ML20116L987

Portions of Diesel Fuel Oil Sys License Renewal Technical Rept, Written for License Renewal Technical Rept Template Phase 2 Development

ML20116L987
Person / Time
Site:	Calvert Cliffs
Issue date:	07/25/1996
From:	BALTIMORE GAS & ELECTRIC CO.
To:
Shared Package
ML20116E148	List: ML20116L948 ML20116L965 ML20116L970 ML20116L976 ML20116L987
References
NUDOCS 9608190238
Download: ML20116L987 (17)

Text

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For LR Technical Report Template Development July 25,1996 I

I 7.6 COMPONENTSUPPORTS i l

7.6.1 Scoping Commodity Descrintion in accordance with 10 CFR 54.2i, the scope of this report is limited to passive, long-lived component supports. For the purposes of this discussion,

• component suppon" is dermed as the connection between a system, or component within a system, and a plant structural member (e.g., the concrete floor or wall, structural beam or column, or ground outside the plant buildings). Supports for both the distributive portions of systems, such as piping and cable raceways, and system equipment items are included in the scope of this report. Supports for the reactor vessel and steam generators are not included in this commodity evaluation but are addressed in a separate License Renewal Application Section. Systems having component supports addressed in this section are identified in Table 7.6-1.

Equipment supports are discussed in various sections in the UFSAR including 5.1.2.3,5A.2.1.1,5A.3.2,10.1.2, i 1.4.11 and 6.2. I A commodity approach was determined to be an appropriate approach for an AMR of the various system )

component supports based on the following:

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> Although the systems within the scope oflicense renewal are diverse in function and physical appearance, the component supports within them are very similar with respect to factors that affect aging. For example, spring hangers in the service water system and the main steam system serve the same function in each system and are physically similar.

> Component supports in diverse systems but subject to the same environment and loading conditions will degrade in a similar fashion.

The total population of component supports are grouped into categories based upon their application in the plant and then into component support types. Component suppon types are based on similarities of design, loading condition, and environment.

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Sconed SCs and Their Intended Functions As discussed in the IPA Methodology section on commodity evaluations, component supports were scoped using a  ;

process similar to the component level scoping process for structures. A generic list of component support types I was developed by reviewing industry and plant-specific information, including Seismic Qualification Utility Group guidance, American Society of Mechanical EngineersSection XI component support inspection documentation and the CCNPP System Level Scoping Results. All component support types which provide support to equipment -

I within the scope of LR were identified as within the scope oflicense renewal. All component supports within the scope of license renewal were considered to be subject to aging management review except snubbers, which were excluded by 10 CFR 54.21(a)(1)(i). The results of this step are shown in Table 7.6-2. ,

Component supports subject to an AMR were determined to have the following passive intended functions:

a. Provide structural support for safety-related systems and components.

b. Provide structural and/or functional support, or both, for non-safety-related equipment where failure of this structural component could directly prevent satisfactory accomplishment of safety-related functions.

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c. Provide structural support for non-safety-related systems and components which are required for fire protection, environmental qualification, pressurized thermal shock, anticipated transients without scram, and station blackout, and credited in the analysis for these events included in the current licensing basis (CLB).

9608190238 960801 7 PDR ADOCK 05000317 P PDR ii

For-LR Technic:1 Report Templit: Devziopmsnt July 25,1996 ,

TABLE 7.6-1 SYSTEMS WITHIN THE SCOPE OF LICENSE RENEWAL CONTAINING SUPPORTS WITHIN THE COMMODITY EVALUATION Electrical 125 Volt DC Distribution (002) Auxiliary Feedwater (036) f Electrical 4 kV Transformers and Busses (004) Demineralized Water and Condensate Storage (037)

Electrical 480 Volt Transformers and Busses (005) Sampling System (Nuclear Steam Supply System Electrical 480 Volt Motor Control Centers (006) [NSSS])(038)

Well and Pretreated Water (008) Chemical and Volume Control (041)

Service Water Cooling (011) Circulating Water (042)

Saltwater Cooling (012) Condensate (044)

Fire Protection (013) Feedwater(045)

Component Cooling Water (015) Technical Support Center Computer (047)

Instrument AC (017) Emergency Safety Features Actuation (048)

VitalInstrument AC(018) Control Rod Drive Mechanisms and Electrical (055)

Compressed Air (019) Reactor Protection (058)

Data Acquisition Computer (020) Primary Containment HVAC (060)

Diesel Fuel Oil (023) Containment Spray (061)

Emergency Diesel Generators (024) Control Boards (062)

Annunciation (026) Reactor Coolant (064) j Plant Heating (029) Spent Fuel PoolCooling(067) l Control Room Heating, Ventilation and Air Waste Gas (069) i Conditioning (HVAC)(030) Hydrog-n Recombiner (073)

Auxiliary Building and Radwaste Heating and Area ano 'rocess Radiation Monitoring (077/79)

Ventilation System (032) Nuclear Instmmentation (078)

Main Steam (083)

Lighting and Power Receptacles (097)

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For LR Technical R! port Templite Developm:nt July 25,1996 TABLE 7.6-2 SUPPORT COMMODITY COMPONENT TYPES REOUIRING AN AMR Component Support Group Associated Systems i Piping Supports Spring Hangers, Constant Load Supports, Sway Struts, Rod 008,011,012,013,015,019,023,024, Hangers, and Snubber Supports' Outside Containment 029,036,037,038,041,045,052,061, Spring Hangers, Constant Load Supports, Sway Struts, Rod 067,083 Hangers, and Snubber Supports1 Inside Containment (Note 1)

Piping Frames Outside Containment Piping Frames inside Containment Cable Raceway Supports Channel, Clamp, and Other Supporting Styles Outside Cables are not assigned to specific Containment systems.

