safety culture after fukushima - ieee-sa - working …grouper.ieee.org/groups/npec/n12-02_npec...

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© 2011 Westinghouse Electric Company LLC. All Rights Reserved.Westinghouse Proprietary Class 3Westinghouse Proprietary Class 3 © 2012 Westinghouse Electric Company LLC. All Rights Reserved.

Safety Culture After Fukushima

David HowellIEEE NPEC MeetingJuly 25, 2012

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© 2012 Westinghouse Electric Company LLC. All Rights Reserved.Westinghouse Proprietary Class 3

Today’s Westinghouse

Focused on operating plant success through reliable operation, maximized power output and better (shorter, more predictable) outages

Nuclear Services

Specializing in the technology of new nuclear power plants and component manufacturing

Nuclear Power Plants

A single-source fuel provider for PWR, BWR, VVER, AGR and Magnox reactors worldwide

Nuclear Fuel Nuclear AutomationInstrumentation and control systems to enhance the reliability of nuclear plant control and safety systems

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The World Still Needs Nuclear Power• Nuclear energy will continue to be a major

source of electricity• Expanding population • Need for clean energy• Need for diverse energy portfolio• Retirement and replacement of older

units • Lowest-cost producer of baseload

electricity• Operation of a U.S. nuclear plant

generates up to 700 permanent jobs• 3500 construction jobs• Average pay 36% more than salaries

in local area

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Fukushima Impact

• Safety Evaluation• What has changed in

our industry as a result of Fukushima?

• What was the impact on new construction?

• What was the impact on operating plants?

• What is the industry doing to respond? Image of damaged reactor at Fukushima Daiichi plant.

©TEPCO

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Global Nuclear Energy Safety Post-Fukushima

March 11, 2011 changed the face of our industry

The Fukushima nuclear plants experienced a series of unprecedented natural disasters that exceeded the design basis:

• Earthquake ground force acceleration of 0.51g vs. design of 0.45g

• Tsunami wave 14 meters high vs. design of tsunami wall at 5.7 meters

Damaged Unit 3 of the Fukushima Dai-Ichi nuclear power plant in Okumamachi, Fukushima Prefecture

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Industry Response

• As an industry, we have a history of examining significant events to find the lessons learned

• The industry took a pause to re-evaluate the impact of this event. This pause changed the timetable for new plant construction

• Interactions with regulator, government and community have all changed

• This has led to impacts to both plants in operation and to AP1000®

units under construction worldwide

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5 Focus Areas of the Regulatory Response

• Improve ability to maintain safety even with an extended loss of electric power

• Add second system to monitor level fuel storage pools• Ensure reliable hardened containment venting on

specific designs (specific to BWR Mark I and II containments)

• Evaluate protection against extreme events (earthquakes, flooding, etc.)

• Enhance emergency planning, staffing for multi-reactor events

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Courtesy of NEI

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What has this meant to Operating Plants?

• The very best operating plants (in the U.S., that’s those rated as INPO 1 or 2), are very good at understanding lessons learned and incorporating operating experiences into future decisions

• Each major country or region with operating nuclear power plants took action to review the safety of its plants:

– U.S.: 90-day post-Fukushima report, INPO plant assessments

– Europe: regulatory requirements still being determined, Nuclear Plant Stress Tests underway

– Asia: Reports and tests vary by country; Japan shut all reactors over the last year to evaluate safety

• Countries with operating nuclear power plants looked to three specific areas to improve: People, Processes and Equipment

One of the most important findings from the many reviews during this period was that plants in operation today are safe

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What does this mean for U.S. industry codes and standards?

• The regulatory reviews, including the 90-day report, have concluded that the plants as they exist today are safe.

• Because our industry embraces Lessons Learned, key U.S.-based international standards development organizations, including ASME, ANS, ASTM and IEEE already have evaluations of key standards underway.Some early specific examples of standard revisionsunder development: • ANS-2.8, "Determine External Flood Hazards at

Nuclear Facilities”• ASME/ANS Probabilistic Risk Assessment Standard

being reviewed for treatment of extreme external events and possible all-risk approach

• IEEE standards being reviewed for treatment of prolonged station blackout events

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Internationally, the story is much the same• Operating plants have been found to be safe,

but some changes to standards may be necessary based on regulatory review.

• The Japan Society of Mechanical Engineers (JSME) is developing a –“Guideline for Management of Severe Accident Due to External Events” to support restart of reactors in Japan; JSME is evaluating about 30 other standards that need to be developed or changed

• The International Atomic Energy Agency also has efforts underway for development of severe accident management guidance

One of the biggest changes post-Fukushima is that we are much less insular as an industry today than we were 18 months ago

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Lessons Learned from Fukushima

• Fukushima reinforced the need to further prepare for the unexpected: Improved defenses for external/environmental

challenges Extended ability to withstand loss of offsite power and

ultimate heat sink (UHS) Increased emphasis on spent fuel pools Evaluation of multi-unit events Better operator training and emergency procedures

• To meet growing energy needs, nuclear must remain a part of the future energy mix, and the events of Fukushima have increased appreciation of passive safety systems, such as those used in the Westinghouse AP1000®

reactor

EFPCS Primary cooling pumps

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© 2012 Westinghouse Electric Company LLC. All Rights Reserved.Westinghouse Proprietary Class 3Westinghouse Proprietary Class 3 © 2012 Westinghouse Electric Company LLC. All Rights Reserved.

