Issue Date: 11/07/11 - 1 - 65001.21

ATTACHMENT 65001.21

INSPECTION OF PIPE RUPTURE HAZARDS ANALYSES (INSIDE AND OUTSIDE 

CONTAINMENT) DESIGN ACCEPTANCE CRITERIA (DAC)-RELATED ITAAC

PROGRAM APPLICABILITY: 2503

65001.21-01 INSPECTION OBJECTIVES

01.01 To verify that the pipe break hazard analysis report, as defined in the Design 

Certification Document (DCD) was completed in accordance with the 

methodology called out in the DCD, and any additional requirements provided in 

license conditions in the COL FSAR.

01.02 To determine whether licensee records establish an adequate basis for the 

acceptance for closure of Inspection, Test, Analysis and Acceptance Criteria 

(ITAAC) for the as-designed pipe rupture hazards analysis report.

65001.21-02 INSPECTION REQUIREMENTS AND GUIDANCE

Background: Design Acceptance Criteria (DAC) are a set of prescribed limits, 

parameters, procedures, and attributes upon which the NRC relies, in a limited number 

of technical areas, in making a final safety determination to support a design 

certification. DAC is to be objective (measurable, testable, or subject to analysis using 

pre-approved methods), and must be verified as a part of the ITAAC performed to 

demonstrate that the as-built facility conforms to the certified design (SECY 92-053). 

There are three process options for DAC/ITAAC resolution: 

• Resolve during the design certification or amendment to the design certification 

• Resolve as part of COL review 

• Resolve after COL is issued 

In the first two options, the applicant will submit the design information and the NRC will 

document its review in a safety evaluation. In the third option, the COL holder notifies 

the NRC of availability of design information and the staff will document its review in an 

inspection report.

Should the third option be implemented for a first standard plant design, subsequent 

COL applicants may reference the first standard plant closure documentation and close 

the DAC/ITAAC under the concept of “one issue, one review, one position,” identified in 

NRC guidance. 
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Description of the Pipe Rupture Hazards Analysis Report ITAAC: The as designed pipe 

rupture hazards analysis report ITAAC is a set of methodology and criteria pertaining to 

protection of essential systems or components inside and outside containment from the 

adverse effects of postulated failures in high and moderate energy piping (HELB and 

MELB). However, this ITAAC cannot be completed until after the piping design has 

been completed and the piping DAC has been met. After the plant is built, the as built 

pipe rupture hazards analysis report ITAAC will verify that the as designed pipe rupture 

hazards analysis inside and outside containment is still valid.

02.01 Inspection Plan/Scoping.

The scope of piping Pipe Rupture Hazards Analysis Report ITAAC encompasses all 

high-energy and moderate-energy fluid systems in the proximity of essential systems, 

structures, and components (SSCs) inside and outside containment.

The design commitment is as follows: “Systems, structures and components (SSCs) 

that are required to be functional during and following a design basis event shall be 

protected against, or qualified to withstand, the dynamic and environmental effects 

associated with analyses of postulated failures in high and moderate energy piping.”

02.02 Design Inspections. The following tasks should be performed across a 

representative sample of high and moderate energy piping systems:

a) Review the As-Designed Pipe Rupture Hazards Analysis Report to verify that 

each space containing structures, systems, and components (SSCs) important to 

safety is addressed.

b) Review the As-Designed Pipe Rupture Hazards Analysis Report to verify for 

each chosen piping segment that the methodology called out for determination of 

postulated pipe break and crack types and locations in the license is followed. 

Aspects that should be verified include:

Criteria for determining the pipe breaks/cracks location including their 

associated pipe stress and cumulative usage factor

Criteria for determining the pipe break types and crack sizes

Computer codes used in analyses are approved for use in the 

DCD/license

c) Review the As-Designed Pipe Rupture Hazards Analysis Report to ensure the 

methodology called out for the evaluation of dynamic effects and environmental 

effects of postulated pipe breaks/cracks in the license is followed. Aspects that 

should be verified include:
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Criteria for determining the jet expansion modeling and the jet 

impingement force 

Design of the mitigation features (i.e., pipe whip restraints and jet 

impingement barriers)

Design of the SSCs for which mitigation features are not provided.

Criteria for the protection of flooding and other adverse environmental 

effects

d) Review the As-Designed Pipe Rupture Hazards Analysis Report to verify that 

SSCs which are identified to be the potential targets will be protected as required 

in the license by the associated mitigation features as-designed. This includes 

the review of the sketches of applicable high energy piping systems showing the 

location, size and orientation of postulated pipe breaks and the location of pipe 

whip restraints, jet impingement barriers, and the SSCs important to safety which 

are in close proximity to the postulated pipe rupture locations. It also includes 

review of the isolation and separation provided in the plant design. The level of 

review should be guided by inspector experience, risk significance of the SSCs, 

operating experience in determining the design of physical protection provided to 

the SSCs important to safety.

e) Review the As-Designed Pipe Rupture Hazards Analysis Report to verify the 

report addresses all of the information required in the license.

Guidance: The inspection should involve a review of the pipe rupture hazard analysis 

report to verify those aspects required to be covered in the DCD are fully addressed in 

accordance with the methodology described in the DCD. Inspectors should be 

prepared to refer to the acceptance criteria defined in Sections 3.6.1 and 3.6.2 of 

NUREG-0800 during the reviews of the As-Designed Pipe Rupture Hazards Analysis 

Report. 

