Radiation monitoring and contamination control are crucial for safety in radioactive environments. These practices involve using specialized equipment like Geiger-Müller counters and personal dosimeters to detect and measure radiation levels.

Contamination control techniques, including wipe tests and decontamination procedures, help prevent the spread of radioactive materials. These methods, along with proper barriers and air sampling, ensure a safe working environment in radiochemistry labs and nuclear facilities.

Radiation Detection and Monitoring

Geiger-Müller Counters and Scintillation Detectors

• Geiger-Müller (GM) counters detect ionizing radiation by measuring electrical pulses produced when radiation interacts with the GM tube
• GM counters are widely used for detecting and measuring alpha, beta, and gamma radiation
• Scintillation detectors use materials that emit light when exposed to ionizing radiation (scintillators)
• Scintillation detectors are more sensitive than GM counters and can distinguish between different types and energies of radiation
• Common scintillator materials include sodium iodide (NaI) and bismuth germanate (BGO)
• Scintillation detectors are often used for gamma spectroscopy and environmental monitoring

Personal Dosimeters and Area Monitoring

• Personal dosimeters measure an individual's exposure to ionizing radiation over a period of time
• Examples of personal dosimeters include film badges, thermoluminescent dosimeters (TLDs), and optically stimulated luminescence (OSL) dosimeters
• Personal dosimeters are worn by workers in radiation environments to ensure exposure limits are not exceeded
• Area monitoring involves measuring radiation levels in a specific location or area
• Area monitoring is used to assess the effectiveness of shielding, identify potential radiation hazards, and ensure compliance with regulations
• Examples of area monitoring devices include survey meters, area dosimeters, and continuous air monitors (CAMs)

Radiation Surveys

• Radiation surveys are systematic measurements of radiation levels and contamination in a specific area or facility
• Surveys are conducted to identify and quantify radiation sources, assess potential hazards, and ensure compliance with regulations
• Types of radiation surveys include:
  • Contamination surveys: measure the presence and extent of radioactive contamination on surfaces
  • Dose rate surveys: measure the radiation dose rate at various locations
  • Airborne radioactivity surveys: assess the concentration of radioactive materials in the air
• Radiation surveys are performed using various instruments, such as GM counters, scintillation detectors, and specialized survey meters
• Survey results are documented and used to develop radiation protection plans and procedures

Contamination Control

Wipe Tests and Decontamination Procedures

• Wipe tests are used to detect and measure removable radioactive contamination on surfaces
• A wipe test involves rubbing a filter paper or swab over a surface and measuring the radioactivity collected on the wipe
• Wipe test results are compared to established limits to determine if decontamination is necessary
• Decontamination procedures involve removing or reducing radioactive contamination from surfaces, equipment, or personnel
• Decontamination methods include:
  • Physical removal (wiping, brushing, or vacuuming)
  • Chemical decontamination (using solvents or detergents)
  • Decay in storage (allowing short-lived radionuclides to decay)
• Decontamination procedures are specific to the type of contamination and the surface or material being decontaminated

Contamination Barriers and Air Sampling

• Contamination barriers are used to prevent the spread of radioactive contamination
• Examples of contamination barriers include:
  • Protective clothing (lab coats, gloves, and shoe covers)
  • Containment enclosures (glove boxes and fume hoods)
  • Absorbent materials (spill trays and drip pans)
• Proper use of contamination barriers helps minimize the risk of personnel contamination and the spread of contamination to uncontrolled areas
• Air sampling is used to assess the concentration of radioactive materials in the air
• Air sampling is important for detecting and monitoring airborne radioactivity, which can pose an inhalation hazard
• Types of air samplers include:
  • Continuous air monitors (CAMs): provide real-time measurement of airborne radioactivity
  • Grab samplers: collect a single air sample over a short period
  • Personal air samplers: worn by workers to assess individual exposure to airborne radioactivity
• Air sampling results are used to determine the need for respiratory protection and to assess the effectiveness of ventilation and containment systems