Nuclear ChemistryChemical and Biological Warfare

The Basics of RadiationRadioactive materials have an

unstable nucleus that release one or more particles or energy

Nuclear radiation refers to the released energy and matter.

A large part of the radiation you are exposed to comes from background radiation (from the sun – solar and the earth – terrestrial.

Radiation is going through you all the time.

A review of Isotopes

• Isotopes have a different number of neutrons than the more common (stable) version of the element.

• Isotopes are unstable and release radioactive particles.

• The type of particle released and the timing for its release is dependent on the element.

Types of Nuclear Radiation – the basics

• 1. Alpha Particles () – release of a positively charged particle with a large mass. Do not travel far because of the size and can barely pass through a piece of paper.

• 2. Beta Particles () – Negatively charged particle with very little mass. Travels faster and has more energy than alpha particles. Can travel through 3 mm of aluminum or 10 mm of wood.

Types of nuclear Radiation - continued

• 3. Gamma Rays () – Are not made of matter and do not have an electric charge. They consist of electromagnetic energy called PHOTONS. Gamma Rays have very high energy and can travel through 60 cm of aluminum and 7 cm of lead.

• 4. Neutron Emission – The release of a neutron from a nucleus. There is no charge which allows them to travel much farther. (can travel through a 15 cm block of lead). The process occurs during nuclear fission.

Alpha Particles:

Radium

R226

Radon

Rn222

+

88 protons138 neutrons

86 protons136 neutrons

2 protons2 neutrons

The alpha-particle is a Helium nucleus.

It’s the same as the element Helium, with the electrons stripped off !

Beta Particles:

CarbonC14

6 protons8 neutrons

NitrogenN14

7 protons7 neutrons

+ e-

electron(beta-particle)

During this decay, one neutron changes to a proton And an electron is released.This causes Carbon 14 to decay to Nitrogen 14.

Gammy Rays

NeonNe20

10 protons10 neutrons

(in excited state)

10 protons10 neutrons

(lowest energy state)

+

gamma

NeonNe20

A gamma is a high energy light particle.

It is NOT visible by your naked eye because it is not in the visible part of the EM spectrum.

Gamma Rays can cause much more damage to living things Than alpha and beta particles.

A gamma is a high energy light particle.

It is NOT visible by your naked eye because it is not in the visible part of the EM spectrum.

Gamma Rays can cause much more damage to living things Than alpha and beta particles.

Types of Radiation

Importance to Us: Half-Life

• Half-Life. This term refers to the amount of time it takes for half of the radioactive substance to decay. Each radioactive isotope has a different decay rate. Measuring half-life can be useful when dating materials.

• For example: Potassium-40 decays to Argon-40, so the ratio of Potassium-40 to argon-40 is smaller for older rocks than it is for younger rocks.

• Scientists use Carbon-14 to date more recent materials like remains of an animal or parts of ancient clothing.

Importance to Us: Producing Energy

Fission and Fusion

Fission

• Fission is the process of splitting heavier nuclei into lighter nuclei

• Fission releases Energy • The mass equivalent of 1kg

of matter is more than the chemical energy of 22 million tons of TNT

• Neutrons released by fission can start a chain reaction…a continuous series of nuclear fission reactions.

Fission Uses:

• 435 Nuclear Power plants worldwide• 1/6 of the worlds power is nuclear

Nuclear Power in the U.S.

Nuclear Power in the Northeast

Problems with Fusion: Nuclear Waste

Nuclear Waste

• Nuclear Waste has been accumulating since the mid-1940’s and is currently in temporary storage at 131 sites in 39 states

• Nuclear waste remains highly radioactive for thousands of years.

• It will still be potentially harmful to humans long after the manmade containers holding the waste have disintegrated.

Most Used Current Nuclear Waste Sites

Future Plans for Nuclear Waste: Yucca Mountain

• Will become the nation's first long-term geologic repository for spent nuclear fuel and high-level radioactive waste that is currently stored at 126 sites around the nation.

• Yucca Mountain is located in a remote desert on federally protected land within the secure boundaries of the Nevada Test Site in Nye County, Nevada. It is approximately 100 miles northwest of Las Vegas, Nevada.

Fusion: A possible energy source for the future

• Fusion is the production of a thermonuclear reaction in a gas discharge• Called fusion because it is based on fusing light nuclei such as hydrogen

isotopes to release energy, similar to that which powers the sun and other stars.

• A vast, new source of energy• Fuels are plentiful (an isotope of hydrogen in ocean water)• Inherently safe since any malfunction results in a rapid shutdown• No atmospheric pollution leading to acid rain or the greenhouse effect• Sunlight is energy released from fusion reactions in the sun.• The price of fusion is estimated to be equivalent to that of fossil fuels• Fusion can give us energy for millions of years

Fission vs. Fusion

• European Safety and Environmental assessment of Fusion Power (SEAFP) team in 1992 established Fusion as a “very clean and environmentally friendly source of energy for the future with very good inherent safety qualities, there are no chain reactions and no production of ‘actinides’”

• The only waste products are helium, and toxic waste that is contained within the chamber and is not long term

• Fusion produces no climate-changing or atmosphere-polluting emissions• With Fission, relatively low environmental issues when costs are paid to maintain

an environmentally friendly work area, however these costs are so high that it would be a problem in second and third world countries. There is also the problem of a malfunction, worst case scenario can be very severe as opposed to the shut down process of fusion.

