An Introduction to Radiation Protection

Figure 1.1

The atomic system of zinc.

Figure 1.2

The atomic systems of hydrogen and helium.

Figure 1.3

The three isotopes of helium.

Figure 2.1

Typical &# 946; spectrum.

Figure 2.2

Variation of activity with time.

Figure 2.3

A portion of the nuclide chart.

Figure 3.1

Ionization of a helium atom by an &# 945; particle.

Figure 3.2

Ionization chamber system.

Figure 3.3

Flux from a point source.

Figure 3.4

The relationship of units (with acknowledgements to Lt Cdr J. Kelly, RN).

acknowledgements to Lt Cdr J. Kelly, RN

Figure 3.5

The international trefoil symbol for radiation (black on yellow).

Figure 3.6

The new symbol for very high-activity sources.

Figure 4.1

Schematic illustration of human physiology.

Figure 4.2

Structure of human cell (schematic).

Figure 5.1

Average annual dose to the UK population. Adapted with kind permission from the Health Protection Agency leaflet, 'What is Radon?', ^© Health Protection Agency, Chilton, 05/2009.

©Health Protection Agency.

Figure 5.2

Passive Radon Metre. Adapted with kind permission from Report HPA-RRP-001 'Ionising Radiation Exposure of the UK Population: 2005 Review' by S J Watson et al (2005), © Health Protection Agency.

©Health Protection Agency.

Figure 7.1

Ion chamber system.

Figure 7.2

Gas amplification.

Figure 7.3

Ionization, excitation and trapping.

Figure 7.4

Dose–density curve.

Figure 7.5

Direct current amplifier – negative feedback.

Figure 7.6

Function of a discriminator.

Figure 7.7

Discriminator bias characteristic.

Figure 7.8

Plateau for GeigerñMüller counter.

Figure 7.9

Counting equipment – schematic diagram.

Figure 7.10

Cobalt-60 &# 947;-ray spectra from a sodium iodide crystal (solid line) and a germanium (HPGe) detector (dotted line).

Figure 7.11

Basic ratemeter circuit.

Figure 7.12

Shielded calibration room with remote operation (after Barnes and Taylor).

Figure 8.1

The line source.

Figure 8.2

Variation of &# 947; dose rate with absorber thickness

Figure 8.3

The three main neutron reactions.

Figure 8.4

Energy response curves of various detectors.

Figure 8.5

Advanced portable survey meter (courtesy of Thermo Electron Corporation).

courtesy of Thermo Electron Corporatior

Figure 8.6

Neutron monitor (courtesy of Thermo Electron Corporation).

courtesy of Thermo Electron Corporatior

Figure 8.7

The film badge. (After Heard and Jones, courtesy of the United Kingdom Atomic Energy Authority.) Patterns are typical of (a) a high-energy &# 946; exposure, (b) an X-ray exposure and (c) a &# 947; exposure.

courtesy of the United Energy Authority

Figure 8.8

Thermoluminescent dosimeter (courtesy of the Health Protection Agency). PTFE, polytetrafluoroethylene; TLD, thermoluminescent dosimeter.

courtesy of the Health Protection Agency

Figure 8.9

Optically stimulated luminescence (OSL) dosimeter (courtesy of Landauer, Inc., reproduced with permission).

courtesy of Landauer, Inc., reproduced with permission

Figure 8.10

Commercially available electronic personal dosimeter (courtesy of Thermo Electron Corporation).

courtesy of Thermo Electron Corporatior

Figure 9.1

Typical elimination curve of a radionuclide in the body.

Figure 9.2

Variation of dose rate with time following an intake of a radionuclide.

Figure 9.3

Schematic diagram illustrating four levels of containment.

Figure 9.4

Protective clothing and equipment. (a) Coverall. (b) Coverall and gloves. (c) Hooded coverall, gloves and respirator. (d) Pressurized suit (courtesy of NDA photo library, reproduced with permission).

courtesy of NDA photo library, reproduced with permission

Figure 9.5

Schematic drawing of a glove box.

Figure 9.6

Schematic drawing of a fume cupboard.

Figure 9.7

Dual (&# 945; and &# 946;) contamination probe and ratemeter.

Figure 9.8

Particulate air sampler (courtesy of Bird and Tole Air Sampling Products).

courtesy of Bird and Tole Air Sampling Products

Figure 10.1

Typical &# 946;-absorption curve.

Figure 10.2

Determination of half-value thickness for a &# 946; emitter.

Figure 10.3

Relationship between half-value thickness and &# 946;-ray maximum energy.

Figure 10.4

Decay curve of mixed ³⁸Cl and ²⁴Na sample.

Figure 11.1

Fission.

Figure 11.2

Relative fission product yield.

Figure 11.3

Approximate fission-product &# 946; inventory in fuel, irradiated for 2000 days at 1 MW.

Figure 11.4

Primary system of a pressurized water reactor.

Figure 11.5

Schematic illustration of a pressurized water reactor.

Figure 11.6

Schematic illustration of a boiling water reactor.

Figure 11.7

Sources of radiation in a nuclear reactor system.

Figure 12.1

A simple marine food chain.

Figure 12.2

Dispersion from chimney stacks.

Figure 13.1

A typical rotating anode X-ray tube.

Figure 13.2

Simplified power supply for X-ray set.

Figure 13.3

The spectrum of X-ray photons from a typical X-ray tube and generator.

Figure 13.4

A typical nuclear density gauge (NDG) (courtesy of Humboldt Scientific, reproduced with permission).

courtesy of Humboldt Scientific, reproduced with permission

Figure 14.1

Principle of fluoroscopic examination.

Figure 14.2

The use of fluoroscopy equipment. Reproduced from Huntingdon Daily.com

reproduced from Huntingdon Daily.com

Figure 14.3

Schematic illustration of transmission computed tomography.

Figure 14.4

A modern computed tomography installation (courtesy of Philips Healthcare).

courtesy of Philips Healthcare

Figure 14.5

Treatment of a brain tumour using a linear accelerator teletherapy unit. (Image courtesy of Varian Medical Systems of Palo Alto, California. Copyright (2012), Varian Medical Systems. All rights reserved.)

Figure 14.6

Schematic illustration of gamma camera used in nuclear medicine imaging.

Figure 14.7

Thyroid radioiodine uptake test.

Figure 15.1

The basic steps in risk assessment.

Figure 15.2

Fault tree for a fire breaking out.

Figure 15.3

Event tree for a fire in an office building.