Why Fukushima Is a Greater Disaster than Chernobyl and a Warning Sign for the U.S.

Why Fukushima Is a Greater Disaster than Chernobyl and a Warning Sign for the U.S.

By Robert Alvarez

Institute for Policy Studies

April 20, 2012 ·

http://www.ips-dc.org/blog/radioactive_risks_in_japan_from_spent_nuclear_fuel_storage

 

The radioactive inventory of all the irradiated nuclear

fuel stored in spent fuel pools at Fukushima is far

greater and even more problematic than the molten cores.

 

In the aftermath of the world's worst nuclear power

disaster, the news media is just beginning to grasp that

the dangers to Japan and the rest of the world posed by

the Fukushima-Dai-Ichi site are far from over.   After

repeated warnings by former senior Japanese officials,

nuclear experts, and now a U.S. Senator, it is sinking

in that the irradiated nuclear fuel stored in spent fuel

pools amidst the reactor ruins may have far greater

potential offsite consequences  than the molten cores.

 

After visiting the site recently, Senator Ron Wyden (D-

OR) wrote to Japan's ambassador to the U.S. stating

that, "loss of containment in any of these pools could

result in an even greater release than the initial accident."

 

This is why:

 

      Each pool contains irradiated fuel from several

      years of operation, making for an extremely

      large radioactive inventory without a strong

      containment structure that encloses the  reactor cores;

 

      Several  pools are now completely open to the

      atmosphere because the reactor buildings were

      demolished by explosions; they are about 100

      feet above ground and could possibly topple or

      collapse from structural damage coupled with

      another powerful earthquake;

 

      The loss of water exposing the spent fuel will

      result in overheating can cause melting and

      ignite its zirconium metal cladding - resulting

      in a fire that could deposit large amounts of

      radioactive materials over hundreds of miles.

 

Irradiated nuclear fuel, also called "spent fuel," is

extraordinarily radioactive.  In a matter of seconds, an

unprotected human one foot away from a single freshly

removed spent fuel assembly would receive a lethal dose

of radiation within seconds. As one of the most

dangerous materials in the world, spent reactor fuel

poses significant long-term risks, requiring isolation

in a geological disposal site that can protect the human

environment for tens of thousands of years.

 

It's almost 26 years since the Chernobyl reactor

exploded and caught fire releasing enormous amounts of

radioactive debris. The Chernobyl accident revealed the

folly of not having an extra barrier of thick concrete

and steel surrounding the reactor core that is required

for modern plants in the U.S., Japan and elsewhere. The

Fukushima Dai-Ichi accident revealed the folly of

storing huge amounts of highly radioactive spent fuel in

vulnerable pools, high above the ground.

 

What both accidents have in common is widespread

environmental contamination from cesium-137.  With a

half-life of 30, years, Cs-137 gives off penetrating

radiation, as it decays.  Once in the environment, it

mimics potassium as it accumulates in biota and the

human food chain for many decades.  When it enters the

human body, about 75 percent lodges in muscle tissue,

with perhaps the most important muscle being the heart.

Studies of chronic exposure  to Cs-137 among  the people

living near Chernobyl show an alarming rate of heart

problems, particularly among children.

 

As more information is made available, we now know that

the Fukushima Dai-Ichi site is storing 10,833 spent fuel

assemblies (SNF) containing roughly 327 million curies

of long-lived radioactivity About 132 million curies is

cesium-137 or nearly  85 times the amount estimated to

have been released at Chernobyl.

 

The overall problem we face is that nearly all of the

spent fuel at the Dai-Ichi site is in vulnerable pools

in a high risk/consequence earthquake zone. The urgency

of the situation is underscored by the ongoing seismic

activity around NE Japan in which 13 earthquakes of

magnitude 4.0 - 5.7 have occurred off the NE coast of

Honshu in the last 4 days between 4/14 and 4/17.  This

has been the norm since the first quake and tsunami hit

the site on March 11th of last year. Larger quakes are

expected closer to the power plant.

 

Last week, Tokyo Electric Power Company (TEPCO) revealed

plans to remove 2,274 spent fuel assemblies from the

damaged reactors that will probably take at least a

decade to accomplish. The first priority will be removal

of the contents in Pool No. 4. This pool is structurally

damaged and contains about 10 times more cesium-137 than

released at Chernobyl. Removal of SNF from the No. 4

reactor is optimistically expected to begin at the end

of 2013. A significant amount of construction to remove,

debris and reinforce the structurally-damaged reactor

buildings, especially the fuel- handling areas, will be required.

 

Also, it is not safe to keep 1,882 spent fuel assemblies

containing ~57 million curies of long-lived

radioactivity, including nearly 15 times more cs-137

than released at Chernobyl  in the elevated pools at

reactors 5, 6, and 7, which did not experience melt-

downs and explosions.

 

The main reason why there is so much spent fuel at the

Da-Ichi site, is that it was supposed to be sent to the

Rokkasho reprocessing plant, which has experienced 18

lengthy delays throughout its construction history.

Plutonium and uranium was to be extracted from the spent

fuel there, with the plutonium to be used as fuel at the

Monju fast reactor.

 

After several decades and billions of dollars, the

United States effectively abandoned the "closed" nuclear

fuel cycle 30 years ago for cost and nuclear non-

proliferation reasons. Over the past 60 years, the

history of fast reactors using plutonium is littered

with failures the most recent being the Monju project in

Japan. Monju was cancelled in November of last year,

dealing a fatal blow to the dream of a "closed" nuclear

fuel cycle in Japan.

 

The stark reality, if TEPCO's plan is realized, is that

nearly all of the spent fuel at the Da-Ichi containing

some of the largest concentrations of radioactivity on

the planet will remain indefinitely in vulnerable pools.

TEPCO wants to store the spent fuel from the damaged

reactors in the common pool, and only to resort to dry,

cask storage when the common pool's capacity is

exceeded. At this time, the common pool is at 80 percent

storage capacity and will require removal of  SNF to

make room. TEPCO's plan is to minimize dry cask storage

as much as possible and to rely indefinitely on

vulnerable pool storage.  Senator Wyden finds that

TEPCO's plan for remediation carries extraordinary and

continuing risk. He sensibly recommends that retrieval

of spent fuel in existing on-site spent fuel pools to

safer storage in dry casks should be a priority.

 

Given these circumstances, a key goal for the

stabilization of the Fukushima-Daichi site is to place

all of its spent reactor fuel into dry, hardened storage

casks. This will require about 244 additional casks at a

cost of about $1 million per cask. To accomplish this

goal, an international effort is required - something

that Senator Ron Wyden (D-OR) has called for. As we have

learned, despite the enormous destruction from the

earthquake and tsunami at the Dai-Ich Site, the nine dry

casks and their contents were unscathed.  This is an

important lesson we should not ignore.

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