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=Text=
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8vP         APV b VWPI bl3! OA hNpp*FO"1 PA 1W 7 0004 M*4 D Srf 3tB w . row     %., c,m.                                                                                 mm" June 14, 1991 U. S. Nuclear Regulatory Commission Attn:                           Document Control Desk Wushington, DC 20555
8vP APV b VWPI bl3! OA hNpp*FO"1 PA 1W 7 0004 M*4 D Srf 3tB w. row
%., c,m.
mm" June 14, 1991 U.
S.
Nuclear Regulatory Commission Attn:
Document Control Desk Wushington, DC 20555


==Subject:==
==Subject:==
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769)
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769)
Ref: Letter     from               A.W.           DeAgazio     (Nuclear         Regulatory Commission)       to               J.D. Sieber (Duquesne Light Company),
Ref: Letter from A.W.
DeAgazio (Nuclear Regulatory Commission) to J.D.
Sieber (Duquesne Light Company),


==Subject:==
==Subject:==
Main Feedwater Piping Elbow                                 Cracking and Misalignment (TAC 79769), April 17, 1991.
Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769), April 17, 1991.
This letter provides a response to the main feedwater system piping verificatio.' requested in the referenced letter.                                                               Each requested verification is presented followed by the actions taken to determine acceptability.
This letter provides a
REQUESTED VERIFICATION Verification that the affected                                 feedwater   piping satisfies the licensing basis for plant piping.
response to the main feedwater system piping verificatio.'
ACTIONS A.         Design change 1684 replaced monoballs on the A and C main feedwater lines with passive (rigid box) supports during the eighth refueling outage.
requested in the referenced letter.
B.       The operating manual procedures have been revised so that the main feedwater bypass regulating valves are normally closed above 30 percent power.
Each requested verification is presented followed by the actions taken to determine acceptability.
C.       With   the above changes in design and operation, applicable p1pe   rupture criteria in Regulatory Guide 1.46 can be satisfied at all power levels.                             Applicable pipe rupture criteria will be incorporated into the UFSAR as shown in the Attaohment.
REQUESTED VERIFICATION Verification that the affected feedwater piping satisfies the licensing basis for plant piping.
                                                                                                                                                                                                                ,0 0 9106260316 910614                                                                                                         \\
ACTIONS A.
PDR                   ADOE 05000334 p                                     f'DR
Design change 1684 replaced monoballs on the A and C main feedwater lines with passive (rigid box) supports during the eighth refueling outage.
B.
The operating manual procedures have been revised so that the main feedwater bypass regulating valves are normally closed above 30 percent power.
C.
With the above changes in design and operation, applicable p1pe rupture criteria in Regulatory Guide 1.46 can be satisfied at all power levels.
Applicable pipe rupture criteria will be incorporated into the UFSAR as shown in the Attaohment.
0
,0 9106260316 910614
\\\\
PDR ADOE 05000334 p
f'DR


1
1
                                                                                                                  .l LBeaver Valley ~ Power Station,-Unit No. 1 Docket'No. 50-334, License No. DPR-66 Main Feedwater piping Elbow Cracking and Misalignment (TAC 79769)
.l LBeaver Valley ~ Power Station,-Unit No. 1 Docket'No. 50-334, License No. DPR-66
. Main Feedwater piping Elbow Cracking and Misalignment (TAC 79769)
Page 2 REQUESTED VERIFICATION
Page 2 REQUESTED VERIFICATION
                          - Verification               that the feedwater lines are free of binding or
- Verification that the feedwater lines are free of binding or
                          ' interference               with- pipe-rupture restraints under all thermal conditions.
' interference with-pipe-rupture restraints under all thermal conditions.
ACTIONS A.               Main _feedwater -piping was walked down at the completion of design change 1684 and replacement-of an elbow on the "C" loop.-   It has been verified that the lines are free of binding or interference with the pipe rupture restraints.            .
ACTIONS A.
B.               Analytical evaluations of main feedwater pipe movement were reviewed to verify that spacing at pipe supports and rupture         '
Main _feedwater -piping was walked down at the completion of design change 1684 and replacement-of an elbow on the "C" loop.-
                                            -restraints are adequate under all thermal conditions.         This review entailed a comparison of existing gaps at restraints versus     calculated     dittolacements   under   all   thermal conditions.       Under -stratified conditions, the piping will close gaps _at specific restraints. This was incorporated in the. analyses and it has been determined that piping will remain within the design basis stress criteria under all thermal conditions.
It has been verified that the lines are free of binding or interference with the pipe rupture restraints.
C.               Temperature     and   displacement     instrumentation has been installed at -certain locations on nain feedwater piping loops A and C to_ gather more information and furtaer define.
B.
