VUJE , Inc., Okružná 5, 918 64 Trnava, Slovakia; FEI STU, Ilkovičova 3, 81219 Bratislava, Slovakia 1/10

Thorium Fuel Cycle Under Thorium Fuel Cycle Under VVER and PWR ConditionsVVER and PWR Conditions

17th Atomic Energy Research SymposiumYalta, Crimea, Ukraine24-28 September 2007

Juraj BREZA1,2, Petr DAŘÍLEK2, Vladimír NEČAS1

breza@vuje.sk, darilek@vuje.sk, vladimir.necas@stuba.sk

1 VUJE Inc., Okružná 5, 91864 Trnava, Slovakia

2 Slovak University of Technology, Faculty of Electrical Engineering and Information Technology, Ilkovičova 3, 81219 Bratislava, Slovakia

VUJE , Inc., Okružná 5, 918 64 Trnava, Slovakia; FEI STU, Ilkovičova 3, 81219 Bratislava, Slovakia 2/10

CONTENTS

Motivation

Thorium fuel scenario

Results

Conclusions

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Study of thorium fuel cycle and its application on VVER-440 and PWR reactor

Plutonium transmutation under light water reactor conditions

Participation in project RED-IMPACT focused on advanced fuel cycles

MOTIVATION

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Enriched U

UOXFabrication

VVER-440(UOX core)

STORAGE

FinalDisposal

4.2 wt% U-235

UOX Open fuel cycle

SCENARIOS

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Pu-Th MOX fuel cycle (VVER-440)

Enriched U

UOXFabrication

VVER-440(UOX core)

STORAGE

Waste

4.2 wt% U-235

PuThOXFabrication

VVER-440(PuThOX core) Reprocessing

URT

UOX

Pu - all isotopes

PuThOX

ThOX

FPMA0.1% Pu0.1% U

U

9.74 wt% Pu (5.40 wt% Pu-239)

1.24 wt% Pu

SCENARIOS

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Model of VVER-440 assembly Model of PWR assembly

COMPUTATION MODELS

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target burnup:50 GWd/tHM

core cycle:320 days, 5 years

UOX PuThOX UOX PuThOXU-235 input rate (%) 4.20 0.00 4.20 0.00Pu in spent fuel (%) 1.24 - 1.11 -Pu input rate (%) 0.00 9.74 0.00 8.00Pu-239 input rate (%) 0.00 5.40 0.00 4.05

VVER-440 PWR

INPUT DATA

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

0 10 20 30 40 50Burnup [GWd/tHM]

Mu

ltip

licat

ion

fac

tor

1.23% Pu 1.85% Pu

2.47% Pu 3.71% Pu

4.94% Pu 6.18% Pu

7.41% Pu 8.65% Pu

UOX OFC 9.74% Pu

0.6

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

0 10 20 30 40 50Burnup [GWd/tHM]

Mu

ltip

lic

ati

on

fa

cto

r

1.13% Pu 2.26% Pu

3.40% Pu 4.53% Pu

6.79% Pu 9.06% Pu

UOX OFC 8.00% Pu

Pu content estimation for VVER-440 thorium cycle

Pu content estimation for PWR thorium cycle

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RESULTS

VVER-440 PWR UOX PuThOX UOX PuThOX Pu initial (kg/tHM) 0 97.38 0 80.00 Pu in spent fuel after 5y cooling (kg/tHM) 12.37 51.39 11.06 33.77 MA in spent fuel after 5y cooling (kg/tHM) 1.48 6.15 1.36 5.15 Pu transmutation rate (%) 0 47.22 0 57.80 Pu transmutation rate (kg/tHM) 0 45.98 0 46.23 Rate of Pu and MA in the fuel entering reactors (%)

0 9.74 0 8.00

Rate of Pu and MA in the spent fuel, after 5-years cooling (%)

1.38 5.75 1.24 3.89

Amount of separated Pu (kg/TWhe) 0 24.57 0 - Pu transmutation rate (kg/TWhe) 0 11.60 0 - Total amount of disposed Pu (kg/TWhe) 26.02 12.97 - -

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Both investigated reactors fully loaded with thorium-plutonium fuel can transmute about 46 kg of Pu/tHM but PWR has a better efficiency

Introduction of an advanced fuel cycle in light water reactors does not solve the problem of plutonium burning; it only allows producing less of plutonium than it is produced today with classical UOX fuel

In the case of non-equilibrium cycles, where plutonium will be obtained from the stock of spent fuel, thorium fuel allows to burn Pu into approx. 50% of today store

CONCLUSIONS

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Thank you for your attention