Channel, Clamp, and Other Supporting Styles inside Containment HVAC Ducting Supports Rod Hanger Trapeze Supports Outside Containment 030,032 Rod Hanger Trapeze Supports inside Containment 060 Equipment Supports Anchorage including Elastomer Vibration Isolators 030,032 Electrical Cabinet Anchorage Outside Containment 002,004,005,006,017,018,020,024, 026,038,048,055,057, 058,062, 077/79, 078,097 (Note 2)

Electncal Cabinet Anchorage Inside Containment 077/079 Electrical Equipment (load bearing insulation mr. serial) 002,004,005 Equipment Frames (Instruments / Batteries on Racks) 002,008,011,012,015,019,023,024, Outside Containment 029,030,032,036,038,042,044,045, 052,061,067,069,083 Equipment Frames (Instruments on Racks)Inside 013,038,041,045,052,064,073,083 Containment Frames and Saddles (Tanks and Heat Exchangers) Outside 011,012,013,015,019,023,024,029, Containment 036,038,041,061,064,067,069,  !

Frames and Saddles (Tanks and Heat Exchangers) Inside 041,052,064,073 l

Containment j Metal Spring isolators and Fixed Bases Outside 008,011,012,013,015,019,023,024, Containment 029,032,036,041,044,052,061,067, Metal Spring Isolators and Fixed Bases Inside Containment 060,064 4 ,

Loss-of-Coolant Accident (LOCA) Restraints 064 l Ring Foundations for Flat-Bottom Vertical Tanks 008,023,037,052 Note 1: Correlation of piping support types to individual systems is not relevant to the AMR results. See more j discussion under " Piping Supports." i Note 2: Local control panels and distribution panels in a variety of fluid systems were evaluated in the Electrical Panels Commodity Evaluation and their supports are included in this support group.

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Snubber supports include the hardware from the wall and piping / equipment to the snubber pin connections.

The snubber itself is not subject to AMR.

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For LR Technic:1 Rrport Templite Devel:pment July 25,1996 7.6.2 Aging Management The potential age-related degradation mechanisms (ARDMs) for component supports are identified in Table 7.6-3.

Those ARDMs which were not evaluated for a group of supports because they are not applicable to the group are noted by shading the corresponding blocks in this table. Those that were evaluated but were determined to be not plausible for any group of suppons in this commodity evaluation are listed in a note to the table. Those ARDMs which were evaluated but determined to be not plausible for a panicular group of supports have an "N/A" in the table for the unaffected group of suppons. Those ARDMs identified as plausible for a group of supports are noted by a check mark (/) in the appropriate columns in Table 7.6-3.

Where ARDMs were determined to be plausible, an aging management strategy was selected which involves both methods to mitigate the effects of the plausible ARDMs and methods to discover their effects. For component supports, discovery methods involve two separate but complementary sets of activities. The first set of activities consists of baseline walkdowns or inspections which are conducted one time to determine whether the plausible ARDMs are actually occuning for the suppons potentially affected. The second set of activities involves follow-on actions which occif repetitively during the period of extended operation. The nature of the follow-on actions is dictated by the results of the baseline inspection or walkdowns. For example, if no evidence is found that the plausible ARDM is occurring during the baseline inspection, the follow-on actions credited may consist of periodic documented walkdowns by system engineers to ensure that this condition continues. If evidence of significant aging is found for certain groups during the baseline activities, follow-on actions consist of aging management activities that are formulated to address the condition discovered during the baseline inspection. Baseline and I

follow-on activities are discussed in more detail under each component support group heading.

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Far LR Techi,ic-I Report Templite Developmmt

. J Iy 25,1996 TABLE 7.6-3 POTENTIAL AND PLAUSIBLE ARDMs FOR EQUIPMENT SUPPORTS Component Types for Which ARDM is Plausible Piping Supports Cable Raceway Supports HVAC Ducting Supports Spong Hangers, Spnng Hangers, Channel, Clamp, Constant Load Constant Load Piping Frames Piping Frames and Other Channel, C! amp, Rod Hanger, Rod Hanger, Potential ARDMs Supports, Sway Supports, Sway Outside inside Supporting Styles and Other Trapeze Supports Trapeze Supports Struts, Rod Hangers. Struts, Rod Hangers, Containment Containment Outside Supporting Styles Outside inside Containment and Snubber and Snubber Containment inside Containment Containment Supports Outside Supports inside Containment Containment General, Corrosion of y / / / / / / y Steel Elastomer Hardening Loading Due to Rotating /

Reciprocating M chinery Loading Due to / / N/A N/A Hydraulic Vibration or W.ter Hammer Loading Due to / / N/A N/A Thermal Expansion of Piping / Component Other Loading / N/A / '

N/A / N/A / N/A (Abuse, impacts.

Accidents)

Note: Not plausible for entire commodity group: - radiation embrittlement of steel - thermal effects on steel

- grout / concrete local deterioration - lead anchor creep

- stress corrosion cracking of high strength bolting i

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T For LR Technic I Riport Template Development J11y 25,1996 TABLE 7.6-3 (continued)

POTENTIAL AND PLAUSIBLE ARDMs FOR EQUIPMENT SUPPORTS Equipment Support Types for Which ARDM is Plausible l Equipment Frames and Frarnes and Equipment Sadd!es Ring prames Saddles Potential ARDMs Anchorage Electncal Electrical Electrical Frames Metal Spring Metal Spring LOCA Foundation ruments (Tanks & (Tanks &

including Cabinet Cabinet Equip. (bad (Instruments Heat Heat isolators & lsolators & Restraints for Flat-Elastomer Anchorage Anchorage s on Fixed Bases Fixed Bases

, bearing on racks) Exchangers Exchangers bottom Vibration Outside inside insulation ) Inside Outside inside

• Outside Inside Vertical isolators Containment Containment material) Containment Containment Containment Containment Containment Tanks General / / / / / / / / / / / /

Corrosiori of Steel Ellstomer / /

H:rdening _

Lording Due to N/A / / /

Rotating /

Reciprocating Michinery Lording Due to / / /

Hydrautic Vibration or Water Htrnmer Loading Due to / / N/A /

Thermal Expansion of Piping /

Component Other Loading / / N/A / / N/A / N/A / N/A N/A /

(Abuse, Impacts.

Accidents)

Note: Not plausible for entire commodity group: - radiation embrittlement of steel - thermal effects on steel

- grout / concrete local deterioration - lead anchor creep

- stress corrosion cracking of high strength botting i

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For LR Technic:1 Report Templite Developmrnt July 25,1996 Piping Supports A wide variety of piping support types are installed in systems within the scope oflicense renewal depending on the design requirements ofindividual piping configurations. During the Aging Management Review, those piping suppons which contain threaded fasteners in their load bearing path were evaluated separately from those without such fasteners. Within each of these types, supports inside containment were evaluated separately from those outside since the environment in containment is typically more severe for aging and provides fewer opportunities for routine discovery of degraded conditions. Tables 7.6-2 and 3 show the resulting four groups of piping supports.

Even though the AMR determined that different piping support types are subject to different aging mechanisms, with few exceptions all types of piping supports were determined to be subject to the same aging effects and these effects are managed in a similar manner. Therefore, piping supports of all types are addressed in this section and any discussion which only applies to a particular type is noted as such.

Pining Sunnorts - Materials and Environment. Piping supports are constructed of structural steel (typically carbon steel) and are located inside containment and other climate controlled buildings.

Pining Supnorts - Plausible Agine Mechanisms and Effects on Intended Functions. As shown in Table 7-63, general corrosion, loading due to hydraulic vibration, loading due to thermal expansion and other loading (abuse, impacts, accidents) are the ARDMs considered to be plausible for piping supports.

General corrosion is plausible for all piping supports because normal humidity levels in the plant could result in moisture coming into contact with the structural steel supports. During the plausibility determination, no credit is taken for the protective paint coating applied to these supports; however, this protective coating plays an important role in the aging management approach for piping supports.

Loading due to hydraulic vibration and thermal expansion is considered plausible for spring hangers, constant load supports, sway struts and rod hangers because these types of suppons have threaded fasteners in the load bearing path which could be loosened by such loading. Piping supports are designed to accommodate a broad range ofloading conditions. However, over time normal and off-normal loading could result in degraded suppon conditions.

Loading due to thermal expansion was determined to be not plausible for snubber supports because, by design, snubbers do not restrict movement due to thermal expansion. Loading due to hydraulic vibration was determined to be plausible for snubber supports because snubbers do restrict this type of movement.

Piping supports without threaded fasteners in the load bearing path are only used in applications where loading due to hydraulic vibration and thermal expansion are small relative to other design loads.

Therefore, loading due to thermal expansion and hydraulic vibration were determined to be not plausible for this type of support.

Other loading (abuse, impacts, accidents) was determined to be a plausible ARDM for all piping supports outside of containment. Piping systems inside containment are accessible for a much shorter time period than similar systems outside of containment. Additionally, containment closeout inspections prior to restart would discover any degraded conditions of piping supports inside containment prior to operating the system at power. Consequently, this ARDM was determined to be not plausible for piping supports of all types inside containment.

Stress corrosion cracking (SCC) of support bolting was determined to be not plausible, both inside and outside of containment. Industry experience has shown that high strength bolting (i.e. those with yield strength peater than 150 KSI) installed in some NSSS applications inside containment could be subject to stress corrosion cracking in a humid environment. However, the conclusion has been reached that there is no high strength bolting installed in piping support applications at CCNPP for the following reasons -

. Industry experience with SCC of high strength bolting in a humid environment has shown that such high strength bolting is likely to fail in a matter of months after installation.

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l For LR Technical Report Tempitte Development July 25,1996 Such failures would have been discovered and corrected during the routine plant operations and maintenance activities including the baseline discovery activities discussed in the following paragraphs.

Additionally, plant construction practices would have made it highly unlikely that high strength bolting would be installed in such applications during plant construction even though equipment specifications typically did not place an upper limit on bolting strength.

• Current design standards for piping supports do contain guidance on bolting materials to be used for piping supports.

Because the conclusion has been reached that there is no high strength bolting in piping support applications, SCC was determined to be not plausible for piping supports.

The effects of general corrosion on piping supports would be a loss of support material and consequently a reduction in component support strength if the ARDM were allowed to progress unmanaged. The effects ofloading due to hydraulic vibrations, thermal expansion and other loading would initially be loosened threaded fasteners in the load bearing path of the support. If these mechanisms were hft unmanaged, the effects could progress to the point of reducing the amount of support afforded to the piping and/or allowing j excessive motion of the supported piping. This failure of the piping supports' intended faction could, in turn, lead to failure of the piping pressure boundary under normal or more severe loading covUtions.

1 Piping Supoorts - Methods to Manage the ARDMs. Methods to mar. age aging of the piping supports are discussed in two categories. Mitigation measures are activities which reduce the likelihood or rate of the 4 I

ARDMs. Discovery techniques are those that can reasonably detect the effects of aging prior to loss of intended function.

To mitigate the effects of general corrosion, the conditions on the extemal surfaces of the piping supports must be controlled. Significant rates of corrosion related ARDMs only occur when the piping supports come into contact with moisture. Preventing direct and prolonged contact between metal surfaces and ,

l moisture is an effective mitigation technique for general corrosion. For mitigation of the other plausible ARDMs, piping support design requirements in accordance with original piping support specifications require that the piping supports accommodate a broad range ofloading conditions. Any piping system modifications which involve piping su; ports also account for a range ofloading conditions equivalent to that required by the initial design specifications.

