What Is Radiation Measurement on Ships and Why Is It Carried Out?
Radiation measurement is a technical measurement and analysis process carried out to determine the presence, type and concentration of ionising radiation on ships, in shipyards and at ship recycling facilities. The primary objective is to identify and bring under control the risks that radiation poses to human health, the environment and structural safety.
In the maritime sector, radiation measurement arises in several different contexts:
1. Ship recycling and dismantling: Tankers that have carried oil and gas products in particular can accumulate NORM (Naturally Occurring Radioactive Material) in their pipework and tanks over many years of service. Detecting these deposits is mandatory prior to ship dismantling.
2. Scrap cargo screening: Scrap metal passing through ports may contain lost or abandoned radioactive sources. This threatens both port security and shipyard workers.
3. IHM (Inventory of Hazardous Materials) requirement: Under the EU Ship Recycling Regulation (EU SRR), the requirement for ships of 500 GT and above to carry an approved Inventory of Hazardous Materials also covers radiation analysis.
4. Port State Control (PSC) inspections: During international port inspections, radiation non-conformities lead to serious sanctions.
Why Is Radiation Measurement Vitally Important for Scrap Cargoes?
The scrap metal trade is one of the highest-risk areas worldwide from a radiation safety standpoint. The main reason is that radioactive sources previously used in various industrial and medical applications are, from time to time, transported from country to country hidden within scrap metal.
These sources may originate from applications such as:
- Devices used for well logging in the oil and gas sector
- Industrial radiography equipment
- Old medical devices (radiotherapy equipment)
- Legacy industrial measurement systems
Such sources can travel undetected within scrap from one country to a shipyard, and from there all the way to a steel production facility — and the number of people exposed along the way can run into the tens or even hundreds.
Türkiye is a significant player in global scrap metal imports. Under the Communiqué on Import Inspection of Scrap Metal Subject to Control for Environmental Protection (2026/23), scrap metal importers are required to install radiation measurement systems at their facilities, and these systems must be approved by the Nuclear Regulatory Authority (NDK). The scrap metal importer certificate is issued with a validity period of two years, and any deficiencies identified by the NDK are reported to the Ministry of Environment, Urbanisation and Climate Change.
What Happens When a Radiation Alarm Is Triggered at a Port?
At ports and customs gates in Türkiye, fixed portal monitors known as the RİS (Radiation Monitoring System) are in service. These systems trigger an automatic alarm when they detect radiation above the threshold value in a passing vehicle or container.
The protocol to be followed in the event of an alarm consists of the following steps:
Step 1 — Stop the vehicle/container and secure the area The vehicle or container that triggers the alarm is stopped immediately and moved away from other vehicles and people. No one should wait in the vicinity of the flagged cargo, and personnel should withdraw to a safe distance.
Step 2 — Perform a secondary measurement with a portable detector A measurement is taken from outside the vehicle using a hand-held Geiger-Müller or scintillator detector to identify the source of the alarm. If the dose rate is very high, the measurement is stopped and continued from a greater distance.
Step 3 — Notify the NDK (Nuclear Regulatory Authority) immediately The Nuclear Regulatory Authority serves as the national notification point for radiation emergencies that may occur within, or affect, our country’s borders. All information regarding the source that triggered the alarm (vehicle details, dose rate value, location) must be conveyed in full.
Step 4 — Quarantine area and interim storage Cargo in which a radioactive source is detected is placed in a pit; without excessive delay, it is dispatched — in a dedicated vehicle compliant with radioactive material transport regulations — to the radioactive waste facility of TENMAK (Turkish Energy, Nuclear and Mineral Research Agency) or to an authorised storage site.
Step 5 — Recording and reporting The entire process, from the moment of the alarm to the final disposition of the cargo, must be documented; vehicle details and the type, form and, where applicable, activity of the radioactive material must be recorded.
How Is Radiation Measurement Carried Out on Ships? A Step-by-Step Process
Radiation measurement on board a ship requires protocols of differing depth depending on its purpose (IHM, pre-dismantling, port acceptance, etc.). The general process follows these stages:
1. Preliminary Assessment and Scope Definition
Before measurement, the ship’s operational history is examined:
- Type of cargo carried (oil, chemical, gas, etc.)
- Devices with radioactive sources currently on board or historically present (well-logging equipment, fire detectors, marker devices, etc.)
- Previous survey and IHM documents
2. Classification of Areas
The ship is divided into areas such as the engine room, bilge zone, cargo tanks, piping systems, deck and accommodation spaces. A risk priority is assigned to each area.
3. Surface and Ambient Dose Rate Measurements
Surface and ambient radiation dose rates are measured in each area using Geiger-Müller detectors or scintillator-based instruments. Measurement values are recorded in microsieverts per hour (µSv/h) and compared against natural background radiation.
4. Contamination Survey
Smear (wipe) tests are applied to check for surface contamination; areas that are particularly at risk in terms of NORM — pipe interiors, filter systems and points where deposits may build up — are surveyed.
5. Spectrometric Analysis (When Required)
Gamma spectrometry is applied at points that trigger an alarm or are otherwise suspect in order to identify the isotope. This analysis is critical for determining the type of radiation (Ra-226, Cs-137, Co-60, etc.) and its activity.
6. Reporting and Documentation
All measurement data is entered into an official report, together with area-based maps and tables. The report forms the basis for dismantling the ship, accepting it at a shipyard, or for the IHM process.
What Information Does a Radiation Measurement Report Contain?
A radiation measurement report accepted by the Nuclear Regulatory Authority and international classification societies during the ship recycling process must, as a minimum, contain the following information:
Ship identification details: IMO number, ship name, flag, year of build, GT (gross tonnage), type of cargo carried.
Measurement methodology: Make, model and serial numbers of the instruments used; calibration dates and certificates; measurement standard (ISO 11929, IAEA safety guides, etc.).
Area-based measurement tables: For each measurement point — location, measured value (µSv/h), natural background value and deviation ratio.
Contamination analysis results: Smear test findings, radionuclides detected and activity values.
Conclusion and risk assessment:
- A clear determination as to whether there is any radiological objection or not
- Recommended intervention steps for areas exceeding the threshold value
- Integration with the IHM (where required)
Signatures of authorised parties: The report must be signed by an expert or organisation authorised by TENMAK or the NDK. In official ship recycling processes, the “official letter confirming there is no radiological objection” is the key output of this report.
How Is the Risk of Radioactive Sources in Scrap Ships Detected?
The risk of radioactive sources in scrap ships is an invisible, silent threat that requires an entirely technical measurement process.
The highest-risk areas and sources:
Oil and chemical tankers: NORM build-up is most commonly seen on pipe interiors, in filter housings and at the bottoms of tanks. Naturally occurring radium (Ra-226) and its decay products are the radionuclides most frequently encountered on such ships.
Legacy industrial and navigation devices: Neutron source detectors used on board, americium-241 fire alarm detectors, tritium-based emergency exit signs and old radar equipment can, over the years, become sources that have either been separated from their documentation or forgotten on the ship.
Flooring and paint materials: Some older ship flooring and paints may contain radioactive substances; this must be taken into account when preparing the IHM.
Detection method: The process begins with a surface survey and, in suspect areas, is deepened to spectrometric analysis and, where necessary, laboratory analysis through sampling. The Radioactivity Measurement Laboratories within TENMAK NÜKEN (Nuclear Energy Research Institute) provide gamma spectrometry, gross alpha/beta and liquid scintillation spectrometry analyses on an accredited basis under the TS EN ISO/IEC 17025 standard.
Which Instruments Are Used in Radiation Measurement?
Different detector technologies are used for different measurement purposes:
Geiger-Müller (GM) Counter
This is the most widely used field survey instrument. It detects gamma and beta radiation and displays the dose rate instantaneously in µSv/h or mR/h. Its light and portable design makes it the instrument of choice at port gates, customs points and for surveying ships’ external surfaces. In Türkiye, Geiger-Müller (GM) detector-based RİS (Radiation Monitoring System) units developed domestically by TENMAK-NÜKEN have been installed at maritime, air and land customs gates.
Personal Dosimeter (APD — Active Personal Dosimeter)
Used to monitor the cumulative dose received throughout the day by personnel working in radiation environments. Accredited dosimeter services compliant with the IEC 61526:2013 standard are mandatory in workplaces that require measurement and reporting at defined intervals.
Scintillation Detectors
Offering far greater sensitivity than Geiger-Müller counters, these detectors are used to detect low-level radioactive contamination and to carry out rapid surveys of large-volume spaces (containers, ships’ holds).
Gamma Spectrometry Systems
These determine not only the presence of radiation but also which isotope is present. They distinguish between radionuclides such as Ra-226, Cs-137, Co-60 and Am-241. Portable versions (based on HPGe or NaI detectors) can be used in the field, and it is also possible to carry a suspect sample to a laboratory for more sensitive analysis.
Portal Monitors (Radiation Gate Systems)
These are fixed systems that operate automatically as vehicles or personnel pass through the entrances to ports and shipyard gates. When radiation exceeding the threshold value is detected, they give visual and audible alarms; the alarm can also be integrated with a speed sensor to warn the driver.
How Is Radiation Safety Ensured at Ship Recycling Facilities?
Ship recycling facilities are working environments that require special precautions in terms of NORM risk, lost radioactive sources and contaminated materials within scrap metal.
Administrative measures:
- Making a radiation measurement report and IHM certificate mandatory for every ship to be accepted at the shipyard before dismantling
- Carrying out and recording periodic measurements throughout the dismantling process, as required by the ship dismantling regulation
- Appointing a Radiation Protection Officer (RKS); an NDK-approved certificate is required for this role
Technical measures:
- Installing a portal monitor or fixed radiation monitoring system at the shipyard entrance gate; the NDK must issue a conformity certificate for these systems
- Making the use of active personal dosimeters mandatory for personnel working in high-risk sections (pipe cutting, tank cleaning)
- Establishing a quarantine area and an interim storage pit for materials found to be contaminated
Emergency planning: The protocols to be followed in the event of an alarm must be prepared as written instructions and handed to employees against signature. The NDK maintains the list of organisations licensed to provide transport services for radioactive waste and sources.
The EU SRR and Hong Kong Convention dimension: According to the European Union’s inspection reports, pollution and contamination levels at ship recycling facilities are regularly monitored. For Turkish shipyards seeking to be included on the EU SRR list, compliance with both the IHM requirement and radiation management protocols is a factor that directly affects global competitiveness in this field.
What You Need to Know About Radiation Measurements Under TENMAK and NDK Regulations
In Türkiye, the legislation on radiation measurement and safety is built on a dual structure:
TENMAK (Turkish Energy, Nuclear and Mineral Research Agency): This is the research agency responsible for radioactive material analyses, laboratory services and dosimeter calibration functions. The laboratories within TENMAK-NÜKEN have provided accredited services in the fields of Gamma Spectrometry, Gross Alpha/Beta, Liquid Scintillation Spectrometry and Alpha Spectrometry under TS EN ISO/IEC 17025 accreditation granted by TÜRKAK since 2009.
With the “Regulation on Radiation Protection Training” published in the Official Gazette No. 32818 dated 19 February 2025, the framework for training and certification was updated. The course programmes organised by TENMAK have also been restructured in line with this legislation.
NDK (Nuclear Regulatory Authority): Having taken over the regulatory function of the former TAEK (Turkish Atomic Energy Authority), the NDK holds all authority over licensing, authorisation, inspection and conformity certification.
NDK authorisations of practical importance for the maritime sector:
| Subject of Authorisation | Relevant Organisation |
|---|---|
| Conformity certificate for radiation measurement system (portal monitor) | Scrap metal facilities, international inspection companies |
| Authorisation to operate a radioactive waste facility | RAYK waste facilities |
| Personal dosimetry service | Accredited dosimeter laboratories |
| International inspection company authorisation certificate | Radiation measurement for Type A companies |
NDK Guide for Scrap Metal: The NDK’s “Guide on Radioactivity Monitoring and Radiation Protection in Scrap Metal” defines, step by step, the procedures to be followed in the event that a radioactive source is detected at ports and scrap facilities. This guide is the primary reference source for shipyard and port operators, holders of importer certificates and ship dismantling facilities.
Radiation Emergency Network — RADİSA: RADİSA, Türkiye’s environmental radiation monitoring infrastructure, comprises a total of 211 stations established across 81 provincial centres, 111 district centres and border regions, and continuously measures the gamma radiation dose rate in real time.
What Is the Cost to Businesses of Failing to Carry Out Radiation Measurement?
Neglecting radiation measurement is a risk factor that can produce sudden and severe consequences. These risks can be addressed under five main headings:
1. Harm to Human Health and Legal Liability
Dismantling workers, shipyard personnel or scrap carriers can be exposed to a radioactive source without noticing. Chronic exposure increases the risk of cancer; an acute high dose leads to severe radiation injury. In such cases, the employer faces both criminal liability and substantial compensation obligations.
2. Suspension of Shipyard Operations
When radioactive contamination is detected, the facility is immediately placed under quarantine. The decontamination process can take weeks — sometimes months — depending on its scale. During this time, production halts and existing contracts are suspended.
3. Administrative Sanctions and Licence Revocation
Non-conformities identified during NDK inspections may result in administrative fines, deficiency notices and licence suspension decisions. Revocation of the scrap metal importer certificate means the company must halt its scrap imports altogether.
4. Loss of International Reputation and Commercial Sanctions
Türkiye’s ship recycling sector, and Aliağa in particular, is under close scrutiny by the EU and international non-governmental organisations. Facilities found to be non-compliant in terms of radiation management may be removed from the EU SRR list; this means EU-flagged ships can no longer be sent to that shipyard for dismantling. The lost business volume can be measured in millions of euros per year.
5. Dispersal of Contaminated Steel and Cascading Costs
If scrap steel containing an undetected radioactive source is melted, the radioactive material disperses within the furnace, transfers into the products, and can contaminate the entire production batch. Worldwide, the cost of such incidents has reached the level of hundreds of millions of dollars in a single case.
How Should You Choose the Right Radiation Measurement Service?
The characteristics that an authorised and reliable service provider should possess:
NDK conformity certificate or authorisation certificate: In Türkiye, the relevant NDK authorisation is mandatory for the installation, maintenance or provision of radiation measurement services. A Type A licence with international inspection company status is a prerequisite for carrying out measurements in the field.
Accredited calibration: The instruments used must have been calibrated at TÜRKAK-accredited laboratories, and calibration records must be kept up to date.
Experience and references: Prefer companies with experience in ship dismantling, IHM measurement and port scrap inspection. Active references in Aliağa and other shipyard regions are an indicator of sector expertise.
Reporting standards: The reports produced must be of a standard acceptable to the NDK, international classification societies (Lloyd’s Register, Bureau Veritas, DNV, etc.) and EU SRR requirements.
Multi-parameter service capability: Companies that can perform not only surveys but also gamma spectrometry, contamination analysis and NORM assessment offer an integrated solution across ship recycling processes.
Get Expert Support for Radiation Measurement Services
At Orionis Shipping, we provide comprehensive radiation measurement services compliant with NDK regulations, aimed at ship recycling, IHM certification and port scrap inspection. From pre-dismantling radiation analysis to radiological assessment integrated with the IHM, we deliver both regulatory compliance and occupational safety for every operation in your portfolio.
Contact us for information about our services and pricing.
This content has been prepared for informational purposes. For your legal obligations, please refer to the Turkish Nuclear Regulatory Authority (NDK), TENMAK and the current legislation.
Tags: radiation measurement, radiation on ships, NORM radioactive material, scrap ship radiation, radiation measurement report, IHM inventory of hazardous materials, ship recycling radiation, TENMAK, NDK nuclear regulation, Aliağa ship dismantling, Geiger counter, portal monitor, gamma spectrometry, radioactive source detection, EU SRR radiation
