ML20083H228
| ML20083H228 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 11/09/1983 |
| From: | GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER |
| To: | |
| Shared Package | |
| ML20083H225 | List: |
| References | |
| 906968, 906968-RA, NUDOCS 8401130089 | |
| Download: ML20083H228 (33) | |
Text
{{#Wiki_filter:' l G A 1485 (REV.1%C2) ROLL 1457 A GA Techn' ologies Inc. ISSdE
SUMMARY
TITLE METALL0 GRAPHIC EXAMINATION OF A FUEL R0D FROM OR&D APPROVAL LEVEL 2 8 SEGMENT 2 FSV FUEL ELEMENT 1-2415 O S GN t 4 DISCIPLINE SYSTEM 00C. TYPE PROJECT ISSUE NOJLTR. l DOCUMENT NO. N 18 RTE 1900 [ 906968 A 5 QUALITY ASSURANCE LEVEL SAFETY CLASSIFICATION SEISMIC CATEGORY ELECTRICAL CLASSIFICATION QAL-I SC-2 CAT-I N/A APPROVAL ISSUE PREP ^ i ISSUE DATE D ESCRIPTION/ BY FUNDING APPLICABLE EN lh E,ERING QA PROJECT PROJECT CWBS NO.
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Stank d DOJMD a in/F/s; D.Alberste 9 k CONTINUE ON G A FORM 14851 N EXT INDENTU RED DOCUMENTS P.O.N-4567 8401130089 840103 PDR ADOCK 05000267 P PDR REV l SH 9 r REV SH 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 4
- REV SH 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 PAGE 1 0F 33
r GA Technologies inc, GA-1484 (REV.10/82)
-> TITLE: METALLOG2AFRIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 luue A TABLE OF CONTENTS e
f.agg a
- 1. INTRODU CTI ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
- 2. BLOCK (S/N: 2-1415) BACKGROUND.............................. 4 2.1 Element Description..................................... 4 2.2 Element History......................................... 5
- 3. METALL0 GRAPHY............................................. .. 6 "a
E 4. METALL0 GRAPHIC EIAMINATION RESULTS........................... 6 5 m
- 5.
SUMMARY
AND CON CLUS ION S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 t 4
- 6. REFEREN CES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 h
T LIST OF TABLIS f E 1. Comparison of Blocks with Cracke d Webs. . . . . . . . . . . . . . . . . . . . . . . 12 5
, $ 2. Nominal Preirradiation Fuel Rod Attributes for FSV Segment 2 Fue l El em e nt 1-2 415 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
]5 e
E 3. Nominal Fissile Fuel Particle Attributes for FSV Fuel Element S/N: 1-2415................................................. 14 3
.e 6 4. Nominal Fertile Fuel Particle Attributes for FSV Fuel Element j S/N: 1-2415................................................. 15 8 16
'ii 5. Fissile Particle Meta 11ographic Examination Results..........
E sr:
- 6. Fertile Particle Meta 11ographic Examination Results.......... 17 LIST OF FIGURES
- 1. FSV block face identification................................ 18
- 2. S ta nda rd FSV f uel el eme nt 1-2 415 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
- 3. Core location of FSV fuel element 1-2415..................... 20
- 4. Location of fuel rod use d in meta 11ography. . . . . . . . . . . . . . . . . . . 21
- 5. Composite photograph s of fuel rod sta ck 308. . . . . . . . . . . . . . . . . . 22
- 6. Photomicrographs representative of m:trix phase of irradiated rod 13 from stack 308. The time , erage fuel temperature was
- approximately 7650C at an average tast fluence of 1.6 x 1025
-#* 25 n / m2 ( E > 2 9 fJ ) HTG R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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-> TITLE: NETAI10 GRAPHIC EZAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Issue A
- 7. Representative photomicrographs of composite of radial cross
, section of fuel rod from FSV element 1-2415.................. 26
- 8. Photomicrographs of fissile (a,b) and fertile (c) particles.. 29
- 9. Photomicrographs of fissile particle (Th,U)C2 showing fuel dispersion................................................... 30
- 10. Photomicrographs showing sic-fission product interaction in the fissile (a) and fertile (b ) par ticles . . . . . . . . . . . . . . . . . . . 31
- 11. Photomicrograph of an as-manufactured defective particle in an j irradiated fuel rod.......................................... 32 E
- 12. Photomicrographs showing in pile coating failures............ 33 3
2 c
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.E C
E 2 8 b
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+ METALL0 GRAPHIC EIANINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. luue
. 906968 A
- 1. INTRODUCIION During the core segment 2 surveillance in April of 1982 at the Fort St.
