Image Library

CANDU6 Fuel in Fuel Channel

AECL

1024 x 768

129 KB

PWR Fuel Bundle

AECL

1024 x 768

321 KB

CANDU Fuel Bundle - 37 Element

AECL

1024 x 768

300 KB

CANDU Fuel Bundle - 37 Element

AECL

1024 x 768

245 KB

CANDU Fuel Bundle - 37 Element

AECL

1024 x 768

298 KB

ACR-1000 CANFLEX ACR Fuel Bundle

AECL

1275 x 959

90 KB

NRX fuel section cross section

UNENE

385 x 265

163 KB

37-element CANDU fuel bundle

UNENE

774 x 542

128 KB

ACR CANFLEX fuel bundles

UNENE

659 x 382

71 KB

Typical CANDU fuel bundle

UNENE

1280 x 720

130 KB

Douglas Point Fuel Bundle

OPG

3736 x 2647

1421 KB

Douglas Point Fuel Bundle

OPG

4268 x 2011

2365 KB

Douglas Point Fuel Bundle - Cross Section

OPG

3496 x 2751

1658 KB

AECL Symbol

The figures denoted by 37000-fuel below form a "Historical and Pictorial Record of Canada's Power Reactor Fuel Bundle Design and Development", edited by R.D. Page and A.J. Langdon, photography by C. Baskin, CRNL. This pictorial record of Canada's power reactor fuel bundles was prepared to historically record the evolution of the power reactor fuel over the years. No one report issued over the years has been able to describe in detail the various changes that these pictures portray. It should be noted that the record does not include WR-1 type fuel or special irradiation of assemblies. "A picture speaks a thousand words".

AECL

1093 x 1293

198 KB

End-Plates of the First 3 Inch Diameter Fuel Bundles

This is a photo of the end-plates of the first 3 inch diameter fuel bundles. These were the first 19 element fuel bundles built in Canada and irradiated in the E-20 loop (now U-2) in the NRU reactor. They had to have a diameter of 3 inches to fit in the thick wall pressure tube installed in the E-20 loop to commission it. As the knowledge of the material properties of Zircaloy-2 was not well known at that time, the wall thickness was increased to be conservative. The bundles were assembled by screws as the method of welding the end-plates had not been developed. (circa 1959-60).

AECL

1402 x 782

122 KB

NPD-7 Element End View

This is an end view of one of the first NPD 7-element fuel bundles. They were assembled by riveting the elements to the thick end-plates. Later Tungsten-Inert-Gas (TIG) welding was used and later resistance welding to thinner end-plates, thus improving the neutron efficiency of the fuel.

AECL

1224 x 1209

152 KB

NPD-7 Element Riveted

This NPD 7 element riveted bundle is in its classic autoclave black.

AECL

1396 x 1089

90 KB

NPD-7 Element End View

This end plate on the NPD 7 is now assembled by TIG welding to a thinner end plate.

AECL

832 x 890

74 KB

NPD-7 Element T.I.G. Welded

In some colour photos the rusty colour on the surface of fuel bundles is from endurance testing in the lab and comes from the iron oxide from the carbon steel piping, even though the bundles rested in a Zircaloy pressure tube.

AECL

1140 x 744

70 KB

NPD 19 Element End View

The end view of a NPD 19 element assembled by TIG welding.

AECL

1104 x 1099

135 KB

NPD 19 Element

The 19 elements are spaced by two wires wrapped around each elements and spot welded to the sheaths, one turn per length of element.

AECL

1384 x 679

82 KB

fig008_Douglas_Point_19 el_wire_wrap.jpg

Douglas Point 19-Element Wire Wrap

The Douglas point 19 element bundles were wire wrapped but the helix around the element was doubled. Thicker wires were attached at each end to act as bearing pads so the bundles could slide through the pressure tubes with minimum wear to the tubes.

AECL

1390 x 710

86 KB

Douglas Point 19-Element Wire Wrap

An example of the DP 19 element bundle covered in the iron oxide and showing the extra wire pads which are partially ground to a flat surface contoured to fit the pressure tube.

