Darlington NPP Design Data


The table below provide design data for Darlington NPP.

Location Town of Newcastle, Ontario
Owner, operator Ontario Hydro
Designers Ontario Hydro
Number of units Four
Rated output per unit Generator output 935 MW(e)
Self-consumption 54 MW(e)
Net electrical 881 MW(e)
Overall net efficiency 31.70%
Fuel Natural Uranium Dioxide (UO2
Moderator Deuterium Oxide (D2O-heavy water)
Coolant Pressurized heavy water
Type Horizontal pressure tube
Construction Start of construction late 1977
Schedule In-service dates:
Unit 1-1990 Unit 3-1991
Unit 2-1990 Unit 4-1992
Building and Structures
Powerhouse
Overall length 563 6 m (1899.3 ft.)
Overall width 137.0 m (461.7ft.)
Reactor building
Form Rectangular
Material Reinforced concrete
Length 49.8 m (163.4 ft.)
Width 28.6 m (93.8 ft.)
Height 51.1m (167.7ft.)
Design pressure -53.1 kPa(g) to + 96.5 kPa(g)
(-7.7 psi(g) to + 14.0 psi(g))
Reactor auxiliary bay
Form Rectangular, 5 story, steel frame, concrete floor & 2 story concrete basement.
Length 91.2 m (299.2 ft.)
Width 50.65 m (166.2 ft.)
Height 58.2 m (190.9 ft.)
Turbine hall
Form Rectangular, steel frame, concrete and grating floor.
Length 91.2 m (299.2 ft.)
Width 54.8 m (180.0 ft.)
Height 44.9 m (147.0 ft.)
Turbine auxiliary bay
Form Rectangular, steel frame, concrete and grating floors and basement
Length 91.2 m (299.2 ft.)
Width 18.8 m (61.7 ft.)
Height 45.9 m (150.0 ft.)
Central service area
Form Rectangular, steel frame, concrete floors.
Length 63.0 m (206.7 ft.)
Width 136.5 m (447.8 ft.)
Height 45.9 m (150.0 ft.)
Vacuum structure
Form Cylindrical prestressed concrete
Diameter 50.4m (170.0 ft.)
Height 71.2 m (239.9 ft.)
Free volume 95 000 m3 (3.35 x 105 ft.3)
Design Pressure -101.4 kPa(g) to + 96.5 kPa(g)
(-14.7psi(g) to + 14.0 psi(g))
Water storage 11500 m3 (4.06 x 105 ft.3)
Fuelling facilities auxiliary building
Form Rectangular, concrete floors & walls below grade, steel frame with concrete floors above grade.
Location One at either end of the powerhouse.
Length 66.7 m (218.83 ft.)
Width 54.0m (177.16 ft.)
Height 22.85 m (74.92 ft.)
Reactor vessels
Calandria shell
Form Horizontal, stepped cylinder comprising of main shell, two sub-shells & two annulus plates.
Material Austenitic stainless steel
Inside diameter 8 458 mm (27.75 ft. )
Main shell thickness 31.75 mm (1.25 in.)
Length 5981 mm (19.50 ft.)
Calandria end shields
Purpose Integral with calandria shell, provides support for alignment of fuel channels & shutdown shielding of the reactor faces.
Material Austenitic stainless steel (filled with steelballs & light water 60:40 by volume)
Weight (filled) 2 370 Mg (5,241,000 lb.)
Length (each) 1 016 mm (3.33 ft.)
Calandria tubes
Quantity 480
Material Zircaloy-2, seamwelded
Inside diameter 129 mm (5.077 in.)
Wall thickness 1.37 mm (0.054 in.)
Reactor Core
Pressure tubes
Purpose Fuel channels & primary heat transport
Quantity 480 tubes (24 x 24 array)
Material Zirconium-Niobium alloy
Inside diameter 103.4 mm (4.07 in.)
Wall thickness 4.2 mm (0.16 in.)
Lattice Pitch 285.8 mm (11.25 in.)
Core Radius 3 532 mm (139.06 in.)
Core Length 5 944 mm (234.0 in.)
Average reflector thickness 700 mm (27.6 in.) at midpoint
Fuel load 6 240 bundles (108 Mg U) (237,600 lb. U)
Moderator and Reflector D2O 312 Mg D2O (686,400 lb. D2O)
Maximum channel power 6.4 MW
Average burn-up
Reactor control 164 MW.h per kg. U
Reactivity control Units 2 digital computers per unit
Shutdown systems - shut-off rods
