Bruce Nuclear Generating Station

Construction of Bruce A began in 1969, making it the successor to the Pickering A plant.[9] Bruce A units were originally rated at 750 MWe net / 805 MWe gross,[12] which was later increased to 769 MWe net / 825 MWe gross.[3] As of 2017 the Bruce A units were capable of producing up to 779 MWe net according to IESO generator data. Each reactor requires 6240 fuel bundles that weigh 22.5 kg each, or about 140 tonnes of fuel. There are 480 fuel channels per reactor, containing 13 bundles each. There is storage capacity for about 23,000 bundles. Approximately 18 bundles are discharged per reactor per day.[13]

The Bruce A steam generators utilize a separate large horizontal shared steam drum (with one steam drum common to four steam generators), a design dropped in most other plants at the time. Issues related to the AECL requested design of the tube supports caused repair and delay costs, which exceeded the net worth of the builder Babcock & Wilcox Canada.[14]

Until they were removed in 1998, Bruce A reactors used unique booster rods to control reactivity.[15] Booster rods contained 93% uranium-235, and were inserted to overcome xenon poisoning. Bruce B and all other Ontario Hydro reactors instead use absorber rods called "adjusters" which are normally inserted and are removed to overcome xenon poisoning.[16]

Bruce A demonstrated an "excellent" early operating history. Together with Pickering A, the eight units achieved an overall average capability factor of 83% over the initial five-year period.[7] However, by 2001, when Bruce Power took the lease, all Bruce A units were laid-up.[3]

In 1981, Unit 1 was ranked the top reactor in the world with a 97% availability factor.[17][18] In December 1997, after about 20 years of operation, it was out of service. In 2005 (after 7 years of being idle) refurbishment started. In September 2012 (15 years out of service) it resumed operation.[19]

In 1982, Unit 2 was temporarily shut down due to a pressure-tube leak. In 1986, a fuel channel failed while the reactor was shut down; some of the fuel elements were swept into the moderator (calandria) and were difficult to remove.[20][16]

In 1986, maintenance workers accidentally left a protective lead blanket in the steam generator of Unit 2. By the time the mistake was discovered six years later, the blanket had melted, severely damaging the boiler.[21][22][23] In October 1995, after about 18 years of operation, unit 2 was taken out of service.[24] In 2005 (after 9 years of being idle) refurbishment started. In October 2012, it resumed operation.[19][24]

In 1982, Unit 3 set a then world record of 494 days of continuous operation and as of 1984 Bruce A was the most reliable multi-unit station in the world.[21] From April 1998 onward, Bruce A3 remained idle for 6 years, returning to service in January 2004 (at which time the unit was 32 years old).[25] Planned refurbishment of the third unit is to begin in 2023 (when the unit will be 51 years old).[26][27][28]

In 1990, a software error in unit 4 caused a fueling-machine error, damaging a fuel channel.[20][29] In 1993, reactor power was reduced to 60% until various loss-of-coolant accident (LOCA) scenarios could be addressed. Subsequently, Bruce A units returned to 89% of rated power.[20] In March 1998, after about 19 years of operation, unit 4 was taken out of service.[30] It returned to service in October 2003, after 6 years of being idle (at which time the unit was 31 years old).[30] Planned refurbishment of unit 4 to begin in 2025 (when the unit will be 53 years old).[26][27][28]

Bruce B units are of a slightly larger capacity: 817 MW net, 840 MW gross.[12] which is attributed to an improved steam generator design, where the steam drum is integral to each steam generator in a "light bulb" arrangement, eliminating the horizontal cross-drum.[31][14] In 1990, a nine-week "impairment" of Bruce B was created when a technician incorrectly set the calibration on radioactivity monitors.[32] In 2007, Bruce B 7 was the top performing nuclear reactor in Ontario with 97.2% performance.[33] and in 2009, Bruce B 5 was first with 95.4% performance.[34]

Bruce B 5

• Construction began 1 June 1978.[35]
• On 15 November 1984 it reached first criticality.[35]
• Commercial operation began on 1 March 1985.[35]
• Originally scheduled to be shut down in 2016 (unit would have been 31 years old).[32]
• Planned refurbishment to begin in 2026 (unit will be 41 years old).[26][27][28]

Bruce B 6

• Construction began 1 January 1978.[36]
• On 29 May 1984 it reached first criticality.[36]
• Commercial operation began on 14 September 1984.[36]
• Originally scheduled to be shut down in 2018 (unit would have been 34 years old).
• Planned refurbishment to begin in 2020 (unit will be 36 years old).[26][27][28]

