N.S. Savannah: Bridging the gap between decommissioning and historic preservation

A first: N.S. Savannah is the world’s first nuclear-­powered merchant ship, and its history is featured in September’s Nuclear News (p. 72). Conceived of and constructed during the Eisenhower administration as a signature element of the Atoms for Peace program, Savannah remains a powerful symbol of this nation’s commitment to advance the peaceful uses of nuclear technology. After successfully completing its programmatic goals and objectives, N.S. Savannah was removed from service in 1970. At a time when decommissioning was a barely fleshed-out concept, Savannah underwent the minimum steps necessary to defuel the reactor, render the nuclear power plant inoperable, and place it into mothballed protective storage. The Nuclear Regulatory Commission issued a possession-only license to MARAD in 1976. In 1980 Congress authorized MARAD to lease Savannah to the state of South Carolina for use as a museum, which continued until 1994. Returned to MARAD custody for dry-docking, the ship was then placed in the agency’s James River Reserve Fleet in Virginia for continued protective storage. The only consideration given to decommissioning then was the expectation that the staff who placed the ship there would be retired when it came back out. We were wrong.

N.S. Savannah undergoing hull cleaning and restoration in 1994 in a floating dry dock at Sparrows Point Extension Yard of the Bethlehem Steel Corporation Shipyard. (Photo: U.S. Department of Defense)

Although Savannah was designated an NHL in 1991, by 1994 the ship was no longer in any sort of condition that could be described as museum-like. Hurricane Hugo in 1989, plus years of resource shortfalls, left the ship’s interior in poor condition. This would not improve over time, despite sealing the ship and placing its interior under dehumidification. Water found its way inside, and with it came mold, mildew, and the occasional pigeon. When decommissioning (the NRC’s DECON status) suddenly became a possibility after the events of September 11, 2001, MARAD found itself in a quandary—what to do with the ship, both for decommissioning and afterward.

Principles: Ultimately the latter would inform and influence the former. By early 2003 MARAD had an answer: It set the rather aspirational and ambitious goal to preserve the ship. This was predicated on the reasonably good structural condition of the hull and superstructure—restoration of the interior was not yet in the cards. This goal had some obvious flowdowns, foremost of which was that Savannah would not be a “rip-and-ship” decommissioning. With that in mind, MARAD adopted four guiding principles to ensure that decommissioning activities met the NHPA’s requirement to minimize harm to the landmark, while meeting the NRC license termination criteria. The principles are as follows:

• Wherever possible, decommissioning activities are undertaken in a manner that fosters historic preservation.
• Dismantlement activities will use existing ship accesses to minimize impacts to adjacent structure.
• Whenever an option is presented or evaluated, the path that promotes preservation is given preferential consideration.
• Opportunities to improve the ship concurrent with decommissioning are exercised.

These principles are preservation-minded, and in practice they resulted in significant improvements to the ship that will benefit its future users. But they were not developed in a vacuum. By the time these principles were adopted in 2005, an overarching strategic concept had been formulated—one that recognized the absence of any commercial nuclear/maritime infrastructure in the country and left Savannah orphaned as the only mobile, waterborne, commercially licensed nuclear power facility in the United States.

MARAD: If decommissioning had been pursued soon after the defueling, it would have been performed at the MARAD servicing facility at the Todd Shipyard in Galveston, Texas. But by 1975, that facility had been removed from service (Savannah’s spent fuel was shipped to the Atomic Energy Commission’s Savannah River Site in 1972). Thirty years later, there was no comparable facility anywhere. Yes, we worked with the U.S. Navy, but no, that wasn’t a viable option for the work at hand.

MARAD opted to follow the commercial decommissioning model where contractors mobilize to the site and use the site’s land to support their activities. Savannah’s licensed site is defined by and limited to the ship itself. So, it became necessary to use the ship’s internal volume to support decommissioning activities, including waste material handling and packaging. This approach was formalized in 2008 with an environmental assessment (EA); thereafter, the principles came into play to guide modifications to the ship. Off-site infrastructure became limited to a pier of sufficient capacity to support cranes and provide space for waste transport trucks, and parking for workers. Most importantly, this off-site infrastructure did not have to be a shipyard, which simplified the administrative and regulatory environment. In essence, we were able to make Savannah decommissioning as close to a landside nuclear power plant project as possible, short of dragging the ship onto land.

The planning was well advanced by the fall of 2006 when a series of unfortunate events, principally budgetary, suspended DECON activities. By then, MARAD was seeking a site for decommissioning and would have chosen Wilmington, N.C., which was the only location actively seeking the project. Savannah was removed from the reserve fleet in August 2006 and towed to Colonna’s Shipyard in Norfolk, Va., for exterior repairs and interior remediation to make the ship fit for occupancy. And yes, the staff who had worked the ship in 1994 were there again in 2006 to bring it out.

