NRC 10 CFR

NRC 10 CFR Part 20: Standards for Protection Against Radiation

Definitions

Radiation symbol

  • Radiation Area: an area, accessible to individuals, in which radiation levels could result in an individual receiving a dose equivalent in excess of 0.005 rem (0.05 mSv) in 1 hour at 30 centimeters from the radiation source or from any surface that the radiation penetrates.
  • High Radiation Area: an area, accessible to individuals, in which radiation levels from radiation sources external to the body could result in an individual receiving a dose equivalent in excess of 0.1 rem (1 mSv) in 1 hour at 30 centimeters from the radiation source or 30 centimeters from any surface that the radiation penetrates.
  • Very High Radiation Area: an area, accessible to individuals, in which radiation levels from radiation sources external to the body could result in an individual receiving an absorbed dose in excess of 500 rads (5 grays) in 1 hour at 1 meter from a radiation source or 1 meter from any surface that the radiation penetrates.

Radiation protection program requirements

  • Implement a radiation protection program commensurate with the scope of licensee activities
  • Use procedures and engineering controls to achieve occupational and public doses which are As Low As is Reasonably Achievable (ALARA)
  • At least annually review radiation protection policies
  • Report events which exceed dose limits
  • Restrict access to High and Very High Radiation Areas
  • Manage individual respiratory protection equipment
  • Secure stored materials
  • Post caution and danger signs in radiation areas of all levels
  • Label radiation sources and containers
  • Inspect and survey packages containing radiation sources upon receipt
  • Proper disposal of radiation materials
  • Maintain records of radiation protection program
    • Surveys
    • Individual monitored doses both workers and public
    • Planned exposures
    • Received radiation sources
    • Waste disposal
  • Reporting of events which exceed dose limits

Dose Limits

Type Annual Occupational Limit (Adults)Annual Occupational Limit (Minors)

 

10% of Adult Limit

Embryo/Fetus

 

For “declared” pregnant woman during entire pregnancy

Members of Public
Total Effective Dose5 rem (50 mSv)0.5 rem (5 mSv)0.5 rem (5 mSv)0.1 rem (1 mSv); Per Year

 

0.002 rem (0.02 mSv); dose per hour in unrestricted areas

0.5 rem (5 mSv); Pear Year (visitors/infrequent)

Individual Organ Excluding Lens50 rem (500 mSv)5 rem (50 mSv)  
Lens 15 rem (150 mSv)1.5 rem (15 mSv)  
Skin50 rem (500 mSv)5 rem (50 mSv)  

Planned Special Exposures

A licensee may authorize an adult worker to receive doses in addition to the annual dose limits provided that a number of conditions are met.

Surveys and Monitoring

NRC 10 CFR Part 20 requires that sites survey areas which may have non-background radiation present. Additionally, personnel meeting the following criteria must be monitored:

  • Adults likely to receive more than 10% of their annual exposure limits
  • Minors likely to receive more than 0.1 rem (1mSv) deep dose, 0.15 rem (1.5 mSv) lens dose, or 0.5 rem (5 mSv) dose to skin or extremities
  • Declared pregnant women likely to receive more than 0.1 rem (1 mSv)
  • Any individual entering a high or very high radiation area

NRC 10 CFR Part 35: Medical Use of Byproduct Materials

Map of agreement and non-agreement states. Source: U.S.NRC
Map of agreement states (orange) and non-agreement states (yellow). Source: U.S.NRC

Definitions

Agreement State

Any State with which have entered into agreements with NRC that give them [the states] the authority to license and inspect byproduct, source, or special nuclear materials used or possessed within their borders.

Authorized User

A physician, dentist, or podiatrist meeting certain educational criteria who is authorized to permit the medical use of byproduct material.

Radiation Safety Officer (RSO)

An RSO is responsible for implementing the radiation protection program.

Radiation Safety Committee

The radiation safety committee oversees the use of byproduct material. It must include the RSO, and authorized user, a nurse, and a representative of management.

Written Procedures

The licensee must develop, implement, and maintain written procedures for medical uses that require a written directive. These procedures must include:

  • Identifying with high confidence the patient’s identify prior to each administration
  • Verifying that each administration is given as per the written directive
  • Verifying dose calculations
  • Verifying that computer generated dose calculations are correctly transferred to the consoles of therapeutic medical units

Written Directives

A written directive is an authorized user’s written order for the administration of byproduct material or radiation from byproduct material to a specific patient or human research subject. There are exceptions to the requirement of a written directive when it would jeopardize patient’s health. Written directives must contain the following:

ProcedureWritten Directive Requirements
Administration of greater than 1.11 MBq (30 μCi) of sodium iodide I-131
  • Patient name
  • Doseage
Administration of a therapeutic dosage of unsealed byproduct material other than sodium iodide I-131
  • Patient name
  • Radioactive drug
  • doseage
  • route of administration
Gamma Stereotactic Radiosurgery
  • Patient name
  • Total Dosage
  • Treatment site
  • Values for target per treatment
Teletherapy
  • Patient name
  • Dose per fraction
  • Number of fractions
  • Treatment site
High Dose Rate Brachytherapy
  • Patient name
  • Radionuclide
  • Treatment site
  • Dose per fraction
  • Number of fractions
  • Total dose
All Other Brachytherapy
  • Before implantation
    • Patient name
    • Treatment site
    • Radionuclide
    • Dose
  • After implantation but before completion
    • Patient name
    • Radionuclide
    • Treatment Site
    • Number of sources
    • Source strength
    • Exposure time or total dose

