ML20032D838

Requests Response to Encl 810210 Generic Ltr 81-14, Seismic Qualification of Auxiliary Feedwater Sys. Requested Info Should Be Submitted No Later than 811231

ML20032D838
Person / Time
Site:	Sequoyah
Issue date:	10/29/1981
From:	Adensam E Office of Nuclear Reactor Regulation
To:	Parris H TENNESSEE VALLEY AUTHORITY
References
GL-81-14, NUDOCS 8111180082
Download: ML20032D838 (3)

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nanager of Power Tennessee Valley Authority Lt1 NOV0 31985 h 500 A Chestnut Street Tower 11 u.s.,suae%=

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Dear Mr. Parris:

o, Suoject: TVA's Response to Generic Letter 81-14

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In a recent telecen with your staff, we were notified that TVA has not fonaally received Generic Letter 81-14, " Seismic Qualificatiott of Auxiliary feed, tater Systeas" cated February 10, 1981.

Our docket records indicate this letter was sent to you in Harch 1981.

In addition, copies +ere forwarded to your staff infor;r. ally in late June and August.

Enclosed is a copy of the letter. We request you sub ;f t the requested infonaation no later than Deceraber 31, l!r81.

Sincerely, Elinor G. Adensam, Unief Licensing Branch No. 4 Division of Licensing

Enclosure:

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MDuncan SHanauer RTedesco dr. H. 6. Parris RVollmer lianager of Power TMurley Tennessee Valle/ Authority RMattson 300 A r,nestnut Street Tower II RHartfield, MPA chattanooga, Tennessee 37401 0 ELD OIE (3)

Uear dr. Parris-subject: TVA's Aesponse to beneric Letter 81-14 In a recent telcon en th your staff, we nave been notified that TVA no:, not forually receivec Generic Letter 61-14, " Seismic qualification of noxiliary Feednater Syster.:s" dated Feuruary 10, 1981.

Uar auctet records inoicate tnis letter was se:O 1.0 you in liarch 1931.

In accition, copics liave Deen for..arded to your stcff inforg. ally in late June and Aujust.

ousmis a copy of tua letter. We request you subait tne rquestec information no later tnen Deceaber 31, 1981.

y Sincerely,

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f.linor 6. Adensan, Chiet Licensing branch No. 4 Division of Licensing

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SEQUOYAH Mr. H. G. Parris Manager of Power Tennessee Valley Authority 500A Chestnut Street, Tower II

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Chattanooga, Tennessee 37401 cc:. Herbert S. Sanger, Jr., Esq.

General Counsel Tennessee Valley Authority 400 Comerce Avenue E 118 33 Knoxville, Tennessee 37902 Mr. H. N. Culver Tennessee Valley Authority 400 Comerce Avenue, 249A HBB Knoxville, Tennessee 37902 Mr. Bob Faas Westinghouse Electric Corp.

P.O. Box 355 Pittsburgh, Pennsylvania 15230 i

Mr. Mark Burzynski Tennessee Valley Authority 400 Chestnut Street Tower II Chattanooga, Tennessee 37401 Mr. J. F. Cox Tennessee Valley Authority i

400 Comerce Avenue, W10C131C I

' Knoxville Tennessee 37902 Resident Inspector /Sequoyah NPS c/o U.S. Nuclear Regulatory Comission 2600 Igou Ferry Road Sodcty Daisy, Tennessee 37379 a

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FE3101981

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TO ALL OPERATING PRESSLRIZED WATER REACTOR LICENSEES SEISMIC QUALIFICATION 0F AUK!LIART FEETAIATER SYSTE

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SUBJECT:

(Generic Letter No. 81-14) 21, 1990, identifled concerns regarding Our letter to you dated Octcber That the setssic qualificatica of Auxiliary Feeduster (AFW) systems.

i letter outlined the continuing evaluation program being conducted by the staff with regard to this issue to assure confonnance of each plant f

As a with General Design Criteria 2 and 34, of Appendix A to Part 50.

result of the lutC's continuing review of this issue, including the completica of site vistts described in our previous letter, we have 1

determined that it is necessary to request certain information from PWR licensees and to request that certain actions be performed licensees, as described below.is to chtain sufficient information th AFW systems are seismically quallfled.

licensees perform a walk-dsun of the non-seismically qualified portions of their AFW systems to identify apparent and practically correctable deficiencies that may exist.

For plants with AFW systems that are not seismical of the systems in a timely, systematic manner to ultimately provide reasonable assurance, mhere necessary, that they This plan is a result of a Shutdown Earthquate (SSE) for the plant.

study of the seismic requirements which should be applied to AFW system 0667. "Transiefrt Response of Babcock and Wilcox I to this letter contains a request for inforr.ation from all operating PWRs concerning AFW system s'eismic design. -We have that docketed information from Ifeensees is not sufficient to a In addition.

t to conduct a detailed review of this aspect of AFV systems l

FurtM.we. since the nfety significance of the systera may not have been defined for all plants, the AFW system may not have been current.

adequately maintained and considered to be included within i

of IE BulletinsTherefore, the existing AFW systers, either in total or in part may have as-built characteristics which result in uncertain Notice 80-21.

seismic design characteristics.thereof which are not seismically qualif infortation concerning s'ystems which provide an alternate decay heat fi /

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removal path.

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, FEB 101981 s

W are also requesting that you conduct a walk-down by personnel experienced l

in the enalysis, design and evaluation of such structures, systems and c+-,xats, of the non-seismically qualified sortions of the AN system for the purpose of identifying more readily recognized deficiencies in seismic resistance. These walk-downs a m requested for only those p-ticas of the AN system dich have not been designed, constructed, ar.4 cz.intained as seismically qualified systems in accordance with the criteria for safety-grade sy:taus at the facility. The scope of the l

walk-6:wn should include the types of equipment, components, and piping described in Enclosure 2. describes what we consider to c:=; rise tfe bounds of the AN system, and any alternate decay heat removal paths.

For plants with AN systems that are not seiscically qualified, we consi.-

der that actions should be taken soon to ensure a reasonable level of earthquake resistance. This applies to both the AW system and the l

l attemate system used for decay heat removal if portions of it are not l

seismically qualified. Based upon the consideration of the past perfor-anace of nucleer and fossil power plants, and other pon-nuclear facilities subject to large earthquakes, we note that well engineered structures, equipment, components and piping possess a substantial amount of inherent ~

seismic resistance, even without the rigorous seismic qualification Of the performed for safety-grade portions of nuclear facilities.

failures of strvetures, piping, equipment and c+ wats noted in these past earthquakes, a large fraction have been due to brittle failure. lack of restraint large displacements, or some other obvious deficiency which would have been easily identified before the failure carsedby the seismic event. Such identified deficiencies could have been crn micd to significantly enhance reliability without detailedThese seismic analyses but by exercising careful engineering judgement.

consideratforts were factored into the development of Enclosure 2.

In additian, certain of these deficiencies were noted as existing at the several feel 11 ties for which we conducted AW system walk-downs (see for details of the visits). Accordingly, your walk-down of the non-seismically qualified portions of the AW system and other alternate decay heat renoval systens should identify any appropriate edifications in the context of the above discussion. identifies in sore detati the actions we consider appropriate for plants with AW systems, or portions thereof, that are not seismically Although we are not at this time requesting that the AN

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qualified.

system be sodified to be in conformance with the facility design seismic requirements, we have stated that cur plan is to increase the seismic ~

resistance, where necessary, to ultimately provide reasonable assurance l

that the system will function after the occurrence of earthquakes up to l

and including the SSE.

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Accordingly," tu h11Mng actions are requested by this letter:

1.. In accordance vita 10 CFR 50.54(f) of the Commission's regulations, all PWR licensees are requested to provide the information contained in Enclosure 1 within 120 days of receipt of this letter; and 2.

The results of any walk-downs are requested within 120 days of receipt of this letter. These results should include all identi-fled deficiencies ar.d all corrective actions taken, or planned along with the sche 61es for such. Such modifications, if any, shall be handled in the customary manner consistent with the prodstons of yo,e license and the Courission's regulations.

Responses should be stbsitted to enable us to determine whether or not your 11reens should be sodified, s pended, or revoked.

G. pisenhut Director rre Division of Licensing

Enclosures:

As stated "This request for information was approved by GM under a blanket clearance mauer R0372 dich expires November 30,1933. Cemeents on burden and skolication may be directed to the U.S. General Accounting Office. Regulatory Reports Review, Roon 5106, 441 G Street, N.W..

Washington, D. C.

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e Enclosure i RI""M T FCR INFORMATION AUI!LIAM FEE 00TER SE!SMIC DESIGN

!. --Ming to this letter, the AN system boundary from suction to discharge (including the water source and h:at sink) shall include those portions of the i,ys s required to accomplish the A.

system function and connected branch up to and including the second valve dich is nonnally closed er

---We of autoomtic closure een the safety function is required.

The W system boundary shall also include any portion of branch piping that is s,uvcturally coupled to the ATV systen boundary such that the seismic As a r-sw of the besech piping trans=1*a loads to the AFW system.

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, this includes the branch lines outside the AFW system boundary to c ::t t of three orc +.a1 restraints. All mechanical and electrical equip-wz...:,; ping (e.g.. instrument air) conduits and cable trays, which are r.:::::: y or contain items which are necessary, for the operation of the

~~~.: s:.;tsa shall also be considered.

In addition. the structures housing tm-systems and cogonents shall be included. Similar considerations

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s*41 oe applied when considering alternate means of decay heat reeeval.

Specify whether your AFW system is (a) designed, constructed, L

and usintained (and included within the scope of seismic related Galletins 79-02, 79-04. 79-07. 79-14. and 80-11, and IE Infgrun-tion Itstice 80-21) in accordance with Seismic Category I require-ets (e.g., conformance to Regulatory Guides 1.29 and the c;;11 cable partions of the Standard Review Plan or comparable criteria) or (b) designed, constructed and maintained (and included within the scope of seismic related Bulletins 79-02, 79-04, 79-07, 79-14, and 80-11. and IE Information Motice 80-21) to withstand a Safe Shutdsun Earthquake (SSE) utilizing the r-slytical, testing, evaluation methods ar,3 acceptable criteria w..sistent with other safety-grade systems in your plant. To 4.ssist the staff in an expedious assessment of your plant, if y::gr AN system.or portions thereof, is not qualified to with-stand an SSE utilizing the analytical, testing and evaluation criteria consistent with other safety-grade systems in your plant, we request that you identify those components and structures not seismically qualified in the appropriate row l

of the attached Table 1.

Wnere seismic qualification is indicated by leaving Table 1 blank, B.

provide a description of the rethodologies and acceptance criteria used to support your conclusion of seismic qualification, including:

Seismic analyses methods egioyed, seismic _ input, load cor-binations which include the SSE, allowable stresses, qualification testing and engi ieering evaluations performed.

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In addition, where seismic qualification of a secondary water supply or path is relied upon, provide a surrrnary of the proce-dures which would be folloed to enable you to switch from the primary to secondary source.

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If a lack of seismic qa=11fication is indicated for f teus 1. 2. 3. 4. 5 ad G, 7. or 8 in Table 1. provide additional information ditch spt:ift:; the level of seismic qualification afforded la the original & sign for each of these areas.

If substantial lack of seismic qualification is indicated for D.

items 1. 2, 3, 4. 5 and 6. 7. or 8 in Table 1. provide the saae taformation rettestM in A through C for any alternata decay heat removal systes. The bounds of these systems shall be considered to a similar exter.t as that described for the Provide a summary of the procedures by which arf system.

operation of thes,e alternate heat reoval systaus will be aceneplished.

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i TO.E 1 AIJIILIARY FEEMTER SEISMIC QUALIFICATION L

(1) Pumps /Ittors i

(2) P1P n9 (3) Valves /Actptors (4) Power supplies H

(s). Prtsary unter and scply path (6) Secondary Water and supply ratha (7) Initiation and Control System

(::) Structures Supporting or Housing these AFW System Items I

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• Applicable only to those plants where the primary water supply

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or path is not provided, however, a seissf cally qualified alternate E3 g

path exists.

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ENCLOSURE 2 i

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,ACT!aus REQUESTED OF MI5';'.':12E0 t

ETER REACTDR LICENSEE 5 n!!TrUT i

A SEISMICALLY QUALIFIED _

AUI!LIARY FEED W TER SYSTm i

l For ali L cnical and electrical equip =e.t and components including

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battery r.~.

c. ntrols, instrssents, cat:r:. cegressors tanks electe miies and the cabinets containing such items, note i

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all it:s rhien ere not securely attached to their supporting strv:1 a -d th:t there is substantial resistance to movement l

causet t-re::-ically induced forces.

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For pininc. noa cases dere relatively larga deflections cannot be accas==ani.ee without impatring system functica. ifhere such displetr~.ts vill leed to loss of system function, note where sufficies.t cm.:sts of restraint could be affordedJ thus signiff-cantly rti:ing stresses that would be imparted to such items as

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ping anzzias ar.d branch connections, as appropriate. F3rrther, note eccen:ric valve operators that are not sufficiently supported 1

and act to severiy overload the pipe. Icare such support is lacking, p :h: 1d note dere substantial restraints could be h to the extent practical. Also, dere pipes are resting om existir>g su~. L,. note where substantial resistance to the pipe movirs off these supports could be added where it does not already exist.

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For cchle trcys and conduits, assure that relatively large displace =c.ts can be acm=adated without impairing system l

functic i utscre seismic restraint is substantially less than required for these which are seismically qualified. Focus particulcr attention on preventing the breakage of the electrical and control cables they contain at such places as points of attacht of the cables to equipment or other relatively fixed point:. It:te dere any deficiencies exist.

Given the tiee frame we are reccamending for the cogletion of these actions, no' explicit analyses are requested to demonstrate system qualifi-cation unless dee=ed necessary by you. However, sound engineering judgerent should be applied considering the level of seismicity specified for your site and the design requirements for other seismically qualified

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systems in the facility when judging the necessity for and adequacy of any modifications (e.g., piping, cable trays conduit, equipment and

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Further.

wipceent restraints, and estimations of displacecent levels).

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these actions shall be acconplished using personnel who are experienced

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in the analysis, design and evaluation of such structures, systems ud l

i couponents.

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.a 2-e.ere you have deterstned that it is prudent to institute cedtfications, no modifications,should be (..atit.;*d dich will detrisentally affe:t the function of the piping, equipawnt and components of the systes:.

O considering all other loads in :dditt:a to seismic.

For exagle, when providing additional restraints to piping systems, assure that they do not have a detrimental tapact on tne system considering all loads, in addition to seismic includin; th:- :1 loads and support displacewnt induced loads.

Similar considerations as describec above should be given to other non-seismically qualified pt;:in, =tp Oent and conponents in the vicinity of the non-seismically

.itficd portions of the AN and the alternate decay heat removal svste.a-to provide for a substantial decrease in their susceptibilit.- to failure if such fatture could tapact the function of the AFJ and i.iternate decay heat receval systems.

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., e ENCLOSUC 3 REST,tTS OF NRC STAFF WALK-DO."tS OF AFW SYSTEMS Plant 1 - Seismically Qualified AFW System (Operating License issued in 1975) t l

Several locations were found in which the supports for the control-air for the auxiliary feedseter pe;.-s or for the auxiliary fee &ater control valve were disconnected frra their intended mounting locations.

These were examples of is;portant but non-essential systens (i.e., local manual control of the pumps and valves could be used if the air-system were damaged) which could be easily upgraded to increase the plants ability to remove decay heat following an SSE.

Plant 2 - Non-Seismicall Qualified AFV System (Operating License issued in 196 At least two supports to the auxiiiary fee & ster piping were either not connected to piping or not connected at the mour. ting location.

The bolts securing the auxiliary fee &ater unter supply tank (deminer-alized water trnk) to its pad were rusted and not tightened down Jf.e..

3/4 inch space between the support.and nut intended to hold it down).

Also, a long span of 2-inch piping was found having vertical supoort only to ditch lateral support could easily be provided.

Plant 3_ - Non-Seismic 411y Qualified AFW System (Operating License issued in 1967),

Three areas eere identified for which renedial actions could be imiemented in a reasonably shcrt time. The first of these was one of the station's battery racks. While the existing racks provided for some degree of lateral seismic and resistance, the configuration did not appear to have a level of integrity commensurate with the imortant of the batteries 3

to plant safety. These racks appeared flimsy in coccarison to those l

which wert installed to current seismic design criteria prescribed by the licensee for safety related systems.

The second area was the suction side of the Auxiliary Feedwater ptanps which consists of a single header from the condensate storage tank.

The header has some lateral support, however, the condensate storage j

tank was not qualified. The tank is not anchored at its base and the permanent alternate supply is through the tank. There is a capability to install a hose from a qualified eter source to the pump suction and bypTss the condensate storage tank. Keeping such a hose in place would enhance system reliability.

I The third area was the main instrumentation and control panels in the control room. These are supported at the bottom by a concrete channel and at the top by steel knee braces anchored to the concrete ceiling with expansion anchors. The requirements of IE Bu11ettn 79-02 had not

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2-Conformance with Men applied to these anchor bolts and base plates.

the IE Bulletin requirveents for the factors of safety and considering b:se plate flexibility for the original seismic loads uculd increase reliability. Also, some loose and missing screws were noted in these par.els which could be easily tightened and replaced.

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