38

Evaluation  of  the  results
The  evaluation  procedure  has  been  conducted  for
nuclides  with  four  or  more  results  (K-40,  Cs-134,
Cs-137,  Pb-210,  Ra-226,  Pu-239,240,  and  Am-241).


The  Z-score  for  an  item  indicates  how  far  and  in
what  direction  the  item  deviates  from  the  mean  of
its  distribution,  expressed  in  units  of  its  distribution’s
standard  deviation.  The  Z-score  value  for  an  item  is
calculated  according  to:
x t  -x
Z i=~
<J  ,
where
x  =  arithmetic  mean  of  the  values,
<J-  standard  deviation  of  the  values.

Z-score  of  K-40

Figure  A12.
Column  diagram  of
Z-scores  for  K-40.

3,00

2,00

1,00

0,00

-1,00

-2,00

-3,00

,22

0,46

0,93

n

I  F  -0,08
-0,26

-2,08

I  I
-0,15

-0,05

□  STUK/FI
■  RISO/DK
□  CLOR/PO
□  LVEA/LV
■  ERPC/ES
□  DHIG/GE
□  SSI/SW
□  BFFG/GE

Z-score  of  Cs-137

Figure  A13.
Column  diagram  of
Z-scores  for  Cs-137.

□  STUK/FI
■  RISO/DK
□  CLOR/PO
□  LVEA/LV
■  ERPC/ES
□  DHIG/GE
□  SSI/SW
□  BFFG/GE