ML20011B226

Forwards Guidelines for Demonstration of Deep Draft Pump Operability for Response within 30 Days as Suppl to FSAR Section 3.9.3.Long-term Operability Is Being Reviewed Per IE Bulletin 79-15

ML20011B226
Person / Time
Site:	Callaway
Issue date:	11/17/1981
From:	Tedesco R Office of Nuclear Reactor Regulation
To:	Schnell D UNION ELECTRIC CO.
References
IEB-79-15, NUDOCS 8112040645
Download: ML20011B226 (18)

Text

{{#Wiki_filter:- ~t a Dist. CDocWt' File bcc: LB'#1 Rdy ' TERA ~ j DEisenhut NRC/PDR 1 NOV 171381 BJYoungblood L/PDR ) Docket Uns.: STH 50 4R3 RLTedesco NSIC i and STN 50 486 MRushbrook TIC GEdison ACRS (16). JHopkins LOM g Mr. O. F. Schnell RVollmer Vice President - Muclear TMurley y h b(Jwyh' Union Electric Company RMattson /V Post Office Box 149 RHartfield, MPA N St. Louis, Missouri 63166 OELD T' t OV2 019815 q OIE (3) y O, v s, on

Dear Mr. Schnell:

~

Subject:

Long Tern Operability of Deep Draft Pumps a IE Dulletin 79-15, dated July 11, 1979, was issued to all licensees an I holders of construction permits as a result of deep draft pump deficiencies that were identified at facilities both operating and under construction. For pending OL applications, long tem operability of deep draft pumps is now being reviewed by the staff during the normal licensing review process, 4 In order to facilitate this review, enclosed is a document entitled, i l " Guidelines for Denonstration of Operability of Deep Draft Punps". Within 30 days from the issuance date of this letter, you should provide a schedule indicating when a response, in the fom of a supplement to FSAR Section 3.9.3, would be provided that discusses your assurance progran for demonstrating long tem operebility of your deep draf t punps and the extent to which it I. Enphasis should be confoms to the various portions of these Guidelines. j. placed on (1) the establishnent of installation procedures that are followed each time these punps are disassembled and reinstalled, and (2) the testing l requirements and bearing wear criteria. The instrumentation called for in the Guidelines should not be considered a requirement. These Guidelines establish an acceptable nethod of assuring long tem operability of deep draf t ptmps. They do not necessarily constitute the only nethod for denonstrating long tem operability. The staff wi11 ' review the information you submit to detemine whether your long term cperability l l assurance progran for deep draft purps is in sufficient confom6nce with these Guidelines to assure long tem operability. If not, the-staff will detemine whether you have established and utilized other nethods and procedures, preferably with the assistance of the pump nanufacturer, that l also demonstrate and assure that these pumps will perfom their intended functions for the 1ength of time required. ~ i l t OFFICE) sOAW ) PDR ADOCK 05000483 ~ ~ ~ ~ ~ ~ - ~. - ~ ~... ~.... ~... .... A PDR one> l knc ronu ata peo) Nncu cao OFFICIAL RECORD COPY - usam m,_m..

a 4 1 NOV 171981 If you have any questions regarding this natter, please contact Dr. G. E. Edison, the Licensing Project Manager for your facility. The application / reporting requirenents contained in this letter have been approved by the Office of Management and Budget; OMB Approval No. 3150-0011. Sincerely, Original signed by Robert L. Tedesco Robert L. Tedesco, Assistant Director for Licensing Division of Licensing Office of Nuclear Reactor Regulation

Enclosure:

Guidelines for Demonstration of Operability of Deep Draft Punps cc w/ enclosure: See next page J J I i i i i IL ri [ t .D.L..:.L..B. #.1.......M ' ..D...L.'Il. i D L f..L.4..... omec > ...E !.1,s.p.n./.y.t.,, BM,,,,1,p,os! 38g ,g,q,g,,,, G 5 .ua c e > ...../..),3../. 81 11/' 81 11 ......./. 9 /.81..... 11 ouap snc ronu sie po m uncu oua OFFICIAL RECORD COPY usam miem

