Atomic Energy of Canada Limited CANADIAN POWER REACTOR PROGRAM- PRESENT AND FUTURE by E.C.W. PERRYMAN Presented at the 27th Annual Congress of the Canadian Association of Physicists, Edmonton, Alberta, on 27 June 1972 Chalk River Nuclear Laboratories Chalk River, Ontario September 1972 AECL-4265 CAI" ADIAN POWER REACTOR PROGRAM - PRESENT A. .D FUTURE1 by E.C.W. Perryman ABSTRACT A brief historical review of the Canadian Power Reactor Program is given, covering heavy-water moderated reactors cooled with heavy water, light water and organic liquid. The experience obtained from NPD and Douglas Point is discussed in relation to the first year's successful operation of the Pickering Nuclear Power Station. Future improvements and trends in the CANDU family of reactors are described. 1 This talk was presented at the 27th Annual Congress of the Canadian Association of Physicists, Edmonton, Alberta, on 27 June 1972. Chalk River Nuclear Laboratories Chalk River, Ontario September 1972 AECL-4265 Programme canadien des reacteuirs de puissance — Le present et l'avenir1 par E.C.W. Perryman Resume On passe brievement en revue le programme canadien des reacteurs moderes par eau lourde dont le caloporteur est de l'eau lourde, de l'eau legere ou un liquide organique. L'experience acquise grace a NPD et a Douglas Point est commentee a la lumiere du foncttonnement initial heureux de la centrale nucleaire Pickering. Les ameliorations futures et les tendances de la filiere CANDU sont decites. 'Cette conference a ete presentee lors du XXVIIe Congres annuel de 1'Association canadienne des physicien.% tenu a Edmonton, Alberta, !e 27 juin 1972. L'Energie Atomique du Canada, Limitee Laboratoires Nucleaires de Chalk River Chalk River, Ontario septembre 1972 AECL-4265 INTRODUCTION Nuclear power is no longer a curiosity; it has now ment. Other countries recognize this by their seeking reached a fully commercial stage in Canada and the technical and commercial agreements with us. At the rest of the world. In the world today, excluding the present time AECL has agreements with the USA, USSR, there is a total of 25,217 MWe operating. By UK, France, Italy, Japan and India, so we are not 1990 the installed capacity is estimated to be working in the world alone. In the next twenty-Five 1,300,000 MWe of which 80% will be in the Western minutes I will attempt to show you that nuclear World. The breakdown of today's operating power power in Canada has reached the commercial stage, reactors between countries is shown in Table 1, from give you some idea as to what technical areas warrant which you will see that Canada is in fourth place and further work and discuss other reactor concepts based very close to France. on the Canada Deuterium Uranium (CANDU) family of reactors. TABLE 1 - OPERATING NUCLEAR POWER IN THE WORLD EXCLUDING USSR, APRIL 1972 (MWe) USA 9526 UK 6132 France 2278 Canada 2115 Japan 121.3 30000 - W. Germany 906 Switzerland 728 Italy 635 Spain 620 Sweden 472 India 400 20QQO - Pakistan 137 Total 25 m Canada's installed nuclear capacity is estimated to I00OO - grow rapidly over the next 20 years (Fig. 1) reaching 35,000 MWe by 1990. To supply this capacity Canadian utilities will spend $3.5 billion for equip, ment, $1.5 billion to install and house the equipment, and $1.5 billion for heavy water. Annual expenditure 2000 - for the nuclear fuel at that time is estimated to be 1970 about $200 million, which is to be compared 7/ith an estimated $840 million per year if this power were produced from fossil fuel. Figure 1 — Estimated growth of Canada's nuclear This I think is sufficient to show you that Canada power capacity. is in the forefront of nuclear power reactor develop- -1- STEAM TO TURBINE STEAM STEAM/WATER MIXTURE FUEL HEAVY WATER MODERATOR PHW BLW (Pressurized Heavy-Water) (Boiling Light-Water) (Organic-Cooled Roactor) Figure 2 - Schematics of CANDU-PHW, -BLW, and -OCR. TABLEZ-CANDU A FAMILY OF REACTOR CONCEPTS costs {about half that of the USA light-water reactors), the largest amount of power per unit mass of uranium ore of any reactor in the world, and a larger plutonium production rate than any other DISTINGUISHING CHARACTERISTICS thermal reactor, which is why sometimes CANDU is called an advanced converter. What this all means is 1) Heavy-water moderation that the CANDU reactor system is the most efficient supplier and user of neutrons of all reactor systems. Fuel economy — freedom to use natural uranium The materials of construction for the three reactors Spreads out fuel — allows pressure tubes are the same and only in the case of the organic- cooled reactor is the fuel different. Thus our research 2) Pressure tubes of neutron economic material and development program is in the main relevant to Ease of proof testing all three reactor types, which has given us the Ease of scale-up possibility of developing these three types with a Allows evolutionary improvemenls minimum of research and development. 