ML20212D001
| ML20212D001 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 07/15/1997 |
| From: | John Lane, Miskiewicz D FLORIDA POWER CORP. |
| To: | |
| Shared Package | |
| ML20212C970 | List: |
| References | |
| F-97-0003, F-97-0003-R02, F-97-3, F-97-3-R2, TAC-M99277, NUDOCS 9710300237 | |
| Download: ML20212D001 (26) | |
Text
U. S. Nuclear Regul: tory Commission LTOPS TSCRN 213, Revision 1 3F109712 FLORIDA POWER CORPORATION CRYSTAL RIVER UNIT 3 DOCKET NUMilER 50 302/ LICENSE NUMBER DPR-72 TECIINICAL SPECIFICATION CIIANGE REQUEST NOTICE 213, REVISION 1 (TAC No. M99277)
ATTACIIMENT B CR-315 EFPY LTOP LIMITS FPC CALCULATION FP97-0003
[No Revisions have been made to this Attachment B since TSCRN 213, Revision 0]
DR D
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' Florida INTEROFFICE CORRESPONDENCE
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Nucl:ar Engineering
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SUBJECT:
Crystal River Unit 3 Quality Document Transmittal. Analysis / Calculation To. Records Management NR2A The following analysis / calculation package is submitted as the QA Record copy:
DOCN0 (FPc DOCUMENT IDEMrlFICATION NUMBER)
REV SYSTE W $1 TOTAL PAGES TRANbMffTED 4*-9'?-0003 1
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/ *7 fffLE C23 If GPPY t top u MirS KWDS (IDENTIFY KEYWORDS FOR LATER RETRIEVAL)
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DKREF (REFERENCES OR FILES UST PRIMARY FILE FIRST)
VEND (VENDOR NAME) l VENDOR DOCUMENT NUMBER (DKP3F)
SUPERSEDED DOCUMENTS (D AREF)
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l 22 12 G L l25-02.
I'-91-0003 rev I
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NOTE:
Use Tag number only for valid tag numbers (i.e., RCV 8, SWV.34, DCH 99), otherwise: use Part number field (i.e., CSC14599, AC1459). If more space is required, write "See Attachment" and list on separate sheet.
DE $lGN ENGINEER DATI WRIFICATION ENGINEER DATE SUPERVISOR. NUCLEAR ENG DATE OM
- 7 7
/Ud M/ME
/
cc: Nuclear Projects (if M CG EERE Calculation Revew form Part til sedons requeed M Yes O No Retum to Semce Related)
Yes b No (if Yes, send copy of the form to Nuclear Regulatory Assurance and a copy of Supervisor, Config. Mgt. Info.
the Calculation to the Responsible Organtration(s) identified in Part lit on the 1
Mgr., Nuci Operations Eng. (Onginal) w/ attach Calculation Revew form.)
S, 8: loll-Aev 191
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CALCULATION REVIEW CALC AEV FPN Page 1 of 2 cucuanonomev F-17-OO O 3 t ev. 2.
PARTl.
DESIO:' ASSUMPTION / INPUT REVIEW: APPUCABLE 6 Yes O No The following organizations have reviewed and concur with the design assumptions and inDuts identified
'or this calculation:
Nuclear Plant Technical Support bante, b. E 7 f/6 77 System Engr p**'
Nuclear Plant Operations 7/8/87 oTHER(s) 37"**
/d OutLWAtt
$ YtMtt0G.
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PART 11 RESULTS REVIEW: APPLICABLE E Y.s O No The following organizations have reviewed and coneyr with the results of this calculation anj understand the actions which the organizations must take to implement the results.
9 Nuclear Plant Technical Support System
- f. lh 7//5Y17 Engr 6f"*'**
Nuclear Plant Operations
/[/7) s.usu v
Nuclear Plant Maintenance
~
' ' ~ * " *
- 0-Yes N/A Nuclear Ucensed Operator Training O Yes E N/A Manager Site Nuclear Services Sr. Radiation Protection Engineer
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Yes E N/A ll" h a _ a C A.d,s./n Wuweb Wee W
CALCULATION REVIEW cucuweenev.
Athoco3 m.
2.
PART 111. CONFIGURATION CONTROL: APPLICABLE Q Yes No The following is a list of Plant procedures / lesson plans /other documents and Nuclear Engineering calculations which require updating based on calculation results review:
Document Date Reauired R
isible Oroanization Z'ti 0005 bd If, /tti
_A)ne. h e f oneerra Q D, man ha'n.s
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N Upon completion, forward a copy to the Manager, Nuclear Regulatory Assurance Group for traciting of actions if any items are identified in Part lit.
PART IV
-- NUCLEAR ENGINEERING DOCUMENTATION REVIEW The responsible Design Engineer me thorougNy review the below lbted documents to assess if the calculation requires revision to these documents, if "Yes," the change authorizations must be listed below and issued concurrently with the calculation.
Enhanced Desqpn Bee. Document E Yes O No nCa 6N Vendor QuehRoshon Package O Yes % No 8*a -
FSAR S Yes O No h*aNel410113 Topad Desspo Bases Doc.-
OYesSNofrCe imprwed Tech. Specshcomon E Yes O No hwa15CA#til E/SQPM O Yes E No (TC*
Imptwed Tech. Spec. Bese.
5 Yo. O No h*a 73Qr# 2,13 'Other Documents rewowed.
1 Cona. upmt. wo. syeesm -
E Ye. O No scic*agiocreof O Yo. O No s
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Ana8ynas Bees Document O Yes E No fica O Yes O No D gn Be Docum.ni O Ya E No nca O Y. O No
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Appendet R Fue Study 0 Yu E No nCa L Yu O No Fwe Hazardous Analy O Yes E No nea' O Yo. O No
~ ~ ~
NFPA Code Conformenos Documere O Yes @ No fica O Y.s O No sewes occ namocei PART V - PLANT REVIEWS / APPROVALS FOR INSTRUMENT SETPOINT CHANGE PRC/DNPO approval is required if a setpoint is to be physically changed in the plant through the NEP 213 process.
. PRC Review Required Yes
@ No PRC Chawmen
/Date
. DNPO Review Required Yes b No DNPO
/Date ocse o c=::mit cesov emeen.mento eame 0, b. N 5 42 O N. Ml$k!IfWIC 1 y
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CALCULATIONAL
SUMMARY
SHEET (CSS)
I i." M t ? ?. M l
DOCUntrKTIDFMTrFrER tt_tsut9tas TrTLE CR-315 EFPY LTOP Linilts I
PREFARED BYI REVIEMID BY:
NAA*3 J. A.Weimer NAhfE BL Boman SIGNATURE
$1CNA1 L'RE A
Wh MLE
[j9 - [g; f,g g hgp 7[g/py
%A7 DATE m Sw.wa.~ cm.
DATE gg PIF. FACE (S) 3 Thl STATEht'ENT: REVIEMIR INDEFENDENCE COST CENTER FURPOSE AND
SUMMARY
OFllESULTS:
PURPOSE The purpose of the calcul.vions provided herein are to:
(1)
Derme the 15 ETY enable temperature.
(2)
Determine the location adjusted 15 EFPY LTOP PT limit and show that the current PORV setpoint protects this limit.
(3)
Derme a maximum allowable, instnament corrected, pressurizer level for Crystal River 3 such that the most limiting LTOP event, failed-open makeup control valve, will not violate the 15 EFPY LTOP pressure-temperature limit.
(4)
Derme the makeup tank level for which a failed open makeup control valve will not violate the LTOP limit.
(5)
Provide all the appropriate assumptions and operation restrictions to implement these LTOP limits.
(6)
Show that the 0.75 in' RCS vent hole size is sufficient to mahitain the pressure below the LTOP PORV setpoint for a failed open MU control valve.
The results of this analysis are discussed on page 4.
THE FOLLOWING COMFtJTER CODES HAVE BEEN USED IN THIS DOCUMENT:
CODE / VERSION / REY CODE / VERSION / rey THIS DOCUME.Yr CONTAINS ASSUMPTION $ TitAT MUST BE VERIFIED FRIOR TO USE ON SATETY.RELATED WORK YES ( /) NO (
)
CR-3 N) T-97403 Rev. 02 PAGE 1
OF 14
20004B.S (3/97) as at OLO 8
NUMBER:
RECORD OF REVISION 3212es125 02 REV.NO.
CHANGE SECT / PARA.
TESCRIPTION/ CHANGE AUTHORIZATION 01 The entire Rev. O is Different initial assumptions required a complete replaced with Rev. 01 re-calculation 02 Reference List (pg. 3)
The date and revision level ofReference 12 was corrected 02
" Pressurizer level / initial Additions discussion was included to embellish pressurizer parameter" the pressurizer level section
]
section (pg,6) i i
DATE:
PAGE:
7/14/97 2 of 14 CR-3 No F-97-003 Rev. 02
rnox 331:660soa aw.
REFERENCES 1.
FTI Doc 77 209100 "FT Limits for 15 EFPY for CR 3", 8/89 2.
FTI Doc. 321176020 00 "CR 3 Corrected P/T Limits at 15 EFPY" 8/89 3.
FPC Calculation I 97 0005, "RC Low Range Pressum Loop Accuracy, RC 131.PT (LTOP Serpoint) Rev 0.
4.
FII Doc. 32 5000115-00 "CR-3 NPSH, Seal Staging, DHRS, subcooling, NDT Limits" 5.
FTI Doc 32-1259026-00, "CR 3 LTOP Setpoint for 15 EFPY' 3/97 6.
FTI Doc. 321176228-00 "LTOP Design Bases Analysis" 9/89 7.
- CR 3 Drawing 4CP.2433 8.
FTI Document 32-1259000 00, " Pre.Startup LTOP Set point", AD Nana, Manh 1997 9.
- FPC Calculation I 88 0021, Revision 2.
10.
FTI Doc 32 5000279-01 "CR-3 PORY and RCS Vent Flow" 6/97 11.
FTI Doc. 32-1268903-00 "CR 3 Partial Pump Flow & Pressure Dist. 7/97 12.
FTI Doc. 321266172-01 "CR-3 LTOP RELAP.5 Analysis" 6/97 13.
FTI Document 51-121232 01, " Key Elevations for All Plants", BR Aldefer Mach
- 1994, 14.
- FPC Calculation M94-0053, Revision 4.
15.
- FPC Calculation 1910002, Revision 0, "MU Tank Level Accuracy".
16.
- FPC Calculation I 95-0015, Revision 0, " Core Flood Tank Level & Pasore Loop Error Evaluation".
17.
" FPC Calculation M 97-0044 Revision 0.
These sa refennees controlled and retrievable tiuvugh FPC d ment control system and can be used as acceptable references for this document.
gl PURPOSE.....................................................................
.1 RECORD OF RE VIS ION.........................................................................
..............2 REFERENCES.............................................................................................
.3 RESULTS...............................................................................
...............4 LTOP LIMIT AND PORV SETPOINT....................
4 ND T C UR VES...........................................
.....4 MAXIMUM ALLOWABLE PRESSURIZER LEVEL.........................
.4 MU TANK VOLUME...................................,,
.5 LIMITING TEMPERATURE FOR CPT FLOW INITIATION................................. 5 KE Y INP UT AS S UMPTION S.....................................................................
.5 PRESSURIZER LEVEL / INITIAL PRESSURE PARAMETERIZATIONS
.........6 PORV and VENT FLOW RATES..........................
.6 AS S UMPTI O N S..................................................................................
........6 INSTRUMENT UNCERTAINTIES AND LOCATION CORRECTION....
..............7 CALCULATIONS.........................
...................7 P ORY S etpoint..............................................
.. 7 Maximum Allowable Pressurizer Level...........................
.9 F10URES.
. 10
.......................................... ~....... ~............ ~.. ~. ~.
