Onsite nitrogen testing of main steam relief valves

Set point testing of main steam relief valves is typically performed by service vendors at offsite facilities that can handle contaminated equipment and develop the steam pressures and quantities necessary for this testing. Because of the risk of failures that require testing additional valves, this work sometimes can become a critical path. In order to reduce outage impacts from this testing, Illinois Powder worked with VECTRA Technologies, Inc. (VECTRA, formerly Pacific Nuclear) to develop onsite test capabilities using nitrogen. As a result, all as-found testing was completed with 3 weeks of the outage start (eight valves were tested as a result of a failure in the first sample). However, all testing was completed in the time allotted to ship the valves off and obtain results from the first sample. Additional savings will result from the use of onsite craftsmen to refurbish the valves. This paper presents the results of Illinois Power Company's successful effort to perform onsite nitrogen testing of main steam relief valves. The paper includes discussions of the analytical work necessary to develop the correlations between the use of nitrogen versus steam, the regulatory effort necessary to implement this process, the equipment needed, the economics of onsite testing, and the results from our refueling outage testing during October 1993