ML20010E473

Proposed Revised Tech Specs Pages 3/4 & 6.10.2 Re Snubber Surveillance Requirements

ML20010E473
Person / Time
Site:	Sequoyah
Issue date:	08/28/1981
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20010E471	List: ML20010E470 ML20010E473
References
NUDOCS 8109040162
Download: ML20010E473 (14)

Text

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L ENCLOSURE o . SEQUOYAH NUCLEAR PLANT PROPOSED TECHNICAL SPECIFICATION PLANT SYSTEMS 3/4.7.9 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.9 All safety-related snubbers shall be OPERABLE. The snubbers are shown in Tables 3.7-4a and 3.7-4b and are listed in Surveillance Instruction SNE SI-162. Any exemptions to the surveillance program are shown in Table 3.7-4c and in SNP SI-162.

APPLICABILITY: Modes 1, 2, 3, and 4. (Modes 5 and 6 for snubbers located on systems or partial systems required OPERABLE in these Modes.)

ACTION: With one or more snubbers inoperable, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> replace or restore the inoperable snubber (s) to OPERABLE status and perform an engineering evaluation on the attached component or declare the attached system inoperable and follow the appropriate ACTION statement for that system.

SURVEILLANCE REQUIREMENTS 4.7.9 Each safety-related snubber shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program and the requirements of Specification 4.0.5. These snubbers are shown in Tables 3.7-4a and 3.7-4b and are listeo in Surveillance Instruction SNP SI-162. Table 3.7-4b is a detailed tabulation of the hydraulic snubbers which are also shown in Table 3.7-4a Any exemptien to any portion of the surveillance program for any snubber is shown in Table 3.7-4c

a. Inspection Groups The snubbers may be categorized into two major groups based on whether the snubbers are accessible or inaccessible during reactor operation. These major groups may be further subdivided into subgroups based on design, environmeut, or other features which may be expected to affect the OPERABILITY of the snubbers

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within the subgroup. Each subgroup or group may be inspected independently in accordance with 4.7.9.b through 4.7.9.h.

b. Visual Inspection Schedule and Lot Size '-

The first inservice visual inspection of snubbers shall be completed by October 31, 1981, and shall include all' snubbers on safety-related systems. If less than two (2) snubbers are found

,c SEQUOYAH - UNIT 1 .3/4 7-22 8109040162 810828 PDR ADOCK 05000327 p PDR

PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

b. Visual Inspection Schedule and Lot Size (Cont'd) inoperable during the first inservice visual inspection, the second inservice visual inspection shall be performed 12 months i 25% from the date of the first inspection. Otherwise, subsequent visual inspections shall be performed in accordance with the following schedule:

Number of Inoperable Subsequent Visual Snubbers per Inspection Inspection Period * #

Period 0 18 months 25%

1 12 months 25%

2 6 months 1 25%

3, 4 124 days 25%

5,6,7 62 days 1 25%

8 or more 31 days 25%

c. Visual Inspection Performance and Evaluation Vinual inspections shall verify (1) that there are no visible indications of damage or impaired OPERABILITY, (2) bolts attaching the snubber to the foundation or supporting structure are secure, and (3) snubbers attached to sections of safety-related systems that have experienced unexpected potentially damaging transients since the last inspection period shall be evaluated for the possibility of concealed damage and functionally tested, if applicabic, to confirm operability.

i Snubbers which appear inoperable as a result of visual inspections may be determined OPERABLE for the purpose of establishing the next visual inspection interval, providing that (1) the cause i

of the rejection is clearly established and remedied for that particular snubber and for other snubbers that may be generically susceptible; and (2) the affected snubber is functionally tested, if applicable, in the as-found condition and determined OPERABLE per Specification 4.7.9.e. Hydraulic snubbers with inoperable single or common fluid reservoirs which have uncovered fluid ports shall be declared inoperable. When hydraulic snubbers which have uncovered fluid ports are tested, the tests shall bes performed by starting with the piston at the as-found setting and extending the piston rod in the excension mode direction.

w The inspection interval shall not be lengthened more than one ste p at a time.

