ML20118B607

Forwards Responses to Piping Design Audit Open Items A-10, A-17 & A-28

ML20118B607
Person / Time
Site:	05200001
Issue date:	09/11/1992
From:	Fox J GENERAL ELECTRIC CO.
To:	Hou S NRC
References
NUDOCS 9210050222
Download: ML20118B607 (17)

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GE Nuclear Enctgy September 11, 1992 Mr. Shou Nien Hou 7F21 U.S Nuclear Regulatory Commission 1155 Rockville Pike Rockville, MD 20852

Dear Shou:

Enclosed are the responses to Piping Design Audit open items A-10, A 17 and A-28.

Il you have any questions please call me (488-925-4824) or Maryann Herzog (408-925-1921).

Sincerely,

,.h b k N. Fox Advanced reactor Programs cc:

Chet Poslusny (NRC)

Giuliano DeGrassi (BNL) 1/ '

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GE-!!E ABWR PROGRAM MECllA!!ICAL SYSTEM DESIG!I FILE Mll-A10 DISTRIBUTIO!1:

J DK, J f1F DATE: SEPTEMBER 8, 1992 TO : M llERZOG FROM: 11 L HWAliG N

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SUBJECT:

AUDI'I ITEM A-10 EXPA!1SIOli At1D CollTRACTIO!1 OF ADJQ, RV1 A11D OTilER LOADS.

1) Safety Relief Valve Discharge Load The contraction and expansion of the time history is equivalent to reducing and increasing the load. The calculated results compare well with the test data performed at Wyle which was provided to liRC and B11L in the meeting *. It is not necessary to reduce or increase the load.

2) ADJQ and Other LOCA Pool Loads.

The condensation oscillation load have been discussed in the meeting and agreed that the load used for analysis is conservative.

The next important load is ADJQ.

The current input frequencies are at 5.8, 8.12 and 11.3 11 2. The majority of the load acts on the quencher arm and the quenchor body. The lowest natural frequency of the quencher arms and the quencher body is 52 IIz.

There is only a small portion of pipe near the pool surface has natural frequency of 12.2 li z. This indicated that the response of the quencher and pedestal are not sensitive to the frequency variation of the input.

Therefore, it is not necessary to expand or contraction the Lime history loads for the analysis of the wetwell pool loads.

July 28, 1992 through July 31, 1992

s _ _ _... _ _ _ _. _ _ _ _... _ _ _ _, _. _. _ _ _. _ _. _ _ _ _ _

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GE-NE ABWR PROGRAM HECilANICAL SYSTEM DESIGN FILE MH-A17 DISTRIBUTION:

f JBK,JNF DATE: SEPTEMBER 11, 1992 r

TO : M HERZOG FROM: H L HWANG NM

SUBJECT:

AUDIT ITEM A-17 THERMAL STRESSES DUE TO FEEDWATER NOZZLE STRATIFICATION STRIPPING EFFECT The temperature gradient stresses due to stripping has been included in the current thermal duty cycle charts. The stripping occurs during i

hot standby. Attached Figure 1 shows the hot standby event. This figure shows the requirement to calculate the temperature gradients due to step change from 132 to 99 degree C and back from 99-to 132 degree C.

Using 2% rated flow during hot standby the calculated temperature gradients ranges from the cycle are as follows*

132-99= 33 deg. C Step

= 59.4 F DT1 range = 35 deg F.

DT2 range = 12 deg F DTAB range = 29 deg F Although the temperature transients step change of 59.4 degrees is-T not exact the same as the data measuremed from-the plant, but the net i

results are about the same. Based on Leibstadt plant measureed data the maximum temperature change on top of the nozzle is from 375 to 135 degree F in 3.5 minut(3. The temperature change at bottom of the nozzle is less than 1/3 of the top of the nozzle.

The worst assumption is to assume 375 to 135 and back to 375 cycling.

The temperature = gradients time history due to the stripping effect has been calculated. The results are plotted in Figure 2.

