Risk-Oriented Methodology for Creating a 10-Year Shut-Down Interval. Risk. Application Case within the Chemical Industry

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Risk

Risk

-

-

Oriented Methodology for

Oriented Methodology for

Creating a 10

Creating a 10

-

-

Year Shut

Year Shut

-

-

Down

Down

Interval

Interval

Application Case within the Chemical

Industry

Contact:

Dr.-Ing. Robert Kauer

TÜV Industrie Service GmbH TÜV Süd Group [email protected] conventional Risk Expenditure risk-oriented

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§15 (1) Der Betreiber hat die Prüffristen der Gesamtanlage und der Anlagenteile auf der Grundlage einer sicherheitstechnischen Bewertung zu ermitteln.

The operator of a plant has to determine inspection intervals for the entire plant

and its components on the basis of a safety related assessment.

§15 (9) Bei Druckbehältern ... müssen Prüfungen von ZÜSen durchgeführt werden - innere Prüfung spätestens nach fünf Jahren und

- Festigkeitsprüfung spätestens nach zehn Jahren.

For pressure vessels ... inspections have to be performed by ZÜS organisations - internal inspections latest after 5 years

- strength tests latest after 10 years

The Situation (BetrSichV = German ISI-Code)

09/2004 internal inspection hydro-test 09/2014 internal inspection hydro-test 09/2005 5-6 weeks shut-down of the entire plant

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Creation of an inspection philosophy to

Creation of an inspection philosophy to

avoid the

avoid the

big shut

big shut

-

-

down after 5 years

down after 5 years

and run into a 10

and run into a 10

-

-

year

year

period without any shut

period without any shut

-

-

down due to inspection

down due to inspection

requirements

requirements

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The Loophole

§15 (10) Bei äußeren und inneren Prüfungen können Besichtigungen durch andere

geeignete gleichwertige Verfahren und bei Festigkeitsprüfungen die statischen Druckproben durch gleichwertige zerstörungsfreie Verfahren ersetzt werden, ....

External or internal visual inspections can be substituted by other adequate measures and regarding the strength test the hydro-test can be substituted by adequate NDT-methods, ....

§15 (17) Die zuständige Behörde kann die ... genannten Fristen im Einzelfall 1. verlängern, soweit die Sicherheit auf andere Weise gewährleistet ist, oder 2. verkürzen, soweit es der Schutz der Beschäftigten oder Dritter erfordert.

The regulator can case by case

1. extend the periods, if the safety can be guaranteed in an adequate manner 2. reduce these periods, if it is required to guarantee the safety for staff and

externals

Demands are related to the consequences for staff and public

and are related to the probability of the corresponding failure.

The Track

Definition of RISK (PoF x CoF)

Demands are related to the consequences for staff and public

and are related to the probability of the corresponding failure.

Risk-Oriented Methodology

The Process

Expert Panel / Responsibilities

Management Technical Program Documentation and Reporting Decision Making RM Process Leader Plant Team þ Process Leader þ Operator þ Inspector þ Insulation TÜV Team þ ROI engineer þ Inspector þ Material specialist þ NDT specialist

Equipment Identification

Benchmark

Plant

Hierarchy

Complexity of Analysis

Detailed

The Hierarchy

HExxxx shell side

tube side shell course compensator shell-nozzle tube bundel dished head/inlet dished head/outlet . . . leakage SHE leakage SHE leakage SHE leakage HE leakage SHE leakage SHE

Bestimmung des PoF-Wertes (trendable DM Loss of Material)

PoF for Trendable DM

on the Basis of a Usage Factor

End of Time Interval

UF

= T / RUL* FC

Usage Factor Time ( UFT)

FC RUL T UFT 1 ∗ = Determine

Usage Factor Time ( UFT)

Start 1 2 3 4 5 UFT≥ 0.4? yes no UFT≥ 0.67? yes no UFT≥ 0.9? yes no UFT≥ 1.0? yes no Determine Remnant Life RL [max; int] minT T T= Determine Time Frame T [max; int] minT T T= Determine Time Frame T Set Inspection Interval

resulting in Tint

See Degradation Documents (DD) for determining Future Allowance FA Degradation Rate DR DR FA RL=

For determining the Remnant Life, the applicability and the physical background of the method itself must be considered by using

appropriate safety margins. Evaluate Confidence in the

Previous Inspection Results

Determine Confidence Factor CF RL CF EF RUL= ∗ ∗ Determine Remnant Useful Life RUL

Determine Future Confidence FC Determine the Confidence in

the Future Extrapolation

History

Planning

Evaluate Method and Suitability of Previous Inspections Evaluate Coverage of Previous

Inspections

Evaluate Method and Suitability of Previous Inspections Evaluate Coverage of Previous

Inspections ) ; (Suitabilit y Coverage f EF = Determine Effectiveness Factor EF ) ; (Suitabilit y Coverage f EF = Determine Effectiveness Factor EF

Remnant Life =

Future Allowance

Degradation Rate

y = 5,3690E-05e6,6337E-03x R2 = 9,9620E-01 0 10 20 30 40 50 60 70 80 90 100 110 1950 1975 2000 2025 2050 2075 2100 2125 2150 2175 2200 Betriebsjahr Auslastung [%] Auslastung (P_L/(1,5xf)) [%] Auslastung ((P_L+Q)/(3xf)) [%] Exponentiell (Auslastung (P_L/(1,5xf)) [%])

Remnant Life Determination

usage

[%]

Measure Planning

Explicit measures (Interval / Methodology / Location / Scope) are planned on the basis of:

§ The information regarding risk driving systems, components, subcomponents

§ The information regarding acting damage/deterioration mechanisms, remnant

life and the confidence level achieved (regarding material, loading, and defect situation), through which adapted and adequate measures can be selected

§ The PoF-value to establish an appropriate interval

§ The risk value to adjust scope and depth of measures

I I II II III III 15 17 86 6 5 17 8 2 0 2 19 31 82 31 2 2 0 5 2 18 11 6 1 15 4

Consequence of Failure (CoF)

Probability

of

Failure

(PoF

Example HExxx: Additional testing measures

Additional testing at the inspection 2004

Tube Side:

• Liquid penetrant testing of tube sheet (inlet)

• eddy current testing of heat exchanger pipes (random sample, preferably at OD) Shell Side:

• Liquid penetrant testing of junction nozzle and vessel wall, expansion joint

• UT of vessel wall thickness on the lower part of the vessel wall and at the junction of nozzle and vessel wall

Additional testing (must be done until 2009)

Tube Side (at shutdown):

• Liquid penetrant tube sheet

• eddy current testing of heat exchanger pipes (random sample, preferably at outer diameter). If possible by testing through inlet nozzle or disassembly of heads. Shell Side

• Liquid penetrant testing of junction nozzle and vessel wall, expansion joint,

• UT of vessel wall thickness on the lower part of the vessel wall and at the junction of nozzle and vessel wall

1 2 3 4 5 T=5 T=10 0 5 10 15 20 25 30 Anzahl [-] Risikoklasse Betrachtungs-zeitraum T=5 T=10

Risk Ranking – Comparison after doing the inspection 2004

Risiko T=5 T=10 1 14 4 2 54 42 3 14 34 4 18 20 5 0 0 Anzahl Subkomponenten [%] Risk Number [-] evaluation period Number of Subcomponents with equal risk vs. risk

leakage heat exchanger and environment

-Risk

Number

Benefit

09/2004

***

non-intrusive measures

09/2014

**

09/2005

5-6 weeks shut-down of the entire plant