An Overview of 

EPRI/BPIG RecommEPRI/BPIG Recomm

Program for Buried 

Bo ClarkEPRI, BOP Corrosion Program Industry/NRC Meeting on BurieOctober 22, 2009 White Flint, M
Introduction

• The EPRI/BPIG recommended program

“Recommendations for an Effective Prograto Control the Degradation of Buried Pipe”, Dec 2008 – Report # 1016456

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–Industry consensus document –Periodic updates (update in progress)

• Guidance for concrete pipe• Industry feedback from use

Document placed in Public Domain
Objectives of Document

Recommend program 

elements supporting:

– Safe and reliable 

operation of buried piping

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operation of buried piping

systems

– A best practices/ industry 

consensus approach
Basis

• Body of knowledge from 

– Oil and gas pipelines– Waterworks– Process plants

Power plants

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– Power plants

NACE – API – PRCI – ASTM – ASME – AWWA – E
Six-Step Program

Step 1 - Program Policy, Plan and Procedures

Step 2 - Risk Ranking

Step 3 Inspection

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Step

3 - Inspection

Step 4 - Fitness-for-Service

Step 5 - Repair

Step 6 – Prevention
Step 1 – Program Policy, Plan & Procedu

Step 1 - Program Policy, Plan and Procedures

Step 2 - Risk Ranking

Step 3 Inspection

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Step

3 - Inspection

Step 4 - Fitness-for-Service

Step 5 - Repair

Step 6 - Prevention
1. Procedures and Oversight

• Scope

– Both safety and non-safety– Piping designed to B31.1, B31.7, AWWA, Sect

and NFPA Codes

M t lli (f d f )

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–

M

e

t

allic (ferrous an

d nonferrous

)

• Intend to add concrete pipe in 2009

– Liquids, gases, and vapors

• Recommendations apply to both ID and OD initiat

degradation

– Can exclude ID if covered in another program
1. Procedures and Oversight (continue

• Policies and Procedures. A Buried Pipe Integri

Program Plan and implementing procedures shodeveloped. 

• Program Database. A database should be deve

t t k k d t d f i di 

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to 

trac

k

key program 

d

a

ta an

d performance indic

– Other related data such as CP and coating su

be documented 

• Performance Indicators. System or program he

reports and performance indicators should be defor the Buried Pipe Integrity Program.
Step 2 - Risk Ranking

Step 1 - Program Policy, Plan and Procedures

Step 2 - Risk Ranking

Step 3 Inspection

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Step

3 - Inspection

Step 4 - Fitness-for-Service

Step 5 - Repair

Step 6 - Prevention
2. Risk Ranking (continued)

• Risk Ranking 

– Prioritize the selection of inspection locations. – Series of matrices that correlates 

• the likelihood of failure against the consequences of fa

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2. Risk Ranking (continued)

The steps involved in Risk Ranking include:• Developing Scope Drawings• Route Confirmation• Scope Exclusions• Data Collection

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• Definition of Segments• Soil Analysis• Cathodic Protection Check• Over-the-Line Surveys• The Likelihood of Leak.• The Likelihood of Break• Failure Modes
2. Risk Ranking (continued)

• Segment risk is maximum of:

– Likelihood of ID or OD leak, break, or occlusion 

consequences of occurrence of the failure mode

• The risk ranking should be periodically reviewed an

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The risk ranking should be periodically reviewed an

updated as necessary.
Step 3 - Inspection

Step 1 - Program Policy, Plan and Procedures

Step 2 - Risk Ranking

Step 3 Inspection

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Step

3 - Inspection

Step 4 - Fitness-for-Service

Step 5 - Repair

Step 6 - Prevention
3. Inspections (continued)

• Inspections

– Should be performed at the piping locations th

the highest risk

– Access and cost may be considered when ran

equal

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• 4 means of direct pipe inspection:

– Entry or excavation– In-line inspection – Corrosion monitoring – Hydrotest

• Selection of the appropriate inspection method is 

the Owner
3. Inspections (continued)

Entry or Excavation• High risk segments can be uncovered to survey t

condition of the pipe and coating

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3. Inspections (continued)

Surface visual examinations can be performed to 

characterize pitting or cracking

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Pitt Measurements
3. Inspections (continued)

• Volumetric examinations can provide wall thick

FFS assessment

– Classic UT scan– On-line UT

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3. Inspections (continued)

In-line inspections of ID• Borescope• Robotics (source: RS Technical Services)• Direct access

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3. Inspections (continued)

• Intelligent pigs can be used to inspect high-risk 

– MFL pig– UT pig– Caliper pig

Tethered pig

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– Tethered pig

• Challenges

– Access openings– Pipe size changes– Bends– Valves– Cleanliness
3. Inspections (continued)

