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NS Savannah - Decommissioning

The United States Maritime Administration (MARAD) owns and maintains the SAVANNAH. From 1962 until 1965, the SAVANNAH was operated in experimental service; from 1965 onwards the nuclear facilities have been licensed (License NS-1, Docket 50-238) and regulated by the Atomic Energy Commission (AEC) and Nuclear Regulatory Commission (NRC).

The reactor plant achieved initial criticality in December 1961 and operated from 1962 to 1970 at an average plant thermal power of 30%, resulting in 2.4 effective full power years of irradiation on the structures inside the containment vessel (CV). On 29 January 1973, the US Atomic Energy Commission issued Amendment 13 to the Technical Specifications associated with NSS license NS-1. This amendment acknowledged that the NSS's reactor was no longer operational. This decision was based on the fact that all nuclear fuel had been removed from the ship, and the reactor and associated systems had undergone certain modifications to ensure that they were no longer operable.

As part of the NS Savannah program, two spare reactor cores were manufactured for refuelings that never occurred. After the ship's decommissioning, those spare cores -- each containing 32 fuel assemblies -- were made available to DOE and NRC facilities for research and development purposes. Each of the assemblies, by the way, was made up of 117 stainless steel fuel rods containing uranium oxide pellets. Sandia's Richard Yoshimura (6341) requested ten assemblies be provided to the Labs for fuel transportation studies. One of the assemblies was used for an impact test and was then returned to the Manzano storage area along with the other nine assemblies. And there they sat at Manzano for a couple of decades.

By the mid-1990s the Cold War was over and the DOE weapons complex was looking at ways to divest itself of nuclear materials. In an inventory of materials, the Savannah stuff loomed pretty large. At Sandia, John Sichler (2105), who was then Sandia's Site Nuclear Materials Representative, in early 1996 began looking for viable ways to get the Savannah fuel out of Sandia's hands. A number of options were considered and rejected before a solution was found. In an October 1997 deal, DOE/Albuquerque and the Tennessee Valley Authority agreed that the fuel would be sent to Framatome-Cogema Fuels (FCF) in Lynchburg for refabrication and ultimate use in one of TVA's nuclear power plants.

The present "possession-only" license was first issued by the NRC in 1976; the current amendment (12) was issued in 1994. Decommissioning planning was resumed by MARAD in early 2002, and has been the subject of several previous contracts. A detailed characterization survey and subsequent classification analysis of the Reactor Pressure Vessel (RPV) was conducted in 2005. A reference library is provided in MARAD's Virtual Office of Acquisition; this library includes documents and reports produced during previous contracts; documents and reports pertaining to ongoing licensing activities; MARAD's current license and technical specifications; and other documents either referenced directly herein, or related to this acquisition.

In the late 1990's, MARAD began assessing and evaluating possible course of action for radiological decommissioning. Although the SAVANNAH reactor has been defueled and partially decommissioned, most of the nuclear primary system, including most major primary system components and piping systems, remain within the reactor compartment and in certain adjacent areas of the ship. These components are irradiated to varying degrees, and include small quantities of radioactive material (principally retained primary system water, and plated out corrosion products). The ship's design and construction features provide inherent safeguards to protect these systems and materials, however, in the post 9-11 environment, MARAD made assessments of the physical vulnerability of the ship to terrorist activities, and concluded that the safest course of action to improve the physical security of the ship, and/or to reduce the environmental threat that a terrorist action poses (i.e. a radiological release to the James River and Newport News area) is total decommissioning of the reactor - this eliminates the radiological threat and the attractiveness of the NSS as a vulnerable nuclear target.

The primary system was initially thought to be drained of water, though it was estimated that approximately 1100 gallons of water remained in the lower plenum of the reactor vessel below the inlet nozzles. This estimation was performed by the contractor who was responsible for dewatering the primary system in 1976. During the opening of both port and starboard steam generator primary system inlets, water was observed in both steam generators.

In 2005 MARAD began the process of decommissioning N/S SAVANNAH's nuclear reactor. In 2006, MARAD proposes to relocate the N/S SAVANNAH to Charleston, South Carolina, closer to where the reactor decommissioning project will occur.

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Page last modified: 22-07-2011 17:41:17 ZULU