ML20086D097

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Proposed Tech Specs Re Snubber Visual Insp Schedule
ML20086D097
Person / Time
Site: FitzPatrick Constellation icon.png
Issue date: 11/15/1991
From:
POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:
Shared Package
ML20086D079 List:
References
NUDOCS 9111250247
Download: ML20086D097 (16)


Text

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ATTACHMENT I to JPN 91-063 PROPOSED TECHNICAL SPECIFICATION CHANGES SNUBBER VISUAL INSPECTION SCHEDULE (JPTS-91-011)

Nev' York Power Authority JAMES A. FITZ W M. NUCLEAR POWER PLANT "w" . No. 50 333 DPR-59 9111250247 911113 FDR ADOCK 05000333 P PDR

JAFNPP LIST OF TABLES (Cont'd)

Tablo Titto Pago 4.5: 0 Minimum Test and Calibration Frequency for Accident Monitortr'g 8Ga IT:urnonteflon 4.6-1 Snubber Visua!!nspection Intervai 161 l 4.62 Minimum Test and Calibration Frequency for Drywell Continuous 162a Atmosphoro Hadioac'lvity Monitoring System 3.7 1 Primary Contalnment isolation Valvos 198 4.7 1 Minirnum re st and f'.alibration Frequency for Containment Monitoring 210 Systems 4.7 2 Exception ;o Typo C Tests 211 3.12 1 Water Spray /Sprinklor Protected Arcas 244]

3.12 2 Carbon Dioxido Prot 3cted Arcas 244k 3.12 3 Manual Firo Hoso Stations 2441 4.12 1 Water Spray /Sprinkfor System Tests 244q 4.12 2 Carbon Dioxido System Tosts 214r 4.12 3 Manual Firo Hoso Station Tests 244s J.2 1 Minimum Shift Manning Roquirements 260c 6.10 1 Component Cyclic or Translent Umits 261 Amendment No. , , 1,1 ,1 ,1 ,

vi

JAFNPP ,

.;l R6 (cont *d) 4.6 (cont'd) .

. u .e Suppressors (Snubbers) 1. Shock Suppressors (Snubbers)

Applicacility Applicability -

Applies to the coerational status of the shock suppressors Applies to the periodic testing requirement for the shock suppressors (snubbers).

(snubbers).

Objective Objecti.e To assure the capability of h snubbers to: To assure the capaLi!ity of the snubbers to perform their intended functions.

Prevent unrestrained pipe motion urdu dunamic loads as might occur during an earthquake or severe transient, and Allow normal thermal motion during startup and shutdon Specification Specification Each snubber shail be demonstrated ope able bu performance of the foMwing augmented inservice inc . ' ogtam.

1. During all modes of operation except Cold Shutdown and 1. AII snubbers shall be categore bv design and Refueling, all snubbers which are required to protect the manufacturer type. The snubbs ., be further primary coolant system or any other safety related system categonzod into two subgroups: those access;bie and -

or component shall be operable. During Cold Shutdown or those inaccrJble during reactor operation. The visual l Refueling mode of operation, only those snubbers sha!! be inspection interval for each category of snubbers shaft be operabic which are on systems that are required to be determined based upon the criteria provided in Table 4.6-1. ;

operable in these modes.

l Amendment No. , ,

145b c-. - .,

1 I' JAFNPP

  • i - .

i; 3.6 (cont'd) 4.6 (cont'd) .

l

' 2. 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 /> 2. Visual inspection shall venfy (1) that there are no visible during normal operation, or within 7 days during Cold indications of damage or impaired OPERAB!UTY, (2) i Shutdown or Refueling mode of operation for systems attachments to the foundation or supporting stnzture are which are required to be operable in these modes, secure, and (3) in those locations where snubber complete one of the following: movements can be manually induced without disconnecting the snubber, that the snubber has frcsi&O

a. replace or restore the inoperable su~t>er(s) to of movement and is not frozen up. Snubbers vtiich j

oprable status or, appear inoperabio as a result of vtsual inspections may be determined OPERABE for the purpose of establishing the

b. declare the supported system inoperab!c and foflow i next visual inspection interva!, providing that (1) the cause the appropriato limiting condition for operation s emen at system or, is M MM WMM h M articular snubber and for other snubbers that may be
c. perform an engineering evaluation to show the generica!!y susceptible; and (2) the affected snubber is inoperable snubber is unnecessary to assure functionally sted in the as found condition and operability of the system or to meet the design determined OPERABE per Specificatiore 4.617 or 4.6.I.8, criteria of the system, and remove the snubber from as applicable. Hydraul;c snuboers which have lost the system. sufficient fluid to poterfdaily cause uncovering of the fluid

, reservoir-to-snubber valve assembly port or bottoming of the fluid reservoir piston with the snubber in the fully exteraded position sha!I be functionalty tested to determine operability.

3. With one or more snubbers founo inoperable, w: thin 72 3. Once each operating cycle,10% of each type of snubbers hours perform a visual inspection of the supported shaft be functiona!!y tested for operability, either in place or component (s) associated with the inoperab!e snubber (s) in a bench t2st. For each unit and subsequent unit that and document the results. For a!1 modes of operation does not meet the requirements of 4.6.I.7 or 4.6.1.8, an
except Cold Shutdown and Refueling, within 14 days additional 10% of that type of snubber shafi be functionar complete an engineering evaluation as per Specification tested until no more failures are found, or a!! units hr..

4.6.l.6 to ensure that the inoperable snubber (s) has not been testM.

adversely affected the suppor'ed cwnporent(s). For Cold Shutdown or Refueling mor'e, this evaluation shall be completed within 30 days.

Amendment No. , 1 ,

145c

JAFNPP

.= l l

3.6- (cont'd) 4.6 (cont'd)  !

t

~

l

4. The representative sample selected for functiona!!y testing '

shall include the various configurations, operating envi(Onnients ard the range of size and capacity of

, snubbers. At least 25% of the snubbers in the  ;

j representative sample sha!! include sh. from the ,

fo!!owing three categories:  ;

The first snubber away from reactor vessel nozzle.

a.  ;
b. Snubbers within 5 feet of heavy equipment (valve, pump, turbine, motor, etc.).
c. Snubbers within 10 feet of the discharge from a
safety relief valve.  !

~i 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 insta!!ed in piace of a failed snubber, then both the failed snubber (if it is repaired and installed in another position) and the spare ,

j snubber shall be retested. Test results of these snubbers may not be included for the re-sampling. ,

I  :

! i j -

i t

4 ,

, f 1 L 4

e g i

9 +i e.- -- r>-.-- ~ w ==r

JAFNPP ,

3.6 (cont'd) - ~

4.6 (cont'd) ~

l

5. If any snubber selected for functional testing either fails to lockup or fails to rnove, i.e. is frozen in place, the cause will be evaluated and if due to rnanufacturer or design deficiency, snubbers of the same design subject to the same defect shall be functionally tested. This testing requirement shall be independent of the requiremerfs stated above for snubbers not meeting the functional test acceptarm criteria.
6. For the snabber(s) found inoperable, an engineering evaluation shall be performed on the componerfs wNch 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 suppcrted components remain capable of meeting the designed service requirements.

l l

f i

Amendment No.

145e

JAFNPP . ~.

~

3.6 and 4.6 BASES (cont'd) .

H' (DELETED) supported component (s) associated with the inoperable snubber (s) and the results ; 6 be documented. For a!! modes of operation except Cold ShCown and Refueling, within 14 L Shock Suppressors days an engineering evaluation shaft be performed to ensure that the inoperable snubber (s) has not adversely affected the Snubbers are designed to prevent unrestrained pipe motion supported component (s). For Cold Shutdown or refuering under dynamic loads as might occur during an earthquake or mode, this evaluation shall be completed within 30 days. A severe transient, while allowing normal themial motion during period of 7 days has been selected for repair or replacement of startup and shutdown. The consequence of an inoperable the inoperable snubber during cold shutdown or refueling snubber is an increase in the probability of structural damage mode of operation becuase in these modes the relative to piping as a result of a seismic or other event initiating probability of structural damage to the piping systems would dynamic loads. It is therefore required that all snubbers be lower due to lower values of total stresses on the piping required to protect the primary coolant system or any other systems. In case a shutdown is required, the a!!awance of 36 safety system or component be operable during reactor hours to reach a cold shutdown condition will permit an orderly operation. Snubbers excluded from this inspection program shutdown consistent with standard operating procedures.

