ML20090L817
| ML20090L817 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 05/10/1976 |
| From: | Mayer L NORTHERN STATES POWER CO. |
| To: | Stello V Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9102130392 | |
| Download: ML20090L817 (22) | |
Text
-
s 2
N S]p NORTHERN 5TATES POWER COMPANY M SNN E A POLle MINN E G OTA 95401
- )
6'
<lb May 10, 1976 g,
g W %,s*'
2 V
s%' #
p*I*=, c.a 8'
(
Mr Victor Stello, Director Q/ >,
Division cf Operating ".eactors c3 y
7' N<'
U S Nuclear Regulatory Commission Washington, DC 20555 Ph,'
Dear Mr Stellos
/i f"i hyl$
a
,. e
MONTICELLO NUCLEAR GENERATING PIANT Docket No. 50-263 1.icense No. DPR-22 v 5
In-Plant Safety Relief Valve Test
~
The January 6,1976 General Electric letter from Mr Ivan F Stuart to Mr R S Boyd U S Nuclear Regulatory Commission described an In-Plant Safety / Relief Valve Test to be conducted as part of the long tem program for evaluation of Mark I containment systems.
Northern States Power Company has agreed to the perfomance of this test at the Monticello Nuclear Generating Plant.
Instrumentation essentially as described for purposes of this test has been installed at the Monticello Plant.
We now anticipate this test will be completed during the week of May 13. 1976.
In order to obtain meaningful in-fomation with relput co'the test Qjectives, the testing must be perfonaed under conditions wherein the pr(pure between drywell and torus is equalized.
Present test plans indicate that containment pre-ssure equalization will be required for approximately four days for the conduct of the test.
The pressure differential will be restored after completion of the test.
If the test sequence is interrupted for scheduled periods in excess of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the differentint pressure will be restored during the interruption.
Our February 6,1976 letter to you provided the basis for continued Monticello operation with respect to results of *he short term program then availablel this letter briefly described certain structural modi-fications being considered.
Based on further infomation and evaluation, and in view of the longer interval required for implementation of structural improvements, Mark I owners met with you in Bethesda on February 26 to discuss operational measures which could be instituted promptly to enhance safety margins by reducing potential loads.
Mr Rusche's letter of February 27, 1976 summarized that meeting wherein Mark I onvers agreed to establish at least a one psi differential pressure between drywell and torus.
Our March 1,1976 letter to you confimed that NSP would establish and maintain this differential pressure at the Monticello Plant until other appropriate measures could be instituted.
9102130392 760510 g-PDR ADOCK 05000263 PDR p
ae NORTHERN OTAVED POWER COMPANY Mr Ytetor Ste1.lo
-2 May 10, 1976 1he structural modifications were discussed in further detaf f with your technical staf f on April 9,1976
'Ihese modifications and their evaluacion are represented in detail in the attachment to t.iis letter.
These modifications will be completed prior to equalizing the con-tainment pressure dif ferential for perfoming the s&fety relief valve test.
Information in the attachment shows that safety margins with the modi-fications installed and the dif ferential pressure removed for the con-duct of the test are actually enhanced in comparison to pre-existing conditions with dif ferential pressure prior to any modifications of the structu re.
Further, conditions under which the test is to be perfomed will provide safety margins conservatively within and con-sistent with the margins of safety discussed in Mr Rusche's letter of February 27, 1976.
In surinary, the test is currently scheduled for the week of May 23,19/6.
The structural modifications will be completed prior to perfoming the test.
Containment dif ferential pressure will be restored af ter completion of the test.
Yours very truly, h.
L 0 Mayer, PE Manager, Ntc lear Support f arvices LCM / LLT/ deb 4
cc:
J? Keppler G Charnof f MPCA Atto: J W Femaa
ATTACHMENT C
Our February 6,1976 letter stated that NSP had undertaken a course of action to " develop detailed engineering designs and determine the feasibility of installation of these designs for modifications to improve the structural elements of the torus support system that are subject to high loadings". We further stated that NSP was prepared to discuss this action plan at NRC convenience.
