Hydrologic Reviews in

response to the Fukushima

Dai-ichi Incident in Japan

Barbara Hayes, PE, PMP, PhD

Office of New Reactors, DSEA/RHMB

December 2013

1

• NRC, Role and History

• Regulatory Context for Flooding and

other Natural Hazard Reviews: Reviews

of New Applications

• US NRC Response to Fukushima –

Hydrologic Reviews of Operating Plants

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Section 1: NRC, Role and History

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Atomic Energy Commission

• Created in 1946 - transferring

lead role in atomic energy from

military to civilian hands

• Atomic Energy Act Amendment of 1954

promote peace time use of nuclear power

regulate nuclear power including standards

and restrictions governing design, location,

and operations

• Dissolved 1975

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Energy Reorganization Act of 1974

• Separated the regulatory functions of the Atomic Energy Commission from its responsibilities

• Established NRC to regulate the commercial uses of nuclear materials

• Established the Energy Research and Development Administration to assume all other Atomic Energy Commission responsibilities

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(as of Sept 2011)

Section 2: Regulatory Context for

Flooding and other Natural Hazard

Reviews: Reviews of New Applications

7

NRC Licensing Review Key Steps

and Milestones

Public Meetings on

Environmental Review

NRC

Staff

Review

Application

submitted

Licensing

Decision

Mandatory and/or

Contested

Hearing

Safety Evaluation

ReportTechnical Meetings on

Safety Review

Advisory Committee

On Reactor Safety

Review/

Meetings

Environmental Impact

Statement (EIS)

Regulations

10 CFR

Part 20

Part 30

Part 50

Part 51

Part 55

Part 70

Part 73

Part 100

Part 140

Hierarchy of NRC Licensing Tools

Policy Statements

Standard Review Plans

Regulatory Guides

Interim Staff Guidance

Key Regulations for NPP

10 CFR Part 50

10 CFR Part 51

10 CFR Part 52

10 CFR Part 100

Atomic Energy Act of 1954

National Environmental Policy Act of 1969

Energy Reorganization Act of 1974

Laws

Regulations

Guidance

Accident

Dose consequences

Radiation Protection/

Emergency and Security

Planning

Meteorology

Demographics

Hydrologic Sciences

(Surface and Groundwater)/

Flooding/Tsunami

Storm Surge

Cooling Systems

Seismology/Geology/

Geophysics

Issues Considered in Safety

Evaluations

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External Hazards

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Regulatory Framework Regulatory Guides: NUREG-0800 SRP 2.4, RG 1.59 Design

Basis Floods for Nuclear Power Plants and others

Regulations:

10 CFR Part 100 – identifying and evaluating hydrological

features of the site.

10 CFR Part 50 Appendix A, GDC 2 - Design Basis for

Protection Against Natural Phenomena

Structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seicheswithout loss of capability to perform their safety functions.

10 CFR Part 52 : [52.17(a)(vi) for ESP and 52.79(a)(1)(iii) for COL – identifying hydrologic characteristics of the proposed site with appropriate consideration of the most severe of the natural phenomena historically reported.

Hydrology Safety Review Areas

1 Descriptive Hydrology

2 Historic Flood

3 Local Precipitation

/River & Streams

Floods

4 Dam Failure

5 Surge & Seiche

6 Tsunami Hazards

7 Ice Effects

8 Cooling Water Canals

and Reservoirs

9 Flood Protection

10 Channel Diversions

11 Low Water

12 Ground Water

13 Effluent Transport 12

Analysis completed

using a

deterministic

probable maximum

concept

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2.4.1 Hydrologic Description

1 Interface of the Plant with the Hydrosphere

2 Hydrological Causal Mechanisms

3 Surface & Groundwater Uses

4 Data (spatial & temporal, site relevant)

5 Alternate Conceptual Models

6 Other Site-Related Evaluation Criteria

7 Additional Info for 10 CFR 52 Applications

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Flood history at the site

Identification of potential mechanisms for flooding at the site

Computation of local-intense precipitation

Local Flooding & Drainage Design

Combined Events

2.4.2 Floods

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2.4.3 Probable Maximum Flood

1. Design Bases for Flooding in Streams & Rivers

Computation of the PMP over the watershed

Computation of the PMF maximum water level at the site in

combination with other effects (wind wave, surge, etc).

2. Design Bases for Site Drainage

Produced by 2.4.2 local-intense precipitation

Potential effects of erosion and sedimentation

Rainfall-runoff processes are modeled to estimate flooding

conditions at the site.

3. Other Site-Related Evaluation Criteria

4. Additional Info for 10 CFR 52 Applications

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Severe Breaching of an Upstream Dam

Domino Type or Cascading Dam Failures

Dynamic Effects on Structures

Loss of Water Supply due to Failure of

Downstream Dam.