Purpose Safety devices to quickly terminate reactor operation
Quantity 32 rods
Type Stainless steel - cadmium - stainless steel sandwich in the form of a tube
Orientation Vertical through lattice
Reactivity worth -49 mk within 2.0 sec.
Drive mechanism Winch & cable driven via an electro magnetic friction clutch by a constant speed induction motor
Shutdown system - liquid injection
Purpose Safety system to terminate reactor operation
Type Gadolinium nitrate solution
Reactivity worth -55 mk
Injection method Pressurized helium to drive solution into bulk moderator through nozzles
Control system - liquid zone control units
Purpose Suppress unwanted changes in neutron flux distribution
Quantity 14 separate zones
Type Natural water compartments
Orientation Vertical
Reactivity rate of Change - 0.1 mk per sec.
Reactivity worth 6.3 mk (full to empty)
Control system - control absorber rods
Purpose Inserted if reactivity rate of change of Liquid Zone Control system is inadequate
Quantity 4 rods
Type Same as Shut-off Rods
Reactivity rate of change + 0.1 mk per sec.
Reactivity worth -9 mk (inserted)
Control system - adjuster rods
Purpose Normally inserted to limit fuel power; can be withdrawn to provide increased reactivity
Quantity 24 rods
Type Stainless steel
Reactivity rate of change 0.04 mk per sec.
Reactivity worth + 17 mk
Moderator
Type Heavy water
Total volume 312.0 m3 (11,019.5 ft.3)
Purity 99.95% D2O by weight
Heat load (max. design) 138.0 MW (th)
Primary coolant
Type Pressurized heavy water
Quantity 25.2 kg/s (199,210 lb./hr)
Flow per channel (max.) 280 Mg (617,290 lb.) at 37.80C (1000F)
Reactor inlet Coolant temperature 267 degrees C (513 degrees F)
Reactor outlet temperature 310 degrees C (590 degrees F)
Reactor outlet header Pressure 10.0 MPa(a) (1 450 psia)
No. of pumps 4 per unit
Steam generators
Quantity 4 per unit
Steam pressure at drum (design) 5.068 MPa(a) 735 psia)
Steam temp. at drum 264.75 degrees C (508.5 degrees F)
Total steam output 1 310.4kg/s (10.33 x 106 lb./hr)
Feedwater inlet temperature 176.7 degrees C (350 degrees F)
Fuel elements
Type 37 element bundles, 495 mm (19.5 in.) long
No. per channel 13 bundles
Diameter of bundle 102.49 mm (4.05 in.)
Weight of U02 per bundle 21.23 kg (46.71 lb.)
Total weight of bundle 23.5 kg (51.7 lb.)
Maximum bundle power 787 kW (time averaged)
Turbine generator
Turbine One tandem compound unit per with external moisture separation steam reheat (2 stages)
No. of high-pressure cylinders 1 double flow
No. of low pressure cylinders 3 double flow
Speed 1 800 RPM
Throttle steam pressure 4.83 MPa(g) (700 psig)
Type of condenser Two pass
Cooling water flow 31.6 m3/sec. (417,392 gpm)
Generator One per turbine
Rating (85% power factor) 1101 MVA
Terminal voltage 22 kV
Frequency 60 Hz
Transformers
Main output 12-330,000 kVA, 1 phase, 60 Hz, 21.45/525 kV (3 per unit)
Unit service 4-80,000 kVA, 3 phase, 60 Hz, 22113.8/13.8 kV
System service 4-80,000 kVA, 3 phase, 60 Hz, 500/13.8/13.8 kV
Circuit breakers
500 kV 18 - 2 cycle, 4000 A, 100 kA, SF breakers
13.8 kV 154 - 750 MVA, 1200 A and 2000 A
4.16 kV 298 - 250 MVA, 1200 A and 2000 A
Standby power
Combustion turbines 4 - 26 MW, 13.8 kV
Emergency power generators 2 - 6.8 MW, 4.16 kV
Acknowledgement Information on this page graciously provided by Ontario Hydro.

 


Copyright 1996-2004.  Joseph Gonyeau, P.E.. The Virtual Nuclear Tourist. All rights reserved. Revised: December 6, 2001.