On April 9,1976 these modifications were discussed in a preliminary way with NRC Staf f personnel.
The attached documentation, consisting of drawings and tables, was presented in that discussion.
The modi-fications described by these documents are currently in progress with completion anticipated on er before May 21, 1976.
The table entitled " Summary-Downward Loading Phase", illustrates the substantial improvement in safety margins resulting from these modi-fications.
The ratios of load to ultimate capacity show that the modifications produce a 46% tmprovement in margins without drywell pressurization over the pre-existing condition with drywell pressuri-zation. A similar comparison for up-loads shows an improvement in margins in avcess of 100%
These modifications represent completion of the action plan discussed in our February 6,1976 letter.
{
UNITED STATES NUCLEAR REGUIATORY COMMISSION NORTHERN STATES POW'ER COMPAhT FONTICLLID NUCLEAR GENERATING PIANT Docket No. 50-263 License No. DPR-22 LETTER DATED MAY 10, 1976 RESPONDING TO NRC REQUESTS FOR INFORMATION Oli CONTAINMENT DESIGN Northern States Power Company, a Minnesota corporation, by this letter dated May 10, 1976 hereby submits information in response to NRC requests for information concerning the Mark I Containment.
This request contains no restricted or other defense informatio,.
NORTRERN STATES POWER COMPAh7 By OMsN)
L J 4G(chter
~
Vice President, Pwer Production
& System Operation On this 10thday of May 1976, before me a notary public in and fo-said County, personally appeared L J Wachter, Vice President, Pwer Production and System Operation, and being first duly sworn acknowledged that he is authorized to execute this document on behalf of Northern States Power Canpany, that 1e knows the contents thereof and that to the best of his knowledge, information and belief, the statements made in it are true and that it is not interposed for delay.
, JAJ A-D' N
DENISE E. BRANAll l
IIDTARY PU3UC-MIMflE30TA HENNT.rtM COUNTY l
l; Mr Comminion Emphoe Oct 10,1981 j v m m m.....,...
NSP-01-052 4}9l76 27 '- 8 I.D.
/
e,o.sc f
.sJ
/
./
/ f
, / f/ '
[ (,
_ /.
- 3 e'
1 dj
/N,sj
\\
_._ / /
ss.
a m
-1 1
_L I
_L_.
w v
4 c-
.e 8
s i
N M
clS$$$[h
[7--ouisics r
/
,JQ "*'
t o.sec 49'-0 TO 4 DRYWELL f
FIGURE 3.1 -l h10NT CELLO COMPOS!TE SECTlCM THROU6W SUPPF(GS$!0N Cl-IAM 3.6 nutech
NS'.' 01 052 i
\\.
a E
1 4
1
~
i ADDED 160 SES.
o, 10,,@ PIPE..
=
i P.EINP. SOH. 140' 4
EXISTING 6"% PIPE 4
N
. \\
~
\\'
s t'.
u j
~
N/
Nk N
I i
/
s/
/ /'s%
'\\
t
-/
/,
INTERMITTENT V/ ELD l
COLUMN REINFORCEMENT I
J Figure 4.1-1 8
l l
nutech 4.3
J.
use-vi-u u a
6 l
- PlPE COLUMN
.s j
T
's.
a j
es l
N sNy
'. ~ -
g l
N'..
f////;/
,/
l'. :l-N'N%
N 5/ '
yQ
, s\\
BEA.71NG WEDGES aLocK-x Tv.A N g %), g/
M('
/
l yg N
N\\\\
t l
COLUMN PIN CONNECTION RE N FORCEMENT f
Figure 4.2-1 l
1 l
l l
I I
. x.
