By Chie Sano and Junko Akiyama
The recent invasion of Ukraine has caused us to consider the possible catastrophic outcomes, especially in awareness of the Chernobyl nuclear power plant. While nuclear power plants should not be attacked, even in times of war, it is wise to have emergency plans in place.
The Tokyo National Research Institute of Cultural Properties, Japan has decided to release an English version of the materials previously published in Japanese in 2014 on the Institute’s website: https://www.tobunken.go.jp/info/info220331/index-e.html . This document, titled “Risk Management for Museums: Focusing on Dealing with Cultural Objects Contaminated by Radionuclides”, is a summary of the procedures created to protect and treat cultural heritage and technicians against radioactive materials in museums, based on direct experience from the major accident on March 11, 2011 when a tsunami, following an earthquake in the Tohoku region, caused the release of harmful radioactive substances into the atmosphere at the Fukushima Daiichi Nuclear Power Plant (International Nuclear Event Scale [INES] level 7).
At that time three researchers with national qualifications as radiation specialists were working at the Institute. However, two months passed before the museum staff asked questions, because they did not known that there were experts with national qualification as radiation specialists in our Institute. During that time, museum workers were in a state of anxiety, trying to respond quickly to urgent concerns, such as prohibiting the transfer of cultural property from overseas to Japan and returning any cultural property lent to Japan safely back home overseas. The first question asked was how the radiation would affect paintings—whether or not cultural property contaminated with radioactive materials could be exhibited and how to decontaminate objects exposed to radiation. It seemed that the crisis was worsened by our neglect to disseminate the information we had gathered on the pollution and its impact on cultural property. In July we held a meeting with museum staff and began to discuss what kind of problems were occurring due to the radiation as well as addressing what the museums wanted to know and how best to cooperate in this situation. In the end, those attending included institutes, national museums, museum associations in Japan, museums in Fukushima, the Cultural Property Department in Fukushima Prefecture, and the Agency for Cultural Affairs. Experts in radiation chemistry and radiochemistry also attended the meeting in order to better understand the conditions particular to cultural property and to dispel the concerns of those involved in the care of cultural property regarding the measures needed to improve the contamination situation.
The “Risk Management” document summarizes the emergency response protocol at the beginning of a nuclear accident, including an explanation of radioactive substances, radiation measurement methods, protective materials, decontamination of cultural properties, and domestic regulations which are summarized as an appendix. In the document, only countermeasures against radioactive iodine and radioactive cesium are covered. In a nuclear power plant accident, the damage varies greatly depending on whether or not the plant is operating. In the Fukushima Daiichi Nuclear Power Plant, at the time of the accident, the reactor was urgently shut down due to the earthquake. Then the tsunami rushed in and destroyed the electrical system. As a result, the reactor could not be cooled, and gases (along with other substances with a low boiling temperature which tend to become gas) were released and diffused into the atmosphere. These gasses included radioactive tritium, iodine-131, cesium-134, and cesium-137. The hydrogen explosion damaged the reactors, but the large rubble and the chemicals in a solid state remained on the premises of the nuclear power plant without scattering far.
Radiation was measured all over Japan for a time after the accident, but the radiation itself did not travel far from the place where the accident occurred. Rather, radiation was detected in the dust, contaminated with radioactive substances which were carried into the atmosphere and air currents. Some of the radioactive dust fell to the ground due to gravity (fallout) or by rain (washout), polluting the land. The radioactive cesium was easily absorbed into the clay ground, but fortunately, cesium has a relatively small chemical effect. Burial mounds could not be opened to the public until the radiation dose dropped to safe levels over time. Traditional gardens and buildings were decontaminated as part of house maintenance. The cultural objects inside museums were hardly contaminated except in cases when rain water leaked in through building cracks or glass panes damaged by the earthquake.
This is, of course, not the first time that radioactive substances have been released into the atmosphere from operating power plants. At the time of the Chernobyl accident in Ukraine (also INES level 7) in 1986, I, Sano, was still a college student, observing radioactive material orbiting the earth with a scintillation detector approximately once a week for about three weeks. When the first fallout arrived in Japan, I was instructed to wear disposable rain ponchos, leaving them outside the front door before entering and throwing them away.
This document is most useful when, following a nuclear disaster, the government promptly discloses the status of radioactive contamination and dispatches necessary protective measures and specialized rescue teams. In the case of the 2011 Fukushima accident, information was not disclosed to us in Tokyo, but emergency assistance to radiation-exposed citizens began the next day. Medical teams with expertise in treatment of atomic bomb survivors were dispatched to Fukushima one after another from remote areas such as Hiroshima and Nagasaki, according to the national press release on March 16th. There was a large-scale air leak on March 14, and radiation measurements began to be released in each region on a national scale on March 15.
Russia's invasion of Ukraine at present has made it clear that, along with other emergency protocol during times of war and other crises, it is also necessary to consider risk management for radiation countermeasures. Other important considerations and measures to take as part of an emergency plan are fire prevention, anti-theft protection, measures against mice and insects, mold prevention, and avoiding dust accumulation in daily management, which will make for quicker collection evacuation at any time. It would also be helpful to locate radiation specialists ahead of time including contact information in case there is need of any consultation or measurements. Our hope is that this document will help others to better understand the risks within their collection and museum buildings, to prepare the necessary networks and systems in advance, and to evacuate safely while keeping cultural property safe during an emergency. We sincerely hope that this document will be useful to the conservation community around the world.
Chie Sano graduated in radiochemistry from the graduate school of the University of Tokyo in 1988. Since 1989 she has studied the problem of air pollution in the museum and is currently an honorary researcher of the Tokyo National Research Institute for Cultural Properties. From 2017 to 2020 she was the head of the Center for Conservation Science.
Junko Akiyama graduated in conservation science from the Graduate School of Conservation, Tokyo University of the Arts in 2000. She was involved in managing environmental conservation at the Kyushu National Museum from 2010 to 2020. In 2020 she started researching the preservation of cultural heritage at her current workplace. Since 2014 she has also participated in the Disaster Risk Management Project.
(To access and download the guide "Risk Management for Museums: Focusing on Dealing with Cultural Objects Contaminated by Radioniclides", see the article in the June-July 2022 "News in Conservation" Issue 90, p. 10-14) or visit: https://www.tobunken.go.jp/info/info220331/index-e.html )