SAFSTOR: Over the course of 2007, MARAD wrestled with next steps. With DECON suspended and the ship out of the fleet, it was not so simple to just return it. The regulatory environment had changed dramatically between 1976 and 2007, so MARAD decided if the ship would be returned to protective storage, it would need to be updated to meet the current rules. After dry-docking for maintenance and repairs, Savannah was towed to Baltimore, Md., to carry out a technical and administrative upgrading program to meet contemporary criteria for the NRC’s SAFSTOR designation. The plan was that once complete in 2011, the ship would return to the reserve fleet for about 15 years, before DECON would resume to meet the 2031 license termination deadline (the 1971 defueling was retroactively declared to be the permanent cessation of operations, triggering the 60-year timeline to complete decommissioning).

Of course, as all good plans go, this one fell flat, and Savannah remained in Baltimore without completing the technical upgrades. The administrative upgrades were a complete reconstitution of MARAD’s fundamental license-basis documents, creation of a procedures program, and two license amendments to overhaul the technical specifications and set the stage for DECON. All of this was complete in 2009. In 2013, new MARAD leadership sought to resurrect DECON. Although successful, this effort took four years to accomplish. The first tranche of decommissioning funds was appropriated in 2017, the second in 2018, with the project officially kicking off on October 1, 2017.

Focus: The intervening years allowed for thoughtful examination and refinement of the 2006 plans. Among other things, we discovered that the Baltimore layberth was perfectly suited for the project’s needs. As a good prospective neighbor, MARAD initiated stakeholder outreach for the planned limited SAFSTOR upgrade before the ship arrived; this outreach expanded to address issues and concerns related to decommissioning, including communicating with the neighboring federal, state, and local agencies and jurisdictions, even though decommissioning was in the cognizance of the NRC. MARAD consulted under the National Environmental Policy Act (NEPA) to develop a supplemental EA for DECON in Baltimore and even reached out to the city to address the community’s designation as a “nuclear-free zone.” All of this was necessary because, unlike its landside brethren, Savannah was an itinerant facility with no long-standing ties to the community chosen for the work. And without advance outreach, it would have been impractical to perform the work anywhere.

A so-called Undertaking under the NHPA has similarities to a so-called Action under NEPA. The Council on Environmental Quality encourages federal agencies to perform NEPA and NHPA consultations together, because of their overlapping similarities. Despite this, MARAD chose to conduct its NHPA Section 106 consultation independently. This was because the NEPA action of DECON could be considered on its own merits without further consideration of the action to dispose of the ship. However, the Undertaking recognizes that DECON inextricably leads to disposition, and that both aspects must be considered in parallel because activities in one influence the other.

Agreement: Discussions began in 2013, laying the groundwork for formal consultation beginning in 2018. After several years and a COVID-induced delay, a programmatic agreement (PA) was executed in March 2023 among MARAD, the NRC, the Maryland State Historic Preservation Officer (SHPO), and the Advisory Council on Historic Preservation. Other concurring parties to the PA include the National Park Service, the American Nuclear Society, the National Museum of Nuclear Science and History, and the Smithsonian Institution among others. An interim agreement developed in 2019 guided the planning and evaluation of ship projects before the PA was executed.

The reactor is removed from Savannah. (Photo: EnergySolutions)

The PA includes stipulations for decommissioning-license termination and ship disposition processes, describes MARAD’s preservation principles, and establishes a peer review group to continue consultation. A core decommissioning consideration is to what extent removal of the nuclear power plant systems, structures, and components (SSCs) adversely affects character-defining features of the landmark. There was early consensus that Savannah is not solely defined by the nuclear power plant, and thus the plant’s removal might diminish, but would not negate, its historic significance. If anything, removal of many of the SSCs would allow for greater interpretation of the ship’s nuclear power plant by affording access to formerly inaccessible spaces. Thus, what could have been challenges became opportunities as MARAD recognized that conforming the NRC decommissioning requirements with the NHPA obligations to minimize harm and foster preservation could go hand in hand.

Safety first: The challenge of minimizing harm led MARAD to make use of existing ship accesses for removal of SSCs. Although the guiding principle suggested no new openings, in practice, two openings were cut—to allow safe access and egress for workers, and to provide material handling pathways. The openings were carefully designed and constructed, and one provides access into the retained containment vessel (CV), while exposing the cross section of the ship’s collision protection and biological shielding systems surrounding the CV—features previously hidden from view. This opening is referred to as the CV portal and has been seen on public tours since 2019.