Bruce B 7

• Construction began 1 May 1979.[37][9]
• On 7 January 1986 it reached first criticality.[37]
• Commercial operation began on 10 April 1986.[37]
• Originally scheduled to be shut down in 2015 (unit would have been 29 years old).
• Planned refurbishment to begin in 2028 (unit will be 42 years old).[26][27][28]

Bruce B 8

• Construction began 1 August 1979.[38]
• On 15 February 1987 it reached first criticality.[38]
• Commercial operation began on 22 May 1987.[38]
• Originally scheduled to be shut down in 2019 (unit would have been 32 years old).
• Planned refurbishment to begin in 2030 (unit will be 43 years old).[26][27][28]

As of 2017, the station (A and B combined) produced the following amounts of electricity annually:

• 2001 20.5 terawatt hours (TWh);
• 2003 24.5 TWh;
• 2004 (planned) 34 TWh.[3]
• 2007 35.47 TWh
• 2008 35.26 TWh[39]
• 2013 45 TWh, which was about 30% of Ontario's production.[40]
• 2015 47.63 TWh[17]
• 2017 49.02 TWh[41]

After Units 1–2 completed refurbishment activities and were brought back online in 2012, Bruce became the largest operating nuclear generation facility in the world by both the number of currently operational reactors and total net output capacity, having a total of 8 operational CANDU nuclear reactors with a combined output of 6,384 MW_e net (7,276 MW_e gross) when all units are online.[42][43] (The Kashiwazaki-Kariwa Nuclear Power Plant in Japan had a larger total output capacity, but it has been out of service since 2011.[44])

As of 2008, the Bruce station had three double-circuit 500 kV transmission lines to feed the major load centres in southern Ontario, in addition to three double-circuit 230 kV lines serving the local area.[45] These circuits are connected via two high voltage switchyards owned and operated by Hydro One. In 2006, OPA had proposed increasing transmission line capacity, at a cost of between $200–600 million,[46] described as "the largest electricity transmission investment in Ontario in the last 20 years."[47] The line was completed in June 2012, several months ahead of schedule, with over 700 towers built for the 180 kilometre line to Milton. The project ranked 45th in Renew Canada's annual list.[48]

In 2010, Bruce Power was paid approximately $60 million for contracted, but unused power.[49]

Compared to the other major Canadian nuclear power plant built earlier, Pickering station, the Bruce reactors have higher power output, achieved by: increasing the number of fuel channels, increasing the number of bundles per channel, and a change in the fuel bundle itself.

At Bruce, the fuelling equipment is shared by the four reactors of each plant, while at Pickering each reactor had a fuelling machine. The Bruce fuelling machine and fuel channel end fitting design (mostly by Canadian General Electric) is based on the Nuclear Power Demonstration design. The Pickering design by AECL was based on Douglas Point.[50]

The building design of the reactor differs: Bruce uses a squarish "close-in" design, in which as much of the equipment as possible is arranged outside the main containment envelope for easier access during maintenance and emergencies.[16] The steam generators penetrate the containment. The primary coolant pumps and primary piping systems are inside the containment enclosure, but the pump motors are outside containment and the drive shaft seals form the containment boundary.[51] Pickering has round domes which enclose much of the secondary cooling equipment.[52]

• The Pickering A system did not originally have a second independent shutdown system. The Bruce containment concept differs: the reactor's reactivity mechanism deck serves as a part of the containment boundary, is closer to the reactor, and more prone to damage in the event of an accident ("accidental physical disassembly"). The designers therefore foresaw the need for a second safety system to reduce the risk on an accident. Bruce received a second, fully independent Safety Shutdown System (SDS2) which uses a liquid neutron poison injection method.[53]
• The Bruce system also has a high-pressure Emergency Coolant Injection System (ECIS).[7]
• Each Bruce "4 pack" has its own Vacuum Building, while Pickering has one per eight reactors.[7]
• At Pickering, the vacuum duct was closed by nonreturn valves, to prevent flow of the steam/air mixture from the duct to a non-accident reactor unit following a LOCA. In the Bruce concept, there is no such non-return valve; the reactor buildings are all interconnected during normal operation.[16]
• Bruce uses single-circuit heat transport system, while Pickering had two circuits.[16]
• The first two reactor units of Pickering A originally used Zircaloy-2 pressure tubes. All subsequent CANDU units use a zirconium - 2.5% niobium alloy.[16]
• Bruce uses a pressurizer to maintain coolant pressure, Pickering a different system.
• The Pickering design utilized 12 small steam generators operated in groups of three which can be individually valved out of the heat transport loop, as can the 16 pumps per reactor, with 4 being spare. At Bruce, the number of steam generators and coolant pumps was reduced to 8 and 4 respectively, without any spare pumps, thereby simplifying the piping. The Bruce system permits reactor power level to be adjusted more quickly and easily.[16][54]

Bruce A was projected to cost C$0.9 billion (1969), and actually cost $1.8 billion (1978), a 100% over-run. Bruce B was projected to cost $3.9 billion (1976), and actually cost $6 billion (1989) in "dollars of the year", a 50% over-run.[32][55] These figures are better than for Pickering B or Darlington (at 350%, not accounting for inflation).

On January 1, 2016, Bruce Power began receiving a single contracted price for all output from the site of CA$65.73 per megawatt-hour (MWh).[56] This price is partially adjusted annually to account for inflation and wage growth, with additional monthly fuel cost adjustments, and it includes a small payment for Bruce's unique ability to curtail up to 2400 MW of generation (total across all eight units — up to 300 MW per individual unit) via steam bypass operation during periods of surplus generation.[57]

During the course of the refurbishment of Units 3–6 the price will be raised in steps to cover individual reactor refurbishment costs, with each increase starting 12 months prior to the start of each individual refurbishment (and lasting only until that unit's refurbishment costs (which are fixed prior to refurbishment start) have been recovered). The average price per MWh that will be paid to Bruce Power for all electricity generated from 2016–2064 (covering the entire refurbishment period for Units 3–6 plus the entire expected remaining post-refurbishment lifetimes of all eight Bruce Power reactors (including the two that were already refurbished)) was estimated to be approximately CA$80.6/MWh in 2017 dollars by the Financial Accountability Office of Ontario. In contrast, the estimated average price of nuclear electricity from all three Ontario nuclear plants during that same 2016–2064 period was estimated to be CA$80.7/MWh in 2017 dollars, the 2017–2018 unit cost of Ontario nuclear power was CA$69/MWh, and the current price of electricity for "most residential and small business customers" was CA$114.9/MWh (prior to the Fair Hydro Plan) or CA$97.6 (after the Fair Hydro Plan).[57]

During the Northeast Blackout of 2003 three Bruce B units continued running at 60% reactor power and 0% grid electrical power. They were able to do so for hours, because they had steam bypass systems designed to de-couple the reactor output from the generator electrical output.[58] The three units were reconnected to the grid within 5 hours.[20] Bruce A and B stations were designed to operate indefinitely while disconnected from the grid.[59]

"Contrary to popular belief, the electrical generators of nuclear plants can follow the load demands of the electrical grid provided specific engineered systems to permit this mode of operation are included in the plant design."[58]

Cobalt-60 (⁶⁰Co) can be produced in a CANDU reactor by using adjuster rods made primarily out of ⁵⁹Co (instead of the normal stainless steel), which is slowly transmuted into ⁶⁰Co via neutron activation (⁵⁹Co + n → ⁶⁰Co).[60][61] These now-intensely-radioactive cobalt-60 adjuster rods are then "harvested" (removed and replaced with fresh ⁵⁹Co adjuster rods) after one to three years of use in the reactor during a routine reactor shutdown, and are later processed into sealed ⁶⁰Co sources of varying intensities by Nordion.[60][62][63][64] The Bruce nuclear power plant has been producing ⁶⁰Co since the 1980s, and almost all of the world's supply of ⁶⁰Co comes from various CANDU nuclear reactors, with Bruce being the single largest supplier.[65][66][67][68][69] As of 2007, Bruce supplied over 40% of the world's ⁶⁰Co.[9] This rose to over 50% by 2016, with Pickering supplying approximately another 20% of global demand.[68] In 2016, Bruce extended their contract with Nordion for the continued supply of ⁶⁰Co to cover the entire projected post-refurbishment life of the Bruce reactors, which are expected to operate until 2064.[68]

Bruce also began producing High Specific Activity (HSA) ⁶⁰Co in 2016, which is designed for highly specialized medical uses such as cancer treatment and had been primarily produced at the NRU reactor for the past 60+ years (which was originally scheduled to be shut down in 2016, but will be kept online until March 31, 2018 due to the general worldwide lack of sufficient replacement medical isotope production capacity for several critical isotopes such as molybdenum-99).[70][71][72][73][74] As the NRU produces over two-thirds of the world's HSA ⁶⁰Co, Bruce's ability to supply HSA ⁶⁰Co will become critical to help fill the immense production gap left by the NRU once it is decommissioned in 2018.[72][73][74][75] OPG and Bruce Power are collaborating on an effort to expand ⁶⁰Co production to the Bruce A and Darlington reactors in order to fully cover Pickering's production (which will end when the plant is decommissioned in 2024) in addition to the inevitable gaps in ⁶⁰Co production capacity that will be caused by the upcoming refurbishments of six of Bruce's reactors (Units A 3–4 & Units B 5–8), as well as all four of Darlington's reactors.[68] They are also working on expanding the production of HSA ⁶⁰Co to more reactors.[76]

