Biological effects of radiation

Question 1

Define Roentgen

Answer 1

(R) measure of the ionization produced in air by X-ray or gamma radiation. 1R is the amount of X-ray or gamma radiation producing 1 electrostatic unit of charge in one cc of dry air at STP.

Question 2

Define RAD (Radiation Absorbed Dose

Answer 2

a measure of the absorbed dose of any ionizing radiation in terms of energy absorbed per unit mass 1 RAD = 100 ergs per gram of material

Question 3

Define REM (Roentgen Equivalent Man)

Answer 3

Dose equivalent REM = Rad x Quality Factor

Question 4

State Quality Factor Values for Beta, Gamma, Alpha. Fast Neutron, Thermal Neutron

Answer 4

• Alpha- 20
• Fast Neutron- 10
• Thermal Neutron- 2
• Beta & Gamma- 1

Question 5

Classify internal and external radiations

Answer 5

External

• Gamma
• Neutron

Internal (Ingestion)

• Alpha
• Beta

Question 6

Describe Direct Cellular Damage

Answer 6

radiation interacts with an important molecule (DNA) causing a change or break in the molecule. Could result in mutated cell as it reproduces.

Question 7

Describe indirect cellular damage

Answer 7

radiation interacts with a molecule in the cytoplasm of the cell which results in the formation of ions or radicals which could react with important molecules of the cell resulting in permanent damage

Question 8

Rank tissues by radiosensitivity

Answer 8

1. Lymphoid
2. Immature Blood Cells
3. Gastro Intestinal Cells
4. Gonads
5. Skin
6. Blood Vessels
7. Liver & Adrenal Cells
8. Bone
9. Muscle
10. Nerve Cells

Question 9

State the stages of Radiation Syndrome

Answer 9

1. Radiation Illness
2. Apparent Recovery
3. True Illness
4. Death or Recovery

Question 10

Describe production of Tritium

Answer 10

• Ternary Fission- (3 fragments) produces more tritium than other sources in light water reactor. Main source is in fuel rod.
• Soluble Boron production- Neutron absorption of boron produces tritium.
• Soluble Lithium Reactions-

Question 11

Describe where tritium is likely to be found

Answer 11

• Containment- Largest inventory of RCS in the plant where tritium is produced
• Spent Fuel Pit/ Refueling Water- Made up mostly of borated RCS coolant
• Limiting 3.5 microcuries per gram in RCS coolant along with purges of containment atmosphere should preclude need for protective equipment in containment