Northwest Pacific Ocean : Tracing the water mass movement using 240 - - PowerPoint PPT Presentation

SLIDE 1

• 2011. 03. 29

The transport of close-in fallout plutonium in the Northwest Pacific Ocean : Tracing the water mass movement using 240Pu/239Pu atom ratio

Sang-Han Lee1,*, Gi-Hoon Hong2, Moon-Sik Suk2, Janine Gastaud3, Jerome La Rosa4, Chul-Soo Kim5, Eric Wyse6, Pavel P. Povinec7

1Korea Research Institute of Standards and Science, Daejeon 305-600, Rep. of Korea, 2Korea Ocean Research and Development Institute, Seoul 425-600, Rep. of Korea, 3International Atomic Energy Agency, Marine Environment Laboratory, Monaco 4National Institute of Standards and Technology, Ionizing Radiation Division, Gaithersburg, Maryland, USA 5International Atomic Energy Agency, Agency’s Laboratories (Seibersdorf), Austria. 6 New Brunswick Laboratory Argonne, Illinois, USA 7Comenius University, Faculty of Mathematics and Physics, Bratislava, Slovakia

SLIDE 2

222 222Rn

Rn Cos Cosmic mic ray ays

210

210Pb

Pb

Con

• ntinen

tinental tal She Shelf lf

232 232Th  228 228Ra

Ra

220 220Rn

Rn

222 222Rn

Rn

238 238U

U  234

234Th

Th

234 234U

U  230

230Th

Th

235 235U

U  231

231Pa

Pa

210 210Pb

Pb  210

210Po

Po Sca Scavenging ing with h

• rganic an

ic and inor inorganic ic particula iculate ma matter (c (comple mplexes s and s sorption) ion)

7Be

Be, ,

39 39,240 240Pu,

Pu,241

241Am

Am Re Re-mine minerali lization ion Sed Sedimen imentation ion wi with ma marine sno ine snow   

230 230Th 

226

226Ra

Ra  222

222Rn

Rn

226 226Ra

Ra  222

222Rn

Rn  210

210Pb

Pb 

232 232Th 

228

228Ra

Ra Ad Advection ion and con convection ion

137 137Cs,

Cs, 99

99Tc

and and 129

129I

Seaw Seawate ter Atmosp Atmosphe here

Sed Sediment iment

90 90Sr

Sr, , 137

137Cs,

Cs, 239

239,240 240Pu,

Pu, 241

241Am

Am

7Be,

Be,10

10Be,.

Be,... 14

14C,

, 3H

228 228Ra

Ra  228

228Th

Th

Nuc uclear w lear wea eapons pons tes testing ting

210

210Po

Po Co Continen inental l origin igin (w (wind ind transpo sport)

228 228Th

Th

224 224Ra

Ra

220 220Rn

Rn

228 228Ac

Ac Partic icle le reactiv ive radionu ionucli lides s ( ( 7Be Be, , 10

10Be

Be, , 210

210Pb,

Pb, Th, , Pu, Pu, Am i Am isotop sotopes, s, etc.) .)

226 226Ra

Ra

Pr Prec ecipita ipitation tion

SLIDE 3

‹#›

High toxicity and possible radiological effects; 238Pu (t1/2=87.74 yr), 239Pu (t1/2=2.4119  104 yr), 240Pu (t1/2=6.563  103 yr), 241Pu (t1/2=14.4 yr), Geoc Geoche hemical mical an and oc d ocea eano nograph phic ic tr trac acer ers

• 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

Pu isotopes

240 240Pu

Pu/239

239Pu

Pu ato tom m ratio tio

SLIDE 4

‹#›

Seawater and sediment sampling stations from the Northwest Pacific Ocean.

St.

• St. 1

St.

• St. 3

St.

• St. 9

St.

• St. 8

St.

• St. 7

St.

• St. 6

TEQ TEQ6 TEQ TEQ12 12

Kawabe et al., 2003

SW+SED SW+SED

Sea Seawater+Sed +Sedimen iment SED SED

SW SW

Sea Seawater SW+S SW+SED ED SED SED SW SW SW+S SW+SED ED SW SW SED SED SED SED

SED SED

Sed Sedimen iment

SLIDE 5

‹#›

Seawater and sediment sampling stations from the Northwest Pacific Ocean.

• Fig. 1 Seawater and sediment sampling stations from the

Northwest Pacific Ocean.

Equatorial Counter Current

SLIDE 6

‹#›

Se Seawater and nd sediment t sampling on

• n boa
• ard

SLIDE 7

‹#›

Acidified and Filtered Sea Water (20 - 500 liters) + tracer: 242Pu + carriers: Sr , Cs (with Cs-134, Sr-85) + KMnO4 + NaOH to pH = 9 + MnCl2 supernatant solution MnO2•xH2O (Pu) precipitate acidification to pH = 2 + AMP supernatant solution AMP (Cs) precipitate + oxalic acid + NaOH to pH = 5 - 6 supernatant solution Ca(Sr)C2O4 precipitate (discard)

Pr Pre-co conc ncen entr tration tion steps steps for

• r 90

90Sr

Sr, , 137

137Cs

s an and Pu d Pu

Co-precipitation and sequential separation of plutonium (Am, Th and some U) in the seawater

200

SLIDE 8

‹#›

MnO2•xH2O (Pu) precipitate

dissolution in HCl + NH2OH•HCl + Fe(III) (50 mg);NaOH to [HCl] < 1M heat: Fe(III) reduces to Fe(II) Pu(IV,V,VI) reduces to Pu(III) + NaNO2: Fe(II) oxidizes to Fe(III) Pu(III) oxidizes to Pu(IV) + NH4OH to pH 8-9, heat/flocculate + HCl to final pH 6 - 7

supernatant solution, MnII pH 6 - 7 Fe(OH)3 Pu(IV) precipitate

dissolution in HCl, conversion to nitrate with HNO3

1M HNO3 solution Fe(III), Pu

MnO nO2 diss dissolution

• lution pr

proc

• ced

edur ure e for

• r Pu

Pu

Analysis of plutonium isotopes in the seawater

20 20 L 10 10 L

SLIDE 9

‹#›

1M HNO3 containing Fe(III) and Pu Pu(IV,V,VI) Pu(III) + conc HNO3 4M HNO3 Fe(II) Fe(III), Pu(III) Pu(IV) + NaNO2: Pu(III) Pu(IV) + conc HNO3 8M HNO3 Pu(IV) Pu(NO3)6

2-

8M HNO3 containing Fe(III) and Pu(IV) AG 1-X8 (NO3

• ) anion

exchange resin column Am fraction Th fraction Pu fraction 10M HCl 8M HNO3 0.1M NH4I-9M HCl + hydrazinium, heat: FeIII FeII

Pu, Pu, Th an h and d Am m sepa separation using tion using an anion ion excha hange ge r resins esins

Analysis of plutonium isotopes in the seawater

SLIDE 10

‹#›

• r extraction chromatography (TEVA)

Pu separation and purification

SLIDE 11

‹#›

10mg of Nd3+ 0.1g of Mohr’s salt (NH4)2Fe2+(SO4)2.6H2O Pu*  Pu (III) Pu solution in 20ml of 1M HNO3 0.5ml of 25% NaNO2 Pu(III)  Pu(IV), U  UO2

2+

5ml of 38-40% of HF

1st NdF3(Pu4+)

Pu purification (specially for ICP-MS)

Centrifuge 15mim. at 3000rpm Solution: UO2

2+, HF, Fe3+, NO2

• Dissolve NdF3 in 5ml of (4MHNO3 + 50mg

H3BO3) + 15ml of 0.1M HNO3

2nd NdF3(Pu4+)

Dissolve NdF3 in 5ml of (4MHNO3 + 10mg of H3BO3) + 5ml of 2M HNO3 TEVA column Plutonium 20ml of 3M HNO3 20ml of 10M HCl 0.1M HF-0.1M HNO3 Solution: UO2

2+, HF, Fe3+, NO2

• 2nd Purification using the same NdF3

procedure

SLIDE 12

‹#›

1000 2000 3000 4000 5000 6000 0.02 0.04 0.06 0.08 0.1

239+240Pu (mBq/L)

