Direct Determination of Ultra-trace Plutonium Nanoparticles in Downstream of a Six-Stage HEPA Filter by Inductively-Coupled-Plasma Mass Spectrometry: A Field Application

Figures & data

FIG. 1 Schematic of plutonium aerosol filtration, monitoring, and sampling system.

FIG. 2 Schematic of direct introduction and rapid determination of plutonium aerosol with ²⁴²Pu aerosol addition calibration method by ICP-MS.

TABLE 1 Detector arrangement of Nu MC-ICP-MS for gas direct introduction and solution nebulization

	H7 ∼ H1, Ax, L1	IC0	IC1, IC2	IC3	L2
Gas sample direct introduction	∼	242	∼	239	∼
Uranium solution nebulization	∼	238	∼	235	∼

TABLE 2 Comparison of ²³⁹Pu concentration in four aerosol samples determined by ELEMENT and Nu

	ELEMENT ICP-MS		Nu MC-ICP-MS
No.	Qs (ml/min)	Cs (Bq/m^3)	Qs (ml/min)	Cs (Bq/m^3)
S0	7.6	Not detected	24.5	5.7 × 10^−3
	5.3	1.7 × 10^−2	8.2	1.1 × 10^−2
S1	7.6	2.4 × 10^−2	11.7	2.7 × 10^−2
	Mean	2.0 × 10^−2	Mean	1.9 × 10^−2
	5.6	2.4 × 10^−2	4.9	1.4 × 10^−2
S2	7.6	4.4 × 10^−2	9.6	2.6 × 10^−2
	Mean	3.4 × 10^−2	Mean	2.0 × 10^−2
	5.3	2.1 × 10^−2	7.4	9.3 × 10^−3
S3	7.4	2.9 × 10^−2	10.0	1.6 × 10^−2
	Mean	2.5 × 10^−2	Mean	1.3 × 10^−2

TABLE 3 Estimated sizes of the penetrated plutonium nanoparticles based on single particle detection method

Qs (ml/min)	R 9/2,0		t (s)	N239,p (atom)	D p (m)
5.6	1.26 × 10^−3	1.96 × 10^−3	1	2.14 × 10^3	5.4 × 10^−9
7.6	1.26 × 10^−3	2.96 × 10^−3	1	5.37 × 10^3	7.4 × 10^−9