10-13 chernobyl vs fukashma

Question 1

where and when chernobyl

Answer 1

1986
close to the belarus border in ukraine
not a huge demand for land

Question 2

reactor chernobyl

Answer 2

reactor type wouldn’t be allowed
water to cool and different material to moderate it
control rods come from the bottom
uses uo2 (like everyone)
reaction hot -boils water -steam turns turbines

Question 3

chernobyl graphite in reactor

Answer 3

moderateor blocks
built really fast
block has holes in it on longitudonal axis for fuel and control channels
max temp for graphite is 730oC

Question 4

chernobyl disaster build up

Answer 4

doing test- to see if they can turn it off, need to take the heat out
strict rules so test a nigh
bring power down during day- bring in more water
shift change at 12
more control rods in- absorbs neutrons- power dropped more the expected
before test they removed come control rods to increase the power
connect fourth main cooling pump to left loop of system

Question 5

chernobyl disaster test

Answer 5

not enough control rods- TEST START
brought steam in- more reactions more fission- not enough control rods
power kept increasing- runs away- superheated
pushed emergency button which brought in control rods
control rods didn’t come in all the way as rods bent as so hot
graphite catches fire (first thermal explosion)
then explosion

Question 6

chernobyl Zenon pit

Answer 6

zenon fission product- iodine decays into zenon
normally gets burnt by neutrons
stable zenon
if turn reactor off- no neutrons so zenon levels increase (big neutron absorber)
zenon decreases power-then decays increaseing power

Question 7

chernobyl full core breach

Answer 7

moderators on fire
beam of light- fluorescence of excited oxygen and nitrogen atoms in the air
volatile radioisotopes of caesium and iodine were carried away by plume

Question 8

chernobyl first response

Answer 8

block roads to plant
first responders- no protection
took them ages to enter emergency state
day later still fire- dumbed sand, clay and lead on the core
Pripyat evacuated (115,000 ppl)

Question 9

chernobyl rad spreads across europe

Answer 9

explosion released 190 tones of rad gasses into atmosphere
fire 10 days
Russia kept it quiet

Question 10

people worried about what element

Answer 10

iodine short half life so most worried about it -immediate aftermath
take pill to saturate your thyroid o can’t take in radioactive iodine

Question 11

chernobyl main plume line

Answer 11

travelled far as flat topography
headed towards europe- west
turned forest red

Question 12

chernobyl longer response, clean up

Answer 12

bulldozed lots- red forest bulldozed and put more trees on top
villages bulldozed
not allowed to grown in zone
life stock put down
lots of buried and abandoned things
exclusion zone-2600km^2

Question 13

chernobyl elephants foot

Answer 13

large mass of corium formed during core melt down
flow done into basment
smaple each year

Question 14

chernobyl human error

Answer 14

• Isolation of the emergency core cooling system
• Unsafe amount of control rods withdrawn
• Connection of the four main cooling pumps to the right and left of the system
• Design error in having a graphite tip on the control rods
• young inexperience operators as took longer than expected

Question 15

chernobyl aftermath

Answer 15

soluble products leached into surrounding and soil
corium leaks down the core and melts everything in path

Question 16

chernobyl sarcophagous

Answer 16

enclose core, concrete structure, huge block lifted into place in a month
30yr later concrete cracking

Question 17

chernobyl new safe confinement

Answer 17

hermetically sealed
detectors can get data of radiation levels inside, moderate humidity inside
encasement leads to just enough water for fission to occur again but moderated and dried out
dismantle sarcophagus-cranes in roof

Question 18

chernobyl exclusion tourism

Answer 18

bull pull for economy
Pripyat abandoned
can’t eat of drink in zones
clean everyone on exit

Question 19

chernobyl red forest remediation

Answer 19

wild fire issue, windy and flat
keep dumping sand as keeps blowing away

Question 20

chernobyl radiation mapping

Answer 20

people got a lot of rad dose as they did mapping
hotspots- some from debris being piled up and covered in sand
hasn’t been mapped at ground level so hotspots can be smoothed out and not detected

Question 21

Fukushima set up

Answer 21

6 reactors
boiling water reactor
near the coast-colling ponds
safe as water is moderator as well
1,2,3 producing power at time of accident
1,2 running on UO2
3 running on MOX (PuO2/UO2)
enormous structures
control rods from top

Question 22

Fukushima earthquake

Answer 22

subduction zone, earth shifted by 10cm
2.46pm-school run
mag-9
many shocks
35mins after first quake -Tsunami
19000 dead or missing
seawall next to power plant not high enough

Question 23

Fukushima response after quake

Answer 23

control rods dropped once quake detected
power lines destroyed and all back up power- monitoring equipment needs power (1 out of 24 monitoring working)
reactor still hot but knocked out core colling
emergency cooling water brought in by fire trucks

Question 24

Fukushima loss of coolant incident

Answer 24

no water to cool
clad fuel in zr
Zr reacts with water to create hydrogen when hot
1600oC
hydrogen pressurises inside reactor
BANG

Question 25

Fukushima reactor damage

Answer 25

reactor 4 linked to 3, so explosion in 4 from hydrogen flowing in from 3
reactor 3&1 big explosion
reactor 2- intact, no explosion but hissing out and biggest release of material

Question 26

Fukushima and Chernobyl level

Answer 26

both major accident -7
Fukushima is up there as it was so complicated and multiple reactors involved and over many days

Question 27

Fukushima releases

Answer 27

10% of chernobyl
but mainly nobel gasses I131 and Cs137
hard to know as no monitoring
explosion at different times-different wind directions
original 20km radius exclusion zone had to be expanded to the north do to wind and plume

Question 28

Fukushima doseage

Answer 28

very small dose
nun attributed to rad sickness
2 died as they were underneath reaction as Tusnami hit (draund)

Question 29

Fukushima cost

Answer 29

81000 evacuees still displaced- get 1000 dollars a month in psychological suffering compensation
suicide biggest killer as generational homes taken away -elderly population
rad not main issue the evacuation was

Question 30

Fukushima Remediation

Answer 30

lots of remediation as a lot of money into economy, ppl jobs

Question 31

if you lived in the Fukushima fall out zone your life expectancy would decrease by

Answer 31

2-4 weeks

Question 32

Fukushima and chernobyl primary dose contributor

Answer 32

Cs137
long half life

Question 33

Fukushima provenance

Answer 33

can pin point where the plume came from
ash particles spread as far as Tokyo (2microns)

Question 34

Fukushima particulates

Answer 34

fission products- gaseous high temp
Cs swaps out for other ions and sticks (clay rich soil issue)
type A- <10um (as far as Tokyo)
type B- pumice had high density U in it, vesicle, bits of concrete, uranium that had been exploded into the enviro

Question 35

Fukushima soil

Answer 35

has clay rich soils so Cs sticks more
turned over soil on top so no Cs
Cs is mobile, sicks into the soil and can’t get it out

Question 36

I135
turns into

Answer 36

Xe135

Question 37

problem with detecting U+Th in Unmanned Ariel Vehicles

Answer 37

release beta and alpha -very little gamma
so can’t be detected by drone

Question 38

B.J.Howard 2016 paper

Answer 38

comparison of the remediation in cher and fuk
Cs 134+7 were most important longer term dose
chernobyl had to remediate agriculture a lot as more animals in the area
Fuk had to remediate the paddy fields and remove plants
cher took longer to remediate

Question 39

in both most of the radioactivity released was due to

Answer 39

volatile radionuclides (noble gases, iodine, cesium, tellurium)
Steinhauser et al (2014)

Question 40

Steinhauser et al (2014)
chernobyl released more

Answer 40

refractory elements