Redesigning inspection process upon repairs at Tronox Pigments B.V

Specialization:

Production Engineering and Logistics

Report number: 2013.TEL.7746

Title:

Redesigning inspection process

upon repairs at Tronox Pigments

B.V.

Delft University of Technology Department Maritime and Transport Technology Mekelweg 2 2628 CD Delft the Netherlands Phone +31 (0)15-2782889 Fax +31 (0)15-2781397 www.mtt.tudelft.nl

This report consists of ## pages and # appendices. It may only be reproduced literally and as a whole. For commercial purposes only with written authorization of Delft University of Technology. Requests for consult are only taken into consideration under the condition that the applicant denies all legal rights on liabilities concerning the contents of the advice.

Specialization:

Production Engineering and Logistics

Report number: 2013.TEL.7746

Title:

Redesigning inspection process

upon repairs at Tronox Pigments

B.V.

Author:

E.P. van Os

Title (in Dutch) Herontwerp van het inspectie en reparatieproces bij Tronox Pigments B.V.

Assignment: Masters thesis

Confidential: yes (until March 01, 2018) Initiator (university): prof.dr.ir. G. Lodewijks

Initiator (company): P. Kats MSc (Tronox Pigments BV) Supervisor: dr.ir. H.P.M. Veeke

Delft University of Technology Department of Marine and Transport Technology Mekelweg 2 2628 CD Delft the Netherlands Phone +31 (0)15-2782889 Fax +31 (0)15-2781397 www.mtt.tudelft.nl

Student: E.P. van Os BSc Assignment type: Master thesis

Supervisor (TUD): Dr.ir. H.P.M. Veeke Creditpoints (EC): 35 Supervisor (Tronox

Pigments)

P. Kats MSc. Specialization: PEL

Report number: 2013.TL.7746 Confidential: Yes

until March 01, 2018

Subject: Redesigning inspection process upon repairs at Tronox Pigments B.V. I Introduction

Tronox Pigments B.V., located in Botlek, the Netherlands, is a producer of titan dioxide (TiO2)

pigment. The plant consists of a large collection of static pressure equipment (e.g. vessels and boilers) and piping, subject to (statutory) inspections upon (temporary) repair or modification. Test and inspection plans need to be drawn up before a (temporary) repair or modification is conducted. These plans indicate how a (temporary) repair or modification is to be conducted and which inspections need to happen during or after repair or modification. Test and inspection plans need to be obeyed,

returned after completion and reviewed. In specific cases an external supervisor is to be involved. Furthermore, due to the presence of large amounts of chemicals such as chlorine, the factory is subject to legislation demanding a controlled execution of all operations, including maintenance and inspections.

II Problem statement

An investigation of the inspections concerning (temporary) repairs revealed a situation incompliant with the prevalent legislation and compromising safety:

• The control system governing the inspection fails. Test and inspection plans remain unreturned and therefore unreviewed.

• The involvement of the external supervisor is not executed according to law, specifically the supervision is executed in hindsight

Ad1. Reasons are identified to be the lack of a measurement and control system, lack of intrinsic interest combined with lack of (enforced) incentives.

Ad 2. Reasons are identified to be the pressure to minimize downtime, combined with an external supervisor allowing the situation to pertain.

Delft University of Technology Department of Marine and Transport Technology Mekelweg 2 2628 CD Delft the Netherlands Phone +31 (0)15-2782889 Fax +31 (0)15-2781397 www.mtt.tudelft.nl

III Assignment description

Redesign processes pertaining to test and inspections concerning (temporary) repairs and modifications.

IV Execution

• Identify all functional and legal requirements of the repair- and inspection process • Establish the necessary functions present in the process

• Establish a control system of said process

• Define the roles and responsibilities of actors in the process execution and control • Identify the means (tools) to be used

• Quantify the cost and benefits inflicted by the redesigned process

• Motivate how the redesigned process will be adhered to in practice, and thus will meet requirements and solve deficiencies identified earlier, specifically with respect to legal compliance and safety

• Study relevant literature

A detailed implementation plan is not part of the execution.

The report should comply with the guidelines of the section. Details can be found on the website.

