The transport of close-in fallout plutonium in the Northwest Pacific Ocean : Tracing the water mass movement using 240 Pu/ 239 Pu atom ratio Sang-Han Lee 1, *, Gi-Hoon Hong 2 , Moon-Sik Suk 2 , Janine Gastaud 3 , Jerome La Rosa 4 , Chul-Soo Kim 5 , Eric Wyse 6 , Pavel P. Povinec 7 1 Korea Research Institute of Standards and Science, Daejeon 305-600, Rep. of Korea, 2 Korea Ocean Research and Development Institute, Seoul 425-600, Rep. of Korea, 3 International Atomic Energy Agency, Marine Environment Laboratory, Monaco 4 National Institute of Standards and Technology, Ionizing Radiation Division, Gaithersburg, Maryland, USA 5 International Atomic Energy Agency, Agency’s Laboratories (Seibersdorf), Austria. 6 New Brunswick Laboratory Argonne, Illinois, USA 7 Comenius University, Faculty of Mathematics and Physics, Bratislava, Slovakia 2011. 03. 29
Nuc uclear w lear wea eapons pons Cos Cosmic mic tes testing ting ray ays 14 14 C, , 3 H 7 Be, Be, 10 10 Be,. Be,... Continen Co inental l origin igin 90 Sr Sr, , 137 137 Cs, Cs, 239 240 Pu, Pu, 241 241 Am Am 90 239,240 (w (wind ind transpo sport) Atmosphe Atmosp here 222 Rn Rn 222 210 210 Pb Pb 210 210 Po Po Pr Prec ecipita ipitation tion 222 Rn Rn 222 226 Ra Ra 226 Seawate Seaw ter 228 Ra Ra 228 228 Th Th 228 Scavenging Sca ing with h 232 Th 232 228 228 Ra Ra 210 210 Pb Pb 210 210 Po Po 7 Be Be, , organic an ic and 39 39,240 240 Pu, Pu, 241 241 Am Am inor inorganic ic Advection Ad ion 238 238 U U 234 234 Th Th particula iculate ma matter 228 Ac Ac 228 and con convection ion (c (comple mplexes s and s sorption) ion) 137 137 Cs, Cs, 99 99 Tc 234 U U 230 230 Th Th 234 and and 129 129 I 235 U U 231 231 Pa Pa 235 228 Th Th 228 Re Re-mine minerali lization ion 224 Ra Ra 220 Rn Rn 226 Ra Ra 222 222 Rn Rn 210 210 Pb Pb 224 220 226 Sedimen Sed imentation ion 220 Rn Rn with wi 220 ma marine sno ine snow 230 Th 226 226 Ra Ra 222 222 Rn Rn 230 232 Th 228 228 Ra Ra 232 Con ontinen tinental tal Partic icle le reactiv ive radionu ionucli lides s Sed Sediment iment She Shelf lf ( ( 7 Be Be, , 10 10 Be Be, , 210 210 Pb, Pb, Th, , Pu, Pu, Am i Am isotop sotopes, s, etc.) .)
