ML20031B760
| ML20031B760 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 12/06/1972 |
| From: | Ziemann D US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8110060056 | |
| Download: ML20031B760 (11) | |
Text
c -
LICENSE AUTHOR;TY Fl!.E C*s".r M'
t.-
ATOMIC EN:'RGY CCMM SS!O t i,.s h g'.^l**l % "tPh 1ffQ C
) 'N..J D
['jj[
s_
W ASHlWITo.4. D.C R 'A S
.- 1 1.7
'*'-~'
N u &;.
%wW Cf
,a ;u
,o La..
9
&n 4]MM.W Files (icchet No. 50-155)
T11RU:
D. L. Zicnann, Chief, 01U3 #2, L j(1 71, y v.
mw RELOAD G ED NF6-DA 11 x 11 ROD BUNDLES UITH CPOUE?ID RODS ASD PLUTJIC:
Discussion Consumers Power Compa.y (CPCo) hcs requested approval (1) to begin the transition to Relcad G fuel by inserting -wo lead bundles into the Big core during the February - March 1973 refueling outage and Rock Poin t (cycle epproximately 21 additional Ralcad G assenblics in February 1974 ill and each succeeding refueling thereafter(2) and (2) to inscrt four Nuclear Fuel Scrrice - De.ans tration Asscr.bly (ES-DA) fuel bundles into the big Rock Point reactor during the rebrt" ry - March 1973 refueling outagc O).
Each Reload G bundle contains one vrpowcred solid circaloy center rod and 24 plutonium-uranium oxide fuel rode arranged
.n a 5 x 5 array in the center of an 11 x 11 fuel bundle rod array (about 1.4 h; of recycled plutcaium pcr bundle).
Each RFS fuel bundic contains upcreninately 1.35 kilegrams of fissile plutenium er about three tiracs the normal en.i of life sc1f generation icvel.
The NFS fuel bundics are describh by CPCo(l) as a neu type of fuel bundle four using an 11 x 11 fuel rod arrcy with eight hallou unpowcred rods, to the center rod the corners e.nd four in diagonal positicas next etthat vill enable Eig Rock Point to cect the ACC Interin Acceptance Criteria fcr Facrgency Core Cooling Systens vith future reloeds of this For the US fuel bundles, the calculated nanitun fucl clad tceper-ature resulting from a lots-of-ccolant accident is reported to be 2129'F typc.
to 2740*F for Type F fuel vith 9 x 9 fuel red arrays that in co.trast is currectly used as reic.ad fuel (thrcugh February - March 1973 refueling).
E;th prepared fuel bundles erplcy 11 x 11 fuel rod arrays with reduced rod diam _ter to lever the linear hcot gencration rcte.
Foth the NFS t e r;;c t rods in the corners as rnd Relcad G fuel bundles vill use cobalt As noted, NFS-DJ, var originally describedll) practice.
is the curr:nt t.nuv'.;crcd hallow rods in the corr ers ar cell as the diac,oncls acxt uitn cince the unt generation in the cobalt to the certer rod.
Foucea,
in negligibly cnall cenpred uith iucl rods and since rhc t a r e c h.
impoctance el corner rods es a heat sini' f olleving a LOC!t is relatively to tk rubstitunicn of low, ue hcve attached no safety signific..cein the ccruer positions of MTS fuel bundles (d ccLalt target rods place of ho))cu rode;.
Th > cauty s nects cf the tarce cobalt rods na safety signifi-were evaluated previously by un and dcrc :ined to itaw caccc.
Target redn siullrr to thase 2.n thc LN and I;elcad G bundles h;xe been in u/e at Dig Roc! Pulat f or s.: eci al y eara cithout incid cut.
Uc. forther eve.luatica of ev* cit tcr;tt re :s is co m ylated
_t this tino.
8110060056 721206 PDR ADOCK 05000155 P
ppy
, grC 6 E/2 Files We met uith representatives of CPCo and Jersey Nuclear Company on November 2,1972, to discuss calculational nethods and other design features of the proposals.
The following tabic, Table 1, prepared f rom information readily available in the Eig Rock Point files shows tha t:
1.
