Request ID | 113 | Type of the request | Special Purpose Quantity | ||
---|---|---|---|---|---|
Target | Reaction and process | Incident Energy | Secondary energy or angle | Target uncertainty | Covariance |
69-TM-169 | (n,2n) SIG/SPA | 239Pu(n,f) | 3 | Y | |
Field | Subfield | Created date | Accepted date | Ongoing action | Archived Date |
Fission | Dosimetry | 26-MAR-18 | 06-JUN-18 |
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Requester: Dr Roberto CAPOTE NOY at IAEA, AUT
Email: roberto.capotenoy@iaea.org
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Justification document: References
Comment from requester:
Review comment:
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A better knowledge of the prompt fission neutron spectrum (PFNS) from Pu-239 thermal-neutron induced fission is important for high-burnup fuels and new generation reactors. This is especially true when considering neutron radiation damage from the PFNS high-energy tail, which can be improved thanks to the measurements of spectrum-averaged cross section (SACS) of well-known high-threshold dosimetry reactions.
Deficiency in Pu-239(n,f) PFNS at large outgoing energies may be responsible for the discrepancies shown in Fig. 178 above 7.5 MeV of average reaction energy, see Fig. 178 in Ref. [1].
3% cross-section ratio uncertainty relative to reference cross sections
No SACS measurements exist in Pu-239(nth,f) prompt neutron field. In the latest IAEA evaluation, the extrapolation of Pu-239(nth,f) PFNS to outgoing energies above 8 MeV is based on SACS estimated by interpolation between SACS measured in U-233, U-235 and Cf-252 prompt neutron fields, see page 74-76, Fig. 43 and Table XXVI in Ref. [2].
SACS measurements of high-threshold dosimetry reactions are requested to improve further the high-energy tail of Pu-239(nth,f) PFNS above 8 MeV of outgoing energy. These measurements should be performed relative to high-threshold reference cross sections: Al-27(n,a), Au-197(n,2n), Ni-58(n,p).
Work in progress (as of SG-C review of June 2019)
Please report any missing information to hprlinfo@oecd-nea.org