ENTRY 23704 20200505 22882370400000001 SUBENT 23704001 20200505 22882370400100001 BIB 8 31 2370400100002 TITLE Radiochemical investigation of 238U spontaneous fission2370400100003 AUTHOR (M.N.Rao) 2370400100004 REFERENCE (J,RCA,8,12,1967) 2370400100005 INSTITUTE (2GERKLN) 2370400100006 SAMPLE .Pitchblende from Eldorado Mines, Great Bear Lake, 2370400100007 Canada, ~50% U(3)O(8) - for long-lived nuclides. 2370400100008 300 g - for Sr. 2370400100009 .Pure UO(2)(NO(3))2*6H(2)O . 2370400100010 900 g for Cs, 2.3 kg for Ba. 2370400100011 DETECTOR Phillips low-background assembly of pancake type 2370400100012 G.M.Sonde 18516 Sample counter with a Fe-Cr window of 2370400100013 10 mg/cm2 thickness. A stainless steel dome shaped 2370400100014 anti-coincidence umbrella, filled with Ar and halogen 2370400100015 quencher - as ring counter. 2370400100016 Counting efficiency was determined by Sr-90, Y-90, 2370400100017 P-32, Na-22 samples of various thickness with 2370400100018 uncertainty 10-15 %. 2370400100019 METHOD (CHSEP) 2370400100020 Sr-89 Sr-90 Cs-136 Cs-136 Ba-139 2370400100021 U-238,kg 0.173 0.173 0.763 0.371 1.12 2370400100022 Chem.yield,% 50.4 50.4 30.3 28.2 45.1 2370400100023 Counting efficiency,% 35.0 13.5 37.5 38.0 35.2 2370400100024 +- +- +- +- +- 2370400100025 1.0 0.3 1.0 1.0 0.9 2370400100026 Activity at t=0,cpm 0.5 0.3 2.8 1.3 4.8 2370400100027 +- +- +- +- +- 2370400100028 0.2 0.1 0.5 0.3 0.8 2370400100029 Equilibrium activity, 2.7 4.3 5.5 5.6 4.5 2370400100030 dis/sec/gU x10**-4 +- +- +- +- +- 2370400100031 0.9 1.4 1.1 1.2 1.0 2370400100032 HISTORY (20200520C) M.M. 2370400100033 ENDBIB 31 0 2370400100034 NOCOMMON 0 0 2370400100035 ENDSUBENT 34 0 2370400199999 SUBENT 23704002 20200520 22882370400200001 BIB 5 26 2370400200002 REACTION 1(92-U-238(0,F)MASS,CHN,FY) 2370400200003 2(92-U-238(0,F)MASS,CHN,FY,,,DERIV) 2370400200004 ANALYSIS 1. Yield was calculated as 2370400200005 (NiLAMBLAi/(N238*LAMBLAsf))*100, where 2370400200006 NiLAMBLAi - equilibrium activity of the fission product2370400200007 with mass number i, 2370400200008 N238 - number 0f U-238 atoms, 2370400200009 LAMBDAsf - U-238 spontaneous fission decay constant, 2370400200010 (7.8+-0.9)*10**17 1/yr. 2370400200011 2nd run - (3.96+-0.4)*10**-4 dis/sec per g U-238. 2370400200012 2. Smooth mass yield from these data and data of other 2370400200013 experiments ( see 5 REL-REFs). 2370400200014 REL-REF (R,13058001,H.R.Heydegger+,J,JIN,12,12,1959) 2370400200015 (R,13223001,M.P.Menon+,J,JIN,26,401,1964) 2370400200016 (R,,M.Attrep,T,ATTREP,1965) Univ.Arkanzas, PhD disser. 2370400200017 Three refs. for data used for smooth mass yield. 2370400200018 (R,13063001,M.N.Rao+,J,PR,147,884,1966) 2370400200019 (R,14581001,G.W.Wetherill,J,PR,92,907,1953) 2370400200020 (R,13483001,B.G.Young+,J,CJP,38,1,1960) 2370400200021 (R,13472001,F.T.Ashizawa+,J,JIN,5,12,1957) 2370400200022 (R,23559001,H.Menke+,J,RCA,6,76,1966) 2370400200023 5 refs. for data used for smooth mass yield and for 2370400200024 comparison in Table 2 2370400200025 ADD-RES Independent fission yields calculated by Pappas' method2370400200026 using smooth mass yields are on Fig.2 (table). 2370400200027 STATUS (TABLE) Table 2 of Radiochimica Acta,v.8,p.12,1967 2370400200028 ENDBIB 26 0 2370400200029 NOCOMMON 0 0 2370400200030 DATA 3 6 2370400200031 MASS DATA 1DATA 2 2370400200032 NO-DIM PC/FIS PC/FIS 2370400200033 131. 0.6 0.4 2370400200034 132. 2.32 2.0 2370400200035 133. 4.21 3.2 2370400200036 134. 4.94 4.2 2370400200037 135. 5.39 5.1 2370400200038 136. 5.93 5.8 2370400200039 ENDDATA 8 0 2370400200040 ENDSUBENT 39 0 2370400299999 ENDENTRY 2 0 2370499999999