Depth (m) GEOSECS (1973)

GX-223 GX-224 GX-225 GX-226

KH-80-2 (1980)

KH-80-2 (1980)

CY-11

IAEA 97 (1997)

IAEA 97 (1997)

Stn-1 Stn-3

*DUMMY GEOSECS:GX-223-226 KH-80-2:CY-11 IAEA97:Stn 1+3

500 1000 1500 2000 2500 3000 3500 4000 4500 0.02 0.04 0.06 0.08 0.1

239+240Pu (mBq/L)

Depth (m) Knorr73 (1978)

• St. 6
• St. 7
• St. 8

IAEA 97 (1997)

IAEA 97 (1997)

Stn-6

GEOSECS:GX-229 Knorr73:St.6+7+8 IAEA 97:Stn-6

1000 2000 3000 4000 5000 6000 0.02 0.04 0.06 0.08 0.1

239+240Pu (mBq/L)

Depth (m) GEOSECS (1973)

GX-229

Knorr73 (1978)

Knorr73 (1978)

• St. 2
• St. 3
• St. 4

GEOSECS:GX-229 GEOSECS:GX-229 Knorr73:St.2+3+4

1000 2000 3000 4000 5000 6000 0.02 0.04 0.06 0.08 0.1

239+240Pu (mBq/L)

Depth (m) GEOSECS (1973)

GX-229

Knorr73 (1978)

Knorr73 (1978)

• St. 2
• St. 3
• St. 4
• St. 6
• St. 7
• St. 8
• St. 13
• St. 14

KH-82-1 (1982)

KH-82-1 (1982)

CE-8

IAEA 97 (1997)

IAEA 97 (1997)

Stn-6

GEOSECS:GX-229 GEOSECS:GX-229 Knorr73:St.2+3+4 Knorr73:St.6+7+8+13+14 KH-82-1:CE-8 IAEA 97:Stn-6

Lee, et al., 2005 (Marine Geology) Povinec, et al., 2003 (Deep Sea Research II)

SLIDE 13

‹#›

Northeast Atlantic Ocean (Lee et al., 2009)

Nor Northw thwest est Pacific acific Ocea Ocean

SLIDE 14

‹#›

Dee Deep-wate ter r cir circu cula lation tion a at l t low w la latitud titudes es in in th the w e west ester ern Nor n North th P Pac acifi ific c (Kaw

(Kawabe et al. l., , 2003 2003)

Lo Lower er Cir ircu cumpo mpolar lar Water ter (L (LCPW) PW) St.

• St. 1

St.

• St. 3

St.

• St. 9

St.

• St. 8

St.

• St. 7

St.

• St. 6

TEQ TEQ6 TEQ TEQ12 12

SLIDE 15

‹#›

East ast Sea ea/ S / Sea ea of

• f Japa

pan (Ki (Kim m et al. al., , 2004 2004)

Ver ertica tical l pr profile

• file of
• f 240

240Pu/

Pu/239

239Pu

Pu ato tom

SLIDE 16

‹#›

From simple mixing model of Krey et al. (1976). where R = 0.20-0.28 ( 240Pu/239Pu atom ratios of the mixture for the water column), R1 = 0.18 ( 240Pu/239Pu atom ratio of global fallout), R2 = 0.36 ( 240Pu/239Pu atom ratio of local fallout).

, ) 60 . 3 1 ( ) 60 . 3 1 ( ) ( ) ( ) ( ) (

2 1 1 2

R R R R R R Local Pu Global Pu     

Evaluation of the relative contribution from the global fallout and the close-in fallout

R1(Pu (Pu ac activ tivity ity %) %)G + + R2(Pu (Pu ac activ tivity ity %) %)C= = 100 100%

SLIDE 17

‹#›

Pacific Seawater (profile)

240Pu

/239Pu Plutonium (%)

240Pu

/239Pu Plutonium (%) Station 1 atoms ratio Rg Rc Rg (global fallout) Rc(close

• in fallout)
• St. 7

Atom ratio R (global fallout) R (close

• in fallout)

