Adapting Online Fiber Optic Colorimeter Systems for Process Measurements in H Canyon

A filter-based photometric analyzer, commonly referred to as a colorimeter, is an important instrument for monitoring uranium concentrations for nuclear safety control in SRS's H-Canyon facility. These instruments are effective but technologically out of date, and the facility does not have spare instruments on hand. Newly developed spectrophotometers will replace them and be capable of more accurate and reliable performance than the current colorimeters. However, the installation of the spectrophotometers will take some time. To make sure that the H-Canyon facility can continue processing operations and reduce the risk of a colorimeter going out of service, spare colorimeters previously configured for Pu monitoring in HB-Line will be reconfigured and calibrated for uranium. These spare colorimeters are readily available and their operating procedures are already known to the H-Canyon facility. This reconfiguration is an efficient and cost-effective means to meet a facility need. Both instruments have a linear response and accurately measure U over the range of concentrations expected in the H Canyon process. The instruments are functionally identical and can be used interchangeably. Changes of acidity within the expected process range will not introduce a bias in the measurement. Higher acidity solutions result in a positive bias, but this is conservative with respect to maintaining nuclear safety