Medical Event

A medical event (formerly called a misadministration or recordable event) is an event not caused by patient intervention meeting any of the following criteria:

  •  Dose delivered differs from the prescribed dose by more than 50mSv (5 rem) effective dose equivalent, 500 mSv (50 rem) to an organ or tissue, AND one of the following
    • total dose differs by more than 20% from prescription
    • dose from a single fraction varies by more than 50%
  • A dose exceeding 50mSv (5 rem) effective dose equivalent, 500 mSv (50 rem) to an organ or tissue arising from any of the following
    • Administration of wrong radioactive drug
    • Administration of radioactive drug by wrong route of administration
    • Administration of a dose to wrong individual
    • Administration of dose by the wrong mode of treatment
    • A leaking source
  • A dose to the skin or an organ or tissue other than the treatment site which exceeds 500 mSv (50 rem) to an organ or tissue AND differs by 50% or more from expected dose

NRC 10 CFR Part 37: Physical Protection of Category 1 and 2 Quantities of Radioactive Material

Source categories

The source categorization used in NRC 10 CFR Part 37 originates from the International Atomic Energy Agency (IAEA) Safety Standards Series No RS-G-1.9. The 5 source categories are based on their potential for harm if not properly handled.

Category 1 Source: Personally Extremely Dangerous

The amount of radioactive material, if not safely managed or securely protected would be likely to cause permanent injury to a person who handled it, or wher otherwise in contact with it, for more than a few minutes. It would probably be fatal to be close to this amount of unshielded material for a period of a few minutes to an hour.

Category 2 Source: Personally Very Dangerous

The amount of radioactive material, if not safely managed or securely protected, could cause permanent injury to a person who handled it, or were otherwise in contact with it, for a short time (minutes to hours). It could possibly be fatal to be close to this amount of unshielded radioactive material for a period of hours to days.

Category 3 Source: Personally Dangerous

This amount of radioactive material, if not safely managed or securely protected, could cause permanent injury to a person who handled it, or were otherwise in contact with it, for some hours. It could possibly – although it is unlikely – be fatal to be close to this amount of unshielded radioactive material for a period of days to weeks.

Category 4 Source: Unlikely to be Dangerous

It is very unlikely that anyone would be permanently injured by this amount of radioactive material. However, this amount of unshielded radioactive material, if not safely managed or securely protected, could possibly – although it is unlikely – temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks.

Category 5 Source: Not Dangerous

No one could be permanently injured by this amount of radioactive material.

CategoryCommon Example
1
  • Teletherapy sources
  • Fixed, multi-beam teletherapy
  • Irradiators
  • Radioisotope thermoelectric generators
2
  • High/medium dose rate brachytherapy
  • Industrial gamma radiography
3
  • Fixed industrial gauges
4
  • Low dose rate brachytherapy (except eye plaques and permanent implant sources)
  • Bone densitometers
  • Static eliminators
5
  • Low dose rate brachytherapy eye plaques and permanent implant sources
  • X-ray fluorescence devices
  • Positron Emission Tomography
  • Electron Capture Devices
  • Mossbauer spectrometry
Radioactive MaterialCategory 1Category 2
Americium-241 60 TBq (1,620 Ci)0.6 TBq (16.2 Ci)
Americium-241/Be60 TBq (1.620 Ci)06 TBq (16.2 Ci)
Californium-25220 TBq (540 Ci)0.2 TBq (5.40 Ci)
Cobalt-6030 TBq (810 Ci)0.2 TBq (8.10 Ci)
Curium-24450 TBq (1,350 Ci)0.5 TBq (13.5 Ci)
Cesium-137100 TBq (2,700 Ci)1 TBq (27.0 Ci)
Gadolinium-1531,000 TBq (27,000 Ci)10TBq (270 Ci)
Iridium-19280 TBq (2,160 Ci)0.8 TBq (21.6 Ci)
Plutonium-23860 TBq (1,620 Ci)0.6 TBq (16.2 Ci)
Plutonium-239/Be60 TBq (1,620 Ci)0.6 TBq (16.2 Ci)
Promethium-14740,000 TBq (1,080,000 Ci)400 TBq (10,800 Ci)
Radium-22640 TBq (1,080 Ci)0.4 TBq (10.8 Ci)
Selenium-75200 TBq (5,400 Ci)2 TBq (54 Ci)
Strontium-901,000 TBq (27,000 Ci)10 TBq (270 Ci)
Thulium-17020,000 TBq (540,000 Ci)200 TBq (5,400 Ci)
Ytterbium-169300 TBq (8,100 Ci)3 TBq (81.0 Ci)

Access Authorization Requirements

  • Limit access to authorize individuals
  • Requires background investigation initially and every 10 years
    • Criminal history
    • Fingerprinting
    • Credit history check
    • Work history
    • Character and reputation evaluation
  • Escorted individuals do not need background investigation

Physical Protection Requirements

  • Security plan
  • Procedures
  • Training
  • Protection of Information
  • Coordination with local law enforcement agency (LLEA)
  • Establish security zones
  • Annual program review
  • Report any threats to material

Related Pages

Click here to read NRC 10 CFR.

Click here to read IAEA Safety Standards Series No. RS-G-1.9

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