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temperature gradient ranges are as follows:

l 375-135= 240 deg. F in 3.5 minutes.

1 DT1 range = 39 deg F.

DT2 range = 23 deg F DTAB range =

7 deg F i

This shows that the temperature gradients calculated from both cases.

are about the same. The allowable fatigue cycles for the' alternating stress from either case are more than 1000,000 cycles.-

This concluded that the current - feedwater duty cycle requirement is

-adequate for the stripping effect.

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GE NE AllWR PitOGRAMS MECilANICAl SYSTEMS DESIGN FILE: Mll A17 DISTRII3UTION:

JBK; JNF:

DATE: SEPTEMBER 9,1992 TO: M ARYANN llERZOG FROM: E.O. SWAIN h.

E d/f. G'/bt f(

SUBJECT:

AUDIT ITEM A CRITERIA FOR CONSIDERATION OF STRATIFICATION Delete the third paragraph in 3.9.3.1 and replace with the parag ah below.

The present third paragraph erronously states that Table 3.9-contains predicted loads and stresses which are compared with allowables. Since predicted loads and stresses are not available this paragraph needs to be deleted. A copy of SSAR Page 3.918 showing the Audit item A 17 change is utached.

New third paragraph in 3.9.3.1:

Thermal stratification of fluids in a piaing system is one of the specific operatine conditions that is included in tie loads and load combinations that are contined in the piping design s?ecifications and design reports. It is known 7

stratification can occur in the teecwater piping during plant startup and when the plant is in hot standby conditions following scram (See Subsection 3.9.2.1.3). If, during design or startup, evidence of thermal stratification is 3

detected in any other piping system, then stratification will be evaluated, if it cannot be shown the stresses in the pipe are low and that movement due to bowing is acceptable, then stratification will be treated as a design load. In general, if temgerature differences between the top and bottom of the pipe are less than 50 F., it may be assumed design specification and stress reports need not be revised to include stratification.

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hermal stratirication of nuids in a piping spiem is one of ABWR

~,P-in< er-in, tendaiea, ihat i, ia< iud.d in ihe i d.

• $3ndilrd $nt and load tombinations that are runtined in the piping design N

$periritatiunt and design reports. Il in knnan stratiritation can N,

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The resuit5 of Ihe. data analyses, sibtation

• crar in th' f**daaur PiriaC ulia2 P ant artvP and w hen the g

P ant 15 in hat Stuadh> conditi"as f"Ilo=ia: $ tram (see l

amplitudes, natural frequencies, and mode shapes are then compared to those obtained from the Sia'oio" Mi 4 If, du'ian d'5 ira or anur. **id'ar' '>f theoretical analysis.

'he' mal s'ratifica'iaa is d'kr'ed sa aa) other piping spiem.

y then soatifitation wiH be esaluated. It it cannot lee shown the

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Such comparisons proside the analysts with P

• y added insight into the dynamic behavior of the

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la"d-la E'a"al if 'emp raiure dirrerencei t.<t een the top reactor internals. The additional knowledge q

"ad b"'"'"' "' "" P P' d'e leu than 50 l' it may be muumed i

gained from previous vibration tests has beea utilired in the generation of the dynamic mod:Is d" 4'" 'P" *"6"a a"d $"*

" P""' "d a6' b' "'id

for seismic and loss of coolant accident (LOCAN

'ad"'"'""'a6 a-l Th: d:sigo life for it: ABWR Standard F.:::

analys:s for this plant. The models used for this plant are similar to those used for the is 60 y:a rs.

A 60 y:ar d: sign lii:

is a vibration analysis of earlier prototype BWR

quir =::t for all =aj:t plant ::= pen::ts ma plants.

r:ase :soi: expection of =:: tic; this d:U;:

.if:. However, all piant cper:. tic:si ::=:en::tt 3.9.3 ASME Code Class 1,2, and 3 and :quipment ext:pt the r: actor v:ss:i at:

Components, Component Supports, and c:ug::d to be r:piac:abi:, desi; lif: ::t Core Support Structures withstanding. The deng lif: r:quu:=::t allows f or ref urbishment and r:: air. as 3.9.3.1 leading Combinations. Design appr:priate, to assur: th: d:s:;n hi: ef.:

T ransients, and Stress 1.imits ov: ail p1a nt is a::ie v::.

