nrrc r&d roadmapcriteria in sfp ② establishment of realistic thermal-hydraulic evaluation...

NRRC R&D Roadmap

Nuclear Risk Research Center (NRRC)

As of February, 2019

1

R&Ds to contribute to voluntary efforts to improve nuclear safety

2. Risk Assessment Technology

1.Event assessment Technology

R&D Items

Ap

plic

atio

n

Feed

bac

k Contribute to

Feedback

① Compliance with new regulatory requirements

(e.g. additional countermeasures/modifications)

② Risk assessment

(PRA implementation)

Utilities’ efforts to improve safety

③ Risk reduction/defense-in-depth (Reinforcement measures for safety)④ Risk information Utilization in Risk Management Process

Ris

k co

mm

un

icat

ion

<Fukushima Daiichi accident / New regulatory requirements>

<Restart of NPPs>

<Stable Operation>

*炉心の著しい損傷を伴う重大事故

Stak

eho

lder

s

In-h

ou

se

2

1) Severe accident

2) Fault activity

3) Seismic motion

4) Fault displacement

5) Seismic resistance of grounds / structures

6) Seismic resistance of buildings /equipment

7) Tsunami

8) Volcano

9) Extreme weather (e.g. tornado)

10) Internal Fire/Flooding

1) PRA method (Internal/External)

2) Human reliability analysis (HRA)

3) Environmental release assessment

3. Risk Communication

<Continuous safety improvement>

⑤

*Number ①~⑤ correspond to applications in Roadmap

・Learn more about low-frequency, high-consequence natural events and develop measures to safeguard against them・Apply risk-informed technology in addition to the conventional deterministic approach

3

Level 1 Level 2 Level 3

2017 IFPRA guide2018 ～ IFPRA pilot

2019 FPRA guide /Fire modelling2020 ～ FPRA pilot

2020 Tsunami PRA procedure depending on site’s hazard level

2019 Implementation of SSHAC process2019～ Seismic PRA Model PlantImplementation of Improved hazard/fragility evaluation method (as soon as available)

2020～ High wind PRA model plant (under planning)2021～ Volcanic ash-fall PRA model plant (under planning)

Current Status of PRA method improvement

Planning R&D R&D in Progress Pilot/Model Project

Seismic PRA

Tsunami PRA

Exte

rnal

eve

nt

Other external event PRA (Tornado/ High wind/Volcano)

At Power PRA

Inte

rnal

eve

nt

Fire/Flooding PRA Note: IFPRA: Internal Flooding PRAFPRA: Fire PRAMUPRA: Multi-Unit PRA

2019 Incorporation of FCVS model into MAAP

2021 Optimized FP release estimation method

2021～ Trial Level2 PRA(Model plant)

2020 Early Radiation exposure estimation guide

2017 HRA Guide for Internal Events

2019 Peer review guide2019 MUPRA Case Study2021 Peer review implementation2021 PRA implementation guide

4

PRA ItemFiscal Year

R&D ItemBefore2017

2018 2019 2020 2021After 2022

Internal Events

Internal Event Level1 PRA Method Improvement

Human Reliability Analysis (HRA) Method Improvement

HRA Method Development for Extreme Condition

Multi-Unit PRA Method Development

Radioactive Material Release RiskAnalysis Method Improvement(Level2)

Environmental Impact Risk Analysis Method Development (Level3)

Internal Fire Internal Fire Risk Analysis Method Development (Level1)

Internal Flooding Internal Flooding Risk Analysis Method Development (Level1)

Seismic

Seismic Risk Analysis Method Improvement (Level1-2)

SSHAC Process Establishment

Hazard Analysis Method Improvement

Fragility Analysis Method Improvement

Tsunami

Tsunami Risk Analysis Method Improvement (Level1-2)

Hazard Analysis Method Improvement

Fragility Analysis Method Improvement

Tornado/High Wind Hazard/Fragility Analysis Method Improvement

Volcano Hazard/Fragility Analysis Method Improvement

Risk Communication Internal/External Communication Measures

R&D Pilot/ModelPractical

Application⇒ ⇒

Model Plant

Application of each key method as soon as become available

Projected Schedule of PRA Method Improvement

Model Plant

Model Plant

Model Plant

5

Item Gap/Solution 2017 2018 2019 2020 2021 2022～

(Regulatory Inspection System)

Support pilot project

Domestic PRA has not reached international level

↓• Establish Good PRA for

pilot plant through overseas experts review

• Develop guidance so that utilities can reflect knowledge from pilot plant

Develop PRA peer review procedure

QA of PRA has not been well-improved.

↓• Investigate associate

documents to develop peer review procedure

Develop PRA database and

PRA parameters

• High quality data for PRA yet to be collected

• ↓• Develop a Data collection

guide• Estimate generic reliability

parameters for Japanese PRAs

Study / Preparation Trial Alignment

Development of reliability data system

Examine parameter estimation methodEstimation of

generic parameters

Data collection guideTrial Use

Trial

▽data collection guide ②

▽ Reliability DB②

Data collection for the past experience

Utilities【 Remarks 】 NRRC

Data aggregation and analysis

Improvement of the reliability data system

Data collection for the operating experience,including the equipment for severe accident equipment

Peer review guide ②▽

Refine the guide

Develop peer review procedure

Review based on US PRA standard, NEI guide

Peer review Develop peer review system

Overseas experts review with Ikata unit3, Kashiwazaki-Kariwa unit 7

Guide pilot‘s findings, cooperate R&D activity and PRA standards, guidance (sequentially from level 1）

Reflect the knowledge of pilot project accordingly

PRA implementation guide②▽

1. Internal Event Level1 PRA Method Improvement▽：R&D outcome and specific area of contribution（indicated by number ①-⑤ in page 2）

Survey NEI peer review guide and establish domestic guide

Overseas Field survey of peer review

6

2. Development of Human Reliability Analysis Method

Item Gap/Solution ～2017 2018 2019 2020 2021 2022

Development /expansion

of the HRA

guide

HRA used for external events is not developed

↓• Developed HRA guide

with narrative process• HRA model for under

extreme conditions

HRA model for under extreme

conditions

HRA for External event is still to immature

↓• Developed HRA model for

each element targeting external event PRA

HRA advancement

project

Establishment of HRA that can be used for external event PRA is necessary

↓• Useful example cases,

HEP from Japanese data

New quantification method for

HRA

Quantification method reflecting context is still to immature

↓• Survey and development

of the latest method

Development of the HFE database

Lack of HFE information↓

• Database• Expand influence factors• HEP value reflect

Japanese DB trends• International

collaboration

Applications form HRA

results

Human performance improvement using HRA

↓• Survey of foreign cases• Effective reflection

Combination of qualitative

(narrative) and standard

quantification (HRA Calculator)

Extraction of tasks by HRA trial on mobile equipment(example of PWR / BWR)

Construction of DB framework

Considerate for HFE DB data spec

Reflecting Outcomes

Expansion of HRA guide, Expansion of scope of application for extreme conditions

▽ Long time, mobile equipment HRA model

▽HRA Guide ▽HRA Guide for extreme conditions (1st Ver.)

Preceding case study（SACADA, Hulex, etc.）

Survey of HEP estimation/update method

Consideration of international DB cooperation(SACADA etc.)

Investigation of actual situation - Case examples of HRA results -

Applications form HRA results

Adopt new quantification method for HRA guide

▽ Survey results

▽Survey results of foreign cases

▽Revised HRA Guide

HEP evaluation from NPP trends

Collecting data from each utility

Development of HRA analysis model under extreme conditions

- Application to tsunami PRA pilot plant - HEP update from Human Error DB

Extended application of HRA guide

Extract influence

factors

DB test drive

Development of the HRA database

▽

Develop the HRA model for the under extreme conditions

New quantification HRA method guide ▽

Reflecting Outcomes

Application

▽ Specific HRA at Tsunami PRA Model

▽：R&D outcome and specific area of contribution（indicated by number ①-⑤ in page 2）

Development of New HRA calculation code

Expansion of application examples of HRA guide by plant evaluation (Tsunami)

Survey of the latest HRA quantification method trial

7

3. Multi-unit PRA (MUPRA) ・ PRA Reliability Data Analysis


Development of multi-unit PRA (MUPRA) methodology

Standard methodology for Good MUPRA yet to be developed

↓- Development of internal

level1 MUPRA method- Development of seismic

level1 MUPRA method- Incorporation of international

knowledge of MUPRA practice

Development of reliability data analysis methodology for PRA

Japanese CCF parameters yet to be developed

↓- Collection and analysis of CCF

events- Estimation of CCF

parameters

Japanese reliability analysis of off-site power yet to be implemented

↓- Development of off-site

power reliability analysis method based on the domestic failure data of transmission lines

- Development of support system initiating event CCF analysis method

▽ CCF parameter estimation guide ②

Collection and analysis of Japanese CCF events and CCF parameter estimation

▽ CCF eventanalysis guide ②

Modeling method of CCFs in support system initiating evets▽Modeling guide ②

Reliability of off-site powers (LOOP Frequency and Non-recovery probability)

▽ Survey of the US activities▽ Estimation of LOOPnon-recovery probability ②

Seismic level1 MUPRA method ②▽

▽ Internal level1 MUPRA method ②

Expansion to level2

Elaboration of the seismic MUPRA method

(case study, etc.)

Concept of seismic level1 MUPRA method②▽

Internal level1 MUPRA method

Participation in the IAEA MUPRA Project

External (seismic) MUPRA method

Case study of a specific plant (LOOP)

Incorporation of the obtained knowledge

Elaboration of the MUPRA method

Data collection/Parameter estimation/Data update



Incorporation of the obtained knowledge

▽ Survey of the US activities


8

4. Radioactive material release risk analysis method development (Level-2)

Item Gap/Solution ～2017 2018 2019 2020 2021 2022～

Accident progression during SA

(reactor, CV, R/B)

Lack of realistic evaluation methods on containment failure, CFF and source term

↓• Understanding of the behavior

of representative FP (Cs) • Evaluation and analysis on FP

deposition/transport phenomena in CV and R/B

• Validation and enhancement of analytical models in MAAP code

• Development of realisticevaluation method on FP transport

• Development of mitigation system model (ex. FCVS)

• Establishment of realistic evaluation method on CV temperature

• Establishment of evaluation method on important accident scenario

Accident progression during SA

(Spent Fuel Pool: SFP)

Lack of validations for thermal behavior and fuel failure evaluation during SA as well as criticality evaluation in SFP

↓• Validation and enhancement of

analytical models for gas natural circulation, spray cooling, and fuel cladding failure

• Establishment of evaluation method on criticality in SFP

Application to model

plant

Evaluation method on TI-SGTR ②▽

Establishment of evaluation method on important accident scenario

Understanding of realistic FP behavior and model development (aerosol growth, FP trapping effect at CV penetration, scrubbing effect)

Fuel rupture experiments under SA conditions in SFP (Zry-4)

Fuel rupture behavior data ②▽

Proposal of simple evaluation model ②▽

Development of FCVS model

Evaluation of criticality scenario in SFP

Extraction of criticality scenario ②▽

Evaluation method on recriticality in reactor

②▽

Fuel rupture experiments under SA conditions in SFP (Zry-2)

Optimization of aerosol parameters ②▽

Understanding of code characteristics ②▽

FP deposition/transport evaluation in R/B by MAAP and validation of models

Prospects of DF in B/B ②▽Know-how for R/B modeling ②▽

FCVS model ②▽

Establishment of realistic evaluation method on CV temperature (verification of applicability of MAAP, CFD, and GOTHIC)

Verification of applicability to actual plant ②▽

Validation and enhancement of gas natural circulation model in SFPSimple flow rate

evaluation tool ②▽

Trial evaluation of level 2 PRA against model plant

Proposal of fuel rupture criteria in SFP ②▽

Establishment of realistic thermal-hydraulic evaluation method for

SFP under SA conditions

Validation of fuel behavior analysis code, development of fuel rupture criteria

Development of the method for “Good level 2 PRA” (evaluation of CFF and source term)

FP behavior model ②▽

Fuel rupture behavior data ②▽

Development of realistic evaluation

method on FP transport

Validation, modification and enhancement of analytical models in MAAP code

Validation and enhancement of SFP spray cooling model (visualizing experiments, heat transfer experiments)

MAAP input data with high accuracy ②▽


9

5. Environmental risk evaluation method Development (Level-3)


Development of the

level 3 PRA technology

Electric power industries cannot use the newest level 3PRA.

↓• Investigate the characteristic

of a U.S. code WinMACCS.• Apply to exposure

evaluation.• Development of the input

method from a MAAP to WinMACCS.

Evaluation of the level

3 PRA technology

Applicability of WinMACCS in complex terrain condition of Japan is not clear

↓• Verification by comparison

of meteorological/dispersion model and WinMACCS on complex terrain conditions.

Monitoring and

evaluation of

radioactive material

Long term migration data of radioactive material not sufficient.

↓• Fixed point monitoring of

Cesium migration.• Utilization for level 3PRA.

Investigation of WinMACCS about Emergency phase

△Input parameter improvement ②

▽Defragmentation study of Cesium ②

Investigate the influence of terrain and other important parameters

Monitoring of the environmental cesium decrease

Comprehensive analysis of parameters

Comparison, evaluation

▽ Verification of WinMACCS ②

Estimate for protective measures②▽ ▽ WinMACCS guide②

Terrain effects for cloudshine ②▽

Interface tool②▽

WinMACCS guide revise ②▽

Investigation for MAAP②▽

Analysis of parametersExperimental application

Survey of domestic parameters

Interface tool revise ②▽

Development of the input and analysis method of source term form level2


6. Development fire PRA methodology (Level-1) & Fire protection


Developmentof Fire PRA

methodology

- Not developed for internal fire PRA guide for Good PRA- Insufficiently developed fire event database and fire frequency in JapanInsufficient knowledge for seismically induced fire PRA

↓• Develop fire PRA guide based

on recent insights in the US• Develop fire frequency of

Japanese NPPs• Develop seismically induced fire

PRA methodology

Internal Fire PRA Project

Need to applicability of the guide↓

Pilot study & feed back to the guide

Fire Protection

- Need to develop countermeasures for HEAF- Need to improve method for fire propagation analysis including soot behavior for Good fire PRA

↓• HEAF tests for low voltage

cabinets**

• Develop fire propagation models

• Utilization of insights gained overseas

FPRA Guide②▽

Publish the guide②△

Insights

HEAF fire tests for electric cabinets

M/C & P/C*** HEAF tests①△

OECD international joint projects (HEAF2 and multi-compartment fire test “PRISME3”

Development of fire propagation models

Zone Model*②△ Zone Model & Field Model**②△Insights

Insights

* Zone Model with low computational load** Field Model with CFD (high computational load)*** M/C: Metal-Clad Switchgear, P/C: Power Center, MCC：Motor Control Center

Fire frequency of Japanese NPPs

Development of Internal Fire Methodology

△Fire Frequency ②

Planning of pilot study

Revision of Guide

M/C for DG and MCC*** HEAF Tests①

△

Dynamic ZOI Tests①△

△HEAF Test Report①


Trial fire PRA for a pilot plant

10

11

7. Development of internal flooding PRA (Level-1)

Items Gap /Resolution ～2017 2018 2019 2020 2021 2022

Establish Internal

Flooding PRA(IF-PRA)

methodology

- No guide for IF-PRA of Japanese NPPs- Need to accumulate insights on seismically induced IF-PRA

↓• Preparation of the

supplementing to EPRI Guide

• Develop seismically induced IF-PRA methodology

IF-PRA Project - Need to confirm technical adequacy of IF-PRA* guide prepared

↓• Trial IF-PRA for a model

plant• Identify feedbacks to IF-

PRA Guide prepared

Develop IF-PRA Methodology

IF-PRA Guide②▽

Seismic-Induced IF-PRA method

Planning of IF-PRA for a Pilot Plant

Investigate IF-PRA* method in US

Accumulate IF-PRA experience

Limiting Scope▽ Full Scope▽

Feedback to the guide

Update Guide②▽

▽ Final Evaluation


Trial IF-PRA for a pilot plant

12

Item Gap/Solution ～2017 2018 2019 2020 2021 2022~

Seismic hazard assessment

-Fault Activity-Seismic

Motion

-Uncertainty in earthquake ground motion evaluation is large-It is necessary to develop a method to realistically evaluate uncertainty in Japan

↓-Develop a method to realistically evaluate uncertainty in ground motion

Seismic PRA project

Seismicfragility

assessment

-Equipment-Buildings-Ground-Structures

Evaluation of limit bearing force and fragility is conservative

↓Develop a realistic fragility assessment method

【Equipment】

【Equipment】

【Buildings】

【Ground】

【Structures】

Formularization for PRA ②▽【Fault Activity】

8. Seismic/Earthquake Resistance 【hazard/fragility】 (Overview)

Proposal of seismic source parameter

①，②▽【Seismic Motion】

Technical support for Ikata SSHAC* project

Enhancement of key techniques/methods which constitute PSHA

Quantitative evaluation of Earthquake source parameter

Quantitative assessment index for simultaneous rupture of fault system

*SSHAC: Senior Seismic Hazard Analysis Committee


Enhance-ment of Near-source GMPE

▽Development ofadvanced PSHA②

Practical application for ground (2D) ①，②▽

Standardization (3D earthquake response analysis method) ①，② ▽

Developing realistic elasto-plastic assessment method of equipment and piping system

Developing a realistic fragility assessment technique based on the damage data

Next phaseImprovement of building behavior assessment for large input (Three-dimensional model/ground-building interaction)

Development of two-dimensional/ three-dimensional non-linear analysis

Standardization, enhancement and practical application of earthquake resistant performance verification technique for underground civil engineering structures

Developing a realistic fragility assessment method based on the damage data ①，②▽

Practical application (ultimate earthquake resistance evaluation method) ①，②▽

Developing simplified elasto-plastic assessment method of piping system ①，②△

Assessment of building behavior during large input①，②▽

Practical application for ▽natural rock mass (2D)①，②

Proposal of realistic elasto-plastic response assessment method①，②▽

Proposal of permissible values under elasto-plastic response condition ①，②▽

Step 1 Step 2

Evaluation of near-source intense seismic motion and deep subsurface structure

Development of multi-hazards evaluation

Development of fault segmentation assessment method using the new index

Deploy SSHAC process in Japan ②▽

Proposal of an interrelationship assessment index ①,②▽

Constitutive model for rock mass (3D) ①，②△

13


Assessment of seismic source by active fault

Insufficient criteria regarding fault segmentation to evaluate simultaneous rupture. Large uncertainty in regional characteristics to recognize active fault.

↓• Development of

simultaneous rupture index based on examples of fault rupture termination.

• Analysis of factors making it difficult to recognize active faults and research for their countermeasures.

Assessment of fault

properties of the recent

earthquakes

Increasing cases of surface ruptures in areas where active faults have not been recognized.

↓• Clarify possibility to pre-

identify active faults based on investigation of their fault properties.

Construction of seismic source fault assessment method considering regional uncertainty

Quantitative assessment of termination factor of seismic fault rupture

Study on possibility of pre-identification of unknown active faults before rupture

Development of recognition method for active geological structure in areas difficult to identify seismic source

Development of fault segmentation assessment method using the new index

Investigation of surface rupture not pre-recognized as active fault

Construction of surface rupture survey method using remote sensing data

Distribution pattern

8-1. Seismic/Earthquake Resistance【Fault Activity】▽：R&D outcome and specific area of contribution（indicated by number ①-⑤ in page 2）

Properties of fracture zone, and fault activity

Comprehensive evaluation method①△

Simultaneous rupture index ①，②▽ Formulation for PRA②▽

Recognition method in volcanic areas ①▽

Recognition method in immatureareas of active fault① ▽

Incorporate findings



Comprehensive evaluation method based on the newly found fault properties

Extraction of new properties in the recent earthquakes ①▽

14

8-2. Seismic/Earthquake Resistance 【Seismic motion】


Evaluation of seismic ground

motion by identifying the seismic source

Seismic source model is lacking qualitatively and quantitatively. Improvement of velocity structure model for deep underground is required too.

↓• Source modeling using

integrated technique• Deep subsurface

structure modeling based on observational data

Evaluation of seismic ground

motion with unspecified

source

The causes of high-acceleration ground motions exceptionally observed at middle scale M6-class earthquakes are not fully understood.

↓• Elucidation of the causes

based on in-situ surveys. • Evaluation of basement

motions during M6-class earthquakes excluding amplification factors.

Probabilistic SeismicHazard

Analysis (PSHA)

A method to apply SSHAC-based PSHA in Japan has been not developed

↓• Develop SSHAC level 3

methodology applicable to Japan: to evaluate epistemic uncertainties in PSHA

• Enhance key techniques/methods that constitute PSHA

Quantitative estimation of seismic source parameters based on inversion technique

Systematization of methodology for subsurface structure modeling ①▽

Systematization of the modeling technique for the underground structures based on earthquake and micro-tremor observation

Regarding high-acceleration ground motions data by NIED*

①Elucidation of causes and evaluation of ground

motions based on in-situ subsurface structure surveys②Verification by borehole array observations（Joint

research with NIED）

Nonlinear/topographic/3D site effect model ①②▽

Evaluation of near-source intense seismic motion and deep subsurface structure

Construction of site effect model and its application to ground motion prediction equations (GMPE)

Evaluation of the characteristics of seismicground motion with unspecified source ①▽

Incorporate into uncertainty evaluation


Analysis of common and site-specific characteristics from near-source seismic records to provide new findings① ▽

Source parameters of historical and recent earthquakes in Japan ①②▽

Technical support of Ikata SSHAC Project Deployment of SSHAC-based PSHA to other sites/Development of multi-hazards evaluation (superposed seismic and tsunami)

Enhancement of key techniques/methods which constitute PSHA (Phase 1)

△Draft the project plan②

Support of drafting the project final report②▽

△Enhancement of method to select ground motion prediction models quantitatively②

Identify and analyze gaps to implement SSHAC Level 3-based PSHA②▽

△Development of PSHA that employs both GMPE and fault rupture model②IAEA TECDOC：Development of PSHA testing and upgrading method

▽Deploy SSHAC process in Japan②


*NIED: National Research Institute for Earth Science and Disaster Resilience

Enhance-ment of Near-source GMPE

Modeling of Diffuse seismicity evalua-tion

Enhancement of PSHA Method


Incorporate PSHA

Enhancement of key techniques/methods which constitute PSHA (Phase 2)

15

8-3. Seismic/Earthquake Resistance 【Equipment】


Shaking test of equipment and

piping

Insufficient data on limit bearing force and function maintenance of equipment and piping against higher acceleration.

↓To evaluate a realistic capacity using the 20G resonance shaking table.

Realistic capacity/response

assessment of equipment and

piping

Current evaluation of limit bearing force and fragility is conservative.Lack of fragility assessment method of equipment including mobile equipment.

↓Developing realistic evaluation method based on plastic deformation capacity/fatigue/elasto-plastic response.Developing fragility assessment method of the target equipment such as mobile equipment.

