Water content potential measurement procedure

There are several potential sources of error in these methods. The filters routinely used have a relatively high and somewhat variable sulfate content, so that, at concentrations lower than 10 Mg/m and sampling periods less than 24 h, the reliability of tlie sulfate measurement is reduc. Several different types of filtering media adsorb sulfur dioxide during the ftrst few hours of sampling this alters the amount of sulfate observed. This interference can become critical when sampling periods are less than 24 h and the concentration ratio of sulfur dioxide to sulfate is greater than 5 1. Interference can also be introduced by hot-water extraction when reduced sulfur compounds like sulfite are present, because they are oxidized to sulfates in this process. Another possible error source is that some of the various analytic procedures us for sulfate determination may be influenced by other substances also present in the particulate matter. 

Procedure Transfer 1.00 g of sample into a 150-mL glass beaker, add 10 mL of water, and, while stirring continuously, slowly add 20 mL of 1 A hydrochloric acid to dissolve the sample. Boil rapidly for 1 min, then transfer into a 250-mL plastic beaker, and cool rapidly in ice water. Add 15 mL of 1 M sodium citrate and 10 mL of 0.2 M disodium EDTA, and mix. Adjust the pH to 5.5 0.1 with 1 A hydrochloric acid or 1 A sodium hydroxide, if necessary transfer into a 100-mL volumetric flask dilute to volume with water and mix. Transfer a 50-mL portion of this solution into a 125-mL plastic beaker, and measure the potential of the solution with the apparatus described under Calibration Curve. Determine the fluoride content, in micrograms, of the sample from the Calibration Curve. 

As discussed in para. 418.1, care should be taken relative to the authorized quantity, type and form of the contents of each package because of the potential impact on criticality safety. Any inspections or tests of the contents that may be needed to confirm the characteristics of contents prior to shipment should be specified in the certificate. Measurements that satisfy the requirements of para. 674(b) may need to be performed prior to loading and/or shipment if the package contains irradiated nuclear fuel. The criteria that the measurement must satisfy should be specified or referenced in the certificate for the package (see related advisory material of para. 502.8). Similarly, if special features are allowed to exclude water in-leakage, specific inspections and/or test procedures to ensure compliance should be stated (or referenced) in the certificate. 

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