USS Pandemonium

USS Pandemonium

USS Pandemonium (PCDC-1) in 1957.
History
United States
Name	USS Pandemonium
Owner	Naval Station Treasure Island
Operator	United States Navy
Ordered	November 1955
Builder	Biological and Chemical Warfare Defense School Treasure Island
Christened	1 February 1957
Out of service	1992
Identification	Hull number PCDC-1
Fate	Demolished 1996
General characteristics
Length	173 ft (53 m)
Beam	24 ft (7.3 m)
Propulsion	None

USS Pandemonium (hull number PCDC-1) was a mockup of a ship built by the United States Navy at Naval Station Treasure Island on Treasure Island, San Francisco for the purpose of training personnel in atomic-biological-chemical warfare, specifically for training in nuclear fallout decontamination and radiation monitoring procedures. It was described by the Navy as "one of the most realistic training aids" for atomic-biological-chemical warfare.

Construction

Plan view of the USS Pandemonium showing the eleven cesium source locations.

The USS Pandemonium was built as a full-scale mockup of a PC-461-class submarine chaser. It was assembled by the Biological and Chemical Warfare Defense School of Naval Station Treasure Island using refurbished parts and scrap from multiple ships. The construction was based on plans for the USS Kelso (originally USS PC-1170), supplemented by photographs of PC-461-class submarine chasers. It was built on a large concrete slab in a 400-by-600-foot (120 by 180 m) gravel-covered lot on the northwestern section of Treasure Island (now called Site I). Eleven tubes were installed at various locations in the mockup for the purpose of holding cesium-137 sources.

The name Pandemonium was chosen as it described the state of its decks after a simulated enemy attack.

Activities

Site I

Aerial photograph of the Pandemonium at Site I (1969).

Initially, training aboard the Pandemonium only consisted of radiation monitoring. The 'ship' had eleven locations where sealed cesium-137 radiation sources could be raised out of lead shielded tubes by an instructor, and each cesium source had a radioactivity content of 0.65 Curies. The radiation from the sources were intended to accurately model the radiation exposure that sailors would experience after a ship was covered in fallout from a thermonuclear bomb detonation. Trainees would practice locating those sources using radiac detectors.

By the time personnel were being trained for the Operation Hardtack I and Hardtack II series of nuclear tests of 1958, a second system had been installed to spray large surfaces of the Pandemonium with short-lived radioactive isotopes; this would more accurately simulate radioactive fallout than individual cesium sources. For this purpose, the Atomic Energy Commission authorized the use of bromine-80, bromine-82, sodium-24, and potassium-42. A water tank was built near the Pandemonium to hold a solution of bromine-82, a radioactive isotope with a half-life of approximately 35 hours (the other permitted isotopes were not used on the Pandemonium). The 'ship' was doused with this solution using the spray system, then trainees would scrub it clean. Initially the only measure taken to prevent the discharge of contaminated radioactive water created by this process directly into San Francisco Bay was to block the in-ground inlets to old stormwater sewers that ran under Site I; the contaminated water was allowed to seep into the gravel bed of the site. By the end of 1963, the Navy had built two storage tanks to collect the contaminated water and allow sufficient time for the radioactive materials to decay to safe levels before discharging the water into the bay.

Training courses using the USS Pandemonium each took six weeks. During that time, participants were exposed to up to 300 millirem of radiation per week.

Site II

USS Pandemonium at Site II (1970).

From May 1969 to September 1970, the USS Pandemonium was dismantled, moved, and reassembled at the northeastern corner of Treasure Island (now called Site II), adjacent to what is now the island’s sewage treatment plant. It was refurbished to be part of the Damage Control School Treasure Island, and was co-located with the Damage Control School's tear gas training building. The area of Site I was demolished and several buildings containing housing units for members of the military with families were constructed on the site.

Decontamination and radiation monitoring training continued at Site II until at least 1979, by which time the use of bromine-82 training for fallout decontamination had long since ceased (in mid-1972) and all but one cesium source had been removed from the 'ship'. Use of the Pandemonium ended in 1992 when it was placed in permanent layup in anticipation of the 1993 Base Realignment and Closure of Naval Station Treasure Island. In 1996, the USS Pandemonium was disassembled, removed from Treasure Island, and sold for scrap, leaving only the concrete foundation and holding tanks.

Environmental impact

Site I and Site II are radiologically and chemically contaminated, and the US Navy has been criticized for its ongoing remediation and decontamination efforts on Treasure Island. Local reporters stated that the Navy contractor dumped the remains of the Pandemonium in an undisclosed landfill, then released the site without performing necessary radiation surveys. Despite a reportedly inadequate release of the island, the 2006 radiological assessment of Treasure Island determined that Site I and Site II were not radiologically impacted. This was criticized as a "radiological lie", and multiple discoveries of radioactive material in "clean" areas occurred from 2006 to 2011. These incidents, along with reports from California State health officials, prompted a second radiological assessment in 2014. The 2014 radiological assessment determined that both Site I and Site II are radiologically impacted based on suspected contamination resulting from unlicensed radioactivity survey instruments containing check sources made with radium-226 and failure to comply with procedures regarding leak checking of licensed check sources.

In addition to the radioactive contamination, chemical contamination is present at both sites. At Site I (now a residential area with low-income housing), the soil was found to contain PAH and PCB contamination at 19,000 ppm, exceeding the legal maximum of 0.22 ppm. Contaminants in the area of Site I, including lead, arsenic, and DDT, have been identified in the soil as recently as 2023. The soil around Site II was completely removed in 2009 to a depth of 12 feet (4 m) to remove 790 tons of soil contaminated with PCBs, dioxins, heavy metals, pesticides, and petroleum products. The soil removal was not directly related to the training activities aboard the Pandemonium, but the vessel and surrounding area had been used to store PCB-laden transformers and PCB spills had been reported. This soil removal had the effect of destroying the concrete foundation of the 'ship', leaving only the bromine-water holding tanks.