are those installed on non-safety related system and then on!y if their failure or failure of the system on which they are The visual inspection frequency is based upon maintaining a installed would have no adverse effect on any safety-related constant level of snubber protection to systems. Therefore, the system. Because the snubber protection is required only required inspection intental varies inversely with the observed during 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 /> (fcr normal snubber fa!!ures and is determined by the number of inoperable operation) or 7 days (for cold shutdown or refueling mode of snubbers found during an inspection. Inspectiors performed operation) is allowed for repairs or replacement of the snubber before that interval has elapsed may be used as a new prior to taking any other action. Following the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (or 7 reference point to determine the next inspection. The day) period, the supported system must be declared inspections are performed for each category of snubbers. The inoperable and the Umsting Condition of Operation statement snubbers are categorized by types of the same design and for the supported system followed. As an a!temative to manufacturer, irrespective of capacity. These categories may snubber repair or replacement an engineering evaluation may be further sebcategorized cy accessibility (i.e., accessible or be performed: to show that the inoperable snubber is inaccessible during reactor operation). The next visual unnecessary to assure operability of the system or to meet the inspection for each category may be twice, the same, or design criteria of the system; and, to remove the snubber from reduced by as much as two-thirds of the previous inspection the system. With one or more snubbers found inoperable, interval. This interval depends on the number of unacceptable within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> a visual inspection shall be performed on the snubbers found in proportion to the total number of snubbers g Amendment No. ,

JAFNPP . .

3.6 and 4.6 BASES (cont'd) in each category from the previous inspection. The intervals order to determine if any safety-related component or system may be increased up to 48 months if few unacceptable snubbers has been adversely affected by the inoperability of the snubber.

are found in the previous inspection. The visual inspection The engineering evaluation shall determine y,tiether or not the interval will not exceed 48 months. However, as for all snubber mode of failure has imparted a significar't effect or surveillance activities, unless otherwise noted, allowable degradation on the supported ccTiponent or systera.

tolerances of 25% are applicable for snubbers. Table 4.6-1 '

establishes three limits for determining the next visual inspection To provide ' assurance of snubber functional reliability, a interval corresponding to the population of each category of representative sample of the insta!!ed snubbers will be snubbers. For a category that differs from the representative functionally tested during each operating cycle. Selection of a sizes provided, the values for the next irupection interval may be representative sample of 10% of each type of safety related found by interpolation from the limits provided in Columns A, B, snubbers provides a confidence level within acceptable limits and C. Where the limit for unacceptable snubbers in Columns A, that these supports will be in an operable condition. Observed B, or C is determined by interpolation and includes a fractional failures of these sample snubbers sha!! require functiona: testing value, the limit may be reduced to the next lower integer. The of additionalunits.

first inspection interval determined using Table 4.6-1 shall be based upon the previous inspection interval as established by Hydraulic snubbers and mechanical snubbers may each be the requirements in ef*ect before amendment ( ). Any treated as a different entity for the above survoittance programs.

inspection whose results require a shorter inspection interval will override the previous schedule. When the cause of the rejection - The service life of a snubber is evaluated using manufacturer of a snubber is cicarty established and remedied for that snubber input and information and also through consideration of the and for any other stubbers that may be generically susceptible, installation and maintenance records (nevdy insta!!ed snubber, and verified by inservice functional testing, that snubber may be seal replaced, spring replaced, in high radiation area, in high exempted from being counted as inoperable. Generica!!y temperature area, etc ). The requirement to monitor the i susceptible snubbers are those which are of a specific make or snubber service life is included to ensure that the snubbers j model that have the same design features directly related to periodically undergo a perfow+xe evaluation in view of their i

rejection of the snubber by visual inspection, and are similarly age and operating conditions. These records will provide located or exposed to the same environmental conditions such statis'ical bases for future consideraJon of snubber service life.

as temperature, radiation, and vibration. When a snubber is The requirements for the maintenance of records and the found inoperable, an engineering evaluation is performed, in snubber service life review are not intended to affect plant eddition to the determination of the snubber mode of failtre, in operation.

i .

Amendment No. ,

3 156a

.~

JAFNPP .

s i

l PAGES 157 THROUGH AND INCLUDING 160 HAVE BEEN INTENTIONALLY LECT BLANK Amendment No. ,

4 ,e  ;

JAFNPP e

Tabic 4.G 1 l Snubber VisualInspection Intorval l l

l Number of Unacceptablo Snubbois Column A3 Column 8 4 Column C"' l Population ,2 1 Extended Repeat Roduco

/ Category Interval Interval Interval l

1 0 0 1 80 0 0 2 100 0 1 4 150 0 3 8 200 2 5 13 300 5 12 25 Notos: 1. Tho next visual inspection interval for the population of a snubbor category shall bo dotormined based upon the previous inspoction interval and the number of unacceptab!o snubbers found during that interval. Snubbors may t's categorized, based upon their accessibility during power operation, as accessiblo or inaccessible. Thoso categorios may be examined separately or jointly. ~,'his decision shall bo mado and documented beforo any inspection and usod as tho basis upon which to dotormino the next inspection interval for that category.

2. Interpolation betwoon population or catogr.ry sizes and the number of unacceptablo snubbors is permissible. Tno next lower integer for tho value of the limit for Columns A, B, C shall bo used if that integer includos a fractional valuo of unacceptable snubbers as dotormined by interpolation.
3. If the number of unacceptablo snubbers is oqualin or loss than tho number in Column A, the rioxt inspection interval may be twico the previous interval but not greator than 48 months.
4. If the number of unacceptablo snubbers is equal to or loss than the number in Column B but greator than the number in Column A, the next inspection intorval shall be the samo as the previous interval.

Amendment No. ,

161 l

JAFNPP i

i Tablo 4.61 (cont'd}

Snubbor VisualInspection Intorval

5. If tho number of unacceptablo snubbers is equal to or greator than the number in Column C, the next inspection interval shall bo two-thirds of the previous interval. However,if the number of unacceptablo snubbors is loss than tho number in Column C but greator than the number in Column D, tho next interval shall bo reduced by a factor that is ono-third of the ratio of tho difference betwoon the number of unacceptable snubbers found during the previous intarval and the number in Column B to the difforenco in the numbors in Columns B and C.

Amendment No. ,

162

Attachment 11 to JPN 910R3 SAFETY EVALUATION FOR PROPOSED TECHNICAL SPECIFICATION CHANGES SNUBBER VISUAL INSPECTION SCHEDULE (JPTS-91011)

I, DESCRIPTION OF THE PROPOSED CHANGES This application for an amendment to tho James A. FitzPatrick Technical Specifications proposes a revisod scheduto for visual inspection of shock suppressors (snubbors). The proposed changos ato as follows:

Pago vi, Ust of Tables Itom 4.6-1 Roplaco the titlo " Comparison of the James A. FitzPatrick Nuclear Power Plant inservico inspoction Program to ASME Inservice Inspection Codo Roquiroments" and pago *157" with the following titto *Snubbor Visual inspection Interval" and pago "161."

Pago 145b, Specification 4.6.1.1 D01010 the column titlos, " LIMITING ?ONDITION FOR OPERATION" and " SURVEILLANCE REQUIREMENT."

Replaco

  • Snubbors shall bo visually inspocad in accordance with tho following schedulo:

I No. Inoporablo Snubbers Subsequent Vist'al

(

1 por Inspection Period Inspection Period *#

0 18 months 25 %

1 12 months 125%

l 2 6 months 125%

3, 4 124 days 25%

5,6,7 62 days 25%

8 or moro 31 days 2 25%

l

  • The inspection interval may not be extended more than ono stop at the timo."

with "All snubbers shall be categorized by design and manufecturer type. The snubbers may bo further categorized into two subgroups: thoso accessible and thoso inaccessible during reactor operation. The visual inspection interval for cach category of snubbors shall bo dotormined based upon the critoria provided in Table 4.01."

Pago 145c, Specifications 3.6.l.2 and 4.6.l.1 Move the boginning of Specification 3.6.l.2 from page 145b to the top of the first column.

l l

. Attachmont il to JPN 91-0G3 SAFETY EVALUATION Pago 2 of 5 From Specification 4.6.l.1, doloto the footnote:

'# Tho snubbers may be categorized into two groups: Thoso accessible and thoso inaccessiblo during rcactor oporation. Each group may be inspected indopondently in accordanco with the above schoduto." c Pago 145d, Specifications 4.6.l.2 and 4.G.I.3 Movo the romainder of Specification 4.G.I.2 and all of Specification 4.G.I.3 to tho end of tho second column of pego 145c.

Pago 1450, Specification 4.61.4 l

Movo the remainder of Specification 4.6.1.4 to the end of the second column of page 145d.

l Page 156a, Bases 3.6 and 4.6 i Replace the sentonce "However, tho results of such early inspection performod before the original required timo interval has elapsed (nominal timo loss 25%) may not be used to longthen the requirod inspection intorval." ,

with the following paragraph "The inspections are performed for cach category of snubbers. The snubbers are categorized by typos of the same design and manufacturor,irrespectivo of capacity.

These categories may be further subcategorized by accessibility (1.0., accessibio or inaccessible during reactor operation). The next visual inspection for each category may be twice, the same, or reduced by as much as two thirds of the previous

' inspection interval. This interval doponds on the number of unacceptablo snubbers found in proportion to the total number of snubbers in cach category from the previous inspection. The intervals may bo increased up to 48 months if few unacceptable snubbors are found in tho previous inspection. The visual inspection interval wVI not exceed 48 months. However, as for all surveillanco activitics, untoss othorwise noted, allowable tolerances of 25% are applicable for snubbers. Table 4.6-1 ostablishes throo limits for determining the next visual inspection interval corresponding to the population of each category of snubbers. For a category that l

differs from the representative sizes provided, the values for the next inspection interval may be found by interpolation from the limits provided in Columns A, B, and C. Where the limit for unacceptable snubbers in Columns A, B, or C is determined by interpolation and includes a fractional value, the limit may be reduced to the next lower integor. The first inspection interval determined using Table 4.61 shall be based upon the previous inspection Interval as established by the requirements in offect boforo amendment ( ) ."

I t .- - . . .

, . Attachment 11 to JPN 91-0G3 SAFETY EVALUATION Pago 3 of 5 Page 156a. Bases 3.6 and 4.6 i Movo tho starting point of the paragraph "The visual inspection frequoney ...", to the end of the second column of pago 156.

Pago 157162, Intentionally Blank Roolace the phraso "through and including 162* with the phraso "through and including 160".

Renumber the pago as *157160."

Pages 161 and 162, Table 4.6-1 Insort a now Tablo 4.6-1, " Snubber Visual Inspection Interval."

11. PURPOSE OF THE PROPOSED CH ANGES The proposed changos to Section 4 6.1 of the James A. FitzPatrick Technical Specifications reviso the schedulo for visual inspection of snubbors consistent with tho guidanco provided in Gonoric Lottor 90-09 (Referenco 3). The revised visual inspection scheduto is based on the number of unacceptablo snubbers found during the previous inspection, tho sizo of tho various snubber populations or categories and the length of the previous inspection interval.

Ill. SAFETY IMPLICATIONS OF THE PROPOSED CHANGES Snubbers are designed to provent unrestrained pipo motion under dynamic loads as might occur during an carthquake or sovero transient, whilo allowing normal thermal motion during startup and shutdown. These snubbers, mechanical and hydraulic, provido protection to the primary coolant system and other safety related components.

To ensure that the snubbers properly perform their intended function, they are subjected to periodic functional and virual inspections. Functional tests verify that snubbors can operato within l specific paramotor limits. Visualinspections are the observation of tho condition of installed I snubbers to identify those that are damaged, degraded, or inoperable. Visual examinations l complomont the functional testing program and provido additional assuranco of snubber

- operability.

The existing surveillance interval is based on an eightoon month operating cyclo and the number

, of inoperablo snubbors found during the previous inspection, regardless of the number of snubbers in that category. These critoria can result in excessivo radiologica! personnel exposures and can ontail a significant amount of site resourco: which the a!!ornato scheduto will climinato.

This reduction is consistent with the Commission's policy statomont on Technical Specification improvements.

. Attachmont il to JPN 91-0G3 SAFETY EVALUATION Pago 4 of 5 Although the now visual inspection schodulo will chango the methodology used in dotermining tho duration betwcon visual inspections for the snubbors, tho snubbers are still Inspected based on the number of unacceptablo snubbers. Thoro will bo no changes to the interval for functional inspections which is based on the operating cyclo. The proposed inspoction interval was developed based on an operating cyclo of up to 24 rnonths while maintaining the samo confidenco lovol in snubbor operability.

Tho grouping of snubbers into soveral populations allows cach group to bo inspected based on tho failuro ratos for that particular grouping. Groups which fail visual inspection can thereforo bo inspected more froquently without requiring all snubbers to bo ir.spected at the same rato. By concentrating plant resources on thoso snubbors which requito increased visual inspection, thoso changes improvo plant maintenance whilo decreasing personnel radiation exposurcs.

IV. EVALUATION OF SIGNIFICANT H A7.ARDS CONSIDERATION Oporation of the FitzPatrick plant in accordanco with the proposed Amendment would not involvo a significant hazards consideration as defined in 10 CFR 50.92, sinco it would not:

1. Involvo a significant increaso in the probability or consequences of an accident previously evaluated.

The proposed changes involvo no hardwaro changes, no changos to the operation of the snubbors, and do not chango the ability of the snubbers to perform their intended functions. An increato in visual inspection frequency will not affect the confidence lovel in operability developed from functional testing.

2. croato the possibility of a new or different kind of accident from thosa previously ovaluated.

Tho proposed changes involvo no hardwaro changos, no changes to tho operation of the snubbers, and do not chango the ability of the snubbers to perform their intended functions. The now visua inspection interval does not chango the level of confidenco in snubbor operability developed from functional testing and thoroforo no unroviewed failure mechanism can result.

3. Involvo a significant reduction in the margin of safety.

The propos Ed changes involvo no hardware changos, no changos to the operation of the snubbers, and do not chango the ability of the snubbers to perform their intended functions. The proposed amendment incorporates the alternato Technical Specification requirements for visual inspection of snubbers identified in Generic Lottor 9409. The attornato visualinspection criteria considor the size of the category of snubbers when ovaluating inspection intervals duo to failure ratos. They do not

. . Attachmont !! to JPN 91-063 SAFETY EVALUATION Pago 5 of 5 reduco the confidence lovel in snubber oporability. The functional testing

- requiromonts romain unchanged and do not reduco operability confidenco lovels.

V. IMPLEMENTATION OF THE PROPOSED CHANGES Implomontation of the proposed changos will not adversely affect the ALARA or Firo Protection Program at the FitzPatrick plant, nor will the changes impact the environment. The results of thoso changes are expected to reduce the doso to plant personnel since the number of inspections performed b closo proximity to radiological sourcos will be reducod. The proposed changos will not chango the inspection methodology currently in place and thoroforo can have no impact on the Firo Protection program or the environment.

VI. CON .USION l Thoso changos, as proposod, do not constituto an unroviewed safety question as defined in 10 CFR 50.59. That is, they:

a. will not increaso the probability of occurronce or the consequencos of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report;
b. will not increase the possibility for an accident or malfunction of a type different from any evaluated previously in the safety analysis report;
c. will not reduco the margin of safety as defined in the basis for any technical specification; and
d. Involves no significant hazards consideration, as definod in 10 CFR 50.92.

l Vll. REFERENCES

1. James A. FitzPatrick Nuclear Power Plant Updated Final Safety Analysis Report,-

Section 12.5.4.

2. James A. FitzPatrick Nuclear Power Plant Safety Evaluation Report (SER), dated L

November 20,1972, and Supplomonts.

L 3. NRC Generic Lotter 90-09, "Alternativo Requirements for Snubber Visual Inspection Intervals and Cortoctivo Actions", dated December 11,1990.

4. NYPA lotter, J. C. Brons to tho NRC, dated December 28,1990, (JPN.90-078, IPN 060', "Now Projects "

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