XI.M27 (NUREG-2191 R0)

XI.M27 FIRE WATER SYSTEM

Program Description

This aging management program (AMP) applies to water-based fire protection system components, including sprinklers; nozzles; fittings; valve bodies; fire pump casings; hydrants; hose stations; standpipes; water storage tanks; and aboveground, buried, and underground piping and components that are tested in accordance with the applicable National Fire Protection Association (NFPA) codes and standards. Full-flow testing and visual inspections are conducted in order to ensure that loss of material, cracking, and flow blockage are adequately managed. In addition to NFPA codes and standards, portions of the water-based fire protection system that are: (a) normally dry but periodically are subject to flow (e.g., dry-pipe or preaction sprinkler system piping and valves) and (b) that cannot be drained or allow water to collect, are subjected to augmented testing or inspections. Also, portions of the system (e.g., fire service main, standpipe) are normally maintained at required operating pressure and monitored such that loss of system pressure is immediately detected and corrective actions are initiated.

Either sprinklers are replaced before reaching 50 years inservice or a representative sample of sprinklers from one or more sample areas is tested by using the guidance of NFPA 25, “Inspection, Testing and Maintenance of Water-Based Fire Protection Systems.” Generic Aging Lessons Learned for Subsequent License Renewal (GALL-SLR) Report AMP XI.M41, “Buried and Underground Piping and Tanks,” is used to monitor the external surfaces of buried and underground water-based fire protection system piping and tanks.

Evaluation and Technical Basis

1. Scope of Program: Components within the scope of water-based fire protection systems include items such as sprinklers, nozzles, fittings, valve bodies, fire pump casings, hydrants, hose stations, fire water storage tanks, fire service mains, and standpipes. The internal surfaces of water-based fire protection system piping that is normally drained, such as dry-pipe sprinkler system piping, are included within the scope of the AMP. Fire hose stations and standpipes are considered piping in the AMP. Fire hoses and gaskets can be excluded from the scope of license renewal if the standards that are relied upon to prescribe replacement of the hose and gaskets are identified in the scoping methodology description.

2. Preventive Actions: Flushes (e.g., NFPA 25, Section 7.3.2.1) mitigate or prevent fouling, which can cause flow blockage or loss of material, by clearing corrosion products and sediment.

3. Parameters Monitored or Inspected: Loss of material and cracking could result in system failure. Flow blockage due to fouling from the buildup of corrosion products or sediment in the system could occur. Therefore, the parameters monitored are the system’s ability to maintain required pressure, flow rates, and the system’s internal conditions. Periodic flow tests, flushes, internal and external visual inspections, and testing of sprinklers are performed. When visual inspections are used to detect loss of material, the inspection technique is capable of detecting surface irregularities that could indicate an unexpected level of degradation due to corrosion and corrosion product deposition. Where such irregularities are detected, follow-up volumetric wall thickness examinations are performed. Volumetric wall thickness inspections are conducted on portions of water-based fire protection system components that are periodically subjected to flow but are normally dry. Visual examinations of cementitious materials are conducted to detect indications of loss of material and cracking that could affect the system’s ability to maintain pressure.

4. Detection of Aging Effects: Water-based fire protection system components are subject to flow testing (except for fire water storage tanks), other testing, and visual inspections. Testing and visual inspections are performed in accordance with Table XI.M27-1, “Fire Water System Inspection and Testing Recommendations.” Unless recommended otherwise, external visual inspections are conducted on a refueling outage interval.

Flow tests confirm the system is functional by verifying the capability of the system to deliver water to fire suppression systems at required pressures and flow rates.
Visual inspections are capable of evaluating: (i) the condition of the external surfaces of components, (ii) the conditions of the internal surfaces of components that could indicate wall loss or cracking, and (iii) the inner diameter of the piping as it applies to the design flow of the fire protection system (i.e., to verify that corrosion product buildup has not resulted in flow blockage due to fouling). Internal visual inspections used to detect loss of material are capable of detecting surface irregularities that could be indicative of an unexpected level of degradation due to corrosion and corrosion product deposition. Where such irregularities are detected, follow-up volumetric examinations are performed.
Visual inspection of yard fire hydrants, fire hydrant hose hydrostatic tests, gasket inspections, and fire hydrant flow tests are conducted to provide opportunities to detect degradation before a loss of intended function can occur.

Portions of water-based fire protection system components that have been wetted but are normally dry, such as dry-pipe or preaction sprinkler system piping and valves, are subjected to augmented testing and inspections beyond those of Table XI.M27-1. The augmented tests and inspections are conducted on piping segments that cannot be drained or piping segments that allow water to collect:

In each 5-year interval, beginning 5 years prior to the subsequent period of extended operation, either conduct a flow test or flush sufficient to detect potential flow blockage, or conduct a visual inspection of 100 percent of the internal surface of piping segments that cannot be drained or piping segments that allow water to collect.
In each 5-year interval of the subsequent period of extended operation, 20 percent of the length of piping segments that cannot be drained or piping segments that allow water to collect is subject to volumetric wall thickness inspections. Measurement points are obtained to the extent that each potential degraded condition can be identified (e.g., general corrosion, MIC). The 20 percent of piping that is inspected in each 5-year interval is in different locations than previously inspected piping.

If the results of a 100-percent internal visual inspection are acceptable, and the segment is not subsequently wetted, no further augmented tests or inspections are necessary.

For portions of the normally dry piping that are configured to drain (e.g., pipe slopes towards a drain point) the tests and inspections of Table XI.M27-1 do not need to be augmented.

The inspections and tests of all water based fire protection components occur at the intervals specified in NFPA 25, or as modified by Table XI.M27-1. Fire water storage tank bottom surfaces exposed to soil or concrete are inspected in accordance with GALL-SLR Report AMP XI.M29, “Outdoor and Large Atmospheric Metallic Storage Tanks,” Table XI.M29-1. For indoor fire water storage tanks exposed to concrete, this only applies if the tank bottom to concrete interface surface is periodically exposed to moisture.

If the environmental (e.g., type of water, flowrate, temperature) and material that exist on the interior surface of the underground and buried fire protection piping are similar to the conditions that exist within the above grade fire protection piping, the results of the inspections of the above grade fire protection piping can be extrapolated to evaluate the condition of buried and underground fire protection piping for the purpose of identifying inside diameter loss of material.

The water-based fire protection systems are normally maintained at required operating pressure and monitored in such a way that loss of system pressure is immediately detected and corrected when acceptance criteria are exceeded. Continuous system pressure monitoring or equivalent methods (e.g., number of jockey fire pump starts or run time) are conducted.

Inspections and tests are performed by personnel qualified in accordance with site procedures and programs to perform the specified task. The inspections and tests follow site procedures that include inspection parameters for items such as lighting, distance, offset, presence of protective coatings, and cleaning processes.

Aging effects associated with fire water system components having only CLB intended functions of leakage boundary (spatial) or structural integrity (attached) as defined in the Standard Review Plan for Review of Subsequent License Renewal applications for Nuclear Power Plants (SRP-SLR) Table 2.1-4(b) may be managed by the GALL-SLR Report AMP XI.M36, “External Surfaces Monitoring of Mechanical Components,” and GALL-SLR Report AMP XI.M38, “Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components.” Flow blockage due to fouling need not be managed for these components.

