• Introduction
• Scope and Application
• Program Description
• Roles and Responsibilities
• For More Information

Introduction

Some radiation-producing machines, such as x-ray diffraction machines or particle accelerators, are capable of producing very high intensity beams which can cause acute serious injury to anyone exposed to the direct beam. For any radiation-producing machine, exposure to leakage radiation from the machine or to its scattered beam should be minimized to reduce the risk of adverse effects, such as cancer, to as low as readily achievable.

The New Jersey Department of Environmental Protection (NJDEP) regulates the possession and use of certain radiation-producing machines, including equipment intended to produce radiation, such as x-ray machines, particle accelerators and electron microscopes. Some high voltage electrical equipment which produce x-rays as an unintentional byproduct of their operation (for example, high voltage rectifiers and klystrons) are also regulated by NJDEP.

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Scope and Application

This section applies to any operations involving the following types of equipment:

1) Any machine primarily intended to produce radiation, including but not limited to:

• x-ray diffraction or x-ray fluorescence units,
• electron microscopes
• medical x-ray equipment
• x-ray radiography units
• cabinet x-ray systems
• particle accelerators
2) Any electrical equipment which is not primarily intended to produce radiation but produces radiation greater than 0.5 mrem/hour at any readily accessible point five centimeters from its surface. Any electronic tube operating at a potential above 10 kV should be considered as a possible source of x-rays even though it may not have been designed for that purpose. Such equipment may include:
• high voltage rectifiers
• transmitting tubes (such as those found in commercial and some amateur radio transmitters)
• high power amplifying tubes (e.g., klystrons and magnetrons) used to produce microwave fields

Consult with the Office of Environmental Health and Safety (EHS) if there are questions concerning the radiation-producing potential of any equipment.

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Program Description

The Princeton University Radiation Safety Manual for Laboratory Users, which is available from EHS, provides a detailed description of the program elements summarized below.

Acquiring Radiation-Producing Machines

Any proposed purchase and installation of a radiation-producing machine must be reviewed and approved in advance by EHS. EHS must also be notified in advance when any radiation-producing machine is planned to be acquired as a loan, transfer or a gift from another institution or from any individual or department at the University.

Machine Registration and Fees

NJDEP requires that radiation-producing machines which fall under the scope of its regulations must be registered. EHS will register a new machine or will update any previously registered machine’s registration with the NJDEP. NJDEP charges an initial and annual registration fee for each machine, the costs of which are borne by the department.

Exposure Monitoring

Depending on the specific type of radiation-producing machine, it may be necessary to monitor radiation exposure of workers in the vicinity of the equipment. EHS administers the radiation exposure monitoring program, provides and exchanges dosimeters, distributes radiation exposure reports, investigates any unusual radiation exposures, maintains permanent exposure records, and administers the Declared Pregnant Worker Program for the control of fetal exposure.

Radiation Surveys

EHS performs radiation surveys of any newly installed, relocated or modified equipment, and following any service that could affect the equipment’s radiological safety.

Uranium Control

Uranium, often in the form of uranyl acetate, may be used as a stain in some electron microscope procedures. Uranium is regulated somewhat differently than other radioactive materials and can be purchased directly by the user from a vendor. However, once uranium compounds are brought onto the Princeton University campus, the compounds fall within the scope of the University’s NRC radioactive material licenses. Some degree of inventory control is required and waste materials must be disposed of as radioactive waste. Contact EHS when uranium compounds are acquired.

Billing Costs

EHS, as the billing contact, distributes costs to the departments for machine registration fees and for radiation dosimeter badges.

Training

All radiation workers who use analytical x-ray equipment, such as x-ray diffraction equipment, must receive initial radiation safety training provided by EHS before working with x-ray equipment. Persons who supervise the use of x-ray machines provide supplemental training in addition to the mandatory training described above. All radiation workers must satisfy the training requirements established by their department and the x-ray machine supervisor.

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Roles and Responsibilities

Department

• Pay machine registration fees or distribute costs to appropriate principal investigators within the department.
• Notify EHS of plans to acquire, move, dispose of, modify, or make changes in responsibility for radiation-producing machines.
Supervisors
• Develop written operating procedures.
• Call EHS for radiation surveys and monitoring of any newly installed, relocated, modified machines.
• In the event of a known or possible exposure to an x-ray beam, notify EHS immediately.
• Ensure that x-ray users attend all required training.
• Conduct semiannual test of analytical x-ray machine safety systems and maintain log of safety testing.
Individual
• Be fully knowledgeable of operating procedures.
• Attend initial x-ray safety training provided by EHS.
• Use personal dosimeters, when provided.
EHS
• Review and approve each proposed acquisition of an x-ray machine.
• Register new machines with NJDEP and update registrations.
• Bill departments for initial and annual NJDEP registration fees.
• Perform radiation surveys and compliance inspections.
• Provide training to x-ray machine users.
• Contract with personal dosimetry vendor and provide personal dosimeter badges.
• Monitor and review radiation dose reports and investigate unusual radiation exposures.
• Provide consultation with pregnant workers, when requested.

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• Contact an EHS Health Physicist at 258-5294.
• An X-Ray Machine Radiation Safety Self-Audit Checklist is available through EHS or may be downloaded either as a PDF or a customizable Word document.
• The Princeton University Radiation Safety Manual is available through EHS.
• NJDEP Administrative Code, Title 7, Chapter 28.
• Links to other radiation safety-related web sites are available here.

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