Kerncentrales Japan #27

quote:

Op donderdag 28 april 2011 07:53 schreef macca728 het volgende:

[..]

haha een zeer veilige en schone energiebron, een energiebron die voor de twee grootste milieurampen uit de geschiedenis hebben gezorgd en wereldwijd miljoenen mensen en dieren heeft vernietigd of gaat vernietigen in de komende honderden jaren.

quote:

Op donderdag 28 april 2011 08:10 schreef RemcoDelft het volgende:

[..]

Feiten zeggen je niet zo veel he...
Kolen zorgen jaarlijks voor een miljoen doden. Weet je het verschil tussen kolen en uranium?

quote:

Op dinsdag 26 april 2011 19:00 schreef rubbereend het volgende:
Van de twitter:

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en

[..]

quote:

Op woensdag 27 april 2011 15:58 schreef macca728 het volgende:

[..]

Precies, ze zouden Japan moeten dwingen de schade te betalen. Potje breken potje betalen.

quote:

Gissen naar aantal doden Tsjernobyl

Toegevoegd: dinsdag 26 apr 2011, 09:51
Update: dinsdag 26 apr 2011, 09:55

Ook in Nederland moeten mensen zijn overleden door de kernramp in Tsjernobyl, vandaag 25 jaar geleden.

Het RIVM komt tot deze conclusie, zonder daar harde cijfers over te hebben.

Zelfs is niet bekend hoeveel slachtoffers er in de directe omgeving van de Oekraïnse centrale waren. Van maar ongeveer vijftig mensen staat vast dat ze door de ramp zijn gestorven.

Dat zijn in elk geval twee mensen die in de centrale zelf de explosie niet hebben overleefd, zegt Ronald Smetsers, hoofd stralingsonderzoek van het RIVM.
Schildklierkanker

Een grote groep mensen in de buurt van de rampplek heeft blootgestaan aan een hoog stralingsniveau. Die hebben er een 'accuut stralingssyndroom' aan overgehouden.

"Uit die groep zijn 28 mensen binnen enkele maanden overleden. In de jaren daarna zijn er uit die groep nog 19 mensen gestorven, maar niemand weet helemaal zeker of er toch geen andere oorzaken waren."

Na het ongeluk kregen 6000 kinderen in de buurt van Tsjernobyl schildklierkanker door radioactief besmet voedsel, waaronder melk. "Dat is een vervelende vorm van kanker, maar in de meeste gevallen is het gelukkig niet dodelijk. Uit de groep zijn 15 kinderen gestorven."
Grote afstand

Dat zijn bij elkaar enkele tientallen overlijdensgevallen waarvan vrijwel zeker vaststaat dat ze het gevolg waren van het nucleaire ongeluk, maar daar houdt de zekerheid op.

Deskundigen zeggen dat op grote afstand van Tsjernobyl tot in heel Europa en ook jaren na de ramp, nog mensen zijn gestorven door straling uit de Oekraïnse centrale.
Een rapport van de VN kwam vijf jaar geleden op 4000 slachtoffers in de omgeving van Tsjernobyl. "Daarna kwamen er rapporten die zeggen dat in heel Europa 600 miljoen mensen met straling te maken hebben gehad. Dus moeten er veel meer doden zijn."
Nederland

Het stralingsniveau in Nederland was 1/1000 van dat in Tsjernobyl. "Het probleem is dat we de risicofactor kennen bij hoge stralingsniveaus, maar we weten niet of die ook geldt voor een kleine dosis. "

Als je van hetzelfde risico uitgaat, zouden er in Nederland honderd doden zijn als gevolg van de kernramp, zegt Smetsers. "Maar je vindt ze nooit terug en wetenschappelijk bewijs is er niet

quote:

Op donderdag 28 april 2011 12:50 schreef Basp1 het volgende:
Gisteren had de vpro de documantaire tjernobyl 4 ever.

http://www.nederland2.nl/(...)ding/15576?gids=true

Hierin deed iemand de uitspraak dat de levensverwachting in die streken flink gezakt was, hiermee zou toch wel al het een en ander te bewijzen moeten zijn dat dat komt door de centrale. Maar dan komen andere factoren natuurlijk ook nog om de hoek kijken en is het voor de nucliare lobby natuurlijk veel gemakkelijker om te verklaren dat de levensverwachting afgenomen is omdat de levenstandaard in de oekranine gezakt is.

quote:

Op donderdag 28 april 2011 12:58 schreef macca728 het volgende:

[..]

en het gebeurt ook nog in Rusland en Japan, waardoor er ongetwijfeld heel veel in de doofpot wordt gestopt, want kernenergie is voor een hoop mensen net zo winstgevend als de wapenhandel.

