INDC(IND)-35G - IAEA Nuclear Data Services
INDC(IND)-35G - IAEA Nuclear Data Services
INDC(IND)-35G - IAEA Nuclear Data Services
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2*? 9<br />
Generation of Doppler broadened Cross Sections for Pu,<br />
238 U. 2 3 V 2ft0 PU. 2ttl Pu. 2 * 2 Pu. Fe. Cr. Hi. Mn. Mo. Na<br />
for Hi^ier Temperature for use in Accident Analysis<br />
(M.M. Ramanadhan, V. Gopalakrishnan and S. Ganesan)<br />
Doppler broadened cross sections to temperatures<br />
varying from 300 K to 4500 K were generated for various<br />
fissile, fertile and structural materials usinp the preprocessing<br />
code LINEAR-RECENT and SJGMA1 . Self shielded<br />
2<br />
cross sections were obtained by using the program REX2 .<br />
Summarised below are the steps adapted for obtaining<br />
the cross sections for various elements*<br />
1* Using: code * LINEAR 1 , the evaluated cross sections of<br />
the particular elements from the ENDF/B-IV file, were<br />
linearised to high precision (0.1$).<br />
2. The above linearised data was reconstructed to a reasonable<br />
precision by using code 'RECENT 1 .<br />
218 219<br />
3. For materials like J V and J? Pu which had large data<br />
points, the output obtained from the code RECENT was<br />
further thinned using LINEAR code to an acceptable<br />
precision before going to step h. For the other materials<br />
step h was directly followed.<br />
k. Using the code SIGMA1 the above eross sections were Doppler<br />
broadened to 300 K with 0.0 thinning criteria.<br />
For broadening to temperatures higher than 300 K, one<br />
thinned output for 300 K was taken as input and cross sections<br />
were obtained at a number of temperatures. Since the running<br />
time of code SIGMA1 depends on the number of points input to it<br />
this method of going to higher temperatures was adapted. The<br />
preprocessing experience in the case of U-238 is detailed by<br />
• flow chart in Fig.l.<br />
The doppler broadened outputs were input to the program<br />
REX2 for obtaining the self shielded cross sections.