The effects of the general corrosion are detectable by visual techniques. Because much of the external metal surfaces of the piping supports are covered by a protective coating (paint), observing that significant degradation has not occurred to this coating is an effective method to ensure that corrosion has not affected the intended function of the piping supports. Because the paint does not contribute to the intended function of the supports, observing the paint for degradation provides an alert condition which would trigger -

corrective action before degradation of the support's ability to perform its intended function. The effects of excessive loading from thermal expansion, hydraulic vibrations or other loading (abuses, impacts, accidents) are observable initially in the form ofloosened threaded fasteners in the load bearing path of the support, nerefore, adequate discovery techmques for piping support aging need to include both a visual observation of the general condition of the supports to address general corrosion and observation of the piping suppons for loose parts, loosened fasteners and adequate tightness of bolting to address the loading-related ARDMs.

Elping Sucoorts -Identification and Description of Aging Management Programs. A combination of mitigation and discovery methods are implemented in CCNPP programs and activities to manage the effects of aging on the intended function of piping supports. The plant programs and activities described below apply to all piping supports ivithin the scope of license renewal with the exceptions noted.

A combination of plant programs and activities ensure that the external metal surfaces of the piping supports are not in contact with a moist, aggressive environment. One program preserves the protective l coating (paint) which covers much of the piping support and serves as an effective measure to mitigate the 8

For LR Technic:1 Report Templite Development July 25,1996 onset of general corrosion. (More discussion of how the coatings themselves are maintained is conteined in the paragraphs below.) Other plant nrograms (" Conduct of Operations" and " Ownership of Plant Operating Spaces") ensure that aggressive conditions such as pooled water are not allowed to remain for extended time periods and thus these programs limit the amount of time that piping supports would be subjected to such conditions.

As discussed previously, the level of aging management activity needed for discovery for each category of component supports is determined based on the condition observed during a baseline walkdown of a representative sample of supports of each category. Therefore, discovery activities are discussed in two

categories, baseline activities and follow-on aging management activities. He as-found condition during j the baseline walkdown dictates the level of follow-on aging management needed for the support type.

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, Baseline Walkdowns. Periodic in-service inspection activities serve as an adequate baseline activity to document the condition of piping supports for 12 of the 20 systems within the scope of license renewal which contain these types of supports. The ASME Sect %n XI ISI for component supports includes a visual examination of a prescribed sampling of piping supports in the 12 systems covered by this program. The visual examination contains the following elements which would detect the effects of excessive general corrosion in a timely manner: 1) a visual examinat%n to determine the general mechanical and structural condition of the support and 2) a check for loose parts, debris, abnormal corraion products, wear, erosion, corrosion and loss of irdegrity of bolted or welded connectior.s. ASME Section XI ISI includes the following additional

elements that ensurt that excessive loading, regardless ofits cause, is discovered in a timely

) manner: 1) measurement of clearances,2) detection of physical displacement,3) structural adequacy of supporting elements,4) cor.nectic,ns between load-carrying structural members and 4 s) tightness of bolting. ASME Section XI ISI also contains acceptance criteria which require corrective action if the effects of significant aging are discovered.

Eight of the systems within the scope oflicense renewal, which contain piping supports, are not addressed by IST inspections. Thue systems are: Well and Pretreated Water, Fire Protection, Compressed Air, Diesel Fuel Oil, Plant Heating, Demineralized Water and Condensate Storage, NSSS Sampling System, and Condensate System. Due to the diversity in loading conditions affecting piping systems, a conclusion cou'd not be reached that the piping systems which are inspected by the ISI activities are fully represen'ative of those that have not been inspected by this baseline activity. Therefore, additionr.1 sampling baseline walkdowns will be performed. These walkdowns will consist of a sampling of the supports within the scope oflicense renewal for the eight systems listed above. The sample size will be comparable to the sample size required by A SME Section XI for piping supports of ASME Class 3 systems. The additional walkdowns will execute those steps of the ASME Section XI ISI inspections which are relied upon to detect -

general corrosion and loading due to excessive thermal expansion, hydraulic vibration oc sher loading as described above. These walkdowns will document tiv condition of the piping supports within the scope oflicense renewal and within this component sun ort type for the eight systems listed above. Once these additional walkdowns are completed, an adequate baseiine condition assessment will have been completed for the entire group of supports.

Follow-on Activities. Based on the results of baseline inspections completed per the Ating ISI requirements, it was determined that continuing ASME Section XI ISI inspections int . e period of extended operations will also serve as an adequate follow-on activity for those piping, systems subject to that program.

ASME 5ection XI !S1 of Wing supports is conducted at periodic intervals such that all piping supports of code class systems are inspected on a sampling basis once per inspection interval.

Inrpection intervals are established based on the requirements of an established industry code (i.e.

ASME Sectim XI). He current inspection inter ~al for CCNPP is every 10 years. Because this program is o nducted at periodic intervals, and because of the program elements mentioned under 9

_ _ _ - - - - - - - ~_. - -- - - - . - - -

1 For LR Tcchnical Report Templite Devel;pment July 25,1996 baseline activities above, ASME Section XI ISI of piping supports is also an adequate on-going

> aging management program for the piping supports within the scope of this program.

For piping suppons not covered by ISI requirements, the results of the additional baseline 1

walkdowns described above will determine the extent of aging management practices needed for these supports. If the baseline walkdowns reveal no significant effects of aging, then the follow-on activities for aging management of these piping supports will be system engineer walkdowns af their assigned systems. 'Ihese walkdowns, conducted in accordance with a Plant Engineering fluideline entitled " System Walkdowns," are adequate aging management activities for the

- following reasons:

e Walkdowns are conducted at periodic intervals, normally monthly or as negotiated with each

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system engineer's supervisor. 1 i e Walkdowns are performed by the assigned system engineer, who is familiar with the system and its condition. Any signs of corrosion or excessive loading would be detected by this individual.

