ML20010F964

Proposed Tech Specs 3/4.7.10 Re Snubbers & 6.10.2 Re Admininstrative Controls for Unit 2.Discussion of Proposed Supplemental Tech Spec Change Encl

ML20010F964
Person / Time
Site:	North Anna
Issue date:	09/10/1981
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20010F958	List: ML20010F957 ML20010F959 ML20010F964
References
NUDOCS 8109150165
Download: ML20010F964 (8)

Text

PLANT SYSTEMS 3/4.7.10 SNUBBERS LIMITING CONDITION FOR OPERATION 3.7.10 All snubbers listed..in Tables 3.7-4a and 3.7-4b shall be OPERABLE. l APPLICABILITY: MODES 1, 2, 3 and 4. (MODES 5 and 6 for snubbers located on systems required OPERABLE in those 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 per Specification 4.7.10.c on the supported component or declare the supported system inoperable and follow the appropriate ACTION statement for that system.

SURVEILLANCE REQUIREMENTS 4.7.10 Each snubber shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program and the requirements of Specification 4.0.5.

a. Visual Inspections The first inservice visual inspection of snubbers shall be performed after four months but within 10 months of commencing POWER OPERATION and shall include all snubbers listed in Tables 3.7-4a and 3.7-4b.

If less than two (2) snubbers are found 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:

No. Inoperable Snubbers Subsequent Visual per Inspection Period Inspection Period *y 0 18 months 1 25% _

l 1 12 months i 25%

l 2 6 months i 25%

3,4 124 days i 25%

5,6,7 62 days i 25%

8 or more 31 days i 25%

The snubbers may be categorized into two groups: Those accessible I and those inaccessible during reactor operation. Each group may be inspected independently in accordance with the above schedule.

l g The inspection interval shall not be lenthened more than one step at a time.

l The provisions of Specification 4.0.2 are not applicable.

l NORTH ANNA - UNIT 2 3/4 7-25 l 8109150165 810910 PDR ADOCA 05000338 P PDR

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PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

b. Visual Inspection Acceptance Criteria Visual inspections shall verify (1) that there are no visual indica-tions of damage or impaired OPERABILITY, (2) attachments to the foundatior, or supporting structure are secure, and (3) in those locations where t,nubber movement can be mar.ually induced without disconnecting the snubber, that the snubber has freedom of movement and is not frozen up. 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 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 in the as found condition and determined OPERABLE per Specifi-cations 4.7.10.d and 4.7.10.e. However, when the fluid port of a hydraulic snubber is found to be uncovered, the snubber shall be determined inoperable and cannot be determined OPERABLE via functional testing for the purpose of establishing the next visual inspection ir.terval . All snubbers connected to an inoperable common hydraulic fluid reservior shall be counted as inoperable snubbers.

c. Functional Tests At least once per 18 months during shutdown, a representative sapple ofthatnumberofsnubberswhichfollowstheexpression35[1+j],

where c=2 is the allowable number of snubbers not meeting the acceptance criteria selected by the operator, shall be functionally tested either in place or in a bench test. For each number of snubbers above c which does not meet the functional test acceptance criteria of Specification 4.7.10.d or 4.7.10.e, and additional sample selectedaccordingtotheexpression35(1+[)(cf1)2(a-c) shall be functionally tested, where a is the total number of snubbers found inoperable during the functional testing of the representative sample.

Functional testing shall continue according to the expression b[35(1+{)2]wherebisthenumberofsnubbersfound inoperable in the previous re-sample, until no additional inoperable snubbers are found within a sample or until all snubbers in Table 3.7-4e and 3.7-4b have been functionally tested.

NORTH ANNA - UNIT 2 3/4 7-26a

PLANT SYSTEMS SURVEILLANCF REQUIREMENTS (Continued)

The representative sample selected for functional testing shall include the various configurations, operating environments and the range of size and , capacity of snubbers. At least 25% of the snubbers in the representative sample shall include snubbers from the following three categories:

1. The first r.nubber away from each reactor vessel nozzle

2. Snubbers within 5 feet of heavy equipment (valve, pump, turbine, motor,etc.).

3. Snubbers within 10 feet of the discharge from a safety relief valve.

Snubbers identified in Tables 3.7-4a and 3.7-4b as "Especially Difficult to Remove" or in "High Radiation Zones During Shutdown" shall also be included in the representative sample.* Tables 3.7-4a and 3.7-4b may be used jointly or separately as the basis for the sampling plan.

In addition to the regular sample, snubbers which failed the previous functional test shall be retested during the next test period. If a spare snubber has been installed in place of a failed snubber, then both the failed snubber (if it is repaired and installed in another position) and the spare snubber shall be retested. Test results of these snubbers may not be included for tr.e re-sampling.

If any snubber selected for functional testing either fails to lockup r fails to move, i.e., frozen in place, the cause will be evaluated and if caused by manufacturer or design deficiency all snubbers of the same design subject to the same defect shall be functionally tested. This testing requirement shall be independent of the requirements stated above for snubbers not meeting the functional test acceptance criteria.

For the snubber (s) found inoperable, an engineering evaluation shall l

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be performed on the components which are supported by the snubber (s).

The purpose of this engineering evaluation shall ba to determine if the components supported by the snubber (s) were adversely affected by the inoperability of the snubber (s) in order to ensure that the supported component remains capable of meeting the design service.