CR.3 No T 97 003 nev. 0 Pap 3ofI4
FT! Doc. 331266125 02 J A Weimer l
3 RESULTS LTOP LIMITANU PORVSETPOINT i
l De minimum L'IUP allowable pressure a 464 psig as measured ftom the hot leg "A" i
tap per Figure 1. He base LTOP lhalting curve is defined in Reference 5 as 110% of the steady state HU/CD pressure limit as a function of temperature, ne adjusted LTOP limit at 85'F is 548 psig (Reference 5) minus the 2/0 location correction (84 l
.l psi).- Based on the current low range PORV setpoint of 442.6 psig and its pressure uncertainty of 11.4 pai, Reference 3, the maximum PORV opening pressure setpoint is l
454 psig. Dus, the LTOP limit is protected by the low-range PORV setpoint.
f f
His LTOP limit is applicable below the enable temperature of 263'F which is the I
RtNDT (203'F) + 50'F (required conservatism) + 10*F (instrument uncertainty).
l 1
1 Figure I shows the entire LTOP limit up to the 263'F limit.
i NDT CURVES
)
Figure 2 shows the present 15 EFPY heatup and cooldown curve assuming the original l
instrument uncertainties (25 psi,10*F). Also shown is the restricted operational ama due to the low-range PORV setpoint. His region of the operator curve is set to prevent challenging the PORV.
With the PORY setpoint of 442.6 psig and its i
pressure uncertainty of 11.4 pai, Reference 3, the minimum PORY opening pressure j
setpoint is 431.2 psis (rounded to 431 psig).
To provide an operating limit to preclude PORV challenge the Intilcatart uncertainty of 16 psi, Reference 3, is j
subtracted from the minimum PORY opening piessure setpoint of 431 psig, to yield i
415 psig as shown in Figum 2. - his PORV operating limit is incorporated into the I
other heatup and cooldown limits, Reference 4.
MAXIMUM ALLOWABLE PRESSURIZER LEVEL The raaximum allowable indicated pressure is based on the envelope of the heanip,
[
[
cooldown, and restricted ama shown in Figure 2.
If the RCS is at the maximum L
allowable indicated pressure, a pressurizer level of 160 inches (135 inches instrument corrected) will not allow the maximum RCS pressure to exceed the LTOP limiting curve for 10 minutes during a failed open makeup control valve event. Note that the initial conditions for the LTOP event are adjusted from the indicated conditions by the pressum and temperature uncertainty. For the NDT curves, a pressure uncertainty of i-16 psi was added (i.e., if the plant pressure was at the NDT limit, the actual pressure could be 16 psi greater). For the PORV operating limit of 415 psig, an additional 10 psi was added to the 16 psi instrument uncertainty due to the fact that the current PORV setpoint could be increased by approximately 10 psi and still protect the LTOP i
r i
CR 3 No F 97-003 Rev. 02 Page 4 of14
FT! Doc. J31266125 02 J A Weimer limit. Also, the !nitial conditions have 10'F subtracted from the NDT and PORV operating limit curves since the actual temperature could be 10*F less.
'Ihe actual RCS pressure aher 10 minutes of =nimum makeup for 150",160", and 190" (nitial pressurizer levels (compared whh the LTOP limit) is shown on Figure 3.
Figure 4 shows an enlargement of the critical temperature for the 160" initial pressurizer level.
MU TANK VOLUME If the MU tank volume depletes in less than 10 minutes, the pressurization transient will stop. The volume of water required to pressurize the RCS to the LTOP limit starting at 425 psig' is 27881 lb or 3342.2 gallons (Reference 12). 'Ihis is equivalent to 88.9 inches in the MU tank per the MU tank volume equation Vgal = 31.26 x (level in inches) +5u2 gal as described in Reference 6'.
Using a conservative makeup tank level uncertainty of approximately 3 inches (2.7" in Reference 35), this means that if the MU tank is less than 86 luches (indicated), the LTOP limiting curve cannot be reached during the 10-minute transient from initial pressures discussed above.
. LIMITING TEMPERATURE FOR CFTFLOWINITIATION The maximum calculated CFT pressure is 638 psig, Reference 16. If the CFTs are not isolated from the RCS, the LTOP limit can be protected by raising the RCS temperature above the value corresponding to an RCS pressure of 638 psig. For the 15 EFPY LTOP limit, Table 2, this temperature is 197'F, uncorrected. Correcting for the 10'F uncertainty provides a procedural limit of 207'F.
KEYINPUTASSUMPTIONS Other results pertinent to this analyses include the input assumption that no RC pumps can operated below art hidicated RCS temperature of 95'F (85'F uncorrected and 10 F uncertainty) and the third RC pump cannot be operating below 230*F (220'F uncorrected and 10*F imcertainty).
The LTOP 10-minute transient assumed the pressure location corrections assoelated with these pump combinations. While the maximum allowable pressurizer level and LTOP limit would accommodate fourth RC pump start above 235'F, core lift considerations would preclude fourth RC pump start below the LTOP enable temperature.
1 This is conservative relative to the 431 psig lowest PORV opemng pressure, 2 Note that Reference 17 shows a slightly different MU tank total volume equation.
CR 3 No F 97 003 Rev. 02 Page 5 of14
FT! Doc. 321266125-03 J A Weimer PRESSURIZER LEVEUNITIAL PRESSURE PARAMETERIZATIONS A higher initial pressurizer level can be tolemted if the initial pressure is less than the NDT ilmit discussed above. Calculations of the pressurization during the 10 minute failed open
==Wy control v:lve transient were conducted as a function ofinitial pressure and pressurizer level, Reference 12.
Using the LTOP limit as the maximum allowable pressure, the maximum allowable pressurizer level vs RCS pressure relationship was developed as shown in Figure 5. For example, if the indicated RCS pressure was 198 psig, the maximum allowable ind! ated pressurizer level would be 220 inches.
