Nuclear Radiation Today: lec 9.3

Lecture 9.3 Sprint nuclear missile

Where is radiation?

•Background radiation is everywhere

•Our bodies have adapted to it

•Smoking increases radiation exposure

Radiation exposure

• Altitude increases exposure

• Flying in planes increases exposure

• Radon, medical X rays , diagnostic tests also increase exposure

(To find your radon exposure, visit www.dhs.ca.gov/radon/default.htm

click “radon exposure by ZIP code”)

Beneficial Uses

•Smoke detectors use Americium

•When smoke interrupts the sensor, an alarm rings

Nuclear Medicine

•1 out of 3 people admitted to a hospital undergo some form of nuclear medical procedure•Treatments, diagnosis

CAT scan:ComputerAxialTomography

A real cat scan?

MRI- magnetic resonance imaging

•Images of internal organs can be viewed•Diagnosis of Alzheimer’s , cancers can be made

MRI images

liverbrain

Radiation therapy : cancer treatment

• Rotating machine delivers precise doses from varied angles to kill cancerous tumors

Diagnosis and treatments using radiation

•Radioactive “seeds” treat prostate cancer

•Radioactive tracers allow MRI, PET scans to image soft tissue, showing disease and helping diagnosis

MRI

PET scan

Nuclear Risks

•Because radiation ionizes atoms, it can cause cancer in living things

•Dosimeters record a wearer’s exposure over time

Chernobyl reactor

Nuclear Power

Benefits:• Reactors generate electricity without

air Pollution or greenhouse gases.• There is more energy in Uranium

than in coal or gas.

Problems: reactors create radioactive waste with very long half-lives ( U 238

is 4.5X 109 years)

Nuclear waste storage: where will it go?

14 tons of Uranium

Fusion research

•1 lb of Hydrogen could yield the energy of 16,000,000 lbs of coal

•Water would be the source for H•Problem: releases neutron radiation•Still in research stage