1. The provisions of Specification 4.0.2 are not applicable.

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i SURVEILLANCE REQUIREMENTS (Continued) i

, c. Visua: Inspection Performance and Evaluation (Cont'd)

Also, snubbers which'have been made inoperable as the result'

{ of unexpected transients, isolated damage or other such randca events, when the provisions of 4.7.9.g and 4.7.9.h have been iet and any other appropriate corrective action implemented, .

shall not be counted in determining the next visual inspection interval.

1 i d. Functional Test Schedule, Lot Size, and Composition During each refueling outage a representative sample of 10% of I

the total of the safety related snubbers in use in the plant.

shall be functionally tested either in place or in a bench test.

The representative sample selected for functional testing shall include the various configurations, operating environments, and-a the range of size and capacity of snubbers within the groups or subgroups. The representative sample should be weighted to include more snubbers from severe service areas such as near

heavy equipment. Unless' a failure analysis as required by i

4.7.9.f indicates otherwice, the sample shall be a composite.

l based on the ratio of each group to the total number of snubbers i

installed in the plant. Snubbers placed in the same location as snubbers which failed the previous functional test shall be included in the next test lot if the failure analysis shows j that failura was due to location.

l' The security of fasteners for attachment of the snubbers to the component and to the snubber anchorage shall be verified on i

snubbers selected for functional tests.

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e. Functional Test Acceptance Criteria 4

The snubber functional test shall verify that:

1. Activation (restraining action) is-achieved within the specified range in .both tension and compression, except that inertia dependent, acceleration limiting mechanical snubbers may be tested to verify only that activation -

takes place in both directions of travel.

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PLANT SYSTEMS SURVEILLANCE REQUIREMF"TS (Continued)

2. Snubber bleed, or release where required, is present in both tension and compression, within the specified range.

3. The force required to initiate or maintain motion of the snubber is within the specified range in both directions of travel. Also, the increase in the force required shall not exceed 50 percent of the amount required at the last surveillance test of that snubber, provided that the force required is at least 25 pounds.

4. For snubbers specifically required not to displace under continuous load, the ability of the snubber to withstand load without displacement shall be verified.

5. Testing methods may be used to measure parameters indirectly or parameters other than those specified if those results can be correlated to the specified parameters through established methods.

f. Functional Test Failure Analysis and Additional Test Lots If any so aber selected for functional testing either fails to lock up . - fails to move due to manufacture or design deficiency, all snub ers of the same design subject to the same defect shall be functionally tested.

If more than two snubbers do not meet the functional test acceptance criteria, an additional lot equal to one-half the original lot size shall be functionally tested for each

! failed snubber in excess of the two allowed failures.

i An engineering evaluation shall be made of each failure to

meet the functional test acceptance criteria to determine I the cause of the failure. The result of this analysis shall be used, if applicable, in selecting snubbers to be tested in the subsequent lot in an effort to determine

, the operability of other snubbers which may be subject I to the same failure mode. (Selection of snubbers for future

i. testing may also be based on the failure analysis.) '

Testing shall continue until not more than one additional-l inoperable snubber is found within a subsequent required lot i

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PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

f. Functional Test Failure Analysis and Additional Test Lots (Cont'd) or all snubbers of the original inspection group have been tested, or all suspect snubbers identified by the failure analysis have been tested, as applicable.

The discovery of loose or missing attachment fasteners will be evaluated to determine whether the cause may be localized or generic.

The result of the evaluation will be used to select other suspect snubbers for verifying the attachment fasteners, as applicable.

Snubbers shall not be subjected to prior maintenance specifically for the purpose of meeting functional test requirements,

g. Functional Test Failure --Attached Component Analysis For snubber (s) found inoperable, an engineering evaluation thall be performed on the components which are restrained by the snubber (s).