AECL

1119 x 776

66 KB

NPD and DP 19 Element Wire Wrap

A comparison of the NPD & DP 19 element bundles. Note that the DP bundle now assembled by resistance welded of end plates to the elements.

AECL

1284 x 1103

154 KB

AMF Brazed Twisted Tape 19 Element

During the development of the wire wrapped 19 element bundles for Douglas Point, there was growing concern of the possibility of inter-element fretting of the thin .015 in. thick fuel sheaths. A study was launched to come up with different ways of spacing the elements and also to delete the end plates. The following bundles are an illustration of what were considered. The first example is the twisted tape bundle for so-called better mixing. The center element was made strong enough to take the fueling machine loads and the outer elements were recessed for the fueling machine side stops. Did not graduate.

AECL

1336 x 651

78 KB

Welded-Belly Banded AMF Bundle

Another design during this period was held together by belly bands and used welded spacers. Did not graduate. AMF stands for American Machine and Foundry who was contracted to produce Uranium metal fuel for NRX and NRU Research reactors at Chalk River. They were later bought out by Canadian Westinghouse.

AECL

1411 x 789

108 KB

Early Brazed - AMF 19 Element

Another design using brazing of the ferrule spacers to the elements were tried. Again did not graduate. But Zr-Be brazing was introduced.

AECL

1371 x 450

58 KB

Domed End Cap Brazed AMF Bundle

To reduce the amount of Zircaloy in the end caps of the elements, thin domed end caps brazed to the sheath were tried. They had insulating pellets inside. The bundle was assembled with two planes of fixed spacers and bearing pads on the outside elements. All brazed to the sheath using both resistance heating and induction heating to melt the braze alloy.

AECL

1363 x 894

90 KB

Domed End Cap End View

The end view of the above bundle with fixed brazed spacers and domed end caps.

AECL

1130 x 1108

106 KB

2 Fixed Plane Resistance Brazed 19 Element AMF

This bundle has two planes of spacers. The domed end caps have been replaced by normal solid ones to better survive the fueling machine side stop loads and remove the need of brazing the elements ends. The bearing pads were now standard.

AECL

1375 x 757

80 KB

fig017_End_View_2_Fixed_Plane_Brazed_19 el.jpg

2 Fixed Plane Brazed AMF 19 Element End View

The end view of the same bundle. The chamfer on the end caps was to accommodate the chamfer on the side stops.

AECL

1091 x 1060

93 KB

D.P. Replacement Brazed Split Spacer

After a number of defects during irradiation in NRU the design was abandoned and end plates were reintroduced. This bundle had no spacing and was not irradiate.

AECL

1367 x 727

96 KB

fig019_DP_ Dev_small_mid_plane_Bearing_Pads.jpg

D.P. Development Brazed Split Spacer

The design of the replacement bundle for Douglas Point and NPD was slowly beginning to make progress. The fixed plane was dropped and replaced with a split spacer and a small pad in the center plane only. Thus the elements could now expand independently.

AECL

1383 x 884

88 KB

Tube in Shell

Whilst all this development was going on a radical bundle design was tried. It was called the Tube-in Shell bundle. Instead of passing the heavy water coolant over and around the fuel, it was decided to try passing the cooling water through the fuel. This bundle was filled with vibratory compacted UO2 powder, thus it had relatively low Uranium density compared to the sintered pellets. It was all brazed in assembly which was very difficult. After two defects during irradiation the design was dropped from further development. It had a major weakness with respect to heat transfer, the coolant tubes had excellent heat removal but the eccentric outer annulus was very poor.

AECL

1386 x 750

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End View Tube in Shell

This an end view of the Tube-in-Shell bundle. The traces of the braze alloy are evident around the tube ends.

AECL

1171 x 1129

133 KB

D.P. Replacement Brazed Split Spacer

The design has now matured and the spilt-spacers are now canted to prevent interlocking and a full length bearing pad has been added in the center plane. This bundle has seen endurance testing in the Sheridan Park loop and the braze alloy has a higher corrosion rate than the normal Zircaloy, thus the white appearance at the joints of the bearing pads.

AECL

1134 x 784

74 KB

Douglas Point 19-Element End View

This is a Westinghouse made bundle after they took over from AMF. Note the grounding electrode marks on the end caps from resistance welding of the end plate to the elements.

