Areva NP has completed the first use of an "innovative new maintenance technique". The company has used cavitation peening on the reactor vessel closure head of unit 2 of Exelon’s Byron NPP in Illinois. Cavitation peening involves the use of ultra-high-pressure water jets to compress the component’s internal surface, preventing stress corrosion cracking. Areva said the technique is designed to extend the life of nuclear reactor primary circuit components for 20 years and can be used on all reactor designs. Areva said it will also provide cavitation peening services at Byron unit 1 as well as units 1 and 2 of Exelon’s Braidwood plant.