INDUSTRY - Production

Production:
An outline of how Americium-241 is created. 

The element Americium, atomic number 95 (Am), a transuranic element, was discovered in 1945 during the Manhattan Project in USA. Americium’s first sample was first produced by the bombardment of neutrons into plutonium by the process using a nuclear reactor at the University of Chicago. Americium-241 was the first isotope to be produced with a half-life of 432 years. A fuel from a power reactor contains 1% plutonium (Pu), formed in a nuclear reactor by neutron capture form Uranium-238. Of this 1%, 10%-15% is the radioisotope Pu-241, with a half-life of 14yrs.Pu-241 then decays to form Am-241 through emission of beta particles. Shown in the equation below:

²⁴¹₉₄Pu --> ⁰_-1e^- + ²⁴¹₉₅Am 

INDUSTRY - Radiation

Radiation:
As isotopes decay they emit radiation. 

Amercium-241 (Am-241) decays by the emission of alpha particles (4/2He) and gamma radiation to become Neptunium-237, shown in the nuclear decay equation below:

²⁴¹₉₅ Am --> ⁴₂He + ²³⁷₉₃ Np

Neptunium-237 then decays through alpha emissions. This chain of decay with cease when nuclear stability has been achieved, becoming Bismuth-209.

Am-241 is detected by a Geiger-Muller tube counter. It contains gas which ionises and produces a small current of electricity, which is then measured by the number of pulses. Alpha radiation can be shielded by a thin sheet of paper and gamma rays are stopped by 5cm of lead. 

INDUSTRY - Uses & Properties

Properties & Uses:

Properties of Americium-241 impact the way in which it is used, smoke detectors being the main industrial use. 

Below lists the relationship between Am-241 Properties and Uses:

Properties	Uses
Atomic mass of 241.056823	This means various forms of this element can occur, known as isotopes. Different isotopes have slightly different properties to fulfil different uses.
Appearance: Silver/metal colour, crystalline, Its boiling point is 2607°C and melting point is 994°C	As Am-241 boiling point and melting point are extremely high, the natural state will be a solid. The isotopes chemical form is Americium Oxide (AmO2)
All isotopes of Am-241 are radioactive and decay by alpha emission and also gamma rays.	The use of this isotope is widely used in domestic and industrial smoke detectors. Other uses include: Medical Diagnosis Fluid-density gauging Aircraft fuel gauge (Device used to indicate the fuel level in the tank)   Thickness gauge in glass industry
A mixture of Am-241 and Beryllium are capable of emitting neutrons	These neutrons can be used for research.

Future Uses: European Space Agency are considering Am-241 to be used in their space probes

Smoke Detectors: 
Americium-241 main use is in industrial and domestic smoke detectors. So how do they work?

Americium-241 has a relatively long half-life of 432 years making domestic smoke detectors a reliable radioisotope that will last generations without the need to replace it. The alpha particles emitted by the Am-241 isotope collide in the ionization chamber with oxygen and nitrogen from the air, to create ions. Two metal plates are positioned within the ionisation chamber, one positively charged, the other negative. 

How Am-241 works in a smoke detector

The charged ions attract themselves to these metal plates creating a small electric current as they move towards the positive or negative charged plate. As smoke enters the ionisation chamber, it disrupts the current as smoke particles attach to the charged ions and neutralizing them. As these particles are now at a neutral electrical state, they will no longer be attracted to the charged metal plates, therefore reducing the current. Once the current has dropped significantly, the alarm is triggered.

INDUSTRY - Safety

Safety:
Safety including benefits and problems from Americium-241

Benefits and Problems:

Benefits	Problems
Am-241 lasts for generations. This means smoke detectors will not need to be replaced often.	Am-241 is insoluble but when taken in soluble form it is potentially dangerous. As it decays both alpha activity and gamma emissions, it tends to accumulate in the liver and bones having a massive health risk of bone problems and cancer.
Am-241 doesn’t need to be in huge quantities to be affective. In smoke detectors, less than 1g is used meaning it won’t be harmful to a household, as the radiation dose is essentially zero.	The cost of producing Am-241 is $1500 per gram.
The amount of Am-241 used in smoke detectors is 0.29 micrograms. This mean a gram of the isotope provides enough active material for more than 3 million household detectors.	Environmentally, Am-241 escapes from industries as an oxide (insoluble). However through biological processes, increase in solubility may occur. This will result in water contamination and sickening those who consume it.
The Am-241 effectively ionises particles in the air, which works the smoke alarms. Smoke alarms save people’s lives, bringing about the awareness of possible fire within the house.

Further Safety:

Precautions:
In smoke detectors Am-241 is covered and securely bound in a metal foil to reduce radiation when being used in smoke detectors.Inhaling Am-241 can lead to soluble parts of the isotope to concentrate on lungs and stomach. 
Protective gear such as gloves, foot ware and respiratory equipment must be worn for workers coming into contact with the radioisotope. Precautions must still be taken and it is advised:

- To not burn smoke alarms in order for disposal
- Do not attempt to dismantle a smoke alarm. 

Storage:
When storing Am-241, strict guidelines are to be followed. Sourced from the U.S.NRC a licensed worker…  “Shall not possess at any one time, at any location of storage or use, more than 0.185 megabequrel of Am-241”. This form of calibration also has a strict transfer and transport rule that has to have specific labelling and a signature of authority. The radioactive material is stored in a closed container specifically designed and constructed to contain Am-241, which bears the authorised label. 

Disposal:
Concern about disposal of smoke alarms has reduced. This is because the amount of Am-241 within the smoke detector as very small. From an environmental and public health view, this amount of Am-241 is not a hazard. As the radioactive material is also securely wrapped in metal foil, it is said to be safe to dispose of smoke detectors in household bins. The Radiation Health Committee believes smoke detectors are safe to be added to landfill and that returning them to the manufacturer is not warranted. 

INDUSTRY - Discussion

Discussion:
Through a series of sources with a reputable name, information was sourced and used to construct a website. The information on this website is considered to be reliable through reading repeated information from various sites. Both (U.S.EPA, 2012) and (World Nuclear Association, 2015) gave the diagram and correct information of how a smoke detector works, this an example of the consistency shown in the sources used as information overlapped and matched. These websites make themselves valid through an author or organisations name and a date of publish. This information has been made valid and reliable as a secondary source. 

Reference List:


(The Health Physics and Radiological Health Handbook Revised Edition, 2002) Strontium, Accessed: 16/05/15 (http://www.researchcompliance.uc.edu/Libraries/Isotopes/Am-241.sflb.ashx) 

(U.S.EPA, 2012) Accessed: 16/05/15 (http://www.epa.gov/radiation/sources/smoke_ion.html)

(World Nuclear Association, 2015) Accessed: 16/05/15 (http://www.world-nuclear.org/info/non-power-nuclear-applications/radioisotopes/smoke-detectors-and-americium/)

(ARPANSA, Standards Development & Committee Support Section, 2001) Accessed: 16/05/15 (http://www.arpansa.gov.au/pubs/rhc/sd_rhc_01.pdf ) 

(ANSTO, nd) Accessed: 18/05/15 (http://www.ansto.gov.au/NuclearFacts/BenefitsofNuclearScience/Inthehome/)