PORVand VENTFLOWRATES Reference 10 demonstrates the adequacy of a 0.75 in' RCS and the 1.049 in' PORV to provide sufficient flow to prevent RCS pressurization above the LTOP limit. De RCS vent -
conservatively provides a discharge of 345 spm at 431 psig (the lowest PORY opening pressure) and il temperature of 212'F versus the failed open makeup control valve flow rate of 340.5 gpm at the same RCS pressure. De PORV will provide a steam flow of 4.1 ft'/s at 431 psig which is far in excess of the failed open makeup control valve flow rate of 0.8 ft'/s.
In addition, values of PORV steam, liquid water, and nitrogen flow rates were calculated at the revised PORV setpoint of 442.6 psig. Thus, the revised Table 4-1 FSAR Values should be:
Iow Pressure Open Setpoint 442.6 psig
=
Low Pressure Closed Setpoint 392.6 psig
=
Design Capacity 14,180 lb./hr
=
Liquid Capacity @442.6 psig 505 gpm'(@l00'F)
=
160 spm (Satumted Liquid)
=
Nitrogen Capacity @442.6 psig 20,560 lb./hr
=
ASSUMPTIONS The results presented herein are based on the following assumptions and inputs:
(1) ne first reactor coolant pumps-will not be started until the monitored RCS temperature is greater than, or equal to, 95'F. Accounting for the DHRS temperature uncertainty of 10'F, the analyzed first reactor coolant pump temperature start is 85'F. De reactor coclant pump stut temperatures affects the hot leg pressure tap to reactor vessel beltline pressure differential correction (i.e., location adjustment)
(2)
The minimum allowable temperature for the third reacter coolant pump start will be 230*F (220'F analyzed and 10'F uncertainty).
CR 3 No F 97-003 Rev. 02 Pap 6 of14 s
a
FTI Doc. 38 1266125 03 J A Weimer (3)
The pressurizer pressurization rates are based on the makeup system configuration discussed in Reference 12. They are approxinsately 330 to 365 gpm at RCS pressures less than 500 psig.
~
INSTRUMENT UNCERTAINTIES' AND LOCATION CORRECTION Since this evaluation only applies to LTOP considerations (up to 263F and below 464 psig), the wide ange pressure uncertainty is not applicable and only low range pressure will be addressed. The 15 EFPY NDT curves used a 25 psi pressure uncertainty and a 10'F temperature uncenainty. Since these are conservative relative to more recent uncertainty calculations, they will not be changed.
The LTOP limit does not use an uncertainty explicitly but rather the indicated pressure uncertainty is added to the opcrator curve limits to form the starting point of the LTOP transients._ This analysis will use the 15.2 psilow range uncertainty (rounded to 16 psi) per Reference 3 and will be used for all pressure indications herein.
'Ihe decay heat outlet temperature uncertainty is 6.8 + 2.5 readability = 9.3 and the
)
RTD's are 8.3'F (see Reference 4). Therefore, since the 9.3 is bounded by the l
original 10'F uncertainty,10'F will be used for the LTOP work. Again, the LTOP l
limit does not incorporate this uncertainty directly but temperature uncertainty is subtmeted from the operator curve limits to form the starting point of the LTOP transients.
The pressurizer level uncertainty is -7.47% of span, Reference 9. From, Reference.13, the upper tap is at 52.03 ft and the lower tap is at 24.74 ft. This corresponds to
-0.0747'(52.03-24.74)* 12 = 24.5 inches (25" was used in the analysis).
The location pressure adjustments from the beltline to the hot leg taps during pump operation are based on Reference 11. During no pump operation, the location correction is effectively a stagnation head of 23 psi (Reference. 8). These location corrections are shown for the appropriate temperatures below.
CALCULATIONS PORVSetpoint The PORV setpoint for LTOP protection must be at the minimum LTOP pressure. This minimum pressure is determined from the Reference 5 pressures (see Table 2 below) wid:
location correction and instrument uncertainty added. The Reference 5 allowable pressures are a composite of the minimum pressure at the belt line, CL nozzle, or closure head (as a 3 'Ibe original vocertamty was 25 psi and 10*F for the entire PT range.
CR 3 No F 97 003 Rev. 02 Page 7 of14
DiMLh3 98 MtbMM2
- 3w function of temperature). Dese pressures are 110% of the steady state heatup/cooldown limit.
ne Reference 5 pressures (shown in Table 2 below) continually increase with temperature, ne location adjustment to the "A" and "B" bot legs, however, are a function of the number of RC pumps operating, Reference 11. Since tLt number of operating pumps is the key component of the location adjustment, pump operating restrictions must be set to assure a reasonable LTOP minimum pressure. Typical location adjustments are 80100 psi for 2 or 3 j
pump operation and 23 psl for zero pump. operation, Reference 8. Since the combination of the surge line limit and the seal staging limit, Reference 4, prevents RC pump operation below 95'F, this will be chosen as the minimum temperature for RC pump operation, ne actual pump start wa.t assumed at 85'F to account for temperature uncertainty.
Figure 1 shows the minimum LTOP setpoint limit for CR 3 to be 464 psig at 85'F. The 0/2 pamp combination will have a smaller location correction and therefore the 2/0 case is conservative for all startup cases.
Table 2 Reference 5 LTOP plus Adjustments name LTop oc l
2e l
W2 l
2n Press Mme iM 88 LoCArlON CORRECTION P. psi 9 T.*F Psid Paid Psid Paid psi 9 525-70 23 85.00 32.74 10~t.00 502.00 545 80 23 84.00 32.68 102.00 522.00 548 85 22 84.00 32.66 102.00 525.00 548 85 23 84.00 32.66 102.00 464.00 551 90 23 44.00 L2.64 102.00 467.00 558 100 23 84.00 32.60 101.00 474.00 567 110 23 44.00 32.55 101.00 483.00 575 120 23 84.00 32.49 101.00 491.00 581-125 23 84.00 32.46 101.00 497.00 814 150 23 83.00 32.30 100.00 531.00 061 175 23 83.00 32.10 100.00 578.00 688 195 23
_, 82.00 31.92 99.00 606.00 728 200 23 62.00 31.87 99.00 646.00 775 121 23 82.00 31.75 99.00 693.00 808 220 23 82.00 31.67 98.00 725.00 808 220 23 82.00 31.67 98.00 709.00
__ 825 225 23 81.00 31.61 98.00 727.00
~
849 230 23 -
81.00 31.56 98.00 751.00 96c 250 23 81.00 -
31.32 97.00 867.00 98.
