ML20054D143

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Proposed Tech Spec Changes Re Exemption from Requirement to Perform Functional Testing for Snubbers Greater than 50,000 Kips Around Steam Generators & Reactor Coolant Pumps During Upcoming Refueling & Maint Outages
ML20054D143
Person / Time
Site: North Anna  Dominion icon.png
Issue date: 04/16/1982
From:
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20054D129 List:
References
NUDOCS 8204220378
Download: ML20054D143 (8)
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ATTACHMENT I r

8204220378 820416 I PDR ADOCK 05000330 PDR P

PLANT SYSTEMS SURVEILLANCE 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 snubber 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 functi'onal 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 the re-sampling.

If any snubber selected for functional testing either fails to lockup or 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. l

  1. The requirement to functionally test large snubbers greater than 50,000 kips around the steam generators and reactor coolant pumps, is exempt from functional testing for the representative sample of snubbers selected for testing during the Cycle 3 refueling and maintenance outage.
  • 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 the completion of their fabrication or at a subsequent date.

NORTH ANNA - UNIT 1 3/4 7-29a -

PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) {

r For the snubber (s) found inoperable, an engineering evaluation shall be performed on the components which cre supported by the snubber (s). The purpose of this enginerring evaluation shall be to determine if the components supported by the snubber (s) were adversely affected by the inoperability of the snubber (s) in i order to ensure that the supported component remains capable of meeting the ,

desiga service. '

d. Hydraulic Snubberc Functional Test Acceptance Criteria The hydraulic snubber functional test shall verify that:
1. Activation (restraining action) is achieved within the specified range of velocity or acceleration 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 continuous load, the ability of the snubber to withstand load without displacement shall be verified.
e. Mechanical Snubbers functional Test Acceptance Criteria The mechanical snubber functional test shall verify that:
1. The force that initiates free moven.ent of the snubber rod in either tension or compression is less than the specified maximum drag force.

Drag force shall not have increased mere 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 specified 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 maintenance records on which the designated service life is based shall be maintained as required by Specification 6.10.2.

NORTH ANNA - L' NIT 1 3/4 7-29b

PLANT SYSTEMS SURVEILLANCE REAUIREMENTS (Continued)

At least once per 18 months, the installation and maintenance records for each snubber listed in Tables 3.7-4a and 3.7-4b shall be reviewed to verify that the indicated service life has not been exceeded or will not be exceeded prior to the next scheduled snubber service life review. If the indicated service life will be exceeded prior to the next 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, replacement or reconditioning shall be indicated in the records.

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NORTH ANNA - UNIT 1 3/4 7-29c e

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ATTACHMENT 2 i

PLANT SYSTEMS SURVEILLANCE 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 snubber 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 Eadiation 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 cf a failed snubber, then both the failed snubber (if it is repaired and installed in another i position) and the spare snubber shall be retested. Test results of these snubbers may not be included for the re-sampling.

If any snubber selected for functional testing either fails to lockup or fails to move, i.e., frozen in place, the cause will be i 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.

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  1. The requirement to functionally test large snubbers greater than 50,000 l kips, around the steam generators and reactor coolant pumps, is exempt from functional testing for the representative sample of snubbers selected for testing during the Cycle 1 refueling and maintenance outage.
  • Permanent or other exemptions from functional testing for individual snntbers in these categories may be granted by the Commission only if a just .fiable basis for exemption is presented and/or snubber life destructive testing was performed to qualify snubber operability for all design conditions at either the completion of their fabrication or at a subsequent date.

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

PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) _,

For the snubber (s) found inoperable, an engineering evaluation shall be performed on the components which are supported by the snubber (s). The purpose of this engineering evaluation shall be 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.

d. Hydraulic Snubbers Functional Test Acceptance Criteria The hydraulic snubber functional test shall verify that:
1. Activation (restraining action) is achieved within the specified range of velocity or acceleration 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 continuous load, the ability of the snubber to withstand load without displacement shall be verified.
e. Mechanical Snubbers Functional Test Acceptance Criteria 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 compress on.
3. Snubber release rate, where required, is within the specified 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-nance records on which the designated service life is based shall be maintained as required by Specification 6.10.2.

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

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l PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) l 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 reviewed to verify that the indicated service life has not been exceeded or will not be exceeded prior to the next scheduled snubber service life review. If the indicated service life will be exceeded prior to the next 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, replacement or reconditioning shall be indicated in the records.

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ATTACHMENT 3 i

DISCUSSION OF PROPOSED TECHNICAL SPECIFICATION CHANGES

Background

Presently, Technical Specification 3/4.7.10 states that "at least once per 18 months during shutdown a representative sample of that number of snubbers whichfollowstheexpression35(1%),wherec=2istheallowablenumberof snubbers not meeting the acceptance criteria selected by the operator shall be functionally tested either in-place or in a bench test". The Technical Specifications also state "at least 25% of the snubbers in the representative sample shall include snubbers within 5 feet of heavy equipment". The 10 inch and 14 inch snubbers (greater than 50,000 kips) around the steam generators and reactor coolant pumps are included in this representative sample.

Justification Functionally testing large snubbers greater than 50,000 kips, around the steam generators and reactor coolant pumps would create a personnel radiation exposure problem. The radiation exposure rate at the steam generator snubber supports is approximately 25 mR/hr. and at the reactor coolant pump snubber supports is approximately 75 to 400 mR/hr. These high exposure rates are not consistent with the ALARA program.

In addition, the large snubbers greater than 50,000 kips do not have valve adjustments to control the bleed rates like smaller snubbers. These larger snubbers have orifice plates and there is no drift during power operation.

The seals on the larger snubbers are qualified for 10 years and the seals are visually inspected each refueling outage. An exemption from functionally testing snubbers greater than 50,000 kips would prevent radiation exposure to personnel and would not degrade any part of the operating plant.

Safety Evaluation The probability of occurrence or the consequences of a malfunction of equipment important to safety and previously evaluated in the FSAR is not increased because of the exemption of functionally testing snubbers greater than 50,000 kips. This is because the snubbers greater than 50,000 kips do not have valve adjustments to control bleed rates and the seals are qualified for 10 years.

The possibility of a different type of accident or malfuntion than was previously evaluated in the FSAR has not been created because no physical modifications will be made and all snubbers greater than 50,000 kips will remain in service.

The margin of safety as described in the BASIS section of any part of the Technical Specifications is not reduced because snubbers greater ths.n 50,000 kips do not have valve adjustments to control bleed rates and the seals are qualified for 10 years. There is no drif t on these snubbers during power operation, therefore structural integrity of the RCS and other safety related systems is maintained.

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