In 2017, Bruce Power became the first Canadian recipient of a Top Innovative Practice (TIP) award from the Nuclear Energy Institute (NEI) for its ongoing work with Nordion to produce cobalt-60.[77][78]

Bruce Power is working with Framatome to develop the capability to "produce shorter half-life radioisotopes (such as molybdenum-99, lutetium-177 and iridium-192)" using Areva's proprietary technology for the on-line production of radioisotopes in heavy water reactors.[79][80] Areva will design and supply the system for installation in the existing Bruce units.[80]

In June 2018, Bruce Power and ITG (a subsidiary of Isotopen Technologien München (ITM)) announced the start of a joint effort to explore producing lutetium-177 in Bruce's reactors, with ITG planned to manage the development, processing, and distribution of lutetium-177.[81]

In 2007, the Ontario Power Authority had recommended in a plan submitted to the Ontario Energy Board, to build a new nuclear power station consisting of at least two reactors.[109] The leading candidate was AECL's Advanced CANDU Reactor.[110] Since 2008, environmental assessments have been underway both at Bruce and at Ontario Power Generation's Darlington Nuclear Generating Station.[111]

In 2009, Bruce Power withdrew its application to the CNSC for the Bruce C plant.[112][113]

On October 26, 2016 Bruce Power announced an uprate from 6,384MWe to 6,400MWe.[114] On July 11, 2019 Bruce Power announced another uprate to the facility, adding 22MW of output to Unit 3, bringing overall site output to 6,430MWe.[115] The March 2019 Bruce Power Major Component Replacement Project: Economic Impact Analysis indicates a target capacity of 7,000MWe by mid-2033.[116]

Encompassed by the Bruce site is the shut-down Douglas Point reactor, an earlier version of the CANDU design. Construction began in 1960; was operational in 1967; and was shut down in 1984.[9] The present Bruce reactors each are roughly 4 times the capacity of the 200 MW Douglas Point unit.

The Bruce Heavy Water Plant (BHWP) also occupied the site. Atomic Energy of Canada Limited contracted the Lummus Company of Canada Limited in 1969 to design and construct the first phase of the plant, while Ontario Hydro was responsible for commissioning and operating.[117]

It was planned to consist of four sub-plants, A through D:

• A was in production in 1973, shutdown in 1984, and demolished in 1993;
• B was in production in 1979, partially shutdown in 1993, completely closed in 1997, and subsequently demolished;
• C was cancelled, and never built;
• D was 70% completed when cancelled, and subsequently demolished in 1995.

During its lifetime, BHWP produced 16,000 tonnes of reactor grade heavy water. Capacity of each sub-plant was planned to be 800 tonnes/annum. The plant size was approximately 960 m by 750 m.[1] The heavy water was 99.75% pure.[117] The production of a single kilogram of heavy water required 340 tonnes of feed water.[118]

Steam from Bruce A could be diverted to the Bruce Bulk Steam System (BBSS) to provide energy for the production of heavy water (750 MW thermal), to heat buildings within the development (15 MW th), or to provide energy (72 MW th) for the adjacent Bruce Energy Centre (BEC). The BEC supported industries such as greenhouses and plastic manufacturers. As one of the largest bulk steam systems in the world, this system could produce 5,350 MW of medium-pressure process steam, and had over 6 km of piping.[119]^:15–16 It was demolished by the end of 2006. Because of the requirement to provide steam, the Bruce A turbines were undersized relative to the reactor power.[17][31][120][121][122]

OPG owns the nearby 288 ha Inverhuron Provincial Park on Lake Huron, bordering Inverhuron, 14 km north-east of Kincardine, which is not part of the Bruce site proper, and leases it to the Ontario Ministry of Natural Resources. As a condition of the operating licence for Bruce Nuclear, OPG retained a 914 m radius exclusion zone in the northwest corner of the park. after operating over 25 years the park campground was phased out in 1976, because of safety concerns related to the heavy water production. When heavy water was no longer produced, the park campground was allowed to re-open in 2000 on the same spot.[123]^:7

The heated water released back into Lake Huron by the plant prevents the surrounding shoreline from freezing over during winter and attracts an inordinate concentration of lake fish, which in turn attracts droves of bald eagles wintering in the area. Numbers peak around late February to early March and it is not uncommon for visitors to observe several dozen eagles in and around the general vicinity of the plant at any given time during these months.[124][125]