• To assist the system engineer in detecting such conditions, the " System Walkdown" guideline contains a checklist, which contains items related to aging of piping supports, on which to document conditions observed during the walkdown.

1 e As a further aid to systems engineers conducting these walkdowns, a Design Engineering Standard entitled " Piping Support Inspections" has been prepared to describe in detail s acceptable and unacceptable conditions of piping supports. Excerpts from this standard are J

included in the system walkdown guideline as an attachment to aid the system engineer.

. The Plant Engineering Guideline on System Walkdowns requires that any unusual condition observed during the system engineer's walkdown of piping suppons be recorded on the walkdown sheet and assistance obtained from design engineering in evaluating the impact of the unusual condition. Conditions that warrant further action are documented on an issue report and the site corrective action program tracks the status of corrective actions.

For snubber suppons an additional follow-on aging management activity is credited. Although the snubbers themselves are determined to be active components in the license renewal rule, the hardware that connects the snubber to the pipe / component and to the structural member are considered passive. Plant Technical Specifications require periodic surveillance of snubbers to ensure functionality. Many of the steps of this surveillance address the functionality of the active snubber and are not credited as aging management activities in the context of the license renewal rule. However, several steps of the surveillance also address the passive snubber supports. The surveillance requires verification that snubber installation exhibits no signs of detachment from foundation or supporting structures including clamps, welds, Hilti bolts, general condition of concrete as well as steps to verify that pipe clamp / rod eye bracket is in satisfactory condition and .

the snubber is properly aligned. Any abnormal condition discovered during this surveillance must be reported and resolved in accordance with the site issue reporting and corrective action process.

These steps of the periodic surveillance will provide funher assurance that aging from general corrosion and excessive loading will be detected prior to loss ofintended function.

Pinine Sunnorts - Demonstration. Based on the factors presented above, the following con:lusions can be reached with resp t to the piping supports for piping systems within the scope oflicense rer,ewal;

• Piping supports associated with piping in the scope oflicense renewal are themselves considered to be within the scope oflicense renewal because failure of these supports could lead to failure of the supponed component.

. General corrosion, loading due to hydraulic vibration, loading due to thermal expansion and other loading (abuse, impacts, accidents) were determined to bc plausible ARDMs for piping supports. The effects of these ARDMs are loss of strength of the piping support and * >sened threaded fasteners in the load bearing path. These effects, ifleft unmanaged, could lead to , u ie intended function of 10

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, , l For LR Technical Report Template D;v;lopment July 25,1996 the piping supports and ultimately to failure of the supported piping under normal or more severe loading conditions.  !

• Two plant programs (" Conduct of Operations" and " Ownership of Plant Operating Spaces") mitigate the effects of corrosion by ensuring that conditions that might accelerate corrosion are not allowed to l continue for extended time periods.  !

• Baseline discovery programs include elements which would enable these activities to discover the  ;

effect of all plausible aging mechanisms and to determine the appropriate level of follow-on aging l management activities. All piping supports within the scope oflicense renewal have either been )

inspected under the existing ASME Section XI In-Service Inspection program baseline activity or will 1 be inspected using similar techniques and standards to establish a baseline condition for license i renewal. The baseline activities conducted to date for a wide range of piping systems have revealed no significant aging effects which require more specialized aging management practices.

• ASME Section XI In-Service inspections, System Engineer Walkdowns and the Snubber Surveillance Inspections are credited as follow-on discovery activities which are conducted at periodic intervals.

These activities include elements which would ensure discovery of the effects of all plausible aging mechanisms end require corrective action and actions to prevent recurrence of problem conditions as appropriate. All piping supports within the scope oflicense renewal are subject to one or more of these follow-on discovery activities.

• The discovery aging management activities (Section XI inspections, additional baseline walkdowns of selected piping systems, system engineer walkdowns and snubber surveillances) detect and correct any adverse effects of general corrosion and loading-related ARDMs well before these ARDMs would have an impact on the intended support function of the piping supports under normal or more severe loading conditions.

• Therefore, there is reasonable assurance that the effects of aging will be adequately managed such that the piping st.pports will be capable of performing their structurt! support function consistent with the CLB during the period of extended operations.

CABLE RACEWAY SUPPORTS [Later]

IIVAC DUCTING SUPPORTS [Later]

EQUIPMENT SUPPORTS A wide variety of equipment suppons are used to provide support for components within the scope oflicense .

renewal. During the aging management review, equipment suppons were divided into eight groups depending on  !

the type of equipment supponed. These groups were based on the method of grouping 4pment supports for the Seismic Qualification Utility Group (SQUG) walkdowns as described in the SQUG Generic Implementation Procedure for Seismic Verification of Nuclear Plant Equipment. Four of these eight groups were further subdivided into supports inside and outside containment since the environment in containment is typically more severe for aging and provides fewer opponunities for routine discovery of degraded conditions. Table 7.6-3 shows the resulting twelve groups of equipment supports. Even though the AMR evaluated suppons inside containment in a i separate group from suppons outside containment, the conclusions of the evaluation were the same for both types of supports with one exception. Therefore, the discussion below addresses the eight types of suppons separately but ]

covers suppons inside and outside containment in the same discussion. Conclusions that do not apply equally to  !

both environraents are addressed as exceptions. I Anchorage including Elastomer Vibration Isolators [Later] )

I Electrical Cabinet Anchorages [Later]  !

