Radiochemistry
Concepts and Applications
in Environmental
Chemistry
Isotopes
Too heavy, too light, rarely just
right.
Table of Isotopes
1998 Version, 3000+ isotopes
Properties of , ,  and 
Properties of , ,  and 
ALPHA
Symbol
, 42He 2+
Charge
+2
Mass (kg) 6.642x10-27
Velocity
0.05c
(c=2.998x108m/s)
Relative
Ionization
1x104
Potential
Relative
Penetrating
1
Potential
BETA
X-, & GAMMA
, 0-1, 0-1e
 and 
-1
0
9.116x10-31
0
up to 0.995c
c
1x102
1
1x102
1x104
Penetration Potential
Ionization of Gas
Ionization of Liquids
 Scintillation Detection
Solid-State Semiconductor
Detectors
HPGe Detector Structure
CANBERRA Analytical Nuclear Instruments
Ionization of Solids
 Spectroscopy with HPGe
“Ultra-Low” Background
Considerations
Cosmogenic - from the cosmos
Auroras
Naturally Occurring Radioactive
Materials (“NORM”)
Cosmogenic:
3
H
7,10
Be
35,38
S
14
C
18
F
36,38,39
Cl
22,24
Na 26Al
37,39
Ar 53Mn
31,32
59
Si
Ni
80
32,33
P
Kr
Primordial:
40
K 50V 87Rb 113Cd 115In
148
Sm 152Gd 174Hf 176Lu
232
Th+daughters
235
123
Te
187
Re
138
La 144Nd 147Sm
190,192
Pt 209Bi
U+daughters
237Np+daughters
238
U+daughters
Localized “Hot Spots”
Location
Annual Dose(mSv/y)
United Arab Emirates
Radon Springs, France
Kerala Region of India
Guangdong Province, China
Morro De Faro, Brazil
Guarapari, Brazil
Ramasari, Iran
USNRC Occupational Dose Limit
USNRC Limit for Members of Public
14
16
30
33
70 - 140
175
480
50
20
Oklo Quarry, Gabon
Fossil Fission Reactor
Oklo Quarry, Gabon
In 1972 ore deposits were found to contain
significantly different isotopic compositions of certain
elements than from the mean found in nature.
142Nd
normally 27% in nature, at Oklo it was <6%.
99Ru normally ~28% in nature, at Oklo it was 13%.
235U normally 0.72%, at Oklo it was 0.48%.
From 87Rb/87Sr dating, Oklo deposits are 1.7E9 years
old, at that time U enrichment was ~3% 235U!
Fossil Fission Reactor
Operated on and off at
~100kW output for 1E6
years.
Once the natural
reactors burned
themselves out, the
highly radioactive
waste they generated
was held in place deep
under Oklo by the
granite, sandstone,
and clays surrounding
the reactors’ areas
Significance today
with Yucca Mountain
proposed national
repository.
Radioactive Material is
Everywhere
 Cosmic Radiation
 Indoor Air &





Structural Materials
Rock & Soil Radiation
Water & Aquatic Food
Ingestion
Food, milk digestion
Crop digestion
Inhalation Skin
Absorption
“Reference Man” with a 70Kg.
Body Mass
Nuclide
Daily Intake of
Nuclides
Uranium
Total Mass of
Nuclide Found
in the Body
90 g
Thorium
30 g
3 g
Radium
31 g
2.3 g
Carbon-14
95 g
2 g
Potassium-40
17 mg
0.39 mg
Tritium
0.06 g
3 g
Polonium
0.02 g
0.6 - 5 g*
Assumes a smoker.
*
1.9 g
Sources of Radiation Exposure -Update
Release of NRCP No. 160 (03/03/09)
Exposure
Category
Effective Dose per Individual in the US Population
(mSv)
(1)
2006
(2)
Early 1980s
Ratio (1)/(2)
Ubiquitous
Background
3.11
3.00
1.04
Medical
3.00
0.53
5.67
Consumer
0.13
0.13
---
Industrial,
educational,
research
0.003
0.001
---
Occupational
0.005
0.009
---
Total
6.25
3.67
1.70
Energy Liberated can be Absorbed
Absorption in body tissue may result in physiological
injury
Absorption is the principle by which detection is based.
The degree of absorption or type of interaction is a
primary factor in determining shielding requirements.
Health Effects of Ionizing
Radiation
Direct Effect on Cells:
damage to DNA from
ionization.
If the cell is exposed to
radiation, the probability of
the radiation interacting
with the DNA is very small
since these critical
components take up less
than 0.5% of the cell
volume.
USDOE: Human Genome Project
Health Effects of Ionizing
Radiation
Radiolysis of water produces the
following types of sequences:
H2O +  ray  HOH+ + e- H2O + e-  HOHHOH+  H+ + OH*
HOH-  H* + -OH
OH* + OH*  H2O2 (hydrogen peroxide)
Net Effect: Free radical formation
Indirect Effect on
Cells:
decomposition of water.
If the cell is exposed
to radiation, the
probability of
interaction with
cellular water is
greater since water is
99.5% of the cell
volume.
Risk Models
ALARA
The basic tenants of ALARA are the use of time,
distance, and shielding to minimize radiation
exposures.
Radon Target Organ - Lungs
Radon (Rn) and
Daughter Products
(RDPs) inhaled or
ingested.
Most of the Rn from
respiration is exhaled.
Ingested Rn out-gasses
through the lungs.
RDPs remain stuck to
lung tissue. Po218 & Po214
emit alpha particles within
the 1st hour.
Alpha Particle in the Lung
Alpha particles strike lung
cells causing possible
physical and/or chemical
damage.
3 fates for cell
• Damaged & Repaired
• Damaged, not
Repaired
• Killed
48 hour time lapsed microscopic
photograph of alpha tracks emitted from a
radioactive particle of Pu-238 lodged in the
lung tissue of an ape.
www.ccnr.org/alpha_in_lung.html
Iowa Radon Lung Cancer Study
Found excess risk of 50% for exposures that are
equivalent to 15-years spent at an average
radon exposure of 4 pCi/L. Overall, the risk
estimates obtained in the study suggest that
cumulative Radon exposure in the residential
environment is significantly associated with lung
cancer risk.
Field, R.W., Lynch, C.F., Brus, C.P., Woolson, R.F., Fisher, E.F., Platz, C.E., Robinson,
R.A., Steck, D.J., Neuberger, J.S. Residential Radon Gas Exposure and Lung
Cancer: The Iowa Radon Lung Cancer Study, American Journal of Epidemiology,
151(11);1091-1102, 2000.
Radon Geology
Source
Rn is constantly being
generated by the
uranium in rocks, soil,
water, and construction
materials derived from
rocks and soil.
Uranium is found in
small concentrations
throughout the earth’s
crust. On average, 1
acre down to a 5 ft.
depth would contain 50
lbs. of Uranium.
www.atral.com/U238.html
Radon Potential  Uranium Potential
Actual Radon Zones
Radon Migration
Typical Indoor Air
Rn range - 1 to
1000 pCi/L.
Typical Soil Air
Rn range - 200 to
100,000 pCi/L.
Dissolved Rn in
Groundwater
range - 100 to
3,000,000 pCi/L.
High Variability in Radon
Concentration
Nuclear Generating Plants
Every form of energy generation has
advantages and disadvantages.
Coal
Nuclear
Advantages
Fuel is inexpensive
Easy to recover (in U.S. and China)
Advantages
Fuel is inexpensive
Energy generation is the most
concentrated source
Waste is more compact than any
source
Extensive scientific basis for the cycle
Easy to transport as new fuel
No greenhouse or acid rain effects
Disadvantages
Requires larger capital cost because of
emergency, containment, radioactive
waste and storage systems
Requires resolution of the long-term
high level waste storage issue in most
countries
Potential nuclear proliferation issue
Disadvantages
Requires expensive air pollution
controls (e.g. mercury, sulfur dioxide)
Significant contributor to acid rain and
global warming
Requires extensive transportation
system
“Clean Coal” does not yet exist
New NGP designs - ABWR
New NGP designs - PBMR
Westchester County
Dept. of Labs &
Research is a
FRMAC partner
Laboratory and
Personnel Assets are
registered in the
event of an
emergency