This paper describes a custom cathodic protection (CP) database, and discusses how this combination of data structure and software improves the ability to analyze cathodic protection. This may be a unique solution to the task of managing CP data, and may have value to others. This paper is primarily about the database design, and not about cathodic protection, per se.
Every database project is a balancing act. A developer can create custom software that performs complex operations requiring modest operator skills. On the other hand, custom software is expensive to both create and maintain. The Hanford CP data system will be used primarily by one person, the CP Engineer. It was concluded that this position could be trained to use off-the-shelf, general purpose database to store data, and spreadsheet software to perform analyses. The database product allows flexibility in data reporting, and enforces referential integrity. The spreadsheet allows many display options. Especially useful are the graphics. This solution entailed minimal computer coding and may lend itself to adoption by others.
The data structure was designed by a database application developer, with close guidance from the CP engineer. The system will require modest amounts of attention from computer support staff, primarily for new query development. The data structures are provided in this report, and are available electronically.
Lockheed Martin Hanford Company (LMHC) manages cathodic protection systems spreading across miles of the Hanford Site, on the dry side of Washington state. Thirty-six (36) rectifiers supply current into 48 anode loops, which in turn serve over 1500 buried anodes. Data are taken at the 36 rectifiers and 563 test stations on a regular basis. One of the responsibilities of the CP Engineer is following rectifier output trends (voltage and current). Another is determining which rectifiers may be contributing to high or low voltage readings at a given test point. Some anode loops have overlapping affects on one another, so the association is not always obvious. Data must be stored in such a way that these interrelationships can be studied effectively.
LMHC met these challenges by developing a unique solution to manage these data. This application stores a wide range of information about the cathodic protection system and its performance. System requirements have been set, the data structure created, and existing data entered.
The Hanford cathodic protection system (see typical CP arrangement, Figure 1) is composed primarily of: rectifiers, anode loops, anodes, protected structures, test points, reference electrodes, and test stations. Baseline measurements of voltage and current were recorded and are referred to as "Acceptance Test Procedure" or ATP data. Rectifier performance measurements are made bi-monthly and on an as-needed basis. Test points are surveyed annually and on an as-needed basis. These measurements are all stored in the database, where they can be used for creating reports and plots.
DISCUSSION
Process Figure 2 describes the work processes that use the CP database. The circles are the processes, and the rectangles are participants in those processes.
