Tag Archives: Cesium

The spent fuel pool at Fukushima #4

A former DOE assistant secretary for renewable energy, Robert Alvarez, has lately been spreading a lot of fearmongering about the stability of the spent fuel pool in reactor 4 at Fukushima. From the start of the accident a lot of question marks regarding the pool has been floating around, including the statement from the NRC chairman Jaczko that the pool might have run dry. Later is was however shown that the pool was never in any danger, it was never damaged in the earthquake and tsunami and it never ran dry. TEPCO released footage from the pool itself and its clear that it is intact and full of water. Continue reading The spent fuel pool at Fukushima #4

Day 20 after the tsunami

Update 12:00(CET)/10:00(UTC)/19:00(JST)

New JAIF update for today, I will compare it with the NISA update from yesterday.

Reactor 1:
Water level in the core: 1.65 (1.60) meters below the top of fuel assemblies
Flow rate of injected water: 133 liter/minute
Core pressure: 612(592) kPa
Containment pressure: 210(230) kPa
Core temperature(feedwater nozzle): 251.2 (270.1) Celsius
Core temperature(bottom head): 130.2 Celsius
Dose rate within containment: 37.7 Sv/hour

Reactor 2:
Water level in the core: 1.5 (1.5)   meters below the top of fuel assemblies
Flow rate of injected water: 133 liter/minute
Core pressure: unknown
Containment pressure: 110 (100) kPa
Core temperature(feedwater nozzle): 174.3 Celsius
Core temperature(bottom head): Unknown
Dose rate within containment:  39.6 Sv/hour
Spent fuel pool temperature:  48 Celsius

Reactor 3:
Water level in the core: 2.3 (2.25)  meters below the top of fuel assemblies
Flow rate of injected water: 116 liters/minute
Core pressure: 121 (119)  kPa
Containment pressure: 173 (164) kPa
Core temperature(feedwater nozzle): 75.3 Celsius (under review)
Core temperature(bottom head): 116.0 Celsius
Dose rate within containment:  26.8 Sv/hour
Status with the reactors are pretty much unchanged. Work is proceeding with pumping away junk water from turbine halls so one can repair the coolant pumps. Work is slow however due to lack of any place to put the radioactive water.

IAEA released a new estimate on ground fallout yesterday and its not pleasant reading. Here is a quote:

Based on measurements of I-131 and Cs-137 in soil, sampled from 18 to 26 March in 9 municipalities at distances of 25 to 58 km from the Fukushima Nuclear Power Plant, the total deposition of iodine-131 and cesium-137 has been calculated. The results indicate a pronounced spatial variability of the total deposition of iodine-131 and cesium-137. The average total deposition determined at these locations for iodine-131 range from 0.2 to 25 Megabecquerel per square metre and for cesium-137 from 0.02-3.7 Megabecquerel per square metre.

This is Chernobyl level ground deposits of Cs-137 around the plant and indicates one might have to expand the evacuation zone around Fukushima. The basis of the IAEA estimate is from the dust samples published by MEXT.


Bloomberg Fukushima workers face risk of uncontrolled reactions
Reuters Japan under pressure to expand evacuation
Kyodo news Kan to review plan to build more nuclear power plants from scratch

MIT nuclear information hub Plutonium in the environment
Depleted Cranium Great presentation on Fukushima Daiichi
Where are the clouds Ibakari analysis for 21 march
Atomic Insights Detectable radiation versus dangerous radiation

Expressen Vattenbombningarna kan ha skadat reaktorerna
Aftonbladet Nivån av radioaktivt jod når nya toppmätningar
DN Kärnkraftverk kan stängas för gott
SvD USA styrka skickas till Fukushima

Dr Angels Redan 1999 protesterade Greenpeace mot Fukushima
Linn Tummen upp för kärnkraft
Norah4you Dags att tala klarspråk Japan


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