PNRA Approval for X-Ray & CT Rooms: Radiation Shielding Guide

Every hospital, clinic or diagnostic centre in Pakistan that installs an X-ray machine, CT scanner, fluoroscopy unit, mammography system, cath lab or dental X-ray must deal with two closely linked issues: radiation shielding and PNRA approval. Get them right, and the imaging department opens on time and protects staff and the public for decades. Get them wrong, and owners face failed surveys, expensive rework, delayed licences and, most seriously, unnecessary radiation exposure.

This guide explains radiation shielding for X-ray rooms in Pakistan, along with CT and other diagnostic rooms, in practical terms. It covers how shielding is calculated, what materials are used, how rooms should be laid out, and how the design and construction process fits with the requirements of the Pakistan Nuclear Regulatory Authority (PNRA).

🏢 About Hospital Design Hub

Hospital Design Hub is a specialist hospital design and construction company, established in 2000 and focused on healthcare infrastructure: design, construction, consultancy and project management, and the renovation and maintenance of hospital facilities. With more than 50 successfully completed projects, our team has worked on healthcare facilities across Pakistan, including projects such as LDMC, MCH Islamkot, King Edward Medical University / Mayo Hospital, and UOL Hospital Lahore.

Imaging departments are a regular part of our hospital projects. We coordinate room layouts, structure and MEP with qualified radiation protection professionals, and inspect shielding on site before it is covered up.

☢️ Why Radiation Shielding Matters

Diagnostic X-rays are safe for patients when properly justified and optimised, but radiation scattered from the patient and leaking from the equipment travels in all directions. Without adequate barriers, it passes through ordinary walls, doors and floors into waiting areas, offices, corridors and neighbouring rooms. Radiographers, nurses, receptionists, other patients and even people in adjoining buildings can be exposed every day, year after year.

International radiation protection principles, reflected in the basic safety standards of the International Atomic Energy Agency (IAEA) and the recommendations of the ICRP, set dose limits for workers and members of the public. Commonly cited limits are an average of 20 mSv per year for occupational exposure and 1 mSv per year for members of the public. Good shielding design keeps doses well below these limits, following the principle of keeping exposure “as low as reasonably achievable” (ALARA).

🏛️ The Role of PNRA

In Pakistan, the use of radiation sources and radiation-generating equipment in medicine is regulated by the Pakistan Nuclear Regulatory Authority (PNRA). Facilities using diagnostic radiology equipment must be authorised by PNRA, and the authority’s regulations cover radiation protection, facility design, staff qualifications, monitoring and record keeping.

In practice, owners should expect PNRA-related requirements to include:

• A facility layout and shielding details for each radiation room.
• Information about the equipment to be installed.
• Appointment of a qualified person responsible for radiation protection.
• Personal dose monitoring for radiation workers.
• Warning signs, lights and access control for radiation areas.
• Radiation surveys to verify that shielding performs as designed.

Regulatory requirements and procedures are updated from time to time. Always check the current requirements directly with PNRA or through a qualified radiation protection professional before submitting your application.

🧮 How Shielding Is Calculated

There is no single “standard thickness” that fits every X-ray room. Shielding must be calculated for each barrier (every wall, the floor, the ceiling, doors and windows) using a recognised method, such as the approach in NCRP Report No. 147 for medical X-ray imaging facilities. The main inputs are:

The result is a required lead-equivalent or concrete thickness for each barrier. For a busy general radiography room, walls commonly need in the order of 1–2.5 mm lead equivalent, but the actual value can be higher or lower. CT rooms, with high workloads and scatter in all directions, often need more. Only a calculation for your room and workload is valid.

🧱 Shielding Materials Compared

📐 Designing the X-Ray and CT Room Layout

Shielding thickness is only part of the story. A good layout reduces the shielding needed and makes daily work safer:

• Room size: larger rooms keep people further from the source. Typical general radiography rooms are around 20–30 m² and CT rooms around 30–45 m² plus a control room, depending on equipment.
• Control room position: the operator should see the patient through lead glass and never stand in the primary beam path.
• Primary beam direction: orient the chest stand and table so the primary beam points at walls backed by low-occupancy spaces or outside walls where possible.
• Adjacent spaces: avoid placing waiting areas, children’s areas or busy offices directly behind primary barriers.
• Above and below: floors and ceilings must be considered too, especially in multi-storey hospitals where a ward or clinic sits above the radiology department.
• Patient changing: changing cubicles opening into the room, with shielded doors or located outside the radiation zone.
• Warning systems: illuminated “X-ray in use” warning lights at entrances and standard radiation warning signs.

For department-level planning, read our guide to designing diagnostic and imaging centres and our page on imaging and diagnostic facility setup.

🔩 Construction Details That Cause Shielding Failures

Many radiation rooms in Pakistan fail their first survey not because the design was wrong, but because the construction left gaps. The most common problems are:

1. Gaps at joints between lead sheets or lead-lined boards without overlapping strips.
2. Unprotected penetrations for electrical boxes, conduits, ducts and pipes that cut through the lead layer.
3. Door frames without lead lining, leaving a gap between the door leaf and the wall shielding.
4. Shielding stopping at the false ceiling instead of continuing to the height required by the design.
5. Hollow or poorly filled masonry assumed to be solid.
6. Floor slabs thinner than assumed, or with services cut into them.
7. Last-minute changes to door or window positions without updating the shielding design.

The solution is simple but requires discipline: inspect and photograph the shielding before it is covered, keep records of lead thickness and overlaps, and have the construction checked against the approved drawings. We include this as a standard step in all imaging projects.

📋 Step-by-Step: From Design to Approval

⚖️ New Build vs Retrofitting an Existing Room

✅ Pros and Cons of Different Shielding Approaches

🦷 Special Cases: Dental, Mammography, Cath Lab and Radiotherapy

• Dental X-ray (intraoral, OPG, CBCT): lower energies and workloads than general radiography, but still require assessment and appropriate shielding, especially in small clinics next to waiting areas.
• Mammography: low energy, so shielding requirements are modest, but privacy and patient comfort are important design factors.
• Cath lab and interventional suites: high workloads and long fluoroscopy times; shielding, ceiling-mounted protective screens and staff protection are critical.
• Radiotherapy (LINAC): a completely different scale, requiring massive concrete bunkers designed to separate standards. We cover this in a dedicated LINAC bunker guide.

For specialty facilities, see our guides to cardiac hospital design and cancer treatment centre design.

👷 Radiation Safety After Opening: Operations Matter Too

A well-shielded room is the foundation of radiation safety, but it is not the whole system. Once the department opens, day-to-day practices keep doses low and keep the facility compliant:

• Radiation protection officer: a designated, trained person oversees radiation safety, maintains records and acts as the contact point for the regulator.
• Personal dose monitoring: radiation workers wear personal dosimeters, and their doses are recorded and reviewed regularly. Unusual readings are investigated.
• Protective equipment: lead aprons, thyroid shields, mobile lead screens and, for interventional work, ceiling-suspended shields and lead glasses. These should be stored properly on hangers and checked periodically for cracks.
• Quality assurance of equipment: regular checks of X-ray output, image quality and safety interlocks keep patient doses optimised.
• Access control: doors closed during exposures, warning lights working, and no unnecessary people in the room.
• Pregnancy and patient safety procedures: signage asking female patients to inform staff if they may be pregnant, and justification of every examination.
• Record keeping: survey reports, equipment service records, dose records and training records kept ready for inspection.

Designing the department with space for apron racks, a lockable records cabinet, clear signage and good sightlines from the control room supports all of these practices.

💰 What Affects the Cost of Shielding?

Owners often ask how much shielding will add to their budget. The honest answer is that it depends heavily on the room and the building, but the main cost drivers are predictable:

In our experience, the cheapest shielding is the shielding that is designed correctly and built correctly the first time. Rework after a failed survey often costs more than the original shielding work.

✅ Owner’s Checklist Before Installing Imaging Equipment

1. Equipment model and specifications confirmed with the supplier.
2. Room layout approved, showing uses of all neighbouring spaces, including above and below.
3. Shielding calculation completed by a qualified professional and integrated into drawings.
4. Structural check done for equipment weight and heavy shielding elements.
5. Electrical supply, earthing and HVAC designed for the equipment.
6. Shielding inspected and photographed before walls and ceilings are closed.
7. Warning lights, signs and door arrangements installed.
8. Radiation protection officer appointed and dosimetry arranged.
9. Post-installation radiation survey completed and documented.
10. Regulatory authorisation obtained before routine patient use.

❓ Frequently Asked Questions

Do X-ray rooms in Pakistan need PNRA approval?

Yes. Medical facilities using X-ray and other radiation-generating equipment are regulated by the Pakistan Nuclear Regulatory Authority and must meet its authorisation and radiation protection requirements before routine use.

How thick should lead be in an X-ray room?

There is no universal thickness. Busy general radiography rooms often need around 1–2.5 mm lead equivalent in walls, but the correct value must be calculated for each barrier based on equipment, workload, occupancy and distance.

Can brick walls provide radiation shielding?

Solid, well-built masonry can contribute to shielding, but its density and quality vary. It usually needs to be verified by calculation and survey, and often supplemented with lead or barium plaster.

Do floors and ceilings need shielding?

Yes, if rooms above or below are occupied. Slab thickness and density must be considered in the calculation, especially in multi-storey hospitals.

What is a radiation survey?

After equipment installation, a qualified professional measures radiation levels around the room during exposures to confirm that shielding performs as designed and that doses outside the room are acceptable.

Does a CT room need more shielding than an X-ray room?

Often yes, because CT scanners have high workloads and produce scatter in all directions. The exact requirement depends on the calculation for the specific room.

Can an existing room be converted into an X-ray room?

Yes, if its size, structure and neighbouring spaces are suitable. Conversion usually involves adding lead-lined walls, doors and windows, and checking floor and ceiling protection.

Do dental clinics need radiation shielding?

Dental X-ray units also need assessment and appropriate protection. Requirements are usually lighter than for general radiography, but the clinic must still meet regulatory requirements.