**NRC INSPECTION MANUAL**	IRIB

INSPECTION PROCEDURE 71111 ATTACHMENT 07

# HEAT EXCHANGER/SINK PERFORMANCE

Effective Date: 01/01/2024

PROGRAM APPLICABILITY:	IMC 2515 A

CORNERSTONES:	Initiating EventsMitigating SystemsBarrier Integrity

INSPECTION BASES:	See IMC 0308, Attachment 2

# SAMPLE REQUIREMENTS

# 71111.07-01	INSPECTION OBJECTIVES

01.01	To verify that any potential heat exchanger or heat sink deficiencies which could mask degraded performance are identified. Applies to all risk significant or safety-related heat exchangers directly or indirectly connected to service water systems or the ultimate heat sink (UHS), including heat exchangers in closed cooling water systems.

01.02	To verify that any potential commoncause heat exchanger or heat sink performance problems that have the potential to increase risk are identified (e.g., icing and grassing at circulating and service water intake structures or discharge silting).

01.03	To verify that the licensee has adequately identified and resolved heat exchanger or heat sink performance problems that could result in initiating events or affect multiple heat exchangers in mitigating systems and thereby increase risk (e.g., component cooling water heat exchanger performance affected by corrosion, fouling, or silting).

# 71111.07-02	GENERAL GUIDANCE

Apply risk informed insights together with other factors, such as engineering analysis and judgment, operating experience, previous inspection results, performance history, and renewed licensee aging management or other program actions (e.g., inspections, tests, etc.) that the licensee agreed to implement to determine which heat exchangers or heat sinks will be selected for review. Consider previously inspected heat exchangers or heat sinks during the previous years to avoid duplication.

When performing this inspection, consider refueling outage and at-power maintenance schedules to identify opportunities to observe infrequent activities associated with risk significant heat exchangers, heat sinks, or service water inspections/testing (e.g., heat exchanger inspections and testing, internal service water pipe inspections, external underground service water pipe inspections).

For plants with a renewed license, aging management programs and implementing activities may have resulted in additional or different requirements and/or commitments. The inspector should review these aging management program descriptions and commitments as part of informing sample selections. The applicable aging management programs may include, but are not limited to: open-cycle cooling water, closed treated water systems, water chemistry, selective leaching, and buried and underground piping and tanks. Additionally, licensees may have conducted one-time, internal surface inspections of components in the cooling water systems associated with the heat exchangers or the UHS. These inspections would have been in accordance with the one-time inspection and inspection of internal surfaces in miscellaneous piping and ducting components aging management programs.

Refer to the table below for guidance on sample selection, which should focus on those activities that have a risk priority (i.e., those common-cause failures with a reasonable probability of occurring should be targeted by inspection to determine impact on cornerstones). Additional information with regards to heat exchanger or heat sink inspections can be found in IP 71111.21M, appendix E.

For each sample, routine review of problem identification and resolution activities should be conducted using IP 71152, “Problem Identification and Resolution.” Problems involving silting, water hammer, voiding, corrosion, and fouling should be reviewed. Focus on events or conditions that could cause the loss of a heat exchanger/sink due to events such as heat transfer problems, improper cleaning, ice buildup, grass intrusion, leaks/breaks, or blockage of pipes and components. Determine whether the licensee has appropriately considered commoncause failures. If any loss of heat exchanger/sink events have occurred, these should receive review priority. Review the corrective actions to determine if actions were enough to prevent/address recurrence of the problem.

# 71111.07-03	INSPECTION REQUIREMENTS

## 03.01	Heat Exchanger/Sink.

Verify heat exchanger and/or heat sink readiness and availability.

Specific Guidance

a. Heat exchanger/sink performance can be reviewed by observation, by evaluating test data/reports, or both. These tests should be those typically sanctioned by industry. Test acceptance criteria and results have appropriately considered differences between testing conditions and design conditions (functional testing at design heat removal rate may not be practical); and the test results have appropriately considered test instrument inaccuracies and differences.

b. Verify periodic maintenance activities are with consistent licensee commitments made in response to Generic Letter (GL) 89-13. The principal Electric Power Research Institute (EPRI) guidance documents related to GL 89-13 program implementation are TR107397, “Service Water Heat Exchanger Testing Guidelines,” for service water heat exchanger thermal performance testing, and 1003320, “Supplemental Guidance for Testing and Monitoring Service Water Heat Exchangers.” Early guidance consisted of EPRI NP-7552, “Heat Exchanger Performance Monitoring Guidelines,” although it has largely been replaced by the additional detail in TR-107397. Guidance is provided in EPRI 1009839, “Heat Exchanger Single Tube Test Device,” for an alternative heat exchanger test method which does not require testing of the entire tube bundle.