Supervisor

Professor

Table of Contents

1. Introduction ... 1

1.1

Tronox ... 1

1.2

Titanium dioxide TiO

... 1

1.3

TiO

production at Tronox Botlek ... 1

1.4

Safety and environment ... 2

1.5

Legislation and supervision ... 2

1.5.1

Legislation and safety... 3

1.5.2

Supervision ... 4

1.6

Repair and inspection ... 5

1.7

Problem statement and initial research question ... 7

2. Current inspection regime at Tronox Botlek ... 8

2.1

Safety control system: KPMS ... 8

2.2

Software system ... 9

2.3

Equipment ... 9

2.3.1

Piping ... 9

2.3.2

Equipment ... 9

2.3.3

Statutory inspection regime vs. duty of care ... 10

2.4

Summary of statutory inspection regime ... 10

2.4.1

Inspection upon first commissioning of new equipment ... 11

2.4.2

Periodic Inspections ... 11

2.4.3

Inspections upon repair or modification ... 11

3. Analysis of repair and inspection process... 12

3.1

Introduction ... 12

3.2

Operating instruction ... 13

3.3

General observations on KEs ... 14

3.3.1

Large or small operation ... 14

3.3.2

Timescale ... 14

3.3.3

Work order ... 14

3.3.4

Hold points and witness points ... 15

3.3.6

Quality norms ... 15

3.3.7

Paper form ... 15

3.4

Systemic representation of the KE process... 16

3.4.1

Control system ... 18

3.4.2

Commissioning ... 18

3.5

Quantitative analysis of KE process ... 18

3.6

AKI involvement ... 21

3.7

Relation between deficiencies and safety ... 22

3.7.1

Compromise to safety due to unreturned KEs ... 22

3.7.2

HP registration ... 23

3.7.3

Safety compromise due to AKI involvement in hindsight ... 24

3.8

Incompliance due to deficiencies ... 24

3.9

Causes of deficiencies ... 25

3.9.1

Cause: KEs are not returned for review ... 25

3.9.2

Cause: AKI involvement is executed in hindsight ... 25

3.9.3

Cause: Registration of hold point execution is lacking ... 25

3.10

Conclusion ... 26

3.11 Supplementary deficiencies ... 26

4. Temporary repairs ... 27

4.1

Introduction ... 27

4.2

Procedure ... 27

4.3

General observations on TReps ... 29

4.3.1

Large or small operation ... 29

4.3.2

Timescale ... 29

4.3.3

Emergency repairs ... 29

4.3.4

Equipment governed ... 29

4.3.5

KE ... 29

4.4

Systemic representation of TRep process ... 29

4.4.1

Control system ... 31

4.4.2

Commissioning ... 31

4.5

Quantitative analysis of TRep process ... 31

4.6

Inspectorate and AKI involvement ... 33

4.7.1

TRep forms remain unreturned ... 34

4.7.2

Not involving inspectorate or AKI ... 35

4.7.3

Extension ... 35

4.8

Incompliance due to deficiencies ... 36

4.9

Causes of deficiencies ... 36

4.9.1

Causes: Unreturned TRep forms ... 36

4.9.2

Causes: Inspectorate/AKI involvement in hindsight ... 36

4.10

Interrelation KE and TReps ... 37

4.10.1 Determining the workload for the inspectorate and AKI ... 37

4.10.2 Historical data analysis ... 39

4.11 Conclusion ... 39

5. Final research question ... 40

6. User inspectorate IVG ... 42

6.1

Cost and yields ... 42

6.2

Flexibility ... 45

6.3

Periodic inspections ... 45

6.4

Safety... 46

6.5

Gap analysis ... 46

6.6

Decision ... 46

7. Redesign of repair and inspection process ... 47

7.1

Introduction ... 47

7.1.1

Research question ... 47

7.1.2

System boundary ... 48

7.1.3

Method ... 49

7.1.4

Other (Tronox) plants ... 50

7.2

Requirements ... 51

7.3

Functional design of repair and inspection process ... 52

7.3.1

Establishing contents and structure of functional design ... 52

7.3.2

Sequential dependencies ... 53

7.3.3

Continuity of process ... 56

7.3.4

Conclusion functional design ... 57

7.4

Proposal control design ... 58

7.4.2

Control design ... 59

7.4.3

Conclusion on control system ... 60

7.4.4

Scenarios ... 61

7.5

Proposal practical implementation ... 64

7.5.1

Functional streams ... 65

7.5.2

Practical details on control system ... 67

7.5.3

Procedure ... 68

7.5.4

AKI involvement ... 68

7.5.5

Repairs and modifications not inspected by IVG ... 68

7.5.6

Intervention and sanctioning ... 69

7.6

Incorporating temporary repairs ... 70

7.6.1

Integrating KE and TReps ... 70

7.6.2

Temporary repair on equipment on VL53.003 ... 70

7.6.3

Temporary repairs on equipment outside inspection regime ... 71

7.6.4

Emergency repair ... 71

7.7

Theory of system behavior ... 72

7.7.1

Theory of violations ... 72

7.7.2

Theory of IT use and acceptance ... 73

7.7.3

Parallels in compliance theory and theory on use of IT ... 75

7.8

Transposing theory on redesign ... 77

7.8.1

Current incompliance at Tronox ... 78

7.8.2

Culture ... 78

7.8.3

System behavior of redesign... 80

7.9

Conclusion on redesign... 87

7.9.1

Meeting requirements ... 87

7.9.2

Adherence to theory on compliance ... 87

7.9.3

Extant risks ... 88

8. Conclusion... 91

References ... 94

Appendix A – Research paper ... 97

APPENDIX B - Tronox titanium dioxide production ... 104

1. Tronox ... 104

1.2

Locations ... 105

1.2.1

Former locations ... 105

1.2.2

Current operations ... 105

1.3

Titanium dioxide TiO

... 107

1.4

TiO

Production in detail ... 108

1.5

TiO

Production at Tronox Botlek ... 110

1.5.1

Input ... 110

1.5.2

Throughput ... 111

1.5.3

Output ... 111

1.5.4

Capacity ... 111

1.6

Operations at Tronox Botlek ... 113

1.6.1

General ... 113

1.6.2

Production ... 114

1.6.3

Maintenance ... 114

1.6.4

Plant stops ... 115

1.6.5

Project engineering ... 115

1.6.6

Maintenance engineering ... 115

1.6.7

Inspection ... 115

APPENDIX C - Study on Legislation ... 117

1. Legal requirements on safety ... 117

1.1

Permit ... 118

1.2

Wabo ... 118

1.3

BRZO ... 118

1.3.1

Safety Control system VBS ... 121

1.3.2

BRZO supervision ... 122

1.4

Additional legislation ... 137

1.4.1

BEVI ... 137

1.4.2

Fire brigade ... 137

1.5

Future developments on safety, supervision and legislation ... 137

1.5.1

Incidents... 138

1.5.2

Media coverage and political reaction ... 139

1.5.3

Problems with supervision ... 142

1.6

Compliance and safety ... 149

2. Law governing the use of pressurized equipment ... 152

2.1

History of pressurized equipment and legislation ... 152

2.2

Current law regarding pressure equipment ... 153

2.2.1

Construction of pressure equipment ... 153

2.2.2

Operation phase ... 157

2.3

Inspections during lifetime of equipment ... 160

2.3.1

Assembly ... 161

2.3.2

Putting into use (commissioning) ... 161

2.3.3

Operation phase ... 161

2.4

Statutory inspection regime under AKI supervision ... 162

2.4.1

Inspection upon Comissioning KvI: VvI ... 162

2.4.2

Periodic inspection ... 164

2.4.3

Inspection following repairs ... 166

2.4.4

Inspection upon secondary commissioning ... 166

2.5

User inspectorate ... 167

2.5.1

History of user inspectorates. ... 167

2.5.2

Criteria on IVG ... 168

2.5.3

Scope of certification. ... 169

2.5.4

Supervision on IVG ... 170

2.5.5

Certification ... 170

2.6

IVG regime ... 170

2.6.1

Periodic inspection (fixed interval) ... 171

2.6.2

Periodic inspection (extended interval) ... 171

2.6.3

Periodic inspection (flexible interval) ... 172

2.6.4

Inspections – Structural Alterations ... 172

2.6.5

Inspection - Repairs ... 173

2.7

Future legislation ... 173

APPENDIX D - Equipment and Piping ... 174

Equipment and piping ... 174

Pressure equipment ... 174

Piping ... 176

1. Quantitative analysis of in and output of KE process ... 178

1.1

Amount of KEs issued annually ... 178

1.2

Analyzing in- and output ... 178

2. Zooming in on KE process quantitatively... 184

2.1

Locating the discrepancy of unreturned KEs ... 185

2.2

Work in Progress and buffer ... 186

2.2.1

Backlog ... 186

2.3

Intermediate conclusion ... 187

2.4

Specifying the discrepancy ... 188

2.4.1

Contractors ... 189

2.4.2

Other factors ... 190

APPENDIX F - AKI involvement ... 191

1. AKI involvement ... 191

Analysis of dates on KE forms ... 191

AKI involvement: Approval of KE in hindsight ... 193

Unreturned KEs pertaining to statutory inspections ... 193

AKI role ... 194

APPENDIX G - Safety and deficiencies... 196

1. Compromise to safety due to deficiencies in KE process ... 196

Compromise on safety due to unreturned KEs ... 196

Commissioning ... 198

Compromise to safety due to AKI involvement in hindsight... 200

APPENDIX H - Legal compliance and deficiencies ... 200

1. Incompliance due to deficiencies in KE process... 200

APPENDIX I - Causes of deficiencies ... 201

1. Causes for deficiencies ... 201

KEs are not returned for review ... 202

Cause 1 No measuring system ... 202

Cause 2 No ownership materializing ... 203

Cause 3 Lack of incentive or dependencies ... 203

Cause 4 Suppliers are aware of lack of control ... 204

Capacity and availability... 206

HP execution not traceable ... 209

APPENDIX J - Analysis of TRep implementation ... 210

1. Frequency of TReps ... 210

Quantitative analysis of TRep process ... 213

Input output ... 213

SAP work order ... 213

Paper TRep forms ... 214

Discrepancy between work orders in SAP and paper forms ... 214

Extension of validity dates... 216

AKI involvement ... 216

APPENDIX K - Study on cost and yield of IVG status ... 218

1. IVG user inspectorate ... 218

1.1

Compliant without IVG status... 220

1.1.1

Approach ... 221

1.1.2

Analysis TReps and AKI involvement ... 231

1.1.3

Analysis of KEs ... 233

1.1.4

Nature of KE and TRep ... 233

1.1.5

Other costs ... 234

1.1.6

Conclusion: Compliant without IVG ... 235

1.2

Compliant with IVG ... 236

1.2.1

Yields offered by IVG status ... 237

1.2.2

Costs offered by IVG status... 244

1.2.3

Conclusion Compliant with IVG ... 247

1.3

Comparison IVG and non-IVG ... 248

1.4

Safety... 249

1.4.1

IVG and factor F1, Problem P1 ... 250

1.4.2

IVG and factor F2, Problem F2 ... 250

1.4.3

Conclusion on safety ... 253

1.5

Gap between current situation and IVG ... 254

1.5.1

Personnel requirements ... 254

1.5.2

Procedures ... 254

1.5.3

Organizational requirements ... 255

APPENDIX L - Inventorying of requirements on redesign ... 257

1. Requirements ... 257

1.1

Vision and policy ... 257

Policy declaration SHE ... 258

KPMS Quality Management system ... 259

KPMS ISO9001 Quality handbook ... 259

PBZO Prevention policy document ... 260

Risk assessment matrix ... 260

Conclusion: Requirements from policy/vision ... 261

Future policy ... 262

1.2

Goal and function ... 262

Goal and function ... 262

What is left out of consideration ... 264

1.3

Deficiencies in current design ... 266

Hiatus H1 KEs are not returned for review... 267

Hiatus H2 AKI approval is executed in hindsight... 267

Hiatus H3 Registration of hold points is lacking ... 268

Additional hiatus: no verification of hold points before commissioning ... 268

Temporary repairs ... 270

Conclusions: requirements from deficiencies ... 271

1.4

Legal outline ... 272

Functions ... 274

Streams ... 276

Buffer 276

Actors 277

Norms 277

Other (Control) ... 278

Conclusion: Requirements from legal outline ... 278

1.5

Boundary conditions ... 278

KPMS 278

SAP

279

Conclusion: Requirements from boundary conditions ... 282

Leadership team ... 283

Reliability and integrity coordinator ... 283

Inspectorate (Senior inspector) ... 283

WD operational staff ... 284

WD management ... 284

Conclusion: User requirements ... 284

1.7

Conclusion on requirements ... 284

APPENDIX M - Construction of contents of functional design ... 289

1. Functional Design ... 289

Integration of repair plan request and repair plan creation ... 290

Additional functions ... 291

APPENDIX N Introducing dependencies ... 294

1. Introducing dependencies ... 294

Method ... 295

Sequences ... 295

Repair plan inspection plan ... 295

Inspection plan

Judge ... 295

Judge

Repair ... 296

Redesign: Repair plan

Inspection plan

Judge

repair ... 296

Sequences ... 299

Repair

Inspect ... 299

Inspect Start up ... 299

Redesign: Repair

Inspect

Start Up ... 300

Sequences ... 302

Repair

Review ... 302

Redesign: Repair

Review ... 302

Conclusion introducing dependencies ... 303

APPENDIX O - Control system ... 305

1. Establishing a control system ... 305

1.1

Control theory ... 306

1.2

Control design ... 307

1.2.1

Making repair plan Making inspection plan

Judging ... 307

1.2.3

Repair & Inspect ... 310

1.2.4

Inspect

startup ... 311

1.2.5

Repair

review ... 312

1.2.6

Review completion ... 313

1.3

Conclusion ... 314

APPENDIX P - Incorporating temporary repair ... 315

1. Incorporating the temporary repair... 315

1.1

Method ... 315

1.2

Requirements ... 315

1.3

Functional design ... 315

1.3.1

Reducing streams ... 316

1.3.2

Integrating KE and TRep ... 317

1.3.3

Two situations ... 318

1.4

Temporary repair on equipment on VL53.003: Integrating ITP and TRep. ... 320

1.5

Temporary repair on equipment NOT on VL53.003 ... 322

1.6

Extension ... 323

1.7

Control of TRep process ... 323

1.7.1

Control of TRep on VL53.003 ... 323

1.7.2

Control of TRep NOT on VL53.003 ... 325

1.8

Emergency repairs ... 325

1.9

Scenarios ... 326

APPENDIX Q - Literature study on incompliance and violations ... 326

1. Theory study: Compliance with procedures ... 326

1.1

Consequences of human error ... 327