• Corrosion monitoring using corrosion coupons 

probes can be considered for high-risk (ID corrossegments

– Corrosion coupon– ER probe

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3. Inspections (continued)

• For high-risk (rupture likelihood segments) hydrote

option when the line is out-of-service. The test shoat anticipated pressure-transient pressure

C bk l lt i

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− Can back-calculate maximum 

flaw/pit geometries upon successful hydro

− ASME B31G
Step 4 – Fitness-for-Service

Step 1 - Program Policy, Plan and Procedures

Step 2 - Risk Ranking

Step 3 Inspection

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Step

3 - Inspection

Step 4 - Fitness-for-Service

Step 5 - Repair

Step 6 - Prevention
4. Fitness-for-Service (continued)

• Design Analysis: The integrity assessment shou

based on the design analysis of the buried piping 

– The analysis should be regenerated if it canno

retrieved. Loads to consider include:

• Minimum Code Requirement

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• Inspection Data• Run/Repair decision• Feedback to Risk Ranking
Step 4 – Fitness-for-Service (continued)

4

FFS

4.1

Design Margins

4.2

Inspection Results

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4.3

Integrity Analysis

4.2.1

Wall Thinning

4.2.2

Cracking

4.2.3

Mechanical Damage

Fl

API 579 / ASME FFS-1

CC N-513CC N-597

ASME B31G

NUREG/CR-6876 Caution

API 579 / ASME FFS-1

ASME XI

API 579 / ASME FFS-1

49 CFR
Six-Step Program

Step 1 - Program Policy, Plan and Procedures

Step 2 - Risk Ranking

Step 3 Inspection

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Step

3 - Inspection

Step 4 - Fitness-for-Service

Step 5 - Repair

Step 6 - Prevention
5. Repairs (continued)

• Pre-Approved Repair Options should be in place 

prompt implementation in case a buried pipe fails. detailed design of the selected repair should accomthe specifics of the failure.

• Leak Detection and Isolation techniques and opt

h ld b l d f i l i 

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should be pre-selected for prompt implementation 

leak occur.
5. Repair Techniques (continued)

Step 5

Repairs

5.1 Non-Welded 5.2 Welded

5 1 1 Leak Strap 5 2 1 

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5.1.1 Leak Strap

5.1.2 Mechanical Clamp

5.1.3 Wrap

5.1.4 Insertion Liner

5.2.1 

5.2.2 Fillet 

5.2.3 

5.2.4 
5. Non-Welded Repairs - Clamps

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5. Non-Welded Repairs - Wraps

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5. Non-Welded Repairs - Liners

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5. Welded Repairs

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Fillet-Welded Patch Welded Leak 
Step 6 – Prevention and Mitigation

Step 1 - Program Policy, Plan and Procedures

Step 2 - Risk Ranking

Step 3 Inspection

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Step

3 - Inspection

Step 4 - Fitness-for-Service

Step 5 - Repair

Step 6 – Prevention and Mitigation
Prevention and Mitigation

Unacceptable Risk?

YES NO

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-

-

Preventive Measures

-NO

-

Mitigative Me

Reduce Likelihood 

of Failure

Leak Detec

Repair
6. Prevention and Mitigation (continued)

Preventive Measures

Water Treatment & Cleaning

Coatings

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Linings

Cathodic Protection

Pipe Material Selection

Trench Fill Material

Leak Detection
6. Prevention and Mitigation (continued)

• Resistant materials can 

virtually eliminate susceptibility 

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Use of High Density Polyethylene
EPRI’s Survey on Buried Pipe Prog

• July 2009 Informational Survey

– Roughly gauge industry’s implementation of B

programs

• Survey asked questions such as:

–

N

u

mber 

of ope

ratin

g

units

t

hat h

a

v

e begun 

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© 2009 Electric Power Research Institute, Inc. All rights reserved.

u be o ope at g u ts t at a e begu

implementing a Buried Pipe Integrity Program 

– Has Corporate document governing BPIP bee

issued?

– Have Site-Specific document(s) governing BP

issued?

– Number of operating units that have BPIP prog

basis document and database.
EPRI’s Survey on Buried Pipe Prog

• Survey questions (continued)

– Has Guided Wave (GW) been performed on h

areas, as determined by BPIP database?

– What actions have been employed as a result 

information gained from your BPIP (such as ca

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protection, alternative material used for replacpermanent monitoring techniques, etc.)?

– Have you excavated buried piping for the sole 

of performing inspections?
EPRI’s Survey on Buried Pipe Prog

• Survey Results

– Over 90% of units have begun implementing a 

Pipe Integrity Program (BPIP)

– 24 of 27 responding utilities have issued BPIP 

procedures

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– 14 of 27 utilities have performed GW on high r

piping

– 8 of 27 utilities have excavated solely for pipe 

inspection
Together...Shaping the Future 

Electricity

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