ENTRY 23806 20210616 23012380600000001 SUBENT 23806001 20210616 23012380600100001 BIB 13 24 2380600100002 TITLE Long term reactivity changes in natural uranium 2380600100003 reactors 2380600100004 AUTHOR (G.J.Littler) 2380600100005 REFERENCE (C,55GENEVA,5,141,1955) 2380600100006 INSTITUTE (2UK HAR) 2380600100007 REL-REF (R,,,R,AECU-2040,1952) And Supplements. 2380600100008 Cross-section used in analysis 2380600100009 R,,E.E.Locket, unpublished work. CS for Am-140 2380600100010 FACILITY (REAC,2UK HAR) BEPO, the Windscale reactor. 2380600100011 (REAC,1CANCRC) NRX reactor. 2380600100012 (OSCIP) 2380600100013 INC-SOURCE (REAC) 2380600100014 INC-SPECT Integrated fluxes up to 10**20 n/cm2 2380600100015 SAMPLE 42 uranium bars at irradiation in one of 2380600100016 Windscale reactors. 2380600100017 DETECTOR No information in the article. 2380600100018 METHOD Sm-149 was produced as 2380600100019 Nd-149 -> Pm -> 149 -> Sm-149. 2380600100020 Change in effective cross-section per U-235 atom was 2380600100021 measured. It's ratio to fission cross section was 2380600100022 linearly approximated using method of least squares. 2380600100023 DECAY-DATA (60-ND-149,1.7HR) 2380600100024 (61-PM-149,47.HR) 2380600100025 HISTORY (20210616C) M.M. 2380600100026 ENDBIB 24 0 2380600100027 COMMON 1 3 2380600100028 EN-DUMMY 2380600100029 EV 2380600100030 0.0253 2380600100031 ENDCOMMON 3 0 2380600100032 ENDSUBENT 31 0 2380600199999 SUBENT 23806002 20210616 23012380600200001 BIB 6 14 2380600200002 REACTION (92-U-235(N,F)MASS,CHN,FY,,SPA) 2380600200003 ASSUMED (ASSUM,92-U-235(N,F)62-SM-149,,SIG,,SPA) 2380600200004 COMMENT Of authors. We obtained really poisoning yield ( i.e. 2380600200005 the yield of Sm-149 with a cross section of 76700 b) 2380600200006 and we shown that this is the same as the fission yield2380600200007 of the mass 149 chain. 2380600200008 REL-REF A,,J.A.Marinsky+,Radiochemical Studies of the Fission 2380600200009 Products, McGraw-Hill Book Company, INC.Book 2, 1951. 2380600200010 Mass 149 chain yield 1.3+-0.2 %. 2380600200011 (A,,M.C.Inghram+,J,PR,79,271,1950) 2380600200012 1.1 % fission yield at mass number 149. 2380600200013 ERR-ANALYS (DATA-ERR) Type of uncertainty is not explained in the 2380600200014 article. 2380600200015 STATUS (TABLE) Text page 143 of Conf.Proc.58GENEVA,v.5,p.141 2380600200016 ENDBIB 14 0 2380600200017 NOCOMMON 0 0 2380600200018 DATA 4 1 2380600200019 MASS DATA DATA-ERR ASSUM 2380600200020 NO-DIM PC/FIS PC/FIS B 2380600200021 149. 1.00 0.07 76700. 2380600200022 ENDDATA 3 0 2380600200023 ENDSUBENT 22 0 2380600299999 ENDENTRY 2 0 2380699999999