ML20005E544

Describes Actions & Insps Completed During Recent U2R15 Refueling Cycle & Proposed Schedule for Completion of NRC Bulletin 88-008 Requirements,Per Util 881221 & 890616 Ltrs. Extension Requested Until 900631 to Submit Data Evaluation

ML20005E544
Person / Time
Site:	Point Beach
Issue date:	12/29/1989
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-89-169 IEB-88-008, IEB-88-8, VPNPD-89-689, NUDOCS 9001080099
Download: ML20005E544 (6)

Text

g + w - -

u: o .

~

~

l0 ,

s; '

f gm+

e i ac :

n >+

'% e. Wisconsin Electnc

' POWER COMPANY '

l

- 231 W Mchigon, Po. Box 2046. MAm: vkee. WI $3201 (414)221 2345 VPNPD-89 68 9 -  !

.. ; . NRC-89 169

" n. '

, _ December 29,.1989 li Y Document. Control Desk U;-S..~ NUCLEAR REGULATORY-COMMISSION

~

l Mail.Stop Pl-137 <

Washington,'D.C. 20555 I

f ' Gentlemen: .

1 l

DOCKET NOS.-50-266 AND 50-301 1 '

iL 4 ADDITIONAL RESPONSE TO BULLETIN 88-08 L LTHERMAL-STRESSES IN PIPING CONNECTED TO' REACTOR COOLANT SYSTEMS L

~

POINT BEACH NUCLEAR PLANT UNITS 1 & 2 j  !

) ,' 1 Reference'1)

. WE letter VPNPD-88-480/NRC-88-089 to NRC ,

dated September 27, 1988 i 2)- WE' letter VPNPD-88-616/NRC-88-128 to NRC I dated December 21, 1988 '

3) WE letter VPNPD-89'340/NRC-89-074 to NRC 1

L dated. June'16, 1989 '

! Referenceil' identified piping which had the potential to be sub- l jected to stresses from< temperature stratification or temperature k . .occillations which could~be induced by leaking-isolation or check- '1 '

Lvalves. .We-evaluated the piping in'accordance with the criteria presented in'NRC Bulletin 88 " Thermal Stresses in Piping

. Connected to Reactor Coolant Systems." The: lines identified were i

'the-two-inch diameter auxiliary charging piping and the two-inch diameter auxiliary spray piping of both Unit 1 and Unit 2.

j

. Reference. 2 provided results of the Unit 2 inspections and described

'.the temperature monitoring equipment installed, data collection system, and preliminary information regarding temperature distribu-tions in these lines.

Reference 3 provided results of inspections and actions taken on

'these two piping systems during the Unit 1 outage completed in 1 April 1989. Further, it provided a description of our plans and schedules regarding evaluations of the data being collected. t

s. - .

f

~

Ohh66 PDC'

,6/ 0 il subsMm' ofIllurmshi lhtyyy Cupiratsw l-s 1 Y}

y

^b

. Document Control Desk December 29, 1989 l

Page 2 i

This letter describes the actions and inspections completed during the recent U2R15 refueling cycle, and provides the proposed schedule for completion of IEB-88-08 requirements.

Reference 3 indicated that an evaluation of the thermal stratification effects recorded on the Unit 2 auxiliary spray line (as described in the bulletin) would be completed by December 31, 1989. Subsequent to reference 3, the evaluation of the collected temperature data was deferred pending an inspection ,

of the thermocouples (TCs) during the U2R15 refueling cycle in October 1989. There was doubt as to the validity of having a stratification level approaching 300*F in a pipe with an inside diameter of 2.626 inches.

It was suspected that the bottom TC was not in contact with the outer pipe surface and was indicating temperatures well below expected values. In addition, there was suspicion that the top TC was not in contact with the pipe because the recorded temperature data did not reach the expected operating temperature of that line. We therefore believed that the TCs were actually measuring the pipe insulation temperature. Since it was possible that the recorded data was invalid, we believed that a visual inspection of the TC installation was warranted.

Visual inspection of the TCs revealed that the spring-loaded TCs originally installed (see Fig. 1, Attachment 1) may not have been in contact with the outside surface of the piping. We replaced the bayonet TCs with clamp-on TCs (see Fig. 2, Attachment 1) to ensure that contact with the outside pipe surface was maintained. In addition, another set of TCs was installed on the adjacent spray line to define the thermal stratification profile in the line, (see Attachment 2 for the TC locations).

Temperature data has been collected for plant heatup following the Unit 2 refueling outage and is currently being collected during steady-state full power operation for analysis purposes.

The new temperature data indicates that thermal atratification of up to 300 F does exist in some of the auxiliary spray piping and ,

to a far lesser degree on the spray line (approximately 30*F).

This indicates that the large AT covers a very small portion of piping. The new data also confirms the presumption that the TCs were not in contact with the pipe. The data now indicates temperature readings closer to the normal operating temperature of the pipe and more closely matches the temperature variations expected in the line during heatup and steady-state full power operation.

s -

, \

r

• i m  !

. bocumentCort-olDesk f December 29, 1989 Page 3 .

We still intend to perform an engineering analysis of the ,

r recorded thermal stratification in order to verify code  ;

acceptability of the piping when subjected to this loading

• condition. However, the evaluation of the new valid data now  ;

being collected will mean that our commitment to complete the .

analysis.by December 31, cannot be satisfied. Accordingly, we  ;

request an-extension to June 31, 1990 in order to complete this ,

F evaluation. We will provide the NRC with the results of the L. analysis and our final response to IEB-88-08 at that time.

Please contact us if you have any questions concerning our actions in this matter.

! Very truly yours,

( i t!Y6 l ff C. W. Fay Vice President Nuclear Power Attachments r

5 5

I . 4 i

i k

i ATTACHMENT 1 -

Q  ;

-v-- i' = - 3-w w -

m. ,. . ..

y  : 2g , -

W. .=..

_q ._ m {d  :

FIGURE 1 - BAYONET STYLE THERMOCOUPLE i

l m -- -

7 3-7 g}

/ i

-4 N

^

r FIGURE 2 - DIRECT PlPE CLAMP THE_RMOCOUPLE L

l.

L Page 1 of I r

' - - r- - - - _ - _. , . . - , _ _ _ _ _ _ . _ , _ _ _ _ _ , , _ _ _ _ _ _ _ , _ _ , , _ _ _, , , , _ _ _ _ _ _ _ _

.c

• 3 THERMOCOUPLE

• Y MEW LOCATION PLACEMENT

+,*e #d[* c ng '1 SEE DETAIL 1 C+o . O* (TOP)

S@ .l 90" kg NIi I i /

LOCATIOtt 1 SEE DETAIL 1 #,1 -

-4 i O,8 180" -1 DETAIL 1

'A ,#~'b E f ) .

~

s./

g -

y t DELETED n ff

)I h h PRZ CUBICLE FLOOR MXEFTATUK PRESSURIZER SPRRY r & RUXILIRRY SPRRY nRTERtpL: R-376 TP316 MenIMRt. TMICKMESS: 0.138 ,0.331 ,O.394- ., j e '

REFERENCE ISO: SECMTELP-243, HEST.663hn,G18iR $ l REFERENCE P&I0: 541FM45,685Jt75 m  ;

E

~ t

--;--____._,,. ~~~~~"~~~~- " -

I Page 2 cf 2

.' ' ' . ATTACHMENT '2 c- N x W  !

A=C

?

a b "A 5, l S

w s v l

~

D '

6 ~* \ e E*  ;

1 ,

+,

f v. b  :

,W. '

~

~

0 5,

.- 6 s g  %.

[%J La  %,

. - 4g - -

c

" ).

i e, .

, ~%

i

~

g\Q Yft .

1"s A NA a

s.

i .

n b. '

ci,,

• k

~ ~- N *e'.Y 79

./ p'4

~9/ e6

&u%.

's

/7

. .. _ . . _ . __ . . . . _ . _ _ _ _ _ _ . _ . _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ _ _ _