from NUKE INFO TOKYO 65 (May./Jun. 1998)
-- Cover-up on Loss of Radioactive Metal Fragments Revealed
-- Preliminary Calculations for Clearance Levels Presented
-- AEC Drafts Report on Int'l Coop.
-- Summary of Long-term "Outlook" Released
Cover-up on Loss of Radioactive Metal Fragments Revealed
Careless management of radioactive substances has once again shocked the Japanese public. On April 7, an anonymous letter delivered to the Science and Technology Agency (STA) revealed the usual cover-up ploy played by the nuclear industry. According to the letter, back in 1995, 24 metal fragments that had been irradiated at Tokyo Electric Power Co.'s (TEPCO) Kashiwazaki-Kariwa 5 reactor in Niigata Prefecture were sent to Nippon Nuclear Fuel Development Co., Ltd. (jointly owned by Hitachi and Toshiba) in Oarai, Ibaraki Prefecture to test the effect of radiation on the strength of metals.
Although it is required by regulation that these test pieces be stored in a storage pool after any testing, they were left in the laboratory until December 1997 when someone noticed that 19 of them were missing. Secret investigations were being conducted when finally someone decided to notify the STA.
After receiving the letter, STA conducted investigations at the firm and confirmed that the allegations were true. Ibaraki Prefectural Police Headquarters searched the company on the charge that the company failed to report an accident, an obligation stipulated in the Law concerning Prevention from Radiation Hazards Due to Radio-Isotopes, etc.
Later on March 20, Japanese media reported that all of the missing fragments were found inside a tightly sealed, high-level waste container stored at the firm's facility. The firm will continue investigating exactly how these fragments reached the container without any reports. The Prefectural Police have also decided to send papers to the Public Prosecutor's Office. The case has shown the firm's lax control measures on the management of radioactive substances.
Preliminary Calculations for Clearance Levels Presented
Preliminary calculations have recently been presented by the Government to be used for the so-called "clearance levels" which divide radioactive wastes into two groups: those considered as "radioactive" and those considered as "ordinary (nonradioactive) waste". The figures and the basic calculations were presented on April 24 at a meeting of Nuclear Safety Commission's sub-committee on radioactive waste safety standards. Calculations were made by a working group that reported to the sub-committee. Final approval of these figures will be made sometime within this year, after being examined by the sub-committee and opinions from the public are received.
The clearance levels for concentrations of radionuclides in the waste will be set so that the public expo-sure is limited to 10 micro Sv or less. Radioactive concentrations for each nuclide were calculated in order to keep the exposure level due to underground disposal or recycling below the same limit. Calculations were made by positing various potential exposure routes.
The report explains that as a result of the calculations, the clearance levels of iodine-129, chlorine-36, technetium-99 and tritium have been lowered by two orders of magnitude than those suggested by IAEA. On the other hand, those of manganese-54 and zinc-65 were raised by factor 10. It is explained that the difference from the IAEA levels was caused because calculations "were based on the food intake data of Japanese people." Still, the fact that a difference can become as large as orders of magnitudes just by changing parameters poses a question regarding the validity of such calculations.
AEC Drafts Report on Int'l Coop.
On April 27 the Atomic Energy Commission's (AEC) sub-committee on international nuclear power co-operation drafted a final report on ideal methods and measures for co-operation. The report will be approved after collecting and incorporating opinions from the public. However, no significant changes in the report can be expected.
The report suggests various measures in two geographical areas; Region 1: the neighbouring Asian region; and Region 2: countries of the former Soviet Union, and Middle and Eastern Europe. For the countries and regions included in Area 1, the Report states that co-operation will be made according to levels of nuclear development. The point that co-operation should take place on the securing of safety is also referred to in discussions regarding Region 2.
The biggest problem in measures suggested for Region 2 is the disposal of plutonium produced from dismantled nuclear warheads, where technological assistance for use of plutonium in MOX is specifically suggested in the report. Though the authors boast about the "contribution for nuclear arms reduction," Japan's involvement in disposition of military plutonium would conflict with the fact that the nation's nuclear development is legally limited to "peaceful uses." Similar conclusions can be drawn regarding the fact that the report proposes a joint study with Russia and Ukraine concerning fast breeder reactors.
Summary of Long-term "Outlook" Released
Gist of the new "Outlook for Long-Term Energy Supply and Demand" was released on May 11 at a meeting of the Supply and Demand Sub-committee which comes under Ministry of International Trade and Industry's (MITI) Advisory Committee for Energy. The last issue of the "Outlook" currently being reviewed was issued in June 1996. The Outlook has been the basis of Japan's energy policies of all kinds.
The recent review had been conducted in response to the set up of target reduction rate of 6% (as compared to the 1990 figure) of CO2 and other greenhouse effect gas to be achieved between 2008 and 2010. Such targets are required in the Protocol adopted by the 3rd Conference of the Parties to the United Nation's Framework Convention on Climate Change (COP3) held in December last year in Kyoto.
According to the new Outlook, the amount of electricity generated in fiscal year (FY) 2010 by general electric power companies will be 1.06 million GWh, 43% up from FY1990 and 20% up from FY1996. In terms of actual power sources, dependency on petroleum will be reduced by a shift to natural gas. However, the ban on the new construction of petroleum thermal power plants will be lifted, while the share of cheap coal will increase. For new energy sources, waste power generation will be mainly promoted, and generation by photovoltaics, solar thermal and wind power are expected to increase slightly.
It is obvious from this Outlook that the emission of CO2 will increase. What the Government expects to do in order to achieve the reduction goals is to promote even further nuclear power, which is considered ?clean? in terms of CO2 emission. The Outlook states that if construction of 20 more nuclear plants under the current target cannot be achieved, the facility usage rate will be raised to 83%. A Mid-term report is expected in the middle of June.