Structural Integrity Assessment and Lifetime Prediction for the Inermediate Rod Bayonets of Control and Protection Systems of the WWER-440 Reactor: Part 3. Optimization of Post-Irradiation Recovery Annealing of the Inermediate Rod Bayonets

The post-irradiation recovery annealing of grade 14Kh17N2 steel used in the intermediate control bayonets of WWER reactors is optimized. It is shown that the proposed heat treatment conditions completely recover the mechanical properties of the bayonet metal embrittled under neutron irradiation. That said, the chosen conditions do not reduce the corrosion resistance of the intermediate rod pipe made of grade 08Kh18N10T austenitic steel.