Effects of Erosion and Sedimentation

Failure of On-Site Water Control or Storage

Structure

2.4.4 Potential Dam Failures

2.4.5 and 2.4.6 Storm Surge, Seiche and Tsunami

2.4.5 Probable Maximum

Surge and Seiche Flooding

Meteorological Parameters

(wind speed & direction,

fetch, storm tracks,

historical storm events)

Bathymetry and

Hydrographic

Characteristics

Surge and Seiche Water

levels

Wave Action

Resonance

Protective Structures

2.4.6 Probable Maximum

Tsunami Hazards

Probable Maximum

Tsunami

Historical Tsunami Record

Source Generator

Characteristics

Tsunami Analysis

Tsunami Water Levels

Hydrographic and Harbor

or Breakwater Influences

Effects on Safety-Related

Facilities

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2.4.7 Ice Effects

Review areas include:

Historical ice

High & low water levels

Ice forces and blockage

Consecutive degree days below freezing

Develop design basis conditions for site

Ensure that safety-related SSCs and water supply are not affected by ice-induced hazards

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Review of stream channel diversions

away from the site, which may lead

to loss of safety-related water.

Review of stream channel diversions

toward the site which may lead to

flooding.

2.4.9 Channel Diversions

• Section 3: US NRC Response to

Fukushima – Hydrologic Reviews of

Operating Plants

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Japan Lessons Learned

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2011 Tohoku Earthquake

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• Commission directed a

methodical and systematic review

of the safety of U.S. facilities in

light of events in Japan

• Review includes:

– Near-term review

– Longer-term review

• Near-Term Task Force

review complete

NRC Lessons Learned Review

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Recommendations

• NRC established the Near-Term Task Force (NTTF)

in response to events at Fukushima Dai-ichi in

March 2011

• NTTF developed a set of twelve overarching

Recommendations

• Recommendation Two included:

– Flooding Hazard Reevaluations and Walkdowns

– Seismic Hazard Reevaluations and Walkdowns

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Scope: NTTF Recommendation 2.1

• Reevaluate hazards at all operating reactor sites

• Collect information to facilitate NRC’s determination

if there is a need for additional regulatory actions

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Scope: NTTF Recommendation 2.3

• Develop seismic and flooding walkdown procedures

• Perform walkdowns using NRC-endorsed walkdown

Methodology

• Identify and address degraded, non-conforming or

unanalyzed conditions

• For flooding hazards only, identify and address any

cliff-edge effects, NTTF defined “Cliff-Edge” effect: safety

consequence of a flooding, event may increase sharply

with a small increase in flooding level.

By letter to licensees, Recommendations 2.1 and 2.3 are initiated via

requests for Hazard Re-evaluation Reports and Walkdown Reports

CFR 10 – Part 50.54 Conditions of licenses

(f) The licensee shall at any time before

expiration of the license, upon request of the

Commission, submit, as specified in § 50.4,

written statements, signed under oath or

affirmation, to enable the Commission to

determine whether or not the license should

be modified, suspended, or revoked…..26

March 2012: 50.54(f) letter

Flood Hazard Approach

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Recommendation (R) 2.3 –Flooding Protection Walkdowns

R2.1 – Flooding Hazard Reevaluations and Interim Actions

R2.1- Integrated Assessment(if required)

Regulatory Actions(if appropriate)

R2.2 – Periodic Reevaluations of new and significant information

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Timeline for Walkdowns:

NRC Request for Information letter related to

seismic, flooding, and emergency preparedness

(March 12, 2012)

Industry-issued guidance (with NRC guidance” for

conducting flooding walkdowns (NEI 12-07) (May

2012)

Guidance for NRC inspectors to review the

flooding walkdowns (temporary instruction

2515/187)(June 27, 2012)

Status: All flood walkdown reports completed by

licensees and under review by NRC staff.

Summary of Licensee

Flood Walkdown Reports• Approximately 90% of licensees entered an issue into

its Corrective Actions Program

• Issues are being addressed through licensees’

Corrective Actions Program and NRC’s Reactor

Oversight Process

• Level of detail in some licensee reports make it difficult

for the staff to fully understand the plant’s flood

protection features

• Several licensees identified that their flood protection

maintenance and monitoring programs were ineffective29

Staff Observations from Licensee

Walkdown Reports• Common issues identified include:

– Inadequate procedures

– Flood protection features that may not

perform as planned

– Degraded or missing seals

• Flood protection enhancements were identified:

– Procedural improvements

– Improve or develop preventive maintenance

programs 30

Cliff-Edge Effects versus

Available Physical Margin

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Significant Safety Consequence if Water Overtops Flood Gate

Temporary Internal Flood Gate with Inflatable Gasket Seals

Flood Walkdown Audits

Audit locations selected based on:1.Information on flood levels from co-located new

licensing reviews

2.Sites with ongoing regulatory actions or a site-specific

event that challenged the flood protection.

3.Walkdown reports with issues related to

documentation, manual actions and/or flood barrier

deficiencies entered into Correct Action Program.

4.Insights from resident inspectors and regions

5.Available Physical Margin (APM) are small with possibly

significant safety consequences.