Uitgeroeid krijg je het niet meer, dus moeten we maar leven met het feit dat we over een x aantal jaar weer gemiddeld 30 worden.

quote:

Op donderdag 28 april 2011 06:57 schreef Pheno het volgende:

[..]

Zegt diegene die met hippy YT-linkjes aan komt zetten en een stuk Japan wil laten afzinken om alles maar de zee in te dumpen. Inderdaad, die reacties zijn gestoeld op hogere scheikunde!

Geen hond hier weet hoe het zit, en we (en vooral Japan) zal moeten zien hoe dit gaat uitpakken. Onderzoekers hebben nog flink wat te doen nadat de grootste problemen afgelopen zijn.

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Op woensdag 27 april 2011 17:16 schreef RemcoDelft het volgende:

[..]

Dat "enorme" gebieden onleefbaar zijn, is toch niet zo'n probleem? De USSR was gigantisch groot, en zeer dunbevolkt. Waarom zouden er perse op elk plekje mensen moeten wonen?
Wat wij "enorm" noemen, is op de kaart van de USSR trouwens amper zichtbaar...

quote:

Op donderdag 28 april 2011 07:41 schreef RemcoDelft het volgende:
Het gaat om absolute cijfers, niets anders.

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Op vrijdag 29 april 2011 02:27 schreef maartena het volgende:
Overigens maak ik me geen zorgen. Ik woon een half uur van een kerncentrale af met 2 reactoren.... in een aardbevingsgebied. Ik woon ook anderhalf uur vanaf de haven van San Diego, waar met kernreactoren aangedreven vliegdekschepen hun thuishaven hebben, en waar kernonderzeeërs geladen worden met hun 24 MIRV kruisraketten.

(Overigens wel goed beveiligd allemaal, mijn vrouw heeft een tijdje op 1 van de kernonderzeeër-basisen gewerkt, en als de onderzeeërs werden geladen, zat de hele basis op lockdown - niemand mocht dan vertrekken, of zelfs de gebouwen uit waar ze op dat moment waren.)

Ik wil alleen maar aangeven dat je niet omwille van schone energie de gevaren van kernenergie zomaar even overboord moet gooien. Voor dichtbevolkte gebieden is het zeker de moeite waard om te kijken of er betere alternatieven zijn. Nederland zou bijvoorbeeld ook goed energie kunnen opwekken met een getijde-centrale, onderwater. Zolang we een MAAN hebben, en dus eb en vloed, kunnen dergelijke centrales langs de kust ons continue van energie voorzien. En NOG schoner dan kernenergie.

In Nederland kunnen dergelijke centrales bijv. gebouwd worden in Zeeland, bijv. bij de Oosterschelde kering, waar de stroming sterk is. Stel je voor, bij elke schuif een turbine. Dat is een nog beter idee dan kernenergie.

quote:

Een probleem stelt zich, dat de centrale maar om de 12 uur energie levert. De corrosie van zout water drijft de kosten op. De centrales zijn ook niet zo milieuvriendelijk, omdat de levende wezens in zee gewoon zijn om te leven met een normale wissel van eb en vloed, terwijl de centrale dat verstoort door op andere tijden water te lozen of op te houden.

quote:

URGENT: Radiation leaks from fuel rods suspected at Tsuruga plant: local gov't

Leaks of radioactive materials from fuel rods have been suspected at a nuclear power plant in Tsuruga, the Fukui prefectural government said Monday, citing a rise in density of the toxic substances in coolant water.

quote:

Japan Atomic: may shut nuke reactor due to problem, no leak

TOKYO (Reuters) - Electricity wholesaler Japan Atomic Power Co said on Monday it would consider shutting a reactor at its Tsuruga nuclear plant due to a technical problem, adding that there had been no radiation leak from the facility. The plant is around 450 km (280 miles) west of Tokyo in Fukui prefecture, an area that was not affected by a massive earthquake and subsequent tsunami that hit Japan on March 11.

The company said it had identified a possible leak of iodine from the 1,160-megawatt No.2 reactor's nuclear fuel assemblies into its coolant.

quote:

Op vrijdag 29 april 2011 08:10 schreef Pheno het volgende:

[..]

