Bulgaria, Varna, 9-11 June, 2010

Advancing of VVER Reactor Core

Y. Semchenkov, Y. Styrin, Russian Research Centre “” presented by Yury Styrin RussianRussian ResearchResearch CenterCenter ““KurchatovKurchatov InstituteInstitute”” UniqueUnique InterdisciplinaryInterdisciplinary ScientificScientific ComplexComplex ofof WorldWorld LevelLevel

Bulgaria, Varna, 9-11 June, 2010 MainMain FieldsFields ofof ActivitiesActivities

Nuclear arms facilities for the Navy Space nuclear power systems Nuclear power engineering - NPPs with light water power reactors (VVER) - NPPs with channel type graphite reactors of great power (RBMK) - Perspective innovative designing

Thermonuclear fusion Nanotechnology and materials Nuclear technologies for the medicine New information technologies GRID and GLORIAD Rehabilitation of contaminated sites. Materials Control Protection & Accounting (MCP&A) for nuclear arms and nuclear materials

Bulgaria, Varna, 9-11 June, 2010 Institute of Nuclear reactors RRC “Kurchatov Institute”: • Performs scientific advising at designing and ensures following- up the operation of NPPs with VVER reactors • Develops a conception and principles of ensuring nuclear, radiation and ecological safety • Performs elaboration and experimental verification of reactor cores and cycles • Elaborates methods and calculation codes in neutronics, thermohydraulics and dynamics of reactor installations • Performs elaboration of methods, means and systems of core control and diagnostics • Elaborates documentation and assessment of projects

Bulgaria, Varna, 9-11 June, 2010 «Nuclear Renaissance» during 2004-2009 (IAEA Data, Dec. 2009) Start of Construction

Country Number of units / Rated power, MW(el) / LWR units LWR China 21 / 21 20890 / 20890 Korea 5 / 5 5180 / 5180 5 / 4 2984 / 2234 Japan 2 / 2 2191 / 2191 1 / 1 1600 / 1600 France 1 / 1 1600 / 1600 India 1 / 0 470 / 0 Pakistan 1 / 1 300 / 300 Total 37 / 35 35215 / 34165

Bulgaria, Varna, 9-11 June, 2010 Built 69 VVER reactor units, 60 are in operation

Leningrad-2 AES-2006 AES-2006 Novovoronezh-2 First unit AES-92 NPP Kudankulam 2 units AES-91 VVER-1000 2 units Tianwan,China VVER-1000 Great series Zaporizhzhia-1 21 units Small series VVER-1000 5 units NVAES-5 VVER-440 Generation II Loviisa, Finland 19 units Generation I VVER-440 16 units NVAES-3 VVER-365 VVER-70 Reinsberg, East Germany VVER-210

March 2010 – physical start-up of Unit 2 NPP. Preliminary date of commissioning – October 2010. 2010 : Unit 2 Volgodonsk NPP, Unit 1 Kudankulam NPP and Unit 1 Bushehr NPP. Bulgaria, Varna, 9-11 June, 2010 (Water-Water Energy Reactors)

First Unit Number of Number of units VVER-440 / Country Commission built units in operation VVER-1000 Russia 18 16 10 East Germany Bulgaria Armenia Finland Hungary Czech China Iran India

Bulgaria, Varna, 9-11 June, 2010 DevelopmentDevelopment ofof advancedadvanced fuelfuel cyclescycles andand newnew fuelfuel (VVER(VVER--440)440) FA parameter Initial fuel cycle Actual design Perspective design, 2010 Construction Zr (Hf≤0.05%) Zr (Hf≤0.05%) Zr (Hf≤0.01%) material Shroud material Zr (Hf≤0.05%) Zr (Hf≤0.01%) No

