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Montreal, Canada

Atomic Energy of Canada Limited is a Canadian federal Crown corporation and Canada's largest nuclear science and technology laboratory. AECL developed the CANDU reactor technology starting in the 1950s, and in October 2011 licensed this technology to Candu Energy .Today AECL develops peaceful and innovative applications from nuclear technology through expertise in physics, metallurgy, chemistry, biology and engineering. AECL's activities range from research and development, design and engineering to specialized technology development, waste management and decommissioning. AECL partners with Canadian universities, other Canadian government and private-sector R&D agencies , various national laboratories outside Canada, and international agencies such as the IAEA.AECL describes its goal as ensuring that "Canadians and the world receive energy, health, environmental and economic benefits from nuclear science and technology - with confidence that nuclear safety and security are assured".Until October 2011 AECL was also the vendor of CANDU technology, which it had exported worldwide. Throughout the 1960s-2000s AECL marketed and built CANDU facilities in India, South Korea, Argentina, Romania, and the People's Republic of China. It is a member of the World Nuclear Association trade group.In addition, AECL manufactures nuclear medicine radioisotopes for supply to MDS Nordion in Ottawa, Ontario, and is the world's largest supplier of Molybdenum-99 for diagnostic tests, and Cobalt-60 for cancer therapy.AECL is funded through a combination of federal government appropriations and commercial revenue. In 2009, AECL received $651 million in federal support.In October 2011 the federal government of Canada sold the commercial CANDU design and marketing business of AECL to Candu Energy for $15 million . The sale entered the exclusive negotiation stage in February, a month after the other bidder, Bruce Power pulled out). Poor sales and cost overruns were reasons for the divestment though SNC-Lavalin expects to reverse that trend by focusing on new generation reactors. SNC-Lavalin Nuclear Inc, SNC's nuclear subsidiary is already part of Team CANDU, a group of five companies that manufacture and refurbish the CANDU reactors. The government will continue to own the Chalk River Laboratories . The transaction puts 800 jobs at risk while improving job security for 1,200 employees. Due to safety concerns many countries are considering thorium nuclear reactors which AECL's CANDU reactors easily convert into . Higher energy yields using thorium as the fuel also makes it more attractive. OMERS has also shown interest in the company. Wikipedia.


The Canadian deep geological repository (DGR) concept involves placement of used fuel containers (UFC's) at a depth of 500-1000 m in a stable rock mass, surrounded by compacted bentonite-based barriers that fulfill multiple specific roles including hydraulic, mechanical, thermal, and chemical protection of UFC's and control of radionuclide migration. Microbial characteristics of bentonite-based buffer materials used in a number of large-scale experiments in AECL's Underground Research Laboratory (URL) were studied in order to address the potential for microbial activity and its possible consequences in a DGR. Buffer and sealing materials consisted of 50 to 70% bentonite with the remainder silica sand. Backfill materials consisted of 25% clay and 75% crushed, graded rock or 10% bentonite and 90% sand. Microbial analysis included bulk buffer and backfills samples as well as samples taken from interface environments. Results showed that culturable populations of heterotrophic aerobes, anaerobes and sulphate-reducing bacteria (SRB) were present at all locations examined, more abundant at interface locations, and absent only in those samples affected by heat and desiccation. Compaction upon placement reduced the culturable aerobic population by several orders of magnitude but culturable anaerobic microbes were not significantly affected by compaction. The viable population was considerably larger than the culturable population, suggesting potential for future increased activity, if conditions became more favourable. The buffer materials studied here appear not able to reduce microbial activity sufficiently to the point of being insignificant with respect to possible consequences in a DGR. Therefore, the current Canadian DGR design now employs compacted 100% bentonite buffer directly in contact with UFC's, in order to attempt to reduce microbial activity in this barrier to insignificant levels. © 2008 Elsevier B.V. All rights reserved. Source