c. Bio-fouling controls can be reviewed by observation, by evaluating data/reports, or both. The licensee should have acceptance criteria for bio-fouling controls which are based on an industry standard, supportive program results, or the recommendation of the appropriate vendors.

d. Heat exchanger inspections can be observed to identify the state of tube cleanliness and the number and condition of plugged tubes. Primarily focus on whether the number of tubes plugged affects the heat exchanger's operability and not the biofilm on the inside of tubes (see IP 71111.21M, appendix E for more guidance). The licensee should have acceptance criteria that indicates the maximum number of tubes that may be plugged for a specific heat exchanger and a basis for that acceptance criteria.

e. Check, by either a walkdown or the review of operations data, any or all of the following:

1. The heat exchanger’s inlet and/or outlet temperatures.

2. Primary or secondary side fluid flow.

3. If there is any evidence of leaks.

4. Whether the heat exchanger can perform its safety-related or risk significant function by reviewing documentation or results of licensee inspections.

5. Comparison of end bell orientation of one heat exchanger to the orientation of a similar redundant train heat exchanger, to confirm proper orientation. Improper end bell orientation can significantly reduce or isolate flow to an otherwise functional heat exchanger.

f. Determine if heat exchanger is correctly categorized under the Maintenance Rule and verify if it is receiving the required maintenance.

# 71111.07-04	REFERENCES

IMC 0308, Attachment 2, “Technical Basis for Inspection Program”

IMC 2515, Appendix A, “RiskInformed Baseline Inspection Program”

IP 71111.01, “Adverse Weather Protection”

IP 71111.21M, “Comprehensive Engineering Team Inspection”

IP 71152, “Problem Identification and Resolution”

EPRI NP-7552, “Heat Exchanger Performance Monitoring Guidelines” (Call the NRC Technical Library to get a copy of this if needed.)

EPRI TR-106438, “Water Hammer Handbook for Nuclear Plant Engineers” (Call the NRC Technical Library to get a copy of this if needed.)

TR-107397, “Service Water Heat Exchanger Testing Guidelines”

TR-1003320, “Supplemental Guidance for Testing and Monitoring Service Water Heat Exchangers”

EPRI 1009839, “Heat Exchanger Single Tube Test Device”

TEMA Standards, “Standards of the Tubular Exchanger Manufacturers Association”

ASME OM-S/G Part 21, “Inservice Performance Testing of Heat Exchangers in Light-Water Reactor Power Plants”

NUREG 1275 Vol. 3, “Operating Experience Feedback Report- Service Water System Failures and Degradations”

NUREG/CR-5865, “Generic Service Water System Risk-Based Inspection Guide”

NUREG/CR-0548, “Ice Blockage of Water Intakes”

Generic Letter 89-13, “Service Water System Problems Affecting Safety-Related Equipment”

Generic Letter 91-13, “Request for Info Related to the Resolution of GI 130, "Essential Service Water System Failures at Multi-Unit Sites”

Generic Letter 96-06, “Assurance of Equipment Operability and Containment Integrity During Design-basis Accident Conditions”

Generic Letter 96-06, “Assurance of Equipment Operability and Containment Integrity Supplement 1 During Design-basis Accident Conditions”

Bulletin 79-15, “Deep Draft Pump Deficiencies”

Bulletin 88-04, “Potential Safety-Related Pump Loss [strong-pump to weak-pump interaction, and minimum flow requirements]”

IN 80-07, “Pump Shaft Fatigue Cracking”

IN 93-68, “Failure of Pump Shaft Coupling Caused by Temper Embrittlement”

IN 94-45, “Potential Common-Mode Failure for Large Vertical Pumps”

IN 2004-07, “Plugging of Safety Injection Pump Lubrication Oil Coolers with Lakeweed”

IN 2006-17, “Recent Operating Experience of Service Water Systems due to External Conditions”

IN 2007-05, “Vertical Deep Draft Pump Shaft and Coupling Failures”

IN 2007-06, “Potential Common Cause Vulnerabilities in Essential Service Water Systems”

RG 1.27, “Ultimate Heat Sink for Nuclear Power Plants”

RG 1.127, “Inspection of Water-Control Structures Associated with Nuclear Power Plants”

See the following Web links for reference documents:

IHS Codes and Standards:https://drupal.nrc.gov/tech-lib/35748 (non-public)

NRC Technical Library:https://drupal.nrc.gov/tech-lib (non-public)

END

Issue Date: 05/25/06	-  -	71111.07

13

71111.07	-  -			       Issue Date: 01/31/08

Issue Date: 08/18/23	1	71111.07

Attachment 1: Revision History for IP 71111.07

Issue Date: 08/18/23	Att1-1	71111.07