ID | 38 |
---|---|
Type | |
Target | 94-Pu-240 |
Reaction | (n,f) |
Quantity | nubar - Average prompt neutron emission multiplicity |
Incident energy | 200 keV - 2 MeV |
Accuracy | 1-3 % |
Field(s) | Fission |
Subfield | Fast Reactors |
Accepted date | 15-Sep-2008 |
Status | Work in progress |
Latest review date | 22-Apr-2022 |
Prof. Massimo SALVATORES at CADARACHE, FR
Project (context)CEA Cadarache
ImpactDesign 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).
AccuracyTarget 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 | SFR | EFR | GFR | LFR | ADMAB | |||||||
λ=1 | λ≠1,a | λ≠1,b | λ=1 | λ≠1,a | λ=1 | λ≠1,a | λ=1 | λ≠1,a | λ=1 | λ≠1,a | ||
1.35 - 2.23 MeV | 3 | 2 | 2 | 2 | ||||||||
0.498 - 1.35 MeV | 4 | 2 | 2 | 1 | 3 | 2 | 2 | 2 | 1 | 1 | 2 | 2 |
183 - 498 keV | 5 | 3 | 3 | 3 | 3 | 3 |
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 requesterGiven 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.
Entry statusWork in progress (as of SG-C review of May 2018)
Main recent referencesPlease report any missing information to hprlinfo@oecd-nea.org
Theory/Evaluation
Validation