Whole report - STUK

STUK-YTO-TR 175
±1.1% to ±18.7%, when all measurements are
taken into consideration.
6.4 Comparison of MMCA and
DART, CsRatio and SAMPO
During the measurements of the September campaign
one measurement spectrum was taken with
both the DART and the MMCA analyser for each
assembly at one azimuthal position. The spectrum
from the MMCA was evaluated with the CsRatio
and the spectrum from the DART was evaluated
with the SAMPO. The results are shown in Figure
26. There is a systematic difference in the peak
areas, which is not much of concern since the me-
Table XII. 244 Cm neutrons vs. gross gamma without
averaging over four sides of an assembly. UL
and LL as in Table IX.
a² s b²
a²
s
b²
R 2
Experimental
– 8.39
0.18
3.95
0.07
0.970
UL
– 8.20
3.94
LL
– 8.58
3.96
asurements are relative, not absolute. The standard
deviation of all ratios is ±2.5%. The errors of
the peak areas given by both programs range between
1 and 2%. Thus, it can be concluded that
both MCAs and both analyser programmes provide
similar results, but seem to underestimate the
errors somewhat.
2000
244
Cm neutron counts (cps)
1000
800
600
400
200
100
80
60
40
20
10
8
200 300 400 500 600 700 800 900
Gross gamma (arbitrary units)
Figure 25. 244 Cm neutrons vs. gross gamma signal without averaging over four sides of an assembly.
Dotted lines describe the error corridor.
Peak Areas Calculated by CsRatio/SAMPO
1.1
1.05
Cs-137 Area Ratio (CsRAtio/SAMPO)
1
0.95
0.9
0.85
0.8
a12358_5
a10181_4
a12387_4
a_12500_4
a7472_4
a7516_4
a7055_d
a12366_4
a10475_4
a12323_4
Figure 26. Ratio of the peak areas calculated by CsRatio and SAMPO.
a6124_d
Measurement File ID (=Assembly)
a10003_4
a9367_4
a12338_4
a6124_d
AVERAGE
26