Global Thermal Stratification effects.             Each temperature monitoring location has a minimum of three (3) thermocouples located at- the top,       bottom and on the side of-the pipe.
Analytical evaluations of main feedwater pipe movement were reviewed to verify that spacing at pipe supports and rupture
-restraints are adequate under all thermal conditions.
This review entailed a comparison of existing gaps at restraints versus calculated dittolacements under all thermal conditions.
Under -stratified conditions, the piping will close gaps _at specific restraints.
This was incorporated in the. analyses and it has been determined that piping will remain within the design basis stress criteria under all thermal conditions.
C.
Temperature and displacement instrumentation has been installed at -certain locations on nain feedwater piping loops A
and C to_ gather more information and furtaer define.
Global Thermal Stratification effects.
Each temperature monitoring location has a minimum of three (3) thermocouples located at-the
: top, bottom and on the side of-the pipe.
Each' ' displacement location has three-(3) lanyards to measure.
Each' ' displacement location has three-(3) lanyards to measure.
the-veritcal, lateral and axial deflections of the pipe.
the-veritcal, lateral and axial deflections of the pipe.
Based             upon   the . actions summarized above, we have concluded that 1                -the ; main _feedwater                 piping has_ been restored to- a satisfactory 0,         - configuration for plant operation.                               Should you have any questions regarding this response, please contact Mr. Ken McMullen at_(412) 393-5214.
Based upon the. actions summarized above, we have concluded that
i L                                                                                   Sincerely,
-the ; main _feedwater piping has_ been restored to-a satisfactory 10,
                                                                                  /. D. Sieber Vice President Nuclear Group-L                   Attachment i
- configuration for plant operation.
cc:       Mr.           J. Beall, Sr. Resident' Inspector Mr.           T. T. Martin, NRC Region I Administrator Mr.           A. W. DeAgazio,-Project Manager Mr.           R. Saunders'(VEPCO) 1T4W             'g- t - + , + - -                           w
Should you have any questions regarding this
: response, please contact Mr. Ken McMullen at_(412) 393-5214.
i L
Sincerely,
/.
D.
Sieber Vice President Nuclear Group-L Attachment i
cc:
Mr.
J.
Beall, Sr. Resident' Inspector Mr.
T.
T. Martin, NRC Region I Administrator Mr.
A.
W.
DeAgazio,-Project Manager Mr.
R. Saunders'(VEPCO) 1T4W W
'g-t
- +, + - -
t-N-b ig-w


KI"I'ACHMENI Beaver Valley Power Station, Unit No. 1 Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769)
KI"I'ACHMENI Beaver Valley Power Station, Unit No. 1 Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769)
Updated Final Safety Analysis Report Changes to Incorporate Regulatory Guide-1.46 Pipe Rupture Critoria h L. W A E:.4 %- &.  ,
Updated Final Safety Analysis Report Changes to Incorporate Regulatory Guide-1.46 Pipe Rupture Critoria h
L. W A E:.4


BVPS-1-UPDATED FSAR           Rev. 1 (1/83)
BVPS-1-UPDATED FSAR Rev. 1 (1/83)
The missile with the highest kinetic energy-to-impact area ratio ( KE/A ), which is considered the most dertructive missile, is a propane bottle relief device
The missile with the highest kinetic energy-to-impact area ratio
(".ype 3) with KE/A of 7656 ft-lb per square i-h. The F E/ A of 9195 ft-lb per square inch for the design lasis missile compared to the maximum KE/A from Table 5.2-15 justifies the " exclusion from further analysis" approach of the safety related equipment isolated by missile proof walls.
( KE/A ),
5.2.6.2   Exterior Missiles The containment has     not been analyzed       for exterior missiles generated by hypothetical aircraft accidents, due to the site being located more than 5 miles from any airport (Table 2.1-7 ) .
which is considered the most dertructive missile, is a propane bottle relief device
(".ype 3) with KE/A of 7656 ft-lb per square i-h.
The F E/ A of 9195 ft-lb per square inch for the design lasis missile compared to the maximum KE/A from Table 5.2-15 justifies the
" exclusion from further analysis" approach of the safety related equipment isolated by missile proof walls.
5.2.6.2 Exterior Missiles The containment has not been analyzed for exterior missiles generated by hypothetical aircraft accidents, due to the site being located more than 5 miles from any airport (Table 2.1-7 ).
Tornado generated missiles discussed in Section 2.7 include one potential missile equivalent to a 35-ft long wooden utility pole impacting at a velocity of 150 mph.
Tornado generated missiles discussed in Section 2.7 include one potential missile equivalent to a 35-ft long wooden utility pole impacting at a velocity of 150 mph.
5.2.6.3   Criteria for Protection Against Dynamic Effects Associated with a Major Pipe Rupture The containment vessel and all essential equipment within the containment are adequately protected against the effects of blowdown jet forces and pipe whip resulting from a postulated pipe   rupture of reactor     coolant (Class 1) , main steam,                       and feedwater (Class 2) lines. The criteria for adequate protection permits limited damage when analysis or experiment demonstrates that:
5.2.6.3 Criteria for Protection Against Dynamic Effects Associated with a Major Pipe Rupture The containment vessel and all essential equipment within the containment are adequately protected against the effects of blowdown jet forces and pipe whip resulting from a postulated pipe rupture of reactor coolant (Class
: 1. Leakage through the containment will not cause offsite dose   consequences   in     excess of   10CFR                   part 100 guidelines.
: 1),
: 2. The minimum performance capabilities of the engineered safety systems are not reduced below that required to protect against the postulated break.
main
: 3. A pipe break which is not a loss of reactor coolant will not cause a loss of reactor coolant or steam or feedwater line break.     Also, a reactor coolant system pipe break will not cause a steam-feedwatar system pipe break and vice versa.
: steam, and feedwater (Class 2) lines.
The criteria for adequate protection permits limited damage when analysis or experiment demonstrates that:
1.
Leakage through the containment will not cause offsite dose consequences in excess of 10CFR part 100 guidelines.
2.
The minimum performance capabilities of the engineered safety systems are not reduced below that required to protect against the postulated break.
3.
A pipe break which is not a loss of reactor coolant will not cause a loss of reactor coolant or steam or feedwater line break.
Also, a reactor coolant system pipe break will not cause a steam-feedwatar system pipe break and vice versa.
This level of protection is assured by adherence to the following design criteria.
This level of protection is assured by adherence to the following design criteria.
Placement of Piping and Comoonents The routing of pipe and the placement of components minimize the possibility of damage.               ,
Placement of Piping and Comoonents The routing of pipe and the placement of components minimize the possibility of damage.
PROVIDED FOR INFORMATION ONLY 5.2-58           (NO CHANGES TO THIS PAGE)
PROVIDED FOR INFORMATION ONLY 5.2-58 (NO CHANGES TO THIS PAGE)


BVPS-1-UPDATED FSAR                             Rev. 1 (1/83) f l
f BVPS-1-UPDATED FSAR Rev. 1 (1/83) l The polar crane wall serves as a barrier between the reactor coolant loops and the containment liner.
The polar crane wall serves as a barrier                           between In addition, the reactor the coolant loops and the containment liner.
In
refueling cavity walls, various structural beams, the operating floor, and the crane wall, enclose each reactor coolant loop into a separate compartment, thereby preventing an accident, which may occur in any loop, from affecting another loop or the containment liner.       The portion of the steam and feedwater lines within the containment have been routed behind barriers                         which separate these lines f rom all reactor coolant piping. The barriers described above will withstand loadings caused by jet forces and pipe whip impact forces.
: addition, the cavity walls, various structural beams, the operating refueling floor, and the crane wall, enclose each reactor coolant loop into a separate compartment, thereby preventing an accident, which may occur in any loop, from affecting another loop or the containment liner.
Other than for the Emergency Core Cooling System lines, which must circulate cooling water to the vessel, the engineered                                                     safety The Emergency features are located outside of the crane wall.
The portion of the steam and feedwater lines within the containment have been routed behind barriers which separate these lines f rom all reactor coolant piping.
Core Cooling System lines are routed outside of the crane wall so that the penetrations are in the vicinity of the loop to which they are attached.
The barriers described above will withstand loadings caused by jet forces and pipe whip impact forces.
Supplemental Protection careful             layout                       of     piping     and In    those regions      where    the components cannot       offer adequate protection against the dynamic effects associated with a postulated pipe rupture, restraints to prevent excessive pipe movement or special shielding is provided.
Other than for the Emergency Core Cooling System lines, which must circulate cooling water to the vessel, the engineered safety features are located outside of the crane wall.
The careful layout of piping and components offers adequate dynamic     effects           associated                             with     a protection      against      the in the case of the main steam and postulated pipe rupture exceptcrane wall and the pressurizer surge feedwater lines outside the line.
The Emergency Core Cooling System lines are routed outside of the crane wall so that the penetrations are in the vicinity of the loop to which they are attached.
Supplemental Protection In those regions where the careful layout of piping and cannot offer adequate protection against the dynamic components restraints to effects associated with a postulated pipe rupture, prevent excessive pipe movement or special shielding is provided.
The careful layout of piping and components offers adequate protection against the dynamic effects associated with a
in the case of the main steam and postulated pipe rupture exceptcrane wall and the pressurizer surge feedwater lines outside the line.
In the case of the pressurizer surge line, a sufficient number of restraints are provided such that, following a single break, the unrestrained pipe movement of either end of the ruptured pipe about a plastic hinge formed at the nearest pipe whip restraint cannot impact any structcre, system or component important to safety.
In the case of the pressurizer surge line, a sufficient number of restraints are provided such that, following a single break, the unrestrained pipe movement of either end of the ruptured pipe about a plastic hinge formed at the nearest pipe whip restraint cannot impact any structcre, system or component important to safety.
The basis for selecting break locations in the main steam and feedwater systems, whose piping is similar to ASME Boiler and Pressure Vessel Code, Section III, Class 2 piping, is discussed belowv         and is consistent with Regulatory Guide 1.46
The basis for selecting break locations in the main steam and feedwater systems, whose piping is similar to ASME Boiler and Pressure Vessel Code, Section III, Class 2 piping, is discussed belowv and is consistent with Regulatory Guide 1.46
                      " Protection Against Pipe Whip Inside Containment."
" Protection Against Pipe Whip Inside Containment."
      .Since the probability of rupture is strongly related to stress, only     a limited number         of   break             locations                         are postulated.
.Since the probability of rupture is strongly related to stress, only a
is   provided             on   the                         main     steam     and Supplemental protection feedwater lines for breaks at e-1 locationsAwh:::                                               the       trern cacced: 90 p : cent of th: :llewable strest.                                                 =ini=u=     cf three bre:h lec: tion: ver       p::tul:ted by the fellering criteria:
limited number of break locations are postulated.
At the two terminal points                                                            d9 scribed below:
Supplemental protection is provided on the main steam and feedwater lines for breaks at e-1 locations wh::: the trern cacced: 90 p : cent of th: :llewable strest.
A =ini=u= cf three bre:h lec: tion: ver p::tul:ted by the fellering criteria:
d9 scribed below:
1.
1.
: 2. At the point of maximum primary plus secondary stress 5.2-59
At the two terminal points 2.
At the point of maximum primary plus secondary stress 5.2-59


BVPS-1-UPDATED PSAR                 Rev. 1 (1/83) h
BVPS-1-UPDATED PSAR Rev. 1 (1/83) h 3.
: 3. At any other point where the primaryallowable;    plus secondary                                   i.e.,
At any other point where the primary plus secondary stress exc >ds 80 percent of its allowable; i.e.,
stress exc >ds 80 percent of its cccendary    ctrccc                                  cxcccds-0.8 (S +S       . Or     the 00 pcr cat o)f it:         211c'c?2b le ; i.e., 0.8 C           ,                          Or     the primary ctrecc execcdc 90 perecnt of it: _ l let?2b ic ;
0.8 (S
three i O''
+S Or the cccendary ctrccc cxcccds-00 pcr cat
There are 09 U 2 Q*                   Each The main steam and feedwater piping (similar to ASME Boiler and Pressure Vessel Code III, Class 2 piping) requires pipe break restraints in order to protect the integrity of the containment Of the six piping runs -hve- runc cach contain a total of s
)f o
lines.
it:
or more postulated break points. Thc brcch locatienc 2re picked "Scre there ic 2 charp change ir ctrecc icvel                           c2cng
211c'c?2b le ;
                                                                                .cthed                            to-- pthe ich 1-eng th cf pipe.     There cec   =0 te 50 ne reasenchle one --- pc int vercuc ancther         Sen the ctrccc icvci docc not ecry apprecichly cleng the pipe run.
i.e.,
Table 5.2-16 gives the pipe break locations postulated for the three main steam and three main feedwater pipe runs inside the containment building.         The loop A main steam line contains three and/or     areas.     Figures 5.2-33       through                                     5.2-38 break    points coordinate the point numbers, given in Table 5.2-16 to a location along the pipe run. The restraint locations for main steam lines and for main feedwater lines are provided in Figures 5.2-39 and 5.2-40 respectively.         Restraint locations are based upon what were, at the time of design fixing, the prevailing criteria for number and type of break.
0.8 C Or the primary ctrecc execcdc 90 perecnt of it: _ l let?2b ic ;
offer   good     supplemental       protection             since                                 pipe Restraints displacements are         minimized       and   large   kinetic energies are prevented.
i O'' 09 U 2 Q*
The placement of the             restraints will prevent excessive pipe displacements in the event of either a longitudinal split or circumferential break, or both, depending on the state of stress in the line.
Each three There are The main steam and feedwater piping (similar to ASME Boiler and Pressure Vessel Code III, Class 2 piping) requires pipe break restraints in order to protect the integrity of the containment lines.
In   the   area where     the     feedwater and the main steam piping penetrate    the containment shell, the liner is also protected by an overlay of 1 1/2 inch thick quenched and tempered steel plate.
Of the six piping runs -hve-runc cach contain a total of s
or more postulated break points.
Thc brcch locatienc 2re picked "Scre there ic 2 charp change ir ctrecc icvel c2cng the 1-eng th cf pipe.
There cec =0 te 50 ne reasenchle
.cthed to-- p i c h one --- pc int vercuc ancther Sen the ctrccc icvci docc not ecry apprecichly cleng the pipe run.
Table 5.2-16 gives the pipe break locations postulated for the three main steam and three main feedwater pipe runs inside the containment building.
The loop A main steam line contains three break points and/or areas.
Figures 5.2-33 through 5.2-38 coordinate the point numbers, given in Table 5.2-16 to a location along the pipe run.
The restraint locations for main steam lines and for main feedwater lines are provided in Figures 5.2-39 and 5.2-40 respectively.
Restraint locations are based upon what were, at the time of design fixing, the prevailing criteria for number and type of break.
Restraints offer good supplemental protection since pipe displacements are minimized and large kinetic energies are prevented.
The placement of the restraints will prevent excessive pipe displacements in the event of either a longitudinal split or circumferential break, or both, depending on the state of stress in the line.
In the area where the feedwater and the main steam piping the containment shell, the liner is also protected by penetrate an overlay of 1 1/2 inch thick quenched and tempered steel plate.
Methods of Analysir.
Methods of Analysir.
In Analyses are performed for pipe impact and jet impingement.                                 to                  ensure addition,     major   equipment       supports are analyzed adequacy under       postulated pipe         rupture loads transmitted by attached piping.
Analyses are performed for pipe impact and jet impingement.
In
: addition, major equipment supports are analyzed to ensure adequacy under postulated pipe rupture loads transmitted by attached piping.
For the purposes of design, unless otherwise stated, the pipe break event is considered a faulted condition, and the pipe, its restraint or barrier, and the structure to which it is attached are designed accordingly.
For the purposes of design, unless otherwise stated, the pipe break event is considered a faulted condition, and the pipe, its restraint or barrier, and the structure to which it is attached are designed accordingly.
l 5.2-60
l 5.2-60


BVPS-1-UPDATED FSAR                                                     Rev. 1 (1/83)
BVPS-1-UPDATED FSAR Rev. 1 (1/83)
Restraints which require plastic                           deformation                                               are   based   on 50 parcent of ultimate strain.
Restraints which require plastic deformation are based on 50 parcent of ultimate strain.
The forces associated with both longitudinal and circumferential ruptures are considered in the design of supports and restraints in order to ensure continued integrity of vital components and engineered sa fety features.
The forces associated with both longitudinal and circumferential ruptures are considered in the design of supports and restraints in order to ensure continued integrity of vital components and engineered sa fety features.
The break area                       for   both postulated break                                                   types   is   the cross-sectional area of                       the pipe. The   break                                             length   for the
The break area for both postulated break types is the cross-sectional area of the pipe.
            ,ostulated longitudinal breaks is assumed to be equal to twice the pipe diameter.
The break length for the
The analysis takes advantage of limiting factors on the blowdown thrust force, such as line friction, flow restrictors,                                                                           pipe configuration, etc.                     A rise time is applied   to                               the             thrust force to simulate the crack opening time.                       A one millisecond rise time is assumed for circumferential breaks.                         For longitudinal splits, a rise time is computed based on the growth of a crack from a critical length to a length of                             two   pipe                                       diameters         at   a propagation rate of 500 ft/second.
,ostulated longitudinal breaks is assumed to be equal to twice the pipe diameter.
Pipe Restraints The restraints are designed with a gap sufficient to prevent interference with the normal thermal dynamic motion of the lines.                                                                      .
The analysis takes advantage of limiting factors on the blowdown thrust
This permits the pipe to acquire kinetic energy which must be dissipated upon impact into the                         restraint.                                               This energy was conservatively set equal to the product of peak thrust times displacement.                   No energy disstpation mechanisms operating prior to   impact, such as plastic deformation in the pipe, were considered. Static analyses of the deformation of the restraints and bolts provided the force displacements characteristics of the restraints.         The area (energy) under this force-displacement curve was matched to the. kinetic energy of the impacting pipe to determine the deformation and load.                           Based on recent, more detailed analyses, the conservatism of this design approach has been proven.
: force, such as line
Figures 5.2-39                   and 5.2-40 show the configurations of typical piping restraints and locations of such restraints for the main steam system and feedwater system, respectively.                                                                   Figures 5.2-41 and 5.2-42-show the similar information for the pressurizer surge line.
: friction, flow restrictors, pipe configuration, etc.
A rise time is applied to the thrust force to simulate the crack opening time.
A one millisecond rise time is assumed for circumferential breaks.
For longitudinal splits, a rise time is computed based on the growth of a crack from a critical length to a
length of two pipe diameters at a
propagation rate of 500 ft/second.
Pipe Restraints The restraints are designed with a gap sufficient to prevent interference with the normal thermal dynamic motion of the lines.
This permits the pipe to acquire kinetic energy which must be dissipated upon impact into the restraint.
This energy was conservatively set equal to the product of peak thrust times displacement.
No energy disstpation mechanisms operating prior to
: impact, such as plastic deformation in the
: pipe, were considered.
Static analyses of the deformation of the restraints and bolts provided the force displacements characteristics of the restraints.
The area (energy) under this force-displacement curve was matched to the. kinetic energy of the impacting pipe to determine the deformation and load.
Based on
: recent, more detailed analyses, the conservatism of this design approach has been proven.
Figures 5.2-39 and 5.2-40 show the configurations of typical piping restraints and locations of such restraints for the main steam system and feedwater system, respectively.
Figures 5.2-41 and 5.2-42-show the similar information for the pressurizer surge line.
The restraints consist of a circular arch (or yoke) and a welded base support structure that is bolted to a supporting wall.
The restraints consist of a circular arch (or yoke) and a welded base support structure that is bolted to a supporting wall.
These restraints are designed so that, by the use of self-adjusting shims, the gap between the pipe and the inner surface of the restraint is kept as small as practicable while still allowing free                     thermal   expansion   of   the                     pipe                           during   plant operation.
These restraints are designed so
5.2-61     PROVIDED FOR INFORMATION ONLY (NO CHANGES TO THIS PAGE)
: that, by the use of self-adjusting shims, the gap between the pipe and the inner surface of the restraint is kept as small as practicable while still allowing free thermal expansion of the pipe during plant operation.
PROVIDED FOR INFORMATION ONLY 5.2-61 (NO CHANGES TO THIS PAGE)


BVPS-1-UPDATED FSAR           Rev. 1 (1/83)
BVPS-1-UPDATED FSAR Rev. 1 (1/83)
The barrier provided near the containment penetration is attached to the pipe penetration sleeve.
The barrier provided near the containment penetration is attached to the pipe penetration sleeve.
Equipment Supports The internal structural system of the containment is designed to mitigate loading due to rupture in the main reactor coolant lines and the main steam and feedwater lines.           Incident rupture is considered in only one line at a time. The support system is designed to preclude damage to or rupture of any of the other lines as a result of the incident. The snubber and key systems are designed to deliver rupture thrusts on the steam generator into the internal structural system.       In determining the steam-generator   support reactions, the system is reduced       to a dynamic model consisting of a suitable number of masses and resistance elements. The dynamic problem is solved by numerical methods, using a thrust time history as       loading. Resistance,   dynamic amplification of the thrust, and rebound forces are calculated as a function of time.     The reactor vessel and support system is similarly treated.
Equipment Supports The internal structural system of the containment is designed to mitigate loading due to rupture in the main reactor coolant lines and the main steam and feedwater lines.
l     5.2.6.4   Pipe Whip Analysis The analysis of the restrained piping within the containment was completed and the fabrication of restraints begun before any officially   acceptable   criteria   for   analysis   was   published.
Incident rupture is considered in only one line at a time.
Subsequent to the completion of the analysis, analytical methods and criteria to be used in determining pipe whip analysis was transmitted to DLC from the AEC.         The analytical methods and criteria are provided in Attachment A to Section 5.2, " Pipe Whip Analysis Guidelines". The analytical methods and criteria used were similar to, but not identical with, those outlined in Attachment A. To facilitate a comparison, the original criteria is provided in Attachment B using the format of Attachment A and a point-by-point comparison is presented.     Emphasis is placed on those criteria which differ.
The support system is designed to preclude damage to or rupture of any of the other lines as a result of the incident.
5.2.7   Corrosion Protection and Coatj gg, 5.2.7.1   Steel Liner The exterior of the steel liner is not coated because it is in intimate contact with the concrete and has adequate protection from corrosion. The interior of the stsal liner has an inorganic zine coating with a white epoxy topcoating which provides protection for both normal operating and accident conditions.
The snubber and key systems are designed to deliver rupture thrusts on the steam generator into the internal structural system.
5.2.7.2 Concrete and Structural Steel All   interior concrete   and structural steel surfaces in the containment structure were given a coating suitable for service under DBA conditions. The steel floor grating is galvanized.
In determining the steam-generator support reactions, the system is reduced to a dynamic model consisting of a suitable number of masses and resistance elements.
The dynamic problem is solved by numerical methods, using a thrust time history as loading.
Resistance, dynamic amplification of the thrust, and rebound forces are calculated as a function of time.
The reactor vessel and support system is similarly treated.
l 5.2.6.4 Pipe Whip Analysis The analysis of the restrained piping within the containment was completed and the fabrication of restraints begun before any officially acceptable criteria for analysis was published.
