for over a decade the world's largest nuclear power plant has lain eerily dormant a chain of
mishaps both natural and man-made have delayed its reopening yet many locals are clamoring for
its return so why did kashiwazaki kariwa in japan close in the first place what's keeping it shut
and could a previously undetected fault line under the sea condemn it to being abandoned forever
join us today as we ask why the world's largest nuclear power plant was shot down
kashiwazaki kariwan nuclear power plant straddles two towns in the west of nigata prefecture named
you guessed it kashiwazaki and kariwa it's about 135 miles northwest of tokyo on the sea of japan
coast work on the first reactor began in 1980 and in 1985 the first reactor came online it was
followed by another six reactors the last of which came online in 1997. the plant was and still is
the largest nuclear power generating station in the world by net electrical power rating that
means it's capable of pumping out eight thousand two hundred and twelve megawatts which breaks
down as five chunks of 1100 megawatts from five conventional reactors and 1356mhz from each of
the final two reactors installed which are abwr or advanced boiling water reactors the first such
reactors commercially deployed anywhere on earth in fact in theory at least kashiwazaki kariwa
is the fourth largest electricity generating plant of any kind on earth behind three massive
hydroelectric behemoths via taipo on the brazil paraguay border the famous three gorges dam in
china and the guri dam in venezuela for many years kashiwazaki kariwa dutifully supplied
the local grid with clean nuclear energy with only a few minor mishaps to report a hazy slip
up in the early 2000s led to some of the reactors being temporarily taken offline but authorities
chose not to pursue an investigation and allow the plant's operator tepco the tokyo electric power
company to resolve the matter internally in 2007 the 6.6 magnitude chiwetsu offshore earthquake
forced tepco to take all seven reactors offline a colossal setback necessitating the use of natural
gas plants just to keep power supplied to the grid this natural calamity which had a recorded
epicenter just 12 miles away from kariwa shook the plant beyond expected tolerances set out in
the original design leading to electrical fires and radiation leaks albeit leaks well within safe
tolerances and even though the reactors themselves were left unscathed a 21-month shutdown of the
site ensued kashiwazaki curry was shiny new unit 7 reactor was brought back online first following
earthquake focused upgrades on may 19 2009 followed by older units 1 5 and 6. the remaining
units 2 3 and 4 were still offline when the next natural disaster not only derailed operations
but made grim headlines around the world the march 2011 earthquake and resulting tsunami caused
devastation and meltdown at another japanese coastal nuclear facility fukushima daiichi
as it happens neither the quake nor tsunami directly affected operations at kashiwazaki kariwa
but in the ensuing global climate of fear over the potential fallout from fukushima all seven
reactors were again taken offline so additional safety measures could be implemented these
additional safety measures which set tepco back an estimated 1.3 trillion yen and counting were
designed with the fukushima nightmare scenario in mind at fukushima the textbook response to a
big emergency was for the reactors to immediately shut down with cooling water circulated to keep
the fuel rods stable but the massive unforeseen tsunami interrupted this process inundating the
lower levels of the reactor building with seawater this flooded fukushima's diesel generators so its
cooling systems had no power that's how the reactor melted down spewing radiation into the
local atmosphere worse the overheating fuel rods split the very water molecules in the surrounding
steam creating violent hydrogen explosions and still further damage engineers at kashiwazaki
kariwa sought to avoid that scenario by raising its on-site seawall to 15 meters in height this is
despite evidence that a local tsunami could only ever reach about 6.8 metres above sea level such
conservatism would be repeated across a raft of new safety measures but what if even this gigantic
wall was breached the buildings themselves were expensively barricaded in waterproof covers to
prevent sea water entering the plant buildings even through vents or windows local drainage
systems were expanded and reinforced just to be sure in order to avoid what happened at fukushima
when a japanese self-defense force helicopter was forced into service dumping sea water
on the plant's ravaged reactors a new 20k ton dedicated fire fighting reservoir was constructed
near the kiriwa plant sited at 45 metres above sea level in addition 42 water cannon trucks are
now permanently stationed at kashiwazaki kariwa with an extra fail safe of special steam driven
pumps that could if needed deliver water powered only by vapor from the hot reactors themselves
maintaining power at all costs is critical as the fukushima disaster illustrated so kashiwazaki
kuriwa engineers have also installed four sets of mobile gas fire generators and switchboards
on high ground and a fleet of 20 mobile generator cars as a backup all that plus a new designer
filter vent that prevents 99.9 of all radioactive particles escaping a beefed up emergency workforce
numbering 850 people instead of 324 and regular intense drills so you'd think they're good to
switch on by now right wrong despite the vast sums invested by tepco on site the most optimistic
current estimate has unit 7 coming online in late 22 with the other reactors hopefully following
one by one until they're all online by about the year 2028. why public trust in japan and
around the world was shaken by fukushima nuclear facilities especially plants near fault lines
need to be 100 safe and seen to be 100 safe and despite the vast new sea walls and expensive new
infrastructure installed at kashiwazaki kariwa questions have been raised around issues of trust
in the leadership for instance there was the 2002 scandal involving falsification of crucial data
staff anxious that a forthcoming inspection might cause closure carried out what tepco itself has
since called dishonest acts by manipulating steam isolation valves to mislead auditors into
thinking the leak rate on a valve was lower than in reality it's also come to light that in 1995
a diesel backup generator at unit 3 went down but this was not reported when it should have been an
on-site thermal output reading a critical safety metric was exceeded on five occasions between 1991
and 1998 but workers entered inaccurate figures in the log we apologized from the bottom of our
heart for causing anxiety to the public and local residents grovelled tepco vice
president katsutoshi chikudati at the time worse in january of 2021 it came to light that the site
had inadequate provision of protection against terrorism and inadequate protection in place for
its nuclear materials at multiple locations across the dormant plant from 2018 onward it also emerged
that unauthorized individuals had somehow breached the central control room using an employee id card
in addition an intruder detection system had not been functioning and had remained unreported for
an unspecified period of time these administrative slip-ups are still causing tepco headaches as
are serious concerns from the 2007 earthquake during that quake whose fault line now seems
to run directly under the kashiwazaki kariwa site some 400 drums containing low level nuclear waste
were not over 40 lost their lits tepco was roundly criticized for reporting errors late
and because radiation sensors around the site designed to give locals an early warning of
trouble were offline in the aftermath of 2007 causing confusion and rousing suspicion so you
might think locals would be happy to see the back of the kashiwasaki currywur plant but it's
a bit more complicated than that despite the fact that in a recent referendum locals narrowly by 53
percent defeated plans by tepco to move to mixed oxide fuel broadly speaking people in the area
like the plant it employs 6 300 people and many families depend on it to pay the bills it might be
noisy dangerous infrastructure in their backyard but the government pays handsome subsidies of
over 4.7 billion yen to soften the blow when you factor in taxes the overall local boost to revenue
from the plant is closer to 11 billion yen there's competition for that money too in november of 2020
the mayors of onagawa and ishinomaki in miyake prefecture approved the restart of their local
nuclear power station the first such facility to be reopened since fukushima in the town of
kashiwazaki a dwindling population which shrunk dramatically from 90 000 in 2010 to 81 000 last
year is tired of unemployment and boarded up shops so they recently re-elected mayor sakurai masahiro
who ran on a platform of reopening the plant he won in a landslide so kashiwazaki kariwa
was shut down after damage following a 2007 earthquake then kept closed amid a climate of
fear following the fukushima disaster it's still closed shrouded in awkward questions over the
trustworthiness of its management it remains to be seen where the keen locals and japanese government
scrabbling to meet its own kyoto protocol targets will summon the courage to switch the lights on
again what do you think is nuclear energy worth the risk even in earthquake-prone coastal spots
let us know in the comments and don't forget to subscribe for more power mad tech content