Burnable poison - UO2 –Gd2O3 UO2 –Gd2O3

Weight of UO2 in a 1.00 1.05 1.14 fuel element, rel. Central hole 1.00/1.00 0.86/1.02 0.0/1.02 diameter, rel./fuel column height, rel. Pitch of fuel 1.00/1.00 1.01/1.00 1.032/1.00 elements in a cluster, rel./outer fuel element diameter, rel. Maximum allowable 4.40 4.6 4.95 fuel enrichment, % Maximum fuel 53.9 57.5 65 DevelopmentDevelopment ofof AdvancedAdvanced FuelFuel CyclesCycles andand NewNew FuelFuel (VVER(VVER--1000)1000) FA parameter Initial fuel cycle Actual design Perspective design Construction Steel Zr (Hf≤0.05%) Zr (Hf≤0.01%) material

Burnable poison Boron (discrete UO2 + Gd2O3 UO2 + Gd2O3 poisons) Enrichment grading yes yes/no no in FAs

Weight of UO2 in a 1.00 1.08 1.13 FA, rel. Central hole 2.4/3540 1.4/3540 1.2/3690 diameter, mm / (0/3690) fuel column height, mm Maximum 4.40 4.4 4.95 allowable fuel enrichment, % Maximum 49 55 60-65 allowable fuel in a FA, MWd/k Requirements for VVER-1000 Fuel Cycles (consumers in Russia, EUR, tender statements)

9Operation duration between reloadings 12 – 24 months 9Possibility of fuel cycle length variation due to: - change of quantity and enrichment of charged fuel assemblies (FAs), - operation at “stretch out” up to 60 EFPD, - untimely shutdown with 30 EFPD before planned EOC. 9Fuel enrichment not more 5%, FA in cold water without boron shall be subcritical 9FA burnup - now 60 Mwd/kgU - nearest future 70 Mwd/kgU - future up to 100 Mwd/kgU 9Ensuring of negative internal nuclear feedbacks on reactor temperature and power 9Ensuring of necessary (from reactor safety view) worth of mechanical control rods system 9Studies to ensure reactor subcriticality in hot zero state (HZP) without boron in 9Arrangement of core loads with low leakage

Bulgaria, Varna, 9-11 June, 2010 11

FuelFuel AssembliesAssemblies ofof LastLast GenerationGeneration forfor VVERVVER--10001000 andand VVERVVER--12001200 TVS-2 skeleton is formed by tubes linked with TVSA skeleton is formed by corners spacer grids by contact welding linked with spacer grids by contact welding Top nozzle

Top Guide tubes Spa nozzle -cer grid Strengthening Corner Corner Contact Fuel elements welding cluster Spacer grid

Spacer grid

Bottom Bottom nozzle nozzle Contact welding

TVS-2 (OKB «Gidropress») TVSA (OKB «Afrikantov») Implementation of new designs TVSA and TVS-2 reduces a maximum FA distortion in VVER-1000 core to 6-9 mm, a maximum gap – to 7-10 mm Bulgaria, Varna, 9-11 June, 2010 EvolutionEvolution ofof FuelFuel LoadsLoads UsingUsing TVSAsTVSAs (Design(Design ofof OKBOKB Afrikantov)Afrikantov) forfor KalininKalinin NPPNPP UnitUnit 11 Number of max max Num- modifica- max max repeat fuel pin max Load № ber of tions of operation max max Q * criticality CH BO enrich- burnup, EFPD l 3 feeding feeding duration, Кq Kr W/c tempera- ** ment, MWd/kg 3 FAs FAs year m ture, g/kg % °С 21 42 4 4,95 7 62 300 1,33 1,46 288 188 13,3 (2005) 22 42 3 4,95 6 58 317 1,36 1,49 295 192 14,2 (2006) 23 42 1 4,95 6 64 325 1,32 1,51 305 184 14,4 (2007) 24 36 1 4,7 5 66 330 1,40 1,55 310 177 15,3 (2008) 25 37 1 4,7 5 61 316 1,40 1,57 310 192 15,4 (2009) 26 36 1 4,7 6 65 302 1,32 1,56 310 195 15,3 (2010)

* without margin coefficient Bulgaria, Varna, 9-11 June, 2010 ** 5 % subcriticality VVERVVER--10001000 FuelFuel CyclesCycles underunder RealizationRealization Country NPP FA construction Fuel cycle type Russia Balakovo, 1-4 TVS-2 TVS-2M Transfer to 18-month Volgodonsk, 1 cycle at 104% of nominal power Kalinin, 2,3 TVSA (353/7,6/1,2) TVSA (368/7,6/1,2) Kalinin, 1 TVSA (353/7,6/1,2) Transfer to 12-month TVSA (353/7,8/0) 5-year cycle Ukraine Zaporizhzhya TVSA 12-month cycle South Ukraine Feeding with 42 FAs Khmelnitsky Rivne ChezhCzech Temelin Westinghouse Transfer to 12-month TVSA-T 5–year cycle KozloduyKozloduiKozloduy TVSA 12-month cycle Bulgaria Feeding with 42 FAs Plan: transfer to 104%

China Tianwan UTVS ТВС-2М 12- month cycle, Feeding with 48 FAs Plan: transfer to 18-month cycle

Bulgaria, Varna, 9-11 June, 2010 ImplementationImplementation ofof perspectiveperspective cyclescycles forfor VVERVVER-- 10001000 ensuresensures :: ƒ Possibility to arrange fuel loads with operation duration up to 500 EFPD. ƒ Reduction of: – Specific FA consumption by ~ 21-24%, – Specific enriched consumption by ~ 17-20%, – Specific natural uranium consumption by ~ 6-9%. ƒ Reduction of fuel component in power cost by ~ 9-12%. DueDue toto implementationimplementation ofof perspectiveperspective cyclescycles ƒ Average FA burnup increases up to 60 MWd/kg, ƒ Maximum FA burnup increases up to 65 MWd/kg, ƒ Relative powers of FAs and fuel pins increase by 3-6%.

Bulgaria, Varna, 9-11 June, 2010 FuelFuel CyclesCycles ofof VVERVVER--12001200 While designing fuel cycles for VVER-1200 there are applied the technical and construction decisions realized in actual projects of VVER-1000 and verified in test and commercial operations at Kalinin and Balakovo NPPs. Fuel assembly design for VVER-1200 is based on TVS-2M construction developed by Gidropress. From neutronics point of view the design difference of these FAs is following: 9Fuel column height has been increased from 3680 to 3730mm, 9Measurement channel has been moved from FA center to a cell located between rows of guide tubes, 9In the central cell a fuel element has been located. Radial sizes of fuel element cladding (outer diameter 9,1 mm, cladding thickness 0,69 mm) and fuel pellet (pellet diameter 7,6 mm, diameter of axial hole 1,2 mm) are identical to those of VVER-1000 fuel element. Duration of operation between reloadings is 12-18 months at power charge coefficient not less 0,9.

Bulgaria, Varna, 9-11 June, 2010 Fuel CyclesCycles of VVER-1200 (cont.) Negative values of reactivity coefficients on temperature and power are ensured. Fuel enrichment in fuel elements is limited by 4,95 %. Maximum FA burnup does not exceed 70 MWd/kgU Maximum fuel element linear power does not exceed 420 W/cm Maximum fuel element relative power (Kr) is not more 1,57 Uranium-gadolinium fuel with natural isotopic composition is used as a burnable poison. Fraction of gadolinium dioxide in fuel is to be chosen from the interval 3-8 g/cm3 that is accepted now for VVER-1000 reactors. In VVER-1200 in CPS (Control&Protection System) are used combined absorbers identical to those in operating VVER-1000s. Total number of control rods in CPS can reach 121 pcs. While arranging VVER-1200 core the most burnt fuel assemblies are placed at core periphery.

