ENTRY 14376 20131126 13961437600000001 SUBENT 14376001 20131126 13961437600100001 BIB 10 50 1437600100002 TITLE 55Fe effect on enhancing ferritic steel He/dpa ratio 1437600100003 in fission reactor irradiations to simulate fusion 1437600100004 conditions 1437600100005 AUTHOR (H.Liu,M.A.Abdou,L.R.Greenwood) 1437600100006 REFERENCE (J,FED,88,2860,2013) Analysis 1437600100007 #doi:10.1016/j.fusengdes.2013.05.067 1437600100008 (J,JNM,283-287,(2),1438,2000) Experiment 1437600100009 INSTITUTE (1USACLA,1USABNW) 1437600100010 FACILITY (REAC,1USAORL) 1437600100011 SAMPLE (26-FE-54,ENR=0.96) F-82H alloy composition is 7.1Cr- 1437600100012 1.8W-0.55Si-0.40Mn-0.17V-0.1C-0.04Ta. 54Fe in the 1437600100013 alloy compromised 96% of the iron or 86% of the total 1437600100014 alloy by weight. 1437600100015 PART-DET (A,P) 1437600100016 METHOD (AMS) Alloy samples were analyzed for helium content at1437600100017 Pacific Northwest National Laboratory. The helium 1437600100018 content of each specimen was determined by 1437600100019 isotope-dilution gas mass spectroscopy following 1437600100020 vaporization in a high-temperature vacuum furnace. 1437600100021 Hydrogen measurements were performed using a newly 1437600100022 developed quadrupole mass spectrometer system at PNNL. 1437600100023 An early experiment showed that the 1437600100024 accelerated He(appm)/dpa ratio of about 2.3 was 1437600100025 achieved for 96% enriched 54Fe in iron in the High 1437600100026 Flux Isotope Reactor (HFIR), ORNL. Finally, the 1437600100027 ferritic steel He(appm)/dpa ratio was studied in the 1437600100028 neutron spectrum of HFIR with the 55Fe thermal 1437600100029 neutron helium production taken into account. A 1437600100030 benchmark calculation for the same sample, as used in 1437600100031 the aforementioned experiment, was then used to 1437600100032 adjust and evaluate the 55Fe(n,a) cross section 1437600100033 values in TALYS-based Evaluated Nuclear Data Library. 1437600100034 ANALYSIS Results were, initially, compared to 1437600100035 calculations using isotopic helium production cross 1437600100036 sections from ENDF/B-VI or GNASH and measured neutron 1437600100037 spectra. Finally, the analysis of the benchmark TENDL 1437600100038 calculation showed that a decrease of a factor of 1437600100039 6700 for the TENDL 55Fe(n,a) cross section in the 1437600100040 intermediate and low energy regions was required in 1437600100041 order to fit the experimental results. The best fit 1437600100042 to the cross section value at thermal neutron energy 1437600100043 was about 27 mb. With the adjusted 55Fe(n,a) cross 1437600100044 sections, calculation showed that the 54Fe and 55Fe 1437600100045 isotopes could be enriched by the isotopic tailoring 1437600100046 technique in a ferritic steel sample irradiated in 1437600100047 HFIR to significantly enhance the helium production 1437600100048 rate. This new calculation can be used to guide 1437600100049 future isotopic tailoring experiments designed to 1437600100050 increase the He(appm)/dpa ratio in fission reactors. 1437600100051 HISTORY (20131126C) BP 1437600100052 ENDBIB 50 0 1437600100053 NOCOMMON 0 0 1437600100054 ENDSUBENT 53 0 1437600199999 SUBENT 14376002 20131126 13961437600200001 BIB 2 2 1437600200002 REACTION (26-FE-55(N,A)24-CR-52,,SIG,,,DERIV) 1437600200003 STATUS (TABLE) page 2860. 1437600200004 ENDBIB 2 0 1437600200005 NOCOMMON 0 0 1437600200006 DATA 2 1 1437600200007 EN DATA-APRX 1437600200008 EV MB 1437600200009 0.0253 27.0 1437600200010 ENDDATA 3 0 1437600200011 ENDSUBENT 10 0 1437600299999 ENDENTRY 2 0 1437699999999