-7
~_
Nbt*-ut-uus TABLE 6.0-1 blat ERI,a (3 PROPERTIES b1INIh!UM YIELD BLIND 1Uhl ULTDIATE MATERIAL STRENGTH (ksi)
TENSILE STRENGTH C-1018 40 60 A-106-GR B 35 60 A-36 36 58 e
A-283-GR C 30 55 A-615-GR 75 75 100 A-516-GR 70 38 70
. API-5LX-GR X42 42 60
. Pins C-1018
- Existing Pipc Columns API-5LX-GR X42 Pin Connection Clevi.-
A-283-GR C
(
A-106-GR B Colu a Reinforcement A-36 Existing Anchors Reinforcement Anchors-A-615 -GR 7,5' A-516-GR 70 Pin Support Cradles A-516-GR 70 Pin Support Wedges Anchor Plate Washers -
A-36 l
l l
nutech
- e
nur-vi-vai e
TABLE 6.0-2 ACTUAL COLUMN
~
MATERIAL PROPERTIES Column Yield Strength Ultimate Strength (ksi)
(ksi) 73.2 Inside 43.1 Outside 50.5 82.5 i
Column material is API-5LX-GR X4 2 nutech 6.3
NSP-01 052 It was the design reports for all Mark I. plants.
concluded that an across the board value of 0.80" would be reasonabic for all plants.
Using the Bechtel method but utilizing the actual yield strength of the matericts vs. the minimum specified y.ield, and utilizing a preliminary plant unique analysis to arrive at an upper bound for the column eccentricity (6), the following values for the ultimate column capacities can be computed.
Estimated Ultimate Column Capacity (kips)
Inside - Existing 889.
Inside - Reinforced 1606.
Outside - Existing 1282.
Outside - Reinforced 1753.
~
i TABLE 6.1-1 i
COLUMN ULTIMATE CAPACITIES Upward load ultimate capacity is. presented in Tabic 7.2-1.
The capacity is the column cross-sectioned area times the material ultimate tensile strength.
Actual naterial proper-ties of the existing material is used.
Upward load capacity l
is controlled by the strength of the pin / lug base connection.
~
Refer to section 6.3.
l l
nutech 6.5
NSP-01-052 P
\\I
- NM y-g ph.q_gs v-l I
I I
l Figure 6.2-3 l
6' gI EXAGGERATED COLUMN I
DEFORMATION l
i 1
-c V
-K_
v...,.
mO P
the following categorization of From Figure 6.2-3 above, stresses can be made:
Stresses Resulting. rom
'Cate gory h
(axial load)
Primary P
ggsa x6 (bending along Primary P
cosa the column)
Secondary i
M (bending moment l
at top of column) l Table 6.2-1 I
CATF.CORIZ ATION OF COLUMN STRESSES
\\
nutech 6.9
NSP-01-052 e
i_---
m p*
g
$5 N
N D
..c 4
0 Q
g 5E N
N D
n n
_t 9
9 a
- t.,m U
C
- c. 3 w
m EMU 9.
b M
n ca 2M T
Y
~
g 52 6
e
=
m
'$- D "d
Q T
^
a w e =g:"
g s, s t.
m n
g t (V >m-G t
h
$ 4 k
9 9
7:'
N u;
8 m,
o o
=
m m
A.
m e
+
~
x
.{
k v
_E C
t T
,i inic' e
O
'U f
Q NlN 5
Q y
x h
3:
is g
$ $ P-7 W
E8E!
fd
[
'uU 4-o e
g 1
_l 4
x 4 eh N
[ 4 sa, 8
g i
u p
8
+
w N-N-
-g ea 1
g F"
g a g;
=w 8
8
{
.=,
ea s
se ns 4
=
x, 3
l 3 Z
,1 g
C M h
-El b
6 0
$ >8 ca n
? D 5
5 N
N
=
W v
g 8
>- e Es N
8 E
9 P
F.
t zu m
n m
g x
E 5Y C
9 E
D Eu N
N W
=d 9
'X.
x rd D
Ea 8
~, hi O
T r--,
Eh Y
h hD E
8 N
yi 9
g Ej 3
N E
D<
l
^
a
~
3 m
0 m
e c
7 0
i 4
.i a:
to m
6
-r O
N E G ff's J.
4 W
ed r0 Id og 8$
O hW 9
9 i
{30 p* E m
gs aa c
e L.3 2
2
<u
'A er n
O H Y Q E
5 E'nd
.A f5 Y n r -:Nm 0 F :NmE o
y, h
O4
( tn in W (@t0 TV WG
+
t--
E s
2d 2d O
M s
9" E6 nutech
4 NSP-01-052 7
e 4
Q t @Is
('
m n
}2{
@9 Q
+
o
.o f =
Z t e 5 *
- O 5
x
- a. c W
e z X @ a
+
o tu s
s e
~
D
-Q
. 6./ O, 4-Ll.
,d tN N
OZ
-F W
4 4
e2 g 64 e%
e o
e 41 tu wh e
+
n e
4 g
to O
O q
- g Zww C+m *4 2
NW C @e.
r
- amn c
2 z
-ee a,r--
Z D. < z w k
b ON y
R$ s.: b b C @Q 3
3 W'5%>
E g OO h 'd.; g @- < -
E%
(
+
m m
e e
t m
a 2
2
- 2. x' t rs m 5
F-ca w 2
2 NZ sn o
._J w El d
.>S it a
u W<
Q C.)
M M
J 0
E b
O k8 d.
J Z
LU LA.
u.
2 W
9, @
ul W
p
)
- a D
1-O s a a
2 H 2
O O
66 N
s 2
i i
rm OLJ r
nutech 6.14
NSP-01-052 s'
TABLE 6.3-1 PIN CONNECTION CAPACITY CRITERIA TYPE Of STRESS CODE ALLOh'ABLE ULTIMATE Tension at Pin Holes 0.4 5 F 1.0 Fu y
0.4 F
F/
u Shear y
0.9 F
1.0 Fu Bearing y
0.75 F 1.0 F Bending y
u g
k r
I 9
l l
nutech 6.18 l
NSP-01-052 TABLE 6.3-2 PIN CONNECTION PROPERTIES s
ITEM EXISTING REINFORCED 15.00 in 36.77 in' t
Bearing Area 8
12.27 in' 12.27 in Pin Section Mod.
l Pin Cross-Sect. Area 19.63 in' 19.63 in' 8
11.82 in*
- Clevis Tensile Area 11.82 in 2
8
- Clevis Shear Area 13.26 in 13.26 in
- See Figure 6.3-1 for failure planes 4
e I
nutech 6.)9
NSP-01 -M 7
. i s
TABLE 6.3-3 PIN CAPACITY (loads in kips)
CODE ALLOW:
ULTIMATE CAPACITY STRESSES CAPACITY w/
Fix w/Fix w/o Fix w/Fix ES Bearing 907 2584 446 1265 Bending 1000 N/A 500
.N/A Shear 1496 N/A 691 N/A J.
e i
e e
9 h
nutech 6.20
NS P - 01 0 T. 2 1
TABLE 6.3-4 CLEVIS UPLIFT CAPACITY (loads in kips)
TYPE OF ULTIMATE CODE ALLONABLF.
STRESS CAPACITY STRESS CAPACITY Bearing 907 446 Tension 650 176 1
Shear 463
'175 nutech 6.21
O NSP-01-052 r
i Figure 6.3-1 CLEVIS FAILURE PLANES A
t' GHEAR FAILURE
/
PLANE i
i i l I
I I,
"l l'\\#
s.
7 -- -
N
,1.s
\\
-TEN 51LE FAILURE PLANE v
l' nutech 6.22
NSP 01-052 FIGURE 6.5-1 COLUMN CONNECTION h1 7.--
eh
/
m
/.
$ 7
.?
{%
r,jk
+
/
\\
E T,
- 4. -
i 6.2s 11Litech
+n-hm.
A a1-*
1
.4 4
md
- <_aw14_-
m mddi eeoJ-A a.,#
.,e a4
__.4+,.-4-n4_1
_a_.E--.
a.e.it&.
L 4d.
h 4m 4 a2c-a m.__Us A_---n._m 4
l g
f, N
EW2 dEM W
m g 3+g.. e e
p y
s a
c g
a J
4 O
6 g
m Q
3 e
=
g a sg m
% le hl 8
4 8!
R l
=
a
.h.
5 E s-Q 4
N.
X R
W
=
3 u
4 3-o y
k gkl '
l I.
=
g 8
8 it h
g 33 y
20 e
o e
o m
o s-4 8'R s 3 'E c4 19 0
O tD e
n.
a V g; Q
U h
9
.N P
d
?
~
e 4
t b
d b
6
=
g a
r.
e y
n r.
e 38,m o
U L
W 10 En'd s
o t-4 c
m coE Eh e
s r-.
'f m
e-d Esh 8
8 8
g R
e:
3 n
F-2 3
3 4
c o
$ o.{J%>
I 3
} qdd o
m 2
8 8
o lE 2
We8 sggb e
e a
w e
g
/
r r
r a
5 s
y sz a
- E d
Ea@
O N
e4 N
~
m p
M{m gs_
tY.
Pn t%
'5 8
"3 a
q]
9 s
a8.
n n
n e
a e
z 3
g r
r r
=
u e
e a
hlh+!
- 2 3
2 3
0 3
ggs 00g"gg e
e m
m 2
4 e
gg e
e s
y a
h W
W W
dv ogg
-g y
gg e
v 4
dutech 7.5
Ph5ED &f l "!* *
[2AT10G $LOADSAfLf0U/T6 /
~ Ta sI_a 1.2.t
SUMMARY
~ UPWARD LOADING PilASE (1.0 ADS It1 KIPS)
C/AMM/pl l
l l
11 ti 12 l s l ta l ts l to a
- s
{
n 1
2 3
4 l' S l
1
-s l
s 1
CODE ALLOW.
RATIOS OF LOAD TO CAPACITY p
DEAD SE!S-OfNAMIC TOTAL 40AD WITIMATE E
STRESS LOAD MtC PCOL SWELL G POOL CAPACITY ULTIMATE CODE ALLOWABLE u
l WI.TER LCED LCADS SWELL CAPACITY V TH-WITH WITHOUT AP WITH AP WITHOUT AP W.TH AP Y
WITH VERT Y
~
WITH STEEL WITH-WITH CT S
ValH-WITH ' WITH-VATH WITH-WITH WITH.
WITH ND.
Fix OUT Ax Ax OUT Ax nx CUT Ax Ftx OUT RX Fsx 5
1991 16l St9{
200}
200 161 1926 3376 bOf 1103
.10
.06
.08
.05
.29
.37
.24
.14 i
I.S.
COL i
135}
16 i 319 4 2004 200 161 463 463 175 17 5 43 43
.35
.35 1.14 1.14
.92
.92 t.S.
r i
I 3
SHELL 13 5 )
16)
S19 ). 2801 200 161 2568 2535 7G5
'765
.oS
.08
.06
.OG
.2G
.03
.21
.21 f
1.S.
CONN.
135}
161 3191 2005 200 161 1E0 620 i.7 287
-l.Il
.92
.99
.26 2.99
.70 2A0
,sG IS ANC aS.
165}
'20t 389) 543) 244 19 8 2&l2 3064 1044 1353
,C9
.06 07
.05
.23
.Is
.19
.15 l
1 3
COL t
I I
i 169}
'201 5891 343i 244 196 4 63 43 175 17 9
.53
.99
.+3
,43 1.39 i.39 1.13 t.is i
0.S.
7 I
l pw p c
e j
3 SHELL 165}
goj gg?j 343j 244 19 8 2SG6 256.9 7GG 7G5
.10
. !O
.0S
.08
.32
.32
.2G
.26 QS.
l l
CCNN.
-g
.92 s.64
.Ss 2.*
.69 m
16sj 20t 9 91 343i E44 iso 180 620 67 es7
.l.36
.39 1.10 1
G o.S.
o.,sc I
O i
. nc, v. y i g i.,
v s. toucu An ni out^ivin s u c.: evN oute i Nuvoi n
___ d 9_ '. 2 b.3____
M
' NilC DlSTilll!U1lON ron l'AflT 50 000KET M AT Elll AL I HUM; DAtt or occuutNt 10-u-
N:
' r r-N.
- 3. t r i. ,
s.r..,
q,,
- ,,, i '
g.
te:
D AT L fit Clivi O 5 - 1 '.' - 7 t, s
C L t T T t ti C 4070H1200 P flOF INPUT FORM NbMDLit OF Col'Its fif CitV[ O C ostl GIN AL E UNC L ALT.lF IC O OCOPY ot :ic nip T ION E N C LO *.U R C
..- rs 7 1!r tn Ft(C dtJ l - t ',, f '... '
.a r.a
!g..e
' ' I ' * *' M ' i 5, I r - P l m t ' t i ! Y dC1dUI f 01 ' ' ' 1 " '
i'I tu tinc......('.o cy. e r. c ' rec'd)
.e
\\
.[
~
l TLA!TI NAME:
b 4.15n i OR AC TION / int:O R.' AT ION 1.NVIn0 3-14-7ti ch:
1 1
ASSIG:h:D AD :
l ASSIChT:D AD.
[ EPANCll Ci:I:~.:' :
egg fr 4,,,s BRA::Cl! CHIP.F ;
[ PROJi CT 1:. NAGER:
,$ n o e / c,,
I l'ROJ:'C'I 1:ANAGER :
ff LIC. ASSI. :
f7, g
LIC. ASST. :
I I
IN1 EHN AL DISiillBUTIO:1 Mm-ri1 i' N
._.C_S.y siti' 'S__sA[!:n
__I __ buid._sy31sts
__r;;y.tng _73c t
/t NRC PDR
.j _j_!!nn; sum
[_1EDESCO
__EIlb'ST
/'
I6E b_
l sci!R0"I.U'1 ULNAROYA
_j_II ALT. A 7 D
/_l _ QE_T,D L'. I :AS SPA!'GLER
-/
GOSSICK & STAFF E;;cI!;J'gRIpO__
IPPOLITO
____.MIFC. _
!!ACCA:2._
L _ _ ____
_ SITE _TECli
_ g_CA;;y KNIC:lT OPERATII:G nrACTO';S CAIOllLL IMUAR:R SIINi:I L STEl.LO STEPP
__ _11ARLP,ss PN!!.ICKI ntrIMAN OPEDATING TECl!
l PROJECT !!ANAGE:' :I:T n!: ACTOR SAPETY
./
EISEMittrr SITE ANA1' ISIS 1
BOYD COSS
/
SCAO VOLLMER l
P. COLLIllS NOVAR
/
PAEg BUNCil 8
l!OUSTON ROS7.TOCZY
/
SCll'. CNCER J. COI. LINS PE'iERSON CllECK
/
C R n'E 9 EREGER
!!ELTZ lil:LTt:!!ES AY 6 I SITl'. SAFETY & 1:NVIRr SKOVil0LT Al.T7!!A N A N Al.Y S I S 1 llTi'.1;l'C I.E; T O'! 6 Mir1,1,7it EX li hN AL ()lSlllll U llON C 44 ilOL fJUMULH
,/_1.PDI(;[d_12f_Jef efs A NATL. LAH IM OIAVF.N U.TI. l.All
.g_{_TTC RI G. V-II:
ULMIMUUN(URNL) lf
./_ _._NSJG LA PDR ASt.n CONStill: ANTS
~/.'~ wo(([ u.m p /crtr 7o td def ce
~
,