12
LOCKHART AND PATTERSON
Tassie 6
Experimental Evaluation of 0.20 #Ci Radon Released into a Chamber of
0.31 m? Volume and Sampled at the Rate of 0.00196 m3/min*
Sample
Elapsed
Countt
Countt
.
Ratio
(min)
“
oe
feu
Time
Count
Correction
Factors
tera
FI
Corrected
Count
Filter
ows Efficiency
faa
Calculated
Radon Cone.
(pCism’)
Expected
Count f111
From
100 pCifm?
Radon
p
Corrected
for p
Equilibrium
Assumed§
I
0-20
2390
1660
0.695
510
1.00
1.22 * 198
225
5.42 * 105
0.30 & 105
0.052
2
30-50
{0400
5360
[0.5155
510
1.00 .
5.30 x 108
1370
3.87 * 105
1.28 x 108
10.27
3
60-80
16100
7000
10.435
510
1.00
8.21 x [6
2500
3,28 x (08
1.99 « 105
(0.46
4
90-110
16900
7LO0Q
40.420)
510
1.00
8.62 x 106
2810
3.07 « 105
9.09 x 105
70.5]
5
120-140
20200
8120
10.402]
510
1.00
10.31 x 106
3230
3.19 x 105
2.50 x 105
10.58
6
150-170
19920
7920
70.398]
510
1.00
10.16 x 106
3320
3.06 x 105
2.46 x 10°
0.60
7
8
180-200
260-280
20380
21480
7980
8220
[0.392
70.383
5106
510
1.00
1.00
10.39 x 106
10.95 x LOS
3480
3730
2.99 x 105
2.94 x 105
2.52 x 105
2.65 « 105
10.62
0.67
9
284-305
16940
6600
10.390];
510
2.00
8.64 x 106
3530
2.45 * 105
2.09 « LO
0.63
*An 0.34 (dia.) DOP aerosol was added 10 min before the start of the experiment to a concentration of 104 particies/cc; the radon addition was
made during the initial 3 min of the experiment.
tCorrected for counter background; a negligible background of airborne radioactivity was present. All results were normalized to the D counter as
calibrated August 2, (965.
Reciprocal of 0.00196 m/min.
§Expected counts were obtained from Fig. 7; for the equilibrium condition this value was 4130 counts.
os
08
EQUILIBRIUM VALUE
Oo? Z
cprun’B=
*
‘a
=X PERIMENTAL
*
@.06}°
0.5
o
O7
3 06
2
qor 05
=
=
© O4;-
o 04
3 031,
mo
eS
u
a
a
ao
g203
Ere,
a
© o2b
x O02
Oi
0
0
EQUILIBRIUM VALUE
oO.
L
L
2
{
3
}
4
AGE OF RADON MIXTURE (HOURS)
5
6
Fig. |1 ~ Temporal changes in the RaC/RaB atom ratio (p}
following release of 0.20 wCi of radon inio a chamber (room)
of 35 m? volume. The samples were taken at 0.212 m3/min for
20 min. The background of old radon was approximately
500 pCi/m?,
0
0
!
2
3
4
4
_t
AGE OF RADON MIXTURE (HOURS)
3
Fig. 12 ~— Temporal changes in the RaC/RaB atom ratio (p)
following release of 0.20 wCi of radon into a chamber of 0.31
m? volume. The samples were taken at 0.00196 m3/min for
20 min. The background ofother airborne radioactivity was
negligible.