AMPP Nuclear Coatings common mistakes
AMPP Nuclear Coatings · Understand the traps and how to avoid them.
Selecting a coating from a generic chemical-resistance chart instead of verifying that the exact coating system is qualified for the nuclear service condition and substrate.
Candidates carry over industrial coating habits and focus on the chemical name rather than the design-basis environment, radiation exposure, decontamination, and accident conditions.
What to do instead
Start from the project approved coating list and qualification evidence; match coating, primer, substrate, service environment, and required nuclear qualification before evaluating generic resistance data.
Treating radiation and decontamination exposure only as worker-safety issues rather than as coating-performance requirements.
The nuclear environment is unfamiliar, so candidates separate radiological controls from coating selection and miss coating degradation or decontamination demands.
What to do instead
Include expected radiation dose, contamination-control chemicals, cleaning agents, and decontamination methods in the coating review, and confirm the qualified system covers those exposures.
Accepting visual surface cleanliness as sufficient and omitting soluble-salt or chloride testing after wet preparation or hydroblasting.
Visual standards are easier to remember, and candidates equate a clean-looking surface with a chemically acceptable surface.
What to do instead
Verify the specified chemical-cleanliness test and acceptance threshold, test at the required frequency, re-rinse or re-prepare if exceeded, and record results before priming.
Applying the wrong surface-preparation degree or standard to a repair area, such as spot cleaning where full removal is required, without defining the repair boundary.
Candidates memorize cleanliness terms but do not connect them to the specification, existing coating condition, substrate, or extent of repair.
What to do instead
Read the project specification for the repair class and extent, mark boundaries, select the correct preparation standard and comparator, and verify the achieved condition before coating.
Mixing coating components by rough volume, skipping induction time, or using a batch beyond its pot life.
Field convenience and production pressure lead candidates to treat mixing as a simple ratio task rather than a controlled material requirement.
What to do instead
Use the manufacturer’s exact mixing ratio, induction period, pot life, and batch records; discard material that exceeds pot life or shows unusable viscosity.
Checking ambient conditions only at the start of application and using air temperature instead of substrate temperature for dew-point decisions.
Candidates remember that dew point matters but forget that substrate temperature, humidity, and conditions must be monitored through application and cure.
What to do instead
Measure substrate temperature and dew point at specified intervals, record readings through the application and early cure period, and stop work when conditions leave the approved window.
Exceeding the manufacturer’s recoat window and then applying the next coat without preparing the previous coat as required.
Candidates focus on dry-to-touch or full cure and overlook the difference between cure for handling and cure for intercoat adhesion.
What to do instead
Track recoat time from application, apply within the stated window, or perform the specified surface preparation and adhesion verification before recoating.
Taking dry-film thickness readings with an uncalibrated gauge, on the wrong probe range, or without correcting for blast profile and substrate effects.
Candidates memorize a thickness number but not the measurement method, gauge verification, or the effect of surface profile on magnetic readings.
What to do instead
Verify gauge calibration and probe selection, follow the specified thickness survey pattern and averaging rules, correct for profile where required, and record readings and calibration checks.
Performing holiday or continuity testing at an arbitrary voltage, on the wrong coating layer, or without confirming the test method and acceptance criteria.
Candidates treat holiday testing as a pass/fail gadget and do not connect voltage, coating thickness, cure, and substrate to the validity of the test.
What to do instead
Confirm the specified test method, voltage setting, coating cure and thickness, and acceptance criteria; verify equipment before use and document the test and any repairs.
Allowing inspection and test records to be completed retroactively or omitting batch, environmental, calibration, and hold-point signoff details.
Production pressure and unfamiliarity with nuclear quality assurance lead candidates to see documentation as paperwork rather than part of acceptance.
What to do instead
Record results contemporaneously, use traceable batch and equipment identifiers, document environmental readings and calibration checks, and obtain required hold-point signoffs before proceeding.