Vrain (FSV) reactor site, fif ty-four fuel and reflector elements were metro-logically and visually inspected. The metrological inspections were carried out using the metrology robot described in Reference 1. The visual inspec-tions employed four remotely controlled television cameras equipped with pan-tilt units and zoom lenses. All element surfaces were thoroughly inspected, i and recorded on videotape and on 35 mm photographic film. A hairline axial E g crack was observed extending the entire block length in the center of face B
$ (see Figure 1) of the element S/N: 1-2415 (core location 08.05.F.06) . Later iG c inspection of the videotape s and photographs revealed a second element S/N:
f 1-0172 with a suspected similar crack in face B, later confirmed by examina-tion in the GA Hot Cell (Ref. 2). This block was located one layer lower, j directly beneath element S/N: 1-2415 at core location 08.05.F.07.
?
A
] To characterize better the cracks and determine why they occurred, the $ two blocks with cracked webs, along with three other blocks of potential in- .2 8 terest, were shipped to the GA Technologies, Inc. hot cell for visual and de- .e E structive examinations. The visual examinations were completed and reported C "; in Reference 2. Element S/N: 1-2415 was selected for postirradiation de-C structive examination as part of the US DOE - funded HIUR Technology Program $ (Ref. 3). This block was selected because it exhibited the wider crack, and it experienced larger fast fluence and metrological changes (see Table 1).
Fuel rod metallography, which was not part of the DOE program, was funded by Public Service of Colorado to meet its commitments to NRC regarding fuel sur-veillance (Ref. 4). This report covers the fuel metallography portion of the postirradation dcstructive examination.
- 2. BLOCK (S/N: 1-2415) BACKGROUND 2.1 Element Description Element S/N: 1-2415 consisted of a standard H-327 graphite fuel body
+ having 210 fuel holes, 6 burnable poison holes, and 108 coolant channels (see Page 4
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, TITLE: METALL0 GRAPHIC EXAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Issue A Figure 2). There was no lumped barnable poison installed in the element. The ~
element contained 3132 fuel rods consisting of (Th,U)C2 1RISO(*) fissile par-ticles and ThC2 IRISO fertile particles bonde d together in a carbcnaceous matrix. These TRISO coated particles were formed into fuel rods from fuel rod batch G16N-10167, blend 1. The nominal preirradiation dimensions of the fuel i rods were 12.5 mm (0.49 in.) in diameter and 49.3 mm (1.94 in.) in length. Fuel rod and fissile and fertile particle nominal attributes are given in Tables 2, 3, and 4, respectively. E g 2.2 Element History E E { The element was irradiated in region 8, column 5, core layer 6 (third f layer frce top of the active core). Figure 3 shows this core location (08.05.
- F.06). This element was part of the initial core (segment 2). Prior to j February 1,1979, when the reactor was shutdown for the first refueling, the
, j initial core had operated for 174 effective full power days (EFPD). Cycle 2 j operation began on May 26, 1979 and was completed on May 13, 1981 after having accumulated a total of 189 EFPD. Thus, when element S/N: 1-2415 was removed l from the core, it had accumulated a total of 363 EFPD. The average fast
-8 h fluence (b) accumulated by the element was approximately 1.55 x 10 25 n/m2 (E >
l 'f 29 fJ)HIGR with a peak of about 1.79 x 1025 n/m2 . The calculated time and j volume-averaged graphite temperature was 6500C, with a peak graphite tempera-I h ture of 7000C(c). The calculated time average fuel temperature was 7650C. (c) (a)In the TRISO particle design, a layer of sic is sandwiched between two layers of high-density pyrolytic carbon, which provides a composite pressure vessel to retain gaseous fission products. The sic coating also provides a barrier against the dif fusion of metallic fission products and increases the mechanical and dimensional stability of the particle during irradiation. An inner low-density, or buff er, coating adj acent to the fuel kernel provide s a void volume to accommodate fission gases and kernel swelling and, in addition, attenuates fission product recoils. (b) Fast neutron fluence was obtained from the GATT code fuel accountability analyses f or cycles 1 and 2. The fast neutron fuer.ce was volume averaged (Ref. 1). (c)These temperatures were obtained from SURVEY code calculations which use
- input from GAUGE code depletion analyses (Ref.1) .
