ML19241B302
| ML19241B302 | |
| Person / Time | |
|---|---|
| Issue date: | 01/08/1976 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19241B297 | List: |
| References | |
| FOIA-79-98 NUDOCS 7907160018 | |
| Download: ML19241B302 (5) | |
Text
..
6l JA't. 0 61976 i
TOPICAL REPORTS EVALUATI0ft m
i TOPICAL P.EPORTS SUtif!ARY
~
s.
The'* topical reports evaluated in this review present results from small break spectrum '(At 0.5 ft ) analyses for 85'd's 145(I) 2 177(2), and 205I3) FA plants with internals vent valvis. The three
~
j reports were reviewed jointly because they usi the same small break model to perform the small break spectrum analyses.,
The small break codel consists of the three computer pro-grams discussed below used to analyze ple.7t response to small breaks:
- l. 'CRAFTI4): A nhltfr.cde representation of the plant pricary system to compute blowdown hydrodynamics and water inventory in pricary loop I
componentsfolicwingpipingruptures.
2.
FONf5): A single node representation of the core to ccmpute average two-phase mixture height in the core when core uncovery is computed
.in the heterogenecus. reactor inner vessel volume of the CRAFT model.
3.
THETAl-BI6): A mul'tinode representation of the core hot p'in fuel and cicd to compute ter.perature transients durin9the loss-of-ccolant accident up through core recovery based on average core coolant con '
I ditions determined in CRAFT and FOAM.
t The multinode plant reprc'sentations.in CRAFT for small break analyses typically contain approximately half of. the nodal detail used for large break studies ( ~15 compared to ~30).
The reduced medel has been
~
shown(7) to provide results essentially identical to those of.the larg o
~
break model when using identical assumptions, due to the reduced bicwdown rates and internal pressure gradients computed for small' breaks. ?!ast of the nodn 555104 2
,e I
g..,
.',. m e.
. c.,.r,. e, -i... c... - g :........,.,. g ;
.,.., f z...
.m.
w.
(, 2.
~'
.g.
JAN. O a lG74 detail reduction is made by lumping the two primary loops siculated in, the large break model inu.1 single loop, and by lumping the reactor inner
' vessel regions of care, core bypass, upper plenum, and upper head into T
In addition to the nodal reduction, some large break
..a single volume.
~
analysis assumptions imposed for tonservatism can be rela'xed because of
.the slower blowdown of the small break. These changes are:
1.
!!ormal system low pressure reactor scram is included.
- 2. All injected ECCS water is assumed to enter the dcwncomer and is retained in the CRAFT calculations. !!o conservative removal of this water at the end of blowdctn is used as
'i'
"?~..
.in the large break analyses.
A heterogeneous inner vessel voluEe is modeled for tlie small 3 d--
3.
Drea.k in CPAFT compared'to the homogeneous volumes' modeled 6W 1
- for the large break analyses.
cc:. U '- Results obtained from the' topical reports for the small-breaks considered for each plant are sue =arized in Table 1, and show that
~:: peak clad hot -spot temperatures in any of the three plant types analyzed 0
do not approach 2200 F.
~
TOPICAL REPORTS EV/.LL'ATION-The sma11' break model programs used in the analyscs in the three tcports reviewed hare were evaluated in previous assessments
~
for large break studies in the cases of CFAFT and THETA 1-0, and the FOMI program was evaluated in the review of BA!I-10064 Appl l cations e
M510s
~
O S:5.
,...i 63 m.oeim of these programs in the small ~ break analyses reported in the topicals were performed in a manner which provides some conservatism.in the calculations of peak clad temperatures,; however..an assess:::ent of the extent of this conservatism was not sought because the tempera-
,tures obtained were low conpared to damaging temperatures..
Froci the results su.r.iarize'd in Table 1. it is noted that the analysis for the177-FA plant with raised loops',did not include the core flooding tank line breck. The* introduction of the report (BAl.'-10075)(2f for this plant indicated that the results of the analysis for this break I
2 g
would be presented in the SAR for ea'ch plant application. The 0.5 ft b,rcok for this plant was al'so indicated in the introduction to be re-58) ported in D N-10053
., As this. report presents results for a 177-FAncn-
- +
vent valve plant using the large break model for the break analyses, it g
eak for the177-FA plant with raised loeps is considered that the 0.5 ft br and. internals vent valves has been adequately considered. The value shown in Table 1 for this, break is consider.ed greater than can be con-servatively expected for a small break model analysis when co. fared to 145'and 205'-FA results; REGUI.ATORY POSITIO:1 Referencing the appropriat' report of the three topicals evaluated e
in this revicu will be acceptable for sciall break spectrum analyses for SARs with the exception of SARs for 177-FA vent valve plants with raised loops which require additional documentation for the CFT line break.
The models and programs used for the small break analyses in these topicals pr'edate issuance of Appendix X of 10 CFR 50, but are corisidered
~
in conformance to the requirements of that rule.
555106 49
P A v e.uig gy TABLE 1
~
~
177 FA
. RAISE 0 2
Break Size - ft -
_145 FA
._ LOOP 205 FA (Pump Oi:;ct.arsc) 0.5 1196 1533(3) 1178
~
0.3
, 1030 1090 710(2)
'I.C.(I) 700(2) 710(2) 7 O.1 O.05 I.C.III 710(2) 700(2) 0.04 *
- i (PgpSuction) g 0.3 824 r
0.1
. I.C. III
~
710(2)
(CFTLine) 0.35 760 1
0.44 -
j636 l
t l
I I
TiOTES:
l (1) - Initial condition - not specified i
a e i [y j
(2) 'Same as initial condition r,s.: c. n
[hjf, y_)
, O !' '
I-i -
l (3) - From R5erence 8 5.0N LO CFT - Core Flooding Tank e
L
'.rc :. z..
...... t llc 1G7 p. ::...-
.t x :.. n v -
m.:: n : := :. :=n:.:: en.:
O
-t-
... v.. #. >.,
s
~
RElsu2rta c
C. E. Padr., R. J.' Allen, and L. R. Cartin, "?*altincd: In: lysis of' 1.
S. mall Drcs.s for act's 145-Puel-Assc:61y 1:uclear Plie.ts With Internals V'nt Valves," c10.'-10052, Octch r 1973 -
g L. R. C$rtin, J. M. !!ill, and C. E. Pad:s,. "!bltinode le.alysis of 2.
Smil Drc.f.s for D:W's 177-Feel-Asse:61y '?aclear Pbnts Mith Pal:cd Ircp,Arrcngc:r.::nt and, Internals Vent Valtes," Elsi-10075, Dacc.Ther 1973.
R. C. Jones, B. M. Ibnn, cnd C.' E. Pari:s, "itltilnda In21ysis of 3.
Scall BrcC:s for Bt.*i's 205-M1-AsscThly ?acicar Plant Kith Inte:nals*
Vent Valves," DJ'i-10074, Novc;riur 1973.
D. E. Birrgh:m, h'. L. Jensen, and R. A. !!cdrick, "CP7TI - D2 cription 4.
of Fcdel for Dpilibrit:n ILCA Analysis Pro;;:r. a," E;M-10030, 0:tcher 1971.
5.
D. M. Den, C. D.1bgan, and L. R. Cartin, ":-bitir.cco Analy'cis of Core Flccding Lt.r.c Ercah for BCi's 2558-M!t Internnis Vent Volvo Plants,"
F#!-lC054, 7pril.1973.
C. T. !!ocevar, and T. W. Wine!.nger, "'NEml-B'
,1 Garputer Ced.a for G.
Id.v.lcar Reactor Core tm.al Inalysis," H*e.1445, Febrr.ary 1971.
7.
C. E. Parks, B. M. Dc-n, and R. C. Jones, "!:citinc$c A.alysis of
.Saall Brch.s for S4W's 2563 Mit Nu*" Plants," 370.'10052, Septe bsr 1972.
C. E. Parks, L.,R. Cartin, z..d K. C. Shich, "!-hitir.cfc An:1ysis of 8.
v DI*i's 177-M1-Icsc.Tbly, Ken-Vent valvo Pl?.nt Caring Ic*7.," DX:-10053, June 1973.
l p.,
g,p c,. ? " '
~.
[]
[f '. ;,,.,
[
jy l[.
j ~. 7
..., O. o,
g g %, r.. :dygg/-
f mt e
g: ;>2-QQ aJv
- f. as.-
.