Nuclear radiation protection

Nuclear radiation protection is the processes and principles of ensuring that a facility that handles radiation keeps this radiation at an acceptably low level.

TÜV SÜD advises you on nuclear radiation protection following the three key radiation protection principles. All these are part of the ALARA approach – As Low As Reasonably Achievable – which aims to avoid individuals receiving even the smallest dose. Taking economic aspects into account, we also apply the ALARP principle – As Low As Reasonably Practicable. We achieve ALARP through forward-thinking design solutions and taking these key radiation protection principles into account.

The three key principles are:

• Time 
  The effects of radiation exposure build up over time. Therefore, workers need to limit their time near radioactive sources and complete their work as quickly as possible. Monitoring radiation levels in critical areas in the nuclear power plant is crucial to decide on the most efficient and effective approach to work and equipment maintenance, while minimising workers’ exposure.

• Distance 
  Being further away from radiation sources reduces radiation exposure. In fact, radiation exposure is inversely proportional to the square of the distance. This means that being twice as far away from the radiation sources reduces exposure by a quarter (and not a half). Nuclear power facilities are using remote handling and robotics more often to increase the distance between workers and equipment.

• Shielding 
  Nuclear radiation shielding usually comprises one or more barriers of lead, concrete or water which will absorb some radiation as it passes through. The amount and type of shielding primarily depends on the type of radiation and therefore its source. However, it is important to note that the shielding’s installation must comply with all regulations and standards as laid out in the operator’s licence. 

As experts in the field, TÜV SÜD offers support for assessing structural, technical and administrative radiation protection measures. 

We examine approval requirements when submitting an application, and review radiation protection documentation such as radiation protection instructions and work instructions. 

We monitor radiation and activity from conception to implementation and maintenance support in a lab. We advise on external and internal radiation exposure controls, nuclear radiation shielding design, optimising using recognised computer codes, and measuring clearance. 

When the time comes to decommission your facility, we will help you get approval from the relevant authorities who cover residues, buildings, rooms and components. We will liaise with the respective authorities and carry out all the control measurements required.

Protecting your radiation protection laboratory

In the close-up, enclosed setting of a radionuclide laboratory, the three radiation protection principles are more important than ever. You must enforce a clear set of rules to ensure the safety of everyone at the facility. These may include monitoring radiation levels with dosimeters, wearing protective clothing, and installing radiation shields on equipment.

TÜV SÜD’s experts can support you in drafting an Operations Manual for your radionuclide laboratory to guarantee the highest level of safety. We can also design procedures to ensure, for example, that any contaminated clothing or material is disposed of according to approved guidelines.

Monitoring in our own radiation safety lab

TÜV SÜD’s own filter test laboratories provide multiple test methods to determine the retention efficiency of iodine filters, and filter efficiency and performance index of the materials used. This is invaluable to nuclear power plant operators, iodine therapy stations and manufacturers of active carbon or respiratory filters. We can also perform on-site testing of aerosol filters with uranine testing equipment according to DIN EN ISO 16170 as well as on-site inspections of iodine filter systems.

We have achieved the following accreditations for our testing services:

• DIN ISO 9001:2015 for TÜV SÜD Energietechnik GmbH BW. 
• DIN EN ISO/IEC 17025:2018 for TÜV SÜD ET’s radiation measurement laboratory. 
• DIN EN ISO/IEC 17020:2012 (Type A) for TÜV SÜD ET’s Radiation Protection Department as part of the energy technology inspection body for in the inspection field of radiation protection. 

We understand how even small levels of radiation can affect the smooth operation of equipment and technology in a facility or laboratory. Using cutting edge equipment, our experts can detect and measure decay and ensure that equipment is always operating within safe parameters. We can then advise on controlling external and internal radiation exposure as well as improved nuclear radiation shielding designs.

Radiation measurements carried out in TÜV SÜD’s laboratories

In our radiation measurement laboratories, we carry out radioactivity determinations in materials of all kinds. We do this primarily using gamma spectrometry, alpha and beta total measurements and liquid scintillation measurements (for soft beta emitters such as H-3, C-14, Ni-63 and others). Our measuring equipment is ideal for measuring both radon and natural radioactivity, particularly from the thorium and uranium decay series.

Dealing with naturally occurring radioactive material across industry

With the incorporation of EURATOM basic standards into national law within EU member states, businesses need further measures to protect individuals and groups. For example, employees who handle NORM (Naturally Occurring Radioactive Material) residues at work are considered part of the general population.

In certain sectors, such as the titanium dioxide, steel, and oil and gas industries, materials used may contain small, but not insignificant, amounts of naturally occurring radiation. In the waterworks sector, filter gravel, sand, exchange resins and other materials used in groundwater treatments and subject to chemical processes are classed as residues that require assessment.

In such cases, employers are responsible for minimising the exposure of their employees and others to hazardous materials, complying with NORM exposure limits as set down by law, and for the safe disposal of any waste resulting from NORM.

Processing NORM usually falls into one of three categories.

1. Using radioactive substances for their chemical or physical properties.
2. Producing radioactive waste because of extracting substances from natural minerals or ores. 
3. Moving radioactive material from one part of the environment to another where it is not normally found.

TÜV SÜD has supported clients from a wide cross-section of industries to develop and implement a NORM safety policy. This would set out general precautions for minimising exposure within the organisation as well as defining any personal protective equipment needed when handling material. The policy also covers management plans for storing, labelling, cleaning, and disposal of NORM waste.

Radon measurement for homes, offices and public buildings

According to the World Nuclear Association, Radon accounts for around 42% of background radiation. Radon is a naturally occurring radioactive gas that is emitted from the ground by certain rocks and soils. As it disperses easily into the atmosphere, Radon levels are generally low outdoors. However, the radon hazard builds up in indoor environments such as offices, schools, and homes and, with long-term exposure, can be a major cause of lung cancer.

Mitigations from radon are relatively straightforward. High radon levels in buildings are usually caused by air flowing into the house through gaps and cracks in the groundwork, flooring, or piping. The flow of air is caused by a difference in pressure outside (high) to inside (low). You can minimise radon hazards by:

Installing an underfloor radon sump system

One of the most effective methods; a sump (a small chamber or void) is dug next to the building. radon is drawn into the sump by a fan through a pipe and then vented out into the atmosphere.

Depressurising the soil

This involves ventilating the underfloor and drawing out air and gas (sometimes using a fan) through a pipe leading to the roofline. In addition, air bricks could be installed to help further ventilate the building.

Introducing positive ventilation

Air is blown into inhabited spaces through the roof or loft, thereby cutting radon hazards by diluting the gas in the building and reducing seepage into the structure through increased pressurisation.

Identifying and sealing entry points and foundation cracks 

This is one of the most disruptive solutions, as carpets, floorboards and other fittings will need to be removed. It is important that all cracks and points are sealed otherwise it may have a negligible effect on radon levels. 

TÜV SÜD’s radiation laboratory can help you measure the level of radon in buildings and workplaces and support you to fulfil your obligations as the responsible person under the German Radiation Protection Act (Sections 124 and 128 Strahlenschutzgesetz – StrlSchG). 

In addition, our experts have been determining average radon air concentrations for competent authorities for several years and can identify areas in which buildings and workplaces exceed the legal reference values for radon-222.

We can also help manufacturers of building products to determine the specific activity of radionuclides (as per Section 134 StrlSchG) before placing products on the market.