1.2

Danger of Incompliance ... 328

1.3

Types of violations ... 328

1.4

Who violates? ... 328

1.5

Modeling human behavior ... 329

1.5.1

Human behavior economic model... 329

1.5.2

Behavioral Cause model ... 330

1.5.3

Redefinition model ... 332

1.5.4

Conclusion on modeling behavior ... 332

1.6.1

Conflicting goals and faineance ... 333

1.6.2

Unrealistic procedures ... 333

1.6.3

Climate, culture and pressure exerted by management ... 334

1.6.4

Role of management ... 335

2. Theory study: Achieving compliance ... 335

2.1

Designing proper procedure ... 336

2.2

Promote safety and compliance through culture ... 337

2.3

Supervision ... 337

3. Conclusion on theory on compliance ... 339

APPENDIX R - Literature study on IT system use and acceptance 1 Literature

study on use and acceptance of IT systems ... 340

1.1 ERP systems ... 340

1.2 Success of IT systems or successful use of IT systems ... 341

1.3 Acceptance of IT systems ... 341

1.4 Technology Acceptance Model ... 341

1.5 Factors determining use of IT systems ... 342

1.5.1 Explaining argument for change ... 342

1.5.2 Understanding one’s position in the wholeness of systems ... 342

1.5.3 Prior usage and legacy systems ... 343

1.5.4 Same process conventions throughout organization ... 343

1.5.5 Functional match between system and reality ... 343

1.5.6 Data Integrity ... 343

1.5.7 Identify need for circumvention/ease of workaround ... 343

1.5.8 Interdependencies and short term consequences ... 344

1.5.9 Personal characteristics ... 344

1.5.10 Interface usability ... 344

1.5.11 Organizational support ... 344

1.5.12 Training ... 345

1.5.13 Culture and the role of management ... 346

1.5.15 Sequence of events of implementation ... 346

APPENDIX S -Discussion of KE form ... 347

The KE form ... 347

TRep Form ... 349

APPENDIX U - Concept of new procedure ... 352

APPENDIX V - Safety matrix ... 356

APPENDIX W - Work order print out ... 363

APPENDIX X – Adherence to requirements ... 365

APPENDIX Y – Adherence to theory ... 367

Summary (in Dutch)

Tronox Pigments (Holland) B.V. is de enige titaandioxide,TiO

producent in Nederland. Jaarlijks

produceert de in de Botlek, de bakermat van de Nederlandse chemische industrie, gelegen

fabriek jaarlijks zo’n 100 kiloton titaandioxide uit evenzoveel erts. TiO2 is een wit pigment welke

gebruikt wordt in papier, verf maar bijvoorbeeld ook in tandpasta. Het is een ongevaarlijk

product.

Bij de productie van TiO2 worden echter veel gevaarlijke chemische tussenproducten en

katalysatoren gebruikt. Met name de aanwezigheid van chloor en titaan tetrachloride zorgt voor

de nodige risico’s die beheerst dienen te worden. Om die reden heeft de overheid strenge regels

opgelegd aan grote chemische bedrijven zoals Tronox. Men is verplicht alle activiteiten zoals

productie maar ook onderhoud en inspecties beheerst te laten verlopen.

Daarnaast bestaan er specifieke regels omtrent het gebruik van drukapparatuur.

Drukapparatuur omvat alle apparatuur welke een volume onder druk bevat, zoals vaten en

ketels maar dus ook leidingwerk. De specifieke regels voor het gebruik van drukapparatuur

schrijven periodieke keuringen voor. Ook moet er voorafgaand aan een inspectie een plan

worden opgesteld welk goedgekeurd dient te worden door een externe toezichthouder (AKI,

Aangewezen Keurings Instelling). Na goedkeur mag de reparatie (of wijziging) uitgevoerd

worden volgens het plan. Tijdens of na reparatie worden inspecties uitgevoerd, eveneens

volgens het plan.

Nadat de reparatie opgeleverd is, wordt het plan en aangehechte documenten beoordeeld

(reviewed), en eveneens na goedkeur van de toezichthouder gearchiveerd.

De praktische uitvoering van het voornoemde proces is bij Tronox onderzocht. Vele

tekortkomingen zijn aan het licht gekomen welke ontegenzeggelijk inbreuk op de wetgeving

vormen en mogelijk ook afbreuk doen aan veiligheid.

Twee voornaamste hiaten welke zijn aangetroffen zijn ten eerste het feit dat de externe

toezichthouder AKI dikwijls pas achteraf wordt betrokken, en ten tweede wordt opgemerkt dat

de reparatie en inspectieplannen en aangehechte documenten dikwijls niet worden

geretourneerd en daarmee ook onbeoordeeld.

Uitgesloten kan niet worden of er hierdoor wellicht ongekeurde of ondeugdelijke apparatuur in

gebruik is genomen.

Een specifiek soort reparaties, tijdelijke reparaties, vertoonde vergelijkbare hiaten.

Ten aanzien van het achteraf betrekken van een AKI wordt gesteld dat dit een rudiment is van

eerder wetgeving waaronder deze situatie toegestaan was. Het betrekken van een AKI levert

downtijd op voor Tronox. Dat is de reden waarom men de Aki dikwijls achteraf betrekt.

De fabriek van Tronox wordt gekenmerkt door veel correctief onderhoud. De huidige wetgeving

voorziet in de mogelijkheid om een eigen inspectiedienst gecertificeerd te krijgen als IVG

(Inspectiedienst van de Gebruiker). Er gelden hiertoe voorwaarden op het gebied van opleiding,

onafhankelijkheid en procedures. Een IVG mag taken van de AKI zelfstandig uitvoeren zoals het

keuren van plannen voor reparatie en het uitvoeren van inspecties. Een dergelijke status zou

Tronox de mogelijkheid bieden om de huidige modus operandi min of meer voort te zetten, zij

het binnen een wettelijk kader in plaats van daarbuiten.

Tronox beschikt momenteel niet over de IVG status.

Een onderzoek naar de baten en kosten van de IVG status in vergelijking met opereren binnen

wettelijk kader zonder de IVG status is uitgevoerd.

Op basis van de resultaten is gekozen om de IVG status na te jagen aangezien de meeste

voorwaarden reeds zijn voldaan (bijv. opleiding). Gezien de grote hoeveelheid onverwachte

correctieve reparaties zou het betrekken van een AKI zeer veel downtime opleveren. Een IVG

status daarentegen biedt flexibiliteit.

Nu de eerste hiaat daarmee van de baan is, dient nog een herontwerp te worden gemaakt van

het reparatie en inspectieproces. Onderliggende oorzaak van het niet terugkeren van reparatie

en inspectieplannen ter review, is gelegen in het feit dat geen enkele prikkel bestaat om dat wel

te doen. Daarnaast wordt opgemerkt dat het papieren proces veel rompslomp oplevert en

beheersen van een niet digitaal proces nauwelijks doenlijk is.

Een herontwerp is gepresenteerd, rekening houdende met alle wettelijke bepalingen. Door de

reparatie en inspectieplannen te integreren met de werkorders in het ERP systeem worden de

broodnodige afhankelijkheden (prikkels) ingebouwd. Orders kunnen nu simpelweg geen

doorgang vinden zolang de nodige stappen niet zijn uitgevoerd.

