UTILIZATION OF THE FRAPCON CODE IN BRAZIL FOR REGULATORIES MATTERS Brazilian Nuclear Energy CommisionBrazilian Nuclear Energy Commision Auro Pontedeiro Daniel Palma Nilo Silva

GUIDELINE OF THE PRESENTATIONGUIDELINE OF THE PRESENTATION Previous users; Technical collaboration with European Union - INSC Project BR3.01/09 (BR/RA/01) ; Types of fuel rods in Brazil; Some basic research.

FUEL ROD PERFORMANCE IN BRAZIL – 80 ’

THE FRAPCON 3.4 USED BY CNEN – 2012THE FRAPCON 3.4 USED BY CNEN – 2012

THE SCOPE OF COLLABORATION: TASK 6 - FUEL ROD PERFORMANCE The objective of this task is to: establish a sustainable capacity within CNEN to carry out independent safety assessments calculation of fuel performance as part of the licensing process; obtain the license of codes to model, in steady state, high burnup fuel (e.g., 70 GWD/MTU) and advanced cladding materials (e.g., ZIRLO and M5).

THE PROBLEM PROPOSEDTHE PROBLEM PROPOSED In the last meeting was proposed a standard problem about a fuel rod typically used in Brazil to be independently model by Germany, French and Brazil. The GRS has provided the power historie and the axial power profile where 5 Cases have been defined. Each benchmark case consists of a 3 cycle load follow operation and the duration of each cycle is 300 days. The cycles are separated by 30 days reload operation and 16 axial power profiles are distinguished. The 16 axial power profiles are kept constant for all benchmark cases defined.

THE PROBLEM PROPOSEDTHE PROBLEM PROPOSED

THE POWER HISTORYTHE POWER HISTORY In all cases, there is a range of thirty days zero power between periods of full power operation. Case 1: 300, 200, 400 W/cm Case 2: 400, 200, 300 W/cm Case 3: 300, 300, 300 W/cm Caso 4: 400, 200, 400 W/cm Caso 5: 200, 400, 200 W/cm

TYPES OF FUEL RODS IN BRAZIL – SIMULATION USING FRAPCON 16 NGF – New Generation Fuel – Zirlo; 16 STD – Standard Fuel – Zirlo HTP – I – High Temperature and Pressure – M5 ANGRA MWANGRA MW

TYPES OF FUEL RODS IN BRAZIL – SIMULATION USING FRAPCON For simplicity, the fuel rods analyzed in all cases has the same linear heat generation rate (q max ´ ) is considered q max ´ = W/m; 363 days of full operation has been considered; A cossenoidal form for the axial power profile was considered – FA (FRAPCON variable) =

COMPARISON BETWEEN THE FUEL RODS - SAFETY ASPECTS

UNCERTAINTIES ANALYSIS – HTP – I (HIGH TEMPERATURE AND PRESSURE – M5)

SENSITIVITY COEFFICIENT FOR EACH VARIABLE AND TYPE OF FUEL ROD)

TESTING NEW CORRELATIONS AND MODELS FOR THERMAL PROPERTIES OF THE UO 2 TESTING NEW CORRELATIONS AND MODELS FOR THERMAL PROPERTIES OF THE UO 2 17 The model proposed by Dias calculates the UO 2 thermal conductivity using the following expression: where T is the temperature in the region of the fuel pellet, expressed in Kelvin, and the porosity effect correlations valid for are below:

THANK YOU FOR YOUR ATTENTION !THANK YOU FOR YOUR ATTENTION !