AECL

1213 x 1128

128 KB

Development Bundles

These end views are of two CGE development bundles where the use of welded bearing pads and spacers were tried. Also a variant of the end plate in two pieces. Note that the inner element caps are flat. This design did not go into production.

AECL

1404 x 856

124 KB

D.P. Production Brazed Split Spacer

The final production bundle was a brazed split spacer design with three planes of bearing pads. This design of bundle was used as replacement fuel for both Douglas Point and NPD power reactors in Canada. It was also used in Kanupp, Pakistan and Rapp I & II, India.

AECL

1397 x 757

77 KB

NPD-7, D.P. 19 Wire Wrap and D.P. 19 Brazed Split Spacer

AECL

1297 x 991

117 KB

NPD-7 W.W., NPD-19 Douglas Point-19 W.W. D.P. 19, 3 Fixed Plane DP-19 Split Spacer

AECL

1392 x 643

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Wire Wrap 28 Element - Development

During the development of the replacement D.P. design there were two other reactor fuel projects being developed. They were fuel bundles for Pickering A and Gentilly - 1 Boiling Light Water (BLW) reactors. Both these reactors were going to use 4 inch diameter pressure tubes vs the 3.25 inch of D.P. & NPD. Keeping the same size of elements as the D.P. 19 and .050 inch spacing between elements, the 28 element Pickering design was developed. CGE still preferred the wire warp rather than the toxic Beryllium braze. This wire wrap design was not favoured.

AECL

1351 x 985

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Wire Wrap 28 Element End View

The end plate for the 28 element Pickering bundle took many forms which are illustrated in the following photos.

AECL

1236 x 1113

115 KB

28 Element Development Bundle Flexible Spacer

CGE tried very hard to come up with a satisfactory design using only welding as the means of assembly. The angled bearing pads were welded at two points. The flexible spacer did not survive irradiation or endurance testing. The lack of redundancy in the bearing pads received a negative point in the design review. The end plate design changed again.

AECL

1322 x 944

97 KB

28 Element Development Bundle

28 element with welded spacers and bearing pads. Note that one of the pads welds have failed and the pad is missing. Note two piece end plate.

AECL

1325 x 924

85 KB

28 Element Development Bundle End View

A close up of the two piece end plate on the welded 28 element development bundle.

AECL

1305 x 1219

127 KB

fig106_CGE_28_el_straight_welded_bearing_pads_dev_bundle.jpg

28 Element Development Bundle Welded Bearing Pads

CGE still trying to develop the welded 28 element bundle, now with welded straight pads and more than one plane of inter-element spacers. Single piece end plate.

AECL

1380 x 985

90 KB

Pickering 28 Element

Westinghouse came up with the final production design of the Pickering 28 element bundle. It had brazed spacers and bearing pads and a classical simple end plate design proposed by an accountant.

AECL

1232 x 722

94 KB

28 Element Development Bundle

GE was now using brazed pads and spacers and again a different end plate design. CGE traded wire wrap technology with Westinghouse for brazed technology.

AECL

1360 x 925

91 KB

28 Element Pickering Production in P.T.

A closeup of the classical Pickering 28 element end plate with the bundle inside a Zr-Nb 2.5% pressure tube. Note the thickness of the pressure tube. The hoop stress on pressure vessels is directly proportional to diameter; hence the small diameter pressure tube walls can be much thinner than the thick walls required for a PWR pressure vessel. Thin Zr walls do not absorb many neutrons; hence the moderator can be placed outside the fuel area in a low pressure calandria. This is the essence of pressure tube reactor design vs. pressure vessel reactor design.

AECL

1356 x 1085

127 KB

Gentilly-1 with CST

The fuel for the Gentilly-1 was maximized by large diameter elements with a central structural tube to hold the 10 bundles in the vertical pressure tubes. The fuel worked well but, with the success of Pickering proven by the mid 70's, the 10 % (approximately) lower TUEC of BLW-type reactors was not big enough to warrant continued operation nor to justify the funding of continued development. In addition, G-1 experienced control problems (related to coolant voiding and the use of direct cycle heat transport system) and serious service water system corrosion problems. Hence, the plant was shut down and decommissioned.