Bovendien is een digitaal proces makkelijker te beheren. Afwijkingen of orders die te laat zijn

kunnen makkelijk worden opgespoord om vervolgens in te grijpen. Hiertoe wordt dan ook ,

naast het functionele ontwerp, een formeel beheerssysteem aangebracht.

Dat gezegd hebbende wordt onderkend dat geen enkel proces waterdicht is. Een aantal

scenario’s bestaan waarin het bedoelde procesverloop wordt overtreden. Aanvullende

maatregelen zijn daarom nodig om het reparatie en inspectie te laten verlopen zoals gewenst.

Het inbouwen van aanvullende prikkels, afhankelijkheden en sanctionering dienen te zorgen dat

dit laatste gebeurt.

Uit alle waarnemingen en theorie blijkt echter dat cultuur de grootste invloed heeft op het wel

of niet volgen van procedures. Hoewel de herontworpen processen het mogelijk maken, is een

aanvullende taak weggelegd voor het management om een cultuur te creëren waarin het niet

volgen van procedures, hoewel fysiek nooit tegen te houden, simpelweg not done is.,

Summary

Tronox Pigments (Holland) B.V. is the only TiO

producer in the Netherlands. Situated in the

heartland of Dutch chemical industry, this plant in the Botlek, Rotterdam turns around 100kT of

ore into TiO

annually. TiO

is a white pigment, found in paper, paint and for example

toothpaste. The product itself is non-toxic.

The production of TiO

does involve dangerous chemical substances as intermediate products

and catalysts. Specifically, chlorine and titanium tetrachlorine present risks that need to be

controlled. To this extent, authorities have placed the specific demand on large chemical

companies, such as Tronox, that all operations such as production, maintenance and inspections

are conducted in a controlled way.

Secondly, specific rules apply on the use of pressure equipment. Pressure equipment concerns

all equipment enclosing a volume under pressure, such as piping or vessels or boilers. The

specific rules on use of this equipment state that periodic inspections need to be carried out.

Furthermore, upon repair or modification, a plan needs to be issued first. This so called

‘inspection and test’ plan needs to be approved by an external inspectorate (AKI, Aangewezen

Keurings Instelling). After approval a repair or modification may commence. During or after the

repair or modification, inspections apply according to the inspection and test plan. After the

repair or modifications is complete, the inspection and test plan and accompanying

documentation of the operation are to be reviewed, approved by the external inspectorate and

filed.

A study was executed on the implementation of the repair and inspection process at Tronox.

The study revealed many shortcomings, which present definite breach of legislation and

possible risks to safety.

Two main hiatuses found were the fact that the AKI external inspectorate is often involved in

hindsight, and the fact that inspection and test plans and documentation remain largely

unreturned an thus reviewed. As a result, it is unclear whether uninspected or deficient

equipment is commissioned.

A study of a special class of repairs, temporary repairs revealed similar hiatuses.

With regard to involving the AKI in hindsight, it was concluded that the situation was acceded by

the AKI as a remnants of earlier legislation in which such a situation was allowed. Involving the

AKI in hindsight means Tronox is able to commence repairs and commission the plant

immediately, rather than having to await approval before repairing and before commissioning.

The Tronox plant is a plant where a lot of corrective (unexpected) maintenance occurs.

Current legal provisions offer the possibility of having a certified user inspectorate (IVG,

Inspectiedienst van Gebruiker). Conditions with respect to personnel, independence and

procedures apply. Such an IVG is allowed to perform tasks such as approving inspection and test

plans and inspecting repairs before commissioning. Such a status would allow Tronox to

continue its current modus operandi legally. Note that Tronox is currently not granted the status

and is in violation when involving an AKI in hindsight.

A study was performed to take stock of the costs and benefits if such an IVG status, as compared

to a fully compliant way of working without. It was decided to pursue certification as IVG, as

requirements such as personnel (education) are already met. Given the high amount of

unexpected corrective maintenance, it was calculated that the need to involve an AKI and

awaiting approval at all times would incur a large amount of downtime, whereas an IVG offers

flexibility.

Having defied the first hiatus, the second hiatus of the unreturned inspection and test plans is to

be addressed by redesigning the repair and inspection process. Root causes for the hiatus are

the fact that the current process includes no dependencies whatsoever with respect to whether

they are returned. On top of that, the fact that it is a paper process means that it is a burden to

adhere to the process and keeping track of all inspection and test plans is infeasible due to the

amount of paperwork.

After taking stock of all relevant legal demands, a functional redesign was made in which the

above shortcomings are attacked. By making the inspection and test plans an integrated part of

the work order in the ERP software, dependencies are incurred. Orders may not progress until

necessary steps are executed. Furthermore, being a digital system, it is easy to measure and

spot deficiencies such as unreturned or overdue items and execute subsequent control. To this

extent, a control system is designed on top of the functional design.

No process is completely impervious: Scenarios are defined as theoretical possibilities how the

process could be infringed. Additional measures are installed to mitigate the remaining risks.

The thesis concludes with discussing the system behavior. It will be motivated that, firstly, the

redesigned process can be adhered to, i.e. facilitates what it needs to, and meets all

requirements established. And secondly, the process will be adhered to due to the installed

dependencies, incentives and sanctioning.

However, culture is identified to be the main predictor of compliance. Although the redesign

facilitates a future compliant way of working, management commitment to compliance

throughout all operations is adamant. Specifically, a situation in which incompliance is no longer

condoned or regarded to be normal is to be established.

List of abbreviations

As referenced in main text or appendices:

Alphabetical as abbreviated:

AAKI

Aangemelde Aangewezen Keurings Instelling

AKI

Aangewezen Keuringsinstelling

AKVG

Aangemelde Keuringsdienst van Gebruiker

AlCl3

Aluminium Chloride

AMvB

Algemene Maatregel van Bestuur

ARBO

Arbeidsonstandigheden

ATEX

Atmosphere Explosive

AVR

Afvalverwerking Rijnmond

BD

Beleidsdocument (policy document)

BTP

Bestuurlijk Toezichts Programma

BEVI

Besluit Externe Veiligheid Inrichtingen

BIP

Bestuurlijk Inspectie Programma

BN

Bin

BRZO

Besluit Risico Zware Ongevallen

Cl2

Chlorine

CM

Column

CMMS

Computerised Maintenance Management System

C

Carbon

CCvD DA

Centraal College van Deskundigen – Drukapparatuur

CKI

Certificerings- en Keuringstinstelling

CO

Carbon monoxide

CO2

Carbon dioxide

DC

Dust collector (scrubber)

DCMR

Dienst Centraal Milieubeheer Rijnmond

DR

Dryer

EC

European Commission

EEC

European Economic Community

EEG

Europese Economische Gemeenschap (EEC)

ERP

Enterprise Resource Planning

et seq.