The ship’s interior volume, consisting of cargo holds, crew staterooms, and storerooms, was adapted and outfitted for waste material storage, handling, and packaging; craft labor support; dosimetry and tool issue; office and administrative spaces; and utilities. Climate control systems were installed, cargo holds were insulated, sanitary facilities were constructed, water storage tanks were installed, a training center was fitted, and fire-rated stair towers were constructed to provide access to cargo hold decks and safe egress to weather. Fire and smoke detection systems were installed, and the ship’s general alarm was expanded. MARAD avoided impacting the character-defining features of the ship while ensuring that new construction used sympathetic architectural details and allowed for future adaptive reuse. All the work was done in consultation with the Maryland SHPO and consulting parties to ensure that it conformed with the NHPA. Cost-benefit calculations supported the modifications to the ship as compared to ground rent and rental costs of office and sanitary trailers.

Public access: Savannah was periodically open to the public before decommissioning. As a tangible demonstration of safety, public access was maintained during decommissioning. Cargo Hold 4 was fitted with windows so visitors could observe waste handling and packaging. Displays around the ship explained the decommissioning process—all to showcase the safety of these activities. These efforts continue the ship’s original mission to promote the peaceful and safe use of nuclear power. Just like passengers and visitors in the 1960s could safely view the nuclear engineers at work, today’s visitors have safely observed the decommissioning efforts.

The greatest challenge was reconciling dismantlement with the desire to retain significant structures and components for future interpretation, while allowing for the possibility that Savannah might not be preserved—that it might be scrapped. This end state is a possibility, if not a desirous one, as is the possibility that the ship might be sunk to create an artificial reef. MARAD must demonstrate that preservation of structures and components can be safely accommodated within all possible end states, which is included in its 2023 license termination plan (LTP) submittal to the NRC. Ultimately, the NRC makes the findings and determinations that support those outcomes.

Savannah’s short operating career and lengthy protective storage period created conditions favorable for component preservation. Noteworthy in this regard is the CV itself. To simplify matters, systems and components in outlying areas of the ship not suitable for self-guided visitation have been removed. Within the CV, most piping, valves, and cabling have been removed. Grating and platforms were retained, and new inclined ladders will be installed in 2025. The secondary sides of both steam generators have been preserved in situ. The primary coolant tubes within the heat exchanger sections were removed. Similarly, the internals of the pressurizer were removed, along with the lower hemisphere and its heater wells. The interior of the shell was decontaminated using laser ablation and grinding to reduce activity below the release limits.

Precision: Perhaps the most significant work undertaken that contributes to preservation and future interpretation was the surgical removal of Savannah’s reactor pressure vessel (RPV) from within the annular neutron shield tank (NST) that surrounded it. Entry to the central void is possible from the accesses created to remove the RPV, so that a cutaway or mock-up can be installed to represent the removed RPV. The outer wall of the NST has been retained. Visitation to these spaces, with extant parts of the former plant, is essentially unprecedented for a pressurized water reactor anywhere in the world. The portal is envisioned as the future access point for tours of the CV and represents a significant example of how future preservation and adaptive reuse were considered when making decommissioning modifications.

The Savannah’s reactor pressure vessel arrives at a licensed low-level radioactive waste disposal facility in Clive, Utah. (Photo: EnergySolutions)

On November 8, 2022, the RPV was removed from the ship by floating crane and, like the rest of the low-level radioactive waste, was shipped to the disposal facility in Clive, Utah. Dismantlement actions were essentially complete by mid-2024, and the last waste will be shipped at the end of October. The project is working through final status surveys, with confirmatory surveys performed in July 2024. The ultimate license termination date is dependent on approval of the LTP, completion of satisfactory surveys, and acceptance of those surveys by the NRC. License termination in late 2025 or early 2026 seems reasonable.

In parallel with decommissioning, MARAD has been conducting outreach and planning an affirmative 2025 effort to seek a preservation outcome for Savannah. MARAD hopes to convey the ship about six months after license termination. Because of improvements made by MARAD, the ship is in turnkey condition, with restored public spaces, new and improved infrastructure, and the preserved signature components of its PWR accessible for interpretation and visitation. It can’t be stated enough: There is no other PWR in the world that can offer this experience.

Historic: MARAD’s journey through decommissioning provides lessons for the future of other historic facilities. The threshold age for historic significance is typically 50 years; that Savannah was designated a landmark in 1991 at the age of 29 attests to the exceptional significance of the ship, with much of that due to Eisenhower’s remarkable vision. Many reactors in the United States have had multiple license renewals that push their age well past 50. It’s not hard to imagine that some may have historic significance—think about Three Mile Island Unit 2, for example. When these plants face decommissioning, we hope that future practitioners can look back to MARAD and the N.S. Savannah’s decommissioning process as a prime example of what can be accomplished when two otherwise contradictory processes are thoughtfully managed and executed in a harmonious manner.

Erhard W. Koehler is a deputy federal presentation officer with the U.S. Department of Transportation’s Maritime Administration and since 2004 has been senior technical advisor of the N.S. Savannah. Anne Jennings is an architectural historian and a cultural resources specialist at Tidewater, Inc.