Branch Technical Position (BTP) 3-4 in the SRP would be a good reference for this 

review. This could include, but may not be limited to:

Review the pipe break locations in high energy piping to verify that the DCD 

methodology was followed to identify the locations and that no locations were 

missed;

Review through-wall crack locations in high and moderate energy piping to verify 

that the DCD methodology was followed to identify the locations and that no 

locations were missed;

Review essential structures, systems, and components to ensure that all were 

addressed in the report;

Review evaluation of consequences of pipe whip and jet impingement (for 

rooms with both high energy breaks and essential items, confirm that there is no 

adverse interaction between the essential items and the whipping pipe or jet and 

that the plant layout is modified as required to provide separation to protect 

essential systems); evaluate consequences of flooding, environment, and 

compartment pressurization;

Evaluate consequences of flooding, environment, and compartment 
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pressurization in the break exclusion zones in the vicinity of containment 

penetrations due to 1.0 square foot breaks in the main steam and feedwater 

lines evaluate the design and location of protective hardware;

Review isometric piping sketches that identify the break locations, the basis for 

these locations and the protective hardware which mitigates the consequences 

of these breaks; 

 

The system selection criteria for inspection should consider risk significance, operating 

experience, new design, complexity of system transients, and safety significance of the 

essential SSCs. As a minimum, the pipe rupture hazard analysis report should be 

completed prior to beginning the inspection. If not completed, the report portions 

applicable to the spaces the licensee claims are ready for review should be complete. 

The inspectors should review the design-appropriate “Risk Insights” document during 

selection of essential SSCs. (e.g., Risk Insights for the Review of the AP1000 Design, 

Rev 1.) 

Inspection Sample Guidance: The Pipe Rupture Hazards Analysis Report ITAAC 

inspection should verify at least 10 to 15 isolation and/or physical protection 

mechanisms with different characteristics. 

During the preparations for the inspection, the team should select a sample of 15 to 20 

piping HELB and MELB design packages and identify those packages to the licensee 

and piping design contractor/vendor. The final sample selection of 10 to 15 packages 

for review will be done when the team arrives at the location of the inspection. For the 

purpose of this inspection, a design package is defined as all of the design information 

involved with a particular HELB or MELB location, and the isolation and/or physical 

protection mechanisms associated with that particular location.

02.03 As-Built Inspections: Once construction and the reconciliation of the pipe rupture

hazard analysis are complete, inspection for this ITAAC can commence. On a sampling 

basis, review systems in the field after they are constructed to observe the protective 

hardware installed to mitigate consequences of pipe breaks and verify that they were 

installed in accordance with the design and the reconciliation analysis. Confirm by walk 

down that a sample of installed piping configuration and support hardware is installed 

per the piping design and piping ISOs.

Review the pipe rupture hazard analysis report to determine where the report was 

reconciled for changes made to the plant with regard to placement of mitigation features 

such as pipe whip restraints, jet impingement barriers, drainage systems, and physical 

separation of piping, equipment, and instrumentation, etc. Verify that the changes were 

done in accordance with the methodology called out in the DCD and the COL FSAR. 

The guidance above can be followed in verifying that the changes were handled in 

accordance with the regulations and license.

65001.21-03 RESOURCE ESTIMATE 

The estimated hours for completing the piping DAC inspection are 210 to 280 staff 

hours based on a two weeks audit/inspection by three or four NRC staff members. In 

addition, the estimated hours for preparation and documentation are 70 hours and 120 
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hours respectively. Additional hours may be required if the inspection is performed in 

parts.

65001.21-04 REFERENCES

ASME B&PV Code Section III, Applicable Revision

Facility Final Safety Analysis Report (FSAR) and Design Certification Document (DCD)

Facility Final Safety Evaluation Report (SER)

10 CFR 50, Appendix A, General Design Criterion 4 – Environmental and Dynamic 

Effects Design Bases

NUREG-0800, Standard Review Plan (SRP) for the Review of Safety Analysis Reports 

for Nuclear Power Plants, Section 3.6.1 “Plant Design for Protection Against Postulated 

Piping Failures in Fluid Systems Outside Containment”

NUREG-0800, Standard Review Plan (SRP) for the Review of Safety Analysis Reports 

for Nuclear Power Plants, Section 3.6.2 “Determination of Rupture Locations and 

Dynamic Effects Associated with the Postulated Rupture of Piping”

NRC Branch Technical Position 3-3, "Protection Against Postulated Piping Failures in 

Fluid Systems Outside Containment."

NRC Branch Technical Position 3-4, "Postulated Rupture Locations in Fluid System 

Piping Inside and Outside Containment."

END
Issue Date: 11/07/11 Att-1 65001.21

Attachment 1

Revision History For 65001.21

Commitment 

Tracking 

Number

Document

Accession

Number and

Issue Date

Description of Change Training 

Needed

Training 

Completion 

Date

Comment Resolution 

Accession Number

N/A 11/07/11

CN 11-029

ML112231754

Initial issuance. This IP has been 

developed by Region II staff to 

address inspection of Design 

Acceptance Criteria (DAC) related to 

pipe break hazard analysis. The 

DAC are sometimes referred to as 

"design ITAAC" and are intended to 

be inspected in a manner similar to 

other ITAAC that are part of a COL.

It is anticipated that inspections of 

DAC will generally be conducted by 

NRO technical staff in a support role 

to Region II Center for Construction 

Inspection. 

N/A N/A N/A