Valve shaking test/marginal valuation of function maintenance

・Evaluation of realistic capacity of equipment and piping by shaking test・Developing and standardizing a realistic response assessment method for equipment and piping taking

elasto-plasticity into account・Development of simplified elasto-plasticity evaluation method of piping

・Improving the equipment fragility assessment based on safety factor method・Developing fragility assessment method of equipment newly covered by new regulatory requirements・Developing a realistic fragility assessment technique based on the damage data

Marginal valuation of function maintenance of valves①，②▽

▽ Proposal of permissible values under elasto-plastic response condition ①，②

▽Realistic fragility assessment method based on the damage data①，②

Proposal of realistic elasto-plastic response assessment method①，②▽

Improvement of the permissible values/seismic motion index/improving the cumulative fatigue assessment according to the damage mode for each type of equipment

Proposal of a fatigue damage assessment method for multi-

dimensional seismic input①，②▽

Realistic seismic evaluation method of equipment and piping①▽

▽ Developing realistic marginal valuation method of function maintenance①，②

Improved safety factor evaluation method/fragility assessment method of mobile equipment①，②▽

Developing simplified elasto-plasticevaluation method①，②▽

Development of realistic seismic evaluation method taking the new nuclear regulatory requirements into account




Development of seismic evaluation method taking high-frequency seismic loading or combination of three dimensional seismic motion into account

Seismic evaluation method with consideration of high-frequency seismic loading or combination of

three dimensional seismic motion①▽

Rationalization of seismic design of heat-transfer pipes in steam generator

Improved seismic designmethod of heat-transfer

pipes in steam generator①▽

Improving fragility assessment method of piping

Fragility evaluation method of piping taking elasto-plastic response into account ①，②▽

△Standard proposal of elasto-plasticity evaluation method①，②

△Improved elasto-plasticity evaluation method①，②

16

8-4. Seismic/Earthquake Resistance 【Buildings】


Rational seismic design technique and seismic safety

assessment technique

Insufficient knowledge of three-dimensional vibration characteristics in case of ultimate seismic input and the decrease in stiffness of reinforced concrete after the earthquake.

↓Developing evaluation and identification method of vibration characteristics using three-dimensional FEM analysis of buildings.Developing Seismic load assessment method taking into account the decreases in stiffness after the earthquake.

Limit load design

method for the seismic

isolation structures

Current design limit of seismic isolation buildings is within linear range.

↓Developing seismic isolation design method exceeding the linear limit.

Development of seismic isolation design method exceeding the linear limit

Seismic isolation design method exceeding△the linear limit①、②

Development of an identification method for three-dimensional vibration characteristics based on the seismic observation of actual buildings

High acceleration testing method for reinforced△concrete①，②

△Assessment of building behavior during large input, impact assessment technique①，②

Seismic load assessment taking into account the decrease in stiffness after the earthquake①，②▽

Assessment of three-dimensional response characteristics of buildings①，②▽

Improvement in building behavior assessment for large input (Three-dimensional model/ground-building interaction)

Next phase: Developing a fragility assessment technique for seismic isolation buildings

Next phase: Research for advanced seismic safety assessment



△Proposal of 3D earthquake resistance evaluation method①，②


Redundant safety management for seismic isolation system①、②▽

Next phase:Peripheral technology for seismic evaluation on exiting reactor buildings

Incorporatefindings

Development of a seismic load assessment method taking past earthquakes into account

17

8-5. Seismic/Earthquake Resistance 【Ground and Structures】

Items GAP/Solution ～2017 2018 2019 2020 2021 2022～

Assessment of ground and

slopes

• Increase of design–basis seismic motion caused the difficulty to assess ground and slopes by 2D non-linear analysis method.Need to develop more realistic analysis method and rational risk assessment

↓• Practical application of

2D/3D nonlinear analysis • Risk assessment by

Nonlinear /Discontinuumanalysis

• Development of the rational prediction method of liquefaction

Assessment of civil

engineering structures

・Increase of design-basis seismic motion and difficulty in current conservative seismic verification method・Need for realistic analysis technique and rational verification index

↓・3D nonlinear analysis and deformation/strain index for ground structures・Seismic resistance evaluation considering detailed damage mechanism, equipment boundary and maintenance effect etc.

Next Phase

Additional enhancement of verification techniques etc.

Formulation of seismic resistance verification techniques①，②▽

Three-dimensional non-linear analysis

Practical application for ground ①, ② ▽

Constitutive model for rock mass ①，②▽

Risk assessment of slopes and ground

Two-dimensional non-linear analysis

3D non-linear seismic analysis of ground structures / Benchmark experiment for 3D deformation/strain index

Standardization, enhancement and practical application of earthquake resistant performance verification on underground civil engineering structures

Experimental, numerical analysis for the damage mechanism of steel reinforced concrete structures

3D non-linear seismic response analysis of ground structure interaction system/Study related to the deformation/strain index

・Detailed bearing force assessment of structures and

equipment boundary・Study of maintenance effect against weathering

Standardization (three-dimensional earthquake response analysis method) ①，②▽

Practical application (ultimate earthquake resistance evaluation method) ①，②

▽

Development of the rational prediction method of liquefaction

Practical application for natural rock mass ①，②

▽

PRA manual②▽Rational evaluation method for

rock mass properties ②▽

Slope failure evaluation method by discontinuum analysis①，②▽

Prediction method of liquefaction①，②▽


Practical application of Three dimensional non-linear analysis

Rational evaluation method of variability of ground mechanical properties

Risk assessmentconsidering coupling structure and ground

3D slip safety factor evaluation method ①,②▽

18


Fault activity assessment

based on fracture zone in basement

rock

It is difficult to assess fault activity when the age of overlying strata is unknown or it is absent.

↓• Development of

assessment method of fault activity based on fracture zone properties.

• Development of a dating method which is applicable to the strata unmeasurable by traditional methods.

Comparative investigation and analysis of active faults and inactive faults, and systematization of survey/evaluation method

Analysis of the detailed structure and composite material of the fault fracture zone

Field survey of (active/inactive) fault fracture zones

Development of a new dating method

Set-up of fault deformation experiment ①，②△

Reproducing the fault fracture process and verifying the index through lab experiments

Sample preparation method of fault rocks ①，②▽

9-1. Assessment of Fault Activity under NPP【Identification of active fault】


Geological samples

Incorporate findingsComparison &validation Quantitative evaluation criteria of

fault fracture zone ①，②▽

Systematization of assessment techniques ①，②▽


New dating method ①，②△

Activity assessment techniques based on fault fracture properties ①，②▽

Introduction of dating equipment and dating method ①，②△

19

9-2. Assessment of Fault Activity under NPP 【Assessment of Fault Displacement】


FaultDisplacement

Evaluation

There is no practical method that can predict fault displacement quantitatively. Besides, there are few field data.

↓Construction of database utilizing remote sensing data.Establishment of methodology of numerical simulation.

There is no practical assessment method of design regarding fault displacement including tolerable value for building

↓Study on assessment method including response analysis method and capacity evaluation by numerical simulations and experiments

There is no practical method regarding fault displacement PRA for quantitative risk assessment

↓Study on fragility evaluation method and accident sequence to establish PRA methodology

Construction of fault displacement database utilizing remote sensing data

▽Fault displacement hazard assessment technique②

Input parameter

▽Superposition with seismic motion①，②

Establishment of fragility evaluation method for buildings, structures, equipment and piping.Establishment of PRA method by conducting accident sequence evaluation

▽Superposition with seismic motion①，②

▽Superposition with seismic motion②

Proposal of PRA method②▽


Improvement of Empirical equation

Construction ground deformation DB around damaged structures by faulting

Establishment of assessment method for civil engineering structures

Establishment of dynamic fault rupture model/Utilization of HPC

Proposal of assessment method①，②▽

Superposition of displacement and seismic motion

Establishment of assessment method for reactor building （phase 2)

Proposal of damage assessment method ①，②▽Superposition with seismic motion①，②▽

（phase 3)

(phase 2)

Improvement of existing PFDHA method(Probabilistic Fault Displacement Hazard Analysis)

Development of identification method regarding primary/secondary fault

Construction ground deformation DB around damaged structures by faulting

Validation

(Proposal based on results of phase2)

20

10. Tsunami 【hazard /fragility】


Tsunami hazard

assessment

• Due to few reliable records on paleo tsunami, uncertainty of paleo tsunami flooding estimation is large.

• Non-seismic tsunami evaluation method is not yet developed.

↓• Increase geological

knowledge and quantify the uncertainty of tsunami evaluation more accurately.

• Establish probabilistic non-seismic tsunami risk assessment method

Tsunami PRA project

Tsunami fragility

assessment

• Lack of knowledge for fragility evaluation method considering various tsunami effects in tsunami PRA

• It is necessary to verify new method on tsunami impact assessment.

↓• Proposal of procedure

for fragility evaluation in tsunami PRA

• Collection of new findings and development of the tsunami impact assessment method

Analysis of tsunami deposits on the site, experiments of tsunami deposits creation process, and establishment of an assessment procedure

Development of numerical analysis method for non-seismic tsunamis (submarine and subaerial land slides, volcano.)

Development of probabilistic hazard assessment method for non-seismic tsunami

▽ Tsunami flooding scale evaluation technique based on analysis of tsunami deposits ①，②

△ Tsunami PRA procedure depending on site’s hazard level ②

Development of tsunami impact assessment (overflow/wave pressure/debris impact/suspended sediment impact)

△ Tsunami debris impact evaluation method ①，②

Preliminary evaluation Detailed evaluation

A trial on a method linking hazard assessment and fragility evaluation in tsunami PRA

△ Concept of graded approach depending on site’s hazard level ②

△ Suspended sediment impact evaluation method for ECCS** ①，②

Evaluation method for overflow through CCWS*▽①，②

Wave pressure evaluation method for structure▽①，②

Extension of probabilistic tsunami hazard assessment method considering non-seismic sources

▽Primary method for probabilistic non-seismic tsunami hazard assessment①

Development of Tsunami flooding scale evaluation technique on analysis of event deposits

Evaluation method for debris impact of▽ small vessels①,②

Development of numerical analysis method for non-seismic tsunamis (submarine and subaerial land slides)

