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Proposed Tech Specs Re Shock Suppressors
	ML20205C789
Person / Time
Site:	Maine Yankee
Issue date:	09/12/1985
From:	; Maine Yankee
To:	;
Shared Package
ML20205C787	List: ML20205C782; ML20205C789;
References
	NUDOCS 8509230213
	Download: ML20205C789 (6)
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MAINE YANKEE ATOMIC POWER COMPANV l

3.20 SHOCK StPPRESSORS (SNUBBERS)

-Applicability:

Applies to those shock suppressors which support safety related systems ))

or components. ))

Objective:

To specify the required condition of protection of shock suppressors ))

required to be operable. ))

Specification:

A. The following conditions apply to snubbers listed in Table 3.20-1: ))]

1. Snubbers shall be operable when the reactor is in Transthermal ))]

Condition (Condition 4) or above and the supported system is ))]

required to be operable'bp technical specifications. ))]

2. RH-HSS-101 and 102 shall be operable whenever there is ))]

irradiated fuel in the reactor and the RHR system is required ))]

to be operable by technical specifications. ))]

Exception: A snubber may be removed from service for a period not ))

to exceed eight hours for the purpose of performing surveillance ))

testing or preventive maintenance. ))

Remedial Action:

1. If any snubber listed in Table 3.20-1 is found to be ))

inoperable, repair and make it operable or replace it with ))

one which is operable within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . ))

2. Perform one of the following within an additional 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months s: ))

Perform an engineering evaluation to demonstrate-operability ))

of the supported system or component with that inoperable ))

snubber: ))

or ))

o Declare the supported system inoperable and follow the ))

Remedial Action statements for that system. ))

B. Snubbers may be added to safety related systems provided that a revision to Table 3.20-1 is included with the next license amendment.

Basis:

Snubbers are designed to limit rapid motion of supported piping ))-

and components under loads which might occur during a severe earthquake ))

or transient while allowing slow thermal nution. An inoperable snubber ))

could lead to loads in excess of design and even structural damage ))

as a result of a seismic or other event producing severe dynamic loads. ))

It is, therefore, required that all snubbers required to protect safety ))

related systems or. components be operable above Condition 4. Snubbers ))]

required to protect the RHR system shall be operable whenever there is ))]

fuel in the reactor and the system is the-required for decayed heat ))]

removal. -

))]

B509230213 850912 .

3.20-1 09/12/85 PDR ADOCK 05000309 '

P PDR

MAINE YANKEE ATOMIC POWER COMPANY Basis (Continued):

The exception to Specification A permits surveillance testing and ))]

preventive maintenance. If the snubber is not returned to service ))

within the eight hour exception, it will be considered inoperable and ))

the Remedial Action will be followed. ))

A period of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is allowed to effect repairs since snubber ))

protection is only required during very low probability events. If the ))

Remedial Action cannot be met, then an engineering evaluation shall ))

be performed within an additional 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to determine the ))

consequences of a seismic event with that inoperable snubber. If the ))

evaluation proves that the supported system would not withstand a ))

seismic event, then the supported system would be considered ))

inoperable. The remedial action for that system would commence, if ))

appropriate, upon completion of the engineering evaluation. ))

3.20-2 09/12/85 5320L-SEN

MAINE YANKEE ATOMIC POWETt COMPANY 4.9 SHOCK StPPRESSOR (SNlBBER) SURVEILLANCE TESTING ))

Applicability:

Applies to the surveillance requirements for' those hydraulic shock suppressors listed on Table 3.20-1.

Objective:

To verify the operability of all safety related hydraulic shock suppressors.

Specification:

A. Visual Inspections: ))

1. All shock suppressors on Table 3.20-1 shall be visually ))

inspected at an interval based on the results of the ))

previous visual inspection and the following table: ))

Nunber of Snubbers Found Inoperable During Visual Next Inspection ))

Inspection Interval Interval (1 25%) )))

0 18 mont E ~

l 12 months 2 6 months 3 or 4 124 days 5, 6 or 7 62 days 8 or more 31 days ))

2. Visual inspections may be divided into groups of accessible ))

or inaccessible snubbers based on their accessability ))

during reactor operation. ))

3. Visual inspection of snubber groups may be performed at ))

different intervals. Inaccessible snubbers may be inspected ))

at the next shutdown of 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months or more. ))

4. Snubbers which fail visual inspections may be considered ))

operable for determining the next inspection interval ))

provided: ))

a. The cause for the rejection is established and remedied ))

for that snubber and all snubbers generically related, and ))

b. Tne operability of the failed snubber (s) is verified by ))

functionally testing it in the as-found condition. ))

