ENTRY 30504 20090312 31373050400000001 SUBENT 30504001 20090312 31373050400100001 BIB 14 45 3050400100002 INSTITUTE (3INDTRM) 3050400100003 REFERENCE (R,BARC-584,1971) Exhaustive report 3050400100004 (J,RCA,19,90,1973) Similar text, 3050400100005 values slightly modified 3050400100006 AUTHOR (H.C.Jain,M.V.Ramaniah) 3050400100007 TITLE Molybdenum-99 fission yield in the thermal neutron- 3050400100008 induced fission of plutonium-239 and uranium-235. 3050400100009 FACILITY (REAC,3INDTRM) CIRUS-reactor 3050400100010 INC-SPECT The Cd-ratio for contribution to fission products or 3050400100011 cobalt activation was greater than 200 3050400100012 SAMPLE Accurately weighed solutions of purified plutonium (an-3050400100013 alyzed for Pu-239 content) and nat. uranium respective-3050400100014 ly were evaporated on superpure Al-foil and wrapped 3050400100015 in another Al-foil. The targets contained about 3050400100016 10 micro-g of Pu-239 or U-235. 3050400100017 METHOD (CHSEP) After irradiation, the targets were dissolved. 3050400100018 A known amount of Mo-carrier was added to an aliquot 3050400100019 of the solution. Mo was then separated, purified and 3050400100020 precipitated as lead-molybdate. After determining the 3050400100021 chemical yield, macro-samples of about 20 mg precipit- 3050400100022 ate weight on standard Al-plates with double-coated 3050400100023 cellulose tape, covered with 3 mg/cm2 thick cellophane 3050400100024 paper, were mounted for beta-counting. 3050400100025 DETECTOR (PROPC). End-window methane gas flow, 4pi-geometry. 3050400100026 (GELI). For purity check and beta-gamma coincidence. 3050400100027 DECAY-DATA (42-MO-99,66.18HR) Determined by following the decay of3050400100028 more than 60 samples. 3050400100029 COMMENT Compiler's comment: From a Cd-ratio=200 for Co-59, the 3050400100030 epithermal index r=0.0022 is derived. In his 1977- 3050400100031 evaluation, NEDO-12154-2, B.F. Rider assumed a neutron 3050400100032 temperature of T=40 deg.C. The values r and t were used3050400100033 for a re-evaluation by M.Lammer (Sympos. on Nucl. Data 3050400100034 in Science and Technology, Paris,1973,vol.1,P.505). 3050400100035 STATUS (TABLE) The data are from Table 1 of 3050400100036 Radiochim.Acta 19,p.90. 3050400100037 (APRVD) Approved by H.C.Jain 79/12/13 3050400100038 ERR-ANALYS The accuracies are estimated as follows: 3050400100039 Number of fissile atoms: 1 percent, 3050400100040 Pu-239 fission cross-section: 0.5 percent, 3050400100041 U-235 fission cross-section: 2 percent 3050400100042 Fission product activities: 2 percent. 3050400100043 HISTORY (19790718C) TL. 3050400100044 (19800117U) ML. Author's comments added. 3050400100045 (20090312A) SD:Updated to new date formats,lower case, 3050400100046 made formal corrections. 3050400100047 ENDBIB 45 0 3050400100048 COMMON 1 3 3050400100049 EN-DUMMY 3050400100050 EV 3050400100051 2.7000E-02 3050400100052 ENDCOMMON 3 0 3050400100053 ENDSUBENT 52 0 3050400199999 SUBENT 30504002 20090312 31373050400200001 BIB 5 17 3050400200002 REACTION (92-U-235(N,F)42-MO-99,CUM,FY,,MXW) Absolute determin. 3050400200003 METHOD The detector-efficiency for Mo-99 beta activity was 3050400200004 determined with the aid of accurately known amounts 3050400200005 of Mo-99/Tc-99-m in radioactive equilibrium. The beta 3050400200006 counting efficiency for Mo-99 and the conv.el.-counting3050400200007 efficiency for Tc-99-m were determined through gamma-to3050400200008 -beta/gamma coinc. ratios, and the Tc-99-m contribution3050400200009 was then subtracted from the total counting rate. 3050400200010 MONITOR ((MONIT1)27-CO-59(N,G)27-CO-60,,SIG,,MXW) 3050400200011 For neutron flux. 3050400200012 ((MONIT2)92-U-235(N,F),,SIG,,MXW) 3050400200013 DECAY-MON (27-CO-60-G,5.28YR) 3050400200014 COMMENT The resulting yield value is the average of 3 single 3050400200015 determinations. 3050400200016 Compiler's comment- If the 2200m/sec cross-section 3050400200017 of U-235 (MONIT2) is corrected for Maxwell distribution3050400200018 + epithermal factor, the Mo-99 yield becomes 6.14%. 