A new method based on dispersive microsolid phase extraction using graphene oxide (GO) as a solid adsorbent and total reflection X‐ray fluorescence (TXRF) spectrometry is proposed for trace determination of uranium. In the developed methodology, a suspension of GO was injected into uranium‐spiked multielement solutions including rubidium; after filtration, the membrane filter with collected GO was placed in a small volume of internal standard acid solution and the eluent containing uranium was deposited onto a fluorine resin‐coated slide glass, which is a disposable sample stage. Using GO was effective for removal of rubidium from the measurement solution to avoid interference between Rb Kα peak and U Lα peak. The high enrichment factor of 150 enables obtaining uranium detection limits of 0.042, 0.087, and 0.12 μg L−1 for ionic strength of 0.01, 0.1, and 1 mol L−1, respectively. Such low detection limits were obtained by using a benchtop TXRF spectrometer with 5‐min measurement. The proposed method is suitable for trace uranium determination in water, including high salinity samples.

As a country's law stipulates the effluent standard uranium concentration in drainage water, the uranium concentration must be determined when drainage water is released from a uranium handling facility, such as the Fukushima Daiichi nuclear power plant. The maximum allowable limit for uranium release at each facility is defined taking into consideration the situation of the facility, such as 1/10 to 1/100 of this effluent standard value. Currently, the uranium concentration of drainage water is commonly determined by α-particle spectrometry, in which several liters of drainage water must be evaporated, requiring about half of a day followed by 2–3 h of measurements, due to the low specific radioactivity of uranium. This work proposes a new methodology for the rapid and simple measurement of several levels of uranium in drainage water by a total reflection X-ray fluorescence (TXRF) analysis. Using a portable device for TXRF measurements was found to enable measurements with 1/10 the sensitivity of the effluent standard value by 10 times condensation of the uranium-containing sample solution; a benchtop device is useful to measure uranium concentrations <1/100 of the effluent standard value. Therefore, the selective usage of methods by a portable and benchtop devices allows for screening and precise evaluation of uranium concentrations in drainage water.

Personnel working in nuclear fuel handling facilities incur a finite risk of injury and uranium contamination in any resulting wounds. The accidental absorption of uranium from the likes of wounds can lead to a significant degree of internal exposure due to its hazardous nature. Although an appropriate surgical resection of tissue in the contaminated wound is useful for suppressing the additional intake of uranium, the rapid quantification of uranium in the wound is required to avoid unnecessary surgery. For surface contamination, the detection of uranium is usually performed using an α‐particle counting method. However, in the case of wound contamination, most of the α‐particles emitted from the uranium cannot pass through the blood oozing from the wound. Therefore, X‐ray fluorescence (XRF) analysis has been proposed as an alternative means of detecting uranium contamination because X‐rays can pass through several millimeters of blood or soft tissue. In the present study, we developed a new methodology for the rapid detection of uranium in wounds that is based on an XRF analysis of contaminated blood collected on filter paper. With XRF, the detection limit for uranium in blood is 0.45 ppm. This value is lower than those of commercially available α‐survey meters by a factor of ~103. Thus, the proposed method could be adopted for the rapid, on‐site detection of uranium in wounds.

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