Protect nuclear plant fasteners from boric acid corrosion

• Published in: Power engineering (Barrington, Ill.) Vol. 96; no. 3; pp. 38 - 41
• Main Authors: MOISIDIS, N, POPESCU, M, RATIU, M
• Format: Magazine Article
• Language: English
• Published: Tulsa, OK PennWell 01.03.1992; PennWell Publishing Corp; Clarion Events, Ltd
• Subjects: 210200 > Power Reactors, Nonbreeding, Light-Water Moderated, Nonboiling Water Cooled; 220504 > Nuclear Reactor Technology > Environmental Aspects > Design Basis & Hypothetical Accidents > (1992-); 360105 > Metals & Alloys > Corrosion & Erosion; Acid resistance; Acids; ALLOYS; Applied sciences; Boilers; Bolted joints; BORIC ACID; BORON COMPOUNDS; Carbon steel; Chemical attack; Connectors (structural); CONTROL EQUIPMENT; Coolants; Corrosion; CORROSION PROTECTION; Corrosion rate; Corrosion resistance; Corrosion resistant alloys; Corrosion resistant materials; Corrosion resistant steels; CORROSIVE EFFECTS; Criteria; Energy; Energy. Thermal use of fuels; ENRICHED URANIUM REACTORS; Exact sciences and technology; Exposure; FASTENERS; Fission nuclear power plants; FLOW REGULATORS; GENERAL STUDIES OF NUCLEAR REACTORS; HYDROGEN COMPOUNDS; IN-SERVICE INSPECTION; INORGANIC ACIDS; INSPECTION; Installation; Installations for energy generation and conversion: thermal and electrical energy; IRON ALLOYS; Iron and steel plants; IRON BASE ALLOYS; Leakage; Low alloy steels; MAINTENANCE; Maintenance and repair; MATERIALS SCIENCE; Materials selection; MATERIALS TESTING; Methods; Nuclear power generation; Nuclear power plants; OXYGEN COMPOUNDS; Physiological aspects; Power plants; POWER REACTORS; Pressurized water reactors; Protection; Protection and preservation; PUMPS; PWR TYPE REACTORS; Radiation; REACTOR COMPONENTS; REACTORS; SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; Stainless steel; Steel corrosion; STEELS; Stress corrosion cracking; Temperature; TESTING; Thermal cycling; THERMAL REACTORS; VALVES; WATER COOLED REACTORS; WATER MODERATED REACTORS 220400 > Nuclear Reactor Technology > Control Systems; United States > US; Austenitic stainless steel; Sluice; Precipitation hardening alloy; Mechanical properties; Bolt; Fastener; Nut; Corrosion protection; Nuclear reactor; Corrosion resistance; Martensitic stainless steel; Boric acid; Nickel Alloys; Pressurized water reactor
• ISSN: 0032-5961

Boric acid corrosion of pump and valve fasteners in pressurized water reactor (PWR) power plants can be prevented by implementing appropriate fastener steel replacement and extended inspections to detect and correct the cause of leakage. A three-phase corrosion protection program based on system operability, outage-related accessibility, and cost of fastener replacement versus maintenance frequency is presented. Selection criteria for fastener material are also presented. Because of the configuration of the bolted connections, leakage at some closures is inevitable in long-term service. Therefore the replacement of carbon or low-alloy steel fasteners exposed to boric acid corrosion from leaking borated coolant with alternate material resistant to corrosion is desirable.