The purpose of this engineering evaluation shall be to determine if the components restrained by the snubber (s) were adversely affected by the inoperability of the snubbers (s), and in order to ensure that the restrained component remains capable of meeting the designed service.

h. Functional Testing of Repaired and Spare Snubbers Snubbers which fail the visual inspection or the functional test acceptance criteria shall be repaired or replu.ed. Replacement snubbers and snubbers which have repairs which might affect the functional test results shall be tested to meet the functional test criteria before installation in the unit. These snubbers shall have met the acceptance criteria subsequent to their most recent service, and the functional test must have bee.1 performed within 12 months before being installed in the unit.

i. Snubber Service Life Program l

The seal service life of hydraulic snubbers shall be monitored to ensure that the seals do not fail between surveillance -

inspections. The maximum expected service life for the various seals, seal materia 13, and applications shall be estimated based on engineering information, and the seals shall be replactd so that the maximum expected service life does not expire during a period when the snubber is required to be operable. The seal replacements shall be documented and the documentation shall be retained in accordance with 6.10.2.n.

SEQUOYAH - UNIT 1 3/4; 7-26 1:

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SURVEILLANCE REQUIREMENTS (Continued)

I Snubber Service Life Program (Cont'd)

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Mechanical snubber ' drag force increases greater than 50 percent of previously measured values shall be evaluated as an indi-cation of impending failure of the snubber. These evaluations and any associated corrective action shall be documented and the documentation shall be retained in accordance with 4

6.10.2.n.

e j . Exemption From Visual Inspection or Functional Tests i

Permanent or other exemptions from the surveillance program for individual snubbers may be granted by the Commission if a justifiable basis for exemption is presented and if applicable snubber life destructive testing was performed to qualify snubber operability for the applicable design conditions at either the completion of their fa? '.. tion or at a subsequent-l date. Snubbers so exempted shall be listed in Table 3.7-4c and shall continue to be listed in the plant instruction i SNP SI-162 indicating the extent ci the exemptions.

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Table 3.7-4a Safety Related Snubbers *

ACCESSIBLE INACCESSIBLE Small Medium & Large llyd. Small Medium & Large PaufIlyd .

PSA PSA PSA PSA )!unrde l Size 1/4l1/2 1 l3 l 10 35 l 100 1/4'l1/2l 1 l3 10l 35l 100! l-MS l 221 9 3 9 9 7 .12 1 I 20 l 16 AMS 1 2 3 l AFD I 4: 1 1 4 5 1 2 2 2 FD 2 6 1 1 2l 1 l p; 8 10 8 10 21 5 4 2 l l- 4l 6

4 i , i 1

SI I 3 1 2 37 12 2 9 15l 1 1 4 Cs  ! 3 4 2 3- 1 l 15 l 1 l 1 l l

cvC l7 5 1 I: 24 l 7 3 8l 1l l l

RC 15 16 29 h 40 19 l 8 l UHT 1 4 7 l 20 24 b 5 l -l 1l SGB 1 1 1 7 8l5 l l l l l FPC 2 4 3 1l l l l g ERCW 2 5 4 22l19 23 15 b l  ! l l k RHR 5 2 2 6 2 2 1 l l l l 3l TC 8 6 5 l l "l -l UD 9 l l -l l l l DN 1 1 1i l l l l l SE 1 1 1l l l l l' l

[ PW l 2 -1 1 l I l l E &H 12 ~7 l '! l l I -l I l l l

i l Dn1 44 24 19 31 30 11 7 154 86 87 l106 77 15' -

Totalt 68 98 47 240 285- 20 31

• Snubbersimay be added to safety related systems without prior License Amendment to Table 3.7-4a provided that a revision to Table'3.7-4a is included with the ,

I next License Amendment request. Any exemptions to the provisions of the surveillance program for any snubber. ia indicated in Table 3.7-4c.

