Facts to know Flashcards
1
Q
Vitrification
A
the rapid cooling of liquid medium in the absence of ice crystal formation
2
Q
Pu-Be
A
a neutron producing source (will need hydrogenous material to shield)
3
Q
General area dose rates are checked between which body parts?
A
rates are checked between head and knees
4
Q
EPA Protective Action Guidance for members of the public during early phase of nuclear accident includes:
A
A total effective dose equivalent exceeding 1 rem and a CDE to thyroid exceeding 5 rem
5
Q
HVL and TVL equations
A
HVL= ln(2)/u
TVL=ln(10)/u
I=I(0)e^(-ux)
6
Q
H-3
A
Pure beta emitter Half life: 12.3 yrs Biological:10-12 days Energies: Max (18.6 keV) Avg (5.7 keV) Requires urine bioassay
7
Q
C-14
A
Pure beta emitter
Half life: 5730 yrs
Biological: 12 days
Energies: Max(156) Avg: 49 keV
8
Q
F-18
A
Gamma (511 keV) and Beta emission (634 keV) Half-life: 1.83 hrs Biological (6 hrs) Positron annihilation
9
Q
P-32
A
Half life: 14.3 days
Biological: 257 day whole body
Bone: 1155 days
Energies: Max (1710 keV) Avg (695)
10
Q
S-35
A
Pure beta emitter Half life: 87.5 days Biological (623 days) Energies: Max (167.5 keV) Avg 49 keV Critical organ (testis)
11
Q
Co-60
A
Half-life: 5.27 yrs
Biological:
Energies: 2 Gamma (1173 keV and 1333 keV) Avg.( 1250 keV)
Beta Max (318 keV) Avg (96 keV)
12
Q
Sr-90
A
Beta emitter
Half life: 28.2 yrs
Energies (546 keV)
Y-90 energies 2484 keV and 523 keV
13
Q
Tc-99m
A
Half life: 6 hrs
Biological: 1 day
Energies: Gamma (141 keV)
X-ray (18 keV and 21 keV)
14
Q
I-125
A
Half- Life: 60.1 days
Biological: 120 days
Energies: Gamma 35.5 keV
X-ray: 27 keV
15
Q
I-131
A
Half life: 8 days
Biological: 120 days
Energies: Gamma 364 keV and 723 kev
Betas: 606 keV
16
Q
Cs-137
A
Half life: 30.2 yrs
Energies: 662 keV and 32
Beta 174 keV
17
Q
Ra-226
A
Half life: 1600 yrs
Energies: Gamma 186 and 609
Alpha 4785 keV
GM detector
18
Q
Am-241
A
Half-life: 432 yrs Energies: gamma 60, 14, 18 Alphas: 5486 5443 5388
19
Q
Inverse square law formula
A
I1/I2=D2^2/D1^2
20
Q
Secular equilibrium
A
Parent half life»>Daughter half life
21
Q
Gas amplification factors in ionization chamber
A
equal to 1
22
Q
Limit for external surface contamination on DOT package
A
22 dpm/cm^2
Or 2200 dpm/100cm^2
23
Q
Clearance time for particulate traveling through trachea, bronchi, bronchioles, and alveoli?
A
0.1 hr, 1hr, 4hr, 10 to 15000+ days
24
Q
semi infinite cloud of gamma emitting noble gases, gamma contribution to dose rate formula
A
D=0.25 EX
D= rem/sec
E= gamma (MeV)* yield
X= concentration (uCi/cc)
25
Calculate RBE
Dose of 250 kVp x-rays
__________________
Dose of other radiation
26
Current LD50/60 in humans
410 rem whole body with no medical intervention
27
exposure levels where Gastrointestinal, Cerebrovascular, temporary sterility and permanent sterility occur
1000 rem, 5000 rem, 250 rem, 500 rem
28
PF for full face negative pressure SCBA (self contained breathing apparatus)
50 PF
29
PF for full faced pressure demand (positive pressure) SCBA (self contained breathing apparatus)
10,000 PF
30
PF for full faced demand airline respirator
100 PF
31
PF for full faced continuous flow, airline respirator
50 PF
32
PF for half mask, negative pressure air purifying respirator
10 PF
33
PF for full faced negative pressure air purifying respirator
100 PF
34
eV equals how many joules?
1.6 E-19 Joules
35
During early phase of accident, what effective dose equivalent limit set for emergency responders
5 rem
36
Agency approves respiratory protection devices
NIOSH (National institute of occupational safety and health)
37
Quality factor for thermal neutrons
QF 2
38
Quality factor the alpha particle, multiple charged particles, fission fragments, heavy particles of unknown charge
QF 20
39
QF of neutron of unknown energy
QF 10
40
QF for gamma/xrays
1 QF
41
how many rem in 1 sv
100 rem to 1 Sv
| .01 Sv to 1 rem
42
1 rad equals how many ergs
```
100 ergs (energy/g)
100 rads= 1 gray= 1 J/Kg
```
43
Gamma exposure rule of thumb
For gamma energy 0.07Mev to 4 MeV; in R/hr
D=6CEN/d^2 for measurements in feet
D=0.5CEN/d^2 for measurements in meters
If there are two energies, add them together
44
1 roentgen = how many C/Kg
1 R= 2.58 x 10^-4 C/Kg
45
3 naturally occurring decay series
Thorium (Th-232) (4n)
Uranium (U-238) (4n+2)
Actinium (U-235) (4n+3)
46
What is the Transport Index (TI)
the dose equivalent rate at 1 meter from package surface
47
Working level as a unit of radon decay is = ?
1 liter of air with emission of 1.3 E5 MeV Alpha
48
Range of alpha particles in air
For E<< 4 MeV, 0.56 E (cm)
| For 4
49
Transient equilibrium
Parent half life > D half life
50
When will parent and daughter never reach equilibrium
Parent half life < daughter half life
51
Avg risk from cancer following acute dose of 0.1 Sv (10 rem) of Low LET radiation to all body organs is
8 E-3
52
Under energy spatial equilibrium, 1 R of gamma rad is equivalent to absorbed dose in air and tissue:
0.87 rad air and 0.98 tissue
53
Rule of thumb for beta particle travel range in air and matter
```
12 feet per MeV
and
Emax
____
2
```
54
Relationship between mass and activity
Curies/gm= 1.308E8/ (AT)
Where A= atomic # and T = half life (days)
55
Equation for resolving time
```
N= n/(1-nt)
N=true count rate
n=observed count rate
t= resolved time
ex: t=200 sec; n= 6x10^4 cpm; N=7.5x10^4 cpm
```
56
What are the neutron classes
Thermal (0.025 eV), Epithermal/slow (0.025-100 eV), Intermediate (100 eV-100 keV), Fast (100 keV -20 MeV) Relativistic (<20 MeV)
57
Photoelectric effect, Compton scattering, Pair production
photo electric effect is dominant <200keV
Compton scattering is dominant 200 keV-5 MeV
Pair production is dominant > 5 MeV
58
kerma
the amount of KE transferred to charged particles per unit mass of any material by interaction of indirectly ionizing radiation in that mass
59
Committed effective dose equivalent equation
CEDE= intake/sALI * 5 rem
60
The recoil E of the product atom formed in the alpha decay of most naturally occurring alpha emitters is approx. what percentage of alphas particles energy?
2%
61
Dose rate with gamma constant equation
D=Γ*A/d^2
62
Beta dose rate rule of thumb
β=300CN/d^2
| β=30CN/d^2
63
Occupational dose limits
total effective dose: 5 rem
sum of deep dose and committed dose equivalent to individual organ or tissue : 50 rem
Dose equivalent to lens of eye: 15 rem
Shallow dose equivalent to skin or extremities: 50 rem
64
Dose limit to minors working with rad
10% of adult occupational dose limits
65
Dose limits to members of the public
100 mrem/ yr
66
Caution Radioactive materials sign meaning
In areas or items where radioactive material is used/stored. Information on material should include: 1. type of rad material 2. estimated activity 3. assay date 4. Individual responsible for material
67
Caution- Radiation Area sign meaning
Area where radiation levels could cause portion of individuals body to receive an exposure of 5 mrem/hr from external radiation
or 100 mrem in 5 consecutive days
68
Caution- High Radiation Area sign meaning
Area where level of radiation could cause major portion of individuals body to receive exposure of 100 mrem/hr.
69
Grave Danger- Very High Radiation Area sign meaning
an area in which radiation levels could result in individual recieving an absorbed dose of 500 rads in 1 hour @ 1 meter from source or surface it penetrates.
70
Radioactive White I package criteria
at any point on accessible surface of package: 0.5 mR/hr
| No transport index indicated
71
Radioactive Yellow-II criteria
At any point on surface: 50 mR/hr
| At 3 feet/1 meter from external package (TI): 1 mR/hr
72
Radioactive Yellow-III criteria
any point on surface: 200 mR/hr
| 3ft (1 m) from package surface (TI): 10 mR/hr
73
Effective half life formula
Teff= Tr*Tb/(Tr+Tb)
74
Reference man stats
```
Breathing rate: 2E4 ml/min
Water consumption: 2.2 L/day
Weight:70 Kg
Height: 170 cm
Works 40 hrs a week
2000 hrs a year
Has 100 nCi of K-40
```
75
organ weighting factors
```
Gonads 0.25
Breast 0.15
Red bone marrow 0.12
Lung 0.12
Thyroid 0.03
Bone surfaces 0.03
Remainder 0.06
Whole body 1.00
```
75
organ weighting factors
```
Gonads 0.25
Breast 0.15
Red bone marrow 0.12
Lung 0.12
Thyroid 0.03
Bone surfaces 0.03
Remainder 0.06
Whole body 1.00
```
76
2 sigma (95% confidence) error analysis
Count rate +/- 1.96(C/T^2 + Cb/Tb^2)^1/2
76
2 sigma (95% confidence) error analysis
Count rate +/- 1.96(C/T^2 + Cb/Tb^2)^1/2
77
What part of the body is of concern for an alpha, beta, and gamma radiation types
Alpha, ingestion (organs), beta is skin, and gamma is whole body
78
Radioactive atoms that have large neutron to proton ratio tend to decay by
beta minus decay
79
What is the energy of a photon that had an initial energy of 7 MeV and interacted twice by Compton scattering, first scattering at an angle of 10 degrees and then 180 degrees?
α=hv/mc^2 = 7 MeV/0.511 MeV= 13.7
hv'=hv* 1/(1+α(1-cos(o)) = 5.8
repeat with new value,
0.245 MeV
80
Isobar
nuclides that have the same atomic # (protons and neutrons)
81
Isotope
nuclides with same # of protons, different # of neutrons
82
Isotone
nuclides that have the same # of neutrons, different # of protons
83
Isomers
nuclides that have same atomic # and mass #, but different energy states
84
PF for respirator types
From greatest to least effective
Positive pressure recirculating, pressure demand = continuous flow, demand = negative pressure
Helmet/hood= full face, half face, loose-fitting
85
What does HEPA stand for
High efficiency particulate air (filter)
86
Alpha particle range
R= 0.56E
for E up to 4 MeV
1.24E-2.62 for 4-8 MeV
87
HVL of paraffin for 1 MeV neutron and 5 MeV
HVL for 1 MeV is about 3 cm
| HVL for 5 MeV is about 7 cm
88
How many C/Kg in 1 R
2.58*10^-4 C/Kg
89
Class I Laser
Considered to be incapable of producing damaging radiation levels during operation
Exempt from any control measures or other forms of surveillance
90
Class I M laser
Considered incapable of producing hazardous exposure conditions during normal operations, unless the beam is viewed with an optical instrument
Exempt from any control measures (besides use of optical instruments)
91
Class II laser
Emits in the visible portion of spectrum (0.4 to 0.7 μm)
Eye protection is normally afforded by the aversion response
92
Class II M laser
Emits in visible portion of spectrum (0.4 to 0.7 μm)
Eye protection is normally afforded by the aversion response for unaided viewing
Can be hazardous if viewed with certain optical aids
93
Class III Laser (Medium Power) (2 subclasses)
Both may be hazardous under direct & specular reflection viewing conditions
3R: Probability of injury is small if the eye is appropriately focused and stable
3B:Normally not diffuse reflection or fire hazard
94
Class IV Laser
Is hazardous to eye or skin from the direct beam
May pose a diffuse reflection or fire hazard
May produce laser generated air contaminants (LGAC) and hazardous plasma radiation
95
R to rad conversion factor
0.87 R/rad
96
Non-stochastic ALI equation
CDE=( I/nALI) * 50 rem
97
Dose equivalent rate equation
H= (H(rate)/λ)*(1-e^(-λt))
98
Rn- 222
Half-life: 3.8 days
99
Rad to MeV/gm
1 rad= 6.24 E7 MeV/gm
100
total error equation
```
E1= error 1
E2= error 3
En= Error n
```
(E1^2+E2^2+En^2)^1/2
101
Equation to find total disintegrations or mass from activity
N=A/λ ; will give you atoms/ disintegrations.
If want weight then: (convert to Bq, g/mole [ Rn-222 = 222 gm/mol], avagadros #)
A= Nλ
102
Solving for Biological half life
Tb= (1/ [(1/Teff)-(1/Tp)])
103
Solving for PF given DAC, concentration, stay time, max DAC hr
DAC-Hr= (concentration/DAC)*Stay time
_______________
PF
solve for PF
104
Formula for fraction of energy given off from electron beam
F= 7*10^-4 * Z*E
```
Z= atomic #
E= energy in MeV
```
105
4 pCi/L contributes to how much dose per year?
0.25 rem
106
How to find transmission factor
@ 1 meter
T=Xrate/Γ for 1 Ci
for anything other than 1, multiply by A
or
T=Be^(-ux)
Where B = buildup
107
Finding activity concentration in a room with flow rate
A=(A0/V)e^(-kt)
Where k = F/V + λ
F= flow rate
V= volume
108
Laser beam intensity reduction
Optical density= log (Io/I)
109
Peak power for laser
PP=Energy/time = watts
E in Joules
t= usually nsec
110
W value for alpha particles in air
W= 35 eV/ion pair
111
Restricted area parameters
An area where you could receive in excess of 2 mR/hr or 100 mR/yr
112
In the ionization region of a gas filled detector, the output pulse is approximately:
independent of the voltage over fairly large voltage range
113
what is relaxation length
ux
114
Sievert in SI units
1 Sv= 1 J/kg = 100 rem
115
Working level
One working level (WL) is defined as any combination of short-lived radon progeny (specifically, radon-222 progeny) in one liter of air that will emit 1.3 × 10⁵ MeV of alpha particle energy upon decaying completely.
116
Working level month is ? Hrs
170 hrs
4 weeks x 40 hr/week = 170
