Regional Basic Professional Training Course in Korea

Regional Basic Professional Training Course (BPTC) on Nuclear Safety
temporal component that must be considered. Both ICRP and NCRP recommend the use
of the committed equivalent dose H T (τ) as the time integral of equivalent dose rate in a
specific tissue (T) after the deposition of the radioactive material has occurred. For a
single radionuclidic deposition at time t0:
.
Where T
t0
+ τ
HT ( τ)
= ∫ H T
t
❙ 70 ❙
0
.
( t)
dt
H is the equivalent dose rate in the organ or tissue T at time t and τ is the
integration period to be taken as 50 y (fifty years) after intake for a
radiation worker and 70y for a child. The committed effective dose E(τ) given by:
τ ) = ∑ WT
H ( τ)
E( T
is just the sum for each internally deposited radionuclide of the appropriate tissue
weighting factor multiplied by the committed equivalent dose. When τ is taken to be 50 y
the above equation is written for a radiation worker as:
E ( 50
)
∑ = T j
m T H
w w
H +
=
T ( 50 )
T k
T Tremaninde r
T 1
T= i
∑ m
T
T = 1
∑
= =
T = k
T
T
( 50 )
Where HT (50) is the committed equivalent dose and WT the specific weighting factor for
the tissues(Ti to Tj) specifically named in Table 2.2 and mT is the mass of the named
remainder organs (Tk to T1). If half of the original radionuclide is eliminated from the
body in three months or less, then the committed equivalent and effective dose reflect
very closely the annual equivalent and effective dose for the year of intake. If however,
the radionuclide leaves the body more slowly, these quantities actually overestimate the
equivalent and effective dose received in the year of intake because a significant portion