Electrical Supports Which llave Load Bearing Insulation Material [Later]

Equipment Frames for Instruments and Batteries on Racks [Later]

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For LR Technic:1 Report Template Devel:pment July 25,1996 Frames and Saddles (Tanks and Ileat Exchangers) This group includes suppons for all SQUG class 21 components (i.e. tanks and heat exchangers) which use frame and/or saddle type supports both inside and outride containment except for the spent fuel pool cooling demineralizer and filter vessel. The suppons for the spent fuel pool cooling demineralizer and filter vessel are in high radiation areas, are not accessible for routine inspections or walkdowns, and could be subject to boric acid corrosion if leakage occurs from the filter vessel or demineralizer.

Therefore, the supports for these components are addressed separately in the LRA Section addressing the Spent Fuel Pool Cooling System.

frames and Saddles (Tanks and Heat Exchangers)- Materials and Environment. Frame and saddle type supports for tanks and heat exchangers are constructed of structural steel (typically carbon steel) and are located inside containment and other climate controlled buildings.

Frames and Saddles (Tanks and Heat Exchangers)- Plausible Aging Mechanisms and Effects on Intended Functions. As shown in Table 7-6.3, general corrosion, loading due to hydraulic vibration, loading due to thermal expansion and other loading (abuse, impacts, accidents) are the ARDMs considered to be plausible for these suppons.

General corrosion is plausible for all equipment supports because normal humidity levels in the plant could result in moisture coming into contact with the structural steel supports. During the plausibility determination, no credit is taken for the protective paint coating applied to these supports; however, this protective coating plays an important role in the aging management approach.

Loading due to hydraulic vibration and thermal expansion is considered plausible for frame and saddle type supports for tanks and heat exchangers. Frame and saddle type supports for tanks and heat exchangers are designed to accommodate a broad range ofloading conditions. However, over time normal and off-normal loading could result in degraded support conditions.

Other loading (abuse, impacts, accidents) was determined to be a plausible ARDM for all frame and saddle type supports for tanks and heat exchangers outside of containment. Equipment inside containment is accessible for a much shorter time period than similar systems outside of containment. Additionally, containment closcout inspections prior to restart would discover any degraded conditions of supports inside containment prior to operating the system at power. Consequently, this ARDM wu detennined to be not plausible for supports inside containment.

Stress corrosion cracking (SCC) of suppon bolting was determined to be not plausible, both inside and outside of containment. Industry experience has shown that high strength botting (i.e. those with yield strength greater than 150 KSI) installed in some NSSS applications inside containment could be subject to stress corrosion cracking in a humid environment. However, the conclusion has been reached that-there is no high strength bolting installed in frame and saddle type supports for tanks and heat exchangers at CCNPP for the following reasons -

• Industry experience with SCC of high strength bolting in a humid environment has shown that such high strength bolting is likely to fail in a matter of months after installation.

. Such failures would have been discovered and corrected during the routine plant operations and maintenance activities including the baseline discovery activities discussed in the following paragraphs.

• Additionally, plant construction practices would have made it highly unlikely that high strength bolting would be installed in component support applications during plant construction even though equipment specifications typically did not place an upper limit on bolting strength.

• Current design standards for suppons do contain guidance on bolting materials to be used for equipment suppons.

Because the conclusion has been reached that there is no high strength bolting in frame and saddle type supports for tanks and heat exchangers, SCC was determined tc be not plausible for these supports.

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a Fcr LR Technical Report Templ:te D velopmtnt July 25,1996

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The effects of general corrosion on frame and saddle type supports for tanks and heat exchangers would be- l a loss of support material and consequently a reduction in component support strength if the ARDM were l allowed to progress unmanaged. The effects of loading due to hydraulic vibrations, thermal expansion and l other loading would initially be loosened or broken threaded fasteners, cracking of concrete adjacent to anchor bolts and/or physical deformation of the supports themselves. If these mechanisms were left I unmanaged, the effects could progress to the point of reducing the amount of support afforded to the tanks or heat exchangers and/or allowing excessive motion of the supported component. This failure of the i supports' intended function could, in turn, lead to failure of the tank or heat exchanger pressure boundary under normal or more severe loading conditions.

Frames and Saddles (Tanks and Heat Exchangersh Methods to Manage the ARDMs. Methods to manage aging of the frame and saddle type supports for tanks and heat exchangers are discussed in two categories.  !

Mitigation measures are activities which reduce the likelihood or rate of the ARDMs. Discovery I techniques are those that can reasonably detect the effects of aging prior to loss ofintended function.

]

To mitigate the effects of general corrosion, the conditions on the external surfaces of the suppons must be controlled. Significant rates of corrosion related ARDMs only occur when simports come into contact with f moisture. Preventing direct and prolonged contact between metal surfaces and moisture is an effective ,

mitigation technique for general corrosion. For mitigation of the other plausible ARDMs, support design i requirements in accordance with original plant specifications require that the supports accommodate a

)

l broad range of loadi ; conditions. Any system modifications which involve the supports also account for j a range ofloading a m 'itions equivalent to that required by the initial design specifications. 1 i

The effects of the general corrosion are detectable by visual techniques. Because much of the external l metal surfaces of the frame and saddle type suppons for tanks and heat exchangers are covered by a l protective coating (paint), observing that significant degradation has not occurred to this coating is an l effective method to ensure that corrosion has not affected the intended function of the suppons. Because

the paint does not contribute to the intended function of the supports, observing the paint for degradation provides an alert condition which would trigger corrective action before degradation of the support's ability to perform its intended function. The effects of excessive loading from thermal expansion, hydraulic vibrations or other loading (abuses, impacts, accidents) are observable initially in the form ofloosened or l

broken threaded fasteners and/or physical deformation of the supports themselves. Therefore, adequate discovery techniques for aging of this type of supports need to include both a visual observat ion of the general condition of the suppons to address general corrosion and observation of the supports for physical j deformation, loose parts, loosened fasteners and adequate tightness of bolting to address the loading-related ARDMs.