Subsequent to the completion of the analysis, analytical methods and criteria to be used in determining pipe whip analysis was transmitted to DLC from the AEC.
The analytical methods and criteria are provided in Attachment A to Section 5.2, " Pipe Whip Analysis Guidelines".
The analytical methods and criteria used were similar to, but not identical with, those outlined in Attachment A.
To facilitate a comparison, the original criteria is provided in Attachment B using the format of Attachment A and a point-by-point comparison is presented.
Emphasis is placed on those criteria which differ.
5.2.7 Corrosion Protection and Coatj gg, 5.2.7.1 Steel Liner The exterior of the steel liner is not coated because it is in intimate contact with the concrete and has adequate protection from corrosion.
The interior of the stsal liner has an inorganic zine coating with a
white epoxy topcoating which provides protection for both normal operating and accident conditions.
5.2.7.2 Concrete and Structural Steel All interior concrete and structural steel surfaces in the containment structure were given a coating suitable for service under DBA conditions.
The steel floor grating is galvanized.
PROVIDED FOR INFORMATION ONLY 5.2-62 (NO CHANGES TO THIS PAGE)
PROVIDED FOR INFORMATION ONLY 5.2-62 (NO CHANGES TO THIS PAGE)


BVPS-1-UPDATED FSAR                     Rev. 0 (1/82)                   ~.
BVPS-1-UPDATED FSAR Rev. 0 (1/82)
~.
TABLE 5.2-16 I
TABLE 5.2-16 I
PIPE BREAK LOCATIONS "
PIPE BREAK LOCATIONS "
Main Steam Lines                           Feedwater Lines 32-SHP-58     16-WFPD-22     16-WFPD-23   16-WFPD-24 Location              32-SHP-56 32-SHP-57 3             3           199             98           140 Terminal Points                  3 300          400          244 UI         1280I         188     l 200 84       204           204         h7-203           144 110       14+ 184 Point of Maximum Primary + Secondary Stress                                                                     24503 None         None         44ene 203       -None 1270)   -Nene 188 l Point Where                    None P+S> .8     (S +S)h                                                    307             110
Main Steam Lines Feedwater Lines Location 32-SHP-56 32-SHP-57 32-SHP-58 16-WFPD-22 16-WFPD-23 16-WFPD-24 Terminal Points 3
                                                                                        ~
3 3
f*I 203r2)         102 o
199 98 140 UI 1280I 188 l
203(2)       20  (2)         y          144(2)
200 300 400 244 Point of Maximum 84 204 204 h7-203 144 110 14+ 184 Primary + Secondary Stress 24503 Point Where None None None 44ene 203
P>.8 Allowable =                                           (*       307             110           143(2)
-None 1270)
      .8(1.2) S,                     None None                         None         None Point Where                      one      None Ma                                                                       5              h4            43      i Total Points ~                   3         43           X3 Total Areas                       3         43           ) 51           X'\1           i'Al 30) 3 '\1 301 l
-Nene 188 l
301           40)
P+S>.8 (S
Where:   P = Primary Stress S = Secondary Stress Sh' S a are defined in ASME III NC3611 M- b'iLL thc caceptien cf "t 180 cn 15-5T"O-21 011 pcint             listed Obcvc cre Note:
+S) 307 110 a
at cibcuc.
h
III+*+ Because of the proximity of two points, the area between the two points                   l is considered one break area.
~
f*I 203r2) 102 (2) y 144(2) 203(2) 20 o
P>.8 Allowable =
(*
307 110 143(2)
None
.8(1.2) S, Point Where one None None None None Ma Total Points ~
3 43 X3 5
h4 43 i
Total Areas 3
43
) 51 X'\\1 i'Al 3 '\\1 l
301 40) 30) 301 Where:
P = Primary Stress S = Secondary Stress Sh' S are defined in ASME III NC3611 a
Note:
M-b'iLL thc caceptien cf "t 180 cn 15-5T"O-21 011 pcint listed Obcvc cre at cibcuc.
III+*+ Because of the proximity of two points, the area between the two points l
is considered one break area.
1 of 1
1 of 1


BVPS-1-UPDATED FSAR                 Rov.             7 (1/89)                             ,
BVPS-1-UPDATED FSAR Rov.
preclude the system's ability to perform its function.
7 (1/89) not preclude the system's ability to perform its function.
The not                                                                                                                        The pcsitions of these valves             are   indicated     in the               control             room.
The pcsitions of these valves are indicated in the control room.
instrumentation, control and             electrical       equipment                   of             this             system and conforms     to the requirements of Institute for Electrical Electronic Engineers (IEEE) 279-1971 Criteria for Protection Systems for Nuclear Power Generating Stations and IEEE 308-1971 Criteria for Class lE Power Systems for Nuclear Power Generating Stations.
The instrumentation, control and electrical equipment of this system conforms to the requirements of Institute for Electrical and Electronic Engineers (IEEE) 279-1971 Criteria for Protection Systems for Nuclear Power Generating Stations and IEEE 308-1971 Criteria for Class lE Power Systems for Nuclear Power Generating Stations.
10.3.5.2       Description 10.3.5.2.1   Condensate and Feedwater Systems Condensate    is withdrawn from the condenser hotwella by two half-size capacity motor-driven condensate pumps.
10.3.5.2 Description 10.3.5.2.1 Condensate and Feedwater Systems is withdrawn from the condenser hotwella by two half-size Condensatemotor-driven condensate pumps.
The pumps discharge into a common    header    which carries the   condensate       through two steam jet air ejector condensers       arranged   in parallel and     through one gland steam condenser.      A flow control valve   and   a bypass     around the gland steam condenser ensure that no more than Downstream        maximum design flow passes of the gland steam through the gland steam condenser.
The pumps discharge into a capacityheader which carries the condensate through two steam jet air common ejector condensers arranged in parallel and through one gland steam A flow control valve and a bypass around the gland steam condenser.
condenser,     the common header divides into two lines which carry the condensate through the tube side of two trains of heat exchangers arranged in parallel, each consisting of one heaterthrough                        drain cooler                       6),
condenser ensure that no more than maximum design flow passes through the gland steam condenser.
and each five   low pressure feedwater headers                 (No. 2 half-capacity.         The effluent from each train combines into a common suction header for the two half-size design capacity steam generator feedpumps.       Mar.,a1   valves permit isolation of one train of heaters for maintenance without a station shutdown.
Downstream of the gland steam condenser, the common header divides into two lines which carry the through the tube side of two trains of heat exchangers condensate arranged in parallel, each consisting of one heater drain cooler and five low pressure feedwater headers (No.
The condenser hotwell is designed to operate at normal level such that 4     minutes of condensate flow (71,000 gal) is available                                                             to plant the     condensate     pumps.         A   200,000                 gal         turbine supply demineralized water storage           tank floats on the system. Each of the condensate       pumps is rated at 9,700 gpa at two vertical barrel-type 1,078 ft TDH.         Minimum     flow   of approximately                     3,000 gpa total for each of the two condensate             pumps     is   maintained                         by an orifice the   gland       steam                 condenser.                         The measuring device downstream            of orifice measuring device operates the recirculation valve as shown in Figure 10.3-4.
2 through 6),
Two   half-size steam generator feedpumps, each rated at 15,200 gpm and 1,700 ft TDH, are furnished to supply feedwater to the three steam generators.         Each feedpump is equipped with two 4,000 hp electric motor drivers in tanden.                 Minimum flow for each pump is maintained by administrative control and an flow            automatic         measuring nozzles, recirculation control   and   alarm   system,     consisting     of:
each half-capacity.
totalizer,     controller,         and     recirculation valves.                                                   The flow recirculation valvas normally             maintain     a minimum               flow                   of       8,000   gpa per pump. Feedwater leaves the first-point heaters at 440*F.
The effluent from each train combines into a common suction header for the two half-size design capacity steam generator feedpumps.
The steam generator feedpumps discharge through two half-eize                                                         design capacity high     pressure   feedwater       heaters         (No.             1)       ,               arranged         in parallel, to a common discharge header for distribution to thevalves,                                                  steam generators     through     individual       feedwater                 flow         control 10.3-14 PROVIDED fur INFORMATION ONLY (NO CHANGES TO THIS PAGE)
Mar.,a1 valves permit isolation of one train of heaters for maintenance without a station shutdown.
The condenser hotwell is designed to operate at normal level such that 4
minutes of condensate flow (71,000 gal) is available to supply the condensate pumps.
A 200,000 gal turbine plant demineralized water storage tank floats on the system.
Each of the two vertical barrel-type condensate pumps is rated at 9,700 gpa at 1,078 ft TDH.
Minimum flow of approximately 3,000 gpa total for each of the two condensate pumps is maintained by an orifice measuring device downstream of the gland steam condenser.
The orifice measuring device operates the recirculation valve as shown in Figure 10.3-4.
Two half-size steam generator feedpumps, each rated at 15,200 gpm furnished to supply feedwater to the three and 1,700 ft TDH, are steam generators.
Each feedpump is equipped with two 4,000 hp electric motor drivers in tanden.
Minimum flow for each pump is maintained by administrative control and an automatic recirculation control and alarm
: system, consisting of:
flow measuring nozzles, flow totalizer, controller, and recirculation valves.
The recirculation valvas normally maintain a minimum flow of 8,000 gpa per pump.
Feedwater leaves the first-point heaters at 440*F.
steam generator feedpumps discharge through two half-eize