J. BOURN, QSA Global, Stratham, New Hampshire (U.S.)

In the high-stakes world of oil and gas pipelines, verifying the integrity of welds and detecting hidden corrosion is a non-negotiable priority. We often refer to industrial gamma radiography as the "invisible eye" of nondestructive testing (NDT)—a technique that uses ionizing radiation from isotopes like Iridium-192 (Ir-192) or Selenium-75 (Se-75) to peer through steel without causing a single scratch.

However, as the U.S. pipeline market continues to modernize, its focus is shifting. It is no longer just about getting the shot; it is about how managers are evolving the equipment—specifically the gamma radiography projector—to eliminate the age-old risks associated with high-activity sources.

The Achilles' Heel: The Human Element

Despite decades of hardware improvements, the data tells a consistent story: technology rarely fails, but humans do. A 50-yr in-house QSA analysis shows that human error remains the dominant cause of industry incidents.

Common "near-miss" precursors in the field include:

• Skipping the survey: Failing to perform a post-exposure radiation survey is one of the most common causes of serious overexposure.
• Complacency: In the routine of pipeline work, "rushing" or "fatigue" can lead to skipped steps.
• The "untrained hero": Serious injuries often occur during poorly planned "recovery attempts" when a source gets stuck.

In the U.S., local extremity injuries (i.e., burns to the hands and fingers) remain the most frequently documented severe injury, and often result because a technician reached for a device without confirming the source was retracted.

The Heart of the Operation: Rethinking the Projector

The radiography projector is the primary line of defense between a technician and a radioactive source. For decades, these devices have been the "black boxes" of the pipeline right-of-way (ROW), but recent engineering trends are turning them into active safety systems.

Mechanical Failsafes

Modern projectors are moving beyond simple locks to integrated automatic securing mechanisms. These systems are designed to ensure the source is physically locked the moment it retracts into the "S" tube, preventing accidental exposure if a control cable is disconnected prematurely.

The Material Shift

While depleted uranium was historically used for shielding due to its density, U.S. managers are increasingly opting for tungsten-shielded projectors. Tungsten offers comparable radiation attenuation but also removes the regulatory and contamination headaches associated with radioactive shielding materials, simplifying the lifecycle of the equipment.

Visual Confidence

Equipment standards like ISO 3999 and ANSI N432 have driven a move toward clear, standardized visual indicators that tell a technician at a glance whether the source is safely stored or exposed.

Shrinking the Danger Zone: The Rise of SCAR and Se-75

One of the greatest challenges in pipeline NDT is managing the exclusion zone. In a crowded facility or busy ROW, a large controlled area creates production pressure, which often tempts crews to rush—the primary precursor to human error.

To combat this, managers are focusing on:

SCAR

By utilizing specialized projectors and integrated collimators, operators drastically reduce the amount of scattered radiation. This effectively shrinks the danger zone, allowing other pipeline crews to continue their work nearby without risking overexposure.

Alternative Isotopes

The adoption of Se-75 is a gamechanger for specific applications. Because it has lower energy levels than Cobalt-60 or Ir-192, Se-75 allows for smaller controlled areas and lighter-weight projectors, reducing technician fatigue.

The U.S. Regulatory Guardrail: 10 CFR Part 34

In the U.S., these hardware improvements are backed by a rigorous regulatory framework. The Nuclear Regulatory Commission (NRC) and Agreement States mandate strict adherence to 10 CFR Part 34, which encompasses everything from equipment performance to mandatory personnel certification.

Crucially, this regulation emphasizes that for these procedures, the hardware is only as good as the software. Even with the best projector, the post-exposure radiation survey remains the single most critical step in preventing an accident. Managers are now reinforcing this with the mandatory use of alarming rate meters to provide a final, real-time warning if a source fails to retract.

The Future: Digital and Robotic Integration

As we look toward the next decade of pipeline safety, the "projector" may look very different. The industry is currently exploring:

Digital Radiography (DR)

Eliminating the need for film and chemicals, DR improves workflow efficiency and can potentially reduce the time a source needs to be exposed.

Robotic Deployment

Emerging systems and unmanned autonomous vehicles (UAVs) are being used to position projectors or detect radiation levels in hazardous areas, putting more distance between the technician and the source. This represents a fundamental tenet of the "as low as reasonably achievable" (ALARA) principle.

Safe pipeline radiography is no longer just about following a rulebook: it is about an integrated system of reliable technology, clear procedures and a safety-conscious culture. By investing in tungsten-shielded projectors, SCAR technology and digital oversight, pipeline managers are ensuring that the "invisible eye" remains a tool for protection, not a source of peril.

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About the Author

JASON (JAKE) BOURN is the VP and General Manager at QSA Global, a global leader in high-performance radiation sources and NDT equipment. With a career spanning more than 35 yrs in nuclear engineering specialties, Bourn is a recognized leader in the industrial, medical and isotope sectors.

Throughout the last 19 yrs at QSA Global, he and the team have delivered construction of three Ir-192 plants, a Cf-252 plant and an AmBe Plant, and are now developing the world's highest-volume Ra-226 purification plant, which will come online in June. Using customer-driven innovation, he is a patent holder in multiple medical and radiography devices.

As an active member of ASNT, WCNDT and NDTMA, Bourn has provided technical presentations for NDT professionals around the world. He volunteers in the U.S. Small Business Administration as a mentor for entrepreneurs.