International Reactor Dosimetry File 2002 - IAEA Publications

Fluence rate per unit energy (m –2·s –1·MeV –1 )
10 20
10 18
10 16
10 14
10 12
10 10
10 8
10
10 –10 10 –9 10 –8 10 –7 10 –6 10 –5 10 –4 10 –3 10 –2 10 –1 10 0 10 1 10 2
6
Energy (MeV)
10 14
Fluence rate per unit lethargy (m –2·s –1 )
10 13
10 12
10
10 –10 10 –9 10 –8 10 –7 10 –6 10 –5 10 –4 10 –3 10 –2 10 –1 10 0 10 1 10 2
11
Energy (MeV)
FIG. 3.1. Neutron spectrum MTR in two different representations, as used in the
uncertainty calculations [3.6].
IRDF-90 and the other libraries of interest, while the related uncertainty
information can vary with the source of data. Reactions exhibiting this
behaviour are 23 Na(n,γ) 24 Na (IRDF-90 and ENDF/B-VI), 55 Mn(n,γ) 56 Mn
(IRDF-90 and JENDL/D-99), 63 Cu(n,γ) 64 Cu (IRDF-90 and ENDF/B-VI),
93 Nb(n,γ) 94 Nb (IRDF-90 and ENDF/B-VI), 115 In(n,γ) 116 In m (IRDF-90 and
ENDF/B-VI) and 232 Th(n,γ) 233 Th (IRDF-90 and ENDF/B-VI). IRDF-90 was
taken as the source of data for IRDF-2002 in these particular cases.
Considering the 58 Fe(n,γ) 59 Fe reaction: the resonance integral in both
cross-section files of interest (IRDF-90 and JENDL/D-99) deviates significantly
from the corresponding data of Mughabghab, while the JENDL/D-99
value is in good agreement with the data of Holden (as compared with the
relevant uncertainties). Further clarification is required, for example, by
19