hydrologic reviews in response to the fukushima dai-ichi … · 2013-12-05 · hydrologic reviews...
TRANSCRIPT
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
2
Section 1: NRC, Role and History
3
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
4
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
5
6
(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
10
External Hazards
11
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
13
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
20
Japan Lessons Learned
21
2011 Tohoku Earthquake
22
• 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
23
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
24
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
25
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
27
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
28
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
31
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
37
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
39
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.
40
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
41
______
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?