ML25197A096
| ML25197A096 | |
| Person / Time | |
|---|---|
| Issue date: | 02/12/1974 |
| From: | Stratton W Advisory Committee on Reactor Safeguards |
| To: | Ray D NRC/Chairman |
| References | |
| Download: ML25197A096 (1) | |
Text
. ADVISORY COMMITTEE ON REACTOR SAFEGUARDS UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON, D.C. 20S45 February 12, 1974 F.onorable Dhy Iee Ray Chairman
- u. s. Atanic Ener~z camdssion Washington, D. c. 20545
Subject:
REPORT ON GENERAL ELECTRIC 8X8 FtJEL DESIQl EOR REIDAD USE
Dear Dr. Pay:
At its 166-tt"l meeting, February 7-9, 1974, the Advisory Ccmni.ttee on Reactor Safegua:cds carpleted a generic review of the design and ex-pected performance of General Electric 8x8 fuel bundles to be aT4?loyecl in partial and full core reloads in boiling water react;ors. 'lhese topics were discussed at the 165th ACRS meeting on January 10-12, 1974, and at Subcarmittee neetings in Washington, D. c., on Janua:cy 8, 1974, and in Denver, C.olorado, on January 24, 1974. During its review the carmittee had the benefit of discussions with reoresentatives of the General Electric Conpany, the AEC Regul.ato:cy Staff, and of the docu-ments listed below.
The General Electric 8x8 fuel assanbly consists of 63 fuel rods plus one unfueled, watez-filled, spacer-capture rod in a square 8x8 bundle array within a square channel box. 'lhe design of the fuel rods and fuel rod bundle in the 8x8 reload fuel assanbly is, except far differ-ences in the length of the fuel and gas plenum, the same ~ in the 8x8 fuel asse:r.bly used in the B!;\7R/6 boiling water reactor concept referred to in the camtl.ttee's report of Septem::>er 21, 1972. The 8x8 fuel bundles are interchangeable in General Electric boiling water reactors
- with the previously used 7x7 bundles.
In general, the thennal nargins to fuel d.r.lage design bases are greater for 8x8 fuel than for 7x7 fuel.
The design value of the linear heat ce..11.eration rate for normal o-oerati.on 1s 13.. 4 ~~r/ft:. for 8x8 fuel and 17.5 to 18.5 kw/ft for 7x7 fuel: specific power is slightly greater for the 8:x8 fuel than for the 7x7 fuel. The General Electric c.orrpany believes t.lie lower lL--iear heat generation rate and slightly great.er ratio of clad thickness to rod diameter should result in fewer failures in 8x8 fuel than in 7x7 fuel. Although the hydraulic resistance of 8x8 bundles is slightly great.er than that of 7x7 bundles, the themal-hydraulic per-fornance of oores either partially or fully loaded with 8x8 assemblies is not degraded relative to cores loaded with 7x7 assemblies.
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Honorable Dixy Lee Ray February 12, 1974 Since the U-235 enrichments for the :inlividual fuel rods, the nurrber and distribution of rods oontaining gadolinia, and the wate:r--to-fuel ratio are similar in the 8x8 and 7x7 designs, the neutronic behavior of the. two designs is not significantly different. The intemally located water rod in the 8x8 design redu:::es rod-to-rod power peaking.
Since the neutronic and thermal-hydraulic characteristics of 8.x8 and 7x7 fuel bundles are similar, their behavior under abnornBl. operational transients is expected to be canparable. The oonse:µmces of postulate:l oontml rod dr:op, fuel handling, and steam line break accidents are not expected to be significantly different for then<<> fuel designs.
The General Electric CCJnp:my, several utility a-mer-operators of boiling water reactors, and the Regulatory Staff have perfe>rlred analyses of ~
bebav.ior of 8x8 fuel in several mixErl and fully reloaded cares under transient and accident con:litions. These analyses predict that, for boiling water reactors which have jet punps, the peak clad ta:rperatures during a postulated large-break roc'A using the Interim Acceptance Cri tE-.ria are less for 8x8 than for 7x7 assanblies. HcMever, for large postulated breaks in non-jet pm,p plants and for small and :inte:cmediate size breaks for all plants, the predicted peak cl.ad teaperatures are :in the same range for both 8x8 and 7x/ fuel. Consequently, individual reviews by the Regu-latoxy Staff of the expected perforrrance of 8x8 reload fuel, inclu:ling plant-specific systen effects and any significant oore fuel loading asynmetries, will be required for each reactor prior to operation with 8x8 fuel to determine limits on reactor operating conditions. Tne can-mi.ttee wishes to be informed ooncerning the results of these reviews for the initial 8x8 fuel loadings :in each of the several General Electric boiling water reactor prcxluct lines.
The P.egulat:ory Staff plans to use the results of recently conducted spray-cool:ing and refl.ooding tests of a Zirc:aloy-clad burrlle to verify analytical ncdels for 8x8 fuel. The Ccmnittee wishes to be kept informed..
Experience and info:ma.tion exist both on the perfo:r:mmce of fuel reds and :bulxlles whose designs bracket the dimensions of the 8x8 fuel and on the perfanrance of cares oontaining mixtures of assanblies with different nuiroers ani sizes of fuel rcxis. Although mechanical tests have been nerfo.r:med on 8x8 fuel assenblies a..--rl ccmpor.ents to dem:,nst....-ate their integrity, additional tests to verify spacer* grid strengt.11 have been requested by the RegUlatory Staff. 'I.his natter should be resolved in a nmmer satisfactory to the Regulatory Staff.
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Honorable Duey Iee Ray Februa:cy 12, 1974 The General. El.ectric Ccr.lf8I1Y has pla,ned a program of both pre-and post-ir.radiation examinations to m:mitor the perfoDtBnee of 8x8 fuel assemblies.
The Corcmittee endorses a ccmprehensive surveillance program and wishes to be kept infornm..
The Regulatory Staff is currently reviewing the treatm::mt of uncer-tainties in the establisl"ment and no:nitoring of operating limits for boiling water reactors. The ccmnittee wishes to be kept infomal.
Re-evaluation of core operating limits will be necessary as a result of the recently pnm.tlgated Acceptance criteria for ~ency Core Cooling &.[Stems.
The Ccmnittee,;,rl.shes to be kept infonra:t.
The Camd.ttee believes tr..at, with due rega.zd to the above corrments, inclu::ling the individual reload reviews ey the Regulatory Staff which will address specific plant features, the General Electric 8x8 fuel assenblies are acceptable for use in the reload of General Electric boiling water reactors.
P..eferences attached..
2209 W.R. Stratton Ch.airmm
Honorable Dixy Lee Ray February 12, 1974 References
- 1. "Dresden 3 Nuclear Pa.ver Station, Seoond. Reload License Sul:mittal",
General Electric Co., Nuclear Fuel Deparbnent, September 1973, and Suppleaent A, Novatber 17, 1973, Supplement B, Decanber 6, 1973:
Supple:rent C, Decanber 6, 1973; Supplement D, Decanber 17, 1973; Supplenent E, Decanber 17, 1973; Supplement F, January 9, 1974; SU:pplarent G, Januaey 9, 1974; Supplement H, January 23, 1974.
- 2. "Nine Mile Point unit 1 - Secxmd Refueling", P. D. Raym:md to A.
Gi.ambusso, September 14, 1973 "Nine*Mile Point Unit 1 safety Analysis for Type 5 and Type 6 P.eload
- E\Jel", Niagara M::>hawk Power Coqx>ration, October 15, 1973 "Nine Mile Point Unit 1, Part 1, Non-Proprietal:y P.esnonse and Part 2,.
Pl:oprieta:cy Response," January 15, 1974
- 3. *~.aiticello Nuclear Generating Plant, Pentanent Plant Changes to Aooonnrdate F.quilibrium Core Scram Reactivity Insertion Charac-teristics11, January 23, 197 4
- 4. _NEIX>-20103,... General Design Infomation for General Electric Boiling water Reactor Reload Fuel Ccmnencing in Spring, 17 4", September 1973
- 5. H. E. Williamson and D. c. Ditrrore, "Experience with. BWR Fuel Throug'h September 1971", NEDO-10505, ~.ay 1972
- 6. GFAP-4059, "Vibration of Fuel Rods in Parallel Flow", E. P. Quinn, July 1962
- 7. Letter, J. A. Hinds to v. Mx>re, February 4, *1974, "Proprietary Infornation, 8x8 Fuel Wear Tests" Letter, J. A. Hinds to V. Mx>re, February 4, 1974, 8x8 Fuel Sur-veillance Progiam
- 8. NEIM-10735, 11Densification Considerations in BWR Fuel Design and Per-fontanee", D. c. Dit:m:>re and R. B. Elkins, Decanber 1972, Supplement 2, "Respor.se to AEC Questions, t-~10735.April 1973 (ProprietaJ:y),
Supplement 2, "Response to AOC Questions, NEDM:-10735 Supplarent 1",
~.ay 1973 (Proprietary), Supplement 3, "Response to AEC Questions, NIDM-10735, Supplement 1, June 1973 (Proprietary), SupplE!!lellt 4, "P25p0nses to AOC Questions NEDM-1073511, July 1973, (Proprietary),
Supplerrent S, "Densification Considerations in BWR Fuel", July 1973 (Proprietary}, Supplernents 6, 7, and 8, 11Fue1 Densification EffectS on General Electric Boiling Water ~
Fuel".
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Honorable Dixy Lee Ray
-s-February 12, 1974 References* (oont'd)
- 9. NE00-20181, SUpplE!O:!nt 1, Decenber: 3, 1973 (Proprietary)1 GEGAP-III,
- A M::xiel. for the Prediction of Pellet COndtct:ance in BWR Fuel Rodsn
- 10. "Technical Report on Densification of General Electric Reactor Fuelsn,
- u. s. Atanic F.nergy carmission, August 23, 1973, and "Supplarent 1 to the Technical Report on Densification of General Electric Reactor Fuels", Decenber 14, 1973 ll. "Sensitivity Stu:ly on BWR/6 Fuel Bundle Response to a Postulated r.t:X:A",
C. M. M:>ser arrl R. ti. Griebe, Decenber 1973
- 12. NEDE-10801, "M:x1eling the BWR/6 Ioss-of-Ckx:>lant Accident" Core Spray
_axxJ. Bottan Flooding Heat Transfer Effectiveness", J. D. Duncan and J. E. I.aonard, MaJ:Ch 1973, and *Response to AEC Request for Mditionai Infornation on NEDE-108011*, May 1973 (Proprietary)
- 13. NE00-10993, neore Spray and Bottan Flooding Effectiveness in the BWR/6"*,
J. D. Duncan and J. E. Leonaz:d, Septart,er 1973
- 14. "Core 'lllernal Analyses of a Stainless Steel Clad Heater Rod Bundle",
- c. M. M:>ser and R. w. Griebe, Decenber 1973
- 15. "Status Report an the General Electric canpany 8x8 Fuel.Assenbly",
January 18, 197 4, USAEC RegulatOl:y.Staff
- 16. *Technical P.eport on the General Electric Company 8x8 Fuel Assatbly",
Februazy S, 1974, tJSAEx: RegulatOl:y Staff 2211