ML20127P778
| ML20127P778 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 09/18/1969 |
| From: | Hall W ILLINOIS, UNIV. OF, URBANA, IL |
| To: | Morris P US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| CON-AT(49-5)-2667 NUDOCS 9212030114 | |
| Download: ML20127P778 (5) | |
Text
,
t; ppg
~
NATHAN M.
NEWMARK 1114 CIVIL ENGINEERING BUILDING CONSULTING ENGINEERING SERVIC,ES URUANA ILLINOIS 618o1 18 Septen6er 1969 Dr. Pe ter A. ibrr is, 0lrector Divis ion of Reactor Licens ing V. !. Atomle, Energy Conniss ion Washington, D.C.
20545 Re:
Contract ib. AT(49-S)-2667 Monticello Unit No. I Nor t he rn S t a t e s Pc,we r Corpa ny AEC Docket No. 50-263
Dear Dr. tbrris :
Cn 17 Septer+er 1969 1 vis'Ited the cons t ruct ion s ite of Monticello Unit 1.
The corning was taken up by an Inspection of the facility In the cocoeny of Northern Sta tes Powe r Co., Cencra l E lec t r ic Co., Becht el Cc,rporat ion and ORL personne l.
The af ternoon was devoted to a meeting-discuss ion centered about a lengthy lis t of quest ions which 1 had prepared prior to the trip.
The visit and discussion served to clarif y many of the points ralted in the neet ing, and the findings thereof will be reflected in the draft report scheduled to be prepared by Dr. Newm rk and we within the next several weeks.
There st til remain a number of points on which addltlonal Informatlon 15 required before we can ccelete our review and evaluation.
All of these top ic s, lis ted below, were t ransmit ted inf ormally to the appl lcant during the course of the vis it, and have been reviewed by Dr.
N.
M. Newark as well.
1.
Dynamic Anal ys es (a)
For the July 21,1952, N69V Taf t accelerat ion-t ire record used 9212030114 690918 y
PDR ADOCK 05000263 0
4 2
In the t ine-history analyses, the applicant is reques ted to document the time length of record enployed.
Also, it should be conf irneu that the sane t ime length of record was us ed f or the spec t run, c moer lson presented in F ig. 12-2-9 of the FSAR.
(b)
The fourth parsgraoh of page 12-2.8 concerns the des Ign provisions made f or Class ! I t e rn located ln Class !! structures.
The first s e nt ence of that paragreph Indicates that certain portions of Class !!
S tructures were fornally des igned as Class ! structures, whereas the third sentence notes that a f ornal des ign analysis was not carried out.
It wa s learned at the 17 Septen6er 1969 nceting that actually only a partial analys is of the type employed for Class 1 structures was undertaken.
It Is strongly suggested that the paragraph be revised to reflect the actual analys is-des ign procedure cert led out.
(c) for those three itens f ornelly analyzed by the response spectrum method, as listed on p.
12-2-9 (7/2/69) namely the recirculat ion lines,
the suppress ion chamber, end the 20-inch sect lon header, it 15 requested that a recheck of the onelys is be carried out to assure that the designs are conservettve, and that the res ults of the recheck be documented.
It has t.een pointed out by us previously (Dresden 2 and 3) that the nethod employed could lead to unconservative results.
(d) The applicant is requested to confirm that all Class ! I t ens were checked during the design to be sure that they net the applicable criterle for both the Cesign basis Earthquake loading condition as well as the Operat ing Bas is Larthquake load ing cond it ions.
(c)
The applicant is-reques ted' to clarif y the discuss ion, beginning at the bottom of page 12-2-6 and carrying over to page 12-2-9, concerning reanalysis in certeln cases of 5ys tens analyzed by the tine-blstory v
-p gr,-r,--ewq-un,,,
res.,y.g%---s-v.--yw y-i-s--m.--
yi, ntr-v-3
-ye
-r-em-.-y-ewr1---
ta, cM y-t-+
r+'c=yw
+-
y tw-A-%79---*-e-5,-*-e y-
--py*w--
3-+
g+g e-Je-
==*<-<'T ew u
3 i
approach.
In particular, what is meant by the term " subs tant ial dif f erences,"
and what was the bas is adopted f or tradif ying the m> del and subsequently dec id ing that the res ults were sat is f ac tory.
(f )
1he second f ull paragraph on page 12-2-9 includes a tabul6r lis t ing of emilficat ion f actors.
How were these values selected and how were they used in the analyses ?
(g) A description of the piping analysis technique is presented on page 12-2-10 et seq.
It is unders tood that all piping was analysed by this technique e xcep t for the recirculat lon lines and the 20-in. suction header which were ref erenced as being analyzed by the response spectrum rethod.
For the piping analyzed by the technique descrit ed on page 12-2-10 et seq. the following Information is requested:
1)
The esplicant is reques ted to conf irm that the analys is was carr ied out for both the Operating Da<it and Des ign Des is Earthquakes.
- 11) The applicant 15 reauested to provide a tabular survery of sample stress results locluding selsmic, dead toed, pressure and thermal effects, as appropriate, to denenstrate the conservat ism In des ign.
111)
The tabulat ion reques ted in 11) should include a conpar ison with code allowable stresses or other stresses speelfled in the design criteria.
2.
Reactor Internals The des ign criterion for reactor internals as presented on pages 12-2-5 and 12-2-6 refers to " clastic and plastic strains." The applicant is reques ted to provide a descript ion as tv how the plas t ic st rains were calculated; and a descriotion of the bas is by which the computed s t rains were compered to the design criteria.
Onl y in t his manne r can one ga in s orre centeclatlon of the norgin of saf et y that ma y e x i s t.
\\
4 l
An energy criter ion was also listed in the sane citation as being apnlicable.
Was this criterion actually used (a) in evaluating the design of the reagtor inter nals, or (b) anywhere else in design of the facility *t 3
Strest Criterla On page 12-2-4 et Sco of the FSAR ref erence is made to stress llwits of "150% of AISC allowables f or structural steel. -90% of yield s tress for re inf orc ing s t eel. -LST of ult imate s t res s f or conc retc."
The limits 6
cs given are not comparable limits so for as margin of safety, i.e. the stress lirrIt f or concrete given generally inolles maximum ultimate s trength without eny reserve whereas the steel stresses given do provide for a 4
i Was this criterion enployed? If so f urther anplif ication is reserve.
regulred to enable an evaluation of the margin of saf ety toat noy be availat-Ic.
h.
_T h* r na l 1.on d_s The apclicent 1$ requested to verify that in all applicable cases, as f or e xample f or piping and equipment, the rmal loeus we re cont >lned direct ly as appropriate.
5.
Feistric Criter la f or Eaulow nt Pr oc ur eme nt The criterla given in the PSAR f cr Class 1 equipment Indicate that procurenent must include provls ton to meet s elsmic requir ements.
As indicative of such procurement practices, Jhe applicant is reques ted to supply the seismic des ign criteria f or several items, 55 for exanple the main steam isolat ion velves, and the bat tery racks, and an indication of the manner by which checking is undertaken to insure that the procurement requirements have been evt.
^-------~_m__,__,__
5 As a concluding remark I thould like to add that I was favorably lepressed by the s tatus of the " housekeeping" that has apparently been nointained at the plant, and in a gross sense (vlsually) a high level of "craf tsnenship" seens evident.
Respectf ully submitted, l
l! a W. J Hall b)w cc:
N.
M.
Newmark 4
4 e