Table XI.M27-1. Fire Water System Inspection and Testing Recommendations^{1, 2, 5, 9}
Description	NFPA 25 Section
Sprinkler Systems
Sprinkler inspections⁵	5.2.1.1¹⁰
Sprinkler testing⁷	5.3.1
Standpipe and Hose Systems
Flow tests	6.3.1
Private Fire Service Mains
Underground and exposed piping flow tests	7.3.1
Hydrants	7.3.2¹⁰
Fire Pumps
Suction screens	8.3.3.7¹⁰
Water Storage Tanks
Exterior inspections	9.2.5.5¹⁰
Interior inspections	9.2.6⁴, 9.2.7
Valves and System-Wide Testing
Main drain test	13.2.5¹⁰
Water Spray Fixed Systems
Strainers (after each system actuation)	10.2.1.6¹⁰, 10.2.1.7¹⁰, 10.2.7¹⁰
Operation test (refueling outage interval)	10.3.4.38
Foam Water Sprinkler Systems
Strainers (after each system actuation)	11.2.7.1
Operational Test Discharge Patterns (annually)⁶	11.3.2.6¹⁰
Storage tanks (internal–10 years)	Visual inspection for internal corrosion
Obstruction Investigation
Obstruction, internal inspection of piping³	14.2 and 14.3
All terms and references are to NFPA 25. The staff cites NFPA 25 for the description of the scope and periodicity of specific inspections and tests. This table specifies those inspections and tests that are related to age-managing applicable aging effects associated with loss of material and flow blockage for passive long-lived in-scope components in the fire water system. Inspections and tests not related to the above continue to be conducted in accordance with the plant’s CLB. If the CLB specifies more frequent inspections than required by NFPA 25 or this table, the plant’s CLB continues to be met. A reference to a section includes all sub bullets unless otherwise noted. Section 5.2.1.1 includes Sections 5.2.1.1.1 through 5.2.1.1.7. The alternative nondestructive examination methods permitted by Sections 14.2.1.1 and 14.3.2.3 are limited to those that can ensure that flow blockage will not occur. In regard to Sections 9.2.6.4 and 9.2.7: When degraded coatings are detected, the acceptance criteria and corrective action recommendations in GALL-SLR Report AMP XI.M42 are followed in lieu of Section 9.2.7 (1), (2), and (4). When interior pitting or general corrosion (beyond minor surface rust) is detected, tank wall thickness measurements are conducted as stated in Section 9.2.7 (3) in the vicinity of the loss of material. Vacuum box testing as stated in Section 9.2.7 (6) is conducted when pitting, cracks, or loss of material is detected in the immediate vicinity of welds. Items in areas that are inaccessible because of safety considerations such as those raised by continuous process operations, radiological dose, or energized electrical equipment are inspected during each scheduled shutdown but not more often than every refueling outage interval. Where the nature of the protected property is such that foam cannot be discharged, the nozzles or open sprinklers are inspected for correct orientation and the system tested with air to ensure that the nozzles are not obstructed. For wet pipe sprinkler systems, the subsequent license renewal application either: * Provides a plant-specific evaluation demonstrating that the water is not corrosive to the sprinklers (e.g., corrosion-resistant sprinklers); or * Proposes a one-time test of sprinklers that have been exposed to water including the sample size, sample selection criteria, and minimum time in service of tested sprinklers; or * Proposes to test the sprinklers in accordance with NFPA 25 Section 5.3.1.1.2. If past testing results demonstrate that potential nozzle plugging does not impede discharge patterns or prevent the discharge pattern from reaching wetted surfaces to be protected, the test frequency does not exceed 3 years. Otherwise, tests are conducted annually except protected components that are inaccessible because of safety considerations such as those raised by continuous process operations, radiological dose, or energized electrical equipment are tested during each scheduled shutdown but not more often than every refueling outage interval. Calibration of measuring and test equipment is conducted in accordance with plant-specific procedures in lieu of NFPA 25 requirements. Where NFPA 25 or this table cite annual testing or inspections, testing and inspections can be conducted on a refueling outage interval if plant-specific OE has shown no loss of intended function of the in-scope SSC due to aging effects being managed for the specific component (e.g., loss of material, flow blockage due to fouling).

5. Monitoring and Trending: Visual inspection results are monitored and evaluated. System discharge pressure or equivalent methods (e.g., number of jockey fire pump starts or run time) are monitored continuously and evaluated. Results of flow testing (e.g., buried and underground piping, fire mains, and sprinkler), flushes, and wall thickness measurements are monitored and trended. Degradation identified by flow testing, flushes, and inspections is evaluated.

Where practical, degradation identified is projected until the next scheduled inspection. Results are evaluated against acceptance criteria to confirm that the timing of subsequent inspections will maintain the components’ intended functions throughout the subsequent period of extended operation based on the projected rate of degradation. For sampling-based inspections, results are evaluated against acceptance criteria to confirm that the sampling bases (e.g., selection, size, frequency) will maintain the components’ intended functions throughout the subsequent period of extended operation based on the projected rate and extent of degradation.

6. Acceptance Criteria: The acceptance criteria are: (a) the water-based fire protection system is able to maintain required pressure and flow rates, (b) minimum design wall thickness is maintained, and (c) no loose fouling products exists in systems that could cause flow blockage in the sprinklers or deluge nozzles.

7. Corrective Actions: Results that do not meet the acceptance criteria are addressed in the applicant’s corrective action program under those specific portions of the quality assurance (QA) program that are used to meet Criterion XVI, “Corrective Action,” of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B. Appendix A of the GALL-SLR Report describes how an applicant may apply its 10 CFR Part 50, Appendix B, QA program to fulfill the corrective actions element of this AMP for both safety-related and nonsafety-related structures and components (SCs) within the scope of this program.

If the presence of sufficient foreign organic or inorganic material to obstruct pipe or sprinklers is detected during pipe inspections, the material is removed and the inspection results are entered into the site’s Corrective Action Program for further evaluation.

If a flow test (i.e., NFPA 25 Section 6.3.1) or a main drain test (i.e., NFPA Section 13.2.5) does not meet acceptance criteria due to current or projected degradation (i.e., trending) additional tests are conducted. The number of increased tests is determined in accordance with the site’s corrective action process; however, there are no fewer than two additional tests for each test that did not meet acceptance criteria. The additional inspections are completed within the interval (i.e., 5 years, annual) in which the original test was conducted. If subsequent tests do not meet acceptance criteria, an extent of condition and extent of cause analysis is conducted to determine the further extent of tests. At multi-unit sites, the additional tests include at least one test at the other unit on site, or one of the units at a three unit site with the same material, environment, and aging effect combination.

