1. Nuclear Energy Radiation

2. What is a Radioactive Element? Radioactive elements have a nucleus that is unstable. It decays or breaks apart releasing energy in the process. Half-Life is the amount of time it takes for 1/2 of a group of nuclei to decay. example: 14C half-life is 5730 years

3. What happens when the body is exposed to radioactive elements? Body treats radioactive nuclei the same as stable nuclei ex: Ca ingested by the body whether radioactive or not is sent to the bones. Radiation may enter body by: Inhalation Ingestion Dermally

4. Which avenue do you think is the most dangerous? Inhalation, Why?

5. TYPES OF RADIATION Alpha radiation(α) Helium nuclei (+) Dangerous inside our bodies, can be stopped by a sheet of paper or skin. Damages cells, beginning of cancer.

6. TYPES OF RADIATION Beta radiation (β) Electrons emitted with high energy. Equally as dangerous as alpha radiation inside our bodies, can be stopped by 1 piece of Aluminum foil.

7. TYPES OF RADIATION Gamma radiation( γ ) very high energy electromagnetic radiation. Penetrates bodies more so than X-rays. Need at least 6 inches of lead to stop. Size of human genes, so it can easily cause mutations.

8. What are Positive uses of Radiation? 1.Radiation treatment for cancer 2.X-rays 3.Nuclear medicine 4.Nuclear power 5.Other?

9. MEASUREMENT OF RADIATION Millirems(mr) is a measurement of “whole body” exposure to radiation. A Millirems is a certain # of tracks/gram of human tissue. Measures amount of damage done.

10. Natural Background radiation (per year)* Natural Background radiation (per year)* Cosmic rays35 mr Air 5 mr Building materials34 mr Food25 mr Ground11 mr 110 mr

11. Man-made radiation* Coast to coast jet flight5 mr/round trip Color TV1 mr/year X-ray diagnosis 50 mr/exposure Weapons fall-out4 mr/year Living within a 50 mile radius of a properly working nuclear plant0.02 mr/year *Reference: Nuclear Power Quick Reference II, IEEE.

12. HEALTH EFFECTS OF RADIATION amount of exposure duration type of radiation health age part of body exposed All of these help to determine the effect of the exposure.

13. Low-level radiation Less than 5 rems of exposure/year even at this-increases likelihood of developing cancer effects of continued low-level exposure is cumulative How many rems are safe?

14. High-level radiation Exposures over 5-10 rems/year 650 rems kills all people within a few hours to a few days 300 rems is the LD50 for people within 60 days 50-250 rems sublethal dose (does not result in immediate death) suffer from radiation sickness first nausea and vomiting, then 2-14 days later diarrhea, hair loss, sore throat, reduction in blood platelets, hemorrhaging and bone marrow damage occur. Sublethal doses can have delayed effects such as cancer, leukemia, cataracts, sterility, increase miscarriages, stillbirths, and early infant deaths.

15. Questions to think about. 1. What level of risk do we consider acceptable? 2. At what point do the benefits of x-rays, nuclear power and other uses outweigh the risks?