Uit alleen al de wiki:

[..]

Dat geeft dus ook weer problemen, Het eerste natuurlijk de verminderde energie-opbrengst en de kosten om zo'n ding draaiend te houden. Zout is een bitch. En je vermoerd meteen veel visleven daar.

quote:

Op dinsdag 26 april 2011 15:38 schreef phpmystyle het volgende:
Wel jammer dat er door dit hele gebeuren weer heel schamper gedaan wordt over kerncentrales.

quote:

Op maandag 2 mei 2011 12:46 schreef niels0 het volgende:
Juist niet. Ik vind het prima dat het opnieuw op de agenda staat. Het aantal (kleine) incidenten in de zwaardere industrie is de laatste jaren weer stijgende (Ik baseer dit op cijfers van OneGaz, die mag ik helaas niet openbaar maken). Dat betekent dat de aandacht verslapt en sowieso, waar mensen werken worden fouten gemaakt alleen zijn ongelukken (al dan niet door menselijk/technisch falen) bij kerncentrales gelijk zo heftig en onbeheersbaar. daarbij is er nog steeds geen oplossing voor het afval.

quote:

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
UNIT ONE
ASSUMPTIONS: (based on input from multiple data source: JAIF, NISA, TEPCO, & GEH)
Core Status: Core is contained in the reactor pressure vessel, reactor water level is unknown.
The volume of sea water injected to cool the core has left enough salt to fill the
lower plenum to the core plate. (GEH, INPO, Bettis, KAPL).
Vessel temperatures and pressures:
149°C at bottom drain and 197°C at FW nozzle (NISA 1800 JDT 3/25)
RPV at 65.7 psia (increasing trend), DW and torus pressure at 40 psia (decreasing
trend) (NISA 1800 JDT 3125).
Core Cooling: Currently fresh water injection with no boron, injecting through feedwater 120
IImin or 31.7 glm (NISA); Injection flow rate will be maintained above the
minimum debris retention injection rate (MDRIR). Recirculation pump seals
have likely failed. (GEH) ;Injection flow rate above MDRIR could not be
maintained through core spray. Assume RHR is not available.
Primary Containment:
Not damaged, 40 psia Drywell and Torus hydrogen and oxygen concentrations are
unknown. The status of the nitrogen purge capability is unknown. An explosive
mixture is possible.
Secondary Containment:
Severely damaged (hydrogen explosion).
Spent Fuel Pool:
Fuel covered, no seawater injected - (JAIF, NISA, TEPCO). The fuel in this pool
is all over 12 years old and very little heat input «0.1 MW) (DOE)
Rad levels:
Other:
NOTE:
DW 4780 R/hr, Torus 3490 Rlhr (source instruments unknown),
Outside plant: 26mRlhr at gate (variable) (INPO 0900 hrs 3/25/11)
Electric power available, equipment testing in progress (JAIF, NISA, TEPCO)
External AC power to the Main Control Room of V-I became available at 11 :30
JDT 312412011. Lighting in Main Control Room operating in V-I.
Reactor water is in the Turbine Building basement (NISA).
Recommendations are based on validity of above assumptions.
Page 1

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/2612011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
ASSESSMENT:
Damaged fuel that may have slumped to the bottom of the core and fuel in the lower region of
the core is likely encased in salt and core flow is severely restricted and likely blocked. The core
spray nozzles are likely salted up restricting core spray flow. Injecting fresh water through the
feedwater system is cooling the vessel but limited if any flow past the fuel. GE believes that
water flow, if not blocked, should be filling the annulus region of the vessel to 2/3 core height.
There is likely no water level inside the core barrel. Natural circulation believed impeded by
core damage. It is difficult to determine how much cooling is getting to the fuel. Vessel
temperature readings are likely metal temperature which lags actual conditions.
The fuel pool is slowly heating and has not reached saturation. Overhead photos (on-3/19) show
entire fuel floor covered by grey-brown debris of building roof.
The primary containment is not damaged.
RECOMMENDATIONS: (for consideration to stabilize Unit 1)
Follow guidelines of SAMG-1, Primary Containment Flooding, Leg RCIF-4, Can you restore
and hold RPV injection rate above the Minimum Debris Retention Injection Rate (MDRIR)?
1. Inject into the RPV with all available resources while maintaining total RPV injection
flow at the current flow rate (must maintain greater than MDRIR). Systems to use are:
a. core spray, even at reduced flow rate
b. feedwater system
c. other systems as they become available
2. Restore nitrogen purge capability. When restored, establish purge and vent cycle to
minimize explosive potential.
3. RPV injection can be maximized when the containment has been purged with nitrogen
and vented.
4. No overt action is necessary to inject into the primary containment. The primary
containment injection flow path is through the RPV.
5. Vent containment: (see Additional Considerations A. I. through A.8. below)
a. To maintain containment pressure below the primary containment pressure limit.
b. As necessary to maintain RPV injection above MDRIR.
Page 2

