Stress corrosion of valves in primary coolant circuit dead legs
- 1. Electricite de France (EDF), 75 - Paris (France)
- 2. Centre National de la Recherche Scientifique, 94 - Vitry-sur-Seine (France). Centre d'Etudes de Chimie Metallurgique
Description
Many cases of corrosion have been observed along lines corresponding to a water/steam interface in valve components and adjacent portions of pipes; they are located in portions of auxiliary circuit, called dead legs, connected to the main primary loops of pressurized water reactors. A pronounced attack of the Stellite coating on the bearing surface is observed, together with cracking in the stainless steel, mostly transgranular. Laboratory investigations were performed, including autoclave tests on U-bend specimens at 250 and 2900C in concentrated boric acid solutions, and constant load tests at boiling point of these solutions. They allowed to reproduce the cracking phenomena, and to confirm the influence of pH, chlorides, and boric acid. The particular thermohydraulic and chemical conditions occurring in the dead legs can explain the cracking cases observed
Abstract (French)
De nombreux cas de corrosion ont ete observes sur des vannes, des clapets ainsi que sur les portions de tubulures adjacentes a ceux-ci, le long de lignes de niveau correspondant a une interface eau-vapeur; ils se produisent dans des portions de circuits auxiliaires du circuit primaire de reacteurs a eau pressurisee, appelees bras morts. Une attaque marquee du revetement en Stellite des surfaces d'etancheite se produit, souvent associee a une fissuration de l'acier inoxydable, generalement transgranulaire. Des etudes en laboratoire ont ete effectuees. Elles ont comporte des essais a deformation imposee en autoclave, dans des solutions concentrees d'acide borique a 250 et 2900C, ainsi que des essais a charge imposee dans ces solutions a ebullition. Elles ont permis de reproduire les phenomenes de fissuration et de confirmer l'influence du pH, des chlorures et de l'acide borique. Les conditions thermohydrauliques et chimiques particulieres rencontrees dans les bras morts peuvent expliquer les cas de fissuration rencontresAdditional details
Additional titles
- Original title (French)
- Corrosion sous contrainte de pieces de robinetterie dans les bras morts du circuit primaire
Publishing Information
- Publisher
- Societe Francaise d'Energie Nucleaire.
- Imprint Place
- Paris (France)
- Imprint Title
- Contribution of Materials Investigation to the Resolution of problems encountered in PWR Plants. Volume 2
- Imprint Pagination
- 305 p.
- Journal Page Range
- p. 547-557.
Conference
- Title
- International Colloquium on Contribution of materials Investigation to the Resolution of Problems Encountered in PWR Plants.
- Original Conference Title
- Colloque International sur la Contribution des Expertises sur materiaux a la resolution des problemes rencontres dans les REP
- Dates
- 10-14 Sep 1990.
- Place
- Fontevraud (France).
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 22083595
- Subject category
- S36: MATERIALS SCIENCE; S21: SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- AUXILIARY SYSTEMS; BENCH-SCALE EXPERIMENTS; PRIMARY COOLANT CIRCUITS; PWR TYPE REACTORS; STEEL-CR17NI12MO3-L; STEEL-CR18NI10; STRESS CORROSION; VALVES
- Descriptors DEC
- ALLOYS; AUSTENITIC STEELS; CARBON ADDITIONS; CHEMICAL REACTIONS; CHROMIUM ALLOYS; CHROMIUM-NICKEL STEELS; CHROMIUM-NICKEL-MOLYBDENUM STE; CONTROL EQUIPMENT; COOLING SYSTEMS; CORROSION; CORROSION RESISTANT ALLOYS; CROLOY; ENRICHED URANIUM REACTORS; EQUIPMENT; FLOW REGULATORS; HEAT RESISTING ALLOYS; HIGH ALLOY STEELS; IRON ALLOYS; IRON BASE ALLOYS; LOW CARBON-HIGH ALLOY STEELS; MOLYBDENUM ALLOYS; NICKEL ALLOYS; POWER REACTORS; REACTOR COMPONENTS; REACTOR COOLING SYSTEMS; REACTORS; STAINLESS STEELS; STEELS; THERMAL REACTORS; WATER COOLED REACTORS; WATER MODERATED REACTORS
Optional Information
- Notes
- Imprint:Contribution des Expertises sur materiaux a la Resolution des problemes rencontres dans les REP. Volume 2.