, spent fuel was removed over a span of three years beginning in 1998, and was transported to Britain for reprocessing. Dismantling of the facilities began in 2001, with current efforts being made toward the dismantling of heat exchangers; workers have not yet begun to take the reactor itself apart. The entire process is expected to be an 88.5-billion-yen project involving 563,000 people.

Hitachi Ltd., which manufactures nuclear reactors, says that it "generally takes about 30 years" to decommission a reactor. The Hamaoka Nuclear Power Plant's No. 1 and No. 2 reactors operated by Chubu Electric Power Co. are also expected to take about 30 years before they are decommissioned.

In the case of the Fukushima No. 1 Nuclear Power Plant, meanwhile, the biggest challenge lies in how to remove the fuel, says Tadashi Inoue, a research advisor at the Central Research Institute of Electric Power Industry (CRIEPI), a foundation that conducts research on energy and environmental issues in relation to the electrical power industry.

"we must deal with rubble contaminated with radioactive materials that were scattered in the hydrogen blasts and treat the radiation-tainted water being used to cool nuclear fuel before we can go on to fuel removal."

Currently, the Fukushima plant's operator, Tokyo Electric Power Co. (TEPCO), is desperately trying to treat the contaminated water. Huge challenges remain with regards to the contaminated rubble, as radiation levels of over 10 sieverts per hour were found near outdoor pipes on the plant grounds just the other day. Exposure to such high levels would mean death for most people.

Each step in the process toward decommissioning is complicated and requires great numbers of people. It's a race against time because the maximum amount of radiation that workers can be exposed to is 250 millisieverts.

Prefacing the following as "a personal opinion," Inoue says: "Building a car that can protect the people inside as much as possible from radioactive materials, and attaching an industrial robotic arm to the car that can be manipulated by those people could be one way to go about it."

Two types of fuel removal must take place. One is to take out the spent fuel in the containment pools, and the other is to remove the melted fuel from the reactor cores. Because the radiation levels of the water in the spent fuel pools have not shown any significant changes from before the crisis, it is believed that the spent fuel has not suffered much damage. However, removing it will require repairing and reinstalling cranes to hoist the fuel rods out.

The breached reactor core is a bigger problem. It is believed that raising water levels inside the reactor has been difficult because of a hole in the bottom of the vessel. It will be necessary to plug the hole, and continue filling the vessel with water while extracting the melted fuel. How to fill the vessel with water is still being debated. If the reactor can be filled with water, steps taken after the 1979 Three Mile Island nuclear accident can serve as a guide because in that case, in which approximately 50 percent of the core had melted, workers were able to fill the reactor with water and remove the fuel within.

Inoue predicts that removal of spent fuel from the containment pools will begin about five years after the crisis, and about 10 years in the case of melted fuel from the reactor core. Work on the four reactors at the Fukushima plant will probably take several years.

"Unless we look at the actual reactors and take and analyze fuel samples, we can't know for sure," Inoue adds. Plus, even if workers succeed in removing the fuel, reprocessing it is an even more difficult task. A review of processing methods and storage sites, moreover, has yet to take place.

Meanwhile, at least one expert says he doesn't believe that workers will be able to remove the melted fuel from the crippled plant.

"If there's 10 sieverts per hour of radiation outside, then the levels must be much higher closer to the reactor core," says Tadahiro Katsuta, an associate professor at Meiji University and an expert in reactor engineering and reactor policy who was once a member of an anti-nuclear non-profit organization called Citizens' Nuclear Information Center (CNIC). "The fuel has melted, and we haven't been able to cool it consistently. If work is begun five or 10 years from now when radiation levels have not yet sufficiently gone down, workers' health could be at serious risk."

Katsuta predicts that it will probably take at least 10 years just to determine whether it is possible to remove the fuel. He adds that it could very well take 50 years before the task of dismantling the reactor and other facilities is completed.

