Operating in a RADCON Environment
On 11 March 2011, Japan experienced the fifth-largest earthquake in recorded history. The resulting tsunami caused immeasurable damage including crippling cooling systems at the Fukushima Daiichi reactor complex near Sendai, Japan. In efforts to prevent a catastrophic meltdown, reactors were vented to release increasing internal pressure. Several fission products were sent skyward in a radioactive plume carried easterly into the western Pacific. In addition to the airborne threat, water drawn from the ocean to cool the reactors drained back into the ocean carrying a contaminated ocean-plume eastward.
Besides damaging the plants at Fukushima, the tsunami devastated the coast, leaving 4 million Japanese citizens without electricity, 1.5 million without water, and 27,000 missing. In response to the government of Japan’s request for assistance, Japan-based U.S. Navy ships sortied to Honshu’s northeast coast in Operation Tomodachi. En route to the affected area, the USS Essex (LHD-2) damage-control experts reviewed FM 3-11.5, Multiservice Tactics, Techniques, and Procedures for Chemical, Biological, Radiological, and Nuclear Decontamination. Although expeditionary missions are common for the Navy’s amphibious fleet, operating and conducting humanitarian assistance and disaster relief (HA/DR) in a radiologically contaminated (RADCON) environment required adaptability, flexibility, dynamic planning—and writing the book along the way.
The Navy trained and operated in a Cold War environment for decades. Procedures were published and practiced, and protective equipment was set aside for nuclear, biological, and chemical warfare. With the waning threat of global nuclear war, priorities shifted to chemical, biological, and radiological (CBR) warfare, with an addendum as nuclear proliferation expanded—CBR-N. References prescribed how the Essex should avoid and recover from a thermonuclear blast, but not how to sustain operations in a RADCON environment.
With the adapted Cold War checklist complete, new questions arose. What does contamination mean? What level of contamination is hazardous? What happens when that level is reached? Can helicopters fly in a plume? Will aircraft and landing craft bring back high levels of contamination to a “clean” ship? The procedures outlined in the Cold War manuals were proving impractical and insufficient for unfettered support of Operation Tomodachi. With her mission unchanged, Essex leaders no longer questioned if they would do it, but how.
The Greatest Threat
Contamination—not radiation—was the long-term threat to sustained HA/DR operations. Radiation was strongest at the Fukushima plant, and the Essex’s distance from the reactors exponentially minimized exposure to that radiation. But fissionable material did not remain at the plant. To reduce heat-generated pressure from the uncooled reactor vessels, plant workers vented radiological contaminates into the atmosphere, creating airborne plumes. The plumes’ paths followed prevailing winds and weather and tracked toward the Essex. Any shipboard system that could collect or concentrate fissionable products such as air handlers, ventilation filters, gunwales, deck-drains, greases, oils, or low spots in the flight deck quickly became the focus of newly trained radiation-control surveyors. A survey program was quickly developed for aircraft and landing craft making contact with contaminated soil ashore.
Once the threat to sustained HA/DR operations was identified, mitigation methods were codified with three goals:
• Limit ship and crew exposure to contamination.
• Limit contamination to the ship’s exterior.
• Sustain continuous HA/DR operations in support of Operation Tomodachi.
Using emerging Navy guidance and expert assistance from on-board Navy radiation specialists from Norfolk Naval Shipyard, the Essex tightly controlled exposure to radiological hazards through organizational adaptations and alterations to flight-deck and well-deck operating procedures.
Changes to routine duties were implemented to track and monitor contamination levels and to advise the commanding officer and embarked leadership on the operational impacts of survey readings and decontamination efforts.
First, a radiation-control watch was established. Teams worked around the clock, monitoring radio messages and logging dozens of survey forms generated by radiation-survey teams stationed on the flight deck or in the well deck.
Next, the Essex’s damage-control assistant was assigned as decontamination coordinator. Added responsibilities included issuing and controlling Mission-Oriented Protective Posture (MOPP) gear—rubber suits, masks, and gloves—dosimeters, and decontamination supplies to survey and flight-deck-decontamination teams. The coordinator also liaised with all radiological players to ensure surveys and decontaminations were handled efficiently and systematically.