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, TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Issue A
- 3. METALLOGRAPHY The metallographic examination was performed in accordance with the procedure outlined in Reference 5. Irradiated fuel rod 13 from fuel stack 308 was subj ected to metallographic examination because it was expected to have a high temperature history relative to the fuel elsewhere in the element and, thus, would provide an indication of thermal effects in the fuel earlier than fuel rods from lower temperature portions of the element. This fuel rod, which was one rod length above the bottom of the fuel hole, came from the g axial location in the block where the power peaked (Ref. 6). Fuel stack 308 was chosen because it was located under the dowel pin of f ace B adj acent to
$ the cracked web. Figure 4 shows the location of fuel stack 308 in reference f to the cracked web. In general, the appearance of the fuel rods f rom stack A little chip-a f 308 was good, with no evidence of fuel rod-block interaction.
ping at the ends of the rods and some debonding of particles from the rod were
$ observed (see Fig. 5). Rods which were chipped and slightly debonded on the 2
'y ends appeared similar to the preirradiated rods and are not believed to have
$ been damaged during operation or by the extraction of the stack from the fuel block. This conclusion is further supported by the low pushout force (I7lbs)
.e
-5 required to remove the stack from the fuel element. Also, the small amount of t .-
iC debris collected from the emptied block is indicative of a lack of fuel rod-j block interaction. E z Rod 13 was mounted in resin, ground, and polished in the metallographic hot cell. Prior to examination, all polished sections were passivated with a 50/50 solution of HNO 3 and H2 O to decrease the rate of hydrolysis of the ThC2 kernels. The entire polished surf ace of the rod was then examined. i
- 4. METALL0 GRAPHIC EIAMINATION RESULTS l
The fuel rod matrix appeared to be in good condition. Minor cracking of the matrix end caps similar to the cracking observed in segment I and the acceptable preirradiated rods, was observed. The microstructure of the matrix 0 Page
G A-1484 (REV.10/82)
-> TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 issue g after irradiation is shown in Figure 6. The irradiated microstructure was f
similar to the microstructure observed for FSV fuel rods irradiated in the FSV fuel proof capsule F-30 (Ref. 7) . The measured macroporosity for rod 13 was 17.5%. This value is within the (14-29%) range of macroporosities observed for fuel rods from capsule F-30 (Ref. 7) . An example of a radial cross sec-tion showing the sacroporosity in the matrix is shown in Figure 7. The results of the metallographic examination of fuel rod 13 from fuel stack 308 are presented in Tables 5 and 6. The irradiation performance of the f
$ fissile and fertile TRISO coated particles was satisfactory as evidenced by the moderate ccating f ailures and good thermal performance. The microstruc-j tures of typical particles after being exposed to a peak fast neutron fluence f of approximately 1.79 x 1025 n/m2 (E > 29 fJ)HIUR and a time-averaged fuel temperature of 7650C, are shown in Figure 8. A total of 231 fissile and 184 i fertile particles were examinod.
A Fuel dispersion was observed in 75% of the fissile and 5% of the f er-3
! tile particles. An ext.mple of fuel dispersion is shown in Fig. 9. Fuel dis-persion can be caused by chlorine which can diffuse through a permeable IPyC
._[
j into the buffer during the sic coating operation. Production records indicate that this fuel had relatively low density IPyC and a tendency to exhibit fuel 3 dispersion. e . The primary purpose of the metallography was to examine the fuel for thermal eff ects. In this regard the chemical behavior of the TRISO particle was acceptable. Kernel migration was not observed. Interaction of the sic coating with fission products was observed in both particle types. Figure 10 shows examples of the sic interaction. SIC interaction was observed in 3.9% of the (Th,U)C2 Particles and 3.3% of the ThC2 Particles. The reaction pene-trated about 5 pm into the sic layer for both particles types. This kind of interaction is expected in carbide fuel, where rare earth fission products are released from the kernel and react with the sic (Ref. 8) . Page 7
- - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . 1
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-b TITLE: METALL0 GRAPHIC EZAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No.
906968 he A However, the observed depth of reaction (~J pr) was larger than the <1 pm expected depth based on the time-temperature history of the fuel. This rapid penetration rate may have been associated with fuel dispersion caused by chlorine trapped in the buffer layer during the sic coating operation, as discussed above, and/or a higher operating temperature than the average cal-culated for the fuel element. Penetration depths on the order of 10 to 15 pm might lead to some volatile fission product metal release, but total coating failure and fission gas release would not increase (Ref. 8). The penetration
@ depth measured for these particles is significantly less than these values.
Since fuel dispersion in the fuel which will reside in the core for up to six
= cycles is much less than dispersion in these fuel particles, it is not ex-g j pected that fission product-sic interaction will have an impact on core per-en j fo.mance. However, this phenomenon will be monitored in future FSV fuel sur-
$ veillance so that any influence on core performance can be properly assessed.
.lE a
. In the course of metallography the mechanical condition of the costing 3 can be observed, but conclusions from these data are difficult to draw because coating failure can be caused during manufacture and during the grinding and 8 polishing procedure in connection with making a metallographic mount. There a
E was evidence that some of the coating failures can be attributed to as-mann-factured f ailures which occurred during coating or rod f abrication. This con-j clusion is supported by the appearance of failed particles. An example of S this type of failed particle is shown in Figure 11 where the particle had the appearance of having been crushed and fuel rod matrix was pressed into the coating cracks at the time of manuf acture. In this case as-manufactured fail-ure rather than in pile failure was indicated. However, unlike the metallo-graphic results of Segment 1 (Ref. 9), there was partial coating f ailure which may have occurred in pile as seen in Figure 12. Irradiation induced shrinkage of the pyrocarbon was apparently enhanced by the additional exposure of cycle 2 and both IPyC and OPyC f ailures were observed as expected from accelerated capsule results (Ref. 7). For purposes of comparing with prior work, counts e of observed failed individual coatings are reported in Tables 5 and 6. These Page g
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+ METALL0 GRAPHIC EIANINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 .
Doc 9 ment No. 90C968 I" A values should be considered upper limits. The total coating f ailure with re-suiting gas release can be expected to he .very low because circulating gas activity has remained consistently low and indicates virtually no particle failure. However, as noted in Tables 5 ana 6, the actual number of total coating f ailures was not determined due to hydrolysit1 of the kernels in the fsel rod mount. t
,, 5.
SUMMARY
AND CONCLUSIONS R e c j The performance of the fuel was _ acceptable. Specific observations and conclusions are summarized as follows: 5 f g
- 1. Fuel rod 13 from stack 308 was in good condition although minor cracking in the matrix end caps and soma debonding of particles from
$ the rod surface were observed. .
2 S A 2. There was no fuel rod - bloik interaction as evidenced by the visual examination of the rode, by the small pushout force of the stack, and _$ by the small amount of debris collected from the emptied block. 4 '
.E I? 3. The measured macroporosity for rod 13 was 17.5%, which was within ths .9 j (14-29%) range of macroporosites observad for fuel rods from capsule
- F-30.
- 4. A total of 231 fissile and 184 fertile particles from rod 13 were examined. For the (Th,U)C2 and ThC2 particles, respectively, the OPyC coating f ailure was 0.4% and 7.6%, and the sic coating f ailure was 0.9%
and 3.8%. However, these coating failures should be considered the upper limits since coating failures can be caused during manuf acture and during the grinding and polishing procedure, as well as during irradiation. Y Page 9
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-> TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 F%V FUEL ELEMENT 1-2415 Document No. 906968 issue A
- 5. The chemical behavior of the particles was acceptable. There was no kernel migratics observed. Howev er, there was evidence of fission product interaction with the sic coating. 3.9% of the fissile parti-clos and 3.2% of the fertile particles showed fission product -
sic interaction with a penetration depth of ~5 pm, which was higher than the expected value of <1 pm. The phenomens may have been caused by fuel dispersion resulting from chlorine trapped in the buffer layer during the sic coating and/or by higher operating temperatures than the
) average calculated for the element.
- 6. Fuel dispersion, which is attributed to chlorine diffusing through a j low density IPyC into the buffer layer during the sic coating proce as, 52 "
j and IPyC debonding were observed in some of the TRISO (Th,U)C2 and TtC2
$ particles. Fuel dispersion and IPyC debonding did not detrimentally affect the. performance of the particles.
2 3 6. REFERENCES 5 2
- 1. SAURWEIN, J. J., Nondestructive Examination of 54 Fuel and Reflector
- Elements from Fort St. Vrain Core Segment 2, GA-A16829, October
.5 .1g g 1982, PSC transmittal to NRC P-83196, June 2,1983.
E s 2 2. KETTERER, J. W., Visual Examination Results of Segment 2 FSV Fuel Elements 1-2415, 1-0172, 2-2693, 1-0108 and 5-0801, Document No. 906577, Issue B, April 4,1983, PSC transmittal to NRC P-83196, June 2, 1983.
- 3. McCORD, F., Test procedure for the Destructive Examination of Fort St. Vrain Fuel Element 1-2415, Document No. 906770, Fsbruary 25, 1983.
- 4. LEE, O. R. (PSC) letter to John Collins (NRC), Commitment to FSV Fuel Surveillance , P-83058, February 10, 1983.
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+ METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. Issue
. 5. SCHEFFEL, W. J., Hot Cell Meta 11ographic Examination of Irradiated Fuel Rods, Document No. 904199, Issue A, October 8, 1979.
- 6. Public Service Company of Colorado Fort St. Vrain Nuclear Generating Station Updated Final Saf ety Analysis Report, Docket No. 50-267, July 22,1982 (Fig. 3.5-10) .
- 7. SCOTI, C. B. and D. P. HARMON, Postirradiation Examination of Cap-4 E sale F-30, Document No. GA-A13208, April 1, 1975. .
.o j 8. HIER Fuel Technology Program Semiannual Report for the Period Ending September 30, 1982, DOE Report GA-A16919, November 1982.
m E
. 5 g 9. SAURWEIN, J. J., C. M. MILLBt and C. A. YOUNG, Postirradiation i Examination and Evaluation of Fort St. Vrain Fuel Element 1-0743,
- 2
,y GA-A16258, May 1981.
E s
- 10. HACKNEY, Rachel, Fort St. Vrain Cycle 2 Core Performance, GAC-
,y 16743, April, 1982.
E
.5 E .e 3
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-> TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Issue A Table 1 COMPARISON OF BLOCKS WITH CRACKED TEBS Item S/N: 1-2415 S/N: 1-0172 1
l l Element Type Fuel Fuel Core Location 08.05.F.06 08.05.F.07 Top Crack Width (mm) (Ref. 2) 0.20-0.25 0.13-0.15 Botton Crack Width (mm) (ref. 2) 0.28-0.30 0.05-0.08 Temperature (OC)(*) 650 700
.g Fluence (x 1025 n/m2 )(a) 1.55 1.28 !
g Meas.. Axial Strain (%)(b) -0.337 1 0.027 -0.163 + 0.010 g Meas. Radial Strain (%)(b)i i la lo -0.257 1 0.027 -0.089 1 0.019 2 Meas. Bow (mm) 0.43 0.28 g Gross y Activity (R/h) at 91.5 cm(c) 458 385 2 g (a) Temperature were obtained from SURVEY code calcalatior.s based on 5 the GAUGE code depletion analysis of FSV Cycles 1 and 2. Fast E neutron fluences were obtained from the GATT code depletion ans-
$ lysis of Cycles 1 and 2. Temperatures are for the graphite block
'$ time and volume averaged. The temperature uncertainty (la) is 3 estimated at 10% of the difference between the block temperature
. j and the (~33500, time averaged) gas-inlet temperature. The fast
.E neutron fluences (E > 29 fJ)HTGR are volume averaged. The uncer-l tainty in the f ast fluence is ?,10% (la) .
.g (b) Measured v alt.e s came from the results of the metrology robot.
3 (Ref. 1). Azial strains are element averages. Bow is at element 3 midplane. Radial strains are element-averaged strains at the top e of the blocks.
} (c) Measured during nonde structiv e ext.;is tion (see Ref. 1) with a g Reuter-3 toke s, Model RS-C4-1606-203, gamma ionization chamber.
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@ METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGNENT 2 FSV FUEL ELEMENT 1-2415 Document No.
906968 Issue A Table 2
, NOMINAL PREIRRADIATION FUEL ROD ATIRIBITIES FOR FSV SEGMENT 2 FUEL ELEMENT 1-2415 Fuel blend type: CR 16N-10167 Blend 1 Pronerty Acceptance Value i Preirradiation fission gas release, 13 x 10-5 E Kr-85m at 11000C:
c 2 j Heavy metal loadings j U: 0.15 g/ rod 8' Th: 4.13 g/ rod 5 e These requirements are for the average of all fuel rods in
.E the core.
5
, $ Thorium contamination: 18x10-4 5
i Impurities (ppm) 3 B: 15 x Fe: 6 S: <1500 1200 E 1 Ti: ~ <50
$ V: 350 j Residual hydrogen: I200 y Residual ash: 13000 H2C:
C1. Firing temperature (OC): 1800
-denostes no available data f
e a
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-> TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Ime A Table 3
. NOMINAL FISSILE Ft:EL PARTICLE ATIRIBUIES FOR-FSV FUEL ELEMENT S/N: 1-2415 Pronerty Accentance Value Kernel type: (Th, U) C2 Th/U mean ratio: 3.60 _ * ,
$ Kernel A nominal diameter: 100 to 175 pm
[g Kernel B nominal diameter: Particle type: 175 to 275 pa TRISO a f C Meas. Coating Parameters E" Mean thickness: e Buffer: 25-75 pm
.E! IPyC: 13-35 pm*
3 Sic: 15-35 pm
. 5 OPyC (Fissile A) >20 pm j OPyC (Fissile B) 7 pm
_25 C 5 Mean density:
~o .$ Buffer: 0.75-1.40 Mg/m3 E IPyC: 1.70-2.00 Mg/m3 3 sic: >3.16 Mg/m3 ,8 OPyC: 1.60-2.00 Mg/m3 5
j Mean IPyC OPIAF: <1 Mean OPyc OPIAF: I_1.25
.30
- Combined thickness of seal plus inner-iso coatings.
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-> E:
METALL0 GRAPHIC EIANINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 9069C8 Ime A Table 4 NOMINAL FERTILE FUEL PARTICLE ATIRIBUTES FOR FSV FUEL ELEMENT S/N: 1-2415 Pronerty Accentance Value Kernel type: ThC2 Particle type IRISO Kernel A nominal diameter: 300 to 410 pm
. Kernel B nominal diameter: 410 to 500 pm R
E Mean Coating Parameters 7 Mean thickness: A g Buffer: ?$-75 m { IPyC: 13-40*
, 5 Sic: 15-35 pa e OPyC (A) >20 pm j OPyC (B) 230pm Mean density:
u i Butfer: 0.75-1.40 Mg/m3 5 IPyC: 1.70-2.00 Mg/m3
-8 sic: 13.16 Mg/m3 g
. OPyC: 1.60-2.00 Mg/m3
'3 Mean IPyC OFIAF: <1
.[ Mean OPyC OPIAF: I_1.25
.30 3
- Combined thickness of seal plus inner-iso coatings.
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+ TITLE: METALL0 GRAPHIC EXAMINATION OF A FUEL ROD FROM SEGENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Ime A Table 5
. FISSILE PARTICLE METALL0 GRAPHIC EIAMINATION RESULTS Pronerty _Xalgg Time average fuel temperature (OC) 765(a) Fast fluence z 1025 n/m2 (E > 29 fJ)HitiR 1,79(b) Fissile FINA (%) 8.35(c) l Number of particles examined 231 i S Buffer fallare (%)(e) 3.0 E IPyC f allare (%)(*) 3.0 5 sic failure (%)(*) 0.9 S OPyC f allure (%)(*) 0.4 Is Total coating f ailure (%) N.D.(d) t Dispersion in buffer (%) 74.9 y Dispersion in IPyC (%) 1.3 E Debonding in IPyC (%) 42.9 U SIC attack (%) 3.9 53 Flawed sic coating (%) 0.4 2 Ci j (a)Taken' from the SURVEY code, axial point 5, local
; points 4 and 5 (fuel temperature time-averaged).
E (b) Data from Ref. (1). f (c) Data from Ref.10.
.; (d)Not determined because the initial fuel rod mount K E hydrolyzed before any meaningful data could be gathered for the total coating failure. $ (*)For each particle with coating failure, one or i more intact coatings remained on the particle even j though one coating was observed failed.
e
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GA Technologies inc, GA-1484 (REV.10/82)
-> TITLE: NETALLOGRAPHIC EIANINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Issue A Table 6 FERTILE PARTICLE METALL0 GRAPHIC EIANINATION RESULTS Pronerty Value Time average fuel temperature (OC) 765(*)
Fast fluence z 1025 n/m2 (E > 29 fJ)HTUR 1.79(b) Fertile FINA (%) 0.61(c) Number of particles (zamined 1 84 i Buffer failure (%)(e) 18.5 E IPyC f allure (%)(*) 10.3 5 sic failure (%)(*) 3.8 5 OPyC f milure (%)(*) 7.6
$ Total coating f ailure (%) N.D.(d) i Dispersion in buffer (%) 5.4
$ Dispersion in IPyC (%) 1.6 E Debonding in IPyC (%) 12.0 g sic attack (%) 3.3 2 Flaved sic coating (%) 6.5 c
5 f (*)Taken from the SURVEY code, axial point 5, local
; (b) Data pointsfrost 4 and 5 (fuel E Ref. (1). temperature time-averaged) .
$ (c) Data from Ref.10.
." (d)Not determined because the initial fuel rod mount 5 hydrolyzed before any meaningful data could be E gathered for the total coating failure.
$ (*)For each particle with coating failure, one or j more intact coatings remained on the particle even g though one coating was observed failed.
l Page 17
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G A-1484 (R EV.10/82) TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL I, ELEMENT 1-2415 Document No. 906968 issue A
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+
Page 19
GA Technologies inc, GA-1484 (REV.10/82)
) TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Issue A
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' FUEL ELEMENT 12415 REGION 8, COLUMN 5, CORE 1.AYER 6 (ACTIVE CO RE LAYER 3)
Fig. 3 Core location of FSV fuel element 1-2415 Page 20
GA Technologies inc, GA-1484 (REV.10/82) 4 TITLE: METALL0 GRAPHIC EXAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 luue A . I l
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~ COOLANT HOLE 0.625 OIA (102)
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G A-1484 (R EV.10/82)
+ TITLE: METALLOGR."PHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL FI. M NT 1-2415 Document No. 906968 Issue A ~
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Page 22
GA Technologi s Inc. G A-1484 (REV.10/82)
, TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 lssue A ,
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Fig. 5 Composite photographs of fuel rod stack 308 (con't) Page 23
G A-1484 (REV.10/82)
-> TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL j FIFMFNT 1-2415 Document No. 906968 Issue g j
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G A-1484 (REV.10/82) } + TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 5 Document No. 906968 luue A i ' N * = t 0
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F Page
- 26
G A-1484 (REV.10/82)
, TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2413 Document No. 906968 Issue A -
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j Fig. 7 Representative photomicrographs of composite of radial cross section of y (con't) fuel rod from FSV element 1-2415 (middle of rod)
+
Page 27
G A-1484 (R EV.10/82)
., TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL ELEMENT 1-2415 Document No. 906968 Issue A -
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j o ' l, gj _ bO h E Fig. 7 Representative photomicrographs of composite of radial cross section of (con't) fuel rod from FSV element 1-2415 (right side of rod) Page 28
Doc. #906968/A
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Doc. #906968/A
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20 pm 6 Fig. 9 Photomicrographs of fissile particle (Th,U)C2 showing fuel dispersion. Note the dense phase in the buffer coatings and the low-density IPyC coating. Page 30
G A-1484 (REV.10/82)
+ TITLE: METALL0 GRAPHIC FlAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL I!LEMENT 1-2415 Document No. 906968 Issue A 1
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'20 pm Fig. 10 Photomicrographs showing sic-fission product interaction in the ffssile (a) and fertile (b) particles Page 33
GA Technologies Inc. G A-1484 (REV.10/82)
+ TITLE: METALL0 GRAPHIC EIAMINATION OF A FUEL ROD FROM SEGMENT 2 FSV FUEL FLRWRNT 1-2415 Document No. 906968 Issue A w 1
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5 2 s Page 32
Doc. #906968/A -l 1 '4-Qjt ,
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_ h th :-w n m 330 pm Fig. 12 Photomicrographs showing in-pile coating failures. (a) and (b) show IPyC failures in the fertile and fissile particles, respectively. (c) Shows
- examples of OPyC and IPyC failures in the fertile particle and OPyC failure in the fissile particle. l Page 33 of 33 ,
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