Mr. D. F. Schnell Vice President - Nuclear Union Electric Company Post Office Box 149 St. Louis, Missouri 63166 cc: Mr. Nichols A. Petrick Mr. Fred Luekey Executive Director - SNUPPS Presiding Judge, Montgomery 5 Choke Cherry Road County Rockville, Maryland 20850 Rural Route Rhineland, Missouri 65069 Gerald Charnoff, Esq. Thomas A. Baxter, Esq. Mayor Howard Steffen Shaw, Pittman, Potts & Chamois, Missouri 65024 Trowbridge 1800 M Street, N. W. Professor William H. Miller Washington, D. C. 20036 Missouri Kansas Section, Mr. J. E. Birk American Nuclear Socie.y t ' Assistant to the General Counsel Department of Nuclear Union Electric Company Engineering Post Office Box 149 1026 Engineering Building St. Louis, Missouri 63166 University of Missouri Columbia, Missouri 65211 Mr. John Neisler V. S. Regulatory Commission Robert G. Wright Resident Inspector Office Assoc. Judge, Easter.n. District RR#1 Steedman, Missouri 65077 County. Court, Calliway County, M0, Route #1 Mr. Donald W. Capone, Manager Fulton, Missouri 65251 Nuclear Engineering Union Electric Company Kenneth M. Chackes Post Office Box 149 Chackes and Hoare St. Louis, Missouri 63166 Attorney for Joint Intervenors A. Scott Cauger, Esq. 314 N. Broadway Assistant General Counsel St. Louis, Missouri 63102 for the Missouri Public Service Commission Mr. Earl Brown Post Office Box 360 School District Superintendent Jefferson City, Missouri 65101 Post Office Box 9 Kingdom City,llissouri 65262 Ms. Barbara Shull Ms. Lenore'Loeb Mr. Samuel J. Birk League of Women Voters of !!issouri R. R. #1, Box 243 2138 Woodson Road Morrison, Missouri 65061 St. Louis, Missouri 63114 Mr. Harold Lottman Ms. Marjorie Reilly Presiding Judge, Dasconade County Energy Chairman of the Route 1 League of Women Voters Owensville, Missouri 65066 of University City, M0 7065 Pershing Avenue Eric A. Eisen,.Esq. University City, Missouri 63130 Birch, Horton, Bittner and Monroc Suite 1100 1140 Connecticut Avenue, N. W. Washington, D. C. 20036

1 ] Mr. D. F. Schnell ; 4 cc:..Mr. John G. Reed 1 Route #1 T ~ Kingdom City, Missouri 65262 ~ Mr. Dan I. Bolef, President ~ ~~ 4 Kay Drey, Representative Board of Directors Coalition for the Environment

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St. Louis Region 6267 Delmar Boulevard ~ e i University City,' Missouri ~ 63130 Si ' Mr. Donald Bollinger, Member. Missourians for Safe Energy 6267 Delmar Boulevard University City. Missouri ~ ~63130 2I:1'. Ms. Rose Levering, Member Crawdad Alliance 7370a Dale Avenue. ..e -e 2-St. Louis, Missouri. 63117 ::: - ~ 4 i l ^ 4 I i 3 h j w -.4.4.a, p

,J ,g g ENCLOSURE GUIDELINES FOR DEMONSTRATION OF CPERASILITY OF DEEP DRAFT PUMPS DISCUSSION ~

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'J : C..'. 1.E. Bulletin 79-15 dated July 1979, identified problems associated