What Katsuta has in mind is a Chernobyl-style concrete sarcophagus, which would entail cloaking the melted tomb with massive amounts of concrete. "How could we simultaneously dismantle four reactors that have been contaminated to the extent that they have by radioactive materials?" asks Katsuta. "Japan has little experience in decommissioning reactors, and this case is quite different from standard decommissioning processes. It's not realistic to think we can revert the site back to a vacant lot. I think we should be considering options such as entombing the site with concrete or setting up a protective dome over the damaged reactor buildings

what we face is a great unknown to all of mankind.

SUMMARY OF ESTIMATED CAPITAL AND OTHER COSTS   The estimated capital costs and other costs for decommissioning the nuclear plants, restoring the sites, building out renewables, wind and solar energy balancing plants, and reorganizing electric grids over 9 years are summarized below.    The capital cost and subsidy cost for the increased energy efficiency measures was not estimated, but will likely need to be well over $180 billion over 9 years, or $20 billion/yr, or $20 b/($3286 b in 2010) x 100% = 0.6% of GDP, or $250 per person per yr.     Decommission nuclear plants, restore sites: 23 @ $1 billion/plant = $23 billion Wind turbines, offshore: 53,300 MW @ $4,000,000/MW = $213.2 billion   Wind turbines, onshore: 27,900 MW @ $2,000,000/MW = $55.8 billion Wind feed-in tariff extra costs rolled into electric rates over 9 years: $200 billion  Solar systems: 82,000 MW @ $4,500,000/MW = $369 billion Solar feed-in tariff extra costs rolled into electric rates over 9 years = $250 billion. Wind and solar energy balancing plants: 25,000 MW of CCGTs @ $1,250,000/MW = $31.3 billion Reorganizing European elecric grids tied to German grids: $150 billion

RENEWABLE ENERGY AND ENERGY EFFICIENCY TARGETS   In September 2010 the German government announced the following targets:   Renewable electricity - 35% by 2020 and 80% by 2050 Renewable energy - 18% by 2020, 30% by 2030, and 60% by 2050 Energy efficiency - Reducing the national electricity consumption 50% below 2008 levels by 2050.  http://en.wikipedia.org/wiki/Renewable_energy_in_Germany   Germany has a target to reduce its nation-wide CO2 emissions from all sources by 40% below 1990 levels by 2020 and 80-85% below 1990 levels by 2050. That goal could be achieved, if 100% of electricity is generated by renewables, according to Mr. Flasbarth. Germany is aiming to convince the rest of Europe to follow its lead.

Biomass: At the end of 2010, about 5,200 MW of biomass was installed at a capital cost of about $18 billion. Biomass energy produced was 33.5 TWh, or 5.5% of production. Plans are to add 1,400 MW of biomass plants in future years which, when fully implemented, would produce about 8.6 TWh/yr.   Solar: At the end of 2010, about 17,320 MW of PV solar was installed in Germany at a capital cost of about $100 billion. PV solar energy produced was 12 TWh, or 2% of total production. The excess cost of the feed-in-tariff energy bought by utilities and rolled into the electricity costs of rate payers was about $80 billion during the past 11 years.   Most solar panels are in southern Germany (nation-wide solar CF 0.095). When skies are clear, the solar production peaks at about 7 to 10 GW. Because of insufficient capacity of transmission and quick-ramping gas turbine plants, and because curtailment is not possible, part of the solar energy, produced at a cost to the German economy of about 30 to 50 eurocent/kWh is “sold” at European spot prices of about 5 eurocent/kWh to France which has significant hydro capacity for balancing the variable solar energy. http://theenergycollective.com/willem-post/46142/impact-pv-solar-feed-tariffs-germany  

Wind: At the end of 2010, about 27,200 MW of onshore and offshore wind turbines was installed in Germany at a capital cost of about $50 billion. Wind energy produced was 37.5 TWh, or 6.2% of total production. The excess cost of the feed-in-tariff energy bought by utilities and rolled into electricity costs of rate payers was about $50 billion during the past 11 years.   Most wind turbines are in northern Germany. When wind speeds are higher wind curtailment of 15 to 20 percent takes place because of insufficient transmission capacity and quick-ramping gas turbine plants. The onshore wind costs the Germany economy about 12 eurocent/kWh and the offshore wind about 24 eurocent/kWh. The owners of the wind turbines are compensated for lost production.   The alternative to curtailment is to “sell” the energy at European spot prices of about 5 eurocent/kWh to Norway and Sweden which have significant hydro capacity for balancing the variable wind energy; Denmark has been doing it for about 20 years.   As Germany is very marginal for onshore wind energy (nation-wide onshore wind CF 0.167) and nearly all of the best onshore wind sites have been used up, or are off-limits due to noise/visual/environmental impacts, most of the additional wind energy will have to come from OFFSHORE facilities which produce wind energy at about 2 to 3 times the cost of onshore wind energy. http://theenergycollective.com/willem-post/61774/wind-energy-expensive

