Perspectives on NDE Reliability - Amazon S3 · –Ensure examiner proficiency and NDE reliability are maintained at a high level –Establish a technical basis and change management

© 2016 Electric Power Research Institute, Inc. All rights reserved.

Greg Selby

Electric Power Research Institute

NDE Technology Week 2016

Savannah

Perspectives on

NDE Reliability

2© 2016 Electric Power Research Institute, Inc. All rights reserved.

Topics

EPRI human factors research

IGSCC requalification

US initiatives correlation to BAM modular reliability model

Future research directions

Reminder of 7th European-American Workshop on Reliability of NDE (2017)

Discussion

EPRI – Electric Power Research Institute

IGSCC – Intergranular stress corrosion cracking

US – United States

BAM – Bundesanstalt für Materialforschung und –prüfung



We have defined a four-year program

– We are in the very early stages!

– Program began in 2016

– We are still figuring out what to do

Our focus

– NDE in commercial nuclear power plant (NPP) applications

– Initial focus: manual application of UT on piping welds

Our collaborator

– Part of the work will be in collaboration with the US Nuclear Regulatory

Commission (NRC) research office


Our resources EPRI human factors research

Huge reservoir of experience in laboratory NDE and performance

qualification of UT for nuclear power applications

Access

– To all the operational experience (OE)

in the US nuclear industry

– To all the players

NPP owner executives, managers and

personnel responsible for NDE

NDE companies’ executives,

managers and technicians

Regulators

Radiation management peopleNPP – nuclear power plant


We don’t have any human factors (HF)

experts in our staff

There’s some prior research available,

but not a lot that’s directly applicable

It’s hard to study

– How do you observe workers in the field,

when they are on critical path in a radiation area?

– It’s probably not practical to realistically simulate the work environment

in all its aspects

Nobody likes change

– Everyone wants more reliability, but also they are thinking

“what are you going to do to us?”

Our challenges EPRI human factors research

It’s complicated.


Engagement with our NRC collaborators

– They have HF experts!

– They have visited EPRI to see how manual UT technicians are qualified by practical examination

– They have observed manual UT as it is performed in the field

Engaged HF contractor

– A few months’ work to frame the problem

– Report due in October

– Next slides describe what they’re doing

Our initial steps EPRI human factors research

NRC – US Nuclear Regulatory Commission

HF – Human factors



2016 objective: Characterize human factors differences in manual UT between controlled laboratory and in-field environments

Developed an ‘NDE world’

– People – their functions, but also how they feel about their work and about their co-workers

Level III – the wise old expert

Level II – the experienced technician

Level I – the eager beginner

– Routines – ‘a day in the life’

– Scenarios

Routine exam, no flaws

Pressure – did we find a crack?

HF framing research EPRI human factors research



The qualification world

can be quite different

from the real world


Factor Lab Field

Fine Motor Optimal weld positioning Awkward position – overhead, for example

Gross

MotorComfortable position

Awkward and changing position; must hold tools;

personal safety

Perceptual

- Excellent lighting

- Directed attention (single focus)

- Quiet room, nice temperature

- High alertness due to new environment

and performance anxiety

- Lighting not optimal, shadows

- Distracting sounds/sights/vibrations

- Noisy factory environment

- May be hot

- Variable daily alertness/fatigue

Cognitive

- It’s a test, I know that there are many

flaws!

- I must pass to get or keep my job!

- Flaws are rare -- search fatigue

- Stress to maintain vigilance

- Time pressure – production radiation dose

Social

- Stress due to observer

- Limited communication due to testing

context

- Not observed, part of everyday job

- Social penalty for requesting help?

- Working in isolation, (maybe with headset)



Topics






Discussion







– IGSCC – intergranular stress corrosion cracking

– Has been an issue in US NPP since 1980s

– Qualification established 1983

Practical demonstration on cracked specimens

Requalification administered every three years

Near-term challenge IGSCC requalification

NP

P –

Nu

cle

ar

po

we

r p

lan

ts


Today IGSCC is much less common – it’s been detected and repaired

Industry has discovered that since the mid-1990s there really has been no regulatory commitment to perform requalification

Industry wants to replace the requalification with some other activity that will be easier and cheaper



“Qualification testing”


Both industry and regulator believe that the three-year requalification serves an

important function in maintaining the proficiency of the examiners

– For most examiners, this is the only time they see real IGSCC

The replacement activity must have equivalent (or better) proficiency

maintenance value

There are many ways to help examiners maintain their proficiency for IGSCC,

but…

How to measure it? Without a research program that costs even more than the

requalification program?

We don’t have an answer yet, but here’s the plan ...




Project Overview IGSCC requalification

A project has been launched to:

– Eliminate the current IGSCC and weld overlay requalification processes

– Ensure examiner proficiency and NDE reliability

are maintained at a high level

– Establish a technical basis and change management plan

Includes a focus group

– Provide input, direction, and oversight for the project

– Manage communications with the regulator,

utility executives, and the industry

– Determine and define the examiner proficiency benefits

provided by the current requalification process

– Ensure that any alternative process is as effective,

or is more effective IGSCC – Intergranular stress corrosion cracking


Key Activities IGSCC requalification

Review previous projects that improved examiner

proficiency

Identify all current proficiency maintenance processes

Identify gaps in the present processes

Review available virtual mockup technology

Define success

Establish a change management plan and schedule

– There may be an intermediate step, to consolidate the process for

personnel who maintain multiple qualifications

Define research necessary to support a technical basis

(expert opinion will not suffice)

Publish a final Technical Report with technical basis

Objective:

Institute a new

process for ensuring

examiner

proficiency;

eliminate

requalification

testing for

IGSCC detection,

IGSCC sizing,

Weld overlay

examination



Topics






Discussion






BAM Modular Reliability Model

Intrinsic Capability

– Physics

Application Parameters

– Application in the real

world

Human Factors

– Those humans again …

Organisational Context

– Business and

operational impacts



BAM model and NPP NDE in the US


NPP – Nuclear power plant


The US isn’t using the BAM model (yet)

But the BAM model is built on good common

sense

In any NDE environment, anywhere,

we can look at efforts to improve reliability,

and look at gaps in good reliability practice,

and map them to the BAM model

In US NPP recently many NDE reliability

improvements have been made in response to

NDE failures, and in the next slides we will

perform that mapping


Mapping to the BAM model BAM model and US NPP

Probe

verification

(receipt

inspection)

Intrinsic capability

Very little change

The techniques work

well; they simply

weren’t applied

correctly, or didn’t

match the field

condition






Plant walkdown

Simulation on

mockups

Application

Parameters

Make sure that you

really understand the

configuration

– Does it match the

NDE procedures that

you plan to apply?






Improved written procedures

Pre-job brief

Hands-on practice

Awareness of relevant OE

Proper use of team scanning

Sense of the urgency and importance of the

inspection

Human Factors

A much longer list






Effective long-term planning

Preparation far in advance

Communicating expectations to

NDE company and technicians

Selection of NDE technologies

Contingency planning

Change management

Crisis management

Organizational Context

might be the most important factor of allBAM – Bundesanstalt für Materialforschung und –prüfung




Organizational Context: BAM model and US NPP

advance planning for a reliable examination24 months

Day of exam

- Examination plan and scope

- MRP or BWRVIP guidance

- Walkdowns at N-1 outage

- Review T & Cs, procedure

options

- Procedure qualification review

- Prepare bid specification

- Vendor selection

- Detailed procedure qual

review and coverage calc

- Plan alternative techniques or

site specific quals as needed

- Scope and coverage

review with vendor

- Review plans for

alternative techniques or

site-specific quals

- Review equipment

selection & status

- Establish work plans to

support surface

conditioning, and

contingency exams

- Review qual status with

vendor

- Review status of

alternative or site-

specific quals

- Review equipment

availability & status

- Retrieve and review

previous examination data

- Obtain data analysis

software; train personnel for

data review and oversight

- Review status of:

- Procedure, alternative technique, or site-

specific qualifications

- Work plans for additional surface

conditioning and contingency

examinations

- Personnel availability, qualifications, training

- Equipment availability

- Review previous automated data for

assessment of previous conditions,

indications and contact

- Readiness

review with

vendor

- Identify

actions to

address any

issues identified

in readiness

review

- Prepare pre-job brief

- Verify:

- Procedure and personnel

qualifications

- Personnel training, availability,

contingencies

- Equipment availability,

contingencies

- Plan to perform vendor oversight

- Site support readiness

- Complete pre-

job brief

- Address any

actions resulting

from pre-job

brief

- Perform additional surface

preparation as required by

examination personnel

- Complete prompt review and

disposition of examination

results

- Perform rescans in a timely

manner as required by

examination personnel

- Implement examination

contingencies, if required

18 months 12 months 6 months

3 months 2 months 1 month 1 day

Post-exam

- Perform post-job

briefing and

document results

- Update inservice

inspection

documentation

Major themes:

Communication

Readiness reviews


More Organizational Context BAM model and US NPP

There are problems even when the NDE is done correctly

The problems arise because many people who are affected by the NDE results,

do not understand NDE processes;

this results in terrible pressures for the NDE team

“Hey, I might have found a

crack. Give us some time

to work through the

process to see if it’s real.”





NDE process: Flowchart to keep management calm

“Nondestructive Evaluation: Indication Characterization,

Evaluation, and Disposition Guideline”, 1025225 on epri.com


Organizational Context: BAM model and US NPP

Influence of the NPP owner

A good practice being adopted by some US NPP owners

– Senior managers and executives responsible for the inspection participate in the pre-job briefs

– They make sure that the examiners understand the company’s expectations

We want you to find flaws

We expect flaws and are ready to deal with them

Do not worry about any consequences

When you are done inspecting a weld, we want you to feel that you have done the best inspection you can

If you need any additional help or informationto do a better job, just ask





NDE technicians should not think that this will happen

if they find a crack or make a false call


Topics






Discussion






How is everything interconnected?

29


Many sub-systems, all interacting

Perhaps the most

complex of all


How to put the sub-systems together?

1 2

P(G)=P(1)*P(2)

P(T)=1-((1-P(1))*(1-P(2))

1

2

P(T)=P(IC)*P(AP)*P(HF) ± CP(IC, AP, HF)

IC AP HF

DP1DP2

DP3

IC AP HF2

HF1

HF3

DP1

DP2

DP3

P(T)=P(IC)*P(AP)*[1-((1-P(HF1)*(1-P(HF2))*(1-P(HF3))] ± CP(HF1, HF2, HF3)


Previous slide shows analytical probability approach

What about a random-sampling probabilistic approach?

Considering Monte Carlo analysis

– Where do we get the input distributions?

– Mostly we will have to guess

My opinion:

– We’ll never be able to fully model POD

– But the models should be able to show us where we have the most leverage

for improvement – the factors to which reliability is most sensitive


That is the state of our approach so far – it is very early!


Topics






Discussion






7th European-American Workshop

on Reliability of NDE (hosted by DGZfP and BAM)

Potsdam (near Berlin)

1½ day Tutorial: POD Basis, Advanced, Human Factors

2½ day Lectures, Posters, Discussions (Advanced Methods, Application in Industry (Focus Railway), SHM, Human and Organisational Factors)

½ day Open Space Workshop „Interconnections and Dependencies“

… YOUR [email protected]

35


Topics






Discussion






Together…Shaping the Future of Electricity

Documents

Perspectives on NDE Reliability - Amazon S3 · –Ensure examiner proficiency and NDE reliability are maintained at a high level –Establish a technical basis and change management