ML20066C533
| ML20066C533 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 01/07/1991 |
| From: | Vaughn G CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20066C535 | List: |
| References | |
| GL-90-05, NLS-90-266, NUDOCS 9101100247 | |
| Download: ML20066C533 (11) | |
Text
_ _ _
3-
]
o --
N cwonna Poww a usht company P.O. Box 1661 e Rele$gh, N C. 27802
- SERIAL:- NLS-90 266--
JAN 071991 10CrR50.55.
G. E. VAUGHN V6ce Preoloont Nuclear Services Department l
United-States'Huclear: Regulatory Commission ATTENTION: Document Control Desk' Washington, DC ;20555l BRUNSWICK STEAM ELECTRIC-P1 ANT, UNIT NO. ' 2 DOCKET No. 50 324/ LICENSE NO.iDPR 62 ASME CODE r? LIEF REQUEST
- SERVICE WATER' Centlemen:
In accordance'with 10_OFR 50.5Sa and the guidance-provided.in'Ceneric i
Letter 90-05, "Guidanco For Porforming Temporary Non Code _ Repair Of ASME Code.
l Class 1, 2, And 3 Piping,"-Carolina Power & Light Company hereby. requests a relief from the requirements or the ASME Boiler and--Pressure Vessel-Code,_ __
Section XI. for the Brunswick Sceam Elset.ric Plant,-Unit 2. On DecemberJ13 1990, a small throup,h-wallileak was d!.scovered on-the Sarvice WatercSupplyf Line to Diesel Generator No. 4.
- A temporary repair consisting of rubber ganket material secured by mechanical cisps c as _' installed to prevent further -
w leakage. contains a relief-request which justifies use.of-this temporary non code repair __-until-a-permanent, code approved repairgcan'be implemented. CP&L will perform the permanent _ repair during the:next Unit 2, maintenance outage, currently : scheduled to begin on _ April 13,~ 1991.
Please refer any questionscregarding this submittal to Mr.
M.- R.-Oates at (919) 546 6063.
-Yours very truly,' _
y
..C. E. Vaughn-CEV/ MAT (948BMP) 6 cc:
Mr..S. D. Ebneter Mr.-N. B. Le Mr. R. L.'Prevatte 9101100247-910107
-apt /
1L //
PDR ADOCK 05000324 J;
- P PDR g'
//-~/ g
a piesel Generator Service Water Relief Recuest SYSTEM:
O'rvice Water (Supply Line to Diesel Generator No. 4)
Camponent; The 8" X 6" reducer on line 2 SW-234 6 157 just downstream on -
inlet supply valves 1(2)-SW V213.
FUNCTION: This lina provides service Water to the Diesel Generator No. 4 Jacket Water Cooler.
CIASS: ACME Section XI, Class 3 REOUIREMENT: As mentioned above, this line provides service water to the Diesel Generator No. 4 Jacket Water Cooler.
The number 4 Diesel Generator is-required to be operable per Technical Specification 3/4.8.1.
If it is not operable per the action statement of the Technical Specification, a 7 day
' initing Condition of Operation (LCO) must be declared af ter which time (if
.perability is not restored) HOT-then COLD unit Shutdown must follow.
RELIEF REOUIRED: This request is being written to allow a temporary non code-repair of a through-wall leak on the referenced line.
The through wall leak was identified on the Service Water Supply Line (2-SW-234-6-157)- to Diesel Generator No. 4 Jacket Water Cooler, The leak was discovered on December 13, 1990, at which time a Maintenance Work Request for the temporary repair of the through-wall leak was initiated and Tracking LCO T1 09 2456 generated in accordance with BSEP Procedure OI-4.
The leak is located on the reducer referenced above in the " Component" section at the bottom weld no. FW B80B as identified on FP 9527 22356, Drawing No. 2-SW-ISO 40.
The through-wall leak is characterized as a hole approximately.25" diameter.
Based on past experience, it is believed that the through wall failure was caused by corrosion in an area exposed to the salt water through a flaw in the cement lining.