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Flood Walkdown Audit

Sites

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Overall Approach: R2.1: Flood Hazard Reevaluation

– Phase 1 (approximately 5 years):

• Licensees reevaluate flooding and seismic hazards

using present- day regulatory guidance and

methodologies

• If necessary, perform an integrated/risk assessment

following the hazard reevaluation

– Phase 2:

• Based on results of Phase 1, NRC will determine if

further regulatory actions are necessary to protect

against the updated hazard

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R 2.1: Flooding Hazard Reevaluation

• Hazard reevaluation should be consistent with

regulatory guidance and methodologies used for

Early Site Permit (ESP) and Combined License (COL)

reviews

NUREG-0800, “Standard Review Plan” Section

2.4

CR-7046, “Design Basis Flood Estimate for

SiteCharacterization of Nuclear Power Plants in

the USA”

• Evaluation should discuss all flood-causing

mechanisms.

• Mechanisms that are not applicable at a site may be

screened-out; however, a justification should be

provided.

Flooding Hazard

Reevaluations: Categories

Category 1

Due 03/12/2013

Category 2

Due 03/12/2014

Category 3

Due 03/12/2015

Callaway Quad CitiesArkansas

Nuclear OneFort Calhoun Bellefonte Perry

Calvert Cliffs Salem Beaver Valley Robinson Brunswick Pilgrim

Comanche Peak Sequoyah Braidwood Farley Crystal River Point Beach

Dresden Shearon Harris Browns Ferry Kewaunee Diablo Canyon Ginna

Fermi South Texas Byron LaSalle DC Cook San Onofre

Grand GulfThree Mile

IslandCatawba Monticello FitzPatrick Seabrook

Hope Creek Turkey Point Clinton Palo Verde Limerick St. Lucie

Indian Point Vermont Yankee Columbia Peach Bottom Millstone Surry

Nine Mile Point Summer Cooper Prairie Island Oyster Creek Susquehanna

North Anna Vogtle Davis-Besse River Bend Palisades Waterford

Oconee Watts Bar Duane Arnold McGuire

Hatch Wolf Creek

COUNT= 22 COUNT= 24 COUNT= 20

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delayed

R2.1 Flood Hazard Reevaluation

• Review focuses on comparison of

Design Basis to Re-evaluated Flood

Hazards to identify the need for

further analysis

• Preliminary review of reports

submitted to date suggest a majority

of the sites will perform an integrated

assessment

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Plant Extension

Requested Thru

Extension

Approved?

(Y/N)

* Interim

Actions?

(Y/N)

* Integrated

Assessment?

(Y/N)

Callaway N/A N/A N N

Calvert Cliffs N/A N/A Y Y

Comanche Peak N/A N/A N Y

Dresden Submitted 5/10/2013Y

[ML13095A320]Y Y

Fermi N/A N/A N N

Grand Gulf N/A N/A N Y

Hope Creek March 2014Y

[ML13095A281]N -

Salem March 2014Y

[ML13095A281]N -

Indian Point December 2013Y

[ML13095A297]Y -

Nine Mile Point N/A N/A Y Y

North Anna N/A N/A Y Y

38* Based on licensee submittal currently under evaluation by staff.

Category 1: Summary

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Plant Extension Requested

Thru

Approved?

(Y/N)

* Interim

Actions?

(Y/N)

* Integrated

Assessment?

(Y/N)

Oconee N/A N/A Y Y

Quad Cities N/A N/A Y Y

Sequoyah March 2015Y

[ML13163A296]Y -

Watts Bar March 2015Y

[ML13163A296]Y -

Harris N/A N/A N Y

South Texas N/A N/A N N

Three Mile Island N/A N/A N N

Turkey Point N/A N/A Y Y

Vermont Yankee N/A N/A Y Y

V. C. Summer N/A N/A Y Y

Vogtle N/A N/A N Y

* Based on licensee submittal currently under evaluation by staff.

Cat 1: Summary – continued

Summary of Progress

• Issued all guidance documents for addressing

recommendations.

• Actively completing walkdown report reviews,

which will be documented in a Staff

Assessment.

• Actively completing review of the 17 hazard

reevaluation reports submitted thusfar, some

with Interim Actions, which will be documented

in Staff Assessments.

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For flood causing mechanisms that are not

bounded by the current design basis:(1) evaluate the effectiveness of the current licensing

basis under reevaluated flood hazard,

(2) identify plant-specific vulnerabilities, and

(3) assess the effectiveness of existing or planned plant

systems and procedures

Interim Staff Guidance Issued Nov 2012

– All licensees committed to use the

guidance (if needed)

Flooding Integrated

Assessments

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______

Next Steps & Challenges

• Continuing to coordinate with other federal

agencies regarding specific dams

– Evaluations involving dams that can potentially flood a

nuclear power plant site require close coordination with our

federal partners and protection of sensitive, unclassified,

data.

• Importance of details associated with staff review

of the flood hazard reevaluation reports.

• Actively preparing for second set of hazard

reevaluation report submittals this spring (24 sites).

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Thank you!

Questions?