Bulgaria, Varna, 9-11 June, 2010 Examples of Fuel Assembly Pattern for VVER-1200 Tubes for Control Rods

Instrumentation tube Uranium-Gadolinium fuel elements

Bulgaria, Varna, 9-11 June, 2010 First and Equilibrium Fuel Loads of Base 12-month 4-year Cycle of VVER-1200

158 159 160 161 162 163 48.9 48.7 0.0 0.0 48.8 50.8 Z40 Z44B2 Z44B2 Z44B2 Z44B2 Z40 Z48A2 Z48B6 Z49 Z49 Z48B6 Z48A2 158 159 160 161 162 163 158 159 160 161 162 163 149 150 151 152 153 154 155 156 157 50.8 47.0 0.0 0.0 46.9 0.0 0.0 47.0 48.9 Z40 Z33Z9 Z24 Z33Z2 Z24 Z33Z2 Z24 Z33Z9 Z40 Z48A2 Z49 Z48B6 Z48A2 Z49 Z48A2 Z48B6 Z49 Z48A2 149 150 151 152 153 154 155 156 157 149 150 151 152 153 154 155 156 157 139 140 141 142 143 144 145 146 147 148 48.8 0.0 13.5 31.3 34.8 34.7 31.3 13.5 0.0 48.7 Z44B2 Z24 Z24 Z13 Z13 Z13 Z13 Z24 Z24 Z44B2 Z48B6 Z48B6 Z49 Z49 Z48B6 Z48B6 Z49 Z49 Z48B6 Z48B6 139 140 141 142 143 144 145 146 147 148 139 140 141 142 143 144 145 146 147 148 128 129 130 131 132 133 134 135 136 137 138 0.0 0.0 31.3 18.4 16.9 13.5 16.9 18.4 31.3 0.0 0.0 Z44B2 Z33Z2 Z13 Z13 Z33Z9 Z24 Z33Z9 Z13 Z13 Z33Z2 Z44B2 Z49 Z48A2 Z49 Z40D2 Z48B6 Z49 Z48B6 Z40D2 Z49 Z48A2 Z49 128 129 130 131 132 133 134 135 136 137 138 128 129 130 131 132 133 134 135 136 137 138 116 117 118 119 120 121 122 123 124 125 126 127 0.0 46.9 34.7 16.9 18.2 36.0 34.9 18.2 16.9 34.8 46.9 0.0 Z44B2 Z24 Z13 Z33Z9 Z24 Z13 Z13 Z24 Z33Z9 Z13 Z24 Z44B2 Z49 Z49 Z48B6 Z48B6 Z48A2 Z48A2 Z40D2 Z48A2 Z48B6 Z48B6 Z49 Z49 116 117 118 119 120 121 122 123 124 125 126 127 116 117 118 119 120 121 122 123 124 125 126 127 103 104 105 106 107 108 109 110 111 112 113 114 115 48.7 0.0 34.8 13.5 34.9 18.1 0.0 18.1 36.0 13.5 34.7 0.0 48.8 Z44B2 Z33Z2 Z13 Z24 Z13 Z24 Z33Z9 Z24 Z13 Z24 Z13 Z33Z2 Z44B2 Z48B6 Z48A2 Z48B6 Z49 Z40D2 Z48A2 Z40D2 Z48A2 Z48A2 Z49 Z48B6 Z48A2 Z48B6 103 104 105 106 107 108 109 110 111 112 113 114 115 103 104 105 106 107 108 109 110 111 112 113 114 115 89 90 91 92 93 94 95 96 97 98 99 100 101 102 48.9 0.0 31.3 16.9 36.0 0.0 35.7 35.7 0.0 34.9 16.9 31.3 0.0 50.8 Z40 Z24 Z13 Z33Z9 Z13 Z33Z9 Z13 Z13 Z33Z9 Z13 Z33Z9 Z13 Z24 Z40 Z48A2 Z48B6 Z49 Z48B6 Z48A2 Z40D2 Z48A2 Z48A2 Z40D2 Z40D2 Z48B6 Z49 Z48B6 Z48A2 89 90 91 92 93 94 95 96 97 98 99 100 101 102 89 90 91 92 93 94 95 96 97 98 99 