3) Oil-power fuelling OPERATING EXPERIENCE MEMBERS OF FAMILY CHARACTERIZED BY COOLANT Table 3 gives the CANDU power reactors that are either operating or under construction. To give you PHW -• Pressurized heavy-water coolant some feel for the size of this program I would remind BLW - Boiling light-water coolant you that the Canadian share of the St. Lawrence OCR — Organic-cooled reactor Seaway power development is 1000 MWe and that the 1700 MWe of nuclear power now operating in Ontario is about 14% of the Ontario Hydro system. Before doing this, I should first remind you of the CANDU reactor concept and how it can be consi- The Nuclear Power Demonstration (NPD, 25 dered as a family of reactors, each reactor being MWe) reactor came into operation in 1962 and distinguished by the type of coolant used to take the Douglas Point (200 MWe) was committed and heat away from the fuel. Table 2 and Figure 2 show designed before any real experience was obtained the different characteristics of the three reactor from NPD. It is therefore perhaps not surprising that types. The important thing to note is that the Douglas Point ran into some difficulties. However, dominant factor in the CANDU family has always the operation of Douglas Point has not been very been neutron economy, which is reflected in low fuel different from many other prototype nuclear power -2- plants in the world; at least half of the unreliability example, last winter it achieved a capacity factor of was associated with standard power station com- 80%; that is, it produced 80% of the design power ponents such as valves, seals, heat exchangers, output. It is now shut down for maintenance and its turbines, and generators. Although difficulty was heavy water is being used at Pickering. During this experienced with the fueling machines initially, these shutdown a number of major maintenance jobs will difficulties have been overcome and on-power fueling be done including some reblading of the turbines, is now a routine operation. The important points which has accounted for a loss of 8% capacity over learned from Douglas Point were as follows: the last few years. When it starts up again in the fall we expect it to operate as a very reliable source of TABLE is- CANADIAN POWER REACTORS - OPERATING OR UNDER steam, which will be used for heating in the Bruce CONSTRUCTION heavy-water production plant. When the design of the 2000 K,ie Pickering Type MWe Name Start-up station began in 1965 we had three years' experience from NPD but nothing from Douglas Point. However, BHW 22 NPD Rolphlon 1962 sufficient experience had been gained to show how PHW 208 Douglas Point 1967 major improvements could be made. For example, PHW 125 KANUPP 1971 the light-water systems were better segregated from PHW 508 Pickei:is-1 1971 the heavy-water systems, the number of valves and BLW 250 GentiUy 1971 mechanical joints were reduced, and air driers were PHW 508 Pickerlng-2 1971 PHW 203 RAPP-1 1972 included, all of which were expected to lead to lower PHW 508 Pickering-3 1972 heavy-water upkeep costs. The fueling machine had PHW 508 Pickering-4 1973 to be redesigned because the pressure tube size for PHW 203 RAPP-2 1974 Pickering was increased to 4.07 inches from the 3.25 PHW 750 Bruce-1 1976 inches used in NPD and Douglas Point. These may PHW 750 Bmce-2 1977 sound like minor changes to a scientific community, PHW 750 Bruce-3 1978 but in fact are very major when you are confronted PHW 750 Bruce4 1979 with demonstrating high reliability of operation. TABLE 4 - CAPACITY FACTOR FOR PICKERING UNITS 1-3,3 UNITS, EACH 540 MWe 1) the necessity to design reactor buildings for complete recovery of the heavy water that has escaped from the primary heat-transport circuit; 2) to avoid a congested plant layout to provide easier February Critically - - Miy 42 - - Ffcit full po»er maintenance; Miy30 3) to separate heavy-water and light-water circuits to June 42 - - July 91.8 - - ttldeclued avoid downgrading of heavy water escaping from "In Mrvke" the primary heat-transport circuit; August 56.1 - - September B8.B CritlcaUly - 4) to develop improved valves, especially control October 71.8 November 98.8 65.8 - Fint full power valves, to reduce heavy-water leakage; Nov. 7 December 83.2 100.3 - fttdecUred 5) zirconium-clad VO2 fuel is subject fo failure when "taienrice" the power rating is increased after the cladding has 1912 been damaged due to neutron radiation; Juiuary 74.5 80.6 - Februtiy 09.2 78.5 - 6) a more corrosion-resistant material than Monel Hucb 90.B 80.6 - should be used to give lower radiation fields; April 97.6 99.4 Crilkillly M.y Flnt full potnr Hay 12 7) more emphasis should be given to improving the June #3dedind reliability of standard engineering components "unerriai" such as valves, seals, steam generators, turbines, etc.