[WPEC SG21: Assessment of Neutron Cross-Section Evaluations for the Bulk
of Fission Products]{.underline}

59-Pr-142 Review

Pavel Oblozinsky, BNL, August 2003

### **1. General**

### 

### **Properties:** Unstable nucleus, half-life T~1/2~ = 19.12 h.

### 

**EXFOR data**

Complete lack of experimental data.

### **Evaluations**

ENDF/B-VI Year of origin 1974, by Schenter & Schmittroth (ORNL).

JEF-2 Year of origin 1982, taken from ENDF/B-V with some additions,
charged particle production added from REAC-ECN-4 library, by
Coordination Group.

BROND-2 None.

JENDL-3 None.

CENDL-3 None.

### **2. Thermal and resonance region**

For summary, see Table 1 and 2.

**ENDF/B-VI**

-   No resonance parameters given (except of AP) due to complete lack of
    experimental data.

**JEF-2**

-   As above.

**Recommendation/Conclusion**

ENDF/B-VI and JEF-2 are identical. **ENDF/B-VI is recommended** as
original evaluation.

**[3. Fast neutron region]{.underline}**

#### ENDF/B-VI methodology

-   Dates back to 1974, evaluation taken over from ENDF/B-V.

-   Simple statistical model, Moldauer OM parameterization.

##### JEF-2 methodology

-   Taken over from ENDF/B-VI (1974 evaluation by Schenter &
    Schmittroth).

-   Charged particle production from REAC-ECN-4 library.

**Comparison of evaluations**

-   MT=1 Complete lack of data**,** ENDF/B-VI has reasonable shape,
    JEF-2 is the same.

-   MT= 4 ENDF/B-VI looks somewhat unrealistic, but nothing better is
    available. JEF-2 is

> the same.

-   MT=16 Not available.

-   MT=102 ENDF/B-VI has reasonable shape. JEF-2 is the same.

-   MT=103 Only JEF-2 available.

-   MT=107 Only JEF-2 available.

###### Recommendation/Conclusion

> There is complete lack of experimental data. JEF-2 is more complete,
> though otherwise it is taken from ENDF/B-V. **JEF-2 is recommended**.

Table 1. Thermal cross sections, resonance integral and one-group
capture values for Pr-142.

+----------------+-------+--------+-------+--------------+-----------+
| **\            | #     | # C    | # El  | # Re         | #         |
| Source**       | Total | apture | astic | sonance Capt | One-group |
|                |       |        |       | ure Integral |           |
|                | **(ba | **(b   | **(ba |              | # Capture |
|                | rn)** | arn)** | rn)** | **(barn)**   |           |
|                |       |        |       |              | **(barn)  |
|                |       |        |       |              | \[2\]**   |
+----------------+-------+--------+-------+--------------+-----------+
| #              | #     | #      | #     | # 4.69E-1    |           |
|  ENDF/B-VI20.0 |  20.0 |        | 145.3 |              |           |
+----------------+-------+--------+-------+--------------+-----------+
| JEF-2          | 20.0  | 20.0   |       | 145.3        | 4.68E-1   |
+----------------+-------+--------+-------+--------------+-----------+
| Mughabghab     |       | none   |       |              |           |
| 2003 \[1\]     |       |        |       |              |           |
+----------------+-------+--------+-------+--------------+-----------+
| BNL-325 (1981) |       | 20 (3) |       |              |           |
+----------------+-------+--------+-------+--------------+-----------+

**Table 2**. Summary of resolved and unresolved resonance region for
Pr-142.

+---------+-----+---------+---------+--------+-----------------------+
| **Li    | **  | **First | **RRR\  | # URR  | **Remarks**           |
| brary** | Yea | Author\ | **      |        |                       |
|         | r** | **      |         |        |                       |
+---------+-----+---------+---------+--------+-----------------------+
| ENDF/B  | Sc  | None    | #       | No     |                       |
| -VI1974 | hen |         |         | res    |                       |
|         | ter |         |         | onance |                       |
|         |     |         |         | para   |                       |
|         |     |         |         | meters |                       |
|         |     |         |         | given. |                       |
+---------+-----+---------+---------+--------+-----------------------+
| JEF-2   | 1   | S       | None    | #      | Taken from ENDF/B-V.  |
|         | 974 | chenter |         |        |                       |
+---------+-----+---------+---------+--------+-----------------------+

#### References

1.  S.F. Mughabghab, Thermal neutron capture cross sections, resonance
    integrals and g-factors, Report INDC (NDS)-440 (IAEA, Vienna,
    February 2003).

2.  H. Gruppelaar et al, Status of pseudo-fission-product cross sections
    for fast reactors, Final Report of Subgroup 17, Report NEA/WPEC-17,
    ECN-R-98-014 (NEA, Paris, 1998). Recalculated systematically for all
    211 FP and all 5 evaluated libraries by I. Sirakov (BNL, 2002), see
    <http://www.nndc.bnl.gov/sg21/nucl/acs/accs.htm>.