An evaluation is conducted to determine if deposits need to be removed to determine if loss of material has occurred. When loose fouling products that could cause flow blockage in the sprinklers is detected, a flush is conducted in accordance with the guidance in NFPA 25 Appendix D.5, “Flushing Procedures.” If any projected inspection results will not meet acceptance criteria prior to the next scheduled inspection, inspection frequencies are adjusted as determined by the site’s corrective action program.

8. Confirmation Process: The confirmation process is addressed through those specific portions of the QA program that are used to meet Criterion XVI, “Corrective Action,” of 10 CFR Part 50, Appendix B. Appendix A of the GALL-SLR Report describes how an applicant may apply its 10 CFR Part 50, Appendix B, QA program to fulfill the confirmation process element of this AMP for both safety-related and nonsafety-related SCs within the scope of this program.

9. Administrative Controls: Administrative controls are addressed through the QA program that is used to meet the requirements of 10 CFR Part 50, Appendix B, associated with managing the effects of aging. Appendix A of the GALL-SLR Report describes how an applicant may apply its 10 CFR Part 50, Appendix B, QA program to fulfill the administrative controls element of this AMP for both safety-related and nonsafety-related SCs within the scope of this program.

10. Operating Experience: Operating experience (OE) shows that water-based fire protection systems are subject to loss of material due to corrosion, MIC, or fouling; and flow blockages due to fouling. Loss of material has resulted in sprinkler system flow blockages, failed flow tests, and piping leaks. Inspections and testing performed in accordance with NFPA standards coupled with visual inspections are capable of detecting degradation prior to loss of intended function. The following OE may be of significance to an applicant’s program:

In October 2004, a fire main failed its periodic flow test due to a low cleanliness factor. The low cleanliness factor was attributed to fouling because of an accumulation of corrosion products on the interior of the pipe wall and tuberculation. Subsequent chemical cleaning to remove the corrosion products from the pipe wall revealed several leaks. Corrosion products removed during the chemical cleaning were observed to settle out in normally stagnant sections of the water-based fire protection system, resulting in flow blockages in small diameter piping and valve leak-by. [Discussions as part of Requests for Additional Information are available at Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML12220A162, ML12306A332, and ML13029A244].
In October 2010, a portion of a preaction spray system failed its functional flow test because of flow blockages. Two branch lines were found to have significant blockages. The blockage in one branch line was determined to be a buildup of corrosion products. A rag was found in the other branch line. (ADAMS Accession No. ML13014A100).
In August 2011, an intake fire protection preaction sprinkler system was unable to pass flow during functional testing. Subsequent visual inspections identified flow blockages in the inspector’s test valve, the piping leading to the inspector’s test valves, and three vertical risers. The flow blockages were determined to be a buildup of corrosion products. (ADAMS Accession No. ML113050425).
In March 2012, the staff and licensee personnel found that a portion of the internally galvanized piping of a 6-inch preaction sprinkler system could not be properly drained because the drainage points were located on a smaller diameter pipe that tied into the side of the 6-inch pipe. A boroscopic inspection of the lower portions of the pipe showed that it contained residual water, that the galvanizing had been removed, and that significant quantities of corrosion products were present whereas in the upper dry portions, the galvanized coating was still intact. (Information Notice 2013-06).

The review of plant-specific OE during the development of this program is to be broad and detailed enough to detect instances of aging effects that have occurred repeatedly. In some instances, repeatedly occurring aging effects (i.e., recurring internal corrosion) might result in augmented aging management activities. Further evaluation aging management review line items in SRP-SLR Sections 3.2.2.2.7, 3.3.2.2.7, and 3.4.2.2.6, “Loss of Material due to Recurring Internal Corrosion,” include criteria to determine whether recurring internal corrosion is occurring and recommendations related to augmenting aging management activities.

The program is informed and enhanced when necessary through the systematic and ongoing review of both plant-specific and industry OE including research and development such that the effectiveness of the AMP is evaluated consistent with the discussion in Appendix B of the GALL-SLR Report.

References

10 CFR Part 50, Appendix B, “Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants.” Washington, DC: U.S. Nuclear Regulatory Commission. 2016.

NFPA. NFPA 25, “Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, 2011 Edition.” Quincy, Massachusetts: National Fire Protection Association. 2011.

US NRC. Information Notice 2013-06, “Corrosion in Fire Protection Piping Due to Air and Water Interaction.” Agencywide Documents Access and Management System (ADAMS) Accession No. ML13031A618. Washington, DC: U.S. Nuclear Regulatory Commission. March 25, 2013.

XI.M27 (NUREG-2191 R0)

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