Radiation Shielding

The purpose of radiation shielding is to limit radiation exposure to employees and members of the public outside the X-ray room to an acceptable level, as determined by legislation.

How It Works

Radiation shielding design can be calculated for both existing buildings and off the plan. Speak to us about our design services.

The shielding requirements are calculated using NCRP Report No. 147 “Structural Shielding for Medical Imaging Facilities”, 2004 and “BIR 2012”. The report include the minimum shielding required in terms of millimetre thickness of lead.

Preparation of Radiation Shielding

In the preparation of radiation shielding needs for an X-ray facility, several factors need to be taken into consideration, including:

  • The direction and energy of the X-ray beams
  • The amount of radiation involved, i.e., use factor
  • The distance between the radiation source and the operator as well as the distance
    between the radiation source and members of the public.
  • Composition of existing walls or other barriers.
  • Maximum permissible exposure limits as determined by legislation. This is currently
    20mSv/year for occupationally exposed persons and 1mSv/year for members of the
    public. Where both members of the public and operators (staff) are likely to be
    exposed, it is the lower of these two values that will be used in calculations.

The Principle of ALARA

Combined with the factors mentioned above used for the shielding calculations, we also follow the ALARA (As Low as Reasonably Achievable) Principle. The ALARA principle, as recognised by legislative bodies, states that in all situations every effort must be made to ensure that radiation exposure to people is kept as low as reasonably achievable, with economic and social factors being considered.

What we require to calculate shielding requirements

To calculate shielding requirements, RadTest Australia will require a floor plan showing:

  • X-ray room(s) with location of X-ray table, vertical bucky and control panel
    Dimensions of room(s)
  • Constitution of surrounding walls – e.g., stud/plaster, brick, etc
  • Areas adjacent to X-ray room(s) – e.g., toilet, office, passage, etc
  • For external walls, distance to next building (if applicable)
  • If multi-storey, constitution of ceiling and floor
  • The maximum kVp of X-ray unit and (estimate of) average mAs per exposure and an
    estimate of average number of patients per week and average number of exposures
    per patient

All work is carried out by accredited and licensed inspectors.

Frequently Asked Questions

A shielding report from RadTest Australia will provide recommendations about how much shielding is required for your X-ray room, and will provide one component of the necessary documentation required for your Vic Dept. of Health application.

To guide your project and ensure patient and staff safety, and to meet the requirements set by the regulator in your state, e.g. Victorian Dept. of Health Radiation Safety Section.

At RadTest Australia, we would always recommend seeking shielding to advice prior to commencing fit-out of your radiation area, please contact our helpful team for more information regarding the timing of your project.

Mostly likely, yes! Please speak to the friendly staff at RadTest Australia, we can provide more information about when you would need a new shielding assessment. It is normally required by the regulator any time conditions change at your licenced premises.

Yes, anytime conditions change at your premises, or you need to add a new location to your licence, you will need a new shielding assessment.

In most cases, this is not required. The regulator in your state will require evidence that the recommended shielding has been, or will be installed. Mostly, records from your builder/shielding installer, e.g. photos/quotes/ invoices, etc. will provide sufficient evidence. Please speak to the knowledgeable staff at RadTest Australia for more information.

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