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l Permanent or other exemptions from functional testing for individual snubbers in these categories may be granted by the Commission only if a justifiable basis for exemption is presented and/or snubber life destructive testing was

, performed to qualify snubber operability for all design conditions at either l the completion of their fabrication or at a subsequent date.

NORTH ANNA - UNIT 2 3/4 7-26b

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PLANT SYSTEMS SURVEILLANCE REQUIKEMENTS (Continued)

d. Hydraulic Snubbers Functional Test Acceptance Criteria The hydraulic snubber functional test shall verify tha+.:

1. Activation (restraining action) is achieved within the specified range of velocity or acceleratirn in both tension and compression.

2. Snubber bleed, or release rate, where required, is within the specified range in compression or tension. For snubbers specifically required to not displace under cortinuous load, the ability of the snubber to withstand load without displacement shall be verified.

e. Mechanical Snubbers Functional Test Acceptance Criteria 1 The mechanical snubber functional test shall verify that:

1. The force that initiates free movement of the snubber rod in either tension or compression is less than the specified maximum drag force. Drag force shall not have increased more than 50% since the last functional test.

2. Activation (restraining action) is achieved within the specified range of velocity or acceleration in both tension and compression.

3. Snubber release rate, where required, is within the speci7ied range in compression or tension. For snubbers specifically required not to displace under continuous load, the ability of the snubber to withstand load without displacement shall be verified.

f. Snubber Service Life Monitoring A record of the service life of each snubber, the date at which the designated service life commences and the installation and mainte-rance records on which the designated service life is based shall be maintained as required by Specification 6.10.2.

Concurrent with the first inservice visual inspection and at least once per 18 months thereafter, the installation and maintenance records for each snubber listed in Tables 3.7-4a and 3.7-4b shall be reviawed to verify that the indicated service life has not been exceeded or will not be exceeded prior to the next scheduled snubber NORTH ANNA - UNIT 2 3/4 7-26c

PLANT SYSTEM 5 SURVEILLANCE REQUIREMENTS (Continued) service life review. If the indicated service life will be exceedeo prior to the nr.xt scheduled snubber service life review, the snubber service life shall be reevaluated or the snubber shall be replaced or reconditioned so as to extend its service life beyond the date of the next scheduled service life review. This reevaluation,

,yeplacement or reconditioning shall be indicated in the records.

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NORTH ANNA - UNIT 2 3/4 7-26d

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ADMINISTRATIVE CONTROLS

c. Each REPORTABLE OCCURRENCE submitted to the Commission.

d. Records of surveillance activities, inspections and calibrations required by these Technical Specifications.

e. Records of changes made to Operating Procedures.

f. .. Records of radioactive shipments.

g. Records of sealed source leak tests and results.

h. Records of annual physical inventory of all sealed source material of record.

6.10.2 The following records shall be retained for the duration of the Facility Operating License:

a. Record: and drawing changes reflecting facility design mndifications made te systems and equipment described in the Final raiety Analysis Report.

b. Records of new and irradiated ft.el inventory, fuel transfers and assembly buroup histories.

c. Records of facility rzciation and contamination surveys.

d. Records of radiation exposure for all individuals entering radiation control areas.

e. Records of ganous and liquid radioactive material release to the environs.

f. Records of transient or operational cycles for those facility components iaentified in Table 5.7-1.

g. Records of reactor tests and experiments.

h. Records of training and qualification for current members of the plant staff.

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

j. Records of Quality Assurance activities required by the QA Manual.

k. Records of the service life of all hydraulic and mechanical snubbers l

listed on Tables 3.7-4a and 3.7-4b including the date at which the I service life commences and associated installation and maintenance records.

l NORTH ANNA - UNIT 2 6-19 Amendment No.

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ATTACHMENT 3 DISCUSSION OF PROPOSED SUPPLEf! ENTAL TECHNICAL SPECIFICATION CHANGE l

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. .o DISCUSSION OF PROPOSED SUPPLEMENTAL Tr:CHNICAL SPECIFICATION CHANGF NORTH ANNA POWER STATION UNITS NO. 1 AND NO. 2 1

A technical review of industry test reports 1.as indicated that Sydraulic shock suppressor (snubber) elastomer seal materials, specifically ethylene-propylene (E-P) compounds, may have a service life in excess of the five year life previously established. While this review is continuing in an effort to further define the expected service life of snubben E-P seal material, service life is dependent on the environment to which a specific snubber is exposed.

In light of this and pending the final results of the seal service life evaluation, a preventive maintenance (PM) prograc is being established to change cut snubber seals or, an interval consistent with seal life, and economic and operational considerations. With the implementation of the PM program, it will no longer be necessary to functionally test and rebuild one-third of the snubbers each 18 months (resulting in a complete change out each four and one-half years).

Rather than implement a seal replacement program by Technical Specifications, the value of "c" in the functional test sample size equation has been revised to the value. 2 from the previously submitted value of 7. With c = 2, the sample size becomes approximately 70 snubbers or 15%. Thus, 15% of the safety related snubbers will be functionally tested each 18 months. This more than satisfies the minimum test sample size of 10%.

The November 20, 1980 letter from the Staff requires the establishment of records of the service lives of all snubbers. The requirement for records of snubber service life was inadvertantly omitted from the July 1,1981 license amendment application and should be included in the administrative controls section. This requirement will ensure that adequate documentation of snubber service life is available for determining snubber service inspection requirements.

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