Note: 1. These provisions do not apply '.vhen a snubber's ))

fluid port is found uncovered. ))

2. Inoperable snubbers connected to a common reservoir ))

represent one failure for determining next ))

inspection interval unless multiple individual ))]

failures are evident. ))]

4.9-1 09/12/85 5320L-SEN

?:

MAINE YANKEE ATOMIC POWER COMPANY

5. Visual inspections performed at reduced intervals may be ))

limited to inspecting the snubber group for evidence of the ))

known failure mechar. ism, provided a complete inspection is ))

performed on the 18 month interval. ))

6. Visual inspection intervals may not be lengthened by more ))

than one step at a time. ))

7. The provisions of Specification 4.0 are not applicable. ))

B. Ftnctional Tests ))

1. Once each operating cycle, a representative sample group of ))

snubbers from Table 3.20-1 will be functionally tested. ))

2. The functional test sample group will be comprised of the ))

snubbers which failed the functional test during the lest ))

operating cycle plus an additional ten percent selected ))

from Table 3.20-1. ))

Note: Snubbers selected from Table 3.20-1 for inclusion in ))

the sample group should be selected so that all snubbers ))]

are tested before retesting. ))

3. If any snubber fails the function &l test: ))

a. All snubbers generically related to the failed snubber ))

(same design subject to the same deficiency) shall be ))

functionally tested for that failure, and ))

b. An additional ten percent shall be added to the sample ))

group for each snubber failure. ))

Note: Inoperable snubbers connected to a common reservoir ))

represent one failure for determining additions to ))

the sample group unless multiple individual failures ))]

are evident. ))]

4. Functional testing shall continue until there are no failures ))

or until all snubbers on Table 3.20-1 have been tested. ))

))]

C. Snubber Service Life Monitcring ))

1. Each refueling outage it shall be verified that the snubbers ))

on Table 3.20-1 will not exceed their expected service life ))

before the next refueling outege. ))

2. If a snubber's expected service life expires before the ))

next refueling outage, the service life may be extended ))

by reevaluating, reconditioning or replacing that snubber ))

and recording that maintenance in appropriate records. ))

4.9-2 09/12/85 5320L-SEN

MAINE YANKEE ATOMIC POWER COMPANY Basis:

The visual inspection shall include, but not necessarily be limited ))

to, inspection of the hydraulic-fluid reservoir, fluid connections, ))

and linkage connections to piping and anchors. The inspection shall ))

verify operability by determining that there are no visible ))

indications of damage or impaired operability, and no visible ))

indications of insecure foundation attachments or supporting ))

structures. To simplify tracking of inspection intervals, the ))

ir.spections should be performed in groups of snubbers rather than ))

individual snubbers. ))

The inspection frequency is based upon maintainir.g a constant level of snubber protection. Thus, the required inspection interval varies inversely with the observed snubber failures within each group. ]

The number of inoperable snubbers found during the required inspection determines the time interval for that group's next required inspection. ]

One failed snubber connected to a common reservoir may permit the ))

hydraulic fluid to drain from all the snubbers common to that reservoir, ))

thus rendering them inoperable. In this situation, only the snubber ))

which caused the failures is considered inoperable. ))

Inspections performed before that interval has elapsed may not 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%) may not be used to lengthen the required inspection interval. Any iaspection whose results require a shorter inspection interval will override the previous schedule.

To further increase the assurance of snubber reliability, functional ]

tests should be performed once each refueling cycle independent of ))

visual inspections. Functional tests shall verify operability by ))

determining that (1) activation (restraining action) is achieved ))

within the specified range of velocity or acceleration in both tension ))

and.conpression and (2) snubber bleed, or release rate, where ))

required, is within the specified range in compression or tension ))

and, (3) the snubber is able to withstand load without displacement ))

for snubbers specifically required not to displace under continuous ))

load. ))

))]

4.9-3 09/12/85 5320L-SEN

M AINE YANKEE ATOMIC POWER COMPANY

1. 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 reviews performed for changes made to procedures or equipment or reviews of tests and experiments pursuant to 10 CFR 50.59.

1. Records of meetings of the POR and the NSAR Committees.

m. Records of Environmental Qualification which are covered under the provisions of paragraph 5.13.

n. Records of the service lives of all snubbers listed on Table 3.20-1 ))

including the date at which the service life commences and associated ))

installation and maintenance records. (See Specification 4.9.c) ))

0 4

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-5.10-2.. 09/12/85 5320L-SEN

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ML20205C789

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