Frames and Saddles (Tanks and Heat Exchancersb Identification and Descrintion of Aging Management Programs. A combination of mitigation and discovery methods are implemented in CCNPP programs and activities to manage the effects of aging on the intended function of frame and saddle type suppons for tanks and heat exchangers. The plant programs and activities described below apply to all frame and saddle type supports for tanks and heat exchangers within the scope oflicense renewal with the exceptions j l noted.

A combination of plant programs and activities ensure that the external metal surfaces of these supports are ,

not in contact with a moist, aggressive environment. One program preserves the protective coating (paint) l

, which covers much of the support and serves as an effective measure to mitigate the onset of general corrosion. (More discussion of how the coatings themselves are maintained is contained in the paragraphs below.) Other plant programs (" Conduct of Operations" and " Owr:rship of Plant Operating Spaces") I ensure that aggressive conditions such as pooled water are not allowed to remain for extended time periods

and thus these programs limit the amount of time that frame and saddle type supports for tanks and heat exchangers would be subjected to such conditions. ]

I 13 4

Fer LR Technicil Report Templite DevelopmInt July 25,1996 As discussed previously, the level of aging management activity needed for discovery for each group of component suppons is determined based on the condition observed during a baseline walkdown of a representative sample of supports of that group. Therefore, discovery activities are discussed in two categories, baseline activities and follow-on aging management activities. The as-found condition during the baseline walkdown dictates the level of follow-on aging management needed for the support type.

Baseline Walkdowns. The Seismic Verification Project (SVP) was established at Calvert Cliffs Nuclear Power Plant (CCNPP) to resolve Unresolved Safety Issue A-46 related to the seismic adequacy of older nuclear power plants. The SVP used the NRC-approved Generic Implementation Procedure to verify the seismic adequacy of equipment required for safe shutdown following a seismic event. Even though the project was established for other pmposes, it is credited as a baseline inspection for frame and saddle type supports for tanks and heat exchangers for license renewal.

Tank and heat exchanger supports for a representative sample of the systems within the scope of license renewal were included in the SVP. Frame and saddle type supports for tanks and heat exchanger which were included in these baseline inspections include supports for the following:

service water head tank and heat exchangers (HX), spent fuel pooling cooling HXs, ECCS room air coolers, component cooling water (CCW) head tank and HXs, containment penetration coolers, CCW chemical addition tanks, compressed air system accumulators and receivers, emergency diesel generator tanks and accumulators, boric acid storage tanks, volume control tank, letdown HX, shutdown cooling HX, regenerative HX, quench tank and steam generator support coolers. Frame and saddle type supports for tanks and heat exchangers which were not includeci in a baseline inspection are the waste gas tanks, hydrogen recombiners and safety injection tanks.

The supports for these tanks and heat exchangers are similar in design, materials and environment to those that were included in the SVP. Therefore, no additional baseline activities are required to determine the type of follow-on aging management activity needed for these supports.

The SVP used the Seismic Qualification Utility Group methodology, whose acceptance criteria are based on the as-found condition of equipment and raceways in over 80 industrial facilities that have experienced strong-motion earthquakes. The average age of these facilities at the time of their assessment was 22 years, with 11 of these facilities being over 40 years old at the time of their assessment. Many equipment items and raceways in this datalese had already been subject to significant aging and still survived large seismic loadings with no significant damage. The Generic Implementation Procedure acceptance criteria are specifically based on the features or i conditions of damaged equipment or raceways in the database that caused them to be more structurally vulnerable than similar equipment that was not damaged. Based on this experience database, significant emphasis is placed on confirming the structural adequacy and the as-found condition of equipment suppert load paths and anchorages. 'Ihe SVP inspections examine equipment supports for load path degradation (such as grout / concrete local deterioration potentially caused by loadings from rotating / reciprocating machinery, hydraulic vibration or water hammer, and thermal expansion of piping / components), general corrosion of steel and signs of abuse, impacts, and accidents. Any equipment support found that did not meet the Generic Implementation Procedure criteria (and therefore might not be able to perfonn its intended function under all design conditions) was documented as an " outlier" and evaluated further to duermine what, if any, corrective action or modification was needed to resolve the concern.

Because they address a representative sample of all frame and saddle type supports for tanks and j heat exchangers and because these inspections are capable of detecting the effects of all plausible aging mechanisms, the SVP walkdowns are considered to be an adequate baseline inspection, for all supports in this group.

Follow-On Activities. Based on the fact that no significant aging effects were discovered during the baseline walkdowns completed per the SVP project, the follow-on aging management 14

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1 For LR Tcchnicil Report Template D:valopment July 25,1996 l

activities will consist of system engineer walkdowns of their assigned systems. These walkdowns, conducted in accordance with the Plant Engineering Guideline entitled " System Walkdowns," are adequate aging management activities for the following reasons:

!

• Walkdowns are conducted at periodic intervals, normally monthly or as negotiated with each system engineer's supervisor.

l i l . Walkdowns are performed by the assigned system engineer who is familiar with the system

( and its condition. Any signs of corrosion or excessive loading on tank or heat exchanger l supports would be detected by this individual. To provide additional assurance that these walkdowns would discover such degradation, the System Walkdown Guideline' specifies that periodically a focused inspection of equipment anchorages be included in conjunction with the routine system walkdown.

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• To assist the system engineer in detecting such conditions the " System Walkdown" guideline l contains a checklist, which contains items related to aging of equipment suppo ts, to document conditions observed during the walkdown.

. The Plant Engineering Guideline on System Walkdowns requires that any unusual condition observed during the system enginec's walkdown (including unusual conditions of frame and saddle type supports for tanks and heat exchangers) be recorded on the walkdown sheet and assistance obtained from design engineering in evaluating the impact of the unusual l

condition. Conditions that warrant further action are documented on an issue report and the site corrective action program tracks the status of corrective actions.

l Frames and Saddles (Tanks and Heat Exchangers)- Demonstration. Based on the factors presented above, l the following conclusions can be reached with respect to the frame and saddle type supports for tanks and heat exchangers within the scope oflicense renewal (with the exception of the spent fuel pool cooling 1

demineralizer and filter vessel):

i

. Frame and saddle type supports associated with tanks and heat exchangers in the scope of license l

! renewal are themselves considered to be within the scope oflicense renewal because failure of these

! supports could lead to failure of the supported component.

. General corrosion, loading due to hydraulic vibration, loading due to thennal expansion and other ,

loading (abuse, impacts, accidents) were determined to be plausible ARDMs for these supports. The effects of these ARDMs are loss of strength of the equipment support, loosened or broken threaded fasteners in the load bearing path, cracking of concrete adjacent to anchor bolts and/or physical deformation of the supports themselves: These effects, ifleft unmanaged, could lead to loss of the intended function of the frame and saddle type supports and ultimately to failure of the supported tank or heat exchanger under normal or more severe loading conditions. )

• Two plant programs (" Conduct of Operations" and " Ownership of Plant Operating Spaces") mitigate the effects of corrosion by ensuring that conditions that might accelerate corrosion are not allowed to continue for extended time periods, e Baseline discovery activities (SVP inspections) include elements which would enable these activities to discover the effect of all plausible aging mechanisms and to determine the appropriate level of follow-on aging management activities. A representative sample of frame and saddle type supports for

, tanks and heat exchangers within the scope oflicense renewal have been inspected under the Seismic l Verification Project. These inspections have revealed no significant aging effects which require more specialized aging management practices.

• Follow-on discovery activitics (system engineer walkdowns) are conducted at periodic intervals. .

These activities include elements which would ensure discovery of the effects of all plausible aging l mechanisms and require corrective action and actions to prevent recurrence of problem conditions as  ;

appropriate. All frame and saddle type supports for tanks and heat exchangers within the scope of l license renewal are subject to these follow-on discovery activities. I

e ne discovery aging management activities (SVP and system engineer walkdowns) detect and correct l any adverse effects of genera! corrosion and loading-related ARDMs well before these ARDMs would i

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f For LR Technic:1 Report Templ:te Development July 25,1996  !

l l Therefore, there is reasonable assurance that the effects of aging will be adequately managed such that l the frame and saddle type supports for tanks and heat exchangers will be capable of perfonning their structural support function consistent with the CLB during the period of extended operations.

Metal Spring isolators and Fixed Bases [LaterJ LOCA Restraints (e.g., pressurizer and reactor coolant pump supports)[LaterJ l Ring Foundations for Flat-Bottom Vertical Tanks [LaterJ Conclusion The programs discussed for aging management of component supports are summarized in the following table.

These programs are administratively controlled by a formal review and approval process. As demonstrated above, there is reasonable assurance that these programs will manage the effects of aging such that the intended function of the Component Supports within the scope oflicense renewal will be maintained consistent with the CLB during the l period of extended operations. j Table 7.6-4 List of Acine Management Procrams for Component Supports l

Program Name Credited As l Conduct of Operations and Ownership of Plant Spaces Mitigation program to ensure that environments which might accelerate aging of component supports are not allowed to be present for extended time period.

Section XI in Service Inspection of Piping Supports Baseline discovery activity for all piping systems within the scope oflicense renewal except the eight systems mentioned. l Additional Baseline Walkdowns of the portions of eight Baseline discovery activity for the in-scope portions of l piping systems within the scope oflicense renewal. the Well and Pretreated Water, Fire Protection, Compressed Air, Diesel Fuel Oil, Plant Heating,

! Demineralized Water and Condensate Storage, NSSS Sampling, and Condensate Systems l Seismic Verification Project Walkdowns Baseline discovery activity for all frame and saddle type I

supports for tanks and heat exchangers within the scope j l oflicense renewal with the exception of the spent fuel j

! pool cooling demineralizers and filter vessels. These supports are covered by a separate AMR. i Section XI in Service Inspection of Piping Supports Follow-on discovery activity for those systerns covered by this program.  ;

l Plant Engineering Guideline on System Walkdowns Follow-on discovery activity for those piping systems i l not covered by the Section XI ISI program and all frame l and saddle type supports for tanks and heat exchangers l within the scope oflicense renewal.

Snubber Surveillance Procedure Follow-on discovery activity for snubber supports within the scope of this commodity evaluation.

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1o For LR Technical Report Templ:te DIvel pmeat July 25,1996 REFERENCES 1.

"Calvert Cliffs Nuclear Power Plant Units I and 2, Aging Management Review of Component Supports,"

September 1995

2. CCNPP Updated Final Safety Analysis Report, Revision 19

3. Generic Implementation Procedure (GIP) for Seismic Verification of Nuclear Plant equipment Dated Febmary 1992, copyright Seismic Qualification Utility Group (SQUG), Revision 2, corrected February 14, 1992

4. ASME Boiler and Pressure Vessel Code Section XI," Rules for in-Service Inspection of Nuclear Power Plant Components," 1983 edition with Addenda through Summer 1983

5. PEG-7," Plant Engineering Section Guideline, System Walkdowns," Revision 4, November 1995 i

6. STP-M-12-1. " Unit 1 Accessible Snubber Visual inspection," Revision 12, January 3,1996

7. STP-M-12-2," Unit 2 Accessible Snubber Visual Inspection," Revision 14, January 3,1996

8. STP-M-13-1, " Unit i Inaccessible Snubber Visual Inspection," Revision 15, January 3,1996

9. STP-M-13-2," Unit 2 Snubber inspection (Inaccessible)," Revision 13, January 3,1996 l

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