Io :if: t

.s::ttally all piping syst:::

co=ron::ts and This section delineates the criteria for eculpm: t are desics:d for a 60 year d:n::

selection and definition of design nmits and

'.i[:. M ay of t b:s e c o r= p o = = t s a t : classiF5:

loading combination associated with normal as ASME Class 2 or 3 or Quality Group S operation, postulated accidents. and specified,

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,N seismic and other reactor buildinc vibratien I

=my m::.a.ng c.ws:m; ne::wn a::a : : : m:. ~:n.cm

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(RfW) esents for the design of saf:tv related y a me;nasu :n, cr :.a=:n n w er e=

- ~a ASME Code components (except containmr nt N

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l components which are discussed in Section 3.9. ;, :;n::nis rere?cncmg :ne AD*m :tt;n d. acw n:t

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p This section discusses the ASME Class 1. L ' ; """"'# # ~ 3 '" F"'"" # ' #i" *' " # # " ~ "

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and 3 equipment and associated pressure retaining r ""' '" ##i' "Y T'#"";""'" * " ~#*

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pa r t s a t; d id e n t ifie s t h e a p plica ble lo a d in g s. p ';=" "' 3r 'h kt2 ""r'r ' 'I c! "~ ~ ~ ~ J " 7'# '

calculation methods, calculated stresses, and f re

'emc-allowable stresses. A discussion of major yan um:! unres nave urn swuu: m unt=m e m equipment is included on a component by component jI P.U7t. t h comocarnts. :nen cr uie c cure a e :, : f=nr

'y basis to provide examples. Design transients and I cama ass ouraov veen permmed. ; co:ng u:e c:-nwu u I

--x dynamic loading for ASME Class 1, 2, and 3

a:;-ca u s: e not c=ar cec =nc 6c:=n c== v =W equipment are covered in Subsection 3.9.1.1.

mem : recents m ine pipe n o.1 m Errus:t ry m : car Seismic-related loads and dynamic analyses are cn:=n c a :nai a =s:gne: w nc : u::mit n in=a : c =

l discu:, sed in Section 3.7. The suppression

,,e.c y cc yg, c.7c,,nce: p c;=: 4 ppm; nzac cur:n-w

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pool-related RBV loads are descri8md in Appendix

38. Table 3,9 2 preser.ts the combinations of 3 9 311 Pl'nt Conditions dynamic events to be considered for the desica and analysis of all ABWR ASME Code Class 1,3, A!! ev: ts that the plant will or m:;ht i

and 3 compont.1ts, component supports core cr:dibly exp:ri:nce during a r:a: tor year :::

support structures and equipment. Specific es aluated to establish desi;:: basis for pa:::

loading combinations considered for evaluation of equipment. Th:s: events at: divid:d into f::t l

each specific equipment are derived from Table plant : c o d i t i o.: s. The plant cocett:00s 3.9-2 a n d a r: co nt ai= = d in t h e d e si; :

d:s:ribed i:: the following paragraphs at: :n:d specifications and/or design reports of th:

oc :v:::t p r ob a bilit y (i. e., f t: q u

• n *- Of resp::tiv: :quipment. (Se: S ubs:: tic:: 3.9.D oc:urreac: as dis:ussed i Subs:ction for COL license information) 3.9.3.1.1. 5 ) and correlat:d to servie: !:\\ -is Amendment 2t jg ggj jjgj;$ fg[jngd :: the ASME Boil:t 3:d Pr:ssur: Vessel Code 5:ction ill as shown in Tabl:s 3.91 and 3.94 3 9-18

i G E-NE ABWR PROGRAMS MECilANICAL SYSTEMS DESIGN FILE: Mil A28 DISTRIBUTION:

JBK; JNF; DATE: SEPTEMBER 1,1992 TO: MARYANN llERZOG FROM: E.O. SWAIN SLfBJECT: AUDIT ITEM A 28 - FEEDWATER STRATIFICATION MONITORING PROGRAM Below is my recommended addition to 3.9.2 to cover Audit item A 28. This addition consists of a'new paragraph beginning on Page 3.9-7, see below, and as shown on the SSAR markup of pages 3.9#and 3.9 8. I will make recommendations for additions to Chapter 14 the subject of a separate letter. ( se c.

te Re,- d o4cel 9A /92.)

t 3.9.2.1.3 Thermal Stratification in Feedwater Piping This is a special test to be performed as part of the startup program to monitor the conditions and effects of temperature stratification that may exist during certain operating conditions in: (1) the feedwater piping header inside and the pipi,ng outside containment, and (2) the short horizontal runs of the riser piping inside contamment where feedwater enters the vessel nozzles.

Stratification in the Dedwater piping can occur during plant startup when hot RWCU is added to the cold teedwater line. The hot RWCU flows on top of the colder water in the feedwater line and does not mix with the colder water until mixing of the two stream occurs at the outer swing check isolation valve. Stratification for this condition can thus effect only the feedwater piping outside containment.

A second condition of plant operation ivhich can cause stratification in the feedwater piping is when the plant is in hot standby condition following scram. After scram, the-temperature of the entire feedwater line is hot. When cold water is introduced to make up for decay heat boiloff in the RPV, the colder water flows along,the bottom of the large -

diameter horizontal feedwater pipe at low flow rate, creating stratification. Tfie temperature difference between top and bottom of the pipe will decrease along the pipe in the direction of flow, but stratification could still exist in the feedwater piping inside containment since the swing check valves are not effective in mixing the cold water flowing along the bottom of the-pipe.

The test program will consist of measurement of(1) temperature around the circumference of the feedwater pipe at various locations inside and outside containment, (2) strains at points of highest stress inside containment, and (3) measurement of pipe displacements and movements'inside and outside containment due to pipe bowing because of stratification.

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This test will be performed in accordance with the general requi ements of Regulatory Guide 1.68 and the more specific requirements in ANSI /ASME OM7. Detailed test procedures will be prepared in ac:ordance with these documents. The development and specifications of the types of measurements required, the systems and locations to be monitored, the test acceptance criteria, and the corrective actions that may be necessary are as discussed in Paragraph 3.9.2.1.2 Thermal Expansion Testing.

The feedwater thermal stratification test is not required if the applicant can show a test performed at a previous plant meets the requirements of this paragraph and is applicable to his plant.

. ABWR mmt Standard Plant-nrv n I

cilitate assessment of the test while it is in noted should be accounted for in the criteria progress. Limits of thermal expansion displace-limits including possible reanalysis.

ments are established prior to start of piping testing to which the Lctual measured displace.

Si ould the investigation of instrumentation ments are u apared to determine acceptability of and criculations fail to reconcile the criteria the actual motion. If the measured displacement violations or should the visual inspection re-does not vary from the acceptance limits values veal an unintended restraint, then physical cor-by more than the specified tolerance, the piping rective actions may be required. This might in-system is responding in a manner consistent with clude complete or partial re:noval of an interfer-the pred4 ions and is therefore acceptable. The ing structure; replacing, readjusting or reposi-t piping response to test conditions shall be con-tioning piping system supports; modifying the sidered acceptable :f the review of the test re-pipe routing; or, modifying system operating pro-sults indicates that the piping responde in a man-cedures to avoid the temperature conditions that ner consistent with the predictions of the stress resulted in the unacceptable thermal expansion.

e report and/or that piping stresses are within ASME Code Section 111 (NB.3600) limits. Accept-3.9.2.1.3 Thermal Stratification in Feedwater Piping i

able thermal expansion limits are determined after the completion of piping systems stress This is a special test to be performed as part of the analysis and are provided in the piping test startup program to monitor the conditions and effects sp e cifica tion s.

Level I criteria are bounding of temperature stratification that may exist during criteria based on ASME Ill Code stress limits.

certain operating condition in: (1) the feedwater piping Level : criteria are stricter criteria based the header inside and outside containment, and (2) the predicted movements using the calculated deflec-short horizontal runs of the cf the riser piping inside tions plus a selected tolerance.

containment where feedwater enters the vessel nozzles.

3.9.2.1.2.4 Reconciliation and Corrective Ac.

tions Stratification in the feedwater piping can occur during plant startup when hot RWCU is added to the cold l

During the course of the tests, the remote feedwater line, the hot RWCU flows on top of the measurements will be re;ularly checked to verify colder water in the feedwater line and does not mix compliance with acceptance criteria. If trends with the colder water until mixing of the two stream indicate that criteria rnay be violated, the mea-occurs at the outer swing check isolation valve.

surements should be monitored at more frequent in-Stratification for this conditica can thus effect only the tervals. The test will be held or terminated as feedwater piping outside contain nent.

soon as criteria are violated. As soon as pos-sible after the test hold or termination appropri-A second condition of plant operation which can cause ate investigative and corrective actions will be stratification in the feedwater piping 's when the plant taken. If practicable, a walkdown of the af-is ir ;ot standby condition following scram. After i

fected piping and suspension system should be scram, the ternperature of the entire feedwater line is 3

made in an attempt to identify potential obstruc-hot when cold water is introduced to make up for tion to free piping moveme::t. Haugers and snub-decay heat boiloff in the RPV. The colder water flows bers should be posi:ioned within their expected along the bottom of the large diameter horizontal cold and hot settings. All signs of damage to feedwater pipe at low flow rate, creating stratification.

piping or supports shall be investigated.

The temperature difference between top and bottom of the pipe will decrease along the pipe in the direction Instrutnentation indicating criteria failure of flow, but stratification could still exist in the-shall be checke~ for proper operation and calibra-feedwater piping inside containment since the swing tion including comparison with other instrumenta.

check valve are not effective in mixing the cold water tioa located in the proximity of Ihe flowing along the bottom of the pipe.

out-of bounds movement. Assumptions, such as pip-1 ing temperature, used in the calculations that The test program will consist of measurement of (1) l generated the applicable limits should be com.

temperature around the circumference of the pared with actual test conditions. Discrepancies feedwater pipe at various locations inside and outside j

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ABWR Slandard Plant 11A610rff pre n containment, (2) strains at points of highest stress inside containment, and (3) measurement of pipe displacements and movements inside and outside containmen' due to pipe bowing because of stratiScation.

This test will be performed in accordance with the general requirements of Regulatory Guide 1.68 and the more specific requirements in ANSI /ASNIE 0517.

D: tailed test procedures will be prepared in ar-

-d

- - ' h these documents. The development ns of the types of meesurements re gt.a c, ms and locations to be monitored, he teo criteria, and the corrective actions sary arc as discussed in Paragraph

<pansion Testing.

acrmal stratification test is not h

applicant can show a test performed at a previous plant meets the requirements of this paragraph and is applicable to his plant.

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i G E-NE ABWR PROGRAMS MECilAN! CAL SYSTEMS DESIGN FILE: MII A28r DISTRIBUTION:

JBK; JNF; DATE: SEPTEMBER 4,1992 TO: MARYANN HERZOG FROM: F. Q. SWAIN it

SUBJECT:

AUDIT r d A FEEDWATER STRATIFICATION MONITORING PROGRAM CHAPTER 14, SSAR Below are my revised recommendations for changes to Chapter 14 to add the feedwater stratification monitorine program. This letter supplements my letter of September 1, on changes to Section 3.9.3hf the SSAR on the same subject. SSAR markups are attached.

1. On page 14.2 59 Replace "14.2.12.2.10 System Expansion" with:

14.2.12.2.10 System Thermal Expansion and Feedwater Stratirication.

The movement of piping systems due to thermal expansion and fluid te-mperature stratification is momtored during the start up test program. The thermal expansion test program applies to those piping systems identified in Paragraph 14.2.12.2.10.1 (3). The fluid temperature stratification test applies only to the feedwater piping.

j 14.2.12.2.10.1 System Thermal Expansion

2. Add new paragraph to cover the feedwater stratification test as follows:

14.2.12.2.10.2 Feedwater Stratif. cation.

l (1) Purpose The purpose of the feedwater stratification test is to confirm the vertical l

temperature gradients that can occur in the feedwater alping, eiti r inside or outside contamment, during certain operational modes c.o not, when combined l

with thermal expansion, produce pipe stresses, pipe movements or RPV nozzle loads in excess of design allowables.

(2) Prerequisites The preoperational tests have been completed and plant management has reviewed the test procedures and has approved the initiation of testing. For each scheduled testing iteration the plant shall be in the appropriate operational configuration with the specified prerequisite testing complete. The applicable instrumentation shall be checked or calibrated as is appropriate.

l l

Satisfactory completion of the thermal expansion test is a prerequisite to the stratification test. This insures the piping is free of obstruction that could constrain free pipe movement.

(3) Description The feedwater piping stratification test consists of measuring displacement, tem eratures and strains of the feedwater piping during these two operating m o' eS:

(a) During plant startup when hot RWCU is added to the cold feedwater line. The hot RWCU flows on top of the colder water ii; the feedwater line and does not mix with the colder water until mixing of the two stream occurs at the outer swing check isolation valve. Stratification for this condition can thus effect only the feedwater piping outside containment.

(b) The plant is in hot standby condition following scram. After scram, the temperature of the entire feedwater line is hot. When cold water is introduced to make up for decay heat boiloffin the RPV, the colder water flows along the bottom of the large diameter horizontal feedwater pipJ at low flow rate, creating stratification. The temperature difference between top and bottom of the pipe will decrease along the pipe in the direction of flow,-but stratification could still exist in the feedwater piping inside containment since the swing check valves are not effective in mixing the cold water flowing along the bottom of the pipe.

The test consist of measurement of (a) temperature around the circumference of the feedwater pipe at various locations inside and outside containment, (b) strains at points of highest stress inside containment, and (c) measurement of pipe displacements and movements inside and outside containment due to pipe bowmg because of stratification.

(4) Criteria Acceptance criteria are established for temperature measurements around the circumference of the pipe and for the strain measuremerts at the high stress points in the piping. Acceptance criteria is not arovided for the displacement measurements because of the uncertainities invo'ved with interpreting the test data which include displacements caused by both thermal expansion and stratification.

The acceptance criteria for temperature are based on the measured values not exceeding, actual values used for design and maximum values allowed without-overstressmg the feedwater pipe. The acceptance criteria for strains are based on the measured strains due to thermal expansion plus stratification'not exceeding strains predicted by saalysis and the maximum strains allowed by Code. The locations to be monitored and the aacceptance criteria for temperatur s and strains for the monitored locations in each plant will be provided by the applicable design or testing specification.

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NWAS Standardflant yl

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tion at various plant operating conditions in 14.2.12.2.10.1 System Thermal Expansion order to validate design assumptions and iden-tify any operational lirnitations that may (1) Purpose exist.

The purpose of the thermal expansion test is (2) Prereqmsites to confirm that tbc pipe suspension system The applicable preoperational testing has is working as desicned and tre pipeing is free of obstructions that could constrain been completed and plant management bas re-newed the test procedure (s) and has approved free pipe movement caused by thermal expansion.

the initiation of testing. For each sche-duled testing iteration the plant shall be in (2) Prerequisites the appropriate operational configuration with all specified prerequisite testing The preoperational tests have been comple:ed complete.

and plant management has reviewed the test procedures and has approved the initiation (3) Descripuon of testing. For each scheduled testing Dunng plant bestup and power ascension pert-iteration the plant shall be in the appro-priate operational configuration with tne inent parameters such as reactor coolant tem-specified prerequisite testing complete.

perature, vessel dome pressure, vessel water The applicaHe instrumentation shall oc level, and core flow will be monitored at se-checked or calibrated as is appropriate, lected intervals and plant conditions. This data will be used to verify proper instrument (3) Description response to changing plant conditions and to document the relationships amongst these pa-The therrnal expansion tests consist of rameters and with other important parvueters such as reactor power, feedwater flow and measunng displacements and temperatures cf piping during various operating modes. The stearn flow. The data will also be used to first power level used to verify expansion validate design assumptions such as those sball be as low as practicable. Thermai used in the calibration of vessel level or movement and temperature measurements shall core flow indication. Additionally, the data be recorded at at least the following test will be used to help identify potential points (followinc a suitable bold period te operational condition limitations such as assure steady state temperatures);

excessive coolant temperature stratification in the vessel bottom head region.

(a) during reactor pressure vessel beatup at at least one intermediate temperature (4) Cnteria prior to reaching normal operating temperature, including an inspection of The various nuclear boiler process instrumen-the piping and its suspension for ration shall operate as designed in response obstructions or inoperable supports; te changes in plant conditions. The observed process characteristics shall be conservative (b) following reactor pressure vessel beat relative to applicable safety analysis up to normal operating temperature; assumptions and-should be consistent with design expectations.

(c) following beatup of other piping syste=s 14.2,12.2.10 System Thermal Expansion and to normal operating temperature (those Feedwater Stratification.

s em whose bestup cycles differ from (2) above); and Tbc movement of piping systems due to thermal expansion and fluid temperature stratification is (d) on subsequent beatup/cooldow1: cycles, as monitored during the start up test program. The specifhd, at the apphcable operating thermal expansion test program applies to those piping and sbutdown temperatures, to measure systems identified in Paragraph 14.2.12.2.10.1 (3). The p ssible sbatedown effects.

fluid te nperature stratification test applies only to the

(

feedwater piping.

m.30 u

Standard Plant m.,

c.

I Thermal expansion shall be conducted on (2) Prerequisites plant systems of the following classifi-c tions:

The preoperational tests have been completed and (a) ASNE Code Class 1,0, and 3 systems; plant management has reviewed the test procedures and has approved the initiation of (b) high energy piping systems inside testing. For each schaduled testing iteration the 5::stnic Category I structures; plant shall be in the appropriate operational configuration with the specified prerequisite (c) high energy portions of syst:=s whose testing comple-The applicable instrumentation failure could teduce the functioning of shall be chec) or calibrated as is appropriate, any Seismic Category I plant features to an unacceptable level; and Satisfactory,ompletion of the thermal expansion test is a prerequisite to the stratification test. This insures the piping is free of obtruction that could (d) S::smic Category I portions of moderate e nstrain free pipe movement.

j energy piping syste:ns located outside Containment.

(3) Description (4) Critena The feedwater piping stratification test consists of measuring displacement, temperatures and strains

,he th:r=al expansion acc:ptance criteria are of the feedwater piping during these two operating i

based upon the actual movements being withm modes; a pres:ribed tolerance of the movements pre-dict:d by analysis. Measured movements at:

(a) During plant startup when hot RWCU is not expected to precisely correspond with added to the cold feedwater line. The hot those =athernatically predicted. Th:retore, a RWCU flows on top of the colder water in toleranc: is specified for differences bet-the feedwater line and does not mix with the we:n =:asured and predicted movement. The colder water until mixing of the two stream j

I toleranc:s are based on consideratton of occurs at the outer swing check isolation g

measur:=ent accuracy, suspension free play, valve. Stratification for this condition can thus and piping temperature distribuuons, if the effect only the feedwater piping outside

=:asur:d :novement does not vary from the pre-containment.

l dictions by more than the specified tole-ranc:. the piping is expanding in a manner (b) The plant is in hot standby condition consist:nt with predictions and is therefore following scram. After scram, the ace:ptable, Tolerances should be the same temperature of the entire feedwater line is for all operating test conditions. The loca-hot. When cold water is introduced to make tions to be toonitored and the predicted dis.

up for decay heat boiloff in the RPV, the place =:sts for the monitored locations in colder water flows ulong the bottom of the each plant will be provided by the applicable large diameter horizontal feedwater pipe at low flow rate, creating stratification. The

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{

142.122.102 Feedwater Stratification.

tercperature difference between top and bottom of the pipe will decrease along the g7 (1) Purpose pipe in the direction of flaw, but stratification A

could still exist in the feedwater piping inside The purpose of the feedwater stratification test is containment ;ince the swe.g check valves are to cottfirm the sertical temperature gradients that not effective in mixing the cold water flowing can occur in the feedwater piping, either inside or along tne bottom of the pipe, outsid: containment, during certain operational

{

mod:s do not, when combined with theimal t

expansion, produce pipe stresses, pipe tnovernents or RPV nozzle loads in excess of design L

allowables.

Amendmem :t I C $1

MN

'3A6100AN Standard Plant prv 9 4

(2) Prerequisites l

The test consist of measurement of (a) temperature around the circumference of the

he applicable preoperational phase testing feedwater pipe at various locations inside and is complete and plant management has reviewe5 outside containment, (b) strains at points of the test procedure (s) and has approved the highest stress inside containroent, and (c) initiation of testing. For each scheduled measurement of pipe displacements and test iteration the plant shall be in the ap-movements inside and outside containment due to propriate operational configuration with all pipe bowing because of stratification.

specified prerequisite testing complete.

The required remote monitoring instrumen-(4) Criteria ration shall be calibrated and operational.

I Acceptance criteria are established for (3) Desenption temperature taeasurements around the circumference of the pipe and for the strain Vibration testing duri.:g the power ascensice measurements at the high stress points in the phase will be litnited to those systems that piping. Acceptance criteria is not provided for the cou'd not be adequately tested during the displacement measurements because of the preoperational phase. Systems within the uncertainities involved with interpreting the test scope of this testing are therefore the same data which include displacements caused by both as mentioned in Subsection 14.2.12.1.$ 1.

thermal expansion and stratification. The However, the systems that remain to be accertance criteria for temperature are based on tested will primt ily be those exposed to the measured values not exceeding actual values and affected by steam flow and hich rates of used for design and maximum values allowed core flow. Due to the potentially high le-without overstressing the feedwater pipe. The vels of radiation present during power acceptance criteria for.; trains are based on the operation, the testing will be performed measured strains due to thermal expansion plus using remote monitoring instru=entation.

stratification not exceeding strains predicted by i

Displacernent, accele ition, and strain data

/

analysis and the maximum strains allowed by will be collected at various critical steadv Code. The locations to be monitored and the state operating conditions and during signiS aacceptance criteria for temperatures and strains Mem suc'n u turbine or eenm-for the monitored locations in each plant will be provided by the applimble design or testing tor trip, main steamline isolation. SRV ret-

$ P# " "'

uation and RIP trip (if not already per.

i formed). Steady state and transient vibra-

[

gg tion affecting the RCIC steamline will also u

be monitored.

(4) Criteria Criteria will be calculated for those points monitored for vibration for both steady if state and transient cases. Two levels of p

criteria will be generated, one level for predicted vibration and one level based on

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acceptable values of displacement and accel-L _ __ -

eration and the associated stress to assure 14.:.12.2.11 System Vibration that there will be no failures from fatigue over the life of the plant. Failures to (1) Parpose remain within the predicted levels of vibra-tion should be investigated but do not neces-To verify that the vibration of critical sarily-preclude the continuation of further plant system cotuponents and piping is within t e sting. However, failure to meet the acceptable liciits during normal steady state criteria based on stress h,mits will require immediate investigation and resolution while power operation and during' expected operational transients.

the plant or affected system is placed in a Am Mmen::t safe condition.

14.24th