Current and Future Research and Development … Different approaches used to model transition...

https://lwrs.inl.gov

Current and Future Research and Development

Directions in the Light Water Reactor

Sustainability (LWRS) Program

Fourth International Conference on

Nuclear Power Plant Life Management

October 25,

Bruce P. Hallbert, PhD Director, LWRS Program

Technical Integration Office

Idaho National Laboratory

Goal: Develop fundamental scientific basis to support the continued long-term safe operation of existing LWRs (beyond 60 years) and their long-term economic viability

Objectives

o Enable long term operation of the existing nuclear power plants

o Improve reliability

o Sustain safety

Focus Areas

o Materials Aging and Degradation

o Advanced Instrumentation, Information and Control Systems Technologies

o Risk-Informed Safety Margin Characterization

o Reactor Safety Technologies

Nine Mile Point ~ Courtesy Exelon

Program Goals and Objectives

DOEs program

for LWR RD&D

Understand and predict

long-term environmental

degradation behavior of

materials in nuclear

power plants, including

detecting and

characterizing aging

degradation

Address long-term aging

and obsolescence of

existing instrumentation

and control technologies

and enable plant

efficiency improvements

through a strategy for

long-term modernization

Develop significantly

improved safety analysis

methods and tools

(including RAVEN,

RELAP-7 and Grizzly) to

optimize the safety,

reliability, and economics

of aging plants

Address emerging safety

concerns in response to

the Fukushima accident

Develop technologies to

enhance the accident

tolerance of current and

future reactors

Materials Aging and Degradation Goals

Material Aging and DegradationMaterial Aging and Degradation

Develop predictive model for RPV embrittlement validated through experimental, surveillance and ex-service materials

Understanding mechanisms of IASCC failure and SCC initiation of SS and Ni-base alloys predict and develop mitigation strategies

Produce of a fully coupled thermo-hydro-mechanical-chemical model for reliably predicting the performance of concrete structures

Understand cable degradation modes, predict performance and evaluate rejuvenation strategies

Establish condition monitoring techniques for cables and concrete structures

Development of advanced alloys and strategies

Development of procedures, techniques and computational modeling for advance weld repair

Laser welding/ cladding technology

development

Summary of Materials Aging and Degradation Metals Research

Developing predictive assessment of RPV embrittlement and understanding the responsible mechanisms

o Using extensive data from recent ATR-2 specimen irradiations along with

previous experimental and surveillance databases

o Different approaches used to model transition temperature changes

Continuing IASCC research efforts

o Understanding mechanisms leading to failure

o Water chemistry impact on crack growth rate

Harvested reactor pressure vessel sections from the decommissioned Zion Units

o Determination of variations in base metal

and weldment: influence of attenuation,

compositional variations, microstructure

and property changes

o Evaluation of radiation damage models

o Comparison to surveillance specimens,

computer models, and high flux reactor

experiments


WF-70, Belt-line Weld

B7835-1 Base Metal

Developing technologies for repairing highly irradiated materials, such as reactor internals

Viewing

window

Manipulator

pass-through

Access

door

Sample

pass-through

Fric9on s9r

welding

Laser

welding


Objectives

o Develop advanced welding technologies for repairing highly irradiated

reactor internals without helium-induced cracking

o Demonstrate these technologies on irradiated stainless steels

Recent Accomplishments

o Weld process model for in-situ temperature and stress/strain refined

and validated

o Friction stir weld demonstration of cubicle installed in hot cell

o Irradiated coupons for weld parameter evaluation

Upcoming

o 2017 Begin welding of irradiated materials

o 2018 Transfer of weld repair techniques to industry

o 2021 Examine effects of re-irradiation of weld repaired materials

Developing improved understanding of Alkali-Silica Reaction (ASR) effects on concrete structures

Alkali cement reacts with reactive silica aggregates in the presence of water to form an expansive gel that creates cracking and potentially loss of mechanical properties. Reaction occurs over time and favors elevated temperature and water.

Test Specimens

Three steel rebar reinforced concrete test blocks, ~10 tons of concrete each

Two ASR susceptible blocks and one control

One ASR test block is confined by a steel outer structure (~52 ton structure), the other is

free to expand

Test Chamber

All test specimens contained within an environmental chamber enclosure

to maintain 38 C and 95% relative humidity

Monitoring

Dozens of embedded strain and pressure sensors

Passive acoustic sensors

External techniques being developed to measure

strain development, cracking and condition

monitoring of the test blocks


Project will develop an assessment of the structural significance of ASR damage,

through investigating the role of stress confinement on the development of ASR and its

effect on residual structural shear capacity of thick, reinforced structures.


Developing and evaluating nondestructive evaluation (NDE) techniques for concrete structures

Example of defect (dissolved

styrofoam in concrete - simulates

delamination)

Accomplishments and Continuing Work

Improved existing techniques by using advanced signal

processing

Synthetic Aperture Focusing Technique (SAFT) with frequency

banding

Model Based Iterative Reconstruction (MBIR) techniques

Collaborating with the online monitoring team (Vanderbilt

University and INL) on ASR affected structures.

Conducted Vibro-Acoustic Modulation (VAM) and nonlinear

impact resonance spectroscopy (NIRAS) experiments on

concrete specimens at University of Alabama made of two

different reactive aggregates together with Vanderbilt University


RCFC power cable

Multi-conductor

I&C cables

Understanding cable degradation modes

Processing of harvested, rad/asbestos contaminated cables from Zion Unit 2 completed

Distributed between NRC and DOE labs

Receipt and Asbestos Abatement of Crystal River 3 Cables

Six of the eight most common cables represented in materials harvested from Crystal River for further aging and lifetime assessment

Testing

Combined HFIR aging of harvested cable jacket samples completed

Thermal Degradation of Medium Voltage EPR Insulation identify the indicators for physical/chemical changes to correlate to lifetime predictions

Advanced Instrumentation, Information, and Control System Technologies

Addressing long-term aging and reliability concerns of existing II&C technologies and enabling plant efficiency improvements

o Establish a strategy to implement long-term modernization of II&C systems

o Develop, test, and deploy advanced technologies

o Promulgate technologies, lessons learned, and foster industry standardization

o Reduce technical, financial, and regulatory risks

o Develop advanced condition monitoring technologies to monitor, detect, and characterize aging and degradation processes

Advanced Instrumentation, Information, and Control Systems TechnologiesAdvanced Instrumentation, Information, and Control Systems Technologies

Computer Based Procedures

Developed, tested, and are commercializing technology to transform static paper based procedures into interactive, status-informed and

status-reporting tools that assist work and reduce error.

Business Case Studies

Work with Scott Madden & Associates to evaluate the cost benefit of II&C Pilot Project

Technologies with host utilities to provide

confidence and insights into methods

to best leverage gains.

Advanced Instrumentation, Information, and Control System Technologies Accomplishments

Control Room Modernization

Began with stepwise modernization activities that demonstrate

How To and lessons learned and have moved to broader,

long-term modernization projects with first movers.

Outage Control Centers

Developed technologies deployed at 10 utilities and

recognized in APS TIP Award for managing and coordinating

outages with new technologies.


Industrial Engagement

The purpose of the Working Group is to define and sponsor research projects that will collectively enable significant plant performance gains and minimize operating costs as part of the larger national effort to ensure long-term sustainability of the LWR fleet.

Working Group is guided by a charter to:

Develop agreements with host utilities to demonstrate near-term beneficial digital applications that improve performance at lower cost.

Obtain funding for projects through LWRS program funding and industry cost-sharing.

Coordinate project development among research organizations associated with the U.S commercial nuclear industry, to the degree practical, to minimize duplication of effort.

12

Working on a Pilot Project with APS at Palo Verde to modernize their control room

Recent AccomplishmentsDevelopment is underway for a turbine control system prototype for use in a operator-in-the-loop study, to be held in the Human System Simulation Laboratory using crews from Palo Verde Nuclear Generating Station (PVNGS).

Development activities were completed to conduct a workshop at PVNGS in early August for the Liquid Radwaste control room upgrade.

An analysis of the PVNGS maintenance and surveillance testing program was completed to quantify benefits of I&C and control room modernization.

A cover story in the June 2017 edition of ANS Nuclear News featured recent work under the LWRS program to modernize the main control room at PVNGS.


Risk-Informed Safety Margin Characterization

LWRS

RISMC

Methods

Reliability

Risk

Tools

Grizzly

RAVEN

RELAP-7

External Hazards

Data

Validation

Experiments

Industry Collaboration

Risk-Informed Safety Margin CharacterizationRisk-Informed Safety Margin Characterization

The RISMC

Toolkit is being

created to avoid

the issues and

limitations with

legacy tools

With RISMC, we estimate how close we are (or not) to an undesired state, not just the

frequency of the event, providing information on how safety margins can be improved

Purpose: Inform decisions for risk-informed margins

management to support improved economics, reliability,

and sustain the safety of current nuclear power plants

Goals

1. Develop and demonstrate risk-assessment methods

coupled to safety margin quantification that can be used

by decision makers as part of their margin recovery

strategies

2. Create an advanced RISMC toolkit that enables more

accurate representation (e.g., reduce conservatisms) of

nuclear power plant safety margins

Risk-informed LOCA Tool for U.S. (LOTUS)

o Executing advanced multi-physics demonstrations

Integrating core design, fuel clad performance, systems analysis, and risk analysis

over multiple operating cycles

Better understanding of plant performance and safety margins for 10CFR 50.46c rule

making

o Collaboration with South Texas Project and Texas A&M on best estimate PWR multi-physics demonstration

