NUREG/CR-5625 (ORNL-6698) - Oak Ridge National Laboratory

Procedure
The technical basis for these characteristics is presented in
Sect. 6.1.
The specific power of cycle i, or e (last cycle), in kW/kgU,
using burnup in MWd/kgU, is defined as
P i
' 1000 B i
0.8 T i
for i < e ;
P e
' 1000 B e
T e
for i ' e .
P ave
'
1000 B tot
.
e & 1
T e
% 0.8 j i ' s
T i
P ave,e & 1
' 1000(B tot & B e )
0.8(T res
& T e
)
.
(2)
The average specific power over the entire operating
history of a fuel assembly, using the same units as in Eq.
(2), is defined as
(3)
The average specific power through the next to last cycle
is used in applying the adjustment factor for short cooling
time (see Sect. 5.2.2). This parameter is defined as
(4)
Note that B tot and P ave , as derived in these definitions, are
used in determining the heat generation rate from the
guide. Also, for cooling times #7 years, P e is used in an
adjustment formula. The method applied here
accommodates storage of a fuel assembly outside the
reactor during one or two cycles and returning it to the
reactor. Then, B i = 0 may be set for all intermediate
storage cycles. If the cooling time is short (i.e.,