ML17083B839
| ML17083B839 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 12/09/1986 |
| From: | Schierling H Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-51638, NUDOCS 8612170287 | |
| Download: ML17083B839 (86) | |
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+y**4 UNITEDSTATES N~EAR REGULATORY COMMlSSION WASHINGTON, O. C. 20555 December 9, 1986 Do'cket Nos.
50-275 50-323 LICENSEE:
Pacific Gas and Electric Company
SUBJECT:
FACILITY:
Diablo Canyon Nuclear Power Plant, Unit 1 and Unit 2 MEETING SUYiYiARY - NATURAL CIRCULATION/BORON MIXING/
COOL DOMN'TESTS NRC staff and fts consultants.
from Brnokhaven National Laboratory (BNL) met with Pacific Gas and Electric Company (PRE) and westinghouse (M> on November 21, 1986 to discuss the BNL evaluation of the natural circulation, boron mixing and cool down test which had been performed in March 1985 at Diablo Canyon Unit 1.
The PGKE final test report had been submitted to the staff on March 25, 1986 (DCL-86-078).
The NRC meeting notice and a list of attendees are attached as Enclosures 1 and 2, respectively.
The staff stated that BNL had prepared for NRC staff review a draft repor t on its evaluation of the test.
.-The final,.
report will be included fn the staff evaluation, J.
Jo (BNL) presented a.summary of the BNL. evaluation 'and conclusions usinq the vfewgraphs attached as.
BNL reached the following conclusions:
II il 1)
The test demonstrated that adequate natural circulation was established and the plant was capable of removing the decay heat by natural circulation using only safety-grade equipment.
2)
Adequate boron mixing could be achieved by natural cfrculatfon in the main flow path'f the RCS using only safety-grade equipment.
I 3)
The effect of relatively unborated water entering the RCS from the upper head and pressurfzer
.appears to be minimal as long as depres-,
surfzation is conducted carefully to limit the size of possible void formation.
4)
The pressure would rise and reach the PORV actuation pressure without letdown during the boron mixing period.
5)
,The test demonstrated that the main RCS can be cooled down to the RHR system initiation temperature while maintaining adequate subcooling during the natural circulation usfng only safety-grade equipment.
6)
The test demonstrated that the upper head could be cooled without void fnrmatfon when the CRDM fans were in operation.
/r f
/
2 7)
The test results indicate that the upper head cooldown rate without the GRDCE fans is about 6'F per hour.
This is higher than the conser-vative BNL calculation (accounting only for conduction heat loss) which estimated a minimum rate of 3'F per hour.
The PCS pressure should be maintained above 1200 psia by means of either the pressurizer heaters (if available) or charging during the cooldown period to avoid the void formation in the upper head when the CROM fans were not in operation.
9)
Sufficient supply of safety grade cooling water was available to support the proposed plant cooldown method even if the CROM fans were'not available for the Diablo Canyon Plant but the worst case requirements (360,000 gallons) may not be available at all plants.
10)
Only one motor-driven AFW pump was needed to supply the necessary coo1inq water throughout the transient.
11)
Sufficient ASD valve capacity was available to support the cooldown even when the cooldown rate was 50'F per hour.
l I
12)
The availability of the pressurizer heaters and letdown system, while not essential, would affect the operational procedures in a ma,ior'ay.
The strategy to reduce the upper head cooling time by intentionally forming a void may be difficult to perform without pressurizer heaters.
Some plants appear to have the capability to control voiding by charging and venting through reactor vessel head vents.
13)
The RCS pressure would increase and stay high, and the POPV may be
'actuated periodically if the letdown system was not available, due to the boron injection and the continuous injection of RCP seal flow.
The operation of the auxiliary pressurizer spray normally requires letdown to be in operation to prevent the possihle thermal stress on the charging nozzles.
14)
Additional information is needed from Westinghouse on the details'f its estimation for the upper head cooling time without the CRDH fans.
(The BNL analysis and the test data indicated that the cooling period should be substantially longer than the 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> estimated by Westinghouse).
The staff stated that these were BNL conclusions which the staff had not yet evaluated as of the time of the meeting.
The major subjects of discussion were the cooldown and mixing of the water in the upper head.