Et sequitur

E171

Food additive code of TiO

, issued by European Food Safety

Authority

FC

Furnace

FL

Filter

FTE

full time equivalent

HCL

Hydrochloric Acid

HP

Hold point

HSE

Health and Safety Executive, alt. Health, Safety and

Environment

HX

Heat exchanger

I&K

Inspectie en keuringstechniek

I&M

Infrastructuur en Milieu

IPO

Initial Public Offering alt. Interprovinciaal Overleg

ISO

International Standards Organisation

ITP

Inspection- and Test plan

IVG

Inspectiedienst van Gebruiker (User inspectorate)

IWE

International Welding Engineer

jis.

Junctis

jo.

Juncto

LAT RB

Landelijk Aanpak Toezicht Risico Bedrijven

LOC

Loss of Containment

LPG

Liquified Petroleum Gas

LPI

La Praktijk Ingenieur (IWE)

KPMS

Kerr-McGee Pigments Management System

KTA

Kiloton Annum

KVG

Keuringsdienst van Gebruiker

MHC

Major Hazard Control (Competent Authority Commodities act

pressure equipment

MIP

Meerjaren Inspectie Plan

NDT

Non Destructive Testing

NIL

Nederlands Instituut voor Lastechniek

NIM

New Inspection Method

NoBo

Notified Body

NVBR

Nederlandse Vereniging voor Brandweerzorg en

Rampenbestrijding

NYSE

New York Stock Exchange

OI

Operating Instructions

OvV

Onderzoeksraad voor Veiligheid

PBZO

Preventie Beleid Zware Ongevallen

PbEG

Publicatieblad van de Europese Gemeenschap

PED

Pressure Equipment Directive

PEU

Perceived ease of use

PGS

Publicatiereeks gevaarlijke stoffen

PRDA

Praktijkregels Drukapparatuur

PU

Perceived usefulness

RD

Review Documents

RISA

Richtlijn Specifiek Accreditatie Schema PED

RToD

Regels voor Toestellen onder Druk

RUD

Regionale Uitvoerings Dienst

RvA

Raad van Accreditatie

RvS

Raad van State

RWS

Rijkswaterstaat

SAP

Systeme, Anwendungen und Produkte (ERP software)

SHE

Safety, Health and Environment

SOK

Samenwerkings Overeenkomst

Stbl.

Staatsblad (State Journal)

StCr.

Staatscourant (State Gazette)

SP

Separator

SZW

Sociale Zaken en Werkgelegenheid

TAM

Technology Acceptance Model

TC

TiCl4 (Tronox specific abbreviation)

TCD

Technische Commissie Drukapparatuur

TiCl4

Titanium tetrachloride (‘Tickle’)

TiO

Titanium dioxide (‘pigment’)

TK

Tank

TPB

Theory of planned behavior

TRA

Theory of reasoned action

TREP

Temporary repair

UV

Ultraviolet (radiation)

VBS

Veiligheids Beheer Systeem (safety control system)

VGM

Veiligheid, Gezondheid en Milieu (SHE)

VI

Veiligheidsinstructie (safety instruction)

VL

Verzamellijs (collection list)

VMS

Veiligheids Management Systeem (safety management

system)

VNCI

Vereniging Nederlandse Chemische Industrie

VNG

Vereniging Nederlandse Gemeenten

VROM

Volkshuisvesting, Ruimtelijke Ordening en Milieu

VR

Veiligheidsrapportage alt. Veilgheids Regio

VS

Vessel

VvH

Verklaring van Herkeuring

VvI

Verklaring van Ingebruikname

WABO

Wet Algemene bepalingen omgevingsrecht

WD

Werktuigkundige dienst (Planning and job preparation dept.)

WECCO

western electro chemical company

WED

Wet op de Economische Delicten

WESA

Wet Specifiek Accreditatie Schema Drukapparatuur

WGHOR

Wet geneeskundige hulpverlening bij ongevallen en rampen

WIP

Work In Progress

WM

Wet Milieubeheer

WP

Witness point

WRZO

Wet rampen en Zware Ongevallen

WVR

Wet Veiligheidsregio’s

X

Examine

"un examen détaillé, complet et fréquent, effectué par

un homme compétent suffirait pour réduire de 75% au moins le

nombre d'explosion d'appareils à vapeur, d'autant plus que toute

machine peut, à la longue, évoluer vers un mauvais état qu'un

examen détaillé permettrait de reconnaître"

Robert Vinçotte, as early proponent of the usefulness of inspection regimes on steam equipment, 1872.

1.

Introduction

Toothpaste, an IPod, an aspirin tablet, sheets of paper and wall paint. Finding a common denominator of these products may seem farfetched. Yet a readily observable commonality, the white color of these products, is what ties them to each other and to the company Tronox.

The pigment that gives all the above mentioned products their bright vibrant white color is called titanium dioxide, abbreviated TiO2. In fact, most white surfaces found, ranging from mundane applications such as

lines on a road, up to exotic applications such as the coating on space crafts, owe their color to TiO2.

Tronox produces TiO2 out of ore. Using several continuous chemical processes, the ore is transformed

into TiO2 powder.

1.1

Tronox

This thesis describes a research conducted at, and presents analysis and results applicable specifically to the TiO2 production facility of Tronox at Botlek, the Netherlands. This plant is a subsidiary of the

international chemical company Tronox ltd.

Headquartered in Connecticut, Tronox features pigment production facilities in the Netherlands, USA and Australia. Besides chemical operations, Tronox has mineral sands operations in South Africa and Australia. The mineral sands being mined are partially used as feedstock for Tronox’s own chemical plants, the remainder is traded.

Worldwide, Tronox ltd. has 3500 employees across all operations. Tronox is among the largest producers of TiO2. For reference, [Appendix B] contains more detail on the history of Tronox [Appendix B 1.1] and

an elucidation of the current global operations of Tronox [Appendix B 1.2].

1.2

Titanium dioxide TiO

Titanium dioxide is used as white pigment in many applications, such as coatings and plastics. TiO2 is

sometimes referred to as ‘the perfect white’, because of its superior whiteness and opacity as compared to other white pigments as zinc oxide or lime.

TiO2 is non-toxic and is also found in food as additive E171. Global production is approximately 7 million

tons. More information on TiO2 is found in [Appendix B 1.3].

1.3

TiO

production at Tronox Botlek

Tronox Botlek facility is operated 24/7 to produce approximately 90kT per annum of TiO2. The plant has a

nominal capacity of approx. 100kTA, yet due to (either planned or unplanned) maintenance achieves an uptime of 90%.

Tronox Botlek has a staff of approximately 250 people, either own personnel or contractors.

The production of TiO2 uses the chloride process. This process consists of two main chemical reactions:

Chlorination (1) of titanium ore (already containing up to 95% of TiO2) to form TiCl4. The TiCl4 is oxidized

(2) to form pure TiO2 again. The chlorine is fed back to the chlorination step.

The two steps mentioned happen in a continuous process in what is referred to as plant 1. In a separate plant (indeed, plant 2), the TiO2 undergoes some mechanical treatments such as milling and drying. This

Figure 1. Systemic representation of TiO2 Production at Tronox Botlek.

More detail on the process in general [Appendix B 1.4], as well as specific details on the TiO2 production

[Appendix B 1.5] and operations [Appendix B 1.6] at Botlek are given in the [Appendix B].

1.4

Safety and environment

Although TiO2 is a non-toxic and harmless product, its production is concerned with the use of many

dangerous chemicals, imposing risks to human and environment. Chief amongst which is chlorine (Cl2).

The intermediate product TiCl4 (‘Tickle’) is a dangerous, highly corrosive and reactive substance. Over

seven hundred tons of TiCl4 are present at the premises of Tronox, as well as a thousand tons of

sulphuric acid and four hundred tons of hydrochloric acid.

The presence of these and many more chemical substances classifies Tronox among the most dangerous class of chemical industry. Under normal circumstances, no or limited substances are emitted. Substances are contained in equipment such as piping or vessels. In terms of safety, any loss of containment (LOC), e.g. a leakage or blowout is the prime risk present at Tronox.

1.5

Legislation and supervision

Owing to the risks present, Tronox’s operations are governed by a plethora of legislative provisions. An exhaustive study on all provisions1 applicable is performed [Appendix C]. This study has established exactly which legislation prevails in the remainder of this thesis. Specifically, the results of the study will allow us to:

• Determine whether current operations at Tronox are in compliance with prevalent legislation. • Establish a redesign which meets all legislative requirements.

Also, the summary of legislation, including references to specific articles, as presented in [Appendix C] is offered to the reader who wants to assess2 the contents of this thesis against legal determinations to allow him to do so without profound legal knowledge, or the need to take stock of legislation comprising over a thousand pages spread across various legal sources.

A final reason for performing such exhaustive study on legislation is the fact that within Tronox, no profound knowledge of the matter is present. Furthermore, it was noted that the subject of law is

1

European and national bills, guidelines, acts, orders, decrees, directives and jurisprudence.

2

i.e. be (practically) able to judge and test truthfulness, in accordance with the spirit of Popper’s theories of refutibility and falsifiability as per Popper, K. ‘The Logic of Scientific Discovery’. New York, USA: Basic Books, 1959.

especially apt to being discussed by laypersons enunciating many a myth3_{. The study allows separating}

myth from fact.

The study is found in [Appendix C], the results are summarized in the subsequent subparagraphs.

1.5.1

Legislation and safety

The (state of) equipment is the first barrier to prevent loss of containment. Ultimately, the state of equipment determines whether chemicals are contained or a leakage may occur.

To keep equipment in a fit state, maintenance is applied, and equipment is operated within operational limits.

A third barrier is presented by managing said maintenance and operations. For example, making sure all jobs are performed, within time. This third barrier is governed by so called BRZO legislation (Besluit Risico’s Zware Ongevallen). This legislation applies to high risk class of chemical companies. It demands companies to formalize the management of operations and maintenance, in a so called VMS (Veiligheids Management System) Safety Management System.

Figure 2. Safety barriers (green= preventive, orange = repressive).

To assure the legislative provisions are met, authorities conduct supervision (audits, reporting), as will be discussed in subsequent subparagraph. The supervision aims at both the preventive measures such as VMS Safety Management System as well as the repressive measures discussed next.

Legislation demands Tronox to have emergency plans and facilities such as a fire brigade, which come into play if and when an accident has occurred.

As final repressive measure, when all the above has failed, BEVI legislation (Besluit Externe Veiligheid Inrichtingen) applies. In short, this legislation determines that no housing is to be built within a certain perimeter of Tronox or vice versa, and it determines that certain types of chemical installations may not be neighboring to prevent ‘domino effects’.

Note that many more determinations stemming from legislation apply. Presented here are (the spirits of) the main provisions. For interested readers, more provisions and detail are found in [Appendix C 1]. Above and beyond any of the aforementioned, it is noted that BRZO includes an empty framework decree stating that, in short, Tronox should simply do whatever is necessary to operate safely4.

3

For example, many still refer to archaic law such as ‘Hinderwet’, or ‘Stoomwezen Equipment’, without being aware of exact provisions, and unaware of the fact that these Acts were revoked decades ago.

Also many general statements are made such as ‘this is legally allowed’ or ‘this is obligatory. By law’, without being able to state any source, rendering evaluation of the correctness of such statements impossble.

4

BRZO, Article 5, Clause 1 states: “He who operates an installation, takes all measures necessary to prevent major accidents and to limit the consequences thereof to both human and environment’.

BEVI (Spatial clearance)

Emergency Plan/Fire brigade etc.

BRZO Supervision

VMS Safety Management System

Maintenance and operation

Equipment

Note, any and all provisions which are relevant for the remainder of this thesis (specifically pressure equipment provisions [Appendix C 2]) will be discussed (or referenced) if and when relevant, leaving reading of the entirety of [Appendix C] discretionary.

1.5.2

Supervision

A study5 _{was also conducted on the supervision which the chemical industry in general, and as such}

Tronox, is subjected to. The study is found in [Appendix C 1, 1.3 et seq.].

This study was carried out to gain understanding of what authorities asses to be compliant or

incompliant. To illustrate, some legal provisions are very clear e.g. “a pump with electrical power above 100kW needs two emergency switches’’, yet some provisions are open to interpretation e.g. “owner of equipment must be in control of maintenance of equipment”.

However, the study revealed another conclusion with respect to supervision.

It was concluded that supervision on high risk companies is insufficient. In the last 15 years, the budget for supervision in general has been decreased fivefold. Besides bringing down budget, and hence the amount of supervisors and subsequently the amount of supervisory inspections (audits), another (resulting) change is witnessed.

