AMPP Nuclear Coatings key terms

A postulated accident condition that a nuclear facility must withstand without losing required safety functions; coatings in safety-related areas are evaluated under these conditions.

An accident in which reactor coolant piping or components fail and coolant escapes; it can expose containment coatings to steam, water jets, and chemical spray.

A coating applied in safety-related nuclear areas where it must remain functional during a design basis accident and not create debris that blocks emergency cooling.

A safety-related coating not exposed to design basis accident conditions; it must perform under normal and abnormal service without compromising safety-related equipment.

A non-safety-related coating in a nuclear plant; it receives no nuclear safety qualification but still must meet specified performance, application, and quality requirements.

The ability of a cured coating to resist degradation from ionizing radiation exposure without cracking, blistering, or losing protective and decontamination properties.

The ease with which radioactive contamination can be removed from a coating surface without damaging the film or spreading contamination.

A radiation protection principle meaning radiation doses are kept as low as reasonably achievable, considering economic, operational, and social factors.

The metallic or concrete pressure boundary of a reactor containment; its coating protects the substrate from corrosion and supports decontamination.

Particles, flakes, or coating fragments that could accumulate on emergency core cooling sump screens and reduce flow during an accident.

Contact with containment spray solutions, often containing boric acid and other chemicals, that can attack coatings during accident or testing conditions.

Coating exposure to continuous or repeated liquid contact, such as in tanks, sumps, or flooded areas, requiring low permeability and chemical resistance.

Repeated heating and cooling that causes coating and substrate to expand and contract differently, potentially leading to cracking or loss of adhesion.

Ionic contaminants such as chlorides and sulfates on a surface that can draw moisture and cause coating blistering or underfilm corrosion.

A field method for extracting soluble salts from a surface with a patch and measuring the solution's conductivity to estimate contamination.

The microscopic surface roughness, or anchor pattern, created on a substrate by abrasive blasting; it improves coating adhesion by mechanical keying.

An abrasive blast cleaning degree that removes nearly all rust, mill scale, and coating, leaving only light staining; commonly specified for nuclear immersion coatings.

An abrasive blast cleaning degree that removes most rust, scale, and coating but allows tightly adherent residues and staining.

Removal of oil, grease, dirt, and loose contaminants with solvents or cleaners before blasting or coating to prevent surface contamination.

Presence of chloride ions on a substrate or in a coating system; it promotes corrosion and blistering and is limited by nuclear specifications.

The temperature at which air becomes saturated and condensation forms; coating application requires the surface temperature to stay safely above the dew point.

A brush-applied extra coat on edges, welds, corners, and other hard-to-coat areas to ensure adequate film thickness before full coating.

The thickness of a coating immediately after application, measured before curing; it is used to estimate the final dry film thickness.

The thickness of the cured coating measured after drying or curing; it is compared with specification limits for each coat and system.

The allowed time between applying successive coats of a coating system; exceeding it may require surface roughening to restore adhesion.

The usable time after mixing a multicomponent coating during which it remains suitable for application before viscosity or reactivity changes make it unacceptable.

A surface film or oily residue on amine-cured epoxy caused by moisture or carbon dioxide reaction; it can impair adhesion between coats.

A non-destructive test that applies electrical voltage across a coating to find pinholes, thin spots, or discontinuities in the film.

A test in which a dolly is bonded to a coating, pulled normal to the surface, and the stress at failure is recorded.

A project-specific document that defines quality controls, responsibilities, inspection activities, and acceptance criteria for coating work, including how nonconformances are handled.

A structured plan listing inspection and test activities, their sequence, acceptance criteria, and hold or witness points for coating work.

A formal record of a condition that does not meet specified requirements, used to document, evaluate, and correct the deficiency.

A stage in coating work where application or inspection cannot proceed until the authorized inspector has reviewed and documented acceptance.

A signed statement from a supplier or contractor certifying that materials or work meet specified requirements, often supported by test records.

A document reporting the chemical composition and mechanical properties of a material batch, used to verify product conformance and traceability.

Application of the coating system to a representative test assembly under job conditions to verify procedures, materials, and applicator performance before production work.

The comparison of an instrument's readings with a known standard to confirm accuracy within specified limits before inspection measurements are accepted.