▽Evaluation method of tsunami due to caldera generation①②


Improvement of design method for piping and equipment against tsunami inundation flow▽①，②

*CCWS: Component Cooling Water System, **ECCS: Emergency Core Cooling System

▽Application to the actual site ③,④

△ Tsunami flooding scale evaluation technique based on analysis of event deposits ①，②

▽Probabilistic Tsunami hazard assessment method considering seismic and non-seismic sources ②

11. Extreme Weather such as Tornadoes 【hazard/fragility】


Extreme weatherhazard

assessment,tornado missile

impact assessment

Lack of rational assessment methods for typhoon/tornado hazards including effect of topographic/regional conditions on tornado characteristics, tornado missile strike probability suitable for Japanese conditions

↓・Typhoon/tornado hazard assessments considering topographic and weather conditions・ Probabilistic tornado missile assessment・Fluctuational local wind assessment

High wind PRA project

Assessment of counter-

measures to extreme

weather, and technology to

support lashing (tying-down)

measures

Lack of quantitative risk evaluation methods, rational design method for adequate countermeasures for tornado missile

↓・Rationaldesign method

for tornado missile countermeasuresbased on fragility and risk evaluation・Tornado detection

and prediction methods for flexible operation of lashing measures

Improvement & update of tornado hazard model, TOWLAImproving tornado missile hazard model, TONBOS

Collection of back data & establishing numerical methods for high-strength wire net protection as well as structural penetration resistance

▽ Rational countermeasures for tornado missile and rational assessment method ①

Development a probabilistic tornado missile strike assessment code, TOMAXI

▽ Tornado hazard assessment method applicable to Japanese sites ①，②

Development of typhoon hazard model and impact evaluation method

Establishment of a real-time tornado detection and prediction system based on weather radar data

▽ Method to flexible operation of lashing measures ①

Development of high-wind risk detection and prediction tool with real site application

Development of evaluation method for local fluctuational wind in an NPP site


Development of tornado risk evaluation method for Japanese enhanced Fujita scale

Under planning

Development of design methods for countermeasure based on risk information

▽ Probabilistic tornado missile strike assessment technique ②

Typhoon hazard assessment method ①，②▽

21

22

12. Volcano 【 Hazard/fragility】


Hazard analysis of

volcanicash-fall

Current ash-fall load hazard assessment is in deterministic approach. Estimation of accurate initial condition is essential to improve the numerical analysis of ash-cloud dispersion.

↓

- Develop literature-based ash-fall hazard curve.- Estimate accurate

initial condition for numerical analysis of ash-cloud.

Volcanicash-fall PRA

project

Vulnerability assessment to

volcanicash-fall

Fragility data on the effect of ash-fall to facility and efficient counter-measures for filter systems are lacking.

↓

- Conduct tests for air intake facility.

- Develop ash separation system.


Development of literature-based hazard curve

▽ Pre-filter for volcanic ash ① ▽ Gravitational separation system ①

Development and verification of an assessment model connecting magma and ash-fall characteristics.

Development of ash-cloud altitude assessment tool (Merge ash-plume and ash-cloud dispersion models)

Improvement of volcanic ash-fall database (age, distribution).▽Literature-based hazard curve ②

Improvement of hazard curve

Development of pre-filters for volcanic ash-fall.

Experiment and numerical analysis on the amount of ash that enter the air intake system of DG.

Experiment and numerical analysis of gravitational ash separation system.

▽Improved hazard curve ②

Under planning

Conduct tests as necessary

Incorporating distribution of wind direction.Selection of representative wind condition.

Large-scale eruption (numeri-cal, geology)

Selection of representative grain-size distribution.

Grain-size distribution ②▽

Wind direction②▽

Application / feedback

Application / feedback

23

13. Risk communication (RC)


Investigation of internal and

external RC in electric power

company

RC activities in Risk Management (RM) thatstill has room for improvement.

↓• Proposal of RC

measures in RM

Study on how to

communicate with local

communities

Effective RC measures through the establishment of Urgent Protective action planning Zone (UPZ) have not been established.(Expansion of scope regarding RC)

↓• Proposal of RC

measures to contribute to acquisition of trust from Site/ Neighboring area/ UPZ

• Proposal of RC measures based on the public information needs and a cause of approval attitudes regarding nuclear energy.

• Accumulation of good example.

Research on RC measures in voluntary efforts andimprovement for nuclear safety

Experimental survey of RC measures based on the practical site needs and accumulation of good example

Solving medium to long-term issues

Goodexample▽⑤

▽ Bidirectional RC measuresas a PRA theme ⑤

▽ RC measures in RM(Knowledge and tools) ⑤

Good examples in foreign countries⑤▽

Good examples in foreign countries⑤▽


nrrc r&d roadmapcriteria in sfp ② establishment of realistic thermal-hydraulic evaluation...

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