AECL

2444 x 1643

487 KB

Early Wire Wrap 37 Element

As a backup design to the 28 element Pickering bundle, a 37 element was proposed. This was a hand built solid steel bundle with mechanical wire wrap. The 37 element was later developed for the Bruce and 600 Mwe reactors.

AECL

1267 x 1124

116 KB

Gentilly-1

B&W of Gentilly -1 Boiling Light Water 18 element fuel bundle.

AECL

1387 x 753

78 KB

Bruce 28 Element Bundle

nitially it was thought that the 28 element bundle would meet Bruce requirements but when the design of the reactor was uprated, it was necessary to develope the Bruce 37 element, to meet the channel power requirements. Note the staggered plane of bearing pads at end of the bundle to meet Bruce Channel requirements.

AECL

1372 x 1007

95 KB

Bruce 37 Element Bundle

The Bruce 37 element had minor differences from the other 37 elements that were developed. The end caps were squared and the bearing pads were staggered at each end of the bundle.

AECL

2288 x 1389

322 KB

Bruce 37 Element Bundle End View

The end view of the Bruce 37 element bundle. Note the grounding electrode marks of the resistance welder.

AECL

940 x 948

117 KB

Bruce 37 Element Bundle with Hands

This photo gives a perspective of the size of the Bruce 37 element bundle relative to the man’s gloved hands. The bundles weighed approx 50 lbs and were 49.5 cm long and 10 cm in diameter.

AECL

1105 x 811

99 KB

Bruce Booster End View

The Bruce booster rods were designed to extend the window of the period shut before the Xenon poison prevented reactor startup. They were manufactured from enriched uranium Zircaloy alloy which was co-extruded with Zircaloy. The six 18 element bundles in an assembly was held together by ferrules and belly bands and strung together on a central structural tube. They had limited use in Bruce and were withdrawn from service.

AECL

1093 x 1047

135 KB

Bruce 37 Element Bundle and Booster

The comparative sizes of a Bruce Booster bundle and the 37 element bundle.

AECL

1005 x 1074

125 KB

Bruce Booster Rod Assembly

This drawing of the Bruce Booster Rod Assembly demonstrates how it is assembled into a complete rod of six bundles.

AECL

2156 x 2740

564 KB

Gentilly-2 600 MWe Reactor 37 Element Bundle

The Gentilly 2 600 MWe reactor 37 element bundle differed from the Bruce 37 in that the end caps were conical to accommodate the fueling machine side stops and the end bearing pads were not staggered. When the Bruce 37 and the 600 MWe 37 were irradiated together, this irradiation was paid for by the Common Programme between Ontario Hydro and AECL. This programme grew into the CANDEV (CANDU Development) programme funded by the utilities and AECL. This was later formalized into the CANDU Owners Group (COG) programme of all the nuclear utilities, this supported and funded common development programmes. The 600 MWe 37 element fuel bundle is been used in the folowing reactors: Gentilly-2, Quebec; Point Lepreau, New Brunswick; Cordoba, Argentina; Cernavoda, Romania; four reactors at Wolsung, South Korea; and two in China.

AECL

1374 x 703

120 KB

fig120_Bruce_booster_Pickering_28_Bruce600_MWe_37_els.jpg

Gentilly-1 with CST, Pickering 28 Element, Bruce 37 Element, Gentilly-2/600 MW(e) Prototype

A comparison of the Bruce booster bundle with the power reactor fuel bundles for Pickering A & B, Bruce A& B 37 element and the Gentilly-2 600 MWe reactors.

AECL

1397 x 883

163 KB

Bruce Fueling Machine

AECL

1492 x 1182

210 KB

Fuel Engineering Coat of Arms

The coat of arms is protected by AECL Proprietary and Final Preliminary Draft. The shield is divided into quadrants by red tape. Superimposed on it is a bastard bundle. The upper left quadrant represents the engineering terms of fuel behaviour. The upper right quadrant represents terms developed in manufacture of fuel. The lower left quadrant represents terms of heat transfer and corrosion. The lower right quadrant represents the mystical chemical symbols of the coolant chemistry. Above the shield is the Omnipresent bull moose of our founder Dr. Ara J. Mooradian. Superimposed is a bird cage representing a fuel carriage. Above which is the loop rampant and unstable. Underneath the shield is the banner burnt at both ends by Burnup and Burnout. Upon which the motto is inscribed ‘Caveat Emptor’ - ‘Let the buyer beware’ or ‘If it fails do not blame us!’ Below which rests ‘The never completed final report’.