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$ Table 3. 7-4b S Safety Related liydraulic Snubbers * *

.fj ACCESSIBLE INACCESSIBLE Sub Sub -

Size 1 11; 2 215 314 4 5 6 8 Total Size 1 115 F2 ~ 215 3h 4 'S 6 8 Torn 1 z l l M MS 1 5 5 1 1 17 MS R R I 16

" l n AMS 3 3 AMS I f l AFD 2 3 5 AFD 2 i l 2 FD 3 2 1 l 6 FD l 1 1 CC 1 2 3 3 1 l 10 CC 2 2l l 4 ST 1 1 2 ST i 1 2 1 l 4 CS 1 l 1 1 3 CS l O cyc 4  ! 4 CVC l 0 v RC 0 RC l 0 s.

UHT 0 U11T . 1 l l i 1 w i , , i k

e SGB 0 SGB l i I l. O PC FP.C_ 0 FPC 0 2 2 RHR 2 3 fRHR a:

1 i

. & TC 0 IC i O_

WD 0 im 0 DW 0 DW l 0 SA . O SA l 0

_PW 0 PW 0 AE&H 0 AC&H 0 L

ERCW 0 ERCW O O

j Total 47 Total 31

• Snubbers may be added to safety related systems without prior License Arcendnent to Table 3.7-4a provided that a revision to Tabic 3.7-4a is included with the next License Amendment request. Any exemptions to the provisions of the surveillance. program for any snubber is indicated in Tabic 3.7-4c .

Table 3.7-4c Safety Related Sanbbers - Exemptions to the Surveillance Program i

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PLANT SYSTEMS BASES 3/4.7.8 AUXILIARY BUILDING GAS TREATMENT S STEM The OPERABILITY of the auxiliary building 3as treatment system ensures that radioactive materials leaking from the'ECCS equipment following a LOCA are filtered prior to reaching the environment. The operation of this system and the resultant effect on offsite dosage calculations was assumed in the accident analyses. Cumulative operation of the system with the heaters on for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> over a 31 day period is sufficient to reduce the buildup of moisture on the adsorbers and ilEPA filters. ANSI N510-1975 will be used as a procedural guide for surveillance testing.

3/4.7.9 SNUBBERS i

Snubbers are designed to prevent unrestrained pipe or component motion under dynamic loads as might occur during an earthquake or severe transient, while allowing normal thermal motion during startup and shutdown. .The consequence of an inoperable snubber is an increase in the probability of structural damage to piping or components as a result of a seismic or other event initiating dynamic loads. It is therefore required that all snubbers required to protect the primary coolant system or any other

, safety system or component be operable during reactor operation.

Because the snubber protection is required only during relatively low probability events, a period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed to replace or restore the inoperable snubber (s) to operable status and perform an engineering evaluation on the supported component or declare the supported system-inoperable and follow the appropriate limiting condition for operation i

statement for that system. The engineering evaluation is performed to determine whether the mode of failure of the snubber has adversely aifected any safety-related component or system.

All safety-related snubbers are visually inspected for overall integrity and operability. The inspection will include verification of proper orientation, adequate fluid level if applicable, and attachment of the snubber to its anchorage. The removal of insulation or the verification of torque values for threaded fasteners is not required for visual inspections.

• l The inspection frequency is based upon maintaining a. constant level of snubber protection. Thus, the required inspection interval varies inversely with the observed snubber failures. The number of inoperable '-

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snubbers found during a required inspection determines the time interval for the next required inspection. Inspections performed before that interval has elapsed may be used as a new reference point to determine the next inspection. However, the results of such early inspections performed before the original required time interval has elapsed (nominal time less 25 percent) may not be used to lengthen the required' inspection i

interval. Any inspection.whose results require a shorter inspection interval will override the previous schedule.

SEQUOYAll - UNIT I B 3/4 7-5 .

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Pl. ANT SYSTEf!S i_ LASES 3/4.7.9 SNUBBERS (Cont'd)

When the cause of the rejection of a snubber in a visual inspection is clearly established and remedied for that snubber and for any other snubbers that may be generically susceptible and operability verified by inservice functional testing, i f applicable, that snubber may be exempted from being counted as inoperable. Generically susceptible snubbers are those which are of a specific make or model and have the same design features directly .related to rejection of the snubber, or are similarly located or exposed to the same environmental conditions such as temperature, radiation, and vibration.

Inspection groups may be established based on design features arid installed conditions which may be expected to be generic. Each of these inspection groups are inspected and tested separately unless an engineering 4

analysis indicates the inspection group is improperly constituted. All suspect snubbers are subject to inspection and testing regardless of inspection groupings.

To further increase the assurance of snubber reliability, functional usts shall be performed during each refueling outage. These tests will inclade stroking of the snubbers to verify proper movement, activation, and bleed or release. The performance of hydraulic snubbers generally depends on a clean, deaerated fluid contained within variable pressure chambers, flowing at closely controlled rates. Since these characteristics are subject to change with exposure to the reactor environment., time, and other factors, i

their performance within the specified range should be verified. ?!cchanical snubbers which depend upon overcoming the inertia of a mass and the braking action of a capstan spring contained within the snubber for limiting the acceleration of the at tached component (within the load rating of the snubber) are not subject to changes in performance in the same manner as hydraulic snubbers. Pending the development of information regarding the change during the service of the snubber of the acceleration / resistance relationship and the optimum method for detecting this change, these mechanical snubbers may be tested to verify that when subjected to-a large change in velocity the resistance to moveirent increases greatly. The performance change l information is to be developed in order to establish test methods to be

used during and af ter the first refueling outage. 4 l Ten percent of the total population of approximately 700 snubbers is an i adequate sample for functional tests. The initial sample is to be 4

proportioned among the groups in order to obtain a-representative sample.

Observed failures of more than two snubbers in the initial lot will require i an engineering analysis and testing of additional snubbers selected from snubbers likely t.o have the same defect. A thorough inspection of the i snubber threaded attachments to the pipe or components and the anchorage

i. will be made in conjunction with all required functional tests.

SEQUOYAll UNIT 1 B 3/4 7-6

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3/4.7.10 SEALED SOURCE CONTAMINATION The limitations on removable contamination for sources requiring leak testing, including alpha emitters, based on 10 CFR 70.39(c) limits for plutonium. This limitation will ensure that leakage from byproduct, source, and special nuclear material sources will not exceed allowable intake values. ~ Sealed sources are classified into three groups according to their use, with surveillance requirements commensurate with the probability of damage to a source in that group. Those sources which are frequently handled are required to be tested more often than those which are not. Scaled sources wh!ch are continuously enclose f gaseous and liquid radioJilive material released to the environs.

e Record *. o f tr ansient or nper.it ional cyc les f or those unit componea.t s identified in Table 5.7-1.

f. Records nf reactor tests and esperiments. ,

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Records of training and qualification for current teet.bers of the unit staff, b.

Records of in service inspections performed pursuant to these Technical Specifications. -

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Records of Quality Assurance activities requirea by the Operationcil Quality Assurance Manual, j.

Records o' reviews performed for changes made to procedures or equipment or 1eviews of tests, and experiments pursuant to 10 CFR 50.39.

Records of meetings of the PORC, EARC, and the NSRB.

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Ret.ords of analyse, required by the radiological environmental monitoring program.

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Records of secondary water sanpling and water quality. .

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Records of service life monitoring of all snubbers listed in SI-162 and in Tables 3.7-4a and 3.7-4b including the maintenaace performed o.

to renew service life of the snubbers. '

Records for Environs.iental Qualification which anscovernd under the provisions of Paragraph ?.C.(l?)(b) of License No. DPR'77 (s. I 1 i

RADIAT10:1 PROTf.CT10il PROGRAM

'*roct. dure. for personnel radiat ion protection shall be prepared consist ent with the requirements of 10 CfR Part 20 and shall he approved . rnaintained and adher2d to for all operations involving personori radia t ion c posure.

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