ML20024G811
| ML20024G811 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 09/30/1975 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | Mayer L NORTHERN STATES POWER CO. |
| References | |
| NUDOCS 9104300437 | |
| Download: ML20024G811 (7) | |
Text
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g p,, p g NRC PDR Local PDR Docket Doci:ct 1;o. 50-26.5 KRGoller TJCarter OELD OIGE (3)
Northern States Power Company DLZiemann NITN:
Mr. L. O. Mayer DBuckley Director of Nuclear Support lo.iniggs Services SVarga 414 Nicollet Mall DEisenhut itinneapolis, Minnesota 55401 TBAbernathy, DTIE ACRS (16) centlemen:
RE: MONTICELID NUCLEAR dENERATIM PIMI' Your letter dated August 7,1975, referenced a report entitled, " Marl I Containtnent Status Report," dated July 31, 1975, prepared by the General Electric Company (GE).
Based on our review of the GE status report, we find that we need additional in9ernation to complete our evaluation. The information required is listed in the enclosure.
For your inforwtion, a copy of the enclosure was sent by telecepy to Mr.1. Keenan, Yankee Atortic Electric Company (Hark 1 Owners Group coordinator) on September 9,1975.
In addi+1on, inost of the concerns listed in the enclosure have been the subject of discussions between the NRC staff and GL.
It is anticipated that the responses to the enclosure will bo presented in the final report of the Mark 1 short term program scheduled to be issued at the end of September,1975, with the exception of the two items noted as long term program items.
Please contact us if there is any additional information needed regarding our request.
1 This request for generic information was approved by GAO under a blanlet clearance number Iwl80225(R0072); this clearance expires July 31, 1977.
Sincerely, Odginst nirned by Den r.: ' 7hmann Dennis L. Ziemann, Chief Operating Reactors Branch #2-Division of Reactor Licensing
Enclosure:
j 8:ecaest for additional j ),,,
Infornation G
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I Nortliern States Power Company l
CC Arthur Renquist, Esquire The Environmental Conservation Vice President - Law Library Northern States Power Company Minneapolis Public Library 414 Nicollet Mall 300 Nicollet Mall l
Minneapolis, Minnesota 55401 Minneapolis, Minnesota 55401 Gerald Charnoff Shaw, Pittman, Potts 6 1rowbridge 910 - 17th Strect, N. W.
hashingtr.n, D. C.
20006 Howard J. Vogel, Esquire Legal Counsel 27S0 Dean Parkway Minneapolis, Minnesota 55416 Steve Gadler 2120 Carter Avenue St. Paul, Minne.~ot.2 55105 l
Mr. Daniel 1.,
Iicker Assistant City Attorney 638 City llall St. Paul, Minnet.ota 55102 Mr. }:enneth Drugan Environnental Planning Consultant St. Paul City Planning 421 Wabasha Street St. Paul, Minnesota 55102 Sandra S. Gardebring Special Assist ant At torney General Counsel for Minnesota Pollution Control Agency 1935 1: County Road D2 hosevill e, Minnesot a 55113 Anthony 2. Roisman, Esquire Iserl i n, i:ois' ann and 1:essler 1712 N 51 reet, I.
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Wash;ngton, D. C.
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.s i, 1975 STRU~iUd,1:::G1 ;i:EI'.1: 0 9';T.3'i'IO"3 /SD P051T10:M I
1.
On Pare 1 of the report a s t a t en er.: is cade that "the
'.rh I cont-! --~..
will r.aint ain their function daring the r.ost probaule course of t;..
cvent or during S/R valve discharge".
a.
The expression "r.a.st probabic course of LOTS event" should be defined and justification should be provided to substantiate the exclusion or redu: tion in u r,nitude, if a: y, of indi. idual or conbi n cJ f r, o f f e c t s i f t h "r e rn'" e et rse..." is less scvere th a the worst passible LO:A cvent, b.
The bases for the exclusien of S/R valve discharge' loads from the. short tem progra, have not been prencatcJ in this report.
P.c'<
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c;.
"11st t'
nrhar;i inads en?
address the fo11c. 2nr paint s 1) th. px dli1) 0; ce :anin L/c valve IsaJs with other o
pool dy:,r cie l o.id s,
2) the pmibility and :tructural conseqt' ::es of t he S/R valv,;
dit cinrRe loads o.;currin;. near ihe en.! of a LOCA event aftcr a rise in prel t er.pcrat ur c,
3) t h t' ne;' it i. " oressu: e-: c r ir t in" capabilit'. of various struct"res d;.i:
J r..
it..c pn] p:
sure, i n cl ud i nr, 1 N 1 i:.:, platc e.
'o:
I,c e n t a i:r:, * : r.,
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the ponibilit y of c: citing the resonant requency of the f
ovalinn or brer.thir.g :. odes of the torus, or other dynamic inodes of other structures within the pool,
- 5) during the life of the plant the number of oscillations anticipated to occur above and below the clastic limit, with a supporting lo.: cycle and high cycle fatigue analysis for affected structures (long tern program item), and 6) the load-resisting capability of various structures when subjected to a LCTA near the end of the plant life after n.crerous cycles of S/R valve discharge lo..Js (long terr program itca).
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r 2.
- lhe results ntd conclusions presented in ite :S "a", "b" aih! "c" h t the top of Pa;c 4 're not substantiated in the report.
- lhe nathonaticci rrodels nn:! rutMJs of an:.1741s for items "a" and "h" are briefly di cu.mj in the lett er fron G.1.. Gycrey to R. becary dated June 26, 1975.
The structural c pability or the ring header and vent pipes af ter failure of the column asse:.bly has not been provided in either report.
For all structural analyres referenced in the short tcm progran provido the following:
a description of the r.nthmatical radel used in the analysis a.
including justificatloa ist the baundary conditions and a discus:.lon of the cor.putation of rotntional and trant.lational spri.; const..t:.,
b.
a descriptica of t he r.t h:ds of analyais er. ployed, incluJing reference to established cerpoter codes, types of cletents used, inclusion of shear deforu.ations, and non-linearities, n justification for sin.plifying assorptionr, saade in the analyses, c.
d.
the W e: ft: j r.; c.t l'
' c i a and a c ri al p.* op; rt i e r., and c.
a pres.cntation of resuhs a! cc.ne ? r. i t as t.hi c h. i uc l t 1) locat ion and rm: nit u Je of exce.' nive stresses or defon.at ion'.
for critica) ej er ent.., and 2) the juctification t hat such excessive st renes will not result in loss of fenetien of the contninrent or other safety roldtcJ
.p. tens, include I h.' strain rat c effect s, the accept aMe
. tit ratio?, th
- y 4f m of re ': ty, the Oc; co el u
conseit..;i n, pl yr;ca! testr., crack cont rol, effect b ca l eah t i r.h t ne s a,
etc.
3.
A discussicn of the five basic groupingr. of :.: ark I plants is prer.ented on Page 5 anJ det.iled i:. Tnbic 1.
Describe the bases for selecting the typical pinnt from each group for an'in depth analyses.
4.
Full scale hardware tests anc ' strain rate material tests are referred to within the report.
Describe the test procedure, detail simplifying.
assumptions, conpare the naterial used for the te-t with tha. used in your plant, justify the use of static tests for dynamic and cyclic loading phenomenon, and compare the test results with stat!c finite element analyses.
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5-4 5.
On Page 12 nnd 13. the fur P "ntal frequency of the ring header assen.bly is spew i kJ a.
h.
h o.ide the details LaJ proc.ccurts of annly:,is L.hich Icad to th. cr,tabli &.=t of this value.
Can higher nodon of the ring header assembly, its corpontnt part s or other structures within the torus be excited by pool dyna:nic loads?
6.
For the down:o.act latern1 load analyses, specify the nu.ber of cycles expected to result in the inelastic behavior of any element of the downcomer-header assembly and justify the integrity of this assembly by })crforning a low cycle fatigre analysis.
7.
Present dingrams which detail the distribution of the resultant doatnuard rd forca on the torut., piezented on Pago 17.
In the analysis and up i
of torus wr ' the folloiting should also be considered:
seismic loads in combinatio:..1;h de;.J, live and pool dynanic loads; the in ugrity of lateral bracing, diagonal.., etc. ; cuir a N.:kling; und the integrity of the. stiffening ring and column connections.
1 8.
" Accept abic st r:.in linits" are referred to on Page 17 Define these linits anJ justify their t '
for L,th steel..nd reinforad concrete
- axial, n!..a r and L. C a n, i e..
- i e :.
9.
The sp;cial considerntio:
of 5; cra"ranh "" 3131.? of Subsc: Lina NE of t ha /.L.'0! D G I V Com, Soe t i on 111, res t r ic t ya cid.ing t (> locali:d a rc a r..
Specify those pool dynto.ic loadc nhich produce only ruch local yieldinc..
10.
In the section entitled " Screening Analysis" on l' age IS several
" insignificant" loads are listed.
Spa ify.'cther ar not any of these inads could occur in combination with the lirimary significant pool d> wmic loads and, if so, that would be their percentage contribution.
11.
On Page If>
mt eent is nade that "V e'n t h =ders can hnndle fall!:c:L loads e m, aral columns are assumed to buckle".
Provide a descrip.jou
, analysis which technically support s the above 7
. statement, im ade a discussion of the buckling analysis of these f
~
- columns, in aJdition. demonstrato that after the potential failure of these columns di a to fallback loads, the remainder of the LOCA load:t can still be resisted.
12.
In support of the data presented'on the screening analysis, provide justification and sketches for any element in which stresses exceed the clastic limit, in particular, the vacuu, breakers and the relief valve line over the pool.
Specify the safety and seismic classification of these elements and provide justification that the failure of the element would not cauce loss of either the containment or the energency core i
cooling system function.
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i 13.
On P:>re 20, n corparir.on of other pl.'ntr> to the reference pinnt assut.ed a parabolic pressure tire pulse 1:ith a p.a). or' 17 psi and a duration i
of 20 1.i]111st..:.ls.
.lus t i fy th e...- vs.:aus in light of the apparent diseropar.:y with data prese te: on page 13.
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14.
Prova j u:t i f.it:iti~ for the use of a dynamic load factor of 1.3 and a dyn wie n11n. W e rir,'
' mase foctor of 1.4 ar preunt eJ an th-conpatison of other plaats to the reference plant, pages 20 and 23.
l 15.
provide a di cursion of the nnnlysis of the vcnt pipe bellous assembly I
which demonstrates its inter,rity 5. hen subjected to large deformations perpendicular to its axis of primary expansion.
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