Health Physics Topics

The Health Physics portion of the qualification exam is meant to test the student’s knowledge of both the policy and technical aspect of this specialty in the nuclear engineering department. Courses that will help prepare the student for this qualification exam include:

NUEN 604 Radiation Interactions and Shielding
NUEN 605 Radiation Detection and Nuclear Materials Measurement
NUEN 612 Radiological Safety and Hazards Evaluation
NUEN 613 Principles of Radiological Safety

The following outline describes the material covered by the exam:

Stochastic processes
- Independent events
- Poisson statistics
- Theoretical resolution of energy deposition
- Deviation from Poisson statistics – Fano factor

Nuclear physics basics
- Field descriptions
- Interaction of radiation with matter and interaction rates
- Radioactive decay
  - Half-life, mean life, decay constant, activity
  - Simple decay
  - Composite decay
  - Serial decay
  - Activation /decay relations
- Nuclear decay schemes
- Shielding and radiation attenuation

Ionizing radiation
- Types and sources
- Characteristics
- Field quantities
- Interaction with matter
  - Ionization, excitation, W-value
  - Range, CSDA range, density thickness, mean-free path
  - Stopping power, linear energy transfer, lineal energy transfer
  - Compton effect, photoelectric effect, pair production
    - Attenuation coefficients
    - Rayleigh scattering
    - Photonuclear interactions
- Quantities describing interactions
  - Kerma
  - Absorbed dose
  - Exposure
Radiation measurement and counting
- Theory
- Gas-filled detectors
- Scintillation detectors
- Semiconductor detectors
- Special detectors
Dosimetry
- Fundamentals and concepts
- Cavity theory
  - Bragg-Gray theory
  - Spencer cavity theory
  - Burlin cavity theory
  - Fano theorem
  - Other cavity theories
  - Interfaces
- Radiation equilibrium
- Charged particle equilibrium
  - Distributed sources
  - Indirectly ionizing radiation
  - Failure of CPE
- Transient charged particle equilibrium
- Active and passive dosimeters
- Mixed field measurements
- Calibration
- Quantities in radiation protection
  - Quality factor (radiation weighting factor)
  - Tissue weighting factors
  - Dose equivalent (equivalent dose)
  - Effective dose equivalent (effective dose)
Radiobiology and biological effects
- Relative biological effectiveness
- Cell type and radiation sensitivity
- Molecular processes
  - Direct action
  - Indirect action
  - Oxygen effect
- DNA damage
- Repair and misrepair

Models of radiation damage
- Single hit models
- Multi-hit models
- Multi-target models
- Survival curves
- Influence of radiation quality
- Stochastic effects
- Deterministic effects
- Relative and absolute risk models
- Weaknesses and uncertainties

Statistics and other mathematics
- pdf's and cdf’s
- binomial, Poisson, Gaussian
- error propagation
- pdf transforms – Monte Carlo
- linked ODE’s – Laplace transforms, STELLA, et al.
- special functions – Bessel, F1s, E1, E2, etc.; Method of Forbenius

Radioactivity transport and pathways
- Routes of entry into the body
- Routes of elimination from the body
- Biological half-times
- Systemic and metabolic models
- Bioaccumulation

Instrumentation and Measurements
- Electronics
- Counting
  - Plastic scintillators
  - Proportional counters
  - Geiger-Mueller counters
  - Gas-flow counters
  - Alpha spectrometers
  - NaI(Tl) detectors and spectrometers
  - HPGe and spectrometers
  - Pulse shape discrimination
- Dosimetry
  - Film
  - Thermoluminescence dosimetry (TLD)
  - Optically stimulated luminescence (OSL)
  - Ion chambers
  - Others
- Portable survey instruments

Operational quantities and units
- Quality factors (radiation weighting factors)
- Dose equivalent (equivalent dose)
- Effective dose
- Ambient dose equivalent

Regulations
- Guidance from ICRP and NCRP
  - Foundations for recommendations
  - Risk-based recommendations
  - Detriment and aggregated detriment
- 10CFR20 and 10CFR835 regulations
- ALARA considerations
- Radiation exposure limits
- Quality vs. energy and type – RBE review
- TEDE and other concepts
- Special definitions: Skin, lens of eye, planned special exposures, declared pregnant female, etc.
- U.S. Department of Transportation, U.S. Environmental Protection Agency and other federal agencies

Internal Dosimetry
- Stochastic and deterministic radiation effects
- Tissues at risk and tissue weighting factors
  - ICRP Publication 30
  - ICRP Publication 60
- Calculation of organ-averaged absorbed dose
- Calculation of committed dose equivalent
- Model for the respiratory system
  - ICRP Publication 30
  - ICRP Publication 66
- Model for the gastrointestinal tract
- Model for the skeleton
- Submersion in a noble gas cloud
- Metabolic models for elements
- Dose to the embryo/fetus
- Reference Man
- Limitations of approach
- Practical applications in controlling the workplace
- Practical applications in evaluating intakes

Operational Radiation Safety (e.g., from NCRP Report No. 127)
- - General guidance on establishing a program
    - Selection and training of staff
    - Responsibilities
    - Radiation safety committee
    - Training of users
  - Personnel monitoring
    - Occupationally exposed workers
    - Special exposure groups
  - Air monitoring
    - Impactors, how they operate, and how to interpret their data
    - General particle monitoring, collection by filtration
  - Radiation surveys
  - Contamination surveys
  - Area monitoring
  - Bioassay program
  - Respiratory protection
  - Environmental monitoring
  - Accident monitoring
  - Criticality monitoring
  - Record-keeping
  - Waste disposal
  - Emergency planning and response

Other topics
- Aerosol physics
  - Interpretation of aerosol properties as they apply to respiratory penetration
  - Size dependence of aerosol transport properties and implications for environmental removal or transport
- Meteorological transport
  - Use and limitations of Sutton’s equations
  - Inferring source strength from remotely measured decay product and vice versa via Sutton’s equation
- Shielding design
- Neutron dosimetry
- Space radiation
- Radioactive waste management
- Environmental radiation
  - Natural background
  - TENRE
  - NORM/NARM
- X-ray machines and accelerators
- Food irradiation
- Neutron radiography
- Radiological terrorism
- Radioactive waste management
- Space radiation