| Request ID | 4 | Type of the request | High Priority request | ||
|---|---|---|---|---|---|
| Target | Reaction and process | Incident Energy | Secondary energy or angle | Target uncertainty | Covariance |
| 92-U-235 | (n,f) prompt g | Thermal-Fast | Eg=0-10MeV | 7.5 | Y |
| Field | Subfield | Created date | Accepted date | Ongoing action | Archived Date |
| Fission | LWR, Gen-IV | 10-MAY-06 | 12-MAY-06 | Y | 19-MAY-22 |
Send a comment on this request to NEA.
Requester: Prof. Gerald RIMPAULT at CAD-DER, FR
Email: gerald.rimpault@outlook.fr
Project (context): JEFF, NEA WPEC Subgroup 27
Impact:
Accuracy:
Justification document:
Comment from requester:
Additional file attached: HPRLgammafission.pdf
Review comment:
Entry Status:
Main recent references: Experiments Theory/Evaluation
The four fast reactor systems of GenIV feature innovative core characteristics for which gamma-ray heating estimates for non-fuel zones require an uncertainty of 7.5% [1]. For the experimental Jules Horowitz Reactor (RJH) at Cadarache a similar requirement appears [2]. Recent studies show evidence of discrepancies on integral measurement in MASURCA, EOLE and MINERVE, from which it is clear that the expectations for GenIV systems and the RJH thermal reactor are not met [3]. Gamma-ray energy release is dominated by Pu-239 and U-235.
7.5% on the total gamma energy
7.5% on multiplicity
Best accuracy achievable for the gamma spectrum shape
Reference 1: G. Rimpault, Proc. Workshop on Nuclear Data Needs for Generation IV, April 2005, Antwerp, Belgium
Reference 2: D. Blanchet, Proc. M&C 2005, Int. Topical Meeting on Mathematics and Computation, Supercomputing, Reactor Physics and Nuclear and Biological Applications, Sep. 2005, Avignon, France
Reference 3: 'Needs for accurate measurements of spectrum and multiplicity of prompt gammas emitted in fission', G. Rimpault, A. Courcelle and D. Blanchet, CEA/Cadarache – DEN/DER/SPRC.
Forty percent of the total gamma-ray energy release results from prompt decay of fission products. No comprehensive analytic expressions exist and Hauser-Feshbach model calculations are involved and presently lack sufficient knowledge to warrant a solution of the problem. New measurements would be needed to guide new evaluation efforts. Present evaluations are based on measurements from the seventies.
Discrepancies observed for C/E ratios in various benchmarks range from 10 to 28%. The request is well motivated and based on a considerable effort.
Work in progress (as of SG-C review of May 2018)
Pending new evaluation or validation (as of SG-C review of June 2019)
Pending new evaluation or validation (as of SG-C review of May 2021) with recommendations for priority validation of the latest evaluations
Completed (as of SG-C review of May 2022) - The characteristics of the PFGS have been measured at thermal and fast energies for both U-235 and Pu-239. Experimental data have been combined with model calculations to evaluate the prompt gamma properties as a function of incident neutron energy for JEFF-3.3 and ENDF/B-VIII.0.
Please report any missing information to hprlinfo@oecd-nea.org