• At this time, Fusion reactors cannot be productively made.

Importance to Us: Nuclear Medicine

Nuclear Medicine

• The process of using radioactive isotopes for detecting disease – generally using gamma rays (called radioactive tracers)

• Also includes the use of radioactive isotopes (usually beta decay) as treatment for disease (like cancer)

Importance to Us: Radiation Exposure

• You are exposed to radiation everyday• Background Radiation – nuclear radiation that arises

naturally from cosmic rays and from radioactive isotopes in the soil and air

• We are adapted to survive low levels of this natural source of radiation

• Radiation is measured in rems or millirems

Radiation Exposure

• There are many occupations where people are exposed to higher levels of radiation.– Nuclear radiation, health physics, radiology, radiochemistry, X-ray

technology, MRI– It has been decided that these occupations can be exposed to 5000

millirems annually plus regular background radiation.

• Exposure amounts will also depend on where a person lives.• Exposure may increase based on some day-to-day activities

as well

Examples of Everyday Radiation Exposure

• Average annual radiation dose is 360 millirems per person. 300 from natural sources. • Sleeping next to someone for 8 hours: 2 mrems • Exposure comes from the naturally radioactive potassium in the other person's body• Coal plant, living within 50 miles: .03 mrem There is much thorium and uranium in coal. • Living within 50 miles of a nuclear power plant adds .009 mrem of exposure. Both figures

are considered extremely low levels.• Living in a masonry home: 7 mrems Stone, brick and adobe have natural radioisotopes in

them.• Living on the Earth: 200 mrems We are living in a sea of radon. It is made from the natural

decay of uranium and thorium in the soil, left over from the creation of the solar system. Radon is a rare gas that diffuses out of soil and into the air. It contributes more than half of our background

Examples of Everyday Radiation Exposure

• Smoking: up to 16,000 mrems The tobacco leaf acts like the absorbing surface of charcoal in a radon test kit. It collects long-lived isotopes of airborne radon, like lead-210 and polonium. Small portions of the lungs can get relatively whopping doses, compared to background levels.

• Porcelain teeth or crowns: tenths of a rem Uranium is often added to these dental products to increase whiteness and florescence.

• Air Travel: 1 mrem per 1000 miles 30,000 feet above the ground you're closer to the ionizing radiation (high-energy gammas well as particles) from the sun.

• Grand Central Station, NYC: 120 mrem for employees Its granite walls have a high uranium content.

• Brazil Nuts: This is the world's most radioactive food due to high radium concentrations 1000-times that of average foods.The US Capitol Building in

• Washington DC: This building is so radioactive, due to the high uranium content in its granite walls, it could never be licensed as a nuclear power reactor site.

Issues from Increased Radiation Exposure

• 1500% increase in incidence of testicular and ovarian cancer in children on Navaho reservation in uranium mining area

• 500% increase in bone cancer in children affected by uranium

• 250% increase in leukemia (all ages) in the Navaho population

• 200% increase in each of the following non-cancer effects: miscarriage, infant death, congenital defects, genetic abnormalities, learning disorders.

Issues Continued

• 400% increase in leukemia incidence in the population living downwind of the Pilgrim nuclear power reactor in Massachusetts in the first 5 years after fuel was know to have leaked excess radioactivity.Baseline: Disease in population before and after Pilgrim radioactive releases and comparison to upwind population.

• 300—400% increase in lung cancer in the general population within the plume of the Three Mile Island accident releases

• 600—700% increase in leukemia in the general population within the plume of Three Mile Island accident releases Baseline: Disease in population upwind (out of the radiation plume path) is compared to disease in population downwind (in the pollution plume.)

• 50% increase in childhood cancer incidence in the Three Mile Island area for each 10 millirem increase in radiation exposure per year.

Issues Continued

• 500% increase in leukemia among Utah nuclear bomb test Downwinders • 121% increase in thyroid cancer incidence in the same group • 200% increase in breast cancer • 700% increase in bone cancer • a greater then 120% increase in thyroid cancer in those who drank milk

laced with Iodine-131 from atmospheric nuclear weapons tests

• 200% increase in lung cancer in women who received radiation treatments for breast cancer

• 66—96% increase in early cancer deaths due to background radiation

Chemical Warfare

• The use of chemicals as a weapon.• This type of warfare is unique in that it does not just

depend on the initial blast (and radius) for destruction, but relies on the chemical to infiltrate an area and cause increased number of casualties.

History and Use of Chemical Weapons

Chemical warfare technology timeline

Agents Dissemination Protection Detection

1900s ChlorineChloropicrinPhosgene

Mustard gas

Wind dispersal   Smell

1910s Lewisite Chemical shells Gas maskRosin oil clothing

 

1920s   Projectiles w/ central bursters CC-2 clothing  

1930s G-series nerve agents Aircraft bombs   Blister agent detectorsColor change paper

1940s   Missile warheadsSpray tanks

Protective ointment (mustard)Collective protection

Gas mask w/ Whetlerite

 

1950s

1960s V-series nerve agents Aerodynamic Gas mask w/ water supply Nerve gas alarm

1970s

1980s   Binary munitions Improved gas masks(protection, fit, comfort)

Laser detection

1990s Novichok nerve agents      

Biological Warfare

• Introduces toxins such as viruses into an area with the intention of killing or seriously injuring an area.

• Examples include: poisoning water systems, spraying chemicals in the air