Japan•SHIELD® •Filtered vent•UHS•Severe accident management

Korea•Filtered vent

Brazil•SHIELD® •Hydrogen management •Filtered vent

Mexico•Spent fuel pool level measurement, cooling

Package with TSBtechnology, joint proposal

SCiB

Plate Heat Exchanger

Primary Pump

Mobile RHR cooling system

BWR filtered vent

BWR seismic, flood management evaluation

Canada•Hydrogen management•Filtered vent

U.S.•SHIELD® •Spent fuel pool level measurement•Seismic and flood walkdowns and evaluations•FLEX•BWR-reliable, hardened vents•Severe accident management updates, education and training•Hydrogen management

Post-Fukushima Initiatives

Belgium•Filtered vent

Sweden/Nordic•Independent core cooling•Severe accident management•FLEX

Switzerland•Emergency power system•Hydrogen management•Spent fuel pool cooling

France•SHIELD® •Emergency diesel generators•Filtered vent•Fire, flood PRA evaluation•Mobile boron water supply•Sump pH control

Spain•SHIELD® •Filtered vent•Hydrogen management

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What has this meant for new plants?

• Mentality of the industry has changed• Passive Safety Systems became much more attractive• China shifting from Generation II technology to Generation

III with its new build plans

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Summary of Key Conclusions AP1000® Plant Response to Extreme Events• The AP1000® plant passive design assures

– Containment integrity– No fuel damage (both spent fuel and reactor)– No radiological release as a result of the event

AP1000® plant achieves and maintains Safe Shutdown to protect public health and safety

[…], as has been pointed out to me by Japanese colleagues as they reflectupon Fukushima, had the plant been operating AP1000® reactors, it is likelythat the outcome would have been very different. The AP1000®’s passivesafety systems provide the ability to maintain core cooling for at least 72hours with little human intervention. 72 hours to make repairs, transportemergency equipment, and take other actions in response to theearthquake and tsunami that assaulted the Fukushima site would havemade a very significant difference.UR NRC Commissioner William D Magwood

Photo credit: U.S. NRC

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AP1000® Plant Response to Extreme Events• AP1000® plant provides a unique capability to

respond to DB and BDB events due to 3 fundamental safety advancements:

1. AP1000® Plant Self-Actuates. For station blackouts, critical SSCs will automatically achieve a fail safe configuration without the need for operator action or AC/DC power

2. AP1000® is Self-Sustained. AP1000® plant’s passive approach to safety de-emphasizes the importance of AC power and cooling supply.

3. AP1000® is Self-Contained. Systems, structures, and components (SSCs) critical to placing the reactor in a safe shutdown condition are protected in the steel containment vessel and further surrounded by a “steel concrete” composite shield building.

0 25 50 75 100 125 150 175

AP1000

ExistingUS

Plants

NRCRequire

ment

Hours

4 hours

4-8 hours

168 hours

AP1000 ability to cope with Station Blackout

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Sanmen Site Progress, Winter 2009 to Spring 2012

Construction of New Plants has Continued

• AP1000 amended design approved in December 2011 in unanimous 5‐0 vote

• Combined construction and operating license (COL) for Vogtle site approved on February 9, 2012; COL for V.C. Summer site approved on March 30, 2012

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State of Plants in Japan

• All plants shut down in the year since Fukushima

• A number of safety measures implemented in the year since

• Regulators recently approved restart of two units

• Government policy is long-term reduction of nuclear power

Japanese officials and IAEA team members discuss safety measures outside Unit 3 of Japan's Ohi Nuclear Power Plant. Copyright: IAEA ImagebankPhoto Credit: Greg Webb / IAEA

18 Confidential © 2012 Toshiba Corporation

PEX-2012-000030 rev.0Overview of Plant Safety Improvements in Japan

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DG

Ｔ／ＢＲ／Ｂ

Reactor Building Hydrogen Ventilation System

Alternative Power

Fuel

Power Supply CarFire house

Power Panel

Sea Water Pump

Enhancement of Tsunami prevention

Alternative feed water injection system

Plate HeatExchanger

Primary Pump

Plate HeatExchanger

Primary PumpPrimary Pump

Portable RHR Cooling SystemSFP water level monitoring systemStrengthened seal performance

Diversity of Power Supply

Improvement of off-site power supply reliability

Enhancement of ultimate heat sink function

Enhancement of the redundancy and diversity of emergency AC power supply

Enhancement of monitoring system for plant status

Enhancement of alternative water injection system Filter Vent System

Reduction of any vent influence to the environment

Seismic Reinforcement

Breakwater

Prevention of CV damage and Hydrogen Explosion

On-site Power systems

External Power Supply Systems

Core Cooling / Injection system

Core Cooling / Injection system

On-site Power systems

Control and Measurement System

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“America’s choice is clear ‐we can either develop the next generation of clean energy technologies, which will help create thousands of new jobs and export opportunities here in America, or we can wait for other countries to take the lead.

“The funding opportunity announced today is a significant step forward in designing, manufacturing, and exporting U.S. small modular reactors, advancing our competitive edge in the global clean energy race.”

Energy Secretary Steven Chu Draft SMR Funding Opportunity Announcement

January 20th, 2012

Next Generation Nuclear Technology

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Benefits of SMRs

• Small-scale reactors can complement large nuclear plant projects by expanding potential markets in the United States and abroad for carbon-free energy production

• Smaller reactors provide energy companies and other users with additional options that help achieve critical energy and environmental policies

• Their small size—less than 300 megawatts electric—and modular construction mean they can be built in a controlled factory setting and installed module by module, improving manufacturing efficiency and cost while reducing construction time and financing costs

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The Westinghouse SMR

Collaboration with Ameren Missouri at the Callaway Nuclear Generating Station and the NexStart Alliance

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Conclusion

• The current generation of Nuclear plants are safe• The next generation of plants will be safer• Fukushima challenged the way in which we think about the probability

of disasters at nuclear plant sites• Nuclear will continue to be part of the energy equation• Passive safety systems rule the day• SMRs are the next frontier

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