Request ID	29		Type of the request	High Priority request
Target	Reaction and process	Incident Energy	Secondary energy or angle	Target uncertainty	Covariance
11-NA-23	(n,inl) SIG	0.5 MeV-1.3 MeV	Emis spec.	See details	Y
Field	Subfield	Date Request created	Date Request accepted	Ongoing action
Fission	Fast Reactors (SFR)	04-APR-08	12-SEP-08	Y

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

Project (context): NEA WPEC Subgroup 26

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).

Requested accuracy is required to meet target accuracy for void coefficient 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).

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.

Energy Range Target versus initial uncertainties (%)

Initial ABTR SFR EFR

1.35 - 2.23 MeV 13 9

0.498 - 1.35 MeV 28 10 4 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)
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

C. Rouki et al., High resolution measurement of neutron inelastic scattering cross-sections for 23Na, NIM A 672 (2012) 82, EXFOR 23137
J.R. Vanhoy et al., Neutron scattering differential cross-sections for 23Na from 1.5 to 4.5 MeV, Nucl. Phys. A 939 (2015) 121, EXFOR 14403

Theory/Evaluation

S. Kopecky and A. Plompen, R-matrix analysis of the total and inelastic scattering cross sections, EUR 25067 EN (2011)
M. Herman et al., COMMARA-2.0 Neutron Cross-Section Covariance Library, Report BNL- 94830-2011, Brookhaven National Laboratory (2011)
P. Archier et al., New JEFF-3.2 Sodium Neutron Induced Cross-sections Evaluation for Neutron Fast Reactors Applications: from 0 to 20 MeV, NDS 118 (2014) 140
D. Rochman et al., On the evaluation of 23Na neutron-induced reactions and validations, NIM A 612 (2010) 374
Ongoing evaluation work in the framework of INDEN (CIELO follow-up), see Summary Report of the IAEA CM, 15-17 May 2019, Vienna, Report INDC(NDS)-0788

Validation

M. Salvatores, et al., Methods and Issues for the Combined Use of Integral Experiments and Covariance Data: Results of a NEA International Collaborative Study, Nuclear Data Sheets 118 (2014) 38
G. Palmiotti, et al., Combined Use of Integral Experiments and Covariance Data, Nuclear Data Sheets 118 (2014) 596
Y.-K. Lee, E. Brun, Investigation of Nuclear Data Libraries with TRIPOLI-4 Monte Carlo Code for Sodium-cooled Fast Reactors, Nuclear Data Sheets 118 (2014) 433

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

Request ID 69 Type of the request Special Purpose Quantity

Target Reaction and process Incident Energy Secondary energy or angle Target uncertainty Covariance

11-NA-23 (n,2n) SIG,SPA 252Cf(sf)-235U(n,f) 2-5 Y

Field Subfield Date Request created Date Request accepted Ongoing action

Dosimetry D-T fusion 06-OCT-17 06-OCT-17

Requester: Dr Stanislav SIMAKOV at KARLSRUHE, GER
Email: stanislav.simakov@partner.kit.edu

Project (context): IRDFF project

Impact:
The International Reactor Dosimetry and Fusion File (IRDFF) aims at providing evaluated neutron dosimetry reactions validated for all applications related to fission reactors and fusion technology development [IAEA2017].

Accuracy:
2%-5%

Justification document:
Accurate cross sections as well as spectrum-averaged cross sections (SACS) in relevant and well-characterized neutron fields are essential for improvement and validation of the evaluated data [Simakov2017].
Following a recommendation from the IAEA Data Development Project on Neutron Standards [Pronyaev2013], the IRDFF project supports SACS measurements of high-threshold (above 10 MeV) dosimetry cross-sections in well-characterized 252Cf(sf) and 235U(nth,f) neutron fields in order to improve the cross sections and/or the high-energy part of the prompt fission neutron spectra.

Comment from requester:
Measurements of the spectrum-averaged cross section are missing for validation purposes and for improvement of the cross section and prompt fission neutron spectrum above 10 MeV. See Cf252U235_HighThreshold.pdf below.

References

[IAEA2017] IAEA CRP on Testing and Improving the International Reactor Dosimetry and Fusion File (IRDFF),
http://www-nds.iaea.org/IRDFFtest/.
[Simakov2017] S. Simakov, et al., “Proposals for new measurements for IRDFF community and HPRL”, September 2017.
[Pronyaev2013] V.G. Pronyaev, A.D. Carlson and R. Capote Noy, “Toward a New Evaluation of Neutron Standards”, IAEA Technical Meeting, 8-12 July 2013, INDC(NDS)-0641.

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

M. Schulc, M. Kostal, et al., Validation of differential cross sections by means of 252Cf spectral averaged cross sections, Applied Radiation and Isotopes 132 (2018) 29
M. Schulc, et al., Investigation of 127I(n,2n)126I and 23Na(n,2n)22Na reactions using 252Cf neutron source, ASME J of Nuclear Rad Sci. 5 (2019) 030918
M. Kostal, et al., A reference neutron field for measurement of spectrum averaged cross sections, Annals of Nuclear Energy 140 (2020) 107119

Theory/Evaluation

A. Trkov et al., IRDFF-II: A New Neutron Metrology Library, Nuclear Data Sheets 163 (2020) 1

Additional file attached:Simakov2017.pdf
Additional file attached:Cf252U235_HighThreshold.pdf

Energy Range	Target versus initial uncertainties (%)
	Initial	ABTR	SFR	EFR
1.35 - 2.23 MeV	13		9
0.498 - 1.35 MeV	28	10	4	8

Request ID	69		Type of the request	Special Purpose Quantity
Target	Reaction and process	Incident Energy	Secondary energy or angle	Target uncertainty	Covariance
11-NA-23	(n,2n) SIG,SPA	252Cf(sf)-235U(n,f)		2-5	Y
Field	Subfield	Date Request created	Date Request accepted	Ongoing action
Dosimetry	D-T fusion	06-OCT-17	06-OCT-17