REVIEW:

1) Since all exposure to radiation is thought to cause some negative biological effects, the ALARA principle is designed to the risk from exposure by keeping exposures ALARA.

2) ALARA stands for

Although the individual radiation worker is ultimately responsible for maintaining his/her radiation dose ALARA, management and Radiological Control Personnel also play an important role in the ALARA program. The following are some of the responsibilities of the three groups:

Management

TJNAF management's responsibilities include:

• Implementing policies and procedures to maintain radiation exposures ALARA.
• Establish radiation exposure goals and guidelines.
• Communicate radiological goals to all personnel through line management.
• Track and evaluate radiological performance.
• Provide a feedback mechanism for reporting performance and implementing improvements and corrective actions.

Radiological Control Personnel

The Radiological Control Group at TJNAF is responsible for:

• Implementing radiological requirements, limits, guidelines, and procedures.
• Monitoring radiological work in progress to ensure radiologically safe practices are used.
• Measuring, documenting, and tracking personnel exposures and environmental impact of radiological work.
• Evaluating radiological performance and advising TJNAF management in implementing improvements.

Radiological workers

Each radiological worker is responsible for:

• Knowing and minimizing his/her exposure.
• Complying with all radiological rules and written and oral instructions from Radiological Control Personnel.
• Being familiar with emergency procedures.
• Being alert for and responding to unusual radiological situations.
• Knowing where/how to contact Radiological Control Personnel in your work area.

6.3 DOSE REDUCTION PRACTICES

The main goal of the ALARA program is to reduce both the external and internal radiation doses to a level that is As Low As Reasonably Achievable.

The three basic protective measures used to reduce external exposure are:

• minimizing time in a field of radiation
  
  
• maximizing the distance from a source of radiation
  
  
• using shielding whenever possible

Methods for minimizing time:

• Pre-plan and discuss the task thoroughly prior to entering the area.
  Use only the number of workers actually required to do the job.
  
  
• Have all necessary tools before entering the area.
  
  
• Use mock ups and practice runs.
  
  
• Take the most direct route to the job site.
  
  
• Never loiter in an area controlled for radiological purposes.
  
  
• Work efficiently but swiftly.
  
  
• Do the job right the first time.
  
  
• Perform as much work outside the area as possible.

Methods for maintaining distance from sources of radiation:

• The worker should stay as far away as possible from the source of radiation.
  
  
• For point sources, the dose rate follows the inverse square law. If you double the distance, the dose rate falls to 1/4. If you triple the distance, the dose rate falls to 1/9.
  
  
• Be familiar with radiological conditions in the area.
  
  
• During work delays, move to lower dose rate areas.
  
  
• Use remote handling devices when possible.

Proper uses of shielding:

• Shielding reduces the amount of radiation dose to the worker. Different materials shield a worker from the different types of radiation.
  
  
• Use permanent shielding such as non-radiological equipment/structures.
  
  
• Use shielded containment (e.g., glove boxes, etc.) when available.

• Wear safety glasses/goggles to protect the eyes from beta radiation, when applicable.
  
  
• It should be remembered that the placement of shielding my actually increase the total dose (e.g., man-hours involved in placement, Bremsstrahlung, etc.).
  
  
• Temporary shielding (e.g. lead or concrete blocks) can only be installed when procedures are used. Once temporary shielding is installed, it cannot be removed without proper authorization.

Additional methods to reduce dose:

Source reduction is another method of reducing radiation doses. Source reduction normally involves procedures such as flushing radioactive systems, decontamination, etc. to reduce the amount of radioactive materials present in/on a system that contribute to radiation levels in an area. Additionally, the production of radioactive materials may be reduced through careful selection of materials used in and around activation sources and by practicing good housekeeping in radiological areas to prevent inadvertent activation or contamination of materials.

We will be looking at ALARA work practices and exposure controls more in subsequent units.

REVIEW:

4) Who should establish radiological goals and policies, and communicate these to TJNAF personnel?

1. The RadCon group
2. The first line supervisor
3. The DOE
4. TJNAF management

5) Who is responsible for keeping your dose ALARA ?

To implement ALARA, the basic controlling principles are , , and .

9) You can help minimize radioactive waste production by: .