0.224 0.18 0.36 69 31 0.226 0.18 0.36 67 33 100 0.212 0.18 0.36 77 23 250 0.230 0.18 0.36 65 35 250 0.223 0.18 0.36 69 31 500 0.206 0.18 0.36 81 19 500 0.233 0.18 0.36 63 37 750 0.218 0.18 0.36 73 27 700 0.234 0.18 0.36 63 37 1000 0.235 0.18 0.36 62 38 1000 0.236 0.18 0.36 61 39 2000 0.228 0.18 0.36 67 33 1500 0.238 0.18 0.36 60 40 3100 0.263 0.18 0.36 45 55 2500 0.242 0.18 0.36 58 42 3600 0.281 0.18 0.36 36 64 3500 0.243 0.18 0.36 57 43 0.236 0.18 0.36 61 39 4500 0.250 0.18 0.36 53 47 5800 0.262 0.18 0.36 46 54 0.236 0.18 0.36 61 39

• St. 3
• St. 8

0.206 0.18 0.36 81 19 0.219 0.18 0.36 72 28 200 0.213 0.18 0.36 76 24 300 0.218 0.18 0.36 73 27 450 0.234 0.18 0.36 62 38 600 0.211 0.18 0.36 77 23 600 0.245 0.18 0.36 56 44 900 0.207 0.18 0.36 80 20 800 0.237 0.18 0.36 60 40 900 0.210 0.18 0.36 78 22 1100 0.230 0.18 0.36 65 35 1200 0.221 0.18 0.36 71 29 2000 0.248 0.18 0.36 54 46 2000 0.221 0.18 0.36 71 29 4000 0.261 0.18 0.36 47 53 4900 0.251 0.18 0.36 53 47 5000 0.258 0.18 0.36 48 52 5400 0.278 0.18 0.36 37 63 5400 0.232 0.18 0.36 64 36 0.226 0.18 0.36 67 33 0.236 0.18 0.36 61 39

mea mean mea mean mea mean mea mean

SLIDE 18

‹#› (0.15-0.21)

(Kim et al., 2003) (Wang and Yamada., 2010)

240Pu/239Pu atom ratios in the bottom sediments of the

NW Pacific Ocean

SLIDE 19

‹#›

Latitude(oN) 5 10 15 20 25 30 35 40 240Pu/239Pu atom ratio 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32

Northwest Pacific

(St. 1 & St. 9)

East Mariana Basin

(St. 6 & St. 8)

West Caroline Basin

(St. TEQ 6 & TEQ 12)

The atom ratios of 240Pu/239Pu with latitude in the surface sediment

Global fallout (0.18)

SLIDE 20

‹#›

Equatorial Counter Current: St. TEQ 12 (flowing East) North Equatorial Current: St. TEQ 6 (flowing West)

West Caroline Basin

SLIDE 21

‹#›

Equatorial Counter Current: St. TEQ 12 (flowing East) North Equatorial Current: St. TEQ 6 (flowing West) TEQ cruise (Korean TOGA program) at 137oE Line West Caroline Basin

SLIDE 22

‹#›

N. . Equ Equatorial ial Cu Current Equ Equatorial ial Co Counter Cu Current

SLIDE 23

‹#›

N. . Equ Equatorial ial Cu Current Equ Equatorial ial Co Counter Cu Current Kuroshio shio Cu Current

LCP CPW (Lo Lower Cir er Circumpolar cumpolar Water) ter)

SLIDE 24

‹#›

• The atom ratios of 240Pu/239Pu in the seawater samples were increasing with depth

and were higher than the global fallout ratio (0.18).

• The elevated 240Pu/239Pu atom ratios indicate that the close-in fallout plutonium

isotopes originating from the Pacific Proving Grounds (PPGs) due to the U.S. tests are prevailing in the seawater in the NW Pacific Ocean.

• While the atom ratio of 240Pu/239Pu in the surface sediment collected near the PPGs

(at St. 6, 7, 8, TEQ 6) was significantly higher than the global fallout ratio, St. 1 and TEQ 12 presented the global fallout. As a consequence, the water masses associated with the currents would play a key role in driving the distribution of Pu and in transporting Pu from the PPGs to the far eastern marginal sea in the NW Pacific Ocean.

Conclusion

SLIDE 25

Thank you for your attention!