ML20149M048
| ML20149M048 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 02/19/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20149M038 | List: |
| References | |
| NUDOCS 8802250274 | |
| Download: ML20149M048 (8) | |
Text
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8'g a 2 llego UNITED STATES l'
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NUCLEAR REGULATORY COMMISSION sm e
wAsmNotoN. D C. 20066
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SAFETY EVALUATION RY THF OFF'CE OF NUCLEAR REACTOP PEGUI.ATioN SUPDOPT!NG AMENDMEPT No. 104 TO rACILITY OPERAT'NG LICENSE NO. DPR '?
FLORIDA 00WED CORPORATION, FT AL.
CPYSTAL PtVFR UNIT NO. 3 NUCLEAP GFNEPATING PLANT DOCKET NO. 50-30?
INTRODUCTION Ey letter dated October ?6, 1987, as supplemented October 29, November 16, Novenber 70 and November 25, 1987, Florida Power Corporatine (FPC or the licensee) requested an amendnent to the Torhnical Specifications (TSs) appended to Facility Operating License No. DPR 72 for the Crystal Diver Unit No. 3 Nuclear Ganerating Plant (CR-31 The proposed amendment wnuld channe the emargency diesel generator surveillance requirements for inadino end auto-connected load verification in Technical Specifications (TS1 Section 4.8.1.1.?.d and the corresponding TS bases 3/4.8 to reflect the present load expactations.
PArKGROUND in August - Septanber 1.987, tha staff conducted an Operational Sa'ety Tean frsoectirn (OSTI) at Crystal Piver Unit 3.
Two o' the concerns raised by the OSTI concerned the Enargercy Diesel Generetnrs (EDGs) and were that:
1.
The accident load on the EDGs nay exceed the rating of the E04 The maxinum auto-connected accident load had been calculated as 3180 KW, and the addition of manually applied loads enuld exceed the 30-ninute rating of 3300 KW, In addition, if inlet combustion air temperatures to the FDG exceed 105'F, the EDG nay need to be derated.
2.
The licensee had been testing the EDGs at about 3100 KW, which was less than the then-calculated maximun accident load of 3180 KW, and which there-fore did not demonstrate the capabiH y of the EDGs to carry that load.
t TS 4.8.1.1.2.d.4 further requires that the EDG be tested every 18 months for 60 minutes or longer at a load of at least 3000 KW, However, the EDGs are rated at loads between 3000 KW and 3300 KW for only 30 minutes, in reviewing this situation and verifying loads, the licensee identified a power fector error in the load calculations. When the correct power factor was applied to the existino load calculations, the maximum auto-connected load exceeded the 30-nicute rating of the EDG. Diesel generator loads were thnn racalculated using conservative best estimates based on the actual equipment configuratier for each accident scenario and, after deleting certain loads not immediately needad for safety, it was determined that for all accident scenarios 8802250274 880219 DR ADOCK 050 32
. excaot two, maximum autn-connected FpG loads 'cr ene o' the two EDGs, EM "A",
would be within the 2000-hour rating.
Iloads on EDG "R" do not exceed the
'n00-hour rating fer any scenarin.) The two frenarios, involvino laroe and intermediate si:e less-of-coolant accidents (LOCAs), loss of of'sita power, and fcilure o' either EDG "B" or erergency feedwater pump "R", result in calcula+ed auto-cnnnacted loads in excess of the ?000-hour rating, but within the 30-minuta rating cf the diasal generator, and less than the oroonsed hichar test level of 3?4A YP as discussed below.
Certain auto-connected leads net needed 'or there scenarios, e.g., emergency feedwater pump, could and would be narus11y trippad prior to 30 minutes. Orepping these loads will reduce the load d* mand en EDG "A" to a level within the 2000-hour rating.
General Design Critarion-17 (GDC-17) recuires that the onsite newar supply (diesel cenerators) for nuclear plants ha nf suf'icient capacity and canahility to assure that:
I') specified acceptable fuel desion limits ard design condi-tions o' the reactor coolant pressure boundary are not excandad as a result of anticipatad operational occurrences, and I?) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. NRC Safety Guide 9 (and subsequently Pegulatory Guide 1.9) describes a basis 'or selection cf a diesel generator o' sufficient capacity to implemant GDC-17.
It indice.tes that predicted diesel generator loads shculd not exceed the icwer of the 2000-hour ratino or 90 percent of the 30-minute rating.
Since the maximum accident auto-connected load for the two accident scenarios exceeded the 2000-hour rating for up to 30 minutes until load managerent actions could be teken to reduce tha load, it was necessary for the licensee to either brire the plant into conformance with GDC-17 or to requast an exemption from G00-17 The licensee elected +o seek an exemption and to implement a short-tem solution to the EM 1eading problem while developing a long-tem pamenent solution.
Or December la, 1987, the licensee reouested a terporary exemption from the raouiraments of GOC-17, in accordance wi+h in OFR 50.1?(31, until the rext refuelirs outage to implement its interim solution.
A subsaquent letter on December 1G, ?cP7 provided further infomation and described testing which would be per#ormed to support the exemption reouest. The licansee had pre-vmusly identified various alternatives under consideration to bring the facility into compliance with GOC-17 and comitted to submit to the Comnission by March 30,19P,P its proposed innq-tem snlution and implemertatinn schadule.
On December 23, 1987, the Comission appenved an exemption fron the r'ouire-rants of G00-17 permittino the 'acility to operate with its predictad accident inads for EDG "A" within its 30-mirute ratino for not more than 30 minutes, orovided that:
(1) the principal estimated loads are confireed by test as described by the licensee, (2) operators are trained, and alarms and procedures are prnvided as described by the licensee, and (3) when reouired, a dedicated operator will be availeble for EDG load management.
This exemption is valid only through +he end of the next refueling outage.
The proposed amendment would change the surveillance requirements 'or the EDGs tn properly reflect their ratings and the predicted accident loads they wculd be evpected to carry. Also, the TS reouirement for verifying the auto-connected loads would be uodated to reflect the predicted loads in KW, 1
1
. Specifically, TS 4.8.1.1.2.d.a wculd be charged to reouire 18-month surve11-lance testire for 60 minutes, at he* ween 3748 KW and 3300 kW Iwithin the 30-ninute rating) for between 9 and 6 riinutes, and at between 2750 KW and 3000 KW (within the ?OOO-hour ratingi for the remainder of the 60 minutes.
In addition, TS 4.8.1.1.P..d.5 wou'd be chanced to require varifica+ ion that autr-conrected loeds do nn+ arceed 3248 KW.
EVAt.UAT!ON 1.
Diasol 1.cedinn The Crystal River Unit 3 ems are rated as follows:
Centinuous 3750 kW 7000 hours0.081 days <br />1.944 hours <br />0.0116 weeks <br />0.00266 months <br />
?751 - 3000 W 30 ninutes 3001 - 3300 KW The auto-connected loads in the original plant design were belcw *he 2000-hour ratirq n' the F Ms. However, loads have been added, the larcest being the motor-driven emergency feedwater pump.
This was added #c110 wing the TMI-2 accident. This additienal load had ircreased the calculated auto-conrected FM "A" load to within *he 30-minute rating rarce.
FPC letter dated May 1, 1980 acknowledged the 'act that the calculated EM 1ead would be within the 30-minute range efter *he addition of the aceroency feedwater pumo to the auto-corrected load, and comitted to future design charges to correct this situation.
FPC letter dated Fay 14, 1980 reported that preliminary test resulte indicated that the auto-corrected load would be wi+hin the ?OOO-hour ratirn. Although it is new rernonized that thesa +ests were not representative of actual accidents loads, the matter was apparer+1v dropped at that tim
- and not pursued subseouently.
Gilber+/Coernorwealth, Inc., tha licensee's architect /encineer, as reported in their 1r+ter of Neverber 4,1087, under provision o' 10 CFR 21, had used a j
power factor o' O.8 to determine the load VW in calculating the diesel generator loading during the original plant design.
In recent calculational updates, it vas deternined that the lead pewer factor is in the order of 0.9, yieldine a i
total KW load in excess of the diesel genereter 30-minute ratino, i
i Usire this power factor, the EM "A" auto-connected loads were calculated to be 3449 KW, with an additional 37? rW o' potential manually applied loads.
These leads exceeded the 30-minute rating, ralculations were then prepared bared on actuel brake hersepower ( W P1 require-ments c' tha pumps o' the various safety systems, instead of nameplate data as had beer previously used. The results of these calcu1etions were an automatic diesel generator loadino of 3370 KW with 370 KW of poter*ial manually epplied leads. These rewits also exceeded the EM 30-minute rating, i
Finally, analyses and calculatiens were prepared by FPC for different scenarios for each of the 'n110 wing design basis accidents coincident with loss o' offsite i
power erd failure o' either EDG "R" or emergency feedwater pump EFP-2.
j l
i
4-1.
Loss-of-Coolant Accident al Large Break i
b)
Interrediate Break c)
Small Break
?.
S+ean Line Break Accident al Inside Contairment bi Outside Containment 3.
Feedwater Lina Braak - Inside Containmert a.
Steam Generator Tube Rupture Syste.m flow recuirements were established for each pump 'or each of the above I
scanarios. These flow requirements wpre converted to pump BHP via test curves unicue to the individual pumps or calculated based on system carameters end
'inally to motor horseprwer and KW loadings via the motor nameplate efficiencies.
5 The staf' reviewed these scenarios, including equipment operation and systems flows, and sub.iect to review and approval of additional supportino documenta-tion as discussed below, found them appropriate, consistent with the system reouirements, reflectino reasonably conservative values, and therefor
- accepta-ble.
To reduce the EDG "A" loading, FPC haea (ai Pealigned motor control center 3AB to Rus "B".
(b) Provided for automatic load shedding o' the battery charger and of heat i
tracinq on EDG "A" The heat tracinq has two trains; primary train on EDG "A" and seenndary train en EDG "R".
(c) Recognized that manually adding control complex fans to the EDG can be i
dere after other load manacement actions have been taken.
(dl Committed not to align tha spare makeup pump WUP-19 to FDG "A", since it draws approximatelv 80 VW more than MVP-1A.
!* it should be necessary to align MUP-1R to EDG "A" in the future (only if MVP-1A wara nu+ o' service),
the TS action statement for an inoperable EDG would be entered.
In addition, automatic sheddirg o' the motor-driven emergency feedwater pump at the end of 30 minutes was deleted to improve EFW reliability for other scenarios for which it would be used.
This inad can still be shed manua119 i
These chances remove loads not inmediately recuired for safety, do not adverse'y affect the ability of the plant to mitigate accidents, and are therefore acceptable for the interin solution.
j i
Two single failure cases were assumed to calculate the maximum EDG loading.
a (a) Case 1 is failure of EDG "R", resultina in the emergency safety (ES) acuip-ment requirud for accident mitigation to be handled by FDG "A".
Loads nn erg "A" include the motor-driven emergency feedwater pump (EFW).
The l
. radundant E W pump is steam turbine-driven, thus EDM "R" doas not have an equivalent load because it does not include a motor-driven ErW pumo. There-fore, of the two EDGs, EM *A" has e creater calculated worst-case load requirement, which is less than 3248 KP, and wi+hin the 30-minute ratirg cf the EOG.
(bl Case 2 is tha failure of the steam turbine-driven auxiliary 'eedwatar pump "R", where both EDGs are available.
Thus, both trein A and P e' the ES aquipment ara available for operation and redundant sets o' ethe* ES pumps will be opere+ing in parallel.
In this case, EDG "A" it calculated to be loaded tn less than Case 1, and is also within tb 30-minuta ratinc.
These sinole feilures result in the hinhest EDG "A" loadino, end therefore, their use to determine the maximum FCG loading is deceotabla.
All scenarios, except twn, result in auto-connected leads on the EDGs which are within the continuous reting or the 9000-hour rating of the Ftrs, which satis-fios the reovirements of G0C-17.
The worst-cate scenarios, inte mediate or large-break loss-of-coolart accidant in con.4 unction with loss of n#fsite power and failure of Fnc "B" or emergency feedwater pump "B", result ie calculated auto-connected loads on EDG "A" within its 30-minute rating. As discussed above, the staff concluded that such operation does not satisfy the requirements of GDC-17.
The licensee has proposed interim ard long-term solutions with regard to GDC-17 For the lone *,erm solution, FPC 4 5+udying several option? to increase the diesel generator loading margins.
Amono these options are modi'"ing the existing diesels, replacino the diesels, or adding additionel on-site power sources.
The licensee has comitted to develop and implement a long-tem resolution which, alorg with an implementatinn schedule, will he submitted by March 30, 19P.8 for HPC review and approval.
The interin resolution proposed by the licensee util b es manual load manage-ment by the reactor operators to assure that EDG loads will not remain within the 'M-minute reting for longer than a total of 30 minutes.
To support this approach, the following actions have been taken:
1.
The major loads on the EDG have been tasted under conditions as c1cse as possible to expected accidant parameters to verify the calculated accider.t loads. Region II personnel have reviewed test orocedures and witnessed tests as feasible.
Preliminary test results have baan submitted bv 1etter dated January 7, 1988. Additional in'omation addressire testing and other concerns raised by the staff in a meating on Januery 20, loM, was subMtted by letter dated February 1,1988.
Infomation in these submittals, e1though not yet final, confims that *he test loads on the r.M are below the calcu-Sted value.
Flows fren SWP-1A and PWP-2A have been throttled by locked valves which will be replaced during the next refueling outage by fixed nrifices. The licensee states that the resultant flows are adequate to ersure performance of the system functions, and will document the basis
6-o
'or these changas.
Firal documentation n' test results is scheduled for submittal by the licensea by February 79, 1988, and is not expected to change the conclusier that measured loads are below the calculated values.
?.
Control room alarms have beer provided which will alert the operatnr5 initially when the diesels ara operatirp in the 30-minute ratino and again when 5, ?4. e.rd ?9 minutes of that period have expired. The aNed alarms will be loca*ed on tha electrical section of the annunciator ranet in order to place them ir close proxinity to the diesel generator inad YP me*er.
The added elapsed time indicator, which accumulates tha time the diesel generator opera *es above the 3000 KW loed level, will be loca*ed beinw the electrical section annuncia+or panel. Modificatinre to the centrol room nerels and annunciator system have been evaluated by the licensee 'n assure that information presented is clear and can be readily parceived by *he opere+ ors and that no new humar engineering discrepancies (HEDsi have haen introduced.
3.
Ocarators ara well-traired in the facility's s wntem-based emergency J
opere*ing procedures and have received additional +rainino and outdance to better eWo tharvelves to manage diesel cenerator loads hv tripping those which ara rot required for any earticular scenario in order to bring the 1eeds within the '000-hour rating in a tirely marner.
The licensee has stated tha* when load management is recessary, a dedicated eparator will be availabic to accomplish that furetion.
The licensee has abo implerented an EDG oad configuration managemant program for Cycle 7 to assure that EDG loads remain below the TS surveillance test value of raR KW. Battery load meregement should also be practiced as recessary
[
te assure maintenance of adeouate bettery canacity, particularly durino
~
the peried when the battery charger has been shed from the but,
~s Th'r interin solution is considereo acceptable by the s*aff only until the reyt scheduled refueling outege.
Autn-cornected EDG Ioads will exceed the 2000-heur ratino fer only two very unlikelu accident scenarios, are then only if loss of offsite power occurs and either EDG "B" or emergency feadwater pump "B" fails.
The licensee has supplied reliability assessments which indicate that tha probability of simultaneous occurrence of 41 the fgilures recescary to produce 1
3 the highest load nn EDG "A" is between 10~ and 10' Pased on the above, and sub,iect to review and appraval nf the final test renort and other supporting documertation, the tra#f concludas thet:
(1) the licensee's load calculations and prelinirary test results are aremotable, (2) loads nnt needed to nitigate any particular design basis accident scenario can he tripped within 30 minutes to bring the inad on EOG "A" to within the F000 hour rating, ard (3) the diesel generators will remain operable so that accider,t ennsequences previously analyzed will not be affected by tha nrnposed interim operation.
The steff therefore finds the proposed ir*.erim operation acceptab'ie for one re-fuelino cycle.
7.
Deleted EDG issues In the FPC letter of November 16, 1987, twn voltage dip tabulations resulting i
from block leadinq o' the EDG were submitted.
These voltace dim were ebtained (e) from load / voltage curves supplied by the diesel manufacturer, and (h) by
)
]
ca b ulation based on an aquation supplied by the diese? manufacturer. These j
i a
3
. voltage dip valuee were for the 4160V bus. These are acceptabla orevided that FPC ccnfirms these values by *esting not oniv the d.1 M V lavel, but also for the icw voltage (e.g., 480 volt level) o' +he onsite elec+rica1 dis +ri',ution system.
Another EM concern is the possible operttien of the EDG units with arbient r7m temperatures above 10F'F, which could rasult when the cutt,ide temparature is above 9E'F.
Derating of the EDGs is required above an air inlat tercaratura of 105'F.
In their letter of Novembar 20, 1987, FPC comitted te resolve this issue prior to the tine when ambient tempera +ures above nF'F are errected.
FPC should submit the specific resolution prior to March 30, 1988. 'or NRC review and approval.
3.
Tc Arendment As discussed above, the worst-case auto-connected EDG loading is calculated to be less than the higher testing level called for in the prnposed TS (3248 KV fer 5-6 minutes). The remainder of the one-hour test period would be between
??50 KW and 3000 KW (the 2000-hour rating o' the EDG).
Acoroval has been given, as discussed above, 'or plar' operation with diesel loads within the EDG 30-ninute rating for a total of no more than 30 minutes.
Thereafter, FDG operation would be within the 2000-hour rating. As discussed above, preliminary test results confirm that actual loads are below the calcu-lated loads. SWP-1A ard RWP-?A flows have haan throttled and the licersea states that the resultant flcws are adequate to assure performance of the system functions. The final test report and suoport for the reduced # lows will be submitted hv February 29, 1988.
Pased 9n the abcVe, the s+aff concludes that urtil the long-term solution is implemented, the proposed TS changes raflect the worst-case ineding of the E04, and would adeouately demonstrate the ability of the er.4stino EDG configuration to carry the predicted auto-connected accident inade without consumino an excessive amount of the allowable operating +ine within the 30-rinute rating, or exceeding tha+ rating.
Therefrre, subject to review and approval of the licersee's final test repor+
and supporting documentation, the staff concludes that the proposed TS chances are acceptable until the next refueling outace, by which tine the plant is to be in conformance with the requirements of GDC-17. At that time, prior to i
operation or to any EDG testing urder the affected TS sections, further revised TSs will be reouired.
ENVIPONMENTAL CONSIDERATION 1
This amendment involves a change in the installation or use of a facility component located within the res+ricted area as defired in 10 CFR Part 90 or changes to a surveillance requirement. We have determined that the amendment involves nn significant increase in the amounts, and no significant change in the types, of any effluents that ma.v he released r#fsite, and thet there 's no significant increate in individual or cumulative occupational radiation exprsure. The Commission has previously issued a prnposed findii,y J
.p.
that this amendrent involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment mea +s the eligibility criteria for categorical exclusion set #0rth in 10 CFR 51.??(c)(91 Pursuant to 10 CFR 51.??(b), no environmental impact statemant or environmental essessment need be prepared in connection with the issuance of this amendment.
CONCLllSION We have concluded, based on the consideretions discussed above, that:
(?.) there is reasonable assura.nce that the health and sefety of the public will not be endangered by operation ir. the proposed manner, and (?) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendrent will not be inimical to the cormon defense and security or to the health and safety of the public.
Dated:
February 19, 1988 i
Principal Centributors:
P. Jones S. Saba H. Silver