PCGAP: Users Guide and Algorithm Description

Abstract

PCGAP is a software package, which was written to provide gamma-ray pulse height spectrum analysis on a personal computer platform using the Windows NT operating system. It is a collection of programs, which provide a wide range of operability extending from the single user environment to the general purpose counting room. Included in the package are necessary data structures and libraries used to compute quantitative radionuclide concentrations. PCGAP also contains techniques to decontaminate photopeak interferences; determine activity concentrations for radionuclides independent of their associated spectral photopeak size; and three methods to determine the energy scale of a spectrum.PCGAP performs a non-linear least squares fitting of a Gaussian function to spectral photopeaks. The fitting algorithm can fit up to five concurrent photopeaks using a common spectral background. The package includes a program that will automatically locate spectral photopeaks, fit them to a Gaussian function, identify the radionuclides associated with the found photopeaks, and compute a net activity concentration, and for an 8K spectrum do it in less than 30 seconds on a reasonably configured PC. PCGAP also includes a program which allows the operator to manually (using mouse clicks) identify photopeak locations, fit limits and background positions, initiate a fit to the photopeaks and then display the resulting Gaussian function forms. This interactive display function is particularly useful to resolve or properly fit photopeaks with complex adjacent structure and for photopeaks that are near the limit of detection.iv

The effect of birthrate granularity on the release-to-birth ratio for the AGR-1 in-core experiment

“…The gamma-ray spectrum measurements from the HPGe detectors in each FPMS were used to find the release activities of several different isotopes of krypton and xenon shown in Table 2. The acquired spectra were automatically analyzed using the INL-developed PCGAP gamma-ray spectral analysis code [5,6] and were stored electronically. At the end of each irradiation cycle the FPMS measured activities were corrected to account for decay that occurred during transport from the capsules to the detectors.…”

Fission Product Monitoring of TRISO Coated Fuel for the Advanced Gas Reactor-1 Experiment

“…An example spectrum is presented in Figure 4. Acquired spectra are analyzed automatically using the INL-developed PCGAP gamma-ray spectral analysis code [10,11]. When the online analysis is completed, which requires a few seconds, the control program restarts the data collection phase automatically.…”

Installation and Final Testing of an On-Line, Multi-Spectrometer Fission Product Monitoring System (FPMS) to Support Advanced Gas Reactor (AGR) Fuel Testing and Qualification in the Advanced Test Reactor

“…Acquired spectra are analyzed automatically using the INL-developed PCGAP gamma-ray spectral analysis code [5] [6]. At the completion of the online analysis the control system restarts the data collection phase automatically.…”

“…In the first experiment (AGR-1), the test trains incorporates six (6) individual test capsules. Each capsules contains about 51,000 TRISO (TRIstructural ISOtopic) coated uranium oxicarbide fuel particles supported in a graphite matrix.…”