Pu isotopes High toxicity and possible radiological effects; 238 Pu (t 1/2 =87.74 yr), 239 Pu (t 1/2 =2.4119 10 4 yr), 240 Pu (t 1/2 =6.563 10 3 yr), 241 Pu (t 1/2 =14.4 yr), 240 Pu Pu/ 239 239 Pu Pu ato tom m ratio tio 240 • Stratospheric fallout ( the early 1950s): > 0.30 • Stratospheric fallout ( the mid-1950s): 0.21-0.26 • Nevada test site : 0.035 • Global fallout : 0.18 Geoc Geoche hemical mical an and oc d ocea eano nograph phic ic tr trac acer ers ‹#›
Seawater and sediment sampling stations from the Northwest Pacific Ocean. SW+SED SW+SED St. St. 1 Sea Seawater+Sed +Sedimen iment SW+S SW+SED ED St. 3 St. SW SW SW SW Sea Seawater St. 9 St. SED SED SED SED St. 8 St. Sed Sedimen iment SW+S SW+SED ED St. St. 6 St. St. 7 SED SED TEQ TEQ6 SW SW SED SED TEQ TEQ12 12 SED SED Kawabe et al., 2003 ‹#›
Seawater and sediment sampling stations from the Northwest Pacific Ocean. Equatorial Counter Current Fig. 1 Seawater and sediment sampling stations from the Northwest Pacific Ocean. ‹#›
Se Seawater and nd sediment t sampling on on boa oard ‹#›
Co-precipitation and sequential separation of plutonium (Am, Th and some U) in the seawater Acidified and Filtered Sea Water (20 - 500 liters) 200 + tracer: 242 Pu + carriers: Sr , Cs (with Cs-134, Sr-85) + KMnO 4 + NaOH to pH = 9 MnO 2 • xH 2 O (Pu) supernatant solution + MnCl 2 precipitate acidification to pH = 2 + AMP supernatant solution AMP (Cs) precipitate + oxalic acid + NaOH to pH = 5 - 6 Ca(Sr)C 2 O 4 precipitate supernatant solution (discard) Pre-co Pr conc ncen entr tration tion steps steps for or 90 90 Sr Sr, , 137 137 Cs s an and Pu d Pu ‹#›
Analysis of plutonium isotopes in the seawater MnO 2 • xH 2 O (Pu) precipitate 20 20 L dissolution in HCl + NH 2 OH • HCl + Fe(III) (50 mg);NaOH to [HCl] < 1M heat: Fe(III) reduces to Fe(II) Pu(IV,V,VI) reduces to Pu(III) + NaNO 2 : Fe(II) oxidizes to Fe(III) Pu(III) oxidizes to Pu(IV) + NH 4 OH to pH 8-9, heat/flocculate + HCl to final pH 6 - 7 supernatant solution, Mn II Fe(OH) 3 Pu(IV) precipitate 10 10 L pH 6 - 7 dissolution in HCl, conversion to nitrate with HNO 3 1M HNO 3 solution Fe(III), Pu MnO nO 2 diss dissolution olution pr proc oced edur ure e for or Pu Pu ‹#›
Analysis of plutonium isotopes in the seawater 1M HNO 3 containing Fe(III) and Pu + hydrazinium, heat: Fe III Fe II Pu(IV,V,VI) Pu(III) + conc HNO 3 4M HNO 3 Fe(II) Fe(III), Pu(III) Pu(IV) + NaNO 2 : Pu(III) Pu(IV) + conc HNO 3 8M HNO 3 2- Pu(IV) Pu(NO 3 ) 6 8M HNO 3 containing Fe(III) and Pu(IV) - ) anion AG 1-X8 (NO 3 exchange resin column 8M HNO 3 0.1M NH 4 I-9M 10M HCl HCl Am fraction Th fraction Pu fraction Pu, Pu, Th an h and d Am m sepa separation using tion using an anion ion excha hange ge r resins esins ‹#›
Pu separation and purification or extraction chromatography (TEVA) ‹#›