The total ucight of f uel and clad for 11 x 11 and 9 x 9 rod arrays are approximatcly the same.
2.
The average linear power gencrc. tion in the B ruel, NFS-DA, and Reload G fuel rods is 1, or (67%) of the power generated in Reload F, J-1, J-2, and Et1 fuel rods.
3.
The total fuel rod heat transfer surface per bundle is increased by 121 (.4 49,) -1 or 19%.
81 (.5c25)
Reduced power r,cacration per red results in 1 css peak energy stored uithii. the fuel rods during rated pouer conditions and consequently more heat storage capacity f ollowing a loss-of-coolant accident.
J'able 1 Type _ Fuel B Fuel UFS-DA Reload C J-l J -2 EEI Reload F Rod diancter inches 0.449 0.449 0.449 3.5625 0.5625 0.5625 0.5625 0.050
- Clad thichness inches 0.034 0.034 0.034 1.040 0.040 0.040 0.040 Rod array 11 x 11 11 x 11 11 x 11 3x9 9x9 9x9 9x9 Hetal/ rater ratio 0.915 0.915 0.915 J.99 0.99 0.99 0.99 Ut Pu02 and UO2 kg
bundle kg) 0 1.85 1.4 0
1.5 5.33 0
Ut bundic lb "A
NA 445 453 H +'-
NA NA 6Pu and U,nctal I
(..-.
Files p;
~ ~ b, o 1914 Reloac G J-l J-2 EEI Reload P '
Type _ Fuel BFugl,lUFS-D!
Gadolinium rods / bundle 0
0 4
4 NA 4
Diametral gap in L/D 0.008
.0085 0.0095 Pellet L/D 1.61 0.75 NA - not availabic.
- Clad veight per bundle same for 11 x 11 and 9 x 9.
Shortly af ter the Big Rock Point reactor nas started up in 1965, cperation uith Type D (11 x 11 fuel rod) fuel was authorized.
Thirty Type B fuel '
bundles vere irradiated for the decign lif erine (3 ref ueling cycles) withcut f ailure.
The trend following cctpletion of 17pc B fuc1 bundic irradiation was touards fuel bundics ulth fewer rods per bundle.
This trend is neu being reversed wich the two Reload G and four NFS-DA bundles to be inserted during the February - March 1973 refueling outage.
The ccchanical dif ferences between the f uel bundles with 11 x 11 fuel rod arrays originally irradiated in the Ea g Rock Point core and the Relcad G and NFS-DA fuel bundles involve; an inert Zr center rod that retains the 3 anlal red spacers a.
in Reload G bundles, b.
an upper tie plate design that f acilitatec undarwater disassembly and replacement of Reload G bundle rods, the use of the tubes in corner positiors of LTS-DA as structural c.
nenbcrs to tie the ansc=bly together, us capture rods for tha five spacer grids and as cobalt target rods, and d.
f our non-fueled tubes positioned diagonally next to the center rod of the T.FS-DA fuel bundles.
The Reload G and UFS-DA assenblics also dif f er fren previous 11 x 11 fuel bundles in that these rcccat designr use recycle plutoniur fuel.
There are 24 Puo.-UG, fuel rods uith 4.37, ficcIle plutoniun in natural ia cach Relo$d G fuel bundle and 73 ru?;-UO2 fuc1 rods containing
~
UO2
t Files gg
.g;q in the NFS-DA 1.03 w/o and 2.45 w/o fissile plutonium uith enriched UO 2 With the enception of the unpoucred center rod in Reload G fucl bundle.
fuel, the four unpowered diagonal rods next to the center rod in the NFS-DA fuel bundle, and the use of plutonica rccycle fuel as fissile fuel enrichnent in pla:e of U-235 in both the Reload G fuel bundles the noted dif ferences are relatively minor and the f our NFS-DA bundles, The unpowered reds provide additional and require no further evaluation.
hcat sinks that are calculated to reduce peak clad temperatures for fuel rods within the bundic following loss-of-coolant accidents from 2700*F to <2300*F assuming autenatic depressurization and autonatic activation of the emergency core spray systen.
The increased quantity of plutonium in the Big Roch Point core introduces the possibility that core neutronics are affected unf avorably or that the increated toxicity of plutonium results in an unacceptable increase in radiatica doses to the public during nornal or post-accident conditiens.
We have censidered reactor kinetics and the radiological consequences of reactor operation using ".cload G fuel centaining plutonius to replace resident fuel over the four-year period for both normal and accident We also have identified in our evaluation the unique conditions.
dependence on unpowered fuel reds for Relcad G and FFS-DA fuel bundles te satisfy the 2300*F tenperature limit specified in the AEC Interim Acceptance Criteria f or Energency Core Cooling Systems.
Evaluation 2 rods containing a total of 1 kg of plutonium (6) ucre About 32 Pu0 ~U3 2
Ten inserted in the Big Roch Point core, two rods per bundic, in 1969.
CPCo of these rods have becn removed and destructively examined.
representatives have stated that no deviation fron predicted behavior fuel bundles (7) containing about has been detected.
Three EE1 PuO -UO2 2
Two J-2 PuO -UO2 6 kg of pl stonium per bundle vere inserted in 1970.
2 fuel bundles (8) centaining abcat 1.5 kg of plu:oniua per bundle were These bundles will be inspected during the February inscrted lu 1971.
1973 refueling outage and one of the eel bundles will be renoved for more detailed eratination.
To date nene cf the pug -UO2 rods irradiated 2
Since the fuel rod configuration in the Dig Rock Point core have failed.
for all of the mixcd oxide fuel rods irrcdicted in Eig Rock Point to the present time has been a 9 x 9 rod array, the linear rod power generation is approximatcly 50% greater thcu uill be encountered in the Tac reduced fuel and clad tcuperatures of Reload G cr I:FS-DA fuel rods.
the new fuel bundles will reduce tne pcssibility cf fuel rod failure.
4
. CSU g g73 Files The plutenium inventory produced from U-238 in the Big Rock Point core with the equilibrium U-235 core prior to the insertion of mixed oxide fuel. rods in 1969 was approximately 40 kilograms according to CPCo calculations shoua in Tobic 2.
When the equilibriun Reload G 21 Reload G bundles core is attained af ter 4 refueling outages (about to be substituted f or depleted bundles at cach outage), the plutonium CPCo has reported inventory vill increase to about 133 hilograms. rods positioned in the bundic interior that uith the mixed oxide fuel as in neload G and EFS-DA bundles, core behavior characteristics vill not change cignificantly and the effect on reactor control is negligibic.
the kinetics parameters for the core fully loaded We have concluded that with Reload G fuc1 bundles seem reasonabic cetpared with core parancters Substitution of the 11 x 11 furl rod array for a U-235 cariched cere.
uith mixed oxide fuel rods in the bundic intefior reduces the severity The acount of fuel above 265 cals/gm of a control rod drop accident.
follcuing an assuced 0.021 ah rod drop cccident is 139 kilograms, according to CPCo, in contrast to 232 kilograms for the U-235 cnriched We have concludad that the change-core uith 9 x 9 fuel rod bundles.
to the nixed onide core described vill provido a treater nargin-to-fuel-rod f ailure and reacter raf ety is chcreby enhanced.
The possibility of misplacing a highly enriched plutonium rod uithin a fuel bundle during fuel bundic f abrication has beca investigated and, as uith other evaluations of misplaced highly cariched uranium fuel rod clad failure could occer during normal reactor operation
- rods, Such a failure if a highly enriched rod is misplaced uithin the bundle.
is undesirable, but we have concluded it is talcrabic and uill not result in continuous radioactive releases in excess oE percissibic An error in placement of fuc1 rods in the bundic operating Icvels.
uc consider to be very unlikely in vicu of rod identitication and quality assurance procedurcs.
ef f ects resulting f rom the une of mixed cxide fuc1 Of fsite radiologica]
as described by CPCo arc not significantly dif ferent from those previously cvaluated for the Dig Roch Point f acility using U-235 enriched fuel.
the of f site dose rates contributed by plutonium, Analysis reveals that as determined by utilizing measured plutonfun vapor pressure for 5 v/o nixed oxide fuc1, are nc;11gibic co;,ared uith the dose rates fron Uc have concluded that the increase in plutontun fission products alone.
inventory for the equilibrium Relcad G core (Tabic 2), 3.3 tines greater is insignifi-thsn the Big Roch Point cerc without recycle plutonium, cant uhen the relative biological inportance of plutoniua accopes (10 Crn 20 limito) is considered.
)
l.
'T~A.B L 'E
?-
IT,Uf0tTIU: Ilh.uT6RY pit 0JECTI0t!
BIG h0CK TOII;f liUCIE/dl PIddif
- l. _ _
EOT.
- EDI, l
CYCIS l
Cf
,,{
l QlhW (kg)
L l
Co c 21 24 33-40 Typical all U02 Precent Core,Iby 1972 - Feb 1973 - Includec 22 EMI-Pa roSn, 3 EEI-Fu and 2 J-2 bundles 36 43 h6 55
~
Mir 1973 - Feb 197h - Includen 2 EEI-Pu, 2 J-2, 4 ITFS, 2 O bundles and 7h Uo buncle 35.3 42.4 45.2 56.5 '
2 Mar 39'(4 - Feb 1975 - Includen 2 J-2, 4 !!ITi, 21 G and 57 UO2 bundles 46.2 56.8 53 9.
69.o.
I I:. 1975 - Feb 1976 - Includec 2 J-2, b
h HTS, h2 G and 38 UO bund 1cc 62.9 79 9 68.0 89.6 i
2 Mar 1976 - Feb 19'(7 - Include, 63 G cnd 21 UO bundlen 77.4 200.6 80.8 108.1 2
Ihr 1977 - Feb 1978 - Includes 81 G bundlec 96.6 128.2-96.2 133 1 i
t C
( Ys Cr
--Cis -
i-sN TJ
/
i 4
.-,..-s
,5
~
t
.#_ b, 6 S,t.9 tilcs p.-
The yield of' the various fission products is dependent on the fissile Fission of the plutonium isotopes Pu-239 or Pu-241 results isotope.
in a significant reduction of accident whole body and bone doses uhen conpared with the doses f rom U-235. fission products but results in an Jctscy Nuc1 car has calculated that the increase in thyroid doses.
thyroid dose for the equilibrium Reload G fuel core is incrocscd less Uc have concluded that than 4% and remains eithin 10 CFR 100 limits.
the inprovcuent in fuel integrity due to reduced linear rod power density and the reduction of calculated peak clad temperatures f ollcuing LOCAs adequately coupensates for the relatively small risk associated with the calculated 4% increase in the thyroid dose resulting frou an assumed release of el) iodines from the mixed oxide fuel.
The calculational models and assuuptions used in the-analysis of the NFS-DA fuel bundles are described in NEDD-10329 (as amended te comply with the AEC Interin Acceptance Criteria f or ECCS) uith modifications (2) a 0.96 gamma smearing f actor, and f or (1) non-jet puup) plant, Based on our cvalua tion of the DBA vith NFS-DA (3) unpoucred rods (l.
fuel bundles in the core, ce have concluded that the dependency on the DSA unpovered rods to limit pcaa fuel clad temperaturcs followir.;
crectcs uncertainties that cannot be eliminated until demanstration tests of unpowered rod ucttings and heat sink ef fcetiveness arc con-plcted early in 1973. We cannot agree that pcsh clad temperatures are spray cooling uill be lower than folleuing the DBA and lou pressure the 2300*F limit specified in the AEC Interim ECCS Acceptance Criteria.
that the nev bund 1cs vill 5ased on our review, houcver, it is evident operate at lower heat generation rates and it is th arefore reasonabic Because of the reduced to enpect that fuel integrity has been enhanced.
power per rod, fuel temperatures and stored energy are reduced and there is a greater acrgin to clad f ailure er excessive clad temperatures It is also reasonabic to expect that the unpowered following DBA.
rods properly positioned in the bundle util provide an additional sink to which the hottest rods can radiate hect for storage (unwetted) or transport to acclant (wetted). Uc hava concluded that unpowered rods vill reduce pcan fuel rod clad tcmperatures but cannot ngrce the codcl and acsumptions used by General Electric are conservative that i.e., peak clad tcuperatures rey 'ec reduced from in this respect, the 2700 - 2300*r, but the reduction uay not be sufficient to mect AEC Interim ECOS Policy limit of 2300*P.
Uith a calculational model cimilar to the CE nodc1 and the same D3A Jercey Nuclear has shown thet a single unpoucred solid assumptions, airculoy rod in the center of the 11 x 11 ReJoad G fuel bundles will linit pech fuc] red clad taperaturer to 2296*?.
The uncertainty casociated uith unpoucred red uctting rcrains and our conclusions regarding the Rcload G ECCS calcuja:icns by Jersey Nuclear are the some as our conclusions f or the 1.fS4A bundleu.
4 i
(
,g. DEL, d.al.,
Files Additional information(4)(5) provided by CPCo described the ccusequences of intercadiate and small size. breaks in the primary coolant system af ter plant nodifications are comp 3 eted in the year 1974 to provide automatic primary system depressurization and assuming feedwater pumps Until the-are restarted nanually within 10 ninutes of the breah.
reliability of the proposed automatic depressurization systca can be established and the dependence on off site power to run a 1.3 MW electrically driven fecdwater pucp f ollouing a less of primary coolant associated with the DBA can be justified, and for the sane ressc. t that the AEC Interic calculational uncertainties, we cannot coat-.the 2300*F temperature limit, vill ECCS Acceptance Criteria, i.e.,
be satisfied over the range of small and interttdiate size breaks.
Based on the inforw.ation provided to us, however, ec have concluded that the integrity of the 11 x 11 fuel bundics should be superior to the 9 x 9 bundles presently in the core during nornal and accident conditions and that CPCo should be authorized to insert the 2 Reload G bundles and 4 NFS-DA bundles during the February - March 1973 refueling Ue note that the propesca change to permit automatic depres-surination follecing loss-of-coolcat accidents is only partially ef fcetive outage.
for resident fuel according to the GE calculations and assumptions (4)
Our evaluation over the postulated range of coolant system breaks.
of the ECCS will continue as new information is presented by CPCo
'~
in the areas we have identified.
The necessity to provide additional inforcation related to fuel shielding Tnc and transpor tation has bean discussed with CPCo representatives.
increased spontaneous neutron population that accompanics irradiation of r ecycle plutonium-bcaring fuel risy necessitata new. restrictions on the nunber of asse.blics that can be shipped in approved casks, additional neutron shielding nay be required, or new casks cay be CPCo plans to subnit additional information before irradiated proposed.
recycled plutonium fuel bundles (Reload G or NFS-DA) are shipped from the site.
Doth solid and hollow unpovered rods have becn utilized in the proposed Reload C fuel bundles contain ene solid mixed oxide fuel assemblics.
unpoucred center rod and the I.TS-DA bundles each contain f cur unpoucred Jersey Eur 1 car selected hollou rods diagonally ncnt to the ccnter rod.
the solid red because the 3 axial spacers in cach bundle are attached to the center rod and uncertaintics related to collapsc or rupture during There is no similar rapid accident coolant bloudown are clininated.
bundle. structural dependence on the 4 unpowered rods richin the NFS--DA fuel bundle, but it is neverthc1 css deairable to preserve the helJow The nochanical ef f ect tubular shr.pc assumed in the L' CA cvalua tio :s.
of bloudon cn the hollow center rods hnve bcen analyzed by KFS and according to the calculatcd resultr the hollow rods ccn withstand thc bicudown f orect during LOCAs witbout failura.
.n
~
(
riles DEC 6~6.7.
Conclusion
. Uc have concluded that the Reload G fuel bundle; vith an unpowered rod in the center of each bundle and the four NPS-DA bundles with to the center red ir. cach bundic, both ceploying 4 unpoucred rods next 11 x 11 rod arrays and recycle plutonium, vill result in reduced fuel rod-and clad -temperatures during normal and accident conditions and for this reason the request to insert 2 Reload G and 4 NFS-DA fuel bundles Uc cannot should be granted _ since reactor saf ety uill be enhanced.
that the unpovered conclude, until neu test data become available, rod wetting and resultan' pe '.. clad temperatures as calculated by Jersey Duclear and General "
Ac are conservative and uithin the litits of the AEC Interim Po~
S tatemen t.
Ue have considered tlm plutoniun inventory increase and the plutonium fission product yields in relation to normal and accideat releases the proposed and radiation dose consequences and we have concluded that change to a plutonium recycle core does not precent sign.ificant hazards considerations not described or implicit in the Big noch Point Safety as ancnded, and that there is reasonable assurance Analysis Report, that the health and safety of the public vill not be endangered by On this basis, operation af the reactor in the nanner proposed.
Ancndment 4, which increases the anount of plutonium that CPCo is authorized to receive and possess, is justified.
It should be emphasized that according to calculntions by Jersey Nuc1 car and General Electric the AEC Interim Acceptanea criteria for the DEA large pipc-broah LOCA vill be satisfied by red;:ing the power generatien per roj (11 x 11 rod arrays instead of 9 n 9 arrays) and utilizing To satisfy the AEC Interim unpovered rods at or near the center.
Criteria for the entire range of primary systes breaks vill require cdditional modifications to t'e ECCS (an autenatic depressurization system has been propos:d) which nust be approved by AEC before instal-lation at the Big Roch Point plant.
It appears that coupletion of ECCS modifications to acet the AEC Interia Acceptance Criteria vill not be l
accomplished before July 1974.
I T [J w m \\,aca n Gy /
t vs pancs J.(,b 4peratin$fdeactors Branch 02 Direc6 orate of Liccusing
Enclosure:
References l
cc:
Sec next pnte l
L
i Files CEC C 1972 i
R. Tedesco, L:CS (2) '
cc:
P. J. Skovholt, L:0R RO (3)
D. L. Ziemann, L:0EB #2 T. J. Carter, L:0R J. J. Shea, L:GRB 62 Q. Jinks, D?dt (2)
R. M. Diggs, L:0R3 #2 PDR E
?.
t C-t' REFERENCES _
Design Ecsis Accident Loss of Coolant Anclysis for NFS Demonstration l.
~ Fuel Assctblica - CFCo Iceter dated Mcy 18, 1972.
~j I
Proposed Change No. 31 - Reload G containing 24 plutonium-uranium l
2.
oxide fuel rods and onc unpoucred rod at the center.
two lead buncles f or insertion into Big Rock core during the February, March 1973 refueling outage.
CPCo letter dated June 16,197.
34 - Four KrS-DA fuel bundles uith eight unpoucred Proposed Change No.
3.
rods (4 hollow diagonal rods next to ccnter rod) cnd 73 plutonium enriched tixed oxide rods per bundle to be inserted into Big Rock CPCo Point core during February - March 1973 refueling outage.
" Big Rcch Point Loss-of-Coolant Analysis with Automatic Depressurication 4.
cud NFS Demonstration Fual".
CPCo letter dated September 22, 1972.
7 "Small and Interuediate Ercak Loss of Coclant Accident Analysis for 5.
the Big Rock Reactor uith en Automatic Depressurication Systen and Jerccy Euclear Company Reload G Fuel".
CPCo letter dated November 1, 1972.
6.
Amendment No. 3.
April 18, 1969.
Authority to receive, possess and use 50 kilograms of plutonium fuel rods in connection with operation of contcined in Pu0 -UO 2
2 the Big Rock Point Euclear Plant and opercte the reactor with one or tuo rc=ovable fuel rods cor taining Pu0 -UO2 inserted in 2
Reload "E" or "E-G" 9 x 9 rod arrcy fuel bundles.
The 32 pug -UO2 2
(1.3 - 1.5 r/o Pu) reds combined contain less than 1 kg of Pu when inserted with the Big Roch Point reactor ct the beginning of cycle La. 7.
The plutoniua in. atory in the core at the beginning of the fuel cycle is increased by about 4% and less near the end of the fuel cycle.
7.
Change No.19.
February 20, 1970.
8.
Change No. 27.
December 29, 1971.
9 e
_ _ - _