A 2009 study by EUtech, engineering consultants, concluded Germany will not achieve its nation-wide CO2 emissions target; the actual reduction will be less than 30%. The head of Germany's Federal Environment Agency (UBA), Jochen Flasbarth, is calling for the government to improve CO2 reduction programs to achieve targets. http://www.spiegel.de/international/germany/0,1518,644677,00.html   GERMAN RENEWABLE ENERGY TO-DATE   Germany announced it had 17% of its electrical energy from renewables in 2010; it was 6.3% in 2000. The sources were 6.2% wind, 5.5% biomass, 3.2% hydro and 2.0% solar. Electricity consumption in 2010 was 603 TWh (production) - 60 TWh (assumed losses) = 543 TWh http://www.volker-quaschning.de/datserv/ren-Strom-D/index_e.php  

Hydro: At the end of 2010, about 4,700 MW of hydro was installed. Hydro energy produced was 19.5 TWh, or 3.2% of production. Hydro growth has been stagnant during the past 20 years. See below website.   As it took about $150 billion of direct investment, plus about $130 billion excess energy cost during the past 11 years to achieve 8.2% of total production from solar and wind energy, and assuming hydro will continue to have little growth, as was the case during the past 20 years (almost all hydro sites have been used up), then nearly all of the renewables growth by 2020 will be mostly from wind, with the remainder from solar and biomass. http://www.renewableenergyworld.com/rea/news/article/2011/03/new-record-for-german-renewable-energy-in-2010??cmpid=WNL-Wednesday-March30-2011   Wind and Solar Energy Depend on Gas: Wind and solar energy is variable and intermittent. This requires quick-ramping gas turbine plants to operate at part-load and quickly ramp up with wind energy ebbs and quickly ramp down with wind energy surges; this happens about 100 to 200 times a day resulting in increased wear and tear. Such operation is very inefficient for gas turbines causing them to use extra fuel/kWh and emit extra CO2/kWh that mostly offset the claimed fuel and CO2 reductions due to wind energy. http://theenergycollective.com/willem-post/64492/wind-energy-reduces-co2-emissions-few-percent  

Wind energy is often sold to the public as making a nation energy independent, but Germany will be buying gas mostly from Russia supplied via the newly constructed pipeline under the Baltic Sea from St. Petersburg to Germany, bypassing Poland.   GERMANY WITHOUT NUCLEAR ENERGY   A study performed by The Breakthrough Institute concluded to achieve the 40% CO2 emissions reduction target and the decommissioning of 21,400 MW of nuclear power plants by 2022, Germany’s electrical energy mix would have to change from 60% fossil, 23% nuclear and 17% renewables in 2010 to 43% fossil and 57% renewables by 2020. This will require a build-out of renewables, reorganization of Europe’s electric grids (Europe’s concurrence will be needed) and acceleration of energy efficiency measures.   According to The Breakthrough Institite, Germany would have to reduce its total electricity consumption by about 22% of current 2020 projections AND achieve its target for 35% electricity generated from renewables by 2020. This would require increased energy efficiency measures to effect an average annual decrease of the electricity consumption/GDP ratio of 3.92% per year, significantly greater than the 1.47% per year decrease assumed by the IEA's BAU forecasts which is based on projected German GDP growth and current German efficiency policies.

The Breakthrough Institute projections are based on electricity consumption of 544  and 532 TWh  in 2008 and 2020, respectively; the corresponding production is 604 TWh in 2008 and 592 TWh in 2020.   http://thebreakthrough.org/blog//2011/06/analysis_germanys_plan_to_phas-print.html http://www.iea.org/textbase/nppdf/free/2007/germany2007.pdf   Build-out of Wind Energy: If it is assumed the current wind to solar energy ratio is maintained at 3 to 1, the wind energy build-out will be 80% offshore and 20% onshore, and the electricity production will be 592 TWh, then the estimated capital cost of the offshore wind turbines will be [{0.57 (all renewables) - 0.11 (assumed biomass + hydro)} x 592 TWh x 3/4] x 0.8 offshore/(8,760 hr/yr x average CF 0.35) = 0.0533 TW offshore wind turbines @ $4 trillion/TW = $213 billion and of the onshore wind turbines will be [{0.57 (all renewables) - 0.11 (assumed biomass + hydro)} x 592 TWh x 3/4] x 0.2 onshore/(8,760 hr/yr x average CF 0.167) = 0.279 TW of wind turbines @ $2 trillion/TW = $56 billion, for a total of $272 billion. The feed in tariff subsidy for 9 years, if maintained similar to existing subsidies to attract adequate capital, will be about $150 billion offshore + $50 billion onshore, for a total of $200 billion.    

Note: The onshore build-out will at least double Germany’s existing onshore wind turbine capacity, plus required transmission systems; i.e., significant niose, environmental and visual impacts over large areas.   Recent studies, based on measured, real-time, 1/4-hour grid operations data sets of the Irish, Colorado and Texas grids, show wind energy does little to reduce CO2 emissions. Such data sets became available during the past 2 to 3 years. Prior studies, based on assumptions, estimates, modeling scenarios, and statistics, etc., significantly overstate CO2 reductions.  http://theenergycollective.com/willem-post/64492/wind-energy-reduces-co2-emissions-few-percent   Build-out of PV Solar Energy: The estimated capital cost of the PV solar capacity will be [{0.57 (all renewables) - 0.11 (assumed biomass + hydro)} x 592 TWh x 1/4]/(8,760 hr/yr x average CF 0.095) = 0.082 TW @ $4.5 trillion/TW = $369 billion. The feed in tariff subsidy, if maintained similar to existing subsidies to attract adequate capital, will be about $250 billion.   Reorganizating Electric Grids: For GW reasons, a self-balancing grid system is needed to minimize CO2 emissions from gas-fired CCGT balancing plants. One way to implement it is to enhance the interconnections of the national grids with European-wide HVDC overlay systems (owning+O&M costs, including transmission losses), and with European-wide selective curtailment of wind energy, and with European-wide demand management and with pumped hydro storage capacity. These measures will reduce, but not eliminate, the need for balancing energy, at greater wind energy penetrations during high-windspeed weather conditions, as frequently occur in Iberia (Spain/Portugal).  

European-wide agreement is needed, the capital cost will be in excess of $150 billion and the adverse impacts on quality of life (noise, visuals, psychological), property values and the environment will be significant over large areas.    Other Capital Costs: The capacity of the quick-ramping CCGT balancing plants was estimated at 25,000 MW; their capital cost is about 25,000 MW x $1,250,000/MW = $31.3 billion. The capital costs of decommissioning and restoring the sites of the 23 nuclear plants will be about $23 billion.   Increased Energy Efficiency: Increased energy efficiency would be more attractive than major build-outs of renewables, because it provides the quickest and biggest "bang for the buck", AND it is invisible, AND it does not make noise, AND it has minimal environmental impact, AND it usually reduces at least 3 times the CO2 per invested dollar, AND it usually creates at least 3 times the jobs per invested dollar, AND it usually creates at least 3 times the energy reduction per invested dollar, AND it does all this without public resistance and controversy.   Rebound, i.e., people going back to old habits of wasting energy, is a concept fostered by the PR of proponents of conspicuous consumption who make money on such consumption. People with little money love their cars getting 35-40 mpg, love getting small electric and heating bills. The rebound is mostly among people who do not care about such bills.

A MORE RATIONAL APPROACH   Global warming is a given for many decades, because the fast-growing large economies of the non-OECD nations will have energy consumption growth far outpacing the energy consumption growth of the slow-growing economies of the OECD nations, no matter what these OECD nations do regarding reducing CO2 emissions of their economies.   It is best to PREPARE for the inevitable additional GW by requiring people to move away from flood-prone areas (unless these areas are effectively protected, as in the Netherlands), requiring new  houses and other buildings to be constructed to a standard such as the Passivhaus standard* (such buildings stay cool in summer and warm in winter and use 80 to 90 percent less energy than standard buildings), and requiring the use of new cars that get at least 50 mpg, and rearranging the world's societies for minimal energy consumption; making them walking/bicycling-friendly would be a good start.   If a nation, such as the US, does not do this, the (owning + O&M) costs of its economy will become so excessive (rising resource prices, increased damage and disruptions from weather events) that its goods and services will become less competitive and an increasing percentage of its population will not be able to afford a decent living standard in such a society.   For example: In the US, the median annual household income (inflation-adjusted) was $49,445, a decline of 7% since 2000. As the world’s population increases to about 10 billion by 2050, a triage-style rationing of resources will become more prevalent. http://www.usatoday.com/news/nation/story/2011-09-13/census-household-income/50383882/1

* A 2-year-old addition to my house is built to near-Passivhaus standards; its heating system consists of a thermostatically-controlled 1 kW electric heater, set at 500 W, that cycles on/off on the coldest days for less than 100 hours/yr. The addition looks inside and out entirely like standard construction. http://theenergycollective.com/willem-post/46652/reducing-energy-use-houses

With over 100,000 man-hours of work having already been conducted by Magnox Ltd and its contractor Erith, the next stage is to demolish the main structure, which is expected to be completed by mid-September. The entire project is set to be completed in November.   Magnox Ltd, which manages the site on behalf of the UK's Nuclear Decommissioning Authority (NDA), said that demolition "marks a significant milestone towards reaching care and maintenance on the site, which will see it placed into passive storage in 2015."

The 'care and maintenance' stage of decommissioning is when the reactor buildings are placed in a passive state, known as Safestore, and are monitored and maintained until the site is completely cleared in about 65 years' time, by which time the residual radioactivity will have decreased significantly.

Brian Burnett, head of the Magnox program at the NDA, said, "Accelerating care and maintenance, whilst challenging, is an important element of delivering improved value for money." He added, "The demolition of the turbine hall at Bradwell is a significant decommissioning milestone."

Freeze and thaw   Meanwhile, the Bradwell site has become the first in the UK to use a 'freeze dredging' process, developed in conjunction with FriGeo of Sweden, to remove sludge from the site's used fuel storage pool. The process works by freezing small amounts of waste whilst the equipment is submerged in the pond water. The frozen mass is then thawed to separate out the sludge and debris. The process of thawing and dewatering reduces the moisture content of the contaminated materials, thereby minimizing waste volumes.

The system allows the team operating the machinery to work remotely from the pool area, with the help of cameras and hoists, resulting in a much lower radiological hazard working environment.   Magnox said that the first drum of captured waste had successfully been filled in late July. Up to a further 60 drums are expected to be filled by the end of October

The FriGeo method of freeze dredging has previously been used to remove oil-polluted sludge from the bottom of bodies of water.

The key part of the decommissioning work is to remove a total of 1,496 fuel rods from the No. 1 to 3 nuclear reactors and 3,108 fuel rods from nuclear fuel pools of the No. 1 to 4 reactors. The government and TEPCO are expected to start decommissioning the reactors early in the New Year after unveiling detailed plans around Dec. 16 that the nuclear plant has been brought under control by achieving a stable state called a ''cold shutdown.''

TEPCO said it would bring the nuclear plant under control by filling the reactors with water. But subsequent analysis of the accident suggested that the No. 1 and 2 reactors had holes of up to 50 square centimeters caused by hydrogen explosions and the like. In the work schedule announced in May, TEPCO said it had scrapped its plan to repair the containment vessels and suspended the work to fill them with water.

workers have been fighting an uphill battle to remove crumbled fuel. The reactors had been running without cooling water for a long time, and most of the fuel melted and apparently dropped into the containment vessel from the bottom of the pressure vessel at the No. 1 reactor

A single fuel rod contains about 170 kilograms of uranium, and a simple calculation suggests that about 254 tons of uranium in the reactors alone must be recovered. The distance between the upper lid and the bottom of a containment vessel is up to 35 meters. From that far away, the work has to be done to chop off and recover melted and crumbled fuel by using remote controlled cranes. Furthermore, the melted fuel is mixed with metal from fuel pellets and reactor parts.

"Because no one has seen the inside of the nuclear reactors, the timing of starting the work to recover nuclear fuel mentioned in the report is only a nonbinding target."

The 84,877 fuel elements in the reactors were removed between 1989 and 1992, which resulted in 99% of the radioactivity being taken from the site.

Under current plans, the operation to remove the fuel from both units should be completed in 2013. After most of the structures at Oldbury have been removed, the site will enter the 'care and maintenance' stage of decommissioning around 2027, after which the reactor is left to cool. Final site clearance activities are scheduled between 2092 and 2101.   The last two remaining Magnox reactors currently in operation in the UK are at Wylfa site. The two 490 MWe units there are scheduled to shut down at the end of 2012.   Horizon Nuclear Power - a 50-50 joint venture between RWE nPower and EOn UK - plans to submit a planning application for a new nuclear power plant at Oldbury around 2014. According to the company, "Given the right market conditions, and subject to a final investment decision, preliminary works could begin in 2016, followed by main construction from 2019." Horizon is yet to decide which of the two available reactor designs - Areva's EPR or Westinghouse's AP1000 - it would like to build.

Since Japan, a key U.S. ally, had already started its own nuclear power generation program, Washington did not hesitate to seek Tokyo's backing for its request. It was apparent that the United States constructed nuclear reactors without having decided on disposal methods, forcing it to consider dumping them at sea after they were decommissioned.

Japan did not offer a clear answer when it was approached by the United States on the issue. Eventually, however, Washington succeeded in incorporating the clause into the treaty. In 1972, the United States was already dismantling early-stage nuclear reactors that had been used for testing. However, the disposal method of large-scale nuclear reactors for commercial purposes had not been decided although it was an issue that could not be shelved indefinitely.

The official noted that any attempt to bury the reactors on land would invite a public backlash. He also pointed to the financial difficulty of scientifically processing the reactors until the risk of radioactive contamination was totally eliminated. Then, the official said the only other option was to dump them at sea, and asked Japan for cooperation.

According to Kumao Kaneko, now aged 74 and then a member of the Foreign Ministry team involved in the negotiations, Japan did not take specific steps to assist the United States in this delicate matter. Eventually, during the general meeting of countries for the London Convention, the United States proposed incorporating a clause that would enable it to dump nuclear reactors at sea in exceptional cases in which all other means of disposal presented a risk to human health.

When presenting the proposal, the United States made no mention of its intention to dump its nuclear reactors at sea far into the future. The proposal was accepted. In the early 1970s, sea pollution was a huge international issue. Against that backdrop, countries worked feverishly to put the finishing touches on the London Convention. The treaty designated high-level radioactive substances as well as other materials, including mercury and cadmium, as waste whose dumping at sea is prohibited.

In 1993 revisions to the London Convention, the dumping of radioactive waste at sea was totally prohibited. However, the clause that approved of dumping in exceptional cases remained. For this reason, under the London Convention, it is possible for member countries of the treaty to dump radioactive waste at sea if they obtain the OK from the other parties as well as the International Atomic Energy Agency. According to the IAEA, the United States has not dumped radioactive waste at sea since 1970. Instead, it buries decommissioned nuclear reactors underground.

If Fukushima happened in the US? The people would pay the bill.

Closure could also slow the decommissioning of other nuclear reactors in Britain. Revenue from Thorp was expected to provide much of the £70bn conservatively estimated to be needed to decommission Britain's reactors and clean up the environment after 50 years of nuclear power. Most first-generation UK reactors are expected to have closed within 10 years.

To date, Thorp has completed about 6,000 tonnes of its initial order book and is now, largely as a result of the broken evaporators, limited to processing 200 tonnes a year – about a sixth of its original design capacity.