radiations Flashcards
atom
smallest building block of matter
mass number
total number of protons and neutrons
atomic number
number of protons
Isotope
an atom with the same numbe rof protons and electrons but a different number of neutrons
ionisation
the removal or addition of electron from an atom
activity (Bq)
the number of decays in one second
half life
time for the activity of a source to half
absorbed does, D, grays, (Gy)
The energy absorbed per kilogram of tissue
Equivalent Dose, D (Sv)
The biological harm caused by radiations
Fission
a large nucleus splits to produce two smaller nuclei
chain reaction
the neutrons released by a fission reaction produce further fission reactions. The process repeats
Fusion
Two Smaller nuclei join together to produce one larger nucleus
A=N/t
activity
D=E/m
absorbed dose
H=DwR
Equivalent Dose
H(dot)=H/t
Equivalent dose rate
the nucleus of the atom contains
positive protons and uncharged neutrons
electrons
orbit the nucleus at high speed
an atom is neutral
because there is the same of protons and electrons
alpha
particle, helium nucleus, absorbed by paper, most ionising
beta
particle, fast moving electron, 3mm of aluminium, second most ioning
gamma
wave, travels at speed of light, 3cm of lead and 1m of concrete and is the least ionising
background radiation comes from
natural and man-made sources
the average annual dose of a background radiation
2.2mSv
the average effective does rate for a member of the public is
1mSv
the average annual effective dose rate for a radiation worker is
20mSv
what can detect radiation
a GM tube, photographic film
when radiation hits photographic film what will happen
it turns black and fogs
what factors affect the biological harm of ionisng radition
absorbed dose
type of radiation
body organs or tissue exposed
radiation weighing factor
the higher the rating the more damage the radiation caused
radiation weighing factor is given
on the relationship sheet
to reduce equivalent dose
- use shielding
-reduce distance from source - reduce exposure time
the fuel rods
contain the uranium fuel
the moderator
slows down neutrons
the coolant
transfers energy from reactor to the heat exchanger
the containment vessels
absorbs neutrons and ionising radiation
disadvantages of nuclear power
-waste products are extremely dangerous
advantages of nuclear power
more energy is produced than coal/gas/ no greenhouse gases are produced
