1 RRC KI Reduced leakage 17th Symposium of AER on VVER Reactor Physics and Reactor Safety September 24-29, 2007, Yalta, Crimea, Ukraine ADVANCED FUEL CYCLES FOR VVER-1000 REACTORS Semchenkov Y.M., Pavlovichev A.M., Pavlov V.I., Spirkin E.I., Styrin Y.A. and Kosourov E.K. RRC “Kurchatov Institute” Moscow, Russia

2 Introduction RRC KI Reduced leakage In the present report following themes are discussed: Stages of development of the Russian uranium fuel from the point of view of increase of safety and profitability of fuel loadings operation Neutron-physical and economic characteristics of present-day and perspective uranium fuel cycles Potential of uranium-plutonium regenerate use in VVER-1000 reactors Potential of weapon-grade plutonium disposition in VVER reactors

RRC KI 3 Evolution of VVER-1000 fuel cycles

4 RRC KI Reduced leakage Average burnup versus number of loaded FAs, FA enrichment and cycle length

5 RRC KI Reduced leakage Natural uranium consumption versus number of loaded FAs, FA enrichment and cycle length

6 RRC KI Reduced leakage Cost of electricity generation versus number of loaded FAs, FA enrichment and cycle length (cost of fuel-20%, reloading – 65 days)

7 RRC KI Reduced leakage Cost of electricity generation versus number of loaded FAs, FA enrichment and cycle length (cost of fuel-30%, reloading – 65 days)

8 RRC KI Reduced leakage Cost of electricity generation versus number of loaded FAs, FA enrichment and cycle length (cost of fuel-20%, reloading – 40 days)

9 RRC KI Reduced leakage Average burnup versus number of loaded FAs, FA enrichment and cycle length

10 RRC KI Reduced leakage Loading patterns of Loading patterns of advanced equilibrium cycles Height of core – 3680 mm, fuel pellet diameter -7,6 mm, central hole - 1,2 mm 12-month cycle (36 FAs) Average enrichment – 4,83% Cycle length – 324 EFPD FA operational time – 4 or 5 cycles 18-month cycle (60 FAs) Average enrichment – 4,88% Cycle length – 478 EFPD FA operational time – 2 or 3 cycles

RRC KI 11 Main neutronic characteristics of advanced equilibrium cycles 11

12 Uranium-plutonium regenerate in VVER-1000 RRC KI Reduced leakage It was proposed to use uranium-plutonium regenerate in thermal reactors by using spent fuel of these reactors cleaned from other actinides and fission products, and by following mixing of cleaned fuel with enriched uranium Weight fraction of uranium-plutonium regenerate and highly enriched uranium at their mixing is 0,8 and 0,2 correspondingly Enrichment of highly enriched uranium has been defined from a set of calculations under condition that the equilibrium cycle of VVER-1000 with feed by 42 fresh FAs has the same cycle length as the design uranium cycle. The enrichment of highly enriched uranium for uranium-plutonium fuel was 17,1%

13 Isotopic content of regenerated fuel (kg/tHM) RRC KI Reduced leakage

14 Main neutronic characteristics of equilibrium cycles with regenerated uranium-plutonium fuel RRC KI Reduced leakage

15 Weapon Plutonium MOX FA in VVER-1000 core RRC KI Low leakage Reduced leakage Fuel rod with high plutonium content Fuel rod with medium plutonium content Fuel rod with low plutonium content UGBA rod Guide tube Instrumental tube Preliminary researches with participation of US, French and German experts have shown possibility of use of W-МОХ fuel in existing VVER The pattern of the typical MOX FA

16 Loading patterns of equilibrium cycles with MOX FAs RRC KI Reduced leakage MOX FAs- 30, UOX FAs-24 MOX FAs- 36, UOX FAs EFPD 465 EFPD 684 UGBA 1188 UGBA

17 Main characteristics of equilibrium cycles with MOX fuel RRC KI Reduced leakage * CR CPS boron is enriched by the isotope boron-10 up to 80%

18 Conclusion RRC KI Reduced leakage Advanced uranium fuel cycles for VVER-1000 ensure under meeting safety requirements: effective use of natural uranium; possibility of cycle length variation in a wide interval and consequently possibility of NPP power production adaptation to demands of power net and to eventual changes in relations between components of electricity generation cost; reducing of neutron fluence on reactor vessel in view of its service life prolongation. Expanding of fuel raw material nomenclature is possible for VVER by using regenerated uranium and uranium-plutonium fuel. VVER-1000 reactors could ensure a high rate of weapon-grade plutonium disposition at effective using of plutonium power potential.