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
6. Stop injecting from sources outside of primary containment prior to primary containment
water level reaching the drywell vent. The goal is to raise primary containment water
level to at least the top of active fuel (TAF). (see Additional Considerations c.1. through
C.3. below).
Additional Considerations
A. The following considerations apply to containment venting:
1. If the primary containment is vented then purge the drywell with nitrogen at
maximum flow.
2. If the torus is vented then purge the torus with nitrogen at maximum flow.
3. Attempt to inert with nitrogen prior to venting and especially before utilizing
containment spray, but do not delay venting or spraying the containment if that is
needed, just to inert.
4. Steam/condensing could jeopardize inert environment, as the spray will remove steam
which is preventing hydrogen detonation
5. Hydrogen gas production is more prevalent in salt water than in fresh water. Oxygen
from the injected seawater may come out of solution and create a hazardous
atmosphere inside primary containment. The radiolysis of water will generate
additional oxygen. Maintain venting capability.
6. Containment spray should be secured before 2 psig to prevent opening vacuum
breakers.
7. Spray water on steam plumes and planned containment vents for scrubbing effect.
8. Avoid atmospheric thermal inversion (in the afternoon) when venting to minimize
dose.
B. Additional Miscellaneous considerations
1. When flooding containment, consider the implications of water weight on seismic
capability of containment.
2. Borate water if possible. (With salt in vessel, consider effect of acidic conditions in
vessel when deciding how much boron to add.)
Page 3
Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
3. Ensure spent fuel pool level is maintained as full as possible.
4. CRD injection is desired for cooling directly to the core and for cooling material on
bottom of vessel.
C. Potential methods for monitoring containment level:
1. HPCI suction pressure
2. Drywell instrument taps
3. Radiation monitoring instruments
Page 4

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We that the information is to and refinement.
UNIT TWO
ASSUMPTIONS: (based on input from multiple data source: JAIF, NISA, TEPCO, & GEH)
Core Status: Core is contained in the reactor pressure vessel, reactor water level is unknown.
Core Cooling: Fresh water with boric acid injection (TEPCO), bottom head temperature 104C,
feed water nozzle temperature 107C (NISA 1800 JDT 3/25/11) (JAIF, NISA,
TEPCO) Recirculation pump seals have likely failed. (Industry)
Primary Containment:
Damage suspected (JAIF, NISA, TEPCO)
Secondary Containment:
Damaged (JAIF, NISA, TEPCO), hole in refuel floor siding (visual).
Spent Fuel Pool:
Fuel covered, seawater injected on March 20, fuel pool temperature 52°C (JAIF,
NISA, TEPCO 1800 JDT 3/25/11).
Rad Levels: Drywell 4560 R/hr; Torus 154 R/hr (source instruments unknown);
Outside plant: 26mR/hr at gate (variable) (Industry).
Other: External AC power has reached the unit, checking integrity of equipment before
energizing.
ASSESSMENT:
Damaged fuel may have slumped to the bottom of the core and fuel in the lower region of the
core is likely encased in salt, however, the amount of salt build-up appears to be less than U-l,
based on the reported lower temperatures. Core flow capability is in jeopardy due to continued
salt build up.
Injecting water through the RHR system is cooling the vessel, but with limited flow past the fuel.
Water flow, if not blocked, should be filling the annulus region of the vessel to 2/3 core height.
Based on the reports of RPV level at one half core height, the reactor vessel water level is
believed to be even with the level of the recirculation pump seals, implying the seals have failed.
While core flow capability may be affected due to continued salt build up, RPV water level
Page 5

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/2612011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
indication is suspect due to environment. Natural circulation believed impeded by core damage.
It is difficult to determine how much cooling is getting to the fuel. Vessel temperature readings
are likely metal temperature which lags actual conditions.
Low level release path: fuel damaged, reactor coolant system potentially breached at
recirculation pump seals, primary containment damaged resulting in low level release.
There may be some scrubbing of the release if the release path is through the torus and water
level is maintained in the torus.
Fuel pool is heating up but is adequately cooled.
NOTE: Recommendations are based on validity of above assumptions.
RECOMMENDATIONS: (for consideration to stabilize Unit 2)
Follow guidelines of SAMG-l, Primary Containment Flooding, Leg RCIF-4, Can you restore
and hold RPV injection rate above the Minimum Debris Retention Injection Rate (MDRIR)?
1. Inject into the RPV with all available resources while maintaining total RPV injection
flow at the current flow rate (must maintain greater than MDRIR). Systems to use are:
a. core spray, even at reduced flow rate
b. feedwater system
c. other systems as they become available
2. Restore nitrogen purge capability. When restored, establish purge and vent cycle to
minimize explosive potentiaL
3. RPV injection can be maximized when the containment has been purged with nitrogen
and vented.
4. No overt action is necessary to inject into the primary containment. The primary
containment injection flow path is through the RPV.
5. Vent containment: (see Additional Considerations A.1. through A.8. below)
a. To maintain containment pressure below the pressure limit
b. As necessary to maintain RPV injection above MDRIR
6. Stop injecting from sources outside of primary containment prior to primary containment
water level reaching the drywell vent. The goal is to raise primary containment water
Page 6

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We that the information is to and refinement.
level to at least the top of active fuel (TAF). (see Additional Considerations c.l. through
C.3. below)
Additional Considerations
A. The following considerations apply to containment venting:
1. If the primary containment is vented then purge the drywell with nitrogen at
maximum flow.
2. If the Torus is vented then purge the torus with nitrogen at maximum flow.
3. Attempt to inert with Nitrogen prior to venting and especially before utilizing
containment spray, but do not delay venting or spraying the containment if that is
needed, just to inert.
4. Steam/condensing could jeopardize inert environment, as the spray will remove steam
which is preventing Hydrogen detonation.
5. Hydrogen gas production more prevalent in salt water than in fresh water. Oxygen
from the injected seawater may come out of solution and create a hazardous
atmosphere inside primary containment. The radiolysis of water will generate
additional oxygen. Maintain venting capability.
6. Containment spray should be secured before 2 psig to prevent opening vacuum
breakers.
7. Spray water on steam plumes and planned containment vents for scrubbing effect.
8. Avoid atmospheric thermal inversion (in the afternoon) when venting to minimize
dose.
B. Additional Miscellaneous considerations
1. When flooding containment, consider the implications of water weight on seismic
capability of containment.
2. Borate water if possible. (With salt in vessels, consider effect of acidic conditions in
vessel when deciding how much boron to add.)
3. Ensure Spent Fuel Pool level is maintained as full as possible.
Page 7

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
4. CRD injection is desired for cooling directly to the core and for cooling material on
bottom of vessel.
C. Potential methods for monitoring containment level:
1. HPCI suction pressure
2. Drywell instrument taps
3. Radiation monitoring instruments
Page 8

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
UNIT THREE
ASSUMPTIONS: (based on input from multiple data source: JAIF, NISA, TEPCO, & GEH)
Core Status: Core is contained in reactor vessel, reactor water level is unknown.
Core Cooling: Freshwater injection via fire line initiated 1802 JDT 3/25/11 (NISA), bottom head
temperature l1IC, feed water nozzle temperature Unreliable (JAIF, NISA 1800
JDT 3/25/11, TEPCO) Recirculation pump seals have likely failed.
Primary Containment
Damage suspected (NISA, TEPCO) "Not damaged" (JAIF 10:003/25)
Secondary Containment
Damaged (JAIF, NISA, TEPCO)
Spent Fuel Pool
Low water level (JAIF, NISA, TEPCO), spraying and pumping sea water into the
SFP via the Cooling and Purification Line (NISA)
Rad Levels: DW 5100 R/hr, torus 150 R/hr (Industry);
Outside plant: 26mR/hr at gate (variable) (Industry); 100 R/hr debris outside Rx
building (covered).
Other: External AC power has reached the unit, checking integrity of equipment before
energizing.
ASSESSMENT:
Damaged fuel may have slumped to the bottom of the core and fuel in the lower region of the
core is likely encased in salt, however, the amount of salt build-up appears to be less than U-l,
based on the reported lower temperatures. Core flow capability is in jeopardy due to continued
salt build up.
Injecting water through the RHR system is cooling the vessel, but with limited flow past the fuel.
Water flow, if not blocked, should be filling the annulus region of the vessel to 2/3 core height.
Based on the reports of RPV level at one half core height, the reactor vessel water level is
believed to be even with the level of the recirculation pump seals, implying the seals have failed.
While core flow capability may be affected due to continued salt build up, RPV water level
Page 9

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
indication is suspect due to environment. Natural circulation believed impeded by core damage.
It is difficult to determine how much cooling is getting to the fuel. Vessel temperature readings
are likely metal temperature which lags actual conditions.
Low level release path: fuel damaged, reactor coolant system potentially breached at
recirculation pump seals, primary containment damaged resulting in low level release.
There may be some scrubbing of the release if the release path is through the torus and water
level is maintained in the torus.
Fuel pool is heating up but is adequately cooled, and fuel may have been ejected from the pool
(based on information from TEPCO of neutron sources found up to 1 mile from the units, and
very high dose rate material that had to be bulldozed over between Units 3 and 4. It is also
possible the material could have come from Unit 4). Unit 3 turbine building basement has
flooded. Samples of water indicate some RCS fluid is present (TEPCO sample table - 3/25/11).
Several possible sources (MSIV leakage, FW check valves, Rx building sump drains) were
identified, however the likely source is the fire water spray onto the reactor building. Additional
evaluation is needed.
RECOMMENDATIONS: (for consideration to stabilize Unit 3)
Follow guidelines of SAMG-1, Primary Containment Flooding, Leg RCIF-4, Can you restore
and hold RPV injection rate above the Minimum Debris Retention Injection Rate (MDRIR)?
1. Inject into the RPV with all available resources while maintaining total RPV injection
flow at the current flow rate (must maintain greater than MDRIR). Systems to use are:
a. core spray, even at reduced flow rate.
b. feedwater system.
c. other systems as they become available.
2. Restore nitrogen purge capability. When restored, establish purge and vent cycle to
minimize explosive potential.
3. RPV injection can be maximized when the containment has been purged with nitrogen
and vented.
4. No overt action is necessary to inject into the primary containment. The primary
containment injection flow path is through the RPV.
5. Vent containment: (see Additional Considerations A.1. through A.8. below)
a. To maintain containment pressure below the pressure limit.
b. As necessary to maintain RPV injection above MDRIR.
Page 10

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GER, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
6. Stop injecting from sources outside of primary containment prior to primary containment
water level reaching the drywell vent. The goal is to raise primary containment water
level to at least the top of active fuel (TAF). (see Additional Considerations C.l. through
C.3. below)
Additional Considerations
A. The following considerations apply to containment venting:
1. If the primary containment is vented then purge the drywell with nitrogen at
maximum flow.
2. If the torus is vented then purge the torus with nitrogen at maximum flow.
3. Attempt to inert with nitrogen prior to venting and especially before utilizing
containment spray, but do not delay venting or spraying the containment if that is
needed, just to inert.
4. Steam/condensing could jeopardize inert environment, as the spray will remove steam
which is preventing hydrogen detonation.
5. Hydrogen gas production is more prevalent in salt water than in fresh water. Oxygen
from the injected seawater may come out of solution and create a hazardous
atmosphere inside primary containment. The radiolysis of water will generate
additional oxygen. Maintain venting capability.
6. Containment spray should be secured before 2 psig to prevent opening vacuum
breakers.
7. Spray water on steam plumes and planned containment vents for scrubbing effect.
8. Avoid atmospheric thermal inversion (in the afternoon) when venting to minimize
dose.
B. Additional Miscellaneous considerations
1. When flooding containment, consider the implications of water weight on seismic
capability of containment.
Page 11

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
2. Borate water if possible. (With salt in vessel, consider effect of acidic conditions in
vessel when deciding how much boron to add.)
3. Ensure Spent Fuel Pool level is maintained as full as possible.
4. CRD injection is desired for cooling directly to the core and for cooling material on
bottom of vessel.
C. Potential methods for monitoring containment level:
1. HPCI suction pressure
2. Drywell instrument taps
3. Radiation monitoring instruments
Page 12

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent availahle data and input from INPO, GER, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
UNIT FOUR
ASSUMPTIONS: (based on input from multiple data source: JAIF, NISA, TEPCO, & GEH)
Core Status: Offloaded 105 days at time at accident (JAIF, NISA, TEPCO)
Core Cooling: Not necessary (JAIF, NISA, TEPCO)
Primary Containment:
Not applicable (JAIF, NISA, TEPCO)
Secondary Containment:
Severely damaged, hydrogen explosion. (JAIF, NISA, TEPCO)
Spent Fuel Pool:
Low water level, spraying with sea water, hydrogen from the fuel pool exploded, fuel
pool is cool heating up very slowly (JAIF, NISA, TEPCO) Temperature is unknown
(NISA).
Rad Levels:
No information.
Other: External AC power has reached the unit, checking electrical integrity of equipment
before energizing. (JAIF, NISA, TEPCO)
ASSESSMENT:
Given the amount of decay heat in the fuel in the pool, it is likely that in the days immediately
following the accident, the fuel was partially uncovered. The lack of cooling resulted in zirc
water reaction and a release of hydrogen. The hydrogen exploded and damaged secondary
containment. The zirc water reaction could have continued, resulting in a major source term
release.
Fuel particulates may have been ejected from the pool (based on information of neutron emitters
found up to 1 mile from the units, and very high dose rate material that had to be bulldozed over
between Units 3 and 4. It is also possible the material could have come from Unit 3).
RECOMMENDATIONS:
Page 13

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
1. Maintain coverage of spent fuel pool with fresh borated water.
2. As possible, put spent fuel cooling and cleanup in service.
UNIT FIVE
ASSUMPTIONS: (based on input from multiple data source: JAIF, NISA, TEPCO, & GEH)
Core Status: In vessel (JAIF, NISA, TEPCO)
Core Cooling: Functional (JAIF, NISA, TEPCO)
Primary Containment:
Functional (JAIF, NISA, TEPCO)
Secondary Containment:
Vent hole drilled in rooftop to avoid hydrogen build up (JAIF, NISA, TEPCO)
Spent Fuel Pool:
Fuel pool cooling functioning Temperature 37.9 C (NISA 18003/25/11) (JAIF, NISA,
TEPCO)
Other: External AC power supplying the unit, Unit 6 (?) diesel generators available. Fuel Pool
Cooling lost when pump failed (JAIF, NISA, TEPCO)
ASSESSMENT:
Unit five is relatively stable.
RECOMMENDATIONS:
Repairs complete on RHR pump used for fuel pool cooling.
Monitor
Page 14

Official Use Only
RST Assessment of Fukushima Daiichi Units,
Based on most recent available data and input from INPO, GEH, EPRI, Naval Reactors (with Bettis and
KAPL), and DOEINE
2100 hrs 3/26/2011
The purpose of this document is to provide the NRC Reactor Safety Team's assessment and recommendations for
the Fukushima-Daiichi reactors to the USNRC team in Japan. Our assessments and recommendations are based on
the best available technical information. We acknowledge that the information is subject to change and refinement.
UNIT SIX
ASSUMPTIONS: (based on input from multiple data source: JAIF, NISA, TEPCO, & GEH)
Core Status: In vessel (JAIF, NISA, TEPCO)
Core Cooling: Functional (JAIF, NISA, TEPCO)
Primary Containment:
Functional (JAIF, NISA, TEPCO)
Secondary Containment:
Vent hole drilled in rooftop to avoid hydrogen build up (JAIF, NISA, TEPCO)
Spent Fuel Pool:
Fuel pool cooling functioning. Temperature 22 C (NISA 1800 JDT 3/25111)
(JAIF, NISA, TEPCO)
Other: External AC power supplying the unit, diesel generators available. Fuel Pool
Cooling lost when pump failed (JAIF, NISA, TEPCO)
ASSESSMENT:
Unit Six is relatively stable.
RECOMMENDATIONS:
1. Monitor
ABBREVIATIONS:
GEH General Electric Hitachi
INPO Institute of Nuclear Power Operations
JAIF Japan Atomic Industrial Forum
NISA Nuclear and Industrial Safety Agency
TEPCO Tokyo Electric Power Company
Page 15

quote:

A while back I posted that all of this is temporary, stop-gap measures in damage mitigation vice a real solution to the problem and that TEPCO really had no clue as to what to do. My opinion has been borne out...

On Friday Toshiso Kosako who is PM Kan's senior advisor on nuclear power & safety resigned in disgust, broadsiding both the GoJ and TEPCO. Here's a bit of the news article:

TOKYO: "A senior nuclear adviser to Japanese Prime Minister Naoto Kan submitted his resignation Friday, saying the government had ignored his advice and failed to follow the law.

Toshiso Kosako, a Tokyo University professor who was named last month as an advisor to Kan, said the government had only taken ad hoc measures to contain the crisis at the crippled Fukushima nuclear power plant.

In a tearful press conference, he said the government and its commissions had taken "flexible approaches" to existing laws and regulations, and ignored his advice after he was named an advisor on March 16. "I cannot help but to think (the prime minister's office and other agencies) are only taking stopgap measures... and delaying the end" of the nuclear crisis, he told reporters.

Tokyo officials had drafted measures to deal with the accident that were not in strict accordance with the law, and the decision-making process had been unclear, he said. "There is no point for me to be here," as the Kan administration had failed to listen to him, said Kosako, an expert on radiation safety."

There is a reason for delaying the end of the situation- TEPCO and the GoJ would have to admit that things are not as rosy as they have been saying. They would have to admit they lied and covered up the severity of the accident from the very beginning. I've also said from the beginning that this is FAR worse than what is being officially released and the GoJ and TEPCO have been hoping that things would get better so the extent of the damage would never be made public.

This plan has backfired in the most ominous way. Governments and business do not like being caught out in lies and will continue to put forth wildly optimistic "plans" for regaining control in order to be seen as "doing something".

Reporting on the true facts in Japan is now a criminal act- differ from the party line and the article gets pulled and your station/website gets fined.

quote:

Bill Gates: Don't dismiss nuclear energy
These days, Microsoft's co-founder has more on his mind than software sales figures or even his charitable work -- namely he wants to help solve the world's energy problems.

FORTUNE -- At WIRED's Disruptive by Design Business Conference today, Bill Gates discussed the current state of energy and potential technology replacements for oil and coal.

Gates suggested there's much more potential for nuclear energy, despite the recent disaster with Japan's Fukushima reactor. As he sees it, nuclear has a "factor million" of energy creation compared with coal. And as he quipped, "coal plants kill, but they only kill a few at a time, which is highly preferred by politicians."

Really, the Fukushima reactor incident in his opinion is evident of just how little nuclear technology has improved over time and how ripe the technology is for innovation and investment.
[..]
He also addressed other potential forms of energy creation, including hydrogen and solar. On the former, Gates was lukewarm at best about its potential as a mainstream source.

"I've never understood that [hydrogen]," he said. "It was never a solution to anything, just a potential way to store energy. . . It's just a chemical, and it's a really nice chemical, but all of our applications are per volume-type applications. And it turns out it's actually quite flammable. A hydrogen flame is very, very hot, but invisible."

Gates broke down solar into three trends: utility girds in deserts, installations on office roofs and commercial spaces, and panels on residential roofs.

"If you want cute, go for stuff on the roof," he said. "If you're interested in the problem, go for the [grids] in the desert." Still, solar has a very long way to go, part of which has to do with battery capacity. [..]

quote:

Op dinsdag 3 mei 2011 23:08 schreef Perrin het volgende:
Is dat rook dat uit de kapotte centrale komt, daar tussen de twee rechter masten in?

[ afbeelding ]

(plaatje van webcam die op de Fukushima 1 kerncentrales staat gericht, paar minuten geleden genomen.. het is daar net ochtend)

quote:

Op woensdag 4 mei 2011 11:57 schreef loop het volgende:

[..]

Dat is (radioactieve) stoom die vrijkomt bij het koelen van de centrale's.

EPA (Environmental Protection Agency) in de VS heeft aangegeven te stoppen met het monitoren van de radioactieve wolk, omdat de waardes te laag zouden zijn en niet verwacht wordt dat deze nog zullen stijgen: http://www.epa.gov/japan2011/data-updates.html

quote:

Op donderdag 5 mei 2011 11:15 schreef Dance99Vv het volgende:
uit de stentor:

TOKIO - Voor het eerst sinds de aardbeving en tsunami van 11 maart zijn werknemers donderdag een van de reactorgebouwen van de zwaar beschadigde Japanse kerncentrale Fukushima Dai-ichi binnengegaan.


Dit heeft de beheerder van de kerncentrale, het elektriciteitsbedrijf Tepco, bekendgemaakt.

Zij gaan in ploegen het ventilatiesysteem in het gebouw in orde maken. Dat moet ervoor zorgen dat de straling wordt geabsobeerd. Pas daarna kan worden geprobeerd het koelsysteem te repareren.

Tot nog toe was de radioactiviteit te hoog voor dit soort werkzaamheden.