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with deep-draf t pumps found at operating -f acilities and near tenn operating licensee facilities. Deep draf t pumps,yhich are al.so, called vertical turbtne pumps; are usually 30 to,60 feet in length' ~ ~~ with impellers located in casing bowls at the lowest elevation of the pump. The motor (driver) is located at the highest pur.p elevLtion with the discharge nozzle just below the motor. e-4 .~ Bulletin 79-15 was initiated because several nucl~ea'r/ power p1~ ant f acilities could not demonstrate cperability of their' pumps'. The ~ pumps were experiencing excessive vibration and bearing wear. The'~ rapid bearing wear suggested that these pumps could not-perform their required functions during or following an accident. As a result of the staff's initial review of the responses to IE5 79-15,. several plants were identif' led as having potential problems with their deep draf t pumps. These guidelines are provided for these ' plants so that the licensee or applicant involved mayhave a method acceptable to the staff.for demonstrating the operability of deep- ~ ~ draft pumps. e .. ij.. ~ D m,, A - m

a .. ~. ' - \\ DEEP DRAFT PUMP OPERATING CHARACTERISTICS In, order to better under, stand the. operating charac_teristics of 1 these pugs, a rotor dynamics analyses was perforrred,to ascertain the response of the pump. rotor under ste3@ state operation. The analyses considered journal bearing to shaf t,@namic respense at vari.ous eccentricities and fluid.v,iscosities.. The raadel for ..... - = the analysis depicted a typical deep draft pug utilized by. the nuclear industry. The analysis resulted in recor:mendation,s for iI:hroving the stabilit'y 6f' tiie pump rot'or from exteFnally applied ^ ~'~M- ~' inputs and by self-g'eneHted inputs. ' The conclusions which were derived from the analysis and staff evaluations of North Anna, Beaver Valley and Surry facilities with similar pups include: 1.) Pugs with this type of configuration are prone to bearing whirl vibration problems due to the flexibility of the rotor and casing structure. This phenomenon is accentuated as journal bearing clearance beco:es large. This phenomenon. leads to bearing wear (Journal bearings). a 1 "1.ow Head Safety Injection Pug Rotor Dynamic Analyses", by Franklin Research Center Report FC4982, dated May 1980. I I

m l 2.) There may be natural frequencies associated with the pump assembly which occur near the operating speed of the pump..._ Pump operation will drive these frequencies and can cause bearing' wear. The severity of, this condition is dependent.,-. on bearing diametral clearance, rotor unbalance conditions and housing flexibility. s an example, if the wear in...... column journal bearings becomes sufficiently large ~ ( twice the original diametral cl earance)'so that these' bearings are no longer active and the undamped., .z. critical frequency near the operating speed of the pump, 2 is allowed to expand, the additional uncontrolled bearing wear will occur. Th.is wear can continue until the shaft rubs against the support structure of the bearing and can e potentially sever the shaft. 3.) One acceptable method for correcting instabilities in the pump shaf t is to utilize a journal bearing design which exhibits stable characteristics. 0.ne such design is the

• Taper land bearing". This design is more stable than the plain journal bearing, is less susceptible to wear because of the taper and will cause the bearing to fem a hydro-e l

dynamic film quickly during startup. e e be e ep*, ya e a, e eO e m'

r. ~4~ --3 1 t 4,). Stiffening of the column sections of the pump is advantageous if there is a column frequency near the ... operating speed.of the pump,. The ; shifting of the _. column frequency to a higher level will eliminate ' ....,, any coupling.between the pump operating speed and the r- ,g .coluen frequency. .5. ) Flow. in'let c_ondi tions,to the pumps and st. p designs can .be.impor. tant,to pump o,perability.~ Certain installations .have demonstrated flow characterist'es wtiich produced ~ vortexing at the be11 mouth of the pump. This vortexing ~ " ~ is due to sump design or sump supply line entrance con-ditions. This condition can contribute to additio.nal pump vibration and wear.. Flow straightener devices, reduction of be11 mouth diameters, and bottom clearance reductions have proven to be effective in eliminating this problem. 6.) This type of pump has exhibited operational problems ) due to design and installation deficiencies. The high ~ flexibility of the shaf t and column make this design rather forgiving when it cemes to insta11ation deficien-cies such as misalignment between the shaft and column, d t M

