[en] The low pressure emergency core injection (ECI) system at Bruce NGS 'A' is being replaced by a new high pressure system. The new system is similar to that being installed in the Bruce NGS 'B' plant which is scheduled to start up later this year. The new system at Bruce NGS 'A' will be connected to Unit 4 in April 1984, and the other units will be converted at six monthly intervals. Commissioning activities are well under way and it is apparent that there are significant differences between commissioning a major retro fit in an existing station, compared with commissioning a whole new project

[en] CANDU reactor fuel channels are connected to the primary heat transport system by mechanical joints known as feeder couplings. In 1991, three feeder coupling leakages were discovered in Bruce 4. These leakages required the unit to be shut down for repair. An investigation showed that the leakage was caused by a small 'separation' at the couplings. The assessment was that this was unlikely to be a generic issue, because the later reactors have stronger capscrews. At the time of the conference, further improvements were being considered for the seal ring and capscrew materials, and more accurate capscrew preload measurements. 3 tabs., 10 figs

[en] When reactor 4 at Canada's Bruce A nuclear power station was shut down because of a coolant blockage in one of the fuel channels, a special ''submarine'' was developed but failed to remove the obstruction. So a tractor was tried instead and proved to be more successful. The problem and eventual solution is discussed. (U.K.)

[en] Procedure is described of detecting a foreign body in the BRUCE power reactor cooling system pipeline and removing it. The design is considered of a device used for cleaning the reactor distributing manifold

[en] The first two units of the 3.2 GW Bruce A 1.75 billion dollar generating station are already supplying power, and the last two units will start up in 1978 and 1979 respectively. Bruce B, now scheduled to start up between 1983 and 1986, will cost 4 billion. The fuel-handling and safety arrangements differ in many respects from those at Pickering. The four 800 MW units are laid out in line with two units on each side of a central control and service area, with only two pairs of fuelling machines for the four reactors. Cylindrical reactor buildings have been eliminated. Other major differences compared with Pickering are the use of a water-filled biological shield and the elimination of the moderator dump system. These and other improvements in design are discussed. (N.D.H.)

[en] Short communication; 1 ref.; and, 1 figure

[en] This report presents AECB project staff's review of major licensing issues and of the operational performance of the station during 1987. Ontario Hydro reports and official correspondence and observations on AECB staff at site have been taken into consideration. The report is limited to aspects of the station performance that AECB staff considers to have a safety significance. Where significant developments associated with issues addressed in the report occurred in the early part of 1988 (up to the time of writing), these are mentioned where appropriate. Ontario Hydro's Quarterly Reports for 1987 contain detailed technical information on the performance of the station, individual units and unit systems. It is the opinion of AECB project staff that despite a number of commendable actions and achievements which are identified in this report, the performance of the station in 1987 was only marginally satisfactory and less satisfactory than in 1986. This assessment is supported by key performance indicators such as the number of reportable significant events, the number of events caused by or influenced by human error and the reactor trip frequency, all of which exceeded 1986 levels, and also by the lack of satisfactory progress made during the year on actions to address the findings of the Fall '86 AECB Assessment of Operating Practices. AECB staff considers that the outstanding operations and maintenance problems that were identified in the 1986 Assessment are due, in part, to an ineffective quality assurance program, and in part to a shortage of resources

[en] Bruce A Nuclear Division (BAND) units are operating at ∼ 75% of full power, because of the potential of a power pulse in the event of an inlet header break. As a result, BAND is converting to fueling with flow, to eliminate the potential of a power pulse and to allow for full-power operation. Concerns regarding the integrity of the end-of-life (EOL) bundles interacting with the latch at the downstream end of the fuel channel were raised. BAND carried out a test program in which EOL bundles in the upstream position of 13 of Unit 2 were cascaded into the downstream latch position 1 of another channel. Six of twelve cascaded bundles and two typical EOL position 13 (benchmark) bundles were selected for post-irradiation examination (PIE). Incipient cracks were found in the benchmark bundles. Metallographic and fractographic examination, along with crack dating, and hydrogen and deuterium analyses, indicated that the incipient cracks were the result of delayed-hydride assisted cracking at the EOL. Consequently, Ontario Hydro changed the design of the outlet shield plug to support all three rings of the fuel bundle, to minimize stress and prevent end plate cracking. Also, an ultrasonic end plate inspection tool (UT) was developed and located in the fuel bay, to inspect fuel-bundle end plates for cracks. A second test was done involving a series of four bundle cascades in BAND Unit 4 channels that had new outlet shield plugs. The latch bundles were discharged after a hot shutdown. The cascaded Unite 2 and Unit 4 latch bundles were checked for cracks using the UT. The PIE found incipient cracks or less-than-ideal welds in the assembly welds of fuel elements from Unit 2 (latch-supported fuel bundles) that had been identified by the UT as having incipient cracks. No incipient cracks were found in the assemble welds of fuel elements from Unit 4 (new outlet shield-supported fuel bundles) confirming the UT results. (author). 5 refs., 8 figs

[en] Highlights of the Canadian nuclear power program are featured. Over the year, capacity factors were 85.6%, 90.9%, 95.6% and 90.8% for Pickering A units 1-4 respectively. Three units of Bruce A are in service, with the fourth due to start up in December 1978. Progress with the construction of Gentilly 2, Point Lepreau and Pickering B is reported. Future developments will include a Gentilly 3, and 3.4 GW at Darlington. The Cordoba reactor has now been delivered, and site facilities are taking shape in Korea. Export sales to Romania, Italy, or Japan are considered to be a definite possibility. A nuclear communications centre to be opened by Ontario Hydro at Pickering during the summer of 1978 is designed to assist public understanding and acceptance of nuclear power. (N.D.H.)

No abstract available