Benefits

o Efficiency in technical basis for regulations

o Operational improvements (advanced fuels)

o Economic enhancements (higher burn-up)

Extending this R&D to other applications

o Accident tolerant fuel (coping time analysis)

o Fuel burnup analyses (higher burnup fuel)

o 50.69 (risk informed engineering changes)

o Understanding and crediting FLEX operations

Delivering improved safety and efficiency of commercial NPPs through advanced modeling and simulation analysis capabilities


Seeking input and further engagement from industry to transfer

this technology/capability to expand usage and benefits

Developing capabilities and performing analyses to more accurately assess external hazards seismic and flooding

Perform advanced risk analysis with realistic plant models, including combined hazards, i.e., earthquake and flooding

o Dynamic risk analysis

Seismic Analysis

3D Flooding Simulation

Thermal Hydraulics

o Use advanced simulation tools & coupling methods

o Perform realistic risk analysis for a generic PWR/BWR

o Collaborating with Entergy

Impacts:

o Regulatory efficiencies (external hazards re-evaluations)

o Enhanced risk characterization and prioritization (asset management)

o Economic enhancements (hazard avoidance and mitigation)


Reactor Safety Technologies R&D Areas

Fukushima Forensics

o Fukushima Inspections and Evaluations (TEPCO & NRC participating)

o Support international efforts on BDBEs (CNWG meetings)

o Conducted TMI knowledge transfer workshop with Japan

Severe Accident Analysis

o MAAP/MELCOR Crosswalk: Phase-2 on 1F1 in-vessel recovery actions

o In-vessel analysis with MAAP/MELCOR to help validate SAMG actions

o In-vessel analysis to benchmark Technical Support Guidelines (TSGs)

o Ex-vessel analysis with CORQUENCH-MELTSPREAD to help guide Severe Accident Water Management (SAWM) actions

Accident Tolerant Components

o RCIC Modeling: Develop Terry Turbo-pump dynamic model and test planning (INL RELAP7 model and SNL MELCOR model & test planning)

o RCIC Testing: Testing initiated at Texas A&M using existing facilities

Reactor Safety Technologies Reactor Safety Technologies

Evaluating component performance to potentially expand their operating range: RCIC and AFW

Reactor Safety Technologies Reactor Safety Technologies

Objectives: Develop and execute a phased test program to demonstrate extended RCIC operational envelope and validate models

o Phase 1 test program initiated 1 June 2017, and will wrap up August

2019

o Decision on whether full scale confirmatory testing is needed will be

made at that time

Motivation: Fukishima reconstruction study shows extraordinary long-term operation of RCIC over 3-day period for 1F2

Benefit to Industry:

o Expanded operating range for RCIC will provide more bridging time to

implement FLEX (PWRs have analogoud issue with AFW to

secondary side of SG);

o improvements to accident analysis codes to provide more realistic

plant safety analyses and training tools under BDBA conditions

Participation: EPRI, BWROG, PWROG, GE, IAE (Japan)

Looking forward, the LWRS Program will increase focus on reducing operating costs and plant modernization

LWRS Program Vision: Through continued operation of existing plants, power

uprates, and the addition of new LWRs, the contribution of nuclear energy to the

nations energy mix will increase during the next couple of decades.

Building on accomplishments supporting license extensions, the LWRS Program goals are transitioning from an emphasis on Subsequent License Renewal to reduced operating costs and modernization of the LWR fleet

The goals of the expanded program are:

1. Continuous improvement to support periods of extended operation of current reactors

2. Improve the reliability and economic performance of current reactors within the current and future electricity markets and energy mix

3. Improve the cost and schedule for building new LWRs to ensure they remain a viable option for meeting the nations energy needs

Concluding Remarks

LWRS focuses on LWR RD&D, leveraging national laboratory assets to support extended operations of the existing NPPs

The program coordinates closely with owner-operators and industry stakeholders to ensure RD&D is relevant and impactful

o Conduct joint research

o Coordinate on broad areas that affect long term performance and emerging issues

o feedback is actively sought

Focus has been on long-term operations

Given accomplishments related related to long-term operations, the program is increasing focus on operating costs, modernization, and, possibly, hybrid energy systems and nuclear cybersecurity

New U.S. industry-focused Funding Opportunity Announcement planned

Information on the LWRS Program is available on our website (http://lwrs.inl.gov/)

http://lwrs.inl.gov

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