Supervision audits used to be focused at on-site inspections of the state of equipment, presence of facilities etc. In recent years supervision has taken the form of what is called ‘system supervision’. In short, such supervision does not inspect the actual state of equipment or actual compliance (e.g. correct usage of tools, safety garments etc.). Rather, system supervision focuses on inspecting the management system of a company. When a management system is in order, it is implicitly assumed that the ‘physical reality’ suffices as well. The trend of system supervision (sometimes called horizontal

supervision, metasupervision, 2nd _{line supervision and supervision on supervision) is found in many areas,}

including such areas as finance and taxing.

Supervision on BRZO companies such as Tronox also constitutes system supervision. Only one or two days per year, an audit is conducted. The specific focal point (i.e. subject) of the audit is disclosed in advance, as is the moment of auditing.

Recent grave incidents with chemical companies have incurred criticism on the decreased and superficial ‘paper’ supervision conducted by authorities. Experts criticize the current supervision as being a paper reality and insufficient, as well as lacking knowledge and being too lenient.

Public opinion pursuant to recent incidents increasingly puts blame on supervisory bodies (competent authorities), besides the companies where the incident occurred itself.

Expert opinion and public pressure have led to, or are paralleled by, political pressure and initiatives to reconsider current supervision on chemical companies.

The above criticism is not just opinionated, but has taken formal cause as well. Most of recent severe accidents were followed by independent investigations into the accident and its run–up. Almost without exception, lack of supervision or enforcement is among the causes.

A verdict was recently enunciated in court presenting a novum: A competent authority was held liable for damage stemming from a fire at a company under its supervision. The judge’s verdict stated the

competent authority was ‘too forbearing’ in interpreting its (otherwise discretionary) supervision task. All of the above leads to the conclusion that supervision is absolutely insufficient, in that it is not able to spot deficiencies with respect to compliance and ultimately safety of the chemical industry. In other words, Tronox may by no means assume that passing an audit of a competent authority means that Tronox may conclude that no deficiencies exist. Therefore the study concludes:

5

Literature review and a series of interviews with several inspectorates in the chemical industry as well as competent authorities.

‘Tronox should assure itself of being in complete control of all processes with regard to maintaining and operating its equipment safely’

It is to be expected that supervision will be increased following recent criticism, and that enforcement will be more stringent and competent authorities less forbearing67. In fact bills have been proposed to do so. The above statement remains unaltered in the light of these developments.

1.6

Repair and inspection

Tronox produces TiO2, using chemical processes or mechanical treatments (e.g. drying, filtering). Safety

is defined to be the first priority within the company. Indeed, attention for safety is called for, since it was established that the production of TiO2 involves presence of high amounts of dangerous substances at

high pressure and temperature.

It was established that preventing loss of containment (LOC) of these substances boils down to making sure equipment does not fail. A chemical process has been defined (‘the recipe’), and equipment has been designed to facilitate.

We can deduce further then that an unsafe situation, as in loss of containment, which is the main danger at Tronox in general, can materialize when any of two things happens (or a combination):

1. The recipe is not adhered to and e.g. larger pressures exist, wrong reactions occur, meaning the equipment is not capable to contain.

2. The equipment does not meet its specifications (anymore), so that it is unable to contain the substances.

The first deviation could occur when the plant is operated beyond its operational limits, e.g. in terms of temperature or pressure. The subject is not discussed any further here and is left to the field of process engineering and control.

Equipment used in the plant is designed to cope with the chemical composition, phase, temperature, and especially pressure as intended in the chemical recipe. Obviously, equipment will not fail upon (mild) exceeding of these nominal characteristics, as a safety factor is always incorporated.

Figure 3. Severe yet typical corrosion on heat exchanger in corrosive medium (Left: new Right: several weeks of operation).

6

Since conducting the study [Appendix C] on supervision, Tronox was indeed subjected to unannounced, midnight (!), BRZO inspection. Also the frequency of audits has risen.

7

Since conducting the study [Appendix C] on supervision, it was indeed stated by the competent authority (of BRZO legislation as well as specific pressure equipment legislation), that they will enforce more stringently. “We will no longer apply the coercive penalty of fine anymore, rather a fine will be issued unwaveringly and immediately upon ascertion of incompliance.’ Anton J. Tol, director of Inspectie SZW, department MHC Major Hazard Control competent authority BRZO , ARBO, Warenwet. Enunciated at Praktijkregels Drukapparatuur Jaarcongres, December 4, 2012, the Hague, Netherlands. Attended

However, equipment experiences physical degradation. Equipment may be overdesigned to allow a certain amount of degradation, yet a situation may arise when equipment is simply unfit to perform its task safely anymore. Sometimes, this may be apparent when equipment is e.g. already leaking, sometimes it may be discovered upon a periodic inspection.

Whenever it is established that equipment is unfit, it needs to be repaired. The largest class of equipment at Tronox is static pressure equipment, such as vessels or piping. One could state that the whole factory consists of pressure equipment, with the exception of pumps and instruments (e.g. sensors) and civil construction (e.g. supports, fencing).

A subclass of such static pressure equipment is subject to an inspection regime. This means that it is to be periodically inspected, and that an inspection is to be conducted during or after a repair has taken place. This determines whether equipment is indeed fit to safely be commissioned.

The topic of repairs is even more relevant due to the fact that degradation, and hence the need for repairs, occurs in profusion at Tronox. The presence of highly corrosive chemicals such as TiCl4, Cl2, HCl

and the presence of solid material8 _{incurring abrasion and clogging, lead to a facility requiring high}

amounts9 _{of both corrective and preventive maintenance. Approximately 1000 work orders per month}

are issued for maintenance, incurring 1,5 million euro of maintenance costs every month.

Repairs are mostly conducted by contractors, and sometimes by the Tronox WD (Werktuigkundge Dienst) department (mechanical service department) who is also concerned with issuing and planning jobs, and accepting the result afterwards. Repairs are typically conducted on site at the Tronox premises, mostly requiring equipment to be shut down.

Inspections are carried out by Tronox’s inspectorate. This department of four inspectors is led by a sr.inspector. Inspectors are present during office hours, and available oncall 24/7 outside office hours.

Figure 4. Repair work being executed (note use of life air due to presence of chlorine etc.).

8

Ore and finished product are granular material, dissolved in slurry, and sand is blasted through certain parts to prevent clogging.

9

i.e. requiring maintenance effort well above what is considered average in the chemical industry at large in terms of OPEX fraction, or amount of forced shutdowns due to repairs.