Abstract: Failed fuel cladding in light water reactors can lead to premature reactor shutdown for removal of the failed fuel bundles from the core. The lost power and associated fuel replacement costs are astronomically high, approaching a million dollars per day in near term costs. Additionally, the long term affect on an operating plant are the release and distribution around the plant of long-lived fission products which increase radiation levels and impose increased radiological protection procedures. A method has been developed which allows for on-line early detection of failed fuel elements while the plant is operating through flowing off-gas through a conduit to a gamma spectrograph with a time delay to allow interfering short lived isotopes to decay and then analyzing for gamma radiation from at least one of the nuclides Kr-85m, Kr-87, Kr-88, Xe-133, Xe-135, Xe-135m and Xe-138.

Abstract: A filter element adapter assembly is set forth for attaching a linearly extending filter element having a wall structure formed of a filtering material and having first and second end closures, the second end closure having a passageway therethrough and defining a filter element fitting to an attachment structure. The assembly comprises first and second tubular adapters and an insert seal formulated of a material which is softer than the adapters. Large screw threads are provided on the seal and on the portions of the adapters which screw onto the seal. The adapters abut a flange on the seal to provide a leak free arrangement.

Abstract: The buildup of radioactive contaminants on the inside surface of light water reactor water systems is retarded by the use of a chromium coating of at least five hundred Angstroms on the surface exposed to the water system. The chromium coating is then passivated by exposure to an oxygen source for about five hours at a temperature between 150.degree. C. and 450.degree. C.

Abstract: A method and apparatus are set forth for calibration of a flowmeter in a system having a condensible fluid flowing in it. A known volume of a liquid test solution is inserted into the system flowpath upstream of the flowmeter with the solution having dissolved in it a known concentration of an inert gas. The indicated flowrate is observed on the flowmeter. The concentration of the inert gas present in the condensed fluid downstream of the flowmeter is measured. This allows a determination of the true flowrate which corresponds to the flowrate indicated by the flowmeter. The method and apparatus of the invention are particularly useful wherein the system is a heat transfer system of a power plant.

Abstract: A method is set forth of passivating at least a portion of a surface of a stainless steel member to retard buildup of radioactive materials on such surface portion. The surface portion is preferably polished until it is substantially featureless at 100 times magnification. The polished surface is exposed to a gaseous oxygen source at a temperature of 150.degree. C. to 450.degree. C. for at least about five hours. When a pipe passivated as set forth above is utilized in a water system of a light water nuclear reactor, radioactive buildup on the surface is significantly reduced as compared to pipes which have been passivated by exposure to liquid during the passivating process.