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low-precision coupling assemblies, and non-perpendicular,, This fact however, can lead to excessive mounting' fl anges. bearing we'ar without-significant.notic,eable change in pump operating characteristics. :To ensure proper pump operation, prop'er aligr. ment shoul'd be established betyeen all mating ~ surf a'c'es and measdres 'should be. emphasized which pre {ent colum and'shaf t eccentricitt'e's. These measures can include optical aligi. ment of-the ~ column segments, use of high precision l couplings and use of ac' curate-techniques to.estab1_is, that ~~ h the~ sump plumb line is perpendicular to the pump mounting ~ fl ange. The above findings ayd conclusions have contributed significantly The guidelines listed to the development of these guidelines. The subjects below are divided into installation and test areas. to be addressed in these areas are considered to be of ' prime importance when establishing a pump cperability assurance program. The extent to which each of the two are'as are implemented at a specific facility is dependent on specif1c symptoms which have been identified with these pumps while in operation and* during service periods. e .~,....:... s - w on.~- "H--

1, a 6- ,'.Ir.ple=enting the' measur'es cutlined below, at North Anna 1 & 2 in ~ ~ ~ ~. total,'has been shown to provide reasonable assurance that the pumps i ~. ; % . will be operable when required for their safety function. These ~ guidelines are 'not intended' to ' replace' the requirements of Standard Review Plan 3.9.3;~Regblatory Gui'de 1.68 or any other u........: - J. requirements presently enforced by the staff. Rather, the r

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guidelines are to-be used 'as~sdiplementary material for establishing

. deep-draf t pump; operability.. ~ GUIDELINES FOR OPERASILI'Y INSTALLATION: T ..x.c. . f. 1~. 0 INSTALLATION PROCEDURES ~2 ~ Experience has shoc that these, pump.s.a.re_ prone to.having operability problems a3' a result of poor installation proced,ures. The guidelines ~ emphasize those areas of the installation procedure,which if implemented ' ~ i could significantly improYe the likelihood of an operable pump. The procedures utili:ed should be submitted to the staff for review. i 1.1 pump INSTALLATION Determine by measurement that all shaft segments are straight a. 'l within tolerances specified by' the manufactur'er. ~ 6 b. Detemine by measurement or provide certification that all 1 couplings (for shaft segments & ' pump to motor coupling) are, " of high precision as specified by the manufacturer. Detemine by measurement that all pump segment flanges are c. perpendicular to the centerline of the segment, that the segments are straight and that' any mating surfaces are. concentric to an established datum. Tiere fournaf " ' ' o

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. m , bearing guides (SPIDERS) are used, establish: con'- -. ~n: :f centricity.between this asserbly and its rating surface.

d.. Align full pump casing. assemb y opt cally to' assure-l i

maxicum straightness and. concentricity of.the:asse:bly'. C Any equivalent cethod is acceptable, as long as the procedure stresse's. column straightness 'and: concentricity.} 0 ' Assure pucp.to motor' flange perpendicularity and tiiat ^ ~ e. proper coupling installation-is perf orne~d. f. Assure that ^all mating surface bolting is properly attached and that ranuf acturer torquing sequences are adhered to.. .i .- i '- ~ ~~ n ;- 1.2 SUMP INSTALLATION a. Assure (where used) that sump /purp r.ating flange is perpendicular to the surp pump line. b. Assure that sump design prevents fluid anomalies such as vortexing or turbulence near the intake to the pu=p bellmouth and that incoming piping is not so designed as to allow fluid conditions f avorable to these anomalies (i. e., sharp. ' bends in piping prior to entrance. into sump). c. Assure that interference does 'not exist between the sump and ary pump appendage such as a seismic restraint. .,. _ g. e 4 O l

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. l 2.0 Testino Recuirements The installation procedures are essential in establishing pump

~ ~ ~ ope'ra'bility. 'In adEition' to careful installation, testing may e be required which'will verify proper operation of these pumps. Af ter cogletion of ' the installation ' checks, licensees or appli-p cants should evaluate the need for further testing and report the.results of this e'valua' tion "together.with the details of any ~ ~ ' test plans to the staf'f. ~~5houl'd lesk.s be required, an acceptable ~ test procedure shou d include' the iteb listed.hslow. The staff 3 recoenizes that the instrumentation and procedures outlined below. may be difficult to i:rplement at al f a'cilities and,' theref 5re', the ~ staff is eghasizin~g good installation practices which lead to operable cogonents. If tests demonstrating operability cannot encogass all the items listed below, then alternative procedures should be proposed for evaluation by the staff. Thetes[tsshould eghasize reasurement of pug ' dynamic characteristics and wear data at dif ferent stages of testing, culminating with an extrapolation of the data to the desired life goal for the pump. 2.1 Test Instrumentation The following instrumentation should be incorporated into the test procedure aside from nor:nal flow measu'rement, pressure and vibration instramentation: e 4 e e e: ec e . 1

a g. a;) X, Y proximity probes at three axial locations on the pump column, for measuring and recording ~ radial positions-of shaf t with respect to the column. b.) X, Y, accelerometers (at proximity probe locations) for measuring and recording radial accelerations of the column. ' c.) Dynamic pressure tr.ansducers for measuring fluid pressure 'at the following locations ;- u. ~ 1. Bottom of Column (suction) e . 2...Mid-Column

3. :. Top of: Column. ; _ - -

d.) Shaf t Rotational speed,and dynamic variation instrument. t-2.2 PRE-TEST DATA With the pump disassembled, measure all jcurnal bearing 0.D.'s, bearing 1.D.'s and calculate bearing diametral clearances. In - addition with pumps fully assembled and using the proximity probes, .obtain the " clearance circle" at each of the three axial stations by ' rolling the shaf t section within the clearance volume of"its bearings and in this way, establish proper operation of the probes. y,- '.e* ~ e.. eo t ~ ~ _. _ -+4-

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e, ' e - ~. ; t. PNASE 1 Testing (6' hours plus start-stop)g. ~ 3.1 .3 H.. .. -3, c;r.. ;. 5 This phase of testing should be comprised of 6 hours of testing (Break-in) followed by start-stop testing. TTest ~~- conditions should simulate as nearly as,possible normal and accident. conditions. :. Parameters: to be considere'd ~ are flow,:temperatur.e, debris, and chemical camposition of fluid being pumpe.d. : Static ' torque te' sis 'shoQ1if beH2 performed before'and after the test (i.e. measure amount of torque' requir.ed to turn shaf t by hand). Data should be taken durin.g.the six hour test at 1/2 hour intervals. A total of 12 start-stop tests. will be performed con- ~ sisting of a start up frcm zero speed up to full-speed, 10-minute dwell at full-speed and a shutdown from full speed to zero speed, with recording of all instrumentation during full cycle of start-stop. Upon completion of Phase 1 testing,the folloying data should. be obtained and recorded: I 1.) Obtain the ' clearance circles" using the hree sets of proximity probes. l 2 Tests at North Anna 1 & 2 and Manufacturers input indicates that 6 hours is an adequate time interval for bearing " break in pe riod...... I h

,2.) lieasure and record the following dimension: for each bearing: a.)... Journal 0.D. ~ b.) Bearing I.D. ~ c.) Bearing to Journal diametral clearance ~ ' ~ d.) Establish Phase 1 test bearing wear. ' ~ ~ ~ ~ ~ = ..--,--~ THE ACCEPTANCE CRITERIA 15 AS FOLLOW 5: ~ 3 1.) If wear is)* 5 mils for any bearing, wear is unacceptable ~ ' ' ' ~ and test -shculd be terminated. ' ~ ~ ~ 3 - ~ ~ " ~ 2.) If wear is( 5 mils fcr all' bearings

a. ) Reasse:ble the pucp

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b. ) Obtain " clearance circles"

c. ) Reinstall pump in test loop. ~-

2.4 Phase 2 Testing (48 hours) Phase 2 testing is to be performed at full system pressure. and temperature and fluid conditions sfrulating those expected during accident and normal operation. Before start and at completion.of Phase 2 test,obtain reasurement of static torque. Data should be recorded continucusly during the start-up period, 3This acceptable wear value may be codified based on manufacturers recommendation. ~ ....c 4 L w* 1

6 12 - and during the shutdown period. Data should 'al'so be recorifed - .'~ ~~ ~ at 1-hcur time intervals during the 48 hour test'. ~ ~ ~- The following -measurements should he made at the conpletion. 2 of' Phase 2 of i. lie test:' Obtain the " clearance circles" using the t,hree sets of, ~ -1.) ~ ~ proximity: probes. - Measure.and. record the-fo11'owing dicEnsions.forleach,,, 2.' ) bearing:' J ~ a.) 4cu rnal.0.0.- 'b.) Bearing:I.D.-

c. ) Bearing-to Journal diametral clearance.

d.) Establish accunulated bearing wear. THE ACCEPTANCE CRITERIA IS AS FOLLOW 5: If accuculated bearing wear on any bearing is 1.) >7 mils, wear is unacceptable and test shculd be termi nated. 2.) If accuculated wear.on all bearings isd7 mils' forallbearings@. / a.) Reassen-ble pung

b. )

Obtain " clearance circles" ./ ' c.) Reinstall pump in test loop.

l ...t e.r ~ _ 13 ~-. } / 5.) Phase 3. Testing (96 hours)

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~ - ~ ' Phase 3 testing is to be perfomed at full system pressure 4 3 7. .- arid temperature and fluid conditions simulating thos'c expected.. ~ ~ s'. ! { during accident and normal operation. The same procedure 55.' J~~ J2 .T ~ e _ should be follo'wed as in. Phase 2. testing eEc~ept thate dataT. ~i.l_ ~1 ' ~ Z._I may be taken with less frequency. ' ~~' ' I t ' The same measurements should be taken ~at the'c..pletion of f ~ 7- _ _ _. _. this phase as wi'th the other phases with the following acceptance i' -... ^- - s -criteria: ~ ~~ em ~ __ _ 7_. 1.' ) If accumula ted b' earing 5ea~r'is > B mils for.any,b'earingr 4 ~~ ~ ~ c wear is unacceptable and test should be tercitiited. i ~ n c t 2.) If accue.ulated wear is ( 8 mils for all bearings,# ~ e " ^ a c. decision needs to be made to establish: 3 s - n '" J ' ',. x yw s a.) the need for additional testing or .,}, a ,, ~. y r b.) whether or not the bearing wear will be acceptably ' ~ l ow. x- .QJa : ,ng y The recommended decision process is outlined below. 'x s L \\ ~ ~ 'N f Plot the values of accumulated wear versus time (H) for eac s / ?. T, s bearing af ter Phase 2 and Phase 3 tests,' namely. T l" Wear at H2 = 54 hour g W o e Wear at H3 = 150 hours 4 s. i l g

s, ,;",. s, ,a s s.. ~ o s 1 s 14 _ s, 1 ss

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}. u, Straight lines'(a're th6c drawn through the plotted values of wear s s. and extended to the'right (See example Figure 1). If the extension intercepts the maximum acceptable value of wear (8 mils) at a value x[' li les s thin th' goal for this pump, additional testing should ~~ the interc'ept of the line with wear of 8 mils be perfomed.. ..4 .; ; 2 . ---. exceeds the.l.ife.. goal for '.this pump, no additi.onal testing is _. 2.. .;. -, 17. n c required.and bearing we.ar is acceptable. If addition.a1 testing ..2_ s .p. . a :.- is deemed necessary it should be done in a similar manner to that = C... perfomed during Phase.3 with similar acceptance criteria and .g... decision process. It is eipected that such additional testing ' wil1 either show a stable pump opera' tion with no increase in ~ bearing wear or incre.ased bearing wear with unacceptable results. _= w 2.6 Evaluation of Pumo Acceptability If bearing wear (af ter all' testlng phases) is acceptabky 1 (as per decision process) and if vibrhion levels over the frequency spectrum of 3 cps to 5000 cp: areL acceptably low and show no unfavorable trend of increasing magnitude during the tes't;pg,: the4 pump may be judged acceptable for its titended use. \\ N h ' 3 I s, l s 9 r g *,, 3 \\ s. s \\ s T 4, v,- .n

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