100 101 102 76 77 78 79 80 81 82 83 84 85 86 87 88 47.0 13.5 18.4 18.2 18.1 35.7 48.7 35.7 18.1 18.2 18.4 13.5 47.0 Z33Z9 Z24 Z13 Z24 Z24 Z13 Z33Z2 Z13 Z24 Z24 Z13 Z24 Z33Z9 Z49 Z49 Z40D2 Z48A2 Z48A2 Z48A2 Z40D2 Z48A2 Z48A2 Z48A2 Z40D2 Z49 Z49 76 77 78 79 80 81 82 83 84 85 86 87 88 76 77 78 79 80 81 82 83 84 85 86 87 88 62 63 64 65 66 67 68 69 70 71 72 73 74 75 50.8 0.0 31.3 16.9 34.9 0.0 35.7 35.7 0.0 36.0 16.9 31.3 0.0 48.9 Z40 Z24 Z13 Z33Z9 Z13 Z33Z9 Z13 Z13 Z33Z9 Z13 Z33Z9 Z13 Z24 Z40 Z48A2 Z48B6 Z49 Z48B6 Z40D2 Z40D2 Z48A2 Z48A2 Z40D2 Z48A2 Z48B6 Z49 Z48B6 Z48A2 62 63 64 65 66 67 68 69 70 71 72 73 74 75 62 63 64 65 66 67 68 69 70 71 72 73 74 75 49 50 51 52 53 54 55 56 57 58 59 60 61 48.8 0.0 34.7 13.5 36.0 18.1 0.0 18.1 34.9 13.5 34.8 0.0 48.7 Z44B2 Z33Z2 Z13 Z24 Z13 Z24 Z33Z9 Z24 Z13 Z24 Z13 Z33Z2 Z44B2 Z48B6 Z48A2 Z48B6 Z49 Z48A2 Z48A2 Z40D2 Z48A2 Z40D2 Z49 Z48B6 Z48A2 Z48B6 49 50 51 52 53 54 55 56 57 58 59 60 61 49 50 51 52 53 54 55 56 57 58 59 60 61 37 38 39 40 41 42 43 44 45 46 47 48 0.0 46.9 34.8 16.9 18.2 34.9 36.0 18.2 16.9 34.7 46.9 0.0 Z44B2 Z24 Z13 Z33Z9 Z24 Z13 Z13 Z24 Z33Z9 Z13 Z24 Z44B2 Z49 Z49 Z48B6 Z48B6 Z48A2 Z40D2 Z48A2 Z48A2 Z48B6 Z48B6 Z49 Z49 37 38 39 40 41 42 43 44 45 46 47 48 37 38 39 40 41 42 43 44 45 46 47 48 26 27 28 29 30 31 32 33 34 35 36 0.0 0.0 31.3 18.4 16.9 13.5 16.9 18.4 31.3 0.0 0.0 Z44B2 Z33Z2 Z13 Z13 Z33Z9 Z24 Z33Z9 Z13 Z13 Z33Z2 Z44B2 Z49 Z48A2 Z49 Z40D2 Z48B6 Z49 Z48B6 Z40D2 Z49 Z48A2 Z49 26 27 28 29 30 31 32 33 34 35 36 26 27 28 29 30 31 32 33 34 35 36 16 17 18 19 20 21 22 23 24 25 48.7 0.0 13.5 31.3 34.7 34.8 31.3 13.5 0.0 48.8 Z44B2 Z24 Z24 Z13 Z13 Z13 Z13 Z24 Z24 Z44B2 Z48B6 Z48B6 Z49 Z49 Z48B6 Z48B6 Z49 Z49 Z48B6 Z48B6 16 17 18 19 20 21 22 23 24 25 16 17 18 19 20 21 22 23 24 25 7 8 9 10 11 12 13 14 15 48.9 47.0 0.0 0.0 46.9 0.0 0.0 47.0 50.8 Z40 Z33Z9 Z24 Z33Z2 Z24 Z33Z2 Z24 Z33Z9 Z40 Z48A2 Z49 Z48B6 Z48A2 Z49 Z48A2 Z48B6 Z49 Z48A2 7 8 9 10 11 12 13 14 15 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 50.8 48.8 0.0 0.0 48.7 48.9 Z40 Z44B2 Z44B2 Z44B2 Z44B2 Z40 Z48A2 Z48B6 Z49 Z49 Z48B6 Z48A2 1 2 3 4 5 6 1 2 3 4 5 6 Quantity of feeding FAs - 42 pcs Cycle duration – 343 EFPD Cycle duration - 344 EFPD Average enrichment– 2.68% Average enrichment – 4.79%

Bulgaria, Varna, 9-11 June, 2010 Characteristics of Equilibrium Fuel Cycles for VVER-1200

Fuel Cycle Type 12-month 12-month18-month 1 2 Quantity of charged FAs, pcs 42 36 72/73 Average enrichment, % 4,79 4,82 4,70 Cycle duration, EFPD 497 343 310 (510) FA average burnup, MWd/kg 55,5 58,4 48,4 FA maximum burnup, MWd/kg 59,4 64,2 56,4 Maximum relative fuel element power 1,53 1,57 1,50 Reactivity coefficient on coolant temperature (HZP, CR CPS ), pcm/°С -1 -1 -2 Boric Acid concentration (CZP , CR CPS , dρ/ρ = 0.05), g/kg 15,9 15,8 15,9 Repeat criticality temperature, °С 90 <20 40 Reactivity without boron and xenon (HZP, ОР СУЗ ),% +0,9 -4,3 -0,3

Bulgaria, Varna, 9-11 June, 2010 24-month Fuel Cycle (fuel element 7,8/0)

80

, 75 ТВС 70

65 6,5%

U 60 6,2% кг / 5,9% выгружаемых

сут 55 · 5,6% 36 50 5,3% МВт 42 48 5,0% 54,3 45 60 4,7%

выгорание 66,5 72,5 4,4% 78,5 40

35 Среднее 30 250 300 350 400 450 500 550 600 650 700 750 800

Average burnup of discharged FAs, MWd/kg Average burnup of discharged FAs, FuelДлительность cycle duration, кампании, эфф EFPD.сут. Cycle duration ~ 670 EFPD, Average enrichment ~5,7%, average burnup ~58 MWd/kgU

Bulgaria, Varna, 9-11 June, 2010 МОХМОХ FuelFuel inin VVERVVER--12001200 CoreCore Main difference between MOX and Uranium fuel :

9 Decreased worth of mechanical Control and Protection System and boric acid, 9 Increased power peaking factors, 9 Decreased effective fraction of delayed , 9 Structure and thermo-mechanical fuel properties, 9 Increased radioactivity and power generation in fresh and spent fuel.

Five years ago in Russia in cooperation with French, German and American specialists the studies have been performed and the possibility has been demonstrated to use in V-320 type reactors up to 40% MOX fuel fabricated from military . The list of necessary V-320 modifications has been prepared. In particular it has been proposed to increase control rods worth by using absorber elements enriched in B-10.

Bulgaria, Varna, 9-11 June, 2010 МОХМОХ FuelFuel inin VVERVVER--12001200 CoreCore ((cont.cont.))

Actually the strategy of atomic in Russia does not comprise involving of MOX fuel in VVER fuel cycles.

Nevertheless it should be noted the increased number of control rods in VVER-1200 if compared with V-320 reactor. Their maximum quantity can reach 121 pcs. Such design feature of VVER-1200 creates a precondition to use MOX fuel in future.

Bulgaria, Varna, 9-11 June, 2010 ConclusionConclusion

Works, performed recently in Russia on improvement of VVER-1000 nuclear fuel utilization, allowed significant amelioration of fuel cycles characteristics and ensuring of Russian nuclear fuel competitiveness in world market.

