1st RCM, 2005 Jonah NEUTRON ACTIVATION ANALYSIS WITH THE NIGERIA MNSR (NIRR-1) S.A. Jonah REACTOR FACILITY SECTION CENTRE FOR ENERGY RESEARCH AND TRAINING, AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA

1st RCM, 2005 Jonah OUTLINE OF PRESENTATION INTRODUCTION STATUS OF NIRR-1 FACILITIES FOR NAA PLAN FOR THE CRP PRELIMINARY RESULTS DISCUSSION & RECOMMENDATIONS

1st RCM, 2005 Jonah INTRODUCTION-NIRR-1 Design Parameters No. of fuel rods installed:347 with 3 Al dummies No of extra fuel rods:3 Fuel integrity check:periodic gamma ray spectrometry Clean Cold Core ρ ex :3.77 mk (< 50 cents) Special Feature:SRR (Cd absorber) ρ =-1.2 mk Total U-235:1 kg. Nominal power:31 kW Nominal flux:1.0  cm -2 s -1. UsesNAA, Training/Teaching, Research and limited Isotope Production

1st RCM, 2005 Jonah INTRODUCTION-NIRR-1 Parameters for NAA NIRR-1 is 8th commercial MNSR Criticality Feb. 03, 2004 Licensed June 01, 2004 It is designed specifically for NAA and RI Has 6 irradiation sites connected for NAA Suitable flux for NAA is 7x10 10 – 1x10 12 n/cm 2.s Reactor flux stabilizes 15 min after start-up Radial and axial flux variation around core is  3% Flux variation inside irradition vial is  1% Max. Temp., inner site is 55 °C, thus suitable for liquid & biological samples

1st RCM, 2005 Jonah

1st RCM, 2005 Jonah IRRADIATION FACILITIES Irradiation via 2 Pneumatic Transfer Systems (A & B) A connected to a small inner site (A1)&large outer site (A2) B is connected to 3 small inner sites (B1, B2, B3) and a small outer site (B4) B is for short and medium irrad. With Channel B1 designed for cyclic NAA B can tranfer sample from reactor to det., stripper, Pb box A works in auto/manual for long irradiation with a timer

1st RCM, 2005 Jonah

1st RCM, 2005 Jonah GAMMA-RAY COUNTING FACILITIES GEM Series HPGe Coaxial Detector (GEM-30195), p-type Resolution is MeV, 60 Co, HV = V Pb shield cuts background and suitable for MARINELLI 2 sets of plexi-glass sample holders for samp-source posns. Amp settings adjusted for compatibilty with ‘WINSPAN’ ‘WINSPAN’ performs peak ident., evaluatn; & calc. of conc. Efficiency curves have been determined for the sample holders

1st RCM, 2005 Jonah NEUTRON SPECTRUM PARAMETERS OF SLOWPOKE & MNSR FacilityInner irradiation channelOuter irradiation channel f  T n (°C) fFfF f  Tn,Tn, fFfF MNSR, NIRR-1; Zaria, Nigeria, 90% 235 U MNSR, GHARR-1; Accra, Ghana, 90% 235 U _ _ MNSR, PROTYPE, Beijing, China, 90% 235 U __ __ _ SLOWPOKE- 2, DUSR, Halifax, Canada, 90% 235 U _

1st RCM, 2005 Jonah ROUTINE UTILIZATION PROCEDURES Neutron flux/Irradiation channel ProcedureT irr TdTd TmTm Activation products 1x n/cm 2.s/Outer irradiation channel (B4) S12m2-10m10m 28 Al, 27 Mg, 38 Cl, 49 Ca, 66 Cu, 51 Ti, 52 V, 87m Sr, 37 S, 80 Br S22m3-5h10m 24 Na, 42 K, 165 Dy, 56 Mn, 152m Eu, 64 Cu, 172 Er 5x10 11 n/cm 2.s/Inner irradiation channel (B2) L16h2-3d30m 24 Na, 42 K, 76 As, 68m Zn, 122 Sb, 82 Br, 99 Mo, 140 La, 153 Sm, 198 Au, 187 W, 166 Ho, 239 Np(U), 72 Ga, 177 Lu, 131 Ba, 115 Cd, 175 Yb L26h10-15d60m 46 Sc, 141 Ce, 60 Co, 51 Cr, 134 Cs, 152 Eu, 153 Gd, 177 Lu, 131 Ba, 99 Mo, 147 Nd, 86 Rb, 124 Sb, 75 Se, 182 Ta, 160 Tb, 233 Pa(Th), 169 Yb, 65 Zn, 115m Cd, 59 Fe, 85 Sr, 110m Ag, 187 Hf, 95 Zr, 170 Tm

1st RCM, 2005 Jonah CRP PLAN Improve and validate methods for n- spectrum parameters –Acquisition of codes (MCNP5, SAND) Develop methodologies for accurate measurement of fission neutron  ave –Comparison with data libraries Re-measure constants (  o, I o ) for NAA –As specified by CRP Testing of the k0-IAEA software –Using CRMs

1st RCM, 2005 Jonah PRELIMINARY RESULTS- fission  f by single comparator method Reaction  f (mb) (  f 27 Al(n,p) reaction)  f (mb) (I o 197 Au(n,  ) reaction) CALAMAND (IAEA 1974) JENDL ( Al(n,p) 27 Mg 4.20    Al(n,  ) 24 Na0.924    Ti(n,p) 46 Sc 12.5    Ti(n,p) 47 Sc 16.6    Fe(n,p) 54 Mn 85.5    Ni(n,p) 58 Co    Zn(n,p) 64 Cu 49.7    2.3 -

1st RCM, 2005 Jonah PRELIMINARY RESULTS- Fast neutron flux by threshold reactions Detector foilReaction (mb) Half-lifeE  (keV)  f x10 11 (cm -2.s -1 ) Al-0.1%Au foil; 0.1mm thick, IRRM Al(n,p) 27 Mg m % Al; 0.1 mm thick; GODDFELLOW 27 Al(n,p) 27 Mg m   % Ni foil; 0.1mm thick; GOODFELLOW 58 Ni(n,p) 58m+g Co d  % Ti foil; 0.125mm thick; GOODFELLOW 47 Ti(n,p) 47 Sc d  % Fe foil; 1mm thick; GOODFELLOW 54 Fe(n,p) 54 Mn d  0.14

1st RCM, 2005 Jonah DISCUSSION & RECOMMENDATIONS NIRR-1 is used routinely by relative NAA MNSRs´n-spec parameters are in-consistent Cd-covered method with I o (Au) is ok for fiss.  ave Fast n-spec in MNSR is a pure fission spec The Al-0.1%Au is ok for fast flux monitoring Coordinated n-spec charact.program for MNSR Inter comparison exercises