Nuclear power plants in Japan don't become Global warming measures

1. Life cycle CO2 emissions per kWh of Nuclear Power Generation

(1) Evaluation by Central Research Institute of Electric Power Industry (CRIEPI), Japan

Measures for global warming are used for the excuse for promotion of nuclear power. For example, In the Webpage entitled "Nuclear power make low carbon society", Kansai Electric Power Company shows a graph of CO2 emission according to various power supplies, LC-CO2 emissions per kWh are coal 975ｇ, oil 742g, solar PV 53g, wind power 29g, nuclear 25g. Company appeals that the emission of nuclear is less than that of solar PV or wind power.

I visited last year the Low Carbon Expo held in Banciao City, Taipei, Taiwan. I was surprised that Taipower exhibited the panel that shows same emissions. If the country is different and the condition is different, emissions are different, but the PR was a copy.

The source of the PR is a report of The Central Research Institute of Electric Power Industry(CRIEPI) managed by investment of electric power company, published in 2001.The report says the LC-CO2 emission per kWh of nuclear power plant. The evaluation is done under the condition of nuclear fuel cycle including reprocessing in Japan, MOX fuels fabrication, MOX fuels one time use, HLW storage and HLW disposal. But the condition has not been achieved in Japan.
Meanwhile, the evaluation of solar PV and wind power is done under the condition of an average technology at the time of 1996. CRIEPI report says emission of solar PV has the possibility of becoming half, and wind power becoming 70 ％, by the production expansion. One is a value when the future, and a past other value. Is it impartial?

I think CRIEPI report has a lot of other problems. The evaluation of nuclear is done by assumption of which the loss doesn't go out in each process such as Uranium mining, refinement, conversion, concentrate, re-conversion, molding, reprocessing. This assumption is a desk theory. The calculation includes HLW disposal, but there is no energy consumption after the HLW disposal site is closed. EPA(USA) says that the restriction of one million years for HLW is necessary. Even if HLW disposal site is closed, monitoring is not necessary? CO2 emission 0 is impossible. Because of the HLW disposal site is not decided somewhere, Transportation to the disposal site is not included in the calculation.
CRIEPI report says because the evaluation changes greatly depending on the precondition, you should interpret the result after understanding enough the influence that the change in the precondition gives the result.
CRIEPI updated the evaluation based on data in fiscal year 2009, published in July this year. LC-CO2 emissions per kWh are coal 943ｇ, oil 738g, solar PV 38g, wind power 25g, nuclear 20g. These figures will be used for PR in the future.

(2) In research results of the world

According to Professor Kenichi Oshima at Ritsumeikan University, Prof. Sovacool reviewed 103 researches published in English that estimates greenhouse emission from nuclear power plant. He excluded the researches that passed ten years and the research based on unpublished data, the researches that fill the same standard is 19. According to 19 researches, LC-CO2 emissions per kWh of nuclear is 1.36g or more, 288.25g or less, and 66g on average. He was pointing it out that the evaluation changes which range of the nuclear fuel cycle included, and depend on method of uranium enrichment with large amount of energy use, type of reactor.

After all, the emission of the nuclear is smaller than the emission of thermal power generation, but larger than the emission of solar PV and wind power.

2. Realities of CO2 exhaust from nuclear power plant in Japan

To examine the results value of Japan, I claimed indicating, and analyzed the greenhouse emission in 2006 〜 2008, based on Global warming measures promotion law. Nuclear power plant that the amount of the energy use is over crude oil conversion 1500kl/year: as shown in the Table2.

P:PWR　B:BWR

Kashiwazaki Kariwa nuclear power plant was struck by the Chuetsuoki earthquake in 2007. The plant exhausted sulfur hexafluoride enclosed with the transformer. The plant had stopped completely in 2008, but the plant has exhausted a large amount of CO2 because of the restoration construction. The Shiga nuclear power plant also had stopped completely in 2007, it was the largest amount of the exhaust in this year.

It is a lie that Nuclear power plant doesn't exhaust CO2 when electricity is generated.

Table2 is shown by "Indirect exhaust" method. The amount of the CO2 exhaust when electricity is generated from the power plant is distributed to the final consumption section. "Before allocation" shows amounts actually exhausted from power plants. There are actual exhausts from most BWR. Those are from auxiliary boilers those are the main equipment. For BWR, to prevent radioactive steam leak, steam generated by auxiliary boilers seal the space between turbine axle and casing when nuclear reactor is started and stop. The fuel of auxiliary boiler is a crude petroleum or electricity. The auxiliary boilers always move to use it also for heating buildings, waste management facilities, and outdoor tanks etc. The auxiliary boilers of Fukushima�U are all electricity, there is no data from Fukushima�U. Most BWR always burn the crude petroleum as a fuel of auxiliary boilers and have exhausted CO2.

PWR mainly exhausts CO2 by the energy use for periodic overhaul. PWR of the table2 have multiple reactors, so I show the relation of the average availability of multiple reactors and amount of the CO2 exhaust in Figure1. For BWR, auxiliary boilers exhaust doesn't relate to availability, so I show the relation of the value subtracted auxiliary boiler exhaust from gross discharge and availability rates in Figure2. You can see the amount of the exhaust increases when availability rates falls. Because of the availability rates of the nuclear power plant in Japan are 60% level recently, a large amount of exhaust is expected.

In the data disclosed this time, the data such as Rokkasyo reprocessing plant is included. The amount of the exhaust by the reprocess trial run is a large value. There are constant exhaust from decommissioning "Fugen" and fast breeder reactor "Monju". The exhaust from the process of the nuclear fuel cycle that has not been established yet and the research and development are also large. The amount of CO2 exhausted from the entire nuclear power cannot be disregarded.

Nuclear power plant cannot do the output adjustment and become only the power supply of the base loading. It is said that if one nuclear power plant is increased, 2 or 3 thermal power plants are necessary, because nuclear power plants have the crisis of the stop together by an accident and a scandal. After all, it is expected that the thermal power plant is increased with the nuclear power plant, and the exhaust of CO2 increases. To achieve the low carbon society, the reduction in a total energy consumption is indispensable. Promotion of nuclear power only extends the energy waste structure.

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This report written in September 2010 for NO NUKES ASIA FORUM held in Taiwan

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