The factors of significance include the direction of flow through the upper head, the potential for stratified flow in the lower layers of the upper head leaving a relatively undisturbed volume in the upper layers, the heat conduction along the CRDMs to the outside which act as cooling fins, the effect of upper head internal structures on
mixing, the heat loss from the upper head with and without the CRDM cooling fan's operating, and the effect of the Westinghouse "T-hot" and "T-cold" plant upperhead designs.
Westinghouse stated that good mixing cooldown should be assumed for all Westinghouse plants.
To evaluate the cooling effect of the CRDM fans (assumed not to be available during natural circulation cooldown} the fans were turned off; at 18.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after initiation of the test.
The temperature of the upper
- head, as measured with a thermocouple mounted on the upper head, increased for approximately one hour and then decreased steadily for about one half hour after which the fans were turned on again.
Westinghouse calculated an upper head cooldown rate of about 6'F per hour while BNL, usinq conservative assumptions, estimates a cooldown rate of 3'F per hour.
The staff stated that, based on the information discussed by Westinghouse during the meeting, no additional information appeared to be necessary to complete the evaluation of the test for the Diablo Canyon Plant.
BNL will prepare a final report for the NRC staff which will be the basis for the staff's Diablo Canyon Safety Evaluation.
Regarding the applicability of the Diablo Canyon'test to other Westinghouse plants, staff requested BNL to identify by early December specific additional information needed for the evaluation, which will then be issued by the staff to PGKE and Westinghouse for response.
The staff/BNL will review the information and conclude on the applicability of the Diablo Canyon test to other Westinghouse Plants.
Enclosures:
As stated Hans Schierling, Se r Project Manager Project Directorate P3 Division of PWR Licensing-A cc:
See next page
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Mr. J.
D. Shfffer Paciffc Gas and Electric Company Diablo Canyon CC:
Philip A. Crane, Jr.,
Esq.
Pacific Gas 5 Electric Company Post Office Box 7442 San Francisco, California 94120 Mr. Malcolm H. Furbush Vice President'-
General Counsel Pacific Gas 5 Electric Company Post Office Box 7442 San Francisco, Calf fornia 94120 Janice E. Kerr, Esq.
California Public Utilities.Commission 350 McAllister Street San Francisco, California 94102 Hr. Frederick Eissler, Presfdent Scenic Shoreline Preservation Conference, Inc.
4623 Nore Hesa Drive Santa Barbara, Calffornia 93105 Ms. Elizabeth Apfelberg 1415 Cozadero San Luis Obispo, California 93401 Hr. Gordon A. Silver Ms. Sandra A. Silver 1760 Alfsal Street San Luis Obispo, California 93401 Harry M. Willis, Esq.
Seymour 5 Wfllfs 601 California Street, Suite 2100 San Francisco, California 94108 Hr. Richard Hubbard MHB Technical Associates Suite K
1725 Hamilton Avenue San Jose, Calf fornfa 95125 Arthur C. Gehr,'sq.
Snell 5 Wilmer 3100 Valley Center Phoenix, Arizona 85073 NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. 0.
Box 369 Avila Beach, California 934?4 Ms.
Raye Fleming 1920 Pattie Road Shell Beach, California 93440 Joel
- Reynolds, Esq.
John R. Phillips, Esq.
Center for Law in the Public Interest 10951 West Pico Boulevard Third Floor Los Angeles, California 90064 Nr. Dick Blankenburg Editor 8 Co-Publisher South County Publishing Company P. 0.
Box 460 Arroyo Grande, California 93420 Bruce Norton, Esq.
Norton, Burke, Berry 5 French, P.C.
202 E. Osborn Road P. 0.
Box 10569 Phoenix, Arizona 85064 Nr.
W. C. Gangloff Westinghouse Electric Corporation P. 0. Box 355 Pittsburgh, Pennsylvania 15230 David F. Flefschaker, Esq.
P. 0.
Box 1178 Oklahoma City, Oklahoma 73101 Nanaqfng Editor San Luis Obispo County Telegram Tribune 1321 Johnson Avenue P. 0.
Box 112 San Luis Obispo, California 93406
Pacific Gas 8 Electric Company Diablo Canyon CC:
Dr.
R.
B. Ferguson Siera Club - Santa Lucia Chapter Rocky Canyon Star Route
- Creston, Cali fornia 93432 Mr. Leland M. Gustafson, Manager Federal Relations Pacific Gas h Electric Company 1726 M Street, N.W.
Suite 1100 Washington, DC 20036-4502 Regional Administrator, Region V
U.S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Michael J. Strumwasser, Esq.
Special Counsel to the Attorney General State of California 3580 Wilshire Boulevard, Suite 800 Los Angeles, California 90010 Mr. Tom Harris Sacramento Bee 21st and 0 Streets Sacramento, California 95814 Ms. Jacquelyn Wheeler 2455 Leona Street San Luis Obispo, California 93400 Lewis Shollenberger, Esq.
US Nuclear Regulatory Commission Region V
1450 Maria Lane Suite 210 Walnut Creek, California 94596 Mr. Thomas Devine Government Accountability project Institute for Policv Studies 1901 Que Street, NW Washington, DC 20009 Chairman San Luis Obispo County Board of Supervisors Room 220 County Courthouse Annex San Luis Obispo, California 93401 Director Energy Facilities Siting Division Energy Resources Conservation and Development Comnission 1516 9th Street Sacramento, California 95814 President California Public Utilities Comission California State Building 350 McAllister Street San Francisco, California 9410?
Mr. Joseph
- 0. Ward, Chief Radiological Health Branch State Department of Health Services 714 P Street, Office Building 88 Sacramento, California 95814 Ms. Nancy Culver 192 Luneta Street San Luis Obispo, California 43401 Ms. Laurie McDermott, Coordinator Consumers Organized for Defense of Environmental Safety 731 Pacific Street, Suite 42 San Luis Obispo, California 93401
p )'
November 13 1986 Docket No. 50-275 MFMORANDUM FOR:
FROM:
SUBJECT:
Steven A. Varga, Director Project Directorate P3 Division of PWR Licensing-A Hans Schierling, Senior Project Manaaer Proiect Directorate h3 Division of PWR Licensing-R FORTHCOMING MEETING WITH PACIFIC GAS AND ELECTRIC COMPANY DATE In TIME:
LOCATION:
PURPOSE:
November 21, 1986 8:30 a.m; - 2:30 p.m.
7920 Norfolk Ave.
NRC Offices, Room P-110
- Bethesda, Maryland Discussion of Natural Circulation, Boron Mixing, and Cooldown Test with PGEE and Westinghouse.
PARTICIPANTS:
NRC H. Schjerling C. Berlinger B. Mann J. Wilson R. Lohel T. Marsh C. Liang E. Branagan S.
Diab K. Perkins (BNL)
J.
Joe (BNL)
PGSE B. Lew M. Norem et al.
A. Cheuno (W)
R.
Sermon (W) cc:
See next page Hans chic ling, Senior Proiect Manager Project Directorate 83 Division of PWR Licensing-A
Contact:
H. Schierling (301) 492-8856 PD83 HSchi ng 11 86
0
H. Schierling C. Berlinger B. Mann R. Lobel J. Watt J. Wilson E. Branagen I
l LIST OF PARTICIPANTS I
NRC/PG&E MEETING i November 21, 1986 I
ENCLOSURE 2
J. Jo K. Pet king M. Norem T. Libs B. Giffin A. Cheung R.
Swram R. Off M. Miller P. HoHale
0
REVIEW OF
.. - NATURAL C I RCULATIOH, BORON MIXIHG AND COOLDOWH TEST AT DIABLO CANYON J.H-JO, N. CAVLINA AND K.R-PERKINS CONTAINMENT R SYSTEMS INTEGRATIOH GROUP DEPARTMENT OF NUCLEAR ENERGY BROOKHAVEN NATIONAL lABORATORYg) g) g ASSOCIATED UNIVERSITIES, INC.(ll.ll
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TO ASSIST THE NRC STAF IN EVALUATING DATA AND SUPPORTING ANALYSES OBTAINED FROM THE NATURAL CIRCULATION, BORON NIXING AND COOLDOHN TEST PERFORMED AT DIABLO CANYON UNIT 1 IN COMPLIANCE MITH THE BTP RSB 5-1 REQUIREMENT FOR A CLASS 2 PLANT-BROOKHAVEN NATIONALLABORATORYl)g$ $
ASSOCIATED UNIVERSITIES, INC. Cllll
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'2: 58 3:22 3:28 3:43 7:20 16:26 20:35 21:01 22:45 25:15 21:30 00:28 00:52 00:58 01:13 04:50 13:56 18;05 18: 31 20:15 22:45 PLANT TRIP RCP TRIP BORON INJECTION INITIATED PORV OPEN BORON INJECTION TERMINATED COOLDOMW INITIATED (20'F/HR)
DEPRESSURIZAT ION INITIATED (8 PSI/HR)
RHR SYSTEM INIATIATED CRDM FANS SECURED CRDM FANS RE-ENERGIZED END OF TEST BROOKHAVEN NAT(ONAl MBORATORYt) hjt ASSOCIATED uNIVERSITIES, INC. (h K.hh
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RELAP5/MOD1
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MINIMUM NUMBER OF NODING; ALL FOUR LOOPS
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VESSEL
- STEAM GENERATORS PRESSURIZER UPPER HEAD BYPASS FLOM RCP SEAL INJECTION
- HEAT STRUCTURES (FUEL, PIPING, U-TUBE, ETC
)
PRESSURIZER HEAT LOSS REl IEF VALVES AFM
- ASD VALVES SEVERAL SENSITIVITY CALCULATIONS PERFORMED 20'F/HR COOLDOMN MITH RCP SEAL INJECTION MITHOUT RCP SEAL INJECTION 5P'F/HR COOLDOMN BROOKHAVEN NATIONAL tABORATORYI)gy t ASSOCIATED UNIVERSITIES, INC.(lllI r
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ASDV TSV RV AFW MFW STEAM DOME SEPARATOR poR v GENERATOR PRESSURIZER UPPER HEAD HOT LEG UPPER DC UPPER PLENUM PUMP COLD LEG DC DC CORE UPPER PLENUM 80RON INJECTION LOWER PLENUM Figure 3.1.
Noding diagram.
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TABLE 3-1 THE STEADY STATE CONDITIONS PARAMETERS PLANT RELAP5/MOD1
- POMER, MM
- PRESSURE, PsIA HOT LEG TEMP, 'F COLD LEG TEMP-, 'F COOLANT FLOW, I B/sEG BYPASS FLOW, IB/sEc hP PUMP PSIA PRESSURIZER LEVEL, X STEAM PRESSURE, PsIA STEAM TEMPERATURE, 'F STEAM FLOM, LB/sEG SG MATER VOLUMEp FT BORON CONCENTRATION, PPN 3338 2252.8 608.8 544-4 36918 77-3 84-0 60 0
805-0 519-0 4039 7930 890 3338 2252-8 612-1 548-0 36678 79-6 84-6 61.7 805.0 518 9
4035.8 7068-0 890 BROOKHAVEN NATIONAL LABORATORYg) ly g ASSOCIATED UNIVERSITIES, INC.(I R.l I
1)
THE TEST DENONSTRATED THAT ADEQUATE NATURAL CIRCULATION HAS ESTABLISHED AND THE PLANT NS CAPABLE OF RENOVING THE DECAY HEAT BY THE NATURAL CIRCULATION USING ONLY SAFETY-GRADE EQUIPMENT-BROOKHAVEN NATIONAL IABORATORYf7 gy g ASSOCIATED UNIVERSITIES, INC.(I LII
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0
4000 CALCULATED BY RELAP 5/MOD'I
-- PRE-TEST PREDICTION BY PG & E 3000
<K 2000 O
l 000
~
I 0
2000 4000 6000 8000 10000 l2000 TlME, sec Figure 3.2 RCS floe.
P.
600 0
~ 500 I-
~ ~00
HOT LEG TEMP.
COLD LEG TEMP.
UPPER HEAD TEMP.
WITH PERFECT Ml/ING I
I.
0
!OOOO 20000 TtME, sec 50000 Figure 3.4 The calculated RCS temperature (20'F/hr cooldown).
600 THol 500 TCoM 4
~~ 400 I
THol TColl 300 200 COUQENCE COOLOONN TRIP PLANT TRP RCPo QAIXTAIN HOT STANMY ONE CROV FAN OE'j (08<5 HRS)
COOLOOIIN USING STEAII OIL/PS 3 CROV FANS ON (TOIT HRS)
ALL CRO'll FANS OFF (l835 HR5) l0% ATIIOSPHER IC.
.INITIATE RHR C
CLOOIIN USING R
R 2I30 2000 0200 0400 0600 0800
. I000 l200 I400 l600 I800 2000 2200 CLOCKTIME (HRS)
Figure 3.6 RCS temperature for the test.
5
2)
ADEQUATE BORON NIXING COULD BE ACHIEVED BY THE NATURAL CIRCULATION IN THE HAIN FLOM PATH OF THE RCS USING ONI Y SAFETY-GRADE EQUIPNENT-BROOKHAVEN NATIONALMBORATORYm) gy t ASSOCIATED UNIVERSITIES, INC.(I LI 1
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F 500 TEST LOFT ( W PRE-TEST
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RELAP 5
( BNL)
-- UPPER HEAD ( BNL; PERFECT MIXINGASSUMPTION)
O z 200 z'00 s
/
r
///////
0 IO 20 30 40 50 60 70 80 90 TIME (min)
Figure 3.9 Boron concentration.
5)
THE EFFECT OF RELATIVELY UNBORATED MATER ENTERING THE RCS FROM THE UPPER HEAD AND PRESSURIZER APPEARS TO BE MINIMALAs LONG As DEPRESSURIZATION Is CONDUCTED CAREFULLY TO LIHIT THE SIZE OF POSSIBLE VOID FORMATION-BROOKHAVEN NATIONAL lABORATORYt) gy t ASSOOATED UNIVERSITIES, INC.(I Lll
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THE PRESSURE MOULD RISE AND REACH THE PORV ACTUATION PRESSURE MITHOUT LETDOMN DURING THE BORON BIXING PERIOD-BROOKHAVEN NATIONAL lABORATORYt7 gy g ASSOCIATED UNIVERSITIES, INC.(IlI m
111 2400 O 2000 I 600 (n
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400 rr I
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PRESSURE
- PRESSURIZER LEVEL 1
IOO 80
~O 0
60 ~
40 N 20 0
l0000 20000 TIME, sec 30000 40000 Figure 3.5 RCS pressure and pressurizer level (20'F/hr cooldown).
0
/
PRESSURIZER LEVEL.4 PRESSURIZER PRESSURE va TIME 2800
~ 70
) 60 LLJ 50 0
Ul 40 tLJ 0
30 20 PORV PCY.456 CTCLEO 9 TIUES IXITIATEO LETOOXX IXITIATEO l.ETMXN (OS35 IIRS)
~PER PRESS IXITIATEO LETOQWN (OI50 IIS)
COQQEXCEO KPRESS USING AUX.
SPRAY IeS IIS)
~PlR LEVEL LSOLATEO OPEN PORV LE'IOQXN
~PCY.<5G TO (ISle IHS)
KPRESSURflE
. ISOLATEO ISOLATED LETOOETN LETOONN (oiso lis) foa>> lis)
UAINTAIX
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COOLOOXN USIIIG IOX ATIIOSPHERIC STEAQ RIllPS LRJ L/l L/l LRJ CX:
tl LLJ t/l L/1 LLJ CEtt 2400
- 2000
, l600 II' I200 800 400 lo NIP ROT STANIHY fXJECT BIT FINISU (OID ITIS)
TRIP RCPJ R INJECT BIT SMT (oo>a Ims)
(OOSZ WS)
USING RINI INITIATE RITI
., (laos RRs)
ZI3O 2<00 OZOO 0400 O6OO O80O IOOO IZOO
(<00 I6OO I8OO ZO0O ZZ0 CLOCK TIME (HRS)
Figure 3.7 Test pressure and pressurizer level.
5)
THE TEST DENONSTRATED THAT IT COULD COOL THE NAIN RCS TO THE RHR SYSTEtt INITIATION TENPERATURE AWHILE HAINTAINING ADEQUATE SUBCOOLING DURING THE NATURAL CIRCULATION USING ONLY SAFETY-GRADE EQUIPNENT-BROOKHAVEN NATIONAI. lABORATORYg) gy t ASSOCIATED UNIVERSITIES, INC.(IIII
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700 IL, 600 I-ILII-500
TEST HOT LEG TEMP.
SAT. TEMP. OF TEST PRESS.
"CALCULATED HOT LEG TEMP.
SAT. TEMP. OF CAI CULATED
~PRESS.
400 I0000 20000 TIME AFTER BEGINNING OF COOLDOWN, sec Figure 3.11 Hot leg and saturation temperature of test and calculation (20'F/hr cooldown).
~
~
600
RCS TEMPERATURE
0
~a 500 I-0 IOOOO 20000 TIME AFTER BEGINNING OF COOLDOV/N, sec Figure 3.12 RCS temperature.and saturation temperature with 50'F/hr cooldown.
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HE ER EAD DER Co I S
A)
HEAT REMOVAL FROM THE UPPER HEAD !NTO THE CONTAINMENT ENVIRONMENT THROUGH THE CRDM AND THE UPPER HEAD DOME WHEN CRDM FANS OPERATE, 9)
AMOUNT OF BYPASS INTO THE UPPER
- HEAD, C)
HEAT CONDUCTION FROM UPPER HEAD TO UPPER PLENUM TflROUGH THF GUIDE TUBE STRUCTURES, D)
HEAT CONDUCTION DOWN TO THE REACTOR VESSEL THROUGH THE UPPER HEAD DOME-BROOKHAVEN NATIONAL lABORATORYg) gq g ASSOCIATED UNIVERSITIES, INC. (ll II.I H.
6)
THE TEST DEMONSTRATED THAT THE UPPER HEAD COULD BE COOLED MITHOUT VOID FORMATION MHEN THE CRDM FANS MERE IN OPERATION-BROOKHAVEN NATIONAlLABORATORY gy gy t ASSOCIATEO UNIVERSITIES, INC.(IllI
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0 700 600 500
UPPER HEAD TEMPERATURE
-- SAT. TEMIPERATURE OF RCS PRESSURE WITH 50 Flhr COOLDOWN SAT. TEMPERATURE OF RCS PRESSURE WITH 20 F/hr COOLDOWN L
400 5
IO TIME AFTER BEGINNING OF COOLDOWN, hr l5 Figure 4.1 Margin of subcooling in the upper head with CRDt< fans in operation.
I
7)
THE TEST RESULTS INDICATE THAT THE UPPER HEAD COOLDOWN RATE WITHOUT THE CRDH FANS IS ABOUT 6'F PER HOUR THIS IS HIGHER THAN THE CONSERVATIVE BNL CAI CULATION (ACCOUNTING ONLY FOR CONDUCTION HEAT LOSS)
WHICH ESTINATED A llINIMUH RATE OF 3'F/HOUR-BROOKHAVEN NATIONAllABORATORYg7 gy m ASSOCIATED UNIVERSITIES, INC.(lllI
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VESSEL Fulgur e 3.8 Bypass flo~,
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FLUID PATH HEAT COND PATH
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600
"""- NODE 1 (UPPERMOST REGION)
NODE 2 "NODE 3
NODE 4 (BOTTOM REGION) 500 Ld t--
LL LU 400 300 0
IO 20 30 40 50 TIME AFTER BEGINNING OF COOLDONN, hr Figure 4.2 Upper head temperature when loss is due to conduction only (25'F/hr cooldown of RCS).
8)
THE RCS PRESSURE SHOULD BE MAINTAINED ABOVE 1200 PS IA BY MEANS OF EITHER THE PRESSURIZER HEATERS (IF AVAILABLE) OR CHARGING DURING THE COOLDOWN PERIOD TO AVOID THE VOID FORMATION IN THE UPPER HEAD MHEN THE CRDM FANS MERE NOT IN OPERATION-BROOKHAVEN NATIONAL lABORATORYgy gy g ASSOCIATED UNIVERSITIES, INC. IIllI 5
600
UPPER HEAD TEMP.
0 CL
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500 400 lO
. 20 30 40 50 60 TlME ATER BEGlNNING OF COOLDOWN, hr p'figure 4 ~ 3 Upper head temperature and saturation temperature of RCS pressure with 20'F/hr cooldoNn,
9)
SUFFICIENT SUPPLY OF SAFETY GRADE COOLING MATER MAS AVAILABLETO SUPPORT THE PROPOSED PLANT COOLDOMN NETHOD EVEN IF THE CRDN FANS MERE NOT AVAILABLEFOR THE DIABLE CANYON PLANT BUT THE HORST CASE REQUIRENENTS (360,000 GALLONS) HAY NOT BE AVAILABLEAT ALL PLANTS-BROOKHAVEN NATIONAllABORATORYmygy g ASSOCIATED UNIVERSITIES, INC.(IllI
O l500 IOOO 500 50~ F/hr COOLDOWM 20'r hr COOLDOWN 5000 IOOOO I5000 20000 25000 50000 TIME AFTER BEGINNING OF COOLDOWN, sec Figure 3.15 Accumulated cooling water.
C3
10)
ONLY ONE 010TOR-DRIVEN AFM PUtlP MAS SUFFICIENT TO SUPPLY THE NECESSARY COOLING MATER THROUGHOUT THE TRANS IENT-BROOKHAVEN NATIONAI. lABORATORYg7 yyt ASSOOATED UNIVERSITIES, INC. (m KlI
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SUFFICIENT ASD VALVE CAPACITY WAS AVAILABLETO SUPPORT THE COOLDOWH EVEN WHEN THE COOLDOMH RATE MAS 50'F/HOUR.
BROOKHAVEN NATIONAL lABORATORYg7 gy m ASSOCIATED UNIVERSITIES, INC. (Nllm
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80
50'/hr COOLDOWN 20'/hr COOLOOWN:.
60 o
40 LLI N
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5000 I0000 I5000 20000 TIME AFTER COOLDOWN, sec Figure 3.14 Atmospheric steam dump valve opening.
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12)
THE AVAILABILITYOF THE PRESSURIZER HEATERS AND LETDOWN SYSTEN, MHILE NOT ESSENTIAL, MOULD 'AFFECT THE OPERATIONAL PROCEDURES IN A NAJOR MAY-THE STRATEGY TO REDUCE THE UPPER HEAD COOLING TINE BY INTENTIONALLYFORNING VOID BAY HOT BE DIFFICULT TO PERFORN MITHOUT PRESSURIZER HEATERS.
SQHE PLANTS APPEAR TO HAVE THE CAPABILITY TO CONTROL VOIDING BY CHARGING AND VENTING THROUGH REACTOR VESSEL HEAD VENTS-BROOKHAVEN NATIONAL LABORATORYmy gy g ASSOCIATED UNIVERSITIES, INC.(ILII
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13)
THE RCS PRESSURE MOULD INCREASE AND STAY HIGH, AND THE PORV l'lAY BE ACTUATED PERIODICALLY IF THE LETDOMN SYSTBl MAS NOT AVAILABLE, DUE TO THE BORON INJECTION AND THE CONTINUOUS INJECTION OF RCP SEAL FLOM-THE OPERATION OF THE AUXILIARY PRESSURIZER SPRAYER NORNALLY REQUIRES LETDOMN TO BE IN OPERATION TO PREVENT THE POSSIBLE THERNAL STRESS ON THE CHARGING NOZZLES.
BROOKHAVEN NATIONALlABORATORYg)gy g ASSOCIATED UNIYERSITIES, INC.(ltlI
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14)
IT IS RECONNENDED THAT MESTINGHOUSE PROVIDE THE DETAILS OF ITS EST INATION FOR THE UPPER HEAD COOLING TINE MITHOUT THE CRDt'l FANS.
(THE BNL ANALYSIS AND THE TEST DATA INDICATE THAT THE COOLING PERIOD SHOULD BE SUBSTANTIALLY LONGER THAN THE 8 HOURS ESTINATED BY WESTINGHOUSE)-
BROOKHAVEN NATIONALlABORATORYg7 gy g ASSOCIATED UNIVERSITIES, INC. (5lII
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