Mixed Deck — All CRI Topics Flashcards

Which welding defect occurs due to improper cooling rates?

Answer: Cracking.

Cracking in welds can often be attributed to improper cooling rates, especially when the metal cools too quickly. Rapid cooling can induce high residual stresses and promote the formation of brittle microstructures, such as martensite, which are highly susceptible to cracking. This is particularly true for hydrogen-induced cracking or solidification cracking.

What condition defines a 'High Radiation Area' under NRC regulations?

Answer: Dose rate exceeds 1 mSv/hr at 30 cm

A High Radiation Area is defined as any area where dose rates can exceed 1 mSv/hr (100 mrem/hr) at 30 cm from the source or surface.

What role does continuous improvement play in digital radiography systems for CRI certified professionals?

Answer: It drives ongoing enhancement of practices, processes, and outcomes through systematic evaluation

Continuous improvement is fundamental to professional practice in digital radiography systems, involving regular evaluation, feedback integration, and process enhancement to maintain high standards.

Which defect occurs when the weld metal does not properly fuse with the base metal?

Answer: Lack of fusion.

Lack of fusion occurs when the molten weld metal fails to properly coalesce and bond with the base metal or with previous weld passes. This creates unbonded areas within the weld joint, significantly reducing the weld's strength and integrity. It is a critical defect that can lead to structural failure.

What is the primary biological effect of concern from low-level, chronic radiation exposure to workers?

Answer: Stochastic effects such as cancer induction

Stochastic effects like cancer induction are the primary concern for chronic low-level occupational exposure, with no threshold dose.

What is the most effective way to measure success in radiation safety & protection within CRI professional practice?

Answer: Use a combination of quantitative metrics, qualitative assessments, and stakeholder feedback aligned with defined objectives

Effective measurement combines multiple data sources — quantitative metrics, qualitative assessments, and stakeholder feedback — all aligned with clearly defined objectives for a comprehensive evaluation.

What characteristic radiographic appearance distinguishes internal corrosion in a pipe from a weld discontinuity?

Answer: Corrosion appears as irregular dark areas or pitting with no sharp edges, not aligned with weld features

Internal corrosion produces irregular, diffuse dark density variations that do not align with the weld geometry and typically show a pitted or channeled pattern.

A pressure vessel radiograph shows a region of lighter density (less exposure) at the edge of the weld near the nozzle junction. What is the most likely cause?

Answer: Increased material thickness at the reinforcement pad reducing radiation transmission

A reinforcement pad or extra material at a nozzle junction increases local thickness, attenuating more radiation and producing a lighter (lower density) area on film.

When two or more indications are separated by less than the length of the longer indication, how should they be evaluated under most code criteria?

Answer: They are treated as a single continuous indication

Most codes require that closely spaced indications separated by less than the longer indication's length be combined and evaluated as one continuous indication.

What is the recommended viewing distance for interpreting radiographic film?

Answer: Approximately arm’s length.

The recommended viewing distance for interpreting radiographic film is approximately arm’s length (typically 12-18 inches or 30-45 cm). This distance allows the interpreter to view the entire image while maintaining sufficient detail perception and minimizing eye strain. It helps in identifying subtle density changes and defect indications.

Which isotope used in industrial radiography emits primarily gamma radiation at 662 keV?

Answer: Cesium-137

Cesium-137 emits gamma radiation at a characteristic energy of 662 keV with a half-life of about 30 years.

Which of the following best describes a key competency required for equipment calibration & maintenance in CRI practice?

Answer: Strong analytical skills combined with effective communication and ethical judgment

CRI professionals working in equipment calibration & maintenance need analytical skills to assess situations, communication skills to convey findings, and ethical judgment to make sound decisions.

Which discontinuity in castings appears radiographically as an irregular, feathery or branching dark area typically at hot spots?

Answer: Shrinkage porosity

Shrinkage porosity forms in castings as metal contracts during solidification, creating an irregular branching dark area on the radiograph at thermal hot spots.

A radiographer is working with an Ir-192 source. What is the approximate half-life of Ir-192?

Answer: 74 days

Iridium-192 has a half-life of approximately 74 days, requiring periodic source replacement.

Which of the following best describes a key competency required for radiation safety & protection in CRI practice?

Answer: Strong analytical skills combined with effective communication and ethical judgment

CRI professionals working in radiation safety & protection need analytical skills to assess situations, communication skills to convey findings, and ethical judgment to make sound decisions.

What is the most effective way to measure success in equipment calibration & maintenance within CRI professional practice?

Answer: Use a combination of quantitative metrics, qualitative assessments, and stakeholder feedback aligned with defined objectives

Effective measurement combines multiple data sources — quantitative metrics, qualitative assessments, and stakeholder feedback — all aligned with clearly defined objectives for a comprehensive evaluation.

Per AWS D1.1, undercut adjacent to a statically loaded groove weld in base metal 1 inch thick is acceptable up to what maximum depth?

Answer: 1/32 inch (0.8 mm)

AWS D1.1 limits undercut depth to 1/32 inch (0.8 mm) for statically loaded structures in base metal 1 inch or greater in thickness.

Cold lap (overlap) in a weld radiograph appears as which characteristic image feature?

Answer: A dark, irregular line along the weld toe with smooth edges

Cold lap appears as a dark irregular line at the weld toe representing unfused metal that has rolled over without bonding.

In radiographic interpretation, an elongated slag inclusion running parallel to the weld axis is best described as which type of discontinuity?

Answer: Wagon tracks

Parallel elongated slag lines flanking the weld root are termed 'wagon tracks' and indicate slag trapped along the root pass interface.

What is the maximum permissible dose rate at 2 meters from a radiography camera while the source is in the shielded (retracted) position?

Answer: 2 mSv/hr

NRC regulations in 10 CFR Part 34 require that cameras not exceed 2 mSv/hr (200 mrem/hr) at 2 meters when the source is in the shielded position.