AECL

1195 x 1736

253 KB

Double Length Bundle

There was always the question of double length bundles as the fueling machines magazines were two bundles long. I always had great doubts of it’s practicability. Late in the programme a couple of bundles were built. The dimensional stability of the bundle was poor due the long elements. There was a large problem in trying to find a means of making a rigid plane in the center plane of the bundle to improve the stability of the elements. The handling of the 100 lb. bundle presented too many problems both in manufacture and at the stations. It was not developed further.

AECL

992 x 1286

120 KB

25-Ton Flask over NRU Research Reactor

The 25 ton flask is used to remove irradiated fuel strings from the U-2 and U-1 loop test sections in the NRU research reactor at Chalk River.

AECL

1154 x 1443

241 KB

J-Rod Flask over NRU Research Reactor

The NRU reactor was the first reactor in the world to use on-power fueling. That was way back in the late 1950's. It is still operating as of August 2001 but it is reaching the end of its useful live and needs replacing. All the power reactor fuel bundles were tested for performance in this reactor, either in the U-2 or U-1 light water cooled loops. Each loop test section could accommodate six bundles vertically in a string.

AECL

1139 x 1442

199 KB

Universal Hot Cells

The Universal Hot Cells were used to examine irradiated fuel bundles and to disassemble the strings of fuel. The fuel bundles were examined and measured for dimensional changes and individual elements were cut out of the bundles for more detailed examinations.

AECL

1441 x 1183

264 KB

Bundle in Hot Cells

A 19 element fuel bundle being remotely moved by special tongs in the hot cells. This bundle had been irradiated to over 8,500 Mwd/tonne U at a heat rating of 43 W/cm. Note the circumferential ridges at the UO2 pellet interfaces.

AECL

1437 x 1125

143 KB

Milling the End Plate

To disassemble a fuel bundle in the hot cells remotely, the end plates were cut apart by a milling machine.

AECL

1437 x 1114

156 KB

Fuel Bundle Carriage

For fuel bundle testing in the verticle loops at NRU, six fuel bundles were assembled via a fuel carriage tensioned at one end with a spring, sometimes called a ‘birdcage’. The six bundle assembly was essentially 1/2 of a CANDU fuel channel.

AECL

1432 x 1049

139 KB

Bundle Strength Testing

Each type of bundle was strength tested in a compression test rig at temperature before and after irradiation. Irradiated bundles were some times stronger than the limit of the machine capabilities. These test was necessary to ensure that the bundles could withstand the fueling machine and hydraulic loads.

AECL

1438 x 1040

179 KB

Development of Fuel Bundle for Power Reactor

Generic diagram of what the central role that fuel played and what teams had to coordinate to get the various fuel programmes designed and into production.

AECL

2860 x 2208

749 KB

AECL Fuel Development Organisation

Specific diagram of what the central role that fuel played and what teams had to coordinate to get the various fuel programmes designed and into production.

AECL

2838 x 2241

571 KB

Spent Fuel Handling

1163 x 886

402 KB

CANTEACH Home

New Images

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Turbine generator for nuclear unit

ACR CANFLEX fuel bundles

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600 MW steam turbine for nuclear unit

Moderator cooling and purification system

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Comparison of core sizes

Feeder tube assembly on reactor face

Moderator and coolant circuits

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Typical refueling machine and bridge

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Nuclear reactor components

CANDU6 Containment System

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CANDU6 Turbine-Generator, Feedwater

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Douglas Point Fuel Bundle

Douglas Point Fuel Bundle

Douglas Point Reactor Core

Douglas Point Coolant Assembly

Douglas Point Fuelling Machine

Pickering A Aerial View

Douglas Point Fuel Bundle - Cross Section