Finally, because of changes and updates from both the Fukushima plants and refined radiation health guidance, radiation-control policies were amended daily. To keep sailors and Marines informed and to emphasize the importance of upholding these policies, a radiation-control liaison officer was assigned to work closely with embarked radiation specialists to develop policies, analyze shipboard impacts, and train a cadre of radiation surveyors.
Damage controlmen were trained as radiation health technicians, performing surveys in addition to assisting in decontaminating gear and aircraft. Aerographer’s mates located and modeled radiation plumes and informed the Essex’s command and embarked leadership. The supply department determined how to handle and store radiological waste. All embarked sailors and Marines were trained on the hazards of radiological contamination and to remain vigilant and patient with amended policies.
On the Flight Deck
During Operation Tomodachi, up to 100 sailors and Marines and more than 25 aircraft operated on the flight deck. Each day, approximately five aircraft and 30 individuals went ashore inside the radiological “warm zone.” Aircraft and personnel routinely returned with a measurable level of radiological contamination. To remain flying and keep contamination from entering the skin of the ship, several modifications to flight-deck operations were required:
• All but one entrance and one exit to the flight deck were secured.
• MOPP overboots were worn on the flight deck. They were issued at the access and collected for decontamination at the exit. If they could be decontaminated below 100 corrected counts per minute (CCPM), they were reissued. Any boots failing decontamination were stored for disposal.
• Radiation specialists conducted surveys of every person entering the skin of the ship. No one was exempt from the survey, which averaged five minutes per person. Any gear found above 100 CCPM was decontaminated prior to return.
• Helicopters were surveyed and decontaminated inside and out.
Although implementing new procedures was challenging, necessity demanded a steep learning curve. New processes quickly became routine to maintain unhindered flight operations.
In the Well Deck
Waterborne operations landed hundreds of Marines to the radiological warm zone. Survey procedures used on the flight deck were adapted and refined for larger scale operations in the ocean environment. One of the challenges to surveying wetted gear is the radiological shielding effect of even a thin film of water.
Landing craft utility (LCU) boats were decontaminated at sea prior to entering the well deck using a saltwater wash-down by trained Marines and embarked radiation specialists. Marine boots were surveyed before disembarking the LCU to eliminate contamination spread. Rucksacks were removed before Marines proceeded to a full-body scan, and contaminated uniforms and gear were tagged for decontamination and/or disposal. Some Marines lost contaminated gear exceeding 100 CCPM, for a total of 150 pounds.
Final Decontamination
After completing 32 days of HA/DR in and out of the warm zone, the final question was how effective containment policies and practices had been. During the four-day transit to Okinawa, surveyors needed to prove the Essex was free from contamination by meeting the following criteria:
• Establish that all internal spaces were free from contamination.
• Establish that all external surfaces were free from contamination.
• Segregate, contain, and store all low-level radioactive waste.
The Essex has more than 1,400 internal spaces. Certifying that each was clean in four days was no small task. Embarked radiation specialists and newly trained surveyors swept areas within the ship, averaging 10 minutes per space and 60 minutes for messing and berthing spaces.
External areas, including the flight deck, well deck, aircraft, and Marine vehicles, were extensively surveyed and results mapped. Any area of elevated contamination was decontaminated and closely monitored. The flight deck and all external surfaces were rinsed with the ship’s countermeasure wash-down system and scrubbed with soap and water. After a thorough and extensive survey was completed and documented for future research, the Essex was certified free and clear.
Personal articles that could not be decontaminated were placed in an airtight container, marked as low-level radioactive waste, and stored by the Essex’s hazardous materials organization for future disposal.
Lack of existing guidance was the major obstacle to sustaining operations in a radiological environment. In that absence, the Essex took charge of educating her sailors and Marines and developed effective policies with the assistance of radiation health experts. While the learning curve was steep, the ship’s sailors and Marines mastered the keys to operating in a radiological environment and sustaining humanitarian assistance and disaster relief operations in support of the people of Japan.
Commander Lowell is a senior officer ship-maintenance-and-repair course instructor at the Surface Warfare Officers School in Newport, Rhode Island. He has commanded three crews in six ships and was temporarily assigned as the Essex’s executive officer.