Blue Book - Radiation Shielding for Medical Instalations

The Blue Book
Published, 1988, by predecessor of
Radiological Protection Institute of
Ireland (RPII)
Prof fJim Ml Malone
Robert Boyle Prof of Medical Physics
Trinity College, g, Dublin
IAEA, Vienna

Problems with Blue Book
• Changes in Legislation,
Technology, Clinical Practice,
Building Style, Building
Materials
• Changes in Dose Limits and
Constraints
• Use of Upper Floors
• Need illustrated floor plans
• Advice on Ceilings,
• Higher levels of walls
• Practical Tips and Solutions
• OBJECTIVES
• Preference for
comprehensive local
l
solution
• Not to innovate, but
to produce a reliable
practical manual or
code.

Issues, 1: Equipment

Issues 2: New Problems
• Ward walls not solid
• Theatre workloads not
consistent with modern
practice.
• Other – recovery rooms,
endo suites, lithotripsy,
cardiac pacing
• Radionuclides in Theatres
• PET shielding

Issues 3: Dose Constraints
Category of
Personnel
Dose
Constraint
t
1998
mSv/year
Dose
Constraint
t
2001
mSv/year
Exposed
50 5.0 10 1.0
Worker
All others 0.05 - 1.0 0.3

Issues 4: Medical Physics
Medical Physics Support
• Deficits in numbers, leadership and
academic involvement/connectivity
i i
• Often poor, or inadequate training, and
narrow or inadequate experience
• Risk of litigation and difficulties with public
accountability

Design Code (2 nd edition)
• About 100
pages incl.
Appendices
1. Legal and Administrative
Framework
2. Radiation Protection, Project
Management and Building
Projects
3. Rdil Radiology Room Design and
Layout
4. Nuclear Medicine
5. Shielding Calculations
6. Some Practical Considerations
www.rpii.ie
RPII, 3 Clonskeagh Square, Dublin 14, Ireland

1. Statutory Framework
• The Radiological Protection Act, 1991 (Ionising
Radiation) Order 2000 (SI No. 125 of 2000)
• European Communities (Medical Ionising i Rditi Radiation
Protection) Regulations 2002, 2007 (SI. No. 478 of
2002 & SI. No. 303 of 2007)
• RPII Licensing System and Requirements
• Related EU Directives

2. Radiation Protection, Project
Management and Building Projects
• The Radiation Safety Committee
• The Radiation Protection Advisor
• Project Teams, New Building Design Cycle,
Refitting Buildings
• Dose Limits and Dose Constraints
• Risk Assessments
• Site visits essential
Issue of New Build versus Conversion/Refit

Radiology Room Design and Layout
• Radiology Room
Types
• General Comments on
Shielding
• Radiography Rooms
– General
– Chest Room
– Mammography
– DXA
– Dental
• Fluoroscopy Rooms
– General Fluoroscopy
– Interventional
Radiology and
Cardiology
• CT
• Shared Function
Rooms (A&E, Theatres,
wards)
• Equipment in Trailers

3. Radiology Room Design and Layout
General Radiology
• Two-corridor Design
• Large enough for trolleys, table and
chest radiology
• Typical room sizes given
• Generally 2mm Lead – assess on
individual basis
• Primary Beam absorber
• Staff entrance behind protective screen
• Typical screen lengths presented
• Chest stand positioned to minimise
scatter entering protective ti console
• Changing cubicles
Specific Requirements for each type of facility
Examples of Good Layouts

3. Radiology Room Design and Layout
Dental Surgery
No shielding required if: < 20 exps/wk
and 2m between patient and all boundaries
CT
Separate staff area – Other staff present
Need good view of door and patient
Scanner angled for access and visibility
MSCT: 3-4mm Pb

DXA and CT

Design Criteria
ia
Corrido
Corridor
Corridor

9/3/2009

Mobile X‐Ray Equipment

Equipment not in Rooms

Equipment not in Rooms

Equipment not even in Building
• Re‐shielding often
means complete refit
• Hospital can’t do
without equipment for
6 months
• Trailer arrives ‐‐‐‐‐
• Trailer

5. Shielding Calculations
X‐Ray
• Review of two widely used
Shielding Methodologies
– BIR, 2000
– NCRP, 2004
• Variables
– Distance from Barrier
– Workload
– Occupancy
• BIR: Workload is based (ESD) and
(DAP)
• NCRP: Workload based on “beam‐
on” time. in mA min per week
Issue of New Build versus Conversion/Refit

Workload

Workload
• Either DAP (BIR) or mA‐min/week min/week (NCRP)
• Try and base figures on real audit/projection
• Historical i or published data can mislead il • If no other option, use published data
• Transparency and accountability to the public
• Defendable legally (reasonable patient, not reasonable doctor)

Occupancy

Occupancy
• Occupancy of adjoining areas to be assessed
• Try and get real information
• Consider rooms on other side of corridor
• Extremes: Office, 100%; Unattended carpark,
2.5 to 5 %
• Reservation about NCRP door value in new
builds, and Remember:
• Transparency and accountability to the public
• Defendable legally (reasonable patient, not reasonable doctor)

General Radiographic Room
Ceiling (BIR method)

General Radiographic Room
Ceiling (NCRP method)
General Rm Window, scatter only, at 10 m

6. Practical Considerations
• Building Materials
– Lead sheet and lead
products
– Concrete and concrete
Blocks
– Barium Plaster
– Brick
– Gypsum Wallboard
– Lead Glass
– Lead Acrylic
• Walls
• Floors and Ceilings
• Doors
• Windows
• Staff Areas
• Joints, Services, Openings
and Perforations
• Assessment of Shielding
• Nuclear Medicine
ALWAYS NEED TO VISIT AND SEE IMPLEMENTATION

9/3/2009

Lead Codes
Code No. 3 4 5 6 7 8
Nominal Thickness (mm)
1.32 1.80 2.24 2.65 3.15 3.55
Weight (kgm ‐2 ) 14.6 19.5 24.44 29.3 34.2 39.1
Cost (Relative)
• When installed as part of a new build, lead is not
very dear relative to other costs

Some Data 2:

Some Data Figure C 6
• Also f room; Some Data Table C2
Also f room; Some Data Table C2
and C3,4,or Fig C6 and page 101

• Advice for imaging
facilities located on
upper floors
Issues
• Advice for shielding of
windows on upper
floors
• Transparent,
• Accountable
• Defendable

CONCLUSION
www.rpii.ie
RPII
3 Clonskeagh Square,
Dublin 14
Ireland