**WPEC SG 21: Assessment of Neutron Cross-Section Evaluations for the
Bulk of Fission Products**

**54-Xe-136 Review**

Drafted by ZHUANG Youxiang, CNDC, January 22, 2003

# Files

**ENDF/B-VI:** Year of origin 1978, taken from ENDF/B-V, no revisions
since then

**JEF-2:** Year of origin 1982, data taken mostly from ENDF/B-V, last
revision 1989

**JENDL-3:** Year of origin 1990, last revision 1990

**CENDL-3:** Year of origin 2000, last revision 2001

# Thermal and resonance region

**ENDF/B-VI:** No resonance parameters given except AP, scattering

radius 5.85 fm.

**JEF-2:** No resonance parameters given except AP, scattering

radius 5.85 fm.

.

**JENDL-3, CENDL-3:** Resolved resonance parameters up to 490 keV,
scattering radius

6.00 fm, no unresolved resonance given (Table 1).

JENDL-3, CENDL-3 perform better in the resonance region with no
"backgroumd" in File 3.

**Recommendation/Conclusion:** **JENDL-3 or CENDL-3** recommended in
thermal and resonance

region up to 490 keV.

# Fast neutron region

·Methodology

**ENDF/B-VI, JEF-2:** Spherical OM for MT=1; capture from NCAP code;
inelastic cross sections

(MF=3, MT=4, 51-91) from COMNUC-3 code, no pre-equilibrium corrections.
MT=1, 2, 4, 16, 17,

51-53, 91, 102\~105, 107.

**JENDL-3:** Spherical OM and statistical model code CASTHY for MT=1, 4,
51-91, 102 by

taking into account competing reactions MT=16, 17, 103, 107 calculated
with the pre-equilibrium

and multi-step evaporation model code PEGASUS. Direct and semi-direct
capture estimated;

elastic calculated as (MT1 -- sum of partial cross sections); Legendre
coefficients from CASTHY

to get unisotropic angular distribution for MF=4, MT=2 in CM system.
MT=1, 2, 4, 16, 17, 22, 28,

51-64, 91, 102\~105, 107.

**CENDL-3:** Spherical OM and unified pre-equilibrium-statistical model
code SUNF; DWBA code

DWUCK4 to calculate direct inelastic scattering. MT=1, 2, 4, 16, 17, 22,
28, 51-67, 91, 102\~105,

107\.

·MT=4

**CENDL-3:** Increase of (n,n') compared to JENDL-3 probably due to
direct inelastic scattering

accounted for by DWUCK4. It is reasonable from neighbor natural elements
of Ce, La and Sb.

**Recommendation/Conclusion:** **CENDL-3** or **JENDL-3** recommended in
fast energy region

490 keV - 20 MeV; **CENDL-3** probably somewhat better (accounting for
direct inelastic scattering).

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

**Table 1.** Summary for Resolved and Unresolved Resonance Region:
Xe-136

+---------+-----+-------------+------+-----+-------------------------+
| Library | Y   | First       | RRR  | URR | Remarks                 |
|         | ear | Authors     |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+
| EN      | 1   | Bhat ,      | \-   | \-  |                         |
| DF/B-VI | 978 |             |      |     |                         |
|         |     | Mughabghab  |      |     |                         |
|         |     |             |      |     |                         |
|         |     | (NNDC)      |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+
| JEF-2   | 1   | Gruppelaar, | \-   | \-  |                         |
|         | 982 |             |      |     |                         |
|         |     | Menapace    |      |     |                         |
|         |     |             |      |     |                         |
|         |     | (NEA)       |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+
| JENDL-3 | 1   | JNDC FP     | 490  | \-  | RR parameters were      |
|         | 990 |             | keV  |     | evaluated for JENDL-3.  |
|         |     | Nuclear     |      |     |                         |
|         |     | Data        | MLBW |     |                         |
|         |     |             |      |     |                         |
|         |     | Working     |      |     |                         |
|         |     |             |      |     |                         |
|         |     | Group       |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+
| CENDL-3 | 2   | Shen        | 490  | \-  | RR parameters taken     |
|         | 000 | Qing-Biao   | keV  |     | from JENDL-3.           |
|         |     |             |      |     |                         |
|         |     | Yu          | MLBW |     |                         |
|         |     | Bao-Sheng,  |      |     |                         |
|         |     |             |      |     |                         |
|         |     | (CNDC)      |      |     |                         |
|         |     |             |      |     |                         |
|         |     | Zhang       |      |     |                         |
|         |     | Zheng-Jun,  |      |     |                         |
|         |     |             |      |     |                         |
|         |     | Sun         |      |     |                         |
|         |     | Xiu-Quan    |      |     |                         |
|         |     |             |      |     |                         |
|         |     | (UNW)       |      |     |                         |
+---------+-----+-------------+------+-----+-------------------------+

**Table 2.** Thermal Cross Sections for Xe-136

+---------------------------+-------------+-------------+-------------+
| Library / Experiment      | Total       | Capture     | Elastic     |
+---------------------------+-------------+-------------+-------------+
| ENDF/B-VI                 | 4.46054 b   | 0.160 b     | 4.30054 b   |
+---------------------------+-------------+-------------+-------------+
| JEF-2                     | 4.46054 b   | 0.160 b     | 4.30054 b   |
+---------------------------+-------------+-------------+-------------+
| JENDL-3                   | 6.348 b     | 0.260 b     | 6.088 b     |
+---------------------------+-------------+-------------+-------------+
| CENDL-3                   | 6.348 b     | 0.260 b     | 6.088 b     |
+---------------------------+-------------+-------------+-------------+
| BNL-325 (1981)            |             | 0.26±       |             |
|                           |             |             |             |
|                           |             | 0.02 b      |             |
+---------------------------+-------------+-------------+-------------+
| S.F.Mughabghab,           |             | 0.26±       |             |
| INDC(NDS)-424,            |             |             |             |
|                           |             | 0.02 b      |             |
| \(2001\)                  |             |             |             |
+---------------------------+-------------+-------------+-------------+