Data on the concentration of radionuclides in air for March following the reactor failures at the Fukushima NPP were available for Takasaki, Chiba and Tokyo. Gamma dose data for the same/close locations and for fixed locations in other prefectures were also obtained. Gamma dose data was used to calculate the cumulative gamma dose, during 2 weeks (15th-28th March) following the power plant failures. Corresponding doses were calculated for sites in other Japanese prefectures - except Fukushima Prefecture, for which equivalent monitoring data was not published. For Takasaki, Chiba and Tokyo air concentration data and ICRP dose coefficients were used to calculate inhalation committed effective doses (CED, E50) and thyroid equivalent doses (H) for adult members of the public. Average ratios of gamma dose to inhalation CED and inhalation CED from iodine isotopes to thyroid equivalent dose, determined for Takasaki, Chiba and Tokyo, were then used to predict these quantities for sites in other prefectures. Cumulative gamma dose profiles were used to identify dose increments that could be attributed to Fukushima releases within 11 prefectures (excluding Fukushima Prefecture). The most impacted of these were located in Gunma, Ibaraki, Tochigi and Saitama Prefectures - to the south of Fukushima - and in Miyagi Prefecture - to the north of Fukushima. Calculated total doses ranged from 16 μSv in Shizuoka (Shizuoka) to 400 μSv in Ibaraki (Mito). The total doses calculated for the major population centres of Tokyo and Chiba were 97 μSv and 80 μSv, respectively. For all prefecture locations the largest calculated contribution to total dose, during the period of assessment, was from inhalation (~80%). Estimated thyroid equivalent doses ranged from 5.9 mSv in Ibaraki to 200 μSv in Shizuoka. All total doses calculated were probably overestimates - since no allowances were made for shielding and shelter during the passage of radioactive clouds. Minor contributions to dose from the ingestion of contaminated food and water were not calculated. © 2012. Source


Patent
Atomic Energy of Canada | Date: 2015-08-14

The present invention provides an apparatus for detecting and/or repositioning annulus spacers used to maintain the position of a pressure tube within a calandria tube of a nuclear reactor. The method comprises the steps of: vibrationally isolating a section of the pressure tube; vibrating the wall of said pressure tube within said isolated section; detecting vibration of the wall at a minimum of two axial positions within said isolated sections; and detecting the reduction in vibration level of the wall at one or more of said axial positions in comparison to the remaining axial positions. The apparatus comprises a tool head to be inserted into the pressure tube, the tool head comprising a first end and a second and a clamping block m each of said ends. The clamping blocks are used to vibrationally isolate a section of the pressure tube located between said ends. The apparatus also comprises piezo-actuators operable to vibrate said pressure tube; and accelerometers used for measuring vibration of said pressure tube.


Patent
Atomic Energy of Canada | Date: 2014-03-28

A tool may be inserted into the pressure tube inside a calandria tube of a fuel channel of a nuclear reactor. Once in position, the tool may act to generate information useful for determining a location for an annulus spacer. Once the annulus spacer has been located, the tool may act to generate information useful for determining a compressive load on the annulus spacer due to the annulus spacer being pinched between the two tubes. In both the locating and the load determining, the tool may act to isolate a section of the pressure tube, excite the isolated section of the pressure tube with vibrations and measure resultant tube vibrations. Tube vibration characteristics, determined from the vibrations, may then be analyzed to determine an axial location along the pressure tube for the annulus spacer and/or determine a load on the annulus spacer.


Patent
Atomic Energy of Canada | Date: 2014-03-19

A system for determining a radiation dose in real time can include at least one three-dimensional target object to be exposed to ionizing radiation. The at least one target object may include a scintillating gel material. The scintillating gel material may emit light when exposed to the ionizing radiation. An imaging system may be configured to capture at least a first image of the target object from a first position, and a second image of the target object from a second position relative to the target object. A controller may be connected to the imaging system and may be configured to the process the first and second images to provide a three-dimensional dose distribution in real-time.

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