Radiation Safety and Regulations

  1. To begin with we need to review some of your radiation units - see below
  2. Then we will go over NRC regulations and definitions
  3. We will also take an in-depth look at how the NRC classifies radiation exposure levels, note the maximum limits to each, and review some (but not all of) the regulations that govern safe radiation practice
  4. .  Specifically, 10CFR Parts 19, 20 and 35
  5. In order to apply the appropriate conversions you will need to also remember your prefixes

Prefixes

yotta (Y)

1 000 000 000 000 000 000 000 000

1024

zetta (Z)

1 000 000 000 000 000 000 000

1021

exa (E)

1 000 000 000 000 000 000

1018

peta (P)

1 000 000 000 000 000

1015

tera (T)

1 000 000 000 000

1012

giga (G

1 000 000 000

109

Mega (M)

1 000 000

106

kilo (k)

1 000

103

hecto (h)

100

102

deca (da)

10

101

1

1

1

deci (di)

0.1

10-1

centi (c)

0.01

10-2

milli (m)

0.001

10-3

micro (µ)

0.000 001

10-6

nano (n)

0.000 000 001

10-9

pico (p)

0.000 000 000 001

10-12

femto (f)

0.000 000 000 000 001

10-15

alto (a)

0.000 000 000 000 000 001

10-18

zepto (z)

0.000 000 000 000 000 000 001

10-21

yocto (y)

0.000 000 000 000 000 000 000 001

10-24

10 CFR Part 1 – Notices, Instructions And Reports To Workers: Inspection And Investigations

http://www.nrc.gov/reading-rm/doc-collections/cfr/part019/index.html

Comments regarding Part 19

10 CFR Part 20 – Standards For Protection Against Radiation

http://www.nrc.gov/reading-rm/doc-collections/cfr/part020/index.html

Comments regarding Part 20

Parts of Subpart A - General Provisions

English Unit SI Unit

Roentgen (R) = 2.58 * 10^-4 C/kg (coulomb per kilogram)

Coulomb/kg^-1 (C/kg)

RAD = 1 erg/gm

Gray (Gy) = 100 ergs

RBE=Dose in rad to produce same effect with x or gamma ray/
Dose in rad to produce same effect with radiation under investigation

none

REM = RBE*RAD

Sievert (Sv) = 100 REM

Curie to Becquerel Conversion

1 dps is one disintegration per second

1 Becquerel (Bq) = 1 dps

1 Curie (Ci) = 3.7 x 1010 dps

37 GBq

1 Ci = 2.2 x 1012 dpm (2.2 x 10) / 60 = 0.0367 or 3.67 x 10-2

37 GBq

1 mCi

37 MBq

20 mCi (20 x 3.7 x 107 dps) = 74 x 107 =

740 MBq or 0.74 GBq

Subpart B - Radiation Protection Programs

Parts of Subpart C - Occupational Dose Limits

Annual Occupational Exposure Limits

Dose – ENG

Dose - SI

Total Effective Dose Equivalent (TEDE)

5 rem

0.05 Sv

Dose Equivalent to the Eye (LDE)

15 rem

0.15 Sv

Shallow Dose Equivalent to skin, extremities (SDE)

50 rem

0.5 Sv

TEDE to any other individual organ or
Single organ dose (TODE) other than the eye

50 rem 0.5 Sv

TEDE to embryo/fetus of declared pregnant woman

0.5 rem

0.005Sv

Minors

10% of an adult

10% of an adult dose

Members of the Public

0.1 rem

0.001 Sv

Derived air concentration (DAC) and
annual limit on intake (ALI)

Part 20 Appendix B, Table 1

Part 20 Appendix B, Table 1

Parts of Subpart D - Radiation Dose Limits for Individual Members of the Public

Who should be monitored? (Regulatory Guide 8.7.C.1.2) Any individual who will exceed 10% of an applicable limit

No Parts to Subpart E - Radiological Criteria for License Termination

Part of Subpart F - Surveys and Monitoring

Subpart G  - Control of Exposure From External Sources in Restricted Areas

No Parts of Subpart H - Respiratory Protection and Controls to Restrict Internal Exposure in Restricted Areas

Part of Subpart I - Storage and Control of Licensed Material

Parts of Subpart J - Precautionary Procedures

Parts of Subpart K - Waste Disposal

Appendix C to Part 20--Quantities of Licensed Material Requiring Labeling

Appendix G to Part 20--Requirements for Transfers of Low-Level Radioactive Waste Intended for Disposal at Licensed Land Disposal Facilities and Manifests

Parts of Subpart L - Records

Parts of Subpart M - discusses revisions to records that must be maintained

Subpart O Discusses Enforcement and Penalties

Medical Use Of Byproduct Material – 10 CFR 35

http://www.nrc.gov/reading-rm/doc-collections/cfr/part035/index.html

General technical requirements include, but not limited to:

It should be noted that in order to have a viable nuclear medicine facility there are two requirements that must be met:

  1. The facility must have a radioactive material license (specific or broad)
  2. The physician must be on the license and he/she has to be approved for any or all of 10 CFR Parts 35.100, 200, 300, 400, 500, 600
  3. The specific Parts are noted below

Specific issues related to 10 CFR 35:

Subpart D--Unsealed Byproduct Material--Written Directive Not Required

35.100 Use of unsealed byproduct material for uptake, dilution, and excretion studies.

35.200 Use of unsealed by product material for imaging and localization studies.

Subpart E--Unsealed Byproduct Material--Written Directive Required

35.300 Use of unsealed by product material for therapeutic administration.

Subpart F--Manual Brachytherapy

35.400 Use of sources for brachytherapy.

Subpart G--Sealed Sources for Diagnosis

35.500 Use of sealed sources for diagnosis.

Subpart H--Photon Emitting Remote Afterloader Units, Teletherapy Units, and Gamma Stereotactic Radiosurgery Units

35.600 Use of a sealed source in a teletherapy unit.

All subparts are linked to Part 35 - scroll to the end of the document

Subpart J -- Training and Experience Requirements

Subpart L--Records

Subpart M--Reports

Subpart N--Enforcement

As you can see there are many requirements (laws) identified by the NRC when it comes to handling radiation! The rationale for all of this is to protect not just you, the radiation worker, but also the general public. Failure to comply with these rules and regulations may result in you or your facility to be fined and in extreme situations the penalty could include the inability to ever work in nuclear medicine or even time spent behind bars.

Always consider proper and safe radiation practices wherever you work, your loved ones depend on it!

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