3050400200019 ENDBIB 17 0 3050400200020 COMMON 2 3 3050400200021 MONIT1 MONIT2 3050400200022 B B 3050400200023 3.7300E+01 5.8020E+02 3050400200024 ENDCOMMON 3 0 3050400200025 DATA 2 1 3050400200026 DATA DATA-ERR 3050400200027 PC/FIS PC/FIS 3050400200028 6.0200E+00 1.6000E-01 3050400200029 ENDDATA 3 0 3050400200030 ENDSUBENT 29 0 3050400299999 SUBENT 30504003 20090312 31373050400300001 BIB 5 16 3050400300002 REACTION (94-PU-239(N,F)42-MO-99,CUM,FY,,MXW) Absolute determin.3050400300003 METHOD The detector-efficiency for Mo-99 beta activity was 3050400300004 determined with the aid of accurately known amounts 3050400300005 of Mo-99/Tc-99-m in radioactive equilibrium. The beta 3050400300006 counting efficiency for Mo-99 and the conv.el.-counting3050400300007 efficiency for Tc-99-m were determined through gamma-to3050400300008 -beta/gamma coinc. ratios, and the Tc-99-m contribution3050400300009 was then subtracted from the total counting rate. 3050400300010 MONITOR (27-CO-59(N,G)27-CO-60,,SIG,,MXW) For neutron flux 3050400300011 (94-PU-239(N,F),,SIG,,MXW) 3050400300012 DECAY-MON (27-CO-60-G,5.28YR) 3050400300013 COMMENT The resulting yield value is the average of 4 single 3050400300014 determinations. 3050400300015 Compiler's comment- If the 2200m/sec cross-section of 3050400300016 Pu-239 (MONIT2) is corrected for Maxwell distribution 3050400300017 + epithermal factor, the Mo-99 yield becomes 6.22%. 3050400300018 ENDBIB 16 0 3050400300019 COMMON 2 3 3050400300020 MONIT1 MONIT2 3050400300021 B B 3050400300022 3.7300E+01 7.4160E+02 3050400300023 ENDCOMMON 3 0 3050400300024 DATA 2 1 3050400300025 DATA DATA-ERR 3050400300026 PC/FIS PC/FIS 3050400300027 6.6600E+00 7.0000E-02 3050400300028 ENDDATA 3 0 3050400300029 ENDSUBENT 28 0 3050400399999 SUBENT 30504004 20090312 31373050400400001 BIB 5 39 3050400400002 REACTION 1(94-PU-239(N,F)42-MO-99,CUM,FY,,MXW)'R-value method' 3050400400003 2(94-PU-239(N,F)42-MO-99,CUM,FY,,MXW)'Modified compari- 3050400400004 son method'. 3050400400005 METHOD 1(RVAL) Using the following terminology 3050400400006 Y(f,p)=yield of product with mass p, from fissile 3050400400007 with mass f, and 3050400400008 A(f,p)=activity (counts/sec) of product p from 3050400400009 fissile f, 3050400400010 the Mo-99 yield is obtained by the 'R-value' method 3050400400011 through the following formula 3050400400012 Y(239,99)= R * (Y(239,140)/Y(235,140)), with 3050400400013 R= (A(239,99)/(A(239,140))* 3050400400014 (A(235,140)/(A(235,99)) 3050400400015 2Using the same terminology, plus n(f) and sig(f)= 3050400400016 number of atoms and fission cross-section of fissile3050400400017 f respectively, the Mo-99 yield is obtained by the 3050400400018 'Modified comparison' method through the following 3050400400019 formula 3050400400020 Y(239,99)=(A(239,99)/A(235,99))*(n(235)/n(239))3050400400021 *(sig(235)/sig(239)) * Y(235,99) 3050400400022 MONITOR ((MONIT1)92-U-235(N,F)42-MO-99,CUM,FY,,MXW) 3050400400023 1((MONIT2)92-U-235(N,F)56-BA-140,CUM,FY,,MXW) 3050400400024 ((MONIT3)94-PU-239(N,F)56-BA-140,CUM,FY,,MXW) 3050400400025 2((MONIT4)92-U-235(N,F),,SIG,,MXW) 3050400400026 ((MONIT5)94-PU-239(N,F),,SIG,,MXW) 3050400400027 COMMENT 1The resulting yield value is the average of 7 single 3050400400028 determinations. 3050400400029 Author's comments fission cross-sections are not 3050400400030 involved.Values were obtained from the same irradiation3050400400031 as that used for modified comparison method and 3050400400032 absolute method. 3050400400033 2The resulting yield value is the average of 10 single 3050400400034 determinations. 3050400400035 Compiler's comment correcting the 2200m/sec cross- 3050400400036 sections as used by the authors for the Maxwell distri-3050400400037 bution + estimated epithermal factor, the Mo-99 yield 3050400400038 from the 'modified comparison' method becomes 6.25%. 3050400400039 HISTORY (20090507A) OS. Added METHOD code, rearranged 3050400400040 MONITOR coding 3050400400041 ENDBIB 39 0 3050400400042 COMMON 5 3 3050400400043 MONIT1 MONIT2 1MONIT3 1MONIT4 2MONIT5 2 3050400400044 PC/FIS PC/FIS PC/FIS B B 3050400400045 6.1600E+00 6.3000E+00 5.6000E+00 5.8020E+02 7.4160E+02 3050400400046 ENDCOMMON 3 0 3050400400047 DATA 4 1 3050400400048 DATA 1DATA-ERR 1DATA 2DATA-ERR 2 3050400400049 PC/FIS PC/FIS PC/FIS PC/FIS 3050400400050 6.8700E+00 1.9000E-01 6.8200E+00 1.5000E-01 3050400400051 ENDDATA 3 0 3050400400052 ENDSUBENT 51 0 3050400499999 ENDENTRY 4 0 3050499999999