Request ID14 Type of the request General request
TargetReaction and processIncident EnergySecondary energy or angleTarget uncertaintyCovariance
 94-PU-242 (n,g),(n,tot) SIG  0.5 eV-2.0 keV  8 Y
FieldSubfieldDate Request createdDate Request acceptedOngoing action
 Fission SFR 06-JUL-07 07-NOV-07 Y

Requester: Dr Gilles NOGUERE at CAD-DER, FR
Email: gilles.noguere@cea.fr

Project (context): JEFF

Impact:
G. Aliberti, G. Palmiotti and M. Salvatores, "The role of differential and integral experiments to meet requirements for improved nuclear data", Int. Conf. on Nuclear Data for Science and Technology, Nice, France, 2007.

Accuracy:
Requested accuracy for nuclear applications is widely discussed within the NEA WPEC Subgroup 26, " Nuclear Data Needs for Advanced Reactor Systems". For Pu-242, the requested accuracy on the capture cross section should be lower than 8% in the fast energy range. Interpretations with JEFF-3.1 of the PROFIL and PROFIL-2 experiments carried out in the fast reactor Phenix have shown the overestimation of about 14% of the capture cross section [1,2].

Justification document:
[1] G. Noguere, E. Dupont, J. Tommasi and D. Bernard, "Nuclear data needs for actinides by comparison with post irradiation experiments", Technical note CEA Cadarache, NT-SPRC/LEPH-05/204 (2005).
[2] J. Tommasi, E. Dupont and P. Marimbeau., "Analysis of Sample Irradiation Experiments in Phénix for JEFF-3.0 Nuclear Data Validation", Nucl. Sci. Eng. 154 (2006) 119-133.
[3] E. Rich, G. Noguere, C. De Saint Jean and O. Serot. "Averaged R-Matrix Modelling of the Pu-242 cross sections in the Unresolved Resonance Range", in Proceedings of the Int. Conf. on Nuclear Data for Science and Technology, Nice, France, 2007.

Comment from requester:
To improve the evaluation of the fast energy range in term of average parameters, new high-resolution capture and transmission measurements are needed. The total cross section above 1.5 keV is poorly known. Accurate average radiation width and strength function are required to solve some ambiguous results obtained between optical model calculations and the statistical analysis of the s-wave resonances [3].

Review comment:
NEA WPEC Subgroup-26 will shortly present more detailed requests related to Pu isotopes that are motivated from sensitivity studies of Generation-IV, GNEP and several reference concepts.

Entry Status:
Work in progress (as of SG-C review of May 2018)
Pending new evaluation or validation (as of SG-C review of June 2019)

Main references:
Please report any missing information to hprlinfo@oecd-nea.org

Experiments

Theory/Evaluation

Validation

Additional file attached:
Additional file attached:Noguere-Pu242-Note-Technique.pdf



Request ID39 Type of the request High Priority request
TargetReaction and processIncident EnergySecondary energy or angleTarget uncertaintyCovariance
 94-PU-242 (n,f) SIG  200 keV-20 MeV  See details Y
FieldSubfieldDate Request createdDate Request acceptedOngoing action
 Fission Fast Reactors 15-SEP-08 15-SEP-08 Y

Requester: Prof. Massimo SALVATORES at CADARACHE, FR
Email: massimo.salvatores@cea.fr

Project (context): CEA Cadarache

Impact:
Design phases of selected reactor and fuel cycle concepts require improved data and methods in order to reduce margins for both economical and safety reasons. A first indicative nuclear data target accuracy assessment was made within WPEC Subgroup 26 (SG-26). The assessment indicated a list of nuclear data priorities for each of the systems considered (ABTR, SFR, EPR, GFR, LFR, ADMAB, VHTR, EPR). These nuclear data priorities should all be addressed to meet target accuracy requirements for the integral parameters characterizing those systems (see the accompanying requests originating from SG-26).

Accuracy:
Target accuracies are specified per system and per energy group when they are not met by the BOLNA estimate of the current (initial) uncertainties. The weighting factor λ is explained in detail in the accompanying document. Changes from the reference value of λ=1 show the the possible allowance for other target uncertainties. Two cases (A and B) are distinguished for λ≠1 (see Table 24 of the report).

Energy RangeInitial versus target uncertainties (%)
InitialSFREFRGFRLFRADMAB
λ=1 λ≠1,b λ=1 λ≠1,a λ=1 λ≠1,a λ=1 λ≠1,a λ=1
6.07 - 19.6 MeV 37 15 14
2.23 - 6.07 MeV 15 5 5 6 6 7 8 7
1.35 - 2.23 MeV 21 5 4 5 6 7 7 5
0.498 - 1.35 MeV 19 4 3 11 9 4 4 4 4 4
183 - 498 keV 19 9 8

Justification document:
OECD/NEA WPEC Subgroup 26 Final Report: "Uncertainty and Target Accuracy Assessment for Innovative Systems Using Recent Covariance Data Evaluations" (link to WPEC Subgroup 26 Report in PDF format, 6 Mb).

Comment from requester:
Given the present state of knowledge the above target accuracies are very tight. However, any attempt that significantly contributes to reducing the present accuracy for this quantity is strongly encouraged. Any such attempt will significantly enhance the accuracy with which reactor integral parameters may be estimated and will therefore impact economic and safety margins.

Review comment:

Entry Status:
Work in progress (as of SG-C review of May 2018)

Main references:
Please report any missing information to hprlinfo@oecd-nea.org

Experiments

Theory/Evaluation

  • M. Herman et al., COMMARA-2.0 Neutron Cross Section Covariance Library, Report BNL-94830-2011, Brookhaven National Laboratory (2011)
  • Pu-242 evaluation was proposed to be part of INDEN (CIELO follow-up) initial program of work (as of Dec. 2017)

Validation

Additional file attached:SG26-report.html
Additional file attached: