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C OLn g @ CCgilpagly B;lg,gev %c w=
C OLn g @ CCgilpagly B;lg,gev %c w=
sewt mwnm P e N ew Gw4                                                     =4? unm November 7, 1988 U. S. Nuclear Regulatory Commission Attn:   Document Control Desk Washington, DC 20555
sewt mwnm P e N ew Gw4
=4? unm November 7, 1988 U.
S.
Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555


==Reference:==
==Reference:==
Beaver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, License No. DPR-66 BV-2 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09 Thimble Tube Thinning in Westinghouso Reactors Gentlemen:
Beaver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, License No. DPR-66 BV-2 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09 Thimble Tube Thinning in Westinghouso Reactors Gentlemen:
This submittal is in response to the reporting requirements contained in NRC Bulletin 88-09.             Inspections were performed at Beaver Valley Unit No. 1 during the sixth refueling outage which ended March 2, 1988, and therefore, this submittal specifically addresses Item 3.b of the Bulletin.         Inspections for Unit No. 2 are scheduled for tho first refueling outage which is expected to begin approximately March 17,       1989. Additionally, information regarding program development applicable to both Units is provided.
This submittal is in response to the reporting requirements contained in NRC Bulletin 88-09.
A formal       program for performing Flux Thimble Tube inspection has not been developed for Beaver Valley. The inspections on Unit No. 1 completed during the sixth refueling outage were performed using approved procedures with the intent of obtaining baseline information regarding thimble tube thinning. Several thimbles indicated wear and corrective action was taken following data analysis by our NSSS.                           One location (J-15) exceeded our acceptance criteria for rcmaining in service and four locations (B-5, D-12, J-5 and L-4) were repositioned to prevent further wear at the wear indications.             The acceptance criteria utilized was defined by our NSSS and will be discussed below.       This information was submitted to the NRC on June 29, 1988, on Licenseo Event Report 88-010-00.
Inspections were performed at Beaver Valley Unit No.
l
1 during the sixth refueling outage which ended March 2,
!            0911170109 801107                                                                         /.'fdh ADOCK 05000334 FDR 0                 FDC                                                                   JV
: 1988, and therefore, this submittal specifically addresses Item 3.b of the Bulletin.
                                                                                                            \\
Inspections for Unit No. 2 are scheduled for tho first refueling outage which is expected to begin approximately March 17, 1989.
Additionally, information regarding program development applicable to both Units is provided.
A formal program for performing Flux Thimble Tube inspection has not been developed for Beaver Valley.
The inspections on Unit No. 1 completed during the sixth refueling outage were performed using approved procedures with the intent of obtaining baseline information regarding thimble tube thinning.
Several thimbles indicated wear and corrective action was taken following data analysis by our NSSS.
One location (J-15) exceeded our acceptance criteria for rcmaining in service and four locations (B-5, D-12, J-5 and L-4) were repositioned to prevent further wear at the wear indications.
The acceptance criteria utilized was defined by our NSSS and will be discussed below.
This information was submitted to the NRC on June 29, 1988, on Licenseo Event Report 88-010-00.
l 0911170109 801107
/.'fdh FDR ADOCK 05000334 0
FDC JV
\\\\


    . Be0Vor VallCy Psw0r Statien, Unit Nac.1 & 2 Dockct No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09     Thimble Tube Thinning in Westinghouse Reactors Page 2 The   re-inspections   scheduled for Beaver Valley Unit No. I during the   seventh   refueling   outage, and the initial inspections scheduled for   Unit No. 2 during the first refueling outage will be performed in accordance     with an inspection program as described below. The inspection criteria and methodology discussed here were applicable to the initial inspection of the Unit No. I thimble tubes.                           Our program will be presented in a format consistent with the actions requested portion of NRC Bulletin 88-09.
Be0Vor VallCy Psw0r Statien, Unit Nac.1 & 2 Dockct No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09 Thimble Tube Thinning in Westinghouse Reactors Page 2 The re-inspections scheduled for Beaver Valley Unit No. I during the seventh refueling outage, and the initial inspections scheduled for Unit No. 2 during the first refueling outage will be performed in accordance with an inspection program as described below.
The inspection criteria and methodology discussed here were applicable to the initial inspection of the Unit No. I thimble tubes.
Our program will be presented in a format consistent with the actions requested portion of NRC Bulletin 88-09.
Actions _Requestedt l
Actions _Requestedt l
: 1. Each addressee is requested to establish an inspection program to monitor thimble tube performance.     This inspection program should includet
1.
                . the   establishment, with technical justification, of an appropriate thimble tube wear acceptance criterion (for
Each addressee is requested to establish an inspection program to monitor thimble tube performance.
,                    example,   percent   through-wall loss).     This acceptance
This inspection program should includet the establishment, with technical justification, of an appropriate thimble tube wear acceptance criterion (for
!                    criterion   should include allowances for such items as
: example, percent through-wall loss).
!                    inspection methodology and wear scar geometry uncertainties.
This acceptance criterion should include allowances for such items as inspection methodology and wear scar geometry uncertainties.
I An approved program will be in place prior     to conducting thimble tube inspections on Unit No. 2.       As previously stated, this outage is tentatively scheduled for mid-Narch,         1989. The Unit No. 1 seventh refueling outage is tentatively scheduled for September, 1989.
I An approved program will be in place prior to conducting thimble tube inspections on Unit No.
This   program will define appropriate thimble tube wear acceptance criterion   as follows.     Flux thimbles exhibiting wear indications in excess of 45% will be removed from service by closing the seal table isolation valve. During the Unit No. 1 initial examination, a finite element   structural analysis was performed that concluded a thimble
2.
!          tube could experience 60% material wear loss and still operation with an external pressure of 2250 psig.                                                             assure
As previously stated, this outage is tentatively scheduled for mid-Narch, 1989.
!                                                                  A 15%
The Unit No. 1 seventh refueling outage is tentatively scheduled for September, 1989.
used to account for inspection methodology and wear scar geometry           allowance                              is j         uncertainties.       This formed the basis for an acceptance criterion of 45%.
This program will define appropriate thimble tube wear acceptance criterion as follows.
I
Flux thimbles exhibiting wear indications in excess of 45% will be removed from service by closing the seal table isolation valve.
;              Tubes   exhibiting   indications   greater than or equal to 40% thru
During the Unit No. 1 initial examination, a finite element structural analysis was performed that concluded a thimble tube could experience 60%
'I         wall will   be axially repositioned to provide new wear surfaces. This criteria element was also applied to Unit No.1 and is supported by the finite analysis. This action provides assurance of pressure boundary integrity through the implementation of remedial corrective actions.
material wear loss and still assure operation with an external pressure of 2250 psig.
A 15% allowance is used to account for inspection methodology and wear scar geometry j
uncertainties.
This formed the basis for an acceptance criterion of 45%.
I Tubes exhibiting indications greater than or equal to 40% thru
'I wall will be axially repositioned to provide new wear surfaces.
This criteria was also applied to Unit No.1 and is supported by the finite element analysis.
This action provides assurance of pressure boundary integrity through the implementation of remedial corrective actions.


Beavor Vallcy Powcr Stction, Unit No3. 1&2 DockOt No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09: Thimble Tube Thinning in Westinghouse Reactors Page 3 Our   acceptance   criteria may   be   revised in the future based on further     refinement   of the accaptance   criteria following completion of a   Westinghouse     owners' Group (WOG) Program that is currently y'         underway.         This program will provide accurate eddy current wear scar                                         ,
Beavor Vallcy Powcr Stction, Unit No3. 1&2 DockOt No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09: Thimble Tube Thinning in Westinghouse Reactors Page 3 Our acceptance criteria may be revised in the future based on further refinement of the accaptance criteria following completion of a
standards via correlation with removed worn flux thimble samples from                                             '
Westinghouse owners' Group (WOG)
1 operating plants.
Program that is currently y'
the   establishment, with technical         justification, of an appropriate     inspection   frequency     (for   example, every refueling outage).
underway.
Our   program will define an inspection frequency of each refueling                                         i outage     based   on Beaver Valley Unit 1 experience to date. The WOG program will       provide wear rate estimates for various styles of Westinghouse plants.           The inspection frequency can then be adjusted                                       ,
This program will provide accurate eddy current wear scar standards via correlation with removed worn flux thimble samples from 1
to     reflect   the   results   of the WOG program and/or subsequent                                           i 1
operating plants.
examinations.
the establishment, with technical justification, of an appropriate inspection frequency (for
the establishment     of an inspection methodology that is                                           l capable of adequately detecting wear of the thimble tubes (such as addy current testing).
: example, every refueling outage).
l Since the postulated wear mechanism of flux thimbles is flow
Our program will define an inspection frequency of each refueling i
,          induced vibration, Beaver Valley has employed state of the art eddy                                               ,
outage based on Beaver Valley Unit 1 experience to date.
current testing for detection of degradation.                   This inspection                                   ,
The WOG program will provide wear rate estimates for various styles of Westinghouse plants.
technique       has proven to be capable of detecting flow induced                                                 '
The inspection frequency can then be adjusted to reflect the results of the WOG program and/or subsequent i
1          vibration       wear degradation in heat exchanger tubing.                                         Further         ;
1 examinations.
!        demonstration of the reliability of the eddy current technique will                                                 !
the establishment of an inspection methodology that is l
again be provided by the ongoing WoG program.                                                                       !
capable of adequately detecting wear of the thimble tubes (such as addy current testing).
The   above   represents the approach used for Unit No. 1 for the                                           !
l Since the postulated wear mechanism of flux thimbles is flow induced vibration, Beaver Valley has employed state of the art eddy current testing for detection of degradation.
initial     inspection of the thimble tubes and our intended program for                                           -
This inspection technique has proven to be capable of detecting flow induced 1
I          subsesuent inspections at both units. Program changes will occur as 1         more information becomes available either through the Woo or through                                               ,
vibration wear degradation in heat exchanger tubing.
the assessment of plant specific data.                                                                             '
Further demonstration of the reliability of the eddy current technique will again be provided by the ongoing WoG program.
l If you have any questions           regarding     this   submittal,                           please         ,
The above represents the approach used for Unit No. 1 for the initial inspection of the thimble tubes and our intended program for I
contact me or members of my staff.
subsesuent inspections at both units.
,                                                    very Truly yours,                                                       '
Program changes will occur as 1
k        k q                                                   / J. D. Sieber                                                             ,
more information becomes available either through the Woo or through the assessment of plant specific data.
l Vice Fresident, Nuclear                                                 ;
l If you have any questions regarding this submittal, please contact me or members of my staff.
i i
very Truly yours, k
cc:     Mr. J. Beall, Sr. Resident Inspector Mr. W. T. Russell, NRC Region I Administrator                                                             t Mr. P. Tam, Project Manager                                                                               :
k q
;                  Director, Safety Evaluation & Control (VEPCO)
/ J.
D. Sieber l Vice Fresident, Nuclear i
i cc:
Mr. J.
Beall, Sr. Resident Inspector Mr.
W. T.
Russell, NRC Region I Administrator t
Mr.
P. Tam, Project Manager Director, Safety Evaluation & Control (VEPCO)


    . . S.
.. S.
COMMONWEALTH OF PENNSYLVANIA)
COMMONWEALTH OF PENNSYLVANIA)
                                                              ) SS:
)
COUNTY OF BEAVER                     )
SS:
l 1
COUNTY OF BEAVER
l l
)
I I
On this 7-day of.
On   this               7-           day of .         644 e                           CA1/                                                     , 1988, before    me,      es      _d [ [,m . M / ',   a     Hotary Public in and for said commonwealth     and   County, personally appeated J. D. Sieber, who being duly   sworn,   deposed,       and said that (1) he is Vice President of Duquesne Light,       ( 'J )   he is duly authorired to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set   forth   in   the       Submittal are true and correct to the best of his knowledge, information and belief.
644 e CA1/
g)                   ''
, 1988,
                                                                                                                                                ,e
_d [ [,m. M / ',
($                 f                       Off                                               -0 15:           s ~0 r. .      ,                          , t i .i M f.i f L 6. 'i n 1,N LX: 1.:: d t iC i Of.,E R ,'Q 1 ;O m}}
a Hotary Public in and for said before me, es commonwealth and County, personally appeated J. D. Sieber, who being duly
: sworn, deposed, and said that (1) he is Vice President of Duquesne
: Light,
( 'J )
he is duly authorired to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.
g)
,e
($
f Off
-0 15:
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, t i.i M f.i f L 6. 'i n 1,N LX: 1.:: d t iC i Of.,E R,'Q 1 ;O m}}

Latest revision as of 02:05, 7 December 2024

Responds to NRC Bulletin 88-009, Thimble Tube Thinning in Westinghouse Reactors. Formal Program for Performing Flux Thimble Tube Insp Not Developed for Plant.Util Program Will Be Presented in Format Consistent W/Guidelines in Bulletin
ML20206D504
Person / Time
Site: Beaver Valley
Issue date: 11/07/1988
From: Sieber J
DUQUESNE LIGHT CO.
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
IEB-88-009, IEB-88-9, NUDOCS 8811170109
Download: ML20206D504 (4)
v • d • e


Text

_ _ _ _ _ _ _ _ -.

C OLn g @ CCgilpagly B;lg,gev %c w=

sewt mwnm P e N ew Gw4

=4? unm November 7, 1988 U.

S.

Nuclear Regulatory Commission Attn:

Document Control Desk Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, License No. DPR-66 BV-2 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09 Thimble Tube Thinning in Westinghouso Reactors Gentlemen:

This submittal is in response to the reporting requirements contained in NRC Bulletin 88-09.

Inspections were performed at Beaver Valley Unit No.

1 during the sixth refueling outage which ended March 2,

1988, and therefore, this submittal specifically addresses Item 3.b of the Bulletin.

Inspections for Unit No. 2 are scheduled for tho first refueling outage which is expected to begin approximately March 17, 1989.

Additionally, information regarding program development applicable to both Units is provided.

A formal program for performing Flux Thimble Tube inspection has not been developed for Beaver Valley.

The inspections on Unit No. 1 completed during the sixth refueling outage were performed using approved procedures with the intent of obtaining baseline information regarding thimble tube thinning.

Several thimbles indicated wear and corrective action was taken following data analysis by our NSSS.

One location (J-15) exceeded our acceptance criteria for rcmaining in service and four locations (B-5, D-12, J-5 and L-4) were repositioned to prevent further wear at the wear indications.

The acceptance criteria utilized was defined by our NSSS and will be discussed below.

This information was submitted to the NRC on June 29, 1988, on Licenseo Event Report 88-010-00.

l 0911170109 801107

/.'fdh FDR ADOCK 05000334 0

FDC JV

\\\\

Be0Vor VallCy Psw0r Statien, Unit Nac.1 & 2 Dockct No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09 Thimble Tube Thinning in Westinghouse Reactors Page 2 The re-inspections scheduled for Beaver Valley Unit No. I during the seventh refueling outage, and the initial inspections scheduled for Unit No. 2 during the first refueling outage will be performed in accordance with an inspection program as described below.

The inspection criteria and methodology discussed here were applicable to the initial inspection of the Unit No. I thimble tubes.

Our program will be presented in a format consistent with the actions requested portion of NRC Bulletin 88-09.

Actions _Requestedt l

1.

Each addressee is requested to establish an inspection program to monitor thimble tube performance.

This inspection program should includet the establishment, with technical justification, of an appropriate thimble tube wear acceptance criterion (for

example, percent through-wall loss).

This acceptance criterion should include allowances for such items as inspection methodology and wear scar geometry uncertainties.

I An approved program will be in place prior to conducting thimble tube inspections on Unit No.

2.

As previously stated, this outage is tentatively scheduled for mid-Narch, 1989.

The Unit No. 1 seventh refueling outage is tentatively scheduled for September, 1989.

This program will define appropriate thimble tube wear acceptance criterion as follows.

Flux thimbles exhibiting wear indications in excess of 45% will be removed from service by closing the seal table isolation valve.

During the Unit No. 1 initial examination, a finite element structural analysis was performed that concluded a thimble tube could experience 60%

material wear loss and still assure operation with an external pressure of 2250 psig.

A 15% allowance is used to account for inspection methodology and wear scar geometry j

uncertainties.

This formed the basis for an acceptance criterion of 45%.

I Tubes exhibiting indications greater than or equal to 40% thru

'I wall will be axially repositioned to provide new wear surfaces.

This criteria was also applied to Unit No.1 and is supported by the finite element analysis.

This action provides assurance of pressure boundary integrity through the implementation of remedial corrective actions.

Beavor Vallcy Powcr Stction, Unit No3. 1&2 DockOt No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 NRC Bulletin 88-09: Thimble Tube Thinning in Westinghouse Reactors Page 3 Our acceptance criteria may be revised in the future based on further refinement of the accaptance criteria following completion of a

Westinghouse owners' Group (WOG)

Program that is currently y'

underway.

This program will provide accurate eddy current wear scar standards via correlation with removed worn flux thimble samples from 1

operating plants.

the establishment, with technical justification, of an appropriate inspection frequency (for

example, every refueling outage).

Our program will define an inspection frequency of each refueling i

outage based on Beaver Valley Unit 1 experience to date.

The WOG program will provide wear rate estimates for various styles of Westinghouse plants.

The inspection frequency can then be adjusted to reflect the results of the WOG program and/or subsequent i

1 examinations.

the establishment of an inspection methodology that is l

capable of adequately detecting wear of the thimble tubes (such as addy current testing).

l Since the postulated wear mechanism of flux thimbles is flow induced vibration, Beaver Valley has employed state of the art eddy current testing for detection of degradation.

This inspection technique has proven to be capable of detecting flow induced 1

vibration wear degradation in heat exchanger tubing.

Further demonstration of the reliability of the eddy current technique will again be provided by the ongoing WoG program.

The above represents the approach used for Unit No. 1 for the initial inspection of the thimble tubes and our intended program for I

subsesuent inspections at both units.

Program changes will occur as 1

more information becomes available either through the Woo or through the assessment of plant specific data.

l If you have any questions regarding this submittal, please contact me or members of my staff.

very Truly yours, k

k q

/ J.

D. Sieber l Vice Fresident, Nuclear i

i cc:

Mr. J.

Beall, Sr. Resident Inspector Mr.

W. T.

Russell, NRC Region I Administrator t

Mr.

P. Tam, Project Manager Director, Safety Evaluation & Control (VEPCO)

.. S.

COMMONWEALTH OF PENNSYLVANIA)

)

SS:

COUNTY OF BEAVER

)

On this 7-day of.

644 e CA1/

, 1988,

_d [ [,m. M / ',

a Hotary Public in and for said before me, es commonwealth and County, personally appeated J. D. Sieber, who being duly

sworn, deposed, and said that (1) he is Vice President of Duquesne
Light,

( 'J )

he is duly authorired to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.

g)

,e

($

f Off

-0 15:

s ~0 r.

, t i.i M f.i f L 6. 'i n 1,N LX: 1.:: d t iC i Of.,E R,'Q 1 ;O m

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