253 23 81.00 31.28 97.00 888.00 Alllos Jon adjustments are rounded up to the next highest whole number.
CR 3 No F 97 003 Rev. 02 Page8of14
FT! Doc. 331266125 02 J A Weimer The RCS pressure must not exceed this pressure (464 psig) until the RCS temperature is greater than the RtNDT plus 50'F conservatism plus the temperature uncertainty (10'F). This is 263'P. Therefore, during a heatup or cooldown, the RCS cannot exceed 464 psig until the RCS is greater than 263'F indicated. Figure 2 shows where this limit is lower (more conservative) than the NDT heatup and cooldown limits.
Maximum Allowable Pressurizer Level The maximum allowable pressurizer level was calculated by first determining the maximum allowable pressure increase (during the 10 minute MU transient). The initial RCS pressure
>ss assumed to be the maximum allowable operating pressure.1his value was either: (1) the NDT heatup or cooldown limit with 16 psi added for the indicated pressure uncertainty, or (2) the 415 psi PORV operating limit with 16 psi added for the indicated pressure uncertainty and i
10 psi for the PORV setpoint margin (i.e., the current setpoint could be increased by
_ approximately 10 psi and still protect the LTOP limit). Prior to reaching the PORV operating limit, the cooldown NDT limit is more restrictive than the heatup limit except for a small region between ~210 and 230*F (see Figure 2). Beyond the LTOP enable temperature (263*F), the heatup NDT is the limiting curve.
l l
Starting from the minimum enveloping curve on Figure 2, the 10 minute MU transient
_ pressure was added to the initial pressure assuming a 150" and 190" initial pressurizer level.
This added pressure was based on Reference 12. A simple linear equation was developed describing the 10 minute pressurization rate. This was:
Final Pressure = 0.833* Initial Preuure - 41.6 for 190" initial pressurizer level and Final Pressure = 0.666* Initial Preuvre - 58 for 150" initlal pressurizer level Figure 3 shows these results. The 190" case exceeded the LTOP limit at approximately 180F, The 150" case was below the LTOP limit for the entire temperature range. The 160" case (interpolated from 150" and 190") will approach the LTOP limit at 195'F. Note that the 2/0 pump combination was assumed for the pressure location correction until 230*F. Figure 4 shows an enlargement of the critical temperature for the 160" initial pressurizer level. - This figure shows that there is approximately 10 psi additional margin to the LTOP limit at the present PORV setpoint.
CR 3 No F.97 003 Rev.02 Page 9 of14
FTl Doc. 32-1266125-02 FIGURE 1 CR-3 15 EFPY LTOP LIMIT I
1100' i
1050
- f[
1000
-*--LTOP Limit at Hot Leg w/ Loc Adsstments 950
- -110% Steady State LTOP Limit
/\\
$ 900
=* Minitr=Jm Allowable LTOP Limit (464 psig) j E 850 f
E
- s 800
/
750
/
/
700
-?
' /
a 650 e-S 7
p
/
600 550 500 d w_
i 400 i
350 f
300 50 100 150 200 250 300 RCS Temperature (F)
CR-3 No F-97-003 Rev. 02 PAGE 10 of 14
FTl Dt-:. 32-1266125-02 FIGURE 2 15 EFPY NDT COOLDOWN & HEATUP LIMITS 8"
i i
750 1
700 i.
15 EFPY Cooldown Limit
[
g 650
--e-LTOP Restrided Area (415 psig)
E 600 P.
- - - 15 EFPY Heatup Limit y 550
,/ ""
I c
[500
/,'
e
< 430
[ *'
=
x I
E J
i
/
350 U) 7
=
300
~~
j 250 200 150 I
50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 223 240 250 260 270 RCS Temperature (F)
CR-3 No F-07-003 Rev. 02 PAGE 11 of 14
FTl Doc. 32-1266125-02 FIGURE 3 15 EFPY LTOP 10 MIN MU TRANSIENT PRESSURE INCREASE 900 f
800
--e-Minimum of 15 EFPY Cooldown/Hestup
--e-10 MIN Transient Pressure (150 in. Pn Level)
[
--*--Hot Leg Corrected LTOP Pressure Limit iFM
~ 700 o
/
{
- - - 10 MIN Transient Pressure (160 in. Pn Level) g i
E
--o-10 MIN Transient Pressure (190 in. Pzr Level) -
/
r U
y e
" 600 l'
d I
a 7
a f' y
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1 f500 v
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O 300 w--
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200 100 50 60 70 80 90 100 110 120 130 140 150 130 170 180 190 200 210 72 230 240 250 260 270 RCS Temperature (F)-
t CR-3 No F-97-003 Rev. 02 PAGE 12 of 14
. ~...
t 32-1266.25-02 FIGURE 4 15 EFPY LTOP 10 MIN MU TRANSIENT PRESSURE INCREASE 750
~
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y f
c '
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o g-Min 15 EFPY HUrr Plus PORV Set Poird to 500
-e-10 MIN Transient Pressure (150 in. Pn Level) 0
-*-Ho Leg Corrected LTOP Pressure Limit
- - - 10 MIN Transient Pressure (160 in. Pzr Level) 450 400 190 195 200 205 210 215 220 225 230 235 240 245 250 RCS Temperature (F)
CR-3 No F-97-003 Rev. 02 PAGE 13 of 14
s s
FIGURE 5 Maximum Allowable Pressurizer Level vs. RCS Pressure i
260
_ _ __ __. _ (214 psig, 24s in.)
Instrument Corrected 240 -----------------------3y-------------
16-psig, -25_ inches -
y g
Uncorrected o 220
V-----------
.C
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(198 psig,220 in.)
\\
1 O
> 200
--- l----------------------------
O
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O 180 - - - - - - - - - - - - - - - - - - - - - - - - - -
. _N.
\\
i
'3
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m (286 psig,160 in.)
\\
m 160 - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
O uk
^
i i
i 140 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
ca (270 psig,135 in.)
M w
m t
120 I
I I
I a
0 100 200 300 400 500 m
i Pressure, ps.ig
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i CR-3 No F-97-003 Rev. 02 Page 14 of 14 4
U. S. Nuclear Regulator) Commission 3F109712 - Response to NRC RAI(LTOPS)
ENCLOSURE 1 FLORIDA POWER CORPORATION CRYSTAL RIVER UNIT 3 DOCKET NUMBER 50-302/ LICENSE NUMBER DPR-72 RESPONSE TO NRC RAI LTOPS TSCRN 213 (TAC No. M99277)
U. S. Nuclear R:gulatory Commission 3F109712 - Response to NRC RAI(LTOPS)
NRC REQUEST NUMBER 1 By leser deed August 12,1997 and subsequest telephone convenations with your maff, we requeskxl the t!e L10P limiWyalues listed in the prtposed TS be adpsed for innrument uncertairnies. By leaer d.ded Septenher 5,1997, you perwided a rayonne to our request. You inviM that the applicable inananent uncertainties will be accourned for in he (penting pmcedures rather than in the TS. You stated that this would allow revisions to setpnints in prtxalurcs due to any instmment modifications and the your position is commiert with other setpoints in the CR3 TS. We do rut conar with ycnu position. We have determined that the values for the pawer <perated relief valve (PORV) liA seapoint, pressurizer level and L10P enshie kunpermure values specified in the TS should be consisket with the nutixxiology druihed in the TS Bases -3.3.1. - (epage B 3.3-10) for the R=*r Pronextion System and should be consenatively majusted for inammer.t uneenainties. Accontingly, please submit a revised license amendmert request.
FPC RESPONSEt
. The values for the PORV lift setpoint, Pressurizer level, and LTOP' enable temperature specified in the new proposed ITS Section 3.4.11, LTOPS, have been corrected to be-consistant with the me$odology described in the ITS Bases 3.3.1 for the Reactor Protection System as required by the NRC.
Thesc values -have been conservatively adjusted for instrument uncertainties and are included with FPC's revised license amendment request, LTOPS TSCRN 213, Revision 1.
U. S. Nucl:ar Regul: tory Commission 3F109712
, - Response to NRC RAI(LTOPS)
NRC REQUEST NUMBER 2 l
We also r-~% in our August 12,1997 RAI, that the ternperature difference between the reactor coolar l
and the vessel metal at a distance ordfounh of the vessel wall thickness from the inskle surface (i.,
l l
quaner-t location) shouki be accounted into thehd..,, don of the L'IUP enable temperature as is sr.ded
?
in the ASME Code Case N 514. Your September 5,1997 leuer indicated that your LTOP analysis is based on steady state or isothermal conditions and considered the quaner-t metal ternperature to be equal to I
the water temperature. His is not consistent with the ASME Code Case N-514 and the NRC Branch l
l Technical Position 5.2.2.. Derefore, please account for the quaner-t ternperature difference due to j
temperature gradient across the reactor vessel wall.
k FPC RESPONSE:
- ASME Code Case N 514 defines the LTOP enable temperature to be RTwr + 50 deg for the limiting material. This is 253'F for Crystal River 3 (CR-3) based on the 15 EFPY data. A
. note in N 514 specifies that this should be the temperature at 1/4T from the inside surface of the vessel wall. The analyses performed to determine the limits for Low Temperature Overpressure Protection (LTOP) are based on an assumotion that LTOP events are most likely i_
. to occur when the reactor is at steady state conditions. 2 als assumption has been expanded in the CR-3 analysis and at other plants to mean that the reactor vessel is at isothermal conditions 3
or that the temperature is constant through the thicknew of the vessel wall. Using an
- isothermal assumption, the temperature at the vessel 1/4T location would be the same..s at the 1
inside surface of the vessel which is exposed to the water. Ir uctuality there is some heat loss through the vessel wall and the insulation, and there would be some temperature gradient i
- through the wall. In addition, heatup and cooldown operations would add additional-
. temperature differences between the quarter-t vessel location and the water.
.f The reactor coolant temper,eture that is measured for LTOP is the water temperature entering the reactor vessel since this is the coolest temperature to which the vessel will be exposed.
During cooldown -oprations, the quarter-t vessel temperature is higher than the water temperature and monitoring the water temperature is conservative. During heatup operations, i
monitoring the water temperature is non-conservative, and during steady-state conditions where the RCS heatup has been suspended for a period of at least 90 minutes, the quarter-t vessel temperature has been determined to be within 1 degree of the water temperature. This 4
steady state gradient has been evaluated using Newton's Law of Cooling and Fourier's Law,
.A minimum water temperature of 254*F was used since the LTOP controls can not be exited l
until the temperature is greater than 253 'F ( not corrected for instrument uncertainty).
t Based on this evaluation, the temperature difference between the reactor coolant and the vessel 1/4T location is less than l'F. Steps'will be included in the plant heattip proct :ure to require a
- reactor coolant system heatup holding period of 90 minutes after the enable temperature has been exceeded and prior to exiting the LTOP LCO. Therefore, the LTOP enable temperature 2
limit of s 253'F (not corrected for instrument uncertainty) based on the water temperature is acceptable for use since the reactor vessel will be at steady state conditions and the vessel 1/4T 3.
location temperature will be above the enable temperature.
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U. S. Nuclear Regulatory Commission -
3F1097-12 - Response to NRC RAI(LTOPS)
NRC REOUEST NUMBER 3 Please describe the operator actions to tenninate an LTPP ewnt within 10 minutes.
EEC RESPONSEt The limits for LTOP were developed to provide the operators with at least 10 minutes to respond ta and tenninate an LTOP event before the limits are exce td. The most limiting transient for LTOP is makeup injection through a stuck full open makeup valve. During this transient the makeup flow is approximately 340 gpm, and the MAKEUP FLOW 111G11 alarm (160 gpm) would provide immediate indication of a potential LTOP event. Alarm response procedure, AR-403, directs the operators to observe LTOP concerns and refers to operating procedure OP-301, Operation of Reactor Coolant System (RCS), for action required.
If Pressurizer level or RCS pressure temperature limits confirm a LTOP event, the operators will immediately stop the operating makeup pump and take additional actions as r.ecessary.
For potential LTOP events due to makeup flows less than 160 gpm, other alanns and indications, although not specifically installed for LTOP, would be available which would alert l
the operators to take action. The most obvious indication would be alarms associated with the Automatic Closure Interface System (ACI). This system is used to protect the Decay lleat System from overpressure, and is typically in operation at RCS pressures less than 284 psig and temperatures less than 280 degF.
There are alarms which will indicate a potential pressurization.nent at 200 psig and at 284 psig. Alarm response procedure, AR 303, instructs the operator to investigam the cause of increasing pressure in the RCS. If this were a potential LTOP event, the operator would have about 20 minutes to diagnose and termim te the event by stopping the operating makeup pump.
If the makeup flow is less than 160 gpm and the ACI system is not active, other alarms would actuate to alert the operators to a potential overpressure event.
These alarms include Pressurizer level alarms at 200 inches and 240 inches (AR-501). At the time when the 200 inch alann actuates, the operator would have more than 18.5 minutes to diagnose and terminate the event. Additional alarms include the Makeup Tank low level alarms at 55 inches and 18 inches (AR-403), and the RCS lilGH PRESSURE AT LOW TEMPERATURE alarm (AR-
$01) at 50 psig below the PORV setpoint. Operators would have more than 15.7 minutes from the 55 inch alarm to mitigate the event, and more than 9.8 minutes from the RCS HIGH PRESSURE AT LOW TEMPERATURE alarm.
The following table lists the various alarms and the estimated timing assuming a conservative makeup flow of 160 gpm. The table also assumes that 'he initial levels in the Pressurizer and the Makeup Tank are at the most limiting conditions of 160 inches and 100 inches,
- respectively.
e
U. S. Nuclear Regulatory Commission 3F109712 - Response to NRC RAI(LTOPS)
Alarms Time to Alarm Time to Limit (min)
(min)
MU flow high 160 gpm NA PZR low level (clear) 200in 6.0 18.5 MUT low level 55in 8.8 15.7 PZR level high 240in 12.0 12.5 RCS Press high 392.6 psig 14.7 9.8 PZR Level high high 275in 17.3 7.3 PORV open setpoint 442.6 psig 21.6 2.9 LTOP Limit @ Gb degF 464 psig 24.5 0.0 At higher RCS temperatures, the LTOP limits are greater than 464 psig, and more than 10 minutes would be available for operator response from the actuation of the RCS lilGli PRESSURE AT LOW TEMPERATURE alarm.
Given the availability and diversity of alarms which would alert the operators, and the i
relatively simple actions required to mitigate the event, there is a very good probability that the l
operators would be able to prevent an event from exceeding the LTOP limits.
1 g
i y---,
U. S. Nuclear Regulatory Commission 3F1097-12 En-losure 1 - Response to NRC RAI(LTOPS)
ENCLOS'URE 1 FLORIDA ??OWER CORPORATION CRYSTAL RIVER UNIT 3 DOCKET NUMBER 50-302/ LICENSE NUMBER DPR-72 RESPONSE TO NRC RAI LTOPS TSCRN 213 (TAC No. M99277) n
L. S. Nuclear Regulatory Commission 3P1097-12 - Response to NRC RAI(LTOPS) 4
?)wb; NRC REQUEST NUMBER 1 By letter dated August 12, A7 and subsequent teleplene conversations wth your staff, we requested that de
[
L'IDP limits / values listed in the proposed TS be aljusted for instrument uncertainties. By letter datext September 5,1997, you pmvided a imense to our request. You inlicated that the applicable instrumert uncertainties will be accourted for in the operating pmcedures rather than in de TS. You stated that this would allow revisions to setpoints in procedures due to any instmment modifications and that your position is consistent with other setpoints in the CR3 TS. We do not concur widi your position. We have determirnt that the values for tie power-operated relief valve (PORV) lift setpoirt, pressurizer level and L'IDP enable temperature values speciful in tlx, TS slould be consistent with the nedxxiology desenhxl in de TS Bases 3.3.1. (see page B 3.3-10) for the Reactor Pnxecuon System and shouki be consenatively aijusted for instrument uncertainties. Accordingly, please submit a revised license amendmert request.
FPC RESPONSE:
\\
The values for the PORV lift serpoint, Pressurizer level, and LTOP enable temperature i
specified in the new proposed ITS Section 3.4.11, LTOPS, have been corrected to be consistent with the methodology described in the ITS Bases 3.3.1 for the Reactor Protection System as required by the NRC.
These values have been conservatively adjusted for instrument uncertainties had are included with FPC's revised license amendment request, LTOPS TFCRN 213, Revision 1.
~
L m
-Page 1-
_ U. S. Nucinar Regulatory Commission 3F1097-12 ( - Response to NRC RAI(LTOPS)
NRC REQUEST NUMBER 2 -
- We also r=r*d, in our August 12,1997 RAI, that the ternperatum ddference between the reactor coolant and the vessel metal at a distance one-fourth of the vessel wall thickness fmm the inside surface (i e quaner-t location) should be accounted into the da ui ion of the LTOP niable ternperature as is stated
= in the ASME Code Case N-514. Your September 5,1997 letter irrliced that 'your LTOP analysis is based on steady state or isothermal conditions and mnsidered the quaner-t metal ternperature to be equal to the water ternperature. 'Ihis is not consistent with the ASME Code Case N-514 and the NRC Branch Technical Position 5.2.2. Therefore, please account for de quarter-t temperature difference due to temperature gradient across the reactor vessel wall.
FPC RESPONSE:
ASME Code Case N-514 defines the LTOP enable temperature to be RTum + 50 deg for the -
- limiting material. This is 253*F for Crystal River 3 (CR-3) based on the 15 EFPY data. A note in N-514 specifies that this should be the temperature at 1/4T from the inside surface of the vessel wall.. The analyses performed to determine the limits for Low Temperature Overpressure Protection (LTOP) are based on an assumption that LTOP events are most likely to occur when the reactor is at steady state conditions. This assumption has been expanded in the CR 3 analysis and at other plants to mean that the reactor vessel is at isothermal conditions or that the temperature is constant through the-thickness of the vessel wall.
Using an isothermal assumption, the temperature at the vessel 1/4T location would be the same as at the inside surface of the vessel which is exposed to the water. ' In actuality there is some heat loss through the vessel wall aad the insulation,- and there would be some temperature gradient through :the wall.
In addition, heatup and cooldown operations twould add additional temperature differences between the quarter-t vessel location and the water.
-The reactor coolant temperature that is measured for LTOP is the water temperature entering-the reactor vessel since this is' the coolest temperature to which the vessel will be exposed.
- During cooldown operations, the quarter-t vessel temperature is higher than -the water.
temperature and monitoring the water temperature is conservative. During heatup operations, monitoring the water temperature is non-conservative, and during steady-state conditions where the RCS heatup has been suspended for a period of.at least 90 minutes, the quarter-t vessel temperature has been determined to be within 1 degree of the water temperature. This steady state gradien: has been evaluated using Newton's Law of Cooling and Fourier's Law.
A minimum water temperature of 254*F was used since the LTOP controls can not be exited
- until the temperature is greater than 253*F ( not corrected for instrument uncertainty).
Based on this evaluation, the temperature difference between the reactor coolant and the vessel
'1/4T location is less than 1*F. Steps will be included in the plant heatup procedure to require a reactor coolant system heatup holding period of 90 minutes after the enable temperature has been exceeded and prior to exiting the LTOP LCO. Therefore, the LTOP enable temperature
-limit of s 253*F (not corrected for instrument uncertainty) based on the water temperature is
-acceptable for use since the reactor vessel will be at steady state conditions and the vessel 1/4T location temperature will be above the enable temperature.
- -Page 2-L
U. S. Nuclear Regul0 tory Commission i:
- Enclosure 1. - Response to NRC RAI(LTOPS) _
NRC REQUEST NUMBER 3
[
Pieae desmbe the opermor actions to teminale an L'IDP event within 10' minutes.
3
[
FPC RESPONSE:'
The limits for LTOP were developed to provide the operators with at least 10 minutes to respond to and terminate an LTOP event before the limits are exceeded. The most limiting i
transient for LTOP is makeup injection through a stuck full open makeup valve. - During this -
- transient the makeup flow is approximately 340 gpm, and the MAKEUP FLOW HIGH alarm t
(160'gpm) would provide immediate indication of a potential LTOP event. Alarm response procedure, AR-403, directs the operators to observe LTOP_ concerns and refers to operating
{
- procedure OP-301, Operation of Reactor Coolant System (RCS),- for action required.
If
[
Pressurizer level or RCS pressure temperature limits confirm a LTOP event, the operators will
-immediately stop the operating makeup pump and take additional actions as necessary, For potential LTOP events due to-makeup flows less than 160 gpm, other alarms and 3
indications, although not specifically installed for LTOP, would be available which would alert the operators to take action. The most obvious indication would be alarms associated with the n
Automatic Closure Interface System (ACI). This system is used to protect the Decay Heat i
L System from overpressure, and is typically in operation at RCS pressures less than 284 psig and' temperatures less than 280 degF.
There are alarms which will indicate a potential
[.
pressurization event at 200 psig and at 284 psig. Alarm response procedure, AR-303, instructs the operator to investig.ite the cause of increasing pressure in the RCS, If this were a potential LTOP event, the operator would have about 20 minutes to diagnose and terminate the event by.
- stopping the operating makeup pump l.
1-
-If the ma':eup flow is less than 160 gpm and the ACI system is not active, other alarms would -
l actuate to alert the operators to a potential' overpressure event.
These alarms include -
Pressurizer level alarms at 200 inches and 240 inches (AR-501), At the time when the 200 inch alarm ac*uates, the operator would have more than 18.5 minutes to diagnose and terminate the event. A aitional alarms include the Makeup Tank low level alarms at 55 inches and 18 Linches (AR-403), and the_ RCS HIGH PRESSURE AT LOW TEMPERATURE alarm (AR-2i 501) at 50 psig below the PORV setpoint. Operators would have more than 15.7 minutes from the -55 inch alarm to mitigate the event,' and-more than 9.8 minutes from the RCS HIGH
' PRESSURE AT LOW TEMPERATURE alarm.
l The'following table lists the various alarms and the estimated tiining assuming a conservative makeup flow of 160 gpm. The table also assumes that the initial levels in the Pressurizer and the Makeup Tank are at the most limiting conditions of 160 inches and 100 inches, respectively.
-Page 3-
U. S. Nuclear Regulato. y Commission
+
3F1097-12 - Response to NRC RAI(LTOPS)
Alerms Time to Alarm Time to Limit (min)
(min)
MU flow high 160 gpm NA PZR low level (clear) 200 in 6.0 18.5 MUT low level 55in 8.8 15.7 PZR level high 240 in 12.0 12.5 3
RCS Press high 392.6 psig 14.7 9.8 PZR Level high-high 275 in.
17.3 7.3 PORV open setpoint
_ 442.6 psig 21.6 2.9 LTOP Limit @ 85 degF ' 464 psig 24.5 0.0 At higher RCS temperatures, the LTOP limits are greater than 464 psig, and more than 10 minutes would be available for operator response from the actuation of the RCS HIGH PRESSURE AT LOW TEMPERATURE alarm.
Given the availability and diversity of alarms which would alert the operators, and the relatively simple actions required to mitigate the event, there is a very good probability that the operators would be able to prevent an event from exceeding the LTOP limits.
l
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