epri bwrvip mitigation committee meeting june 15-16, 2016 ... · hitachi-ge nuclear energy, ltd...
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1 Hitachi-GE Nuclear Energy, Ltd Proprietary Information
WPE-OG-0891
Deposited Pt particle analysis result by Pt nano-particle colloid injection
Makoto Nagase Hitachi-GE Nuclear Energy, Ltd.
EPRI BWRVIP Mitigation Committee Meeting June 15-16, 2016, San Antonio, TX, USA
2 Hitachi-GE Nuclear Energy, Ltd Proprietary Information
Hitachi-GE presented the Platinum nano-particle colloid produced by a γ-ray irradiation method at last December meeting as an improved injection chemical for OLNC to mitigate changes in water chemistry during application.
1. Platinum colloid solution was produced from H2Pt(OH)6 suspension (Pt 1g/L) by γ-ray irradiation of 6kGy. 2. Main product was PtO2 with mean particle diameter of 2.3 nm. Products became negatively charged and precipitated below pH 3.52.
3. ECP of 316 SS was reduced by Pt nano-particle colloid injection to a value as low as that by Na2Pt(OH)6 injection in excess H2 condition.
Background: Last presentation summary
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Unanswered questions were as follows. Q: How much is the quantity of Pt deposition? Q: How much is the deposited particle diameter?
Background: Questions at last meeting
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Deposition test conditions: • Pre-oxidized type 316L
(DO; 350ppb, DH; 60ppb, Time; 500h)
• Flow velocity; 0.04cm/s • Deposition time; 72 h
Deposition experiment conditions and result
N2,H2 gases
DO
DH
EC
Water tank
EC <10μS/m DO 350pb DH 60ppb
Demineralizer
Heat ex.
Pump
5L/ｈ
280℃
Zn soln.
Zn 2ppb
Pt 8ppb
Pt soln.
Test section
（316L SS）
Heater
Cooler
Test loop and conditions
Test result: Pt deposition density;
0.39μg/cm2
(H2/H2O2 = 2.7)
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Analysis result of deposited Pt particle
STEM analysis result of test coupon
（Ａ）
（Ｂ） （Ｃ）
STEM: Scanning Transmission Electron Microscope
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Analysis result of deposited Pt particle
STEM analysis result of (A)
（Ａ）
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Analysis result of deposited Pt particle
STEM analysis result of (B)
（Ｂ）
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Analysis result of deposited Pt particle
STEM analysis result of (C)
（Ｃ）
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Analysis result of deposited Pt particle
EDX analysis result of (C)
EDX of Pt at （Ｃ）
EDX: Energy Dispersive X-ray spectrometry
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Pt deposition reduction at injection line
0.00.20.40.60.81.01.21.41.61.8
140 160 180 200 220 240 260Dep
osite
d am
ount
of P
t (m
g/cm
2 )
Temperature (oC)
Platinum colloid solution*1
Na2Pt(OH)6 solution
Pt soln
Pure water
N2+H2
N2
Temp. controller
Pump
Cooler
Regulator
Electric furnace
Test section
0.5ml/min
0.5ml/min
Test tube Pre-oxidized Carbon steel (215 oC, DO 8ppm, 1week) (ID 0.22cm, L10cm)
Temp 150-235 oC DH 160 ppb Pt conc 0.05 wt% for Na2Pt(OH)6 soln.
0.04 wt% for Platinum colloid soln.
*1: Deposited amount was multiplied by 1.25 because Pt concentration was different .
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Summary
1. Platinum deposition density was about 0.4 μg/cm2 after 72 hours injection with Pt concentration of 8 ppb and Zn concentration of 2 ppb.
2. Most of deposited Pt particle diameter was less than 10 nm.
Deposited Pt particle amount and its diameter by Pt nano-particle colloid injection were analyzed.
Pt nano-particle colloid has a potential to mitigate plugging of Pt injection line. Laboratory test result showed that Pt deposition rate was about 1/5 of that with a conventional chemical.