| Request ID | 7 | Type of the request | General request | ||
| Target | Reaction and process | Incident Energy | Secondary energy or angle | Target uncertainty | Covariance |
| 26-FE-56 | (n,xn) SIG,DDX | 7 MeV-20 MeV | 1MeV-20MeV | 30 | |
| Field | Subfield | Date Request created | Date Request accepted | Ongoing action | |
| Fission,ADS | Shielding, Medical, SNS | 13-JUL-06 | 16-APR-07 | ||
Requester: Prof. Arjan KONING at NRGPETTEN, NED
Email:
Project (context): JEFF, Model calculations
Impact:
Accuracy:
Justification document:
Comment from requester:
Review comment:
Entry Status:
Main references: Experiments Theory/Evaluation Additional file attached:
Requester: Prof. Massimo SALVATORES at CADARACHE, FR
Project (context): NEA WPEC Subgroup 26
Impact:
Accuracy:
Justification document:
Comment from requester:
Review comment:
Entry Status:
Main references: Experiments Theory/Evaluation Validation Additional file attached:SG26-report.html
New double differential experimental data for the Fe(n,xn) reaction will allow a crucial test of the pre-equilibrium models underlying neutron transport libraries for spallation neutron sources. They will thereby enhance the confidence in neutron transport calculations for spallation neutron sources such as envisioned for accelerator driven systems.
30% for the double-differential spectra
A global pre-equilibrium analysis from 7 to 200 MeV based on the optical model potential, A.J. Koning and M.C. Duijvestijn,
Nucl. Phys. A744, 15 (2004).
There are hundreds of (p,xp) and (p,xn) spectra in the 20-200 MeV range available, several (n,xp) spectra, but there are basically no
double-differential (n,xn) spectra available. The presence of such data would heavily constrain the pre-equilibrium model parameters and thereby result in a much better prediction of neutron-induced spectra in the entire 50-200 MeV range. Since high-energy spectra are rather structureless the choice of target is less essential.
Completed (as of SG-C review of May 2018) - The experimental program performed at Uppsala [Sagrado:2011] combined with improvements in nuclear reaction models allow modern evaluations to address this request, see e.g. [Herman:2018].
Please report any missing information to hprlinfo@oecd-nea.org
Additional file attached:
Request ID 34
Type of the request High Priority request
Target Reaction and process Incident Energy Secondary energy or angle Target uncertainty Covariance
26-FE-56 (n,inl) SIG 0.5 MeV-20 MeV Emis spec. See details Y
Field Subfield Date Request created Date Request accepted Ongoing action
Fission ADMAB and SFR 04-APR-08 12-SEP-08 Y
Email:
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).
Somewhat different requested accuracy is required to meet target accuracies for keff, peak power and void coefficient for the Accelerator-Driven Minor Actinides Burner (ADMAB) and for keff for the Sodium-cooled Fast Reactor in a TRU burning configuration, i.e., with a Conversion Ratio CR<1 (SFR). Details are provided in the 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).
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 Range Initial versus target uncertainties (%) Initial ABTR SFR EFR LFR ADMAB λ=1 λ≠1,a λ≠1,b λ=1 λ≠1,a λ≠1,b λ=1 λ≠1,a λ=1 λ≠1,a λ=1 λ≠1,a
6.07 - 19.6 MeV 13 9 11 13 2.23 - 6.07 MeV 7 4 5 7 3 3 1.35 - 2.23 MeV 25 6 7 10 3 4 7 7 7 4 6 2 2 0.498 - 1.35 MeV 16 8 9 13 3 4 6 8 9 4 5 2 2
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).
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.
Experimental work was recently completed at IRMM. The impact of the new experimental results is studied at CEA/Cadarache. Uncertainties below 5% will require a major further improvement.
Work in progress (as of SG-C review of May 2018)
Please report any missing information to hprlinfo@oecd-nea.org
Additional file attached: