Nuclear World after Fukushima Strengthening of Nuclear ...grouper.ieee.org/groups/npec/N12-02_NPEC...1 Nuclear World after Fukushima Strengthening of Nuclear Safety Standards (estimated

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Nuclear World after FukushimaStrengthening of Nuclear Safety

Standards

(estimated at 14-15 m)

Dr. Andrew G. CookJuly 25, 2012

IEEE Conference - July 25, 2012

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IEEE 323, IEEE 344 - Standards & Codes

The IEEE is a thoughtful, respected, enduring international body – it’s impact can reach far, far into the future and help: The uninformed The unknowledgeable The underservedand Those who feel they must act but don’t understand what to do.


3

Tohoku – Energy – Codes & Standards – The IEEE

Set a reasonable, international direction for post Tohoku electric power plant & industrial designs that are:Risk informedPerformance basedTechnically strong & Holistic


4WSJ 3/14/11

Tohoku earthquake & tsunami

over 18,000 dead and missing

>$300B in damage


•3 deaths at nuclear power plants•1 from the earthquake•2 from the tsunami

•No health effects or significant contamination cases amongst the general public

5IEEE Conference - July 25, 2012

Nuclear World after Fukushima Strengthening of Nuclear Safety Standards

The World after Tohoku Strengthening of Safety Standards

X

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The National Diet of JapanFukushima Nuclear Accident

Independent Investigation CommissionThe earthquake and tsunami of March 11, 2011 were natural disasters of a magnitude that shocked the entire world. Although triggered by these cataclysmic events, the subsequent accident at the Fukushima Daiichi Nuclear Power Plant cannot be regarded as a natural disaster. It was a profoundly manmade disaster that could and should have been foreseen and prevented.This was a disaster “made in Japan.” Its fundamental causes are to be found in the ingrained conventions of Japanese culture. Our reflexive obedience; our reluctance to question authority; our devotion to “sticking with the program”; our groupism; and our insularity.The consequences of negligence at Fukushima stand out as catastrophic, but the mindset that supported it can be found across Japan.

IEEE Conference - July 25. 2012

ChairmanKiyoshi KurokawaMedical Doctor, Academic Fellow, National Graduate Institute for Policy Studies; Former President of the SScience Council of Japan.

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25 dead in W.Va. mine blast, worst since 1984

Massey Energy Co.'s sprawling Upper Big Branch mine1.2 million tons of coal in 2009 200 employees total – 12.5% of workforce lost in accident.Massey subsidiary Performance Coal Co. has a history of violations for not properly ventilating highly combustible methane gas After a record low 34 deaths last year, it was believed coal mining had turned the corner on preventing fatal accidentsIn the past year, federal inspectors fined the company more than $382,000 for repeated serious violations"People tend to think Massey does a lot of wrong, but I've been there for 18 years and they've never asked me to do anything unsafe," - minerPoison gases blocked rescuers12 hours to drill vent holes for poison gas and determine if rescue teams would be safe to enter the mine

Gary Quarles, 33 – Deceased.

IEEE Conference - July 25 ,2012


Natural Gas Pipeline explosion September 14, 2008 Appomattox, Virginia

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February 7, 2010, Connecticut Gas Turbine explosion kills 5, injures 27


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San Bruno ExplosionDeath Toll Climbs to 7

San Bruno California – Thunderous pipeline explosionone resident described as ''hell on earth'‘Saw remnants of melted cars in driveways as well as a portion of the ruptured pipeline“It’s a heartbreaker when you see that huge piece of pipeline that just blew up from the rest of the pipelineThe blast raised questions about the safety of similar lines that crisscross towns in AmericaAt least 50 people were hurt, 7 suffering critical injuriesLeft a giant crater and laid waste to dozens of 1960’s-era homes in the hills overlooking San Francisco bay30 inch diameter line ruptured and ignited“It was just an amazing scene of destruction” National Transportation Safety Board vice chairman Christopher Hart said.


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Allentown pipeline explosion revives natural gas worries

Latest in a series of deadly accidents that have raised worries about a form of energy that had a good safety record until recently.Five bodies were found after a natural gas explosion


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Home Explosion Kills 2Suffield, Ohio March 2, 2011

A woman and her grandson were killed Wednesday in an early morning propane explosion that left a crater and scattered pieces of debris an estimated 300 yards. The bodies of Regina M. Proudfoot, 63, and Robert Croft, 21, who lived in the house at 885 Martin Rd., were found in the yard


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Oil Rig Explodes Off Louisiana Coast; 11 Missing and presumed dead

IT SUNKLeaking 200,000 to 4 million gallons/day


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The Piper Alpha Disaster


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BP refinery Explosion – Texas City15 dead, 170 injured

March 23, 2005


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Gas Explosion at Gulf Gasoline Distribution Facility in Puerto Rico

October 23, 2009



Oil Tanker FireFebruary 10, 2009

Off Coast of Dubai

Tanker Collides with Freighter


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Every energy source today has risks, is dangerous & kills people – right now!

- Perspective -



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86% of World’s Energy Produced by Fossil Fuels

35%

26%

25%

6%

6%

Source: EIA 2004 Data* Includes geothermal, solar, wind

Petroleum

Coal

Natural Gas

Nuclear

Hydro

Other*1.4%


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Rising Global Populations Drive a Rising Demand for Energy

Population boom: 6 billion today; 9 billion by 2050 26.3% of the world’s population is under the age of 15Majority of world population growth is coming from rapidly developing nations


Global energy demand to double by 2030

World Electricity Generation by FuelSource: International Energy Agency, 2010 Key World Energy Statistics

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What will this look like in 500 years?


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Impact of Tohoku Earthquake & Tsunami

100% shut down of Japan’s nuclear power plants -Termination of Germany’s nuclear program –Started French policy to go to 50% nuclear –

NRC, NEI, WENRA,…..truly hostages of each other”



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What Important Role Can the IEEE NPEC Play?

Undertake and support a systematic cause analysis.

Set a “standard” as to what constitutes adequate and prudent physical protection.

Set a consistent technical and world wide framework that will provide reasonable assurance of public safety.

Set a thoughtful, balanced international standard for Post Tohoku design – nuclear & non-nuclear – that is risk informed, performance based, technically strong and holistic.


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EPR External Hazards Design Bases

Accounts for the following external hazards:earthquake,airplane crash,explosion, lightning and electromagnetic disturbances,groundwater,extreme meteorological conditions (temperatures, wind,

rain, etc.), flooding (including tsunami), andsite proximity hazards.


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EPR Safety Approach

Complementary (between active and

passive systems)

Diversity(against

common cause)

Redundancy(against

single failure)

An accident can be a complex series of events: Plant Operators Need the Means to Remain in Control of the Situation,

Whatever Happens

Four safeguard divisions

1

2 3 4

Emergency power sources

Core catcher &Containment spray

The EPR reactor is designed to resist exceptional events and prevent environmental damage to the surroundings


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The Four Train (N+2) Concept

• Each safety train is located within a physically separate building• N+2 concept provides added redundancy for maintenance or safety


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Safety through Defense-in-Depth

AC power Off-site power with at least 2 transmission lines 100% load rejection capability with transition to “house load” operation 4 Emergency Diesel Generators

Automatically started and automatically loaded if LOOP occurs Each Emergency Diesel Generator provided with 7 day supply of fuel oil and lube oil

(continuous rating) 2 Station Blackout Diesel Generators

Automatically started if LOOP occurs and manually loaded if all EDGs fail Each Station Blackout Diesel Generator provided with 1 day supply of fuel oil and lube

oil (continuous rating) For defense-in-depth in Emergency Operating Procedures (EOPs), capable of

powering “other” emergency loads that are not credited for Station Blackout/Severe Accident management (e.g., spent fuel makeup pumps) with appropriate load management

Diversity between Emergency Diesel Generators and Station Blackout Diesel Generators provided by:

- Diverse size (9.5 MW vs. 4.6 MW)- Diverse equipment locations (Emergency Power Generation Buildings vs. Switchgear Building)- Diverse heat rejection methods (water cooled vs. air cooled)- Diverse HVAC (EPGB HVAC vs. Switchgear Building HVAC)- Diverse control power (Class 1E UPS vs. 12 hour UPS)- Separate fuel oil systems (EDG fuel oil vs. SBO DG fuel oil)


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DC power 4 Class 1E Uninterruptible Power Supplies

Each Class 1E DC division supports a Class 1E AC division DC batteries sized for 2 hour capacity (assuming no load shedding) 2 Class 1 E battery chargers per DC division Class 1E battery chargers can be supplied from multiple AC sources:

- One of two Emergency Auxiliary Transformers (connected to Offsite Power)- “House Load” operation following load rejection- Emergency Diesel Generators

- Respective Division- “Neighboring” Division through Alternate Feed

- Station Blackout Diesel Generators- All four divisions directly supplied

2 Twelve (12) -Hour Uninterruptible Power Supplies Supports Severe Accident management functions and can connect to Class 1E buses

to support containment isolation function DC batteries sized for 12 hour capacity (assuming load shedding at 2 hours) 3 battery chargers (total) – 2 dedicated and 1 swing Battery chargers can be supplied from multiple AC sources:

- One of two Nuclear Auxiliary Transformers (connected to Offsite Power)- “House Load” operation following load rejection- Station Blackout Diesel Generators


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Core Cooling Secondary heat removal with diverse flowpaths

4 Non-safety-related Main Feedwater pumps 1 Non-safety-related Startup Feedwater pump 4 Emergency Feedwater pumps

- 4 EFW pumps backed by EDGs- 2 of 4 EFW pumps backed by diverse, SBO DGs- EFW pools contain 411,000 gallons of inventory (seismically qualified)- Non-safety-related, Demineralized Water Distribution System provides 800,000 gallons of

backup- Non-safety-related, Fire Water System provides 600,000 gallons of additional backup

(seismically qualified)

Secondary heat removal at reduced steam generator pressures 3 Non-safety-related, Fire Water System pumps (1 AC powered + 2 diesel powered) Secondary side depressurization with 4 Main Steam Relief Trains Non-safety-related, Fire Water System provides 600,000 gallons of inventory

(seismically qualified) Operator action to initiate diverse, secondary heat removal within 1.5 – 2 hours


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Core Cooling (continued) Primary heat removal with functionally diverse Feed and Bleed

cooling 4 Medium Head Safety Injection pumps backed by EDGs 4 Low Head Safety Injection pumps backed by EDGs Primary side depressurization with Pressurizer Safety Valves or non-

safety-related, Severe Accident Depressurization paths IRWST contains 500,000 gallons of borated inventory Containment heat removal from IRWST via diverse flowpaths

- 4 Low Head Safety Injection pumps/heat exchangers through the Component Cooling Water/Essential Service Water/UHS cooling chain

- 1 Severe Accident Heat Removal pump/heat exchanger through Dedicated Component Cooling Water/Dedicated Essential Service Water/UHS cooling chain (non-safety-related)


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Spent Fuel Pool Cooling 2 Spent fuel pool cooling trains

Each train contains 2 pumps (in parallel) and 1 heat exchanger (in series) Spent fuel pool cooling pumps backed by EDGs Seismically qualified, spent fuel pool contains 381,000 gallons of borated inventory

2 Spent fuel pool makeup trains Spent fuel pool makeup pumps backed by EDGs Makeup water source (~50,000 gallons) contained in transfer compartment or cask

loading pit (both seismically qualified) Supplemental spent fuel pool makeup capability

Non-safety-related, Demineralized Water Distribution system provides normal makeup 2 Non-safety-related, sump pumps in Fuel Building provide spray cooling of spent fuel

pool. Sump pumps are EDG backed. Re-filling spent fuel pool with seismically-qualified, non-safety-related, Fire Water

System (600,000 gallons) Re-filling spent fuel pool with IRWST (500,000 gallons) Re-filling spent fuel pool with non-safety-related, external water source (grade level)


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Emergency Response Capabilities for the U.S. EPR

Emergency Operating Procedures (EOPs) EOPs for the U.S. EPR are symptom-based procedures that provide

guidance for the operator to mitigate transients without having to diagnose a specific event. EOPs are developed by incorporating U.S. EPR specific analyses of both design bases events and beyond design bases events, as required by NUREG-0737 and other requirements.

Severe Accident Management Guidelines (SAMGs) AREVA has developed a new approach to SAMGs in a project called

Operating Strategies for Severe Accidents (OSSA). The OSSA framework makes maximum use of the lessons learned to date in the field of severe accidents and incorporates a number of new features which simplify and streamline the guidance, while maintaining comprehensive guidance for response to any severe accident.

Extensive Damage Management Guidelines (EDMGs) The 50.54(hh) Mitigation Strategy developed by the U.S. EPR COL

Applicants reestablishes or creates alternative capabilities for EOPs and creates beyond DBA capabilities to fulfill key safety functions performed by Emergency Response Organizations.


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U.S. EPR robustness was evaluated by analyzing the consequences of external hazards beyond the design basesFukushima experience was chosen as a “case study” for

beyond design bases external hazardsEarthquake and flooding characteristics from Fukushima

were selected: Earthquake ~ 1.24 X design basis earthquake [ ~ 0.56g peak

horizontal ground acceleration at site with 0.45g design basis earthquake]

Tsunami / flooding ~ 8.3 – 9.3 m above design value [4-5 m above grade level]

Robustness for External Events


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1

Seismic Event and Tsunami (Flooding)

Earthquake U.S. EPR is designed to withstand a 0.3g peak ground

accelerationPeak ground acceleration at Fukushima was about 1.24 X

design basis earthquakeSeismic Margin Assessment [FSAR Chapter 19.1.5.1]

demonstrates with high confidence that an earthquake 1.67 x design basis earthquake would not have impaired the plant capabilities to mitigate accidents

U.S. EPR design margins are sufficient to accommodate significant beyond design basis earthquakes


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Tsunami (flooding)Grade level for U.S. EPR is at least 1 foot above the maximum

design flooding level for the plantMaximum flooding level at Fukushima was about 8.3 – 9.3

meters (27 – 31 feet) above the design flooding level Equivalent flood for U.S. EPR in Design Certification would be 26-30 feet above grade

Beyond design basis flooding analysis must consider water ingress and structural integrity of buildings. Scope of buildings includes all Class 1 structures: NI Common Basemat (Reactor Building, Safeguards Buildings and

Fuel Building) – Design Certification scope EDG buildings – Design Certification scope UHS cooling towers – Design Certification scope UHS makeup structure – Site Specific COL scope

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Robustness of the U.S. EPR: Seismic Event and Tsunami (Flooding)


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Safeguard Buildings 1 and 4 Safeguard Buildings 2 and 3


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Tsunami (flooding)Impact of beyond design basis Fukushima flood Impact of water ingress:

NI common basemat buildings, EDG buildings and UHS towers protected with air intakes/exhausts well above design flooding level. Air intakes/exhausts for NI buildings, EDGs buildings and UHS towers located at least 39 feet (~ 12 meters) above grade which protects against water ingress and debris ingress (provides ~ 9 feet of additional margin for case study).

Leak resistant doors at grade level — Leak tight doors at grade level can be specified depending on site-specific flooding margin (existing COLA sites for U.S. EPR have at least 49 feet of margin for severe flooding hazards).

UHS makeup structure may be damaged by beyond design basis flood — Site specific. Other alternatives can provide 30 day supply of water.

UHS cooling towers have between 3 to 6+ days of water capacity in basins. Significant time available to replenish UHS cooling towers. UHS decoupled from makeup water source that can be impaired by a tsunami/flooding.

NI common basemat buildings, EDG buildings and UHS cooling towers maintain structural integrity with Fukushima flood level (scoping assessment).

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U.S. EPR design margins are sufficient to accommodate significant beyond design basis flooding



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U.S. EPR plant response follows BTP 5-4, Safety-Grade Cold Safe Shutdown

With Fukushima-like event, U.S. EPR operational response: Physical protection of ESF equipment – All ESF equipment within DC

scope protected [UHS makeup conservatively assumed to be lost]

Initiating event – LOOP (Chapter 15 accident)

End state – Hot Standby (with potential to transition to Cold Shutdown) Core Decay Heat – Removed by safety-related, Emergency Feedwater Spent Fuel Decay Heat – Removed by safety-related, Spent Fuel Cooling Power – Supplied by safety-related, Emergency Diesel Generators Heat Sink – Supplied by safety-related, UHS towers



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Simplified Extended Timeline following Fukushima-like event

T0 2+ days

Safe Shutdown

with Seismically-

qualified SSCsRefill EFW

Tanks

Refill EDG fuel oil and

lube oil

Safe State

Earthquake+ LOOP +

Loss of UHSMakeup

> 14+ days

6+ days

Refill UHS Towers

Hot StandbyHot Standby

Cold Shutdown

Cold Shutdown

Refill EDG fuel oil and

lube oil

Safe State14+ days

(Y)

(N)


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To prevent containment breach and subsequent environmental damage:Prevent highly energetic events, No high pressure core melt No H2 explosion No steam explosion

Achieve long-term core melt stabilization

Prevention of Environmental Damage

Deterministic approach for severe accident mitigation

However low the probability of a severe accident for the U.S. EPR design, consequences to the public are too severe to be

ignored.

2

1


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Prevention of Environmental Damage No High Pressure Core Melt

Primary loop depressurizationPrimary loop depressurization

Pressurizer safety valves

Dedicated severe accidentdepressurization valves

(2 x 2 valves)

Core melting at high system pressure can potentially lead to loss of containment integrity and major melt dispersal

The EPR design includes additional dedicated primary depressurization valves


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► Reduce H2 quantity:Passive Autocatalytic Recombiners

► Minimize H2 concentration :Large reactor building withinterlinked compartments

Prevention of Environmental Damage

No H2 Explosion

U.S. EPR limits global H2 concentration in containment to < 10% by volume during beyond design basis events resulting from fuel clad-coolant reaction of 100% of the cladding in the active fuel region.


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Prevention of Environmental Damage No Steam Explosion

The EPR manages core melt with the core catcherEx-vessel steam explosions can occur when melt pours into a water poolWith the core catcher, the presence of water is excluded by design In the reactor pit In the core catcher before

spreadingNo possibility of steam explosion

Core catcherCore catcher


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Long-Term Melt Stabilization and Cooling

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Severe Accident Heat Removal

system


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Why Do These Facilities Get A Free Pass?

RefineriesStorage facilitiesPipelinesDamsChemical plantsSanitation plantsCivil structuresResidential structures


Overwhelmingly the largest & most enduring impact of Tohoku

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IEEE 323, IEEE 344 - Standards & Codes

The IEEE is a thoughtful, respected, enduring international body – it’s impact can reach far, far into the future and help:

The uninformed The unknowledgeable The underservedand Those who feel they must act but don’t understand what to do.


50

Tohoku – Energy – Codes & Standards – The IEEE

Set a reasonable, international direction for post Tohoku electric power plant & industrial designs that are:Risk informedPerformance basedTechnically strong & Holistic


51

They need you


ALL OF THEM!

Documents

Nuclear World after Fukushima Strengthening of Nuclear ...grouper.ieee.org/groups/npec/N12-02_NPEC...1 Nuclear World after Fukushima Strengthening of Nuclear Safety Standards (estimated