2013/02/06

The Chernobyl Prelude

Wreck of the K-431 Soviet nuclear submarine
that exploded on August 10, 1985
There is something sad but instructive in looking back to the early years of this century to learn which nuclear safety issues were of concern to researchers and policy makers in Japan. Instead of proper planning for earthquakes and tsunamis, or an overhaul of the corrupt Japanese nuclear regulatory system, there were worries over the hazards to Japan of Russia’s operating and decommissioning of Soviet era nuclear submarines in the Russian Far East. There were also studies on how much cesium from Chinese weapons tests was landing on Japanese soil.
Compared to what has befallen the country since 2011, these concerns seem quaint, even enviable. The cesium from Chinese weapons tests was miniscule compared to the levels we have to deal with now. It would be nice if the trace deposits from China were our biggest worry.
The concern over the Soviet submarines was more substantial. The Chazhma Bay (alternatively spelled Chasma) explosion of 1985, near Vladivostok, raised some alarming questions about the hazards posed by the Soviet fleet to Russia and countries nearby – North and South Korea, China, and Japan. Or, actually, it would have raised alarming questions if anyone had known about it.
Japan was so concerned about the danger by the late 1990s that it donated money and technical assistance after the fall of the Soviet Union, yet the 1985 accident remained largely unreported, even after 1993 when the Russian government released previously classified information about it.
In a scientific paper about the accident (Takano et al., 2001) authored by Japanese and Russian researchers, the authors concluded that the impact was mostly local. The paper was concerned with possible future accidents, similar to the actual accident that occurred in 1985, with emphasis on the possible effects on Japan if winds had blown in the opposite direction. It concluded, “… the radioactive material might be transported through the atmosphere to Japan in one to several days and might contaminate a wide area of Japan. However, the radiological dose to the area might not be significant.”
The severity of an accident would depend on whether fuel rods were new or old, and whether the Russian government would know or release information about the nuclear inventory involved in the accident. In the case of the 1985 accident, precise data was hard to determine because of Soviet secrecy. A 2003 paper about the accident (Sivintsev, 2003) asked in its title, “Was the Chazhma Accident a Chernobyl of the Far East?” and responded in the negative:

“It is shown that the emission of long-lived radioecologically significant radionuclides in Chazhma was approximately 0.79 Ci, while in the Chernobyl accident this emission was 90 MCiThese quantitative estimates are used to show that the Chazhma accident is not analogous to the 1986 accident in Chernobyl.”

Nonetheless, the accident was still horrific for those involved. Ten people died instantly in the explosive criticality incident and ensuing steam explosion, and 10 others had acute radiation exposure. In total, 290 cleanup workers had to live with the consequences of their exposure. Chernobyl was too big to be kept a secret, but the Chazhma accident was successfully covered up until 1993. In 1998, 205 responders were finally recognized as atomic veterans - equal to Chernobyl liquidators in rights to compensation. Ironically, their accident was overshadowed by Chernobyl happening only eight months later. The local environment was contaminated, both the surrounding hills and the bay. The remains of the submarine itself are still too hot to handle.
The accident illustrates in typical fashion the most unsettling thing about nuclear accidents. In spite of the utmost attempts to foresee problems and control complex systems, it is impossible to know all the complex ways complex systems can break down. In this case, the refueling operation was being done between the submarine and a ship parked alongside it. There had been some problems with the refueling, and these were tragically compounded by the fact that someone had forgotten to make sure that marine traffic in the area was stopped. A navy boat passed by, causing a large wake that disrupted the fuel transfer at a critical moment.


Chazhma Bay Accident Summary:

·           deaths: 10
·           total radiation released: 259 PBq (Fukushima: 840 PBq)*
·           iodine 131 released: 29 GBq
·           workers exposed to radiation: 290
·           workers who suffered acute radiation sickness: 10
·           sediments of Chazhma Bay are 2,000 times more radioactive than before the accident
·           the K-431 submarine wreck continues to be a source of radiation
·           other submarine wrecks in the bay still emit radiation
·           the Dunai Peninsula is still heavily contaminated
·           runoff from the accident’s disposal site still leaks into the bay
·           saving grace: the fuel rods were new and contained almost no strontium or cesium isotopes

source: IPPNW Poster Exhibition: Hibakusha Worldwide - Chazhma Bay, Russia International Physicians for the Prevention of Nuclear War
*This figure for Fukushima may not be accurate. No definitive methodology or tally for the catastrophe has been agreed upon by the scientific community. One reliable estimate was as study by the Norwegian Institute for Air Research that estimated two of the radionuclide releases as 16,700 PBq of short-lived xenon 133, and 36 PBq of long-lived cesium 137 – 42% of the cesium 137 released from Chernobyl. The total release would include data for many more radionuclides.

Unanswered questions:

The few studies on this accident that exist have nothing to tell about how widely the short-lived radionuclides were dispersed. The world learned about the Chernobyl accident from the staff at a Swedish nuclear reactor. They had picked up radiation outside their workplace and set off alarms when they entered it. The Chazma Bay accident begs the question of whether something similar happened at Japanese nuclear power plants. The paper by Takano et al. lists in the references a person by the name of Y. Murakami, and the reference is described as “Radiation monitoring at three TEPCO nuclear reactors facing the Sea of Japan in August 1985, Private Communication, July (2000).” Takano et al. claim that the wind direction, as usual in summer months, was away from Japan toward Russia, and this private communication confirmed that no spike in radiation levels was observed in August 1985. However, it is odd that an unidentified private communication is the best recorded evidence that these researchers could find. If TEPCO had the records, why could they not be made public?
Reading the paper by Takano et al. after the Fukushima catastrophe, it is easy to smile sardonically. In retrospect, we see that the scientific establishment was worried about Russian submarines when it faced the largest threat from its own nuclear power plants – an infrastructure for which everyone had far too much confidence and complacency. But the lesson for everyone in the world is that the next accident is never like the last accident. We need to expect what we least expect. Even if Japan restarts some of its nuclear power plants, the next major nuclear accident will probably happen somewhere else. I’m starting to wonder if it will be in China, Taiwan or South Korea and the winds will blow the fallout over Japan anyway. Japan seems to be destined in history to play a central role as nuclear victim. The only nuclear bombs used in war were dropped on Hiroshima and Nagasaki, the Castle Bravo tests in the Pacific contaminated the Japanese tuna fleet (and tuna catch), the Chazhma Bay accident may or may not have released a radioactive plume that drifted over Japan, and with Fukushima Daiichi Japan victimized itself.

Sources:

The Bellona Foundation. “What is the Committee for Veterans at Special Risk hiding?” October 29, 2007.
Commander Gregory D. Young, U.S. Navy (Retired) Russian Sub Casualties. Proceedings, April 2005.
IPPNW Poster Exhibition: Hibakusha Worldwide - Chazhma Bay, Russia. International Physicians for the Prevention of Nuclear War.
Hideshi Fujiwara. “Atmospheric Deposition of Radioactive Cesium (137Cs) Associated with Dust Events in East Asia.” Bulletin of the National Institute of  Agro-Environmental Sciences. pp. 85 115. 2010.
Takano, Makoto, Vanya Romanova, Hiromi Yamazawa, Yuri Sivinitsev, Keith Compton, Vladimir Novikov, and Frank Parker. “Reactivity Accident of Nuclear Submarine Near Vladivostok.” Journal of Nuclear Science and Technology 38, no. 2. pp. 143-157. 2001.
Yu. V. Sivintsev. “Was the Chazhma Accident a Chernobyl of the Far East?” Atomic Energy. June 2003, Volume 94, Issue 6, pp 421-427.


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