A temporary repair consisting of rubber gasket material secuced by-mechanical clamps has been installed to prevent further leakage. The soft rubber patch represents a non code temporary repair to be justified by this relief request.
Refer to Attachment 1 for a diagram of that repair.
BASIS FOR RELIEF:
P&ID D-02274, Sheet 2, and Spec. No. 248-117 indicated that line number 2 SW 234-6 157 is Class 157 (design pressure 80 psig to 150 psig and design temperature 103F), Group IIB, ISI-Class 3 and therefore the requirements of Generic Letter.(GL) 90-05 apply to. any repairs performed on this piping. -This request is based on the guidelines set forth in that letter. Those guidelines will be spelled out in subparagraphs listed below I
with appropriate action by CP&L listed:
t 1.
Document the character of the flaw cited - An Ultrasonic (UT) Non-Destructive Examination (NDE) was conducted on December-13, 1990.
The actual through wall leak is characterized as a.25" hole with localized wall thinning adjacent to it along a section approximately 4 1/2" included as an attachment to this relief i
request (See Attachment 2).-
+
2.
Assess the structural integrity of the flawed piping by -flaw evaluation.
Evaluate for the design loading conditions - the visual and UT NDE examinations were evaluated for structural integrity by the Nuclear Engineering Department (NED) Structural Engineering utilizing the "Through Wall Flaw" approach as outlined in GL90 05.
NED concluded that the'1eak did not reduce the structural integrity of line 2 SW 234 6 157 and the line satisfied-the-criteria of the "Through Wall Flaw"- approach 1(SeeLAttachment 3 for calculation 'which justifies that use of this piping through 1 full year of continued service.
This takes into account wall thinning at the rate of.020" per year-(stagnant condition, that being the normal condition of the water in this line).
3.
Assess the overall system degradation by an augmented inspection.
(5 needed)
These are attached (Attachment 4).to this relief request and are all acceptable by minimum. wall criteria as sett forth in the minimum wall calculation found in Attachment 3.
Inspection locations are shown on Attachment 1.
All.inopections were found acceptable when compared to che.053" minimum thickness t
called out on page 3 of the referenced calculations.
4, Assess the integrity of the affected piping at.least every 3 months by a suitable NDE method (UT.or RT)
A UT NDE will be-performed on this piping every 3' months until the permanent fix is installed.
5.
Perform a periodic' qualitative assessment of leakage through;the temporary non code repair - Weekly surveillance has been scheduled to monitor for leakage from this pipe:in accordance with Generic Letter 90-05, 6.
Determine the. impracticality of performing a. code repair.- Due' to.
the location of the through wall leak and that Diesel Generator; Nc.2 was inoperable at the time the through-wall leak was'..
discovered, a unit shutdown would have been required to perform a permanent-repair.
Since Diesel Generator No.2 was-in a 7-day LCO concurrent isolation of Diesel Generator No.4.would'have placed
{
the unit in a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (to hotLshutdown)LLCO., The permanent repair could not have:been performed within a-12-hour period.. Since there were no operability' concerns that would have required unit shutdown, a temporary repair was justified.
~
Brunswick Unit 1;is scheduled to restart-from its present refueling outage in early February 1991.
The Unit 1 startup l
Auxiliary Transformer is presently out'of service,for inspection for 30 days. During this period if a Diesel Generator should be taken out of service;the unit would immediately be placed in a 12-
. hour LCO.
As-shown by the calculations provided the'non code repair will caune no' detriment.to the integrity of the pipe and in turn to plant operation?for the-next; year.
It would not be-prudent.to perform the permanent repair now as it would require that a safety system be taken out of service.to perform the 2
r i
repair.
CP&L intends toimake the permanent repair during the'next I
scheduled Unit 2 outage now-scheduled for April 1991'.
7.
Perform a root cause. determination The'through wall. leak on line 2 SW 234 6 157 has been temporarily repaired using a soft rubber patch.
Since the actual condition of the cement lining of the pipe cannot be determined, data contained in.CP&L Metallurgy Unit
~
Memorandum, MSL No.10-108.(Attachment 4) was used in the analysis.
NLS No.10108 addressed the cause of pipeLjoint leaks-L in ceaent-lined service water piping..The affected linetis l
cement lined service water piping. The affected line is cement-lined cr-
.n steel pipe.- The conclusion of MSL No. 10 108 stated, "Leakag the joint is due to the improper condition of the- _
1 cement
- .tng". -Based-on_ previous experienue it is' believed.that.
.~
the tb ough wall failure was caused by corrosion due to cheLarea being exposed to salt water from a flaw in th& cement lining in a'
combination with a normally stagnant water condition, This won't be confirmed until metallurgical examination is completc._
]
~
Based on the analysis of MSL No. 10 108 the_cause of:the coment j
lining failure can be described by one of more of the following:
j a.
Presence of a crevice between the base pipe and backing ring.
b.
Using porous cement for lining.(coating) the' joints after they were wolded.
Damage in the original cement lining adjacent to the joint -
l c.
due to the heat release during and after welding.,
't d.
Improper application of ;the. cement at the joints _' creating.
rough surfaces causing more severe, turbulent 1 flow at the-joints resulting in a-liner-leakage' problem-in this area, q
Ar'ter the affected area has been repaired. the-removed section of the cement-lined pipe:will-be sent to the CP&L Metallurgy' Unit for-i detailed examination.
4 i
8.
Consider : system interactions _(Flooding,i sprayinglwater ion.
i equipment, and loss of flow) -1The affectedLareazis located:Just:
above the grating over a pipe trench. The pipestrenchidrains, tic' 4
-together and are piped out to_theLintake channel. (Therefore if the. rubber patch should fail,. flooding wouldLbe, contained _by the drainage _ system. There-is-no equipment (such~as-electrical.
L equipment) located adjacent 1to Ethe.-affected areas ?that could be -
damaged by. spraying:of water should theirubber patch fail. 'The 3
i
. Service Water System'is-capable-ofJsupplying flows greater-than i
required for_ proper coolingc(>350 CPM) Land therefore the amount of-1 flow.through the 0.25" through wall' leak =willinot. impact operation of the Jacket Water Coolerfshould the rubber _ patch. fail.
3-E 4
....,L
-..,p.
c.
i 9.
Schedule implementation of permanent code repair A permanent repair shall be implemented by the end of the ney.t scheduled Unit 2 outage, now scheduled for April 1991.
The repair will be made before that time if the 3 month UT.RT finds that.it is necessary.
The permanent code repair will consist of replacing the 8" X 6" reducer and the spool piece directly beneath it.
10.
Assure that the temporary non-code repair will not affect the structural integrity of the affected piping and must be reversible - As a temporary repair, the through wall leak will be sealed and maintained to contain any leakage until a permanent repair can be implemented. The temporary repair of the leak will consist of a soft rubber patch.
The soft rubber. patch attached by clamps (See attachment 1) does not alter the condition of the affected piping and is reversible; that is, the effected piping can be returned to the'as found flawed condition.
i l
l l
l l
l l
4 l
l
ATTACHMENT 1 RELIEF REQUEST NO.
B" LINE FLOW AUGMENTED: INSPECTION LOCATIONS EDG #1, at 2, #3,-L'#4 REDUCER 1/O" THK. X 6" WIDE RUBBER GASKET EDG #1 MATERIAL (2 LAYERS)
ADJUSTABLE in METAL BANDING '
_{
_g g FLOOR GRATING-Q ll l
4 6" LINE s
l ELEVATION LOOKINO= WEST i
SKETCH OF EMERGENCY-DIESEL GENERATOR:NO. 4 JACKET WATER COOLER INLET PIPING SHOWING 8" X 6" REDUCER.AFFECTED BY REFERENCED THROUGH l
WALL LEAK (NOTE SOFT RUBBER PATCH).
l:
THIS SKETCH ALSO SHOWS THE LOCATIONS OF T SUPPLEMENTAL ~UTs PERFORMED IN ORDER TO INSURE COMPLIANCE WITF
.dNERIC-LETTER 90-05.
l
E$R No.
n st - n
_90-0354_
nov, 'No, o
ATTACHXENT 2 -(cont' d)
D Pago No.
33 i
ATTACHME14T 2 APPtWDf! A RELIEF xEQUEST 110.
I THICKNESS CAllBRATION SHEET 0$
PtANT/ UNIT:
b#5 * 'M V L PRCCCDURI ?:~
4b6
__ ConPC@;7. _2$- 2 3 4.te.lg al
_ M V, - b CAtitRATio< etCCK ') _ CPL H1 'M
_ otc K THl0KN!5
- 2 Eb L S A EN I' /' 6 *0# #"W **h
_ SLCCK THtCKH65
- Lob - b}'t1 INSTRUMINT: k R * "k%t t 4 5 5' ' '?
a.2i' o$[
CAL. 0UE DATT: _1 + 2 9 i 3png ]
]1
.
- i,
$(RIAL HunSCR: 2 7 2 N
- h 8 91 SVEEP:
3I Ott,AY:
742 7D RANGE: -
O' T i
50 TRAN5DuctR FRIOJEN:Y: --f. 6 TRANS0WER $!R! AL Ho.: L 0 B EL I TRANSDUC[R BRAND-RO 4 WT Ec 4 TRANSDUCER SIZE: -
O' Z f TRANSDUCER ELEMENT:
SINGLE OR
{
0 lill lithilli 1111 Illi lill !!!1 till Illt lih 1 2 34 5 6 7 8 9 10
~
CALIBRA T10N EAdH MAJCA SCR![N DMSION: _d' O S "
VER. / CHECK CCrtENTS: _-
INi rlAt.
TIME Pib b R A w N r,,.
O o 2,2. ~14 A3 L 2)fo iST 2.
FP Da m+
2.7-3 r t.
Abt esi pso o s.w,a w o z. 7-14 Feet r,4r %f,co,feg W it L t> mo:
Fw - R <a e e,
~
EXAMINER 31 ObD-D ATE 3 Nt LEVEL
~
~
2-DATE
'REviba1RS 1
$M _ DATE.4'7*6-Ltvtt
[
]
2_.
-_ D Ait _
[
ADDrT10NAL SHtttS: h No
_ DAR
- l I
Page 13 of 28
e o
- s. '.
EER No.
__90-03542 Rev. No.
O ATTACHMENT 2 (cont 8d)
Page No.
M
'o NDEP-408 F
d 2
W e
$ 0 T~f'.
J s
y W 7 3 0
w N[y W
,~
c v g o
S y
2 N
d a q%
w
\\
3 W
Y e
t y 6, 3
3 gm.
77 9
s s 4 4 X
H j'g y
i Z
i s
w
)
h s
y p
N-i 5
kkk5 i
3 m
~
u N
O
.t~y.
3 3
u u
F ra b
d g
3<,
i I
M II kb ' &
l a
j c.6 8 '
- n.,
n, y
y y
~~
%g a3 m.o-o
.r 9
.a
~
- e. g r_
a t w
u t
b' d
J z
, 9
- b%qq me-W O
p m
34
,Q di J
,3 8e 4L b
~M c{ _
g E
og g
w
.a 3
-6 1
n.
a g
2y
=
". k 4
[
Y J
to lg s
9 9
N,.
_{]
h e' T 3
+h W
. q M.
~
4 3'
i bl,h y
.J b
A e
g
~~~m..
- n. I u
1 t
g f
.- :- T 08 l v a
e 6
p
- t4 h
n r
3 (D'
j - C 3
7 3 =l d e a '.s M.,
n.
n.
i E-2
=
~
~
~
r,
[
w Ih
- EE l
v ev k' "
D.
yo ri s
3 2 a.$ ed4-o L
g 4
j i
+
f
~
r.
EER-No.-
__90-0354
' ATTACID(ENT 2. 'Icont? d)
Rev. No.
o Page No.
