Results of Survey of Status of Storage of Nuclear Materials
February 27, 2012
Chubu Electric Power Co.,Inc.
Based on instructions received from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) on August 08, 2011(Note1), Chubu Electric Power Co., Inc. has conducted a survey to determine whether the company is storing nuclear materials(Note2) without the accountancy and control(Note3) demanded by law. During the course of this survey seven substances were discovered on the grounds of the Hamaoka Nuclear Power Station that possibly contained nuclear materials. Measurement of the quantities of nuclear materials and other studies demonstrated on December 21, 2011 that these were in fact nuclear materials, and this finding was reported verbally to MEXT on the same day.
Also on the same day, MEXT instructed Chubu Electric Power to submit a report(Note4) by December 22, 2011 concerning the nuclear materials discovered up to that point for which the accountancy and control procedures demanded by law were not being conducted. Chubu Electric Power therefore submitted a report to MEXT concerning the four nuclear materials of the seven discovered for which accountancy and control was legally required.(Reported December 22, 2011)
Upon submission of the report to MEXT on December 22, 2011, Chubu Electric Power was verbally instructed to conduct a detailed survey. The results of this detailed survey indicated that procedures demanded by the Nuclear Reactor Regulation Law had not been conducted in the case of eight nuclear materials. Five of these materials were the subject of the report submitted on the basis of the instructions received from MEXT on August 08, 2011.
The results of the detailed survey were reported to MEXT today.
1. Scope of survey
Buildings, storage racks, office desks and cabinets and other areas were surveyed in workplaces that might handle nuclear materials or simulated nuclear materials.
(1) Hamaoka Nuclear Power Station : (Total) Approximately 20,000 places
(2)Head Office and branches : (Total) Approximately 2,600 places
2. Survey method
Inspections were conducted visually and using radiation measurement devices by employees of Chubu Electric Power or individuals contracted for this purpose by Chubu Electric Power.
3. Survey results
(1) Nuclear materials discovered
The survey discovered 47 instances of nuclear materials being stored without accountancy and control. Of these, eight instances were materials for which permission must be obtained for use under the Nuclear Reactor Regulation Law. The materials in five of these eight instances were the subject of a report submitted on the basis of instructions received from MEXT on August 08, 2011 (nuclear materials subject to accountancy and control). The results of the survey were reported to MEXT today.
a. Nuclear materials for which permission must be obtained for use under the Nuclear Reactor Regulation Law (Eight instances)
Hamaoka Nuclear Power Station
1 Model of fuel for high-temperature gas-cooled reactor (Trace amounts of thorium adhering) (Fuel modeled using aluminum oxide)
Discovered since December 22, 2011
2 Pellets (Natural uranium)
Announced December 22, 2011
3 Panel consisting of metal sheet coated with nuclear material (depleted uranium)
4 Yellowcake (Natural uranium)
The surface radiation levels of these nuclear materials ranged between 0.1 μSv/h and 8.5 μSv/h. All of the materials were stored in locked boxes in the radiation-controlled area of Hamaoka Nuclear Power Station, and therefore presented no risk to human health.
Because the five materials listed in 1 to 3 above are internationally controlled materials according to the terms of the agreement with the International Atomic Energy Agency (IAEA), in addition to being materials subject to reporting based on instructions from MEXT (nuclear materials subject to accountancy and control), they are also materials for which permission must be obtained for use under the Nuclear Reactor Regulation Law.
The three materials in 4 are not internationally controlled materials, and therefore it is not necessary to obtain permission for their use under the Nuclear Reactor Regulation Law.
b. Nuclear materials for which no procedures are required under the Nuclear Reactor Regulation Law (39 instances)
Thirty-nine instances of storage of uranium ores and similar materials were determined by the survey. Because the level of radioactivity of these materials and the quantities of uranium and thorium they contained fell below the levels for which notification is mandatory under the Nuclear Reactor Regulation Law, no procedures are required by law in relation to the materials.
The materials are believed to have been used as exhibits and display items for public relations purposes.
(3)Period and channels of acquisition
Staff members involved at the time were queried regarding the period of acquisition of the eight materials requiring permission for use under the Nuclear Reactor Regulation Law and the channels by which they were obtained, and it is believed on this basis that they were obtained to serve as display items for public relations purposes in the mid-1970s.
With regard to the channels of acquisition of the materials, labels on the containers and other information suggest that four materials (the model of fuel for a high-temperature gas-cooled reactor in 1 and the yellowcake samples in 4) were obtained from overseas mining companies. The channels for acquisition of the other four materials (the pellets in 2 and the panel consisting of a metal sheet coated with nuclear material in 3) could not be verified.
4. Future responses
(1) Measures to prevent reoccurrence
Chubu Electric has conducted the procedures demanded by the Nuclear Reactor Regulation Law in relation to nuclear fuels and other materials actually employed in nuclear reactors, but the procedures demanded by the law have not been conducted in the case of the samples and exhibits for public relations purposes, etc. discovered in this inspection. This is believed to be due to a lack of knowledge regarding the law in departments other than those directly handling nuclear materials. The following measures will therefore be put in place in future.
a. Education concerning the handling of nuclear materials
We will provide education concerning the Nuclear Reactor Regulation Law for employees of all departments that might handle nuclear materials or models of nuclear materials.
b. Establishment of section responsible for centralized inventory management of nuclear materials not directly used in nuclear power generation
We will establish a section responsible for centralized inventory management of nuclear materials throughout the company that are not directly used in nuclear power generation. We will also employ a system in which that section conducts checks when models or simulated nuclear materials are obtained.
(2) Management of nuclear materials revealed by the survey
In the case of the eight instances of nuclear materials for which permission must be obtained for use under the Nuclear Reactor Regulation Law, the procedures required by law will be conducted, and the materials will be managed by the relevant department.
(Note1) Chubu Electric Power received the "Request to Study Nuclear Materials Not under Accountancy and Control" (2011 Research and Development Policy Division, Research and Development Bureau No. 71) from MEXT on August 08, 2011.
(Note2) Accountancy and control refers to strict and accurate control of inventory quantities of internationally controlled materials such as uranium fuel used in nuclear power stations. Accountancy and control is required by law.
(Note3) Nuclear substances requiring accountancy and control are nuclear fuel materials classified as internationally controlled materials on the basis of an agreement with the International Atomic Energy Agency (IAEA).
(Note4) Chubu Electric Power received "Concerning Reporting on Nuclear Fuel Materials Not under Accountancy and Control as Based on the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors (Request)" (2011 Research and Development Policy Division, Research and Development Bureau No. 133) from MEXT on December 21, 2011.