Steam Generator Channelhead Decontamination

Hennigan Engineering Co., Inc. and Westinghouse Electric Corporation have developed, qualified, and implemented a 3-Dimensional Vessel Dose Reduction System (VDRS). The VDRS was designed to effectively reduce the levels of smearable contamination and exposure associated with steam generator tube testing and repair work. The process is virtually remote-operated from a central control station which incorporates the system's air and high pressure water controls. The VDRS eliminates the need for man entry on the steam generator platform during decontamination intervals.

The system has been designed to operate as a closed loop decontamination process to provide control of airborne contamination and effluent. Remote shielded waste water filtration can be integrated to provide for a fully closed loop process. A 400 H.P. hydroblast pump provides the pressure and flow requirements to operate the 3-dimensional rotary high pressure nozzles.

The system was designed for rapid setup in order to accommodate critical path schedules. Pre-decon equipment layout can be accomplished within a single shift. System integration with steam generator manways and subsequent positioning adjustments can be achieved within minutes. Multiple channelheads can be decontaminated in parallel.

The dose reduction associated with the system has far surpassed that of all other traditional steam generator channelhead decontamination techniques. Variations of the VDRS can be used for pipe decon, tube decon, RHR channelhead cleaning and related decon activities.