Write a risk assessment for The project involves carrying out above- and below-water RT testing on one of the pipe welds on the offshore platform, bearing in mind that there are shift personnel on the platform (the matrix must comply with EGPC 6×6).

For above-water and subsea RT of a pipe weld on an offshore platform, the task should be treated as a high-risk simultaneous operation requiring a formal task-specific risk assessment, radiography procedure, permit to work, and strict coordination with offshore operations, marine, and diving controls. The main hazards are uncontrolled ionizing radiation exposure to radiographers, shift personnel, divers, and vessel crews; unauthorized entry into the radiation area; dropped objects and work-at-height hazards above water; drowning and hypothermia risks; vessel or skiff transfer hazards; subsea entanglement, current, and loss-of-life-support hazards for divers; and failures in communication or emergency response. A competent person should periodically conduct and review a task-specific risk assessment for work over or near water, identifying hazards such as drowning and equipment overturning into water. Radiation work must be under a designated radiation safety officer who establishes operating and emergency procedures, ensures exposures are kept as low as reasonably achievable, verifies surveys are performed and documented, and can terminate operations if unsafe conditions exist. [1] [1] [1] [1] [4]

Hazard identification and typical EGPC 6×6-style risk assessment approach:

• Ionizing radiation from the exposure device or X-ray set: credible consequences include fatal or serious overexposure if personnel or divers enter the beam or source-controlled area; initial risk is typically extreme/intolerable until engineered and administrative controls are in place.
• Simultaneous operations with shift personnel present: routine platform movement, adjacent maintenance, crane operations, hot work, scaffolding, and vessel traffic can lead to inadvertent entry into the controlled area or disruption of barriers and communications.
• Above-water offshore hazards: work at height, dropped objects, slippery decks, poor lighting, weather, wind, wave motion, and overboard risk.
• Subsea hazards: diver entanglement, current, poor visibility, umbilical damage, hazardous mechanisms or pipe intakes, loss of communications, and inability to rapidly evacuate the diver from the radiation field.
• Marine hazards: transfer by boat, skiff, or barge; collision or drift into exclusion zones; man-overboard; cold-water exposure; and rescue delay.
• Confined or poorly ventilated adjacent spaces, if applicable: oxygen deficiency, flammable atmosphere, hydrogen sulfide, and restricted rescue access.
• Human factors: night shift fatigue, miscommunication between radiography crew, control room, marine control, and dive supervisor, and failure to maintain surveillance.
• Emergency scenarios: source fails to retract, X-ray fails to terminate, barrier breach, diver distress, man overboard, weather deterioration, or medical emergency during exclusion.

Using an EGPC 6×6 matrix, assess each hazard by severity x likelihood before controls and after controls. For radiation exposure to uninvolved personnel or divers, the inherent risk should normally be considered at the highest level because a single control failure can cause severe injury. The job should proceed only when residual risk is reduced to the organization’s acceptable level through layered controls: elimination of unnecessary personnel, isolation of the area, time-distance-shielding, verified communications, competent supervision, and emergency readiness. If residual risk remains high because the platform cannot be cleared, the dive spread cannot be isolated, or exclusion cannot be guaranteed, the RT should be postponed or an alternative NDT method considered. [1] [1]

Controlled area, exclusion zone, and radiation protection controls:

• Establish a controlled area based on a pre-job radiation survey or calculated dose-rate boundary for the specific source strength, exposure geometry, deck layout, splash zone, and subsea geometry. The boundary must prevent any unauthorized person from entering a high-radiation area.
• Post radiation warning signs at all access points and along any pathway leading to the area, including temporary barriers.
• Maintain constant surveillance of the temporary job site and take immediate action to prevent unauthorized entry.
• Use physical barriers, barricade tape, hard barriers where practicable, access control, and dedicated sentries at all approach routes, ladders, stair towers, boat landings, and subsea access points.
• For subsea RT, define both a surface exclusion zone and an underwater exclusion zone. No diver should be in the water within the radiation exclusion zone during exposure unless the approved technique specifically demonstrates zero credible exposure to the diver and is accepted by the radiation safety officer and dive supervisor; as a conservative best practice, suspend diving during exposures.
• Coordinate with marine control so that standby vessels, workboats, and crane barges remain outside the exclusion zone during exposure windows.
• Apply ALARA: minimize exposure time, maximize distance, use shielding where feasible, collimate the beam, orient the beam away from occupied areas, and use remote exposure devices and remote monitoring.
• Perform and document radiation surveys before first exposure, after any setup change, and after completion to confirm the source is shielded or the X-ray beam is off before re-entry.

[1] [1] [1] Personnel monitoring, competency, and supervision:

• All radiography personnel should wear assigned personal dosimetry during operations. At temporary job sites, use both passive dosimetry and a direct-reading dosimeter or electronic personal dosimeter.
• Recharge or function-check direct-reading dosimeters at the start of the shift, read them daily, and record exposures.
• If a direct-reading dosimeter is off-scale or reads above its range, stop the person from further radiation work until exposure is evaluated.
• Only trained, authorized radiographers and assistants should conduct the work, under the oversight of the radiation safety officer.
• Use a pre-job toolbox talk covering radiation boundaries, SIMOPS restrictions, emergency signals, source recovery actions, marine hazards, and stop-work authority for all affected departments, including operations, marine, and diving teams.

[1] [1] [1] [1] Permit to work and SIMOPS requirements:

• Issue a dedicated radiography permit to work linked to the offshore SIMOPS plan, shift handover, and area authority approval.
• The permit should define exact location, source or X-ray unit details, exposure times, exclusion boundaries, affected decks and compartments, adjacent work restrictions, communication channels, emergency contacts, and permit validity period.
• Suspend or prohibit incompatible simultaneous operations within or near the exclusion zone, such as diving, over-side work, crane lifts through the boundary, hot work that interferes with barriers, and non-essential personnel movement.
• If the RT location is in or adjacent to a confined or enclosed space, attach the relevant confined space or hot work permit and verify atmospheric testing, ventilation, isolation, standby arrangements, and rescue planning before entry.
• If work is interrupted, conditions change, alarms activate, weather deteriorates, or the boundary cannot be maintained, stop work and revalidate the permit and risk assessment before resuming.

[3] [3] [6] [7] Emergency response expectations:

• Prepare a written radiography emergency plan at the worksite covering source stuck out, damaged source assembly, loss of shielding, accidental exposure, barrier breach, medical emergency, man overboard, and diver emergency.
• The radiation safety officer or designated competent person should control source recovery actions; non-essential personnel must remain outside the exclusion zone until the area is surveyed and declared safe.
• Emergency communications must be tested before the job between radiography crew, area authority, control room, marine control, and dive supervisor.
• For any accidental exposure indication, isolate the area, account for personnel, secure dosimeters, obtain urgent dose assessment, and arrange medical evaluation.
• For confined or enclosed-space interfaces, rescue procedures must be written and available at the job site, with standby personnel and communications maintained.
• For diving interfaces, ensure rescue-capable dive team members and equipment are present when exceptional hazards exist.

[1] [3] [3] [7] [5] Marine and diving safety controls for subsea RT:

• Treat subsea RT as a combined radiation and diving SIMOPS activity requiring joint authorization by the radiation safety officer, offshore installation manager or area authority, marine control, and diving supervisor.
• Before diving near any pipe intake, tunnel, duct, or similar installation, stop flow, lock out the intake mechanism, and do not restart until the diver is clear of the water.
• Where divers approach hazardous mechanisms or intakes, use surface-tethered or surface-supplied diving equipment with effective two-way voice communication, as applicable.
• If contamination is possible subsea, prepare an operational plan identifying contaminants, exclusion zones, contamination reduction measures, PPE, first aid measures, and emergency contacts.
• For over-water work, provide approved flotation where there is drowning risk, inspect flotation devices before use, and have ring buoys and rescue craft immediately available.
• Control vessel movements and personnel transfers during exposure windows; no boat should enter the marine exclusion zone without authorization.

[5] [5] [5] [4] [4] [4] If the RT setup involves enclosed spaces, caissons, flooded cells, or other restricted access areas, add these controls:

• Survey the surrounding area for drifting vapors or connected-space hazards before entry.
• Use a trained supervisor and direct-reading gas monitor for pre-entry testing and continuous monitoring where required.
• Verify isolation, lockout/tagout, ventilation, communications, standby person, rescue equipment, and permit validity before entry.
• If atmospheric conditions change adversely, entrants must exit and the permit must be reissued after reassessment.

[2] [2] [9] [9] [8] A practical residual-risk decision for offshore RT is: do not expose while uninvolved personnel remain inside the verified radiation boundary, while divers are in the water within the affected subsea zone, or while marine traffic can breach the exclusion zone. Compliance should be demonstrated through a documented risk assessment using the EGPC 6×6 matrix, a signed permit to work, radiation survey records, dosimetry records, barrier and signage plan, SIMOPS coordination record, toolbox talk attendance, and emergency arrangements. This aligns with offshore HSE expectations and the cited radiation safety requirements for signage, surveillance, dosimetry, supervision, emergency procedures, and safe conduct of industrial radiography. [1] [1] [1] [1]