Pu purification (specially for ICP-MS) Pu solution in 20ml of 1M HNO 3 10mg of Nd 3+ 0.1 g of Mohr’s salt (NH 4 ) 2 Fe 2+ (SO 4 ) 2 .6H 2 O Pu* Pu (III) 0.5ml of 25% NaNO 2 Pu(III) Pu(IV), U UO 2 2+ 5ml of 38-40% of HF Centrifuge 15mim. at 3000rpm Solution: 1 st NdF 3 (Pu 4+ ) 2+ , HF, Fe 3+ , NO 2 - UO 2 Dissolve NdF 3 in 5ml of (4MHNO 3 + 50mg H 3 BO 3 ) + 15ml of 0.1M HNO 3 2 nd Purification using the same NdF 3 procedure 2 nd NdF 3 (Pu 4+ ) Solution: 2+ , HF, Fe 3+ , NO 2 - UO 2 Dissolve NdF 3 in 5ml of (4MHNO 3 + 10mg of H 3 BO 3 ) + 5ml of 2M HNO 3 TEVA column 20ml of 3M HNO 3 20ml of 10M HCl 0.1M HF-0.1M HNO 3 Plutonium ‹#›
239+240 Pu (mBq/L) 239+240 Pu (mBq/L) 0 0.02 0.04 0.06 0.08 0.1 0 0.02 0.04 0.06 0.08 0.1 0 0 500 1000 1000 Povinec, et al., 2003 (Deep Sea Research II) 1500 2000 GEOSECS (1973) 2000 Depth (m) Depth (m) GX-223 GX-224 3000 GX-225 2500 GX-226 Knorr73 (1978) KH-80-2 (1980) St. 6 KH-80-2 (1980) St. 7 3000 4000 CY-11 St. 8 IAEA 97 (1997) IAEA 97 (1997) IAEA 97 (1997) 3500 Stn-1 IAEA 97 (1997) Stn-3 Stn-6 5000 *DUMMY GEOSECS:GX-229 4000 GEOSECS:GX-223-226 Knorr73:St.6+7+8 KH-80-2:CY-11 IAEA 97:Stn-6 IAEA97:Stn 1+3 4500 6000 239+240 Pu (mBq/L) 239+240 Pu (mBq/L) 0 0.02 0.04 0.06 0.08 0.1 0 0.02 0.04 0.06 0.08 0.1 0 0 1000 1000 GEOSECS (1973) GX-229 2000 Knorr73 (1978) 2000 Knorr73 (1978) St. 2 St. 3 Depth (m) St. 4 Depth (m) St. 6 3000 3000 St. 7 St. 8 St. 13 GEOSECS (1973) St. 14 Lee, et al., 2005 (Marine Geology) GX-229 KH-82-1 (1982) 4000 KH-82-1 (1982) 4000 Knorr73 (1978) CE-8 Knorr73 (1978) IAEA 97 (1997) St. 2 IAEA 97 (1997) St. 3 Stn-6 5000 GEOSECS:GX-229 St. 4 5000 GEOSECS:GX-229 GEOSECS:GX-229 Knorr73:St.2+3+4 GEOSECS:GX-229 Knorr73:St.6+7+8+13+14 Knorr73:St.2+3+4 KH-82-1:CE-8 6000 IAEA 97:Stn-6 6000 ‹#›
Nor Northw thwest est Pacific acific Ocea Ocean Northeast Atlantic Ocean (Lee et al., 2009) ‹#›
Dee Deep-wate ter r cir circu cula lation tion a at l t low w la latitud titudes es in in the w th e west ester ern Nor n North th P Pac acifi ific c (Kaw (Kawabe et al. l., , 2003 2003) St. St. 1 St. St. 3 St. 9 St. St. 8 St. St. 7 St. St. 6 St. TEQ6 TEQ Lower Lo er TEQ12 TEQ 12 Cir ircu cumpo mpolar lar Water ter (LCPW) (L PW) ‹#›
Ver ertica tical l pr profile ofile of of 240 240 Pu/ Pu/ 239 239 Pu Pu ato tom East ast Sea ea/ S / Sea ea of of Japa pan (Kim (Ki m et al. al., , 2004 2004) ‹#›
Evaluation of the relative contribution from the global fallout and the close-in fallout Pu ( Global ) ( R R ) ( 1 3 . 60 R ) 2 1 , Pu ( Local ) ( R R ) ( 1 3 . 60 R ) 1 2 From simple mixing model of Krey et al. (1976). where R = 0.20-0.28 ( 240 Pu/ 239 Pu atom ratios of the mixture for the water column), R 1 = 0.18 ( 240 Pu/ 239 Pu atom ratio of global fallout), R 2 = 0.36 ( 240 Pu/ 239 Pu atom ratio of local fallout). R 1 (Pu (Pu ac activ tivity ity %) %) G + + R 2 (Pu (Pu ac activ tivity ity %) %) C = = 100 100% ‹#›
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