MODULE 2 (Part 2) UNITS, DETECTION AND MEASUREMENT

U.S Nuclear Regulatory Commission Regulations

National Council on Radiation Protection Guidlines (NCRP)

DOSE REPORTING (2)

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS

created as an independent agency by U.S. Congress in 1974 to ensure the safe use of radioactive materials for beneficial civilian purposes while protecting people and the environment.

1974

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS created as an independent agency by U.S. Congress in ____ to ensure the safe use of radioactive materials for beneficial civilian purposes while protecting people and the environment.

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS

regulates commercial nuclear power plants and other uses of nuclear materials, such as in nuclear medicine, through licensing, inspection and enforcement of its requirements

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS

has the prime responsibility for matters concerned with the civil nuclear reactor programme.

10 CFR. Part 20 of 10 CFR

Standards for Protection against Radiation

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS

The detailed requirements are set out in Title 10, Chapter I, of the Code of Federal Regulations, known as _____, _____, sets out requirements for working with ionizing radiation, including occupational and public dose limits and also requirements for radioactive waste.

Title 10, Chapter I, of the Code of Federal Regulations

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS

The detailed requirements are set out in ____, of the ____, known as 10 CFR. Part 20 of 10 CFR, Standards for Protection against Radiation, sets out requirements for working with ionizing radiation, including occupational and public dose limits and also requirements for radioactive waste.

Atomic Energy Act

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS

Under the _____, the NRC may devolve some of its regulatory responsibilities to a state through written agreements. ‘Agreement States’ must then operate programmes that are the same or more restrictive than the NRC’s regulations.

Atomic Energy Act

U.S. NUCLEAR REGULATORY COMMISSION (NRC) REGULATIONS

However, under these agreements it is not possible for the NRC to devolve the regulation of nuclear power stations

5 rems, 0.05Sv

§20.1201 OCCUPATIONAL DOSE LIMITS FOR ADULTS

a. The total effective dose equivalent being equal to ____rem ( ___Sv)

50 rems, 0.5 Sv

§20.1201 OCCUPATIONAL DOSE LIMITS FOR ADULTS

The sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue other than the lens of the eye being equal to _____rems (___Sv)

TOTAL EFFECTIVE DOSE EQUIVALENT

the total dose of ionizing radiation an individual receives from both external and internal sources, adjusted for the biological effects of the radiation type and the tissue exposed.

TOTAL EFFECTIVE DOSE EQUIVALENT

The annual limits to the lens of the eye, to the skin of the whole body, and to the skin of the extremities, which are

External Deep=Dose Equivalent(DDE) + Committed Effective Dose Equivalent

TEDE FORMULA

External Deep-Dose Equivalent

DDE

Committed Effective Dose Equivalentt

CEDE

20 mSv (within NRC limit)

A nuclear medicine technologist received the following radiation exposures in one year:

External deep-dose equivalent (DDE): 12 mSv

Committed effective dose equivalent (CEDE): 8 mSv (from inhaled I-131)

Question: Calculate the Total Effective Dose Equivalent (TEDE) and determine if it is within the NRC annual occupational limit.

50 mSv per year

NRC occupational dose limit

COMMITTED EQUIVALENT DOSE

the equivalent dose to a specific tissue or organ (T) over a defined period of time after intake of radioactive material.

•HT(t)

equivalent dose rate to tissue T at time t.

H_T,50​=D× W_R

formula of COMMITTED EQUIVALENT DOSE

COMMITTED EQUIVALENT DOSE

In simplified terms, it’s the absorbed dose (D) in tissue T multiplied by the radiation weighting factor (WR), summed over time from intake to 50 years:

120 mSv.

COMMITTED EQUIVALENT DOSE

Example: If I-131 is inhaled and delivers 120 mSv to the thyroid, then the committed equivalent dose to the thyroid = 

1 Sv (over 50 years)

COMMITTED EQUIVALENT DOSE

A worker inhales a radionuclide (alpha particles) that delivers an absorbed dose of 0.05 Gy to the thyroid.

The committed equivalent dose to the thyroid = 

DEEP DOSE EQUIVALENT (DDE)

The dose equivalent at a tissue depth of 1 cm due to external whole-body exposure to ionizing radiation

LENS DOSE EQUIVALENT (LDE) OR EYE DOSE EQUIVALENT

The dose equivalent at a tissue depth of 0.3 cm due to external radiation

SHALLOW DOSE EQUIVALENT (SDE)

The dose equivalent at a tissue depth of 0.007 cm due to external radiation

1 cm

DEEP DOSE EQUIVALENT (DDE) -

The dose equivalent at a tissue depth of ___ due to external whole-body exposure to ionizing radiation

0.3 cm

LENS DOSE EQUIVALENT (LDE) OR EYE DOSE EQUIVALENT

- The dose equivalent at a tissue depth of ___ due to external radiation

0.007 cm

SHALLOW DOSE EQUIVALENT (SDE) -

The dose equivalent at a tissue depth of ___ due to external radiation

RADIATION DOSE MEASUREMENT DEPTHS & RADIATION TYPES

Depth:

Radiation Type:

Gamma Rays

RADIATION DOSE MEASUREMENT DEPTHS & RADIATION TYPES

Depth: Deeper Tissues & Organs

Radiation Type: (penetrate deeply)

X-rays

RADIATION DOSE MEASUREMENT DEPTHS & RADIATION TYPES

Depth: DDE 1cm

Radiation Type: (reach LDE & LDE

Beta Particles

RADIATION DOSE MEASUREMENT DEPTHS & RADIATION TYPES

Depth: LDE 0.3cm & SDE 0.007 cm

Radiation Type: (reach SDE/ shallow tissue)

Alpha Particles

RADIATION DOSE MEASUREMENT DEPTHS & RADIATION TYPES

Depth: Skin surface

Radiation Type: ( Stop at skin)

15 rems (0.15 Sv); 50 rem (0.5 Sv)

The annual limits to the lens of the eye, to the skin of the whole body, and to the skin of the extremities, which are: - A lens dose equivalent of ___ rem (___Sv) A shallow-dose equivalent of ____em (___ Sv) to the skin of the whole body or to the skin of any extremity

subtracted

Doses received in excess of the annual limits, including doses received during accidents, emergencies, and planned special exposures, must be ____ from the limits for planned special exposures that the individual may receive during the current year and during the individual's lifetime

Emergency exposure situations

Planned exposure situations

CLASSIFICATIONS OF EXPOSURE (2)

Planned exposure situations

situations in which a practice that will lead to radiation exposure is deliberately undertaken

Emergency exposure situations

Where urgent action might be needed to avoid or reduce the effects of an abnormal situation

20 mSv/year (Avg over 5ys) 50 mSv in 1 year

Up to 500 mSv; 500 mSv

Category: Worker — Whole body 

Planned Exposure Situations:__ /year ( avg over ), max __ in __

Emergency Exposure Situations: ___ (life-saving); > ___ only in extreme cases

20 mSv/year: 50 mSv in 1 yr

whole-body guidance

Category: Lens of eye

Planned Exposure Situations: ____(avg); max ___ in ___

Emergency Exposure Situations: not-specified separately, but included in ____

500 mSv/year; whole-body

Category: Skin/extremities

Planned Exposure Situations: ___

Emergency Exposure Situations: Same guidance as ___, but generally controlled

1 mSv/yr; 20-100 mSv

Category: Public—Whole body

Planned Exposure Situations: ___

Emergency Exposure Situations: ___ (reference level, short-term)

Internal and External Doses

Prior to permitting an individual to participate in a planned special exposure, the licensee shall determine -

(a) The ___and _____ from all previous planned special exposures;

§20.1502; occupational radiation dose

DETERMINATION OF PRIOR OCCUPATIONAL DOSE

For each individual who is likely to receive an annual occupational dose requiring monitoring under ___, the licensee shall determine the ____ received during the current year.

All doses

DETERMINATION OF PRIOR OCCUPATIONAL DOSE

Prior to permitting an individual to participate in a planned special exposure, the licensee shall determine -

____ in excess of the limits (including doses received during accidents and emergencies) received during the lifetime of the individual.

individual's dose equivalent(s)

DETERMINATION OF PRIOR OCCUPATIONAL DOSE

Obtain reports of the ____from the most recent employer for work involving radiation exposure, or the individual's current employer.

exposure history; 

DETERMINATION OF PRIOR OCCUPATIONAL DOSE

The licensee shall record the ____ of each individual. The form or record must show each period in which the individual received occupational exposure to radiation or radioactive material and must be signed by the individual who received the exposure.

§20.1201

DETERMINATION OF PRIOR OCCUPATIONAL DOSE

If the licensee is unable to obtain a complete record of an individual's current and previously accumulated occupational dose, the licensee shall assume- in establishing administrative controls under ___

1.25 rems (12.3 mSv)

DETERMINATION OF PRIOR OCCUPATIONAL DOSE

or the current year, that the allowable dose limit for the individual is reduced by ___rems (___ mSv) for each quarter for which records were unavailable and the individual was engaged in activities that could have resulted in occupational radiation exposure

planned special exposures

DETERMINATION OF PRIOR OCCUPATIONAL DOSE

f the licensee is unable to obtain a complete record of an individual's current and previously accumulated occupational dose, the licensee shall assume- in establishing administrative controls under §20.1201 (Occupational dose limits for adults)

b. That the individual is not available for _____

0 mSv

50 mSv

Missing Quarters: 0 (all records available)

Reduction:

New Allowable Limit:

12.5 mSv

37.5 mSv

Missing Quarters: 1

Reduction:

New Allowable Limit:

25 mSv

25 mSv

Missing Quarters: 2

Reduction:

New Allowable Limit:

37.5 mSv

12.5 mSv

Missing Quarters: 3

Reduction:

New Allowable Limit:

50 mSv

0 mSv

Missing Quarters: 4 (no records at all)

Reduction:

New Allowable Limit:

25 mSv

A RT is newly hired in July but no dose records are available from Jan-June (2 quarters). NRC will assume possible prior exposure for those 2 quarters. What is the allowable dose for the rest of the year? 

33 mSv > 25 mSv → exceeds the adjusted allowable limit

A radiologic technologist is newly hired in July. No dose records are available for Jan–June (2 quarters). During the year the worker receives: DDE = 28 mSv and CEDE = 5 mSv. What is the adjusted allowable annual limit the employer must use? (Use 12.5 mSv reduction per missing quarter.) Compute TEDE and say whether it exceeds the adjusted allowable limit.

§ 20.1502

RECORDS OF INDIVIDUAL MONITORING RESULTS

Recordkeeping requirement. Each licensee shall maintain records of doses received by all individuals for whom monitoring was required pursuant to ___ (Conditions requiring individual monitoring of external and internal occupational dose), and records of doses received during planned special exposures, accidents, and emergency conditions. These records must include, when applicable—

COMMITTED EFFECTIVE DOSE (E₅₀)

the effective dose integrated over a period of 50 years (for adults) or up to age 70 (for children), following the intake of radioactive material

50 years

70

COMMITTED EFFECTIVE DOSE (E₅₀)

the effective dose integrated over a period of ___ (for adults) or up to age ___ (for children), following the intake of radioactive material

internal dosimetry

inhalation, ingestion, or absorption of radionuclides

COMMITTED EFFECTIVE DOSE (E₅₀)

used in internal dosimetry (inhalation, ingestion, or absorption of radionuclides)

COMMITTED EFFECTIVE DOSE (E₅₀)

used in regulatory dose limits (e.g., in TEDE calculations)

4.8 mSv

If the thyroid receives a committed equivalent dose of 120 mSv and the tissue weighting factor for the thyroid is 0.04. What is the COMMITTED EFFECTIVE DOSE (E₅₀)?

0.048 Sv or 48 mSv

§20.1204

§ 20.1502

The specific information used to assess the committed effective dose equivalent pursuant to ___ (Determination of internal exposure), and when required by ___ ( Conditions requiring individual monitoring of external and internal occupational dose)

§20.1202

The total effective dose equivalent when required by __ (Compliance with requirements for summation of external and internal doses).

Recordkeeping frequency

The licensee shall make entries of the records at least annually.

Recordkeeping format

The licensee shall maintain in clear and legible records containing all the information required by NRC Form 5 (Occupational Dose Record for a Monitoring Period)

Privacy protection

The records required should be protected from public disclosure because of their personal privacy nature.

embryo/fetus

The licensee shall maintain the records of dose to an  ____ with the records of dose to the declared pregnant woman

required form or record

The licensee shall retain the___until the Commission terminates each pertinent license requiring this record

§20.1301

RECORDS OF DOSE TO INDIVIDUAL MEMBERS OF THE PUBLIC

Each licensee shall maintain records sufficient to demonstrate compliance with the dose limit for individual members of the public 

§§20.2002

RECORDS OF DOSE TO INDIVIDUAL MEMBERS OF THE PUBLIC

Each licensee shall maintain records of the disposal of licensed materials made under ___ (Method for obtaining approval of proposed disposal procedures)

§§20.2003

RECORDS OF DOSE TO INDIVIDUAL MEMBERS OF THE PUBLIC

Disposal by release into sanitary sewerage

§§20.2004

RECORDS OF DOSE TO INDIVIDUAL MEMBERS OF THE PUBLIC

Treatment or disposal by incineration

20.2005

RECORDS OF DOSE TO INDIVIDUAL MEMBERS OF THE PUBLIC

Disposal of specific wastes. 10 CFR part 61

terminates

RECORDS OF DOSE TO INDIVIDUAL MEMBERS OF THE PUBLIC

The licensee shall retain the records until the Commission____ each pertinent license requiring the record.

inhalation; internal dose

consumption

Radiation exposure of the population in a number of ways:

____ of radioactive materials resulting in ___;

____ of foodstuffs (e.g. vegetables) contaminated by deposition; and

consumption of meat or milk from animals which have grazed on contaminated ground.

Potassium Iodide (KI)

a stable (non-radioactive) iodine salt

Potassium Iodide (KI)

commonly used in medicine, nutrition, and radiation protection

1,000

appendix C; part 20

Telephone reports

Immediately after its occurrence becomes known to the licensee, any lost, stolen, or missing licensed material in an aggregate quantity equal to or greater than ___ times the quantity specified in ___ to ___ (Quantities of Licensed Material Requiring Labeling) under such circumstances that it appears to the licensee that an exposure could result to persons in unrestricted areas

1,000

Radionuclide: Technetium-99m

Quantity (µCi):

10

Radionuclide: Cesium-137

Quantity (µCi):

1

Radionuclide: Iridium-192

Quantity (µCi):

1

Radionuclide: Iodine-131

Quantity (µCi):

30; appendix C to part 20

Within ____ days after the occurrence of any lost, stolen, or missing licensed material becomes known to the licensee, all licensed material in a quantity greater than 10 times the quantity specified in ___ to ___ (Quantities of Licensed Material Requiring Labeling) that is still missing at this time reports must be made .

Emergency Notification System; NRC Operations Center

Reports must be made as follows:

Licensees having an installed ____ shall make the reports to the ____

NRC Headquarters Operations

Reports must be made as follows:

All other licensees shall make reports by telephone to the ____ Center at the numbers specified in.

EMERGENCY NOTIFICATION SYSTEM (ENS)

A telephone system used by the NRC to receive notifications of significant nuclear events with an actual or potential effect on the health and safety of the public.

25 rems (0.25 Sv)

NOTIFICATION OF INCIDENTS

Immediate Notification

1. An individual to receive—

a. A total effective dose equivalent of ___ rems (___ Sv) or more; or

75 rems ( 0.75 Sv)

NOTIFICATION OF INCIDENTS

Immediate Notification

A lens dose equivalent of ___

250 rads (2.5 Gy)

NOTIFICATION OF INCIDENTS

Immediate Notification

shallow-dose equivalent to the skin or extremities of ____

5 rems (0.05 Sv)

NOTIFICATION OF INCIDENTS

24-hour notification

A total effective dose equivalent exceeding ___

15 rems (0.15 Sv)

NOTIFICATION OF INCIDENTS

24-hour notification

A lens dose equivalent exceeding

50 rems (0.5 Sv)

NOTIFICATION OF INCIDENTS

24-hour notification

shallow-dose equivalent to the skin or extremities exceeding 

Total effective dose equivalent (TEDE)

the sum of the effective dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures)