NUREG-0999, Minutes of 771111 Workshop on Simulation of Nuclear Fuel Rods in Loca.Viewgraphs Encl
| ML20132F098 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/1978 |
| From: | Picklesimer M NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20132A685 | List:
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| References | |
| FOIA-83-619, RTR-NUREG-0999, RTR-NUREG-999 NUDOCS 8507180261 | |
| Download: ML20132F098 (2) | |
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NUCLEAR REGULATORY COMMISSION
- ,h WASHINGTON, D. C. 20555
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MAR 31 1978 0
MEMORANDUM FOR: File j FROM: M. L. Picklesimer !
Fuel Behavior Research Branch I
SUBJECT:
MINUTES OF WORKSHOP ON SIMULATION OF NUCLEAR E FUEL RODS IN LOCA, NATIONAL BUREAU OF STANDARDS, !'
GAITHERSBURG, MD. NOVEMBER 11,1977 q '
As a result of discussions held by the UKNII, the USNRC, and the l' FRGBMI on June 29, 1977, in London, England, a workshop was planned and held in conjunction with the WRSR Annual Information Meeting, ,
NBS, November 7-11, 1977. The objective was to examine the latest l -
information on the behavior of Zircaloy fuel cladding during '
ballooning and bursting by transient and isothermal heating, the .'
effects of different methods of heating, and the behavior predicted for nuclear ~ heated fuel rods in a LOCA. The agenda of the workshop .>
is attached as Enclosure A and was followed except for the addition .
of a presentation by T. Healey, Central Electricity Generating -
i Board, England, on " Analysis of Axial Ballooning Behavior of W Directly Heated Zircaloy Tubes." The attendence list is given in *R Enclosure B. Copies of the available handouts of the meeting are attached.
The meeting.was convened at 9:20 by the Chairman (M. L. Picklesimer,
, NRC) with an introduction into the justification and objectives of the workshop.. He then discussed his analytical examination of the extended axial ballooning (reported by Hindle) from the standpoint of a " negative feedback" control of local ballooning which is inherent in Joule-heated tubes having " cold" surroundings. The <
principal conclusion was that for specimens ballooning at temperatures
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in the. alpha-phase range there was a temperature of the surroundings below which extended axial ballooning would be observed and cbove
, which it would not. If the specimen was at 800'C, then this Since a fuel rod in a nuclear temperature was approximately 570*C.
heated fuel bundle would not "see" surroundings uniform in temperature and more than 200'C colder than the fuel' rod, the extended axial ^l ballooning observed by Hindle in a controlled laboratory test could not occur in a real reactor in a real LOCA.
D. O. Pickman then presented the work on extended axial ballooning '
conducted by E. D. Hindle at the Springfields Laboratory (UKAEA). ,
- The tests are conducted by Joule heating of single Zircaloy fuel tubes severely restrained by internal alumina pellets and exposed 'l to low temperature steam in surroundings at a temperature of not .
g greater than 70-80*C. Hindle has extended the temperature range ..
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, i 2- M 31 1978 in which extended axial ba11 boning can be observed to 890 to 1150 K.
He also concludes that greatly increased or decreased internal pressures are not an adequate solution to the problem of extended axial ballooning.
W. A. Fiveland, Babcock and Wilcox, discussed the work he and others at the B&W Alliance, Ohio installation had conducted on transient heated burst tests in argon of single and multirod tests of Zircaloy
. cladding heated by internal radiant heaters (tungsten filaments in
- quartz tubes), with shaped heated shrouds. They observed no extended axial ballooning, and found local balloons (with burst) only a few
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tube diameters in length. -
y T. Healey, Berkeley Nuclear Laboratories, UK Central Electricity -
Generating Board, England, presented the work and analysis he had .
done with Clay and Duffey in an analysis of the Hindle results.
He concluded that the extended axial ballooning observed was an artifact of the test method as a result of a coupled heat transfer-
- creep deformation mechanism which allows a localized strain perturbation to cool preferentially and force neighboring regions to begin to
~q, i strain. He emphasized that results from Joule heating experiments should not be used to infer the thermal and deformation response of
- l. tubes heated by internal elements, or by decay heat from nuclear fuel.
After a coffee break, D. L. Bunnan, Westinghouse Nuclear Fuels Division, presented an analysis of experimental results on circumferential temperature gradients produced in Zircaloy fuel cladding by off-center .
- fuel pellets during transient heating. His measurements indicate that j circumferential temperature gradients of 40*F and more can be expected -
at any axial position in pelleted fuel rods during transient heating r
at 25'F/second. i,
, The very recently obtained creep-rupture tests on Zircaloy fuel cladding obtained at ORNL in the MRBT program were then reported ,
by R. H. Chapman. Using an internal conduction heater (electrically haated) for simulation of the nuclear fuel, creep-rupture tests having nominally 50,100,160 and 250 seconds to rupture at 760*C had essentially the same burst strains and axial strain profiles as H shown by specimens burst in transient heating at nominally 50 F/second using the same two heaters as in the creep-rupture tests. No extended -
axial ballooning was observed, and comparison of the creep-rupture result;s with the transient heating results indicates that there is no effect of heating rate at rates of 0 and 50*F/second when an internal conduction heater is used in his test. ,
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F.( Erbac'h'er, GfX-KarlAruhe, Federal Republic of Germany, presented the 6 results 'obtained in Sii;gle rod tests in the PNS program using internal
'(, conduction heaters of,a different design than the ORNL heaters and at aaslosir heatir,g; rate. Their experimental results confirm those v i !
a, e iobtained by Chapman at ORNL except that the circumferential strains
! $weresomewhatgrAater. In addition, Erbacher presented the results '
L of severaliin-pile tests, using n'uclear heated rods, which were in excellent agreement with those tests conducted out-of-pile, in both t
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- 3 burst strains and axial strain profiles. [-
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The effects of circumferential and axial temperature gradients
', l produced by internal pellett during' transient heating (Joule) burst kr d
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, tests were discussed by T. F. Kassner, ANL. He then presented an .m l analysis of the data which included a strain-localization. parameter ' ' '
? based on axial restraint and circumferential temperature gradients I -
which correlated data determined over a wide range of degrees of restraint, temperature gradients, and heating rates.
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/ ' Data reported by A. A. Bauer, BCL, on the transient heating burst -
i j tests of irradiated cladding removed from the spent fuel of the -
/ H. B. riobinson plant were in excellent agreement with those reported by Chapman from the MRBT program, showing that the irradiation
- i- damage produced by a burnup of about 30,000 MWD /MTM was effectively a.
, anncale6 out by the time the burst temperature was reached (740*C was ~
ai, the lowest burst temperature yet observed in the program).
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,, Conducting an analysis of the transient heating burst data reported
' by Kassner, at ANL, with the inclusion of a limited amount of other data, P. G. Smerd, Combustion Engineering Inc. , concluded that burst strains and strain patterns are quite sensitive to many -
1 g factorst of the test, that the method of heating is the most important
?' g of 1the tests parameters, and that internal conduction heaters are the l
- most realistic for simulation of nuclear heated fuel rods.
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Experimental gap conductance measurements made at Halden in NRC l .
sponsorer!ctests were analyzed by R. E. Williford and C. R. Hann i N to permit calculation of circumferential temperature gradients of I
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/, 15-20*C t'ypically on the ID of fuel rod cladding for the case of eccentric fuel pellets during normal operation of a reactor.
, , {,' o , Williford reported also that the asymetric relocation of fuel L,/ fragments was'found to severely localize.the temperature differences
'4 of about 20*C to a circumferential sector of only a few degrees wide 3 (a few~ tenths of a mm in a 15x15 PWR rod).
!" J. A. Dearien'then showed that the computer code FRAP-T could be used to calculate typical circumferential temperature variations of 9
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I *r MAR 3 i B78 45*C at a peak clad temperature of about 1000*C in a BWR fuel rod at 160 seconds into a LOCA, that the ballooned section of one rod could cause the ballooning and burst of a neighboring rod to occur at another axial position, and that an axial temperature difference of only 5'C could cause localization and restriction of the balloon length. He also showed that FRAP-T could be used to accurately model the axial strain profiles observed in burst specimens heated by Joule heating (Hindle) and by an internal conduction heater (Chapman).
The distribution of peak cladding tenperatures observed in a simulated fuel bundle in a FLECHT tests was reported by L. Hochreiter, Westinghouse. Typically, the peak clad temperatures measured at a given elevation varied around any chosen rod from 5*F to as much
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i as 200*F (or greater) from one neighbor to another. In no case were the temperatures of the " surroundings" uniform to 50*F for any i
' rod reported. The temperature differences changed with time and the approach of the quenching front. Generally, the data showed that the uniformity of temperatures, both axially and circumferentially required to produce extended axial ballooning would not occur, provided that the FLECHT tests produce a reasonable simulation of .
the behavior of a nuclear fuel bundle during a LOCA.
The LOCA tests planned for the PBF were discussed by W. J. Quapp, EG&G. Single rod tests with " cold" flow control shrouds will be conducted to examine the behavior of nuclear heated fuel rods during
- blowdown and heatup phases of LWR LOCA's. Test objectives include the determination of the effects of axial and circumferential temperature gradients, cladding deformation patterns and gap gas -
flow response, the extent of the metal-water reaction, and the degree of oxygen embrittlement, and the productio'n of'in-pile data for comparison to the MRBT out-of-pile data.
The last presentation was made by S. A. Naff, EG&G, who described the NRC IFA-511 program planned for conduct in the Halden reactor to compare the response of Zircaloy fuel cladding for both nuclear -
and electrically (internal conduction) heated tests in the same test space.
The floor was opened for general discussion. After questions were answered as to the experimental and analytical work presented, F. Erbacher stated that it was also necessary to conduct an accurate simulation of the heat transfer conditions expected in a LOCA. There seemed to be unanimous support of this sentiment from the researchers of the' audience.
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MAR 31 1979 :
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i T. Healey pre::ented his summa'ry of the workshop, concluding that I i
both axial and circumferential temperature gradients must occur in'a nuclear rod during LOCA, and that they must be present in any realistic simulation.
While many of the participants were convinced that extended axial balloons would not occur in a LOCA, representatives from the UKAEA Springfields Laboratory and the UKNII thought it premature to rule it out. It was suggested that another workshop may be necessary.
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After expressing his appreciation of the efforts by the several -
speakers and of the attention of ths audience, the Chairman closed ,i .sm the workshop at 5:05 p.m. ,
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. L. picklesimer Fuel Behavior Research Branch ' (~
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Division of Reactor Safety Research
Enclosures:
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TENTATIVE WORKSHOP AGENDA -
NOVEMBER 11, 1977 SIMULATION OF NUCLEAR FUEL RODS IN LOCA Conference Room B National Bureau of Standards l Gaithersburg, MD !.
Chairman: M. L. Picklesimer, NRC 9:15 - 9:40 Introduction and Statement of the Problem M. L. Picklesimer, NRC 9:40 - 10:00 Extended Axial Ballooning in Zircaloy E. D. Hindle &
Cladding - Joule Heating D. O. Pickman, SNPDL/UKAEA lE 10:00 - 10:20 Single and Multirod Tests, Internal W. A. Fiveland &
Radiant Heating A. L. Lowe, B&W Analysis of Axial Ballooning Behavior of T.Healey,B.D. Clay,(CEGB!
Directly Heated Zircaloy Tubes & R. B. Duffey (EPRI) 10:20 - 10:40 C0FFEE BREAK }
10:40 - 11:00 Transient Burst Tests and Circumferential D. L. Burman, Westinghouse Temperature Gradients, External Radiant ~'
Heating 11:00 - 11:20 Single and Multirod Tests, Transient and Steady R. H.. Chapman, ORNL State, Internal Conduction Heating 11:20 - 11:40 Single and Multirod Tests Transient and Steady F. Erbacher.
State, Internal Conduction Heating PNS/GfK, Karlsruhe 11:40 - 12:10 Effects of Temperature Gradients in Transient T. F. Kassner, ANL Heating Burst Testing, Joule Heating 12:10 - 12:30 Transient Heating Burst Tests on Irradiated A. A. Bauer, BCL Cladding, Internal Conduction Heating 12:30 - 1:30 LUNCH ,
1:30 - 1:50 Factors Influencing Strain Behavior in P. G. Smerd Simulated LOCA Transients Combustion Engineering I 1:50 - 2:10 Effects of Pellet Eccentricities in Halden R. E. 'W1111 ford &
Gap Conductance Tests . C. R. Hann, BNWL ,
I 2:10 - 2:30 Effects of Manufacturing Tolerances on A. L. Lowe & B. Bingham j Surface Temperature of Neighboring Babcock & Wilcox l Pellets During LOCA
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Agenda - SIMULATION OF NUCLEAR FUEL RODS IN LOCA ~
2:30 - 2:50 Distribution of. Peak Cladding Temperatures J. A.
Dearien,
EG&G in a Bundle During LOCA as Calculated by FRAP -
2:50 - 3:10 Distribution of Peak Clad'ing d Temperatures L. E. Hochreiter, ,
in FLECHT Tests Westinghouse !
3:10 - 3:30 C0FFEE BREAK 3:30 - 3:50 Single and Multirod Nuclear Tests in PBF W. J. Quapp, EG&G t 3:50 - 4:10 A Halden Experiment to Compare Nuclear and S. Naff EG8G Electrically Heated Rods During Reflood i
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Enclosure B Roster of Attendees Name Organization j M. L. Picklesimer FBRB/NRC J. D. Harvie AECB Canada J. G. Waddington AECB Canada Leo Sepold GfK Karlsruhe/INEL Idaho J. B. Sayers UKAEA, Harwell C. C. Baylis BNFL Springfields Works, UK R. H. Chapman ORNL R. A. Shaw , SNL Springfields UKAEA D. O. Pickman SNL Springfields UKAEA K. Suzaki Toshiba Electric Co., Ltd. ~;
Tim Healey CEGB Berkeley Nuc. Labs., UK T. N. Rutherford NII(H+S.E.),UK D. R. M. Fryer NII (H + S.E.), UK R. N. H. McMillan UKAEA, SRD.
G. M. Jordan UKAEA(SRD)
J. Randles JRC-Ispra Paul Shewmon NRC-ACRS Adrian Roberts EPRI F. J. Feyers UKAEA, Winfrith
- R. I. Hawes UKAEA, Winfrith, UK John A. Dearien EG&G Idaho Carlo Mancini CNEN, Rome, Italy Dale E. Fitzsimmons Battelle Northwest /PNL A. A. Bauer -
Battelle-Columbus W. J. Quapp EG&G Idaho D. L. Burman Westinghouse T. F. Kassner ANL A. L. Lowe, Jr. B&W-NPGD W. A. Fiveland B&W-A.R.C., Research J. L. Crowley
- ORNL E. L. Courtright PNL P. J. Pankaskie BNW/PNL f C. L. Mohr BNW/PNL :!
J. A. Christensen. BNW/PNL~ !!
R. E. Williford 8 -
BNW/PNL 3
- E. F. Jageler Combustion Engineering Richard Oehlberg EPRI Perlingi Fien -
NUCLITAL [
P. L. Hedrick PNL ~
M. J. Arnold CEGB/UK (.
R. S. Hoverd GEC/UK K. T. Routledge NPC/UK J. G. Collies UKAEA/UK -
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Roster of Attendees 2 .
Name Organization l W. G. Lussie , EG&G Idaho, Inc.
A. W. L. Segel AECL, Chalk River R. Dimenza c/o AECL, Chalk River S. Finzi J.R.C. EURATOM.ISPRA(Varese-Italy)
A. Pedretti CNEN, Italy i J. L. Ricard . A.E.C.B., Ottawa i D. J. Merrett " NPC/UK i Michio Ishikawa JAERI l Paul Boehnert NRC/ACRS 6 .. ,
J. O. Cermak Westinghouse !-
L. E. Hochreiter Westingbouse '
Granville Sewell ORNL /
F. D. Coffman USNRC/ DOR (. 1 R. V. Belluz T. Kobori AECL, Power Projects PNC, Japan j 7-1 4
R. C. Hagar ORNL(PWR-BDHT)
L. J. Ott ORNL (PWR-BDHT)
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R. E. Textor -
Union Crabide Corp., Oak Ridge j.
R. A. Hedrick ORNL(PWR-BDHT) ,
W. L. Riebold C.E.C.-J.R.C. Ispra/ Italy F E. Dluzniewski GRS-F.R. Germany .e' ~
A. J. Hedemann GKSS-FRG 1 T. A. Doyle EURATOM-JRC, Ispra, Italy N F. J. Erbacher GfK-F.R. Germany .
F. Wunderlich KWU-F.R. Germany -4:
P. G. Smerd Combustion Engineering 3.bZ D. S. Rowe .
Engineering Consultant '
L. H. Vons -
E.C.N. - Petten - Holland .x ~
P.. S. Check NRC/NRR '
D. A. Powers NRC/NRR R. O. Meyer NRC/NRR ,
Russ Ball BAW - Lynchburg Manfred Fischer GfK - Karlsruhe Rom Duffey EPRI H. Koponen IRP, Finland '
B. Tolley CEC Brussels . ;
G. P. Marino NRC/RSR l L. Thompson NRC/NRR !
,i M. Tokar .
NRC/NRR S. A. Naff EG&G - LOFT J. L. Butragueno NRC/ Standards :
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