Bulgaria, Varna, 9-11 June, 2010 Arrangement of In-core Monitoring System (SVRK) Detectors

Neutron detectors

Fuel pin

In-core instrumentation tube (KNI) located in a FA Bulgaria, Varna, 9-11 June, 2010 Main features of SVRK-M a) suppressed delay of rhodium self-powered detectors for operative power distribution control in a core b) operative and independent control of reactor thermal power on rhodium detector indications c) control, emergency and preventive protection on local parameters d) independent control of FA power on indications of rhodium self-powered detectors and on in- core thermal control data

All equipment and specific SVRK-M software have been developed and fabricated in Russia.

Bulgaria, Varna, 9-11 June, 2010 Assessed and partially realized the Program of power increasing at operating NPPs with VVER-440 and VVER-1000

Real limit of construction operability Realization of the Program on power Reserve on increasing of NPPs with knowledge and technology Allowable operation VVER-1000 is equivalent limit due to safety analysis to commissioning of one reactor unit with 1000 Stage of intensive Stage of realization Stage of technology development of maximum MW power. adaptation potential

Bulgaria, Varna, 9-11 June, 2010 ReducingReducing ofof ConservatismConservatism whilewhile EstimatingEstimating anan AllowableAllowable PowerPower forfor VVERVVER--10001000

Ways of conservatism reducing

a Optimization of fuel loads

b Reducing of conservatism in accident analysis

c Reducing of margin coefficients

As a result, thermal power can be increased by 12%

Bulgaria, Varna, 9-11 June, 2010 Taking account of world experience and having objective to increase an efficiency and to obtain experience feedback on VVER-1000 operation at increased power the Unit 2 of Balakovo NPP was chosen as a reference one for operating at increased power. Now Units 1-3 of Balakovo NPP are in test-commercial operation

Bulgaria, Varna, 9-11 June, 2010 Characteristics of Ammonia-Potassium and Hydrogen- Potassium Regimes of Chemical & Volume Control System Ammonia-potassium regime Hydrogen-potassium regime

ƒ Increased non-regularity of C&V control ƒ Minimization of oxydation radiolysis system functioning while reactor products in HZP state and in manoeuvre operating in manoeuvre regime because regimes at low power levels that leads of interaction between power level, to lowering of circuit contamination by hydrogen and ammonia content in a activated corrosion products; coolant; ƒ Significant reducing of activated ƒ Producing of oxydation radiolysis technological wastes because of refusal products while operating at reduced to use ammonia and a diminished power levels and in HZP state; quantity of involved pitches in coolant cleaning (KBE) and treatment (KBF and ƒ Reducing of exchange capacity in KPF) systems; coolant cleaning filters while potassium removal; ƒ Simplification of C&V control system support during reactor start-up and ƒ Increased producing of activated cooling-down; technological wastes; ƒ Reducing of laboratory control work and ƒ Technological problems in C&V control simplification of involving an automatic system support during reactor start-up control of parameters for C&V control and cooling-down; system of primary circuit. ƒ Difficulties to create an automatic C&V control system. Main Parameters for VVER and PWR

Characteristics and VVER- VVER- EPR AP-1000 parameters 1000 1200 (AREVA) Westinghouse 1. Reactor thermal 3000 3200 4500 3400 power (QT), MW 2. Unit electric 1040 1200 1600 1117 power (Nel), MW (Lo-3) 3. Efficiency as the 0,347 0,375 0,356 0,329 ratioNel / QT 4.Coolant temperature, оС: 289 298 295 278 - at reactor input; 320 329,7 327,2 321 - at reactor output 5.Pressure, MPa: 15,7 16,2 15,0 15,0 -in primary circuit; 6,3 7,0 7,5 5,5 - generated steam Compactness of АР-1000 is ensured by loss in electric power which cost for 60-year reactor operation is equal approximately to the unit cost but the module construction allows to reduce construction duration from 60 to 36 months. High efficiency of EPR is due to increased steam pressure at low coolant temperature that is possible for vertical steam generator construction. Благодаря

Спасибо

Thanks

Bulgaria, Varna, 9-11 June, 2010