CODIFICATION OF LMFBR RULES AND COMPARISON OF CODES

Ziel

A complete set of design and construction rules have been drawn up for liquid metal fast breeder reactor (LMFBR) components. The basic features of these Regles de conception et de construction des materials mecaniques des ilots nucleaires, reacteur a neutrons rapid (RCC-MR) rules are:
coherence between low and high temperature rules;
concern for using actual material properties (use of cyclic curves);
concern for being conservative when using simplified assumptions;
concern for simplicity for use by designers by giving detailed rules.

A comparison between RCC-MR, the code case N47 and the Structural Design guide for Class 1 Components of Prototype Fast Breeder Reactor for Elevated Temperature Service referred to as the MONJU code guide has been performed for some items with the following results:
only RCC-MR uses a real complete negligible creep curve;
MONJU guide is strongly concerned with elastic follow up (it is the only code trying to give quantitatives rules);
code case and MONJU guide use the theoretical O'DONNELL POROWSKI diagram to deal with progressive deformation (RCC-MR uses the experimental based efficiency diagram);
large differences exist in the 3 codes for evaluating creep fatigue damage with an elastic analysis;
code case N47 and MONJU guide use fatigue curves with hold time, RCC-MR does not use them;
evaluation of steady stress to compute creep damage is the most pessimistic in RCC-MR (code case N47 sets an upper bound to that stress, and considers that the creep damage due to peak stresses is already taken into account by the use of fatigue curves with hold time and so only membrane and bending stresses are considered for the evaluation of creep damage while the MONJU guide assumes a beneficial residual stress state and calculates separately the damage due to peak stresses);
RCC-MR is the only code to give detailed rules to perform a buckling analysis;
piping rules are similar in RCC-MR and MONJU guide.

Finally the following areas of improvements of RCC-MR have been identified:
creep damage evaluation using an elastic analysis;
rules for a quantitative assessment of elastic follow up;
ratchetting rules for non Bree type problems;
criteria for strong dynamic loadings;
guidelines for inelastic analysis.

Programm/Programme

PRE-NUSAFECS C - Council Resolution of 22 July 1975 on the technological problems of nuclear safety, 1975-

Thema/Themen

Data not available

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

CSC - Cost-sharing contracts

Koordinator

Novatome SA

EU-Beitrag

Keine Daten

Adresse

La Boursière - RN 186
92350 Le Plessis-Robinson
Frankreich

Gesamtkosten