35
^
~
NDEP-408 4
b
-t
.S h
7 8
i e
7
~.,
a a j
L4 2
=
i 5l3 1 t nf
}
2
~.
e y (
b:;.5%y ;
N 5
~
9 e
- ?;
s x
x g
s
. # 7 N T g
w 4,
b=
f 4
tJ T
6 Eg N.
e.
N.
N t!
-- a E
or 8y o
6 C
e, T,1..
7.,.
< '2 I
JN v 2
h s.-
4
. n. 7.r.
x 3
H gl, e
o
-@ g 3
' 4 *. $ k l i{n 0) 4,i 1
w,.s,
.r 6.
n i y J :o
-s t
m o
3d
'W Cl 0
.s 'o
-en m
,h U'g; N.
d.
fy 3
C!
k" '
H 5
og=
wbjn.
=
y 8-w t
c a
- e. u..
a g
yy q
- h 'o d
", h W
-4 J
gg 1
tMS (S.
1 w$a,,
i G
e a ene i
)
b
' d
,t e
a Y
0 e4 lp J
M Q' mm K Q*
N y
9 e
1 i
3 si _ng$~o.-
s,
,.. c_ 3 o.
c-z
- e.. ~.
r p.
l N
'E O
%,r o
re Eb*g h5 W
c a +. 0 ig4 4
.N'o.
o-03s4 ATTAC EENT 2 (Cont'd)
!~
c Rev. No.
o
~
PMJe No.
]
-...r...,.....,_,
g_ p aw,wc A T T Acu,txT i
y e o x e r S e s.a s w c e PASE1CQ i
,os wo.
44 w.r :D 3 30 4D eAit #M4
~
DRAWING J.J4"a'vT t
- 515iDd UE
$6094t w$A k.
2 9.isk L. 157 WILD /ffEW NM3CA Fo o w i.,
oost n s-t t t-i cw-BBoE FP 0"u AL3Sb P 5 r % o r t /-(
^
i:
er't4,s.3 sat
!!l O
Ditsas FI0W
%E.u th,ht t
b 8
C, 8; r TIM Lv L
Dem A 4seca.>
O c tu a n.v t. b t> g
]
C b t> c *: w i t r:
O,4 A.,T u.4, t b <. v 4 s Tit
__ F L.o w.
P L
.,a L V t E.W w ra b g
I8" 33, o,og" 84, o,o v
'S o.ot' 14,,.
o, g a
- 1,-
/
.' /
,, 7,.
/
/
/
?
l-
- l-b
/-
/
s y
4
/
i Rom-
\\
\\
\\
...o-
..u e,_ e
... u-
- e..e p.,c e.w.
H o t.E W
w a s t>
4
(
l Flod I
%D.3 l-l 2 ~ r4-~%
HDE CS I Rev. O G /63 f&ELu.kl' id/u M.sll$90
.7 y
i-e
, + -
q.
EER No. -
__90-0354 ATTACHMENT-3 Rev. No.
O RELIEF REQUEST NO.
Pago Ho, 24 CAROLINA POWER & LICHT COMPANY OPERABILITY REVIEW FOR f>flod$dck j
Ugg-2
-(Plant) 8 dAch51~ _
ATER (System)
EVALUATION ID NUMBER:
2
- IDN 4
- 2D SAFETY CLASSIFICATION:
N SEISMIC CLASSIFICATION:
( CODE. CLASS 3 -
-i (IE p METHOD OF EVALUATION UTILIZED: dTHOD' 1:
-SPECIFIC ANALYSIS / TESTING *
' METHOD 2: SENIOR STRUCTURAL REVIEW-PA VAIIDOWN' TEAM:~
__ A. 4.
upt -
M.S.A.ve>v,,o
~
9 APPROVALS:
-(Method 2 Only) h 3r the eka d_
_Inrinear
' Approved Proj ect i
Prines ne l' Enn Discipline-
~
j
_ f). v Phib
_ glA _
gQff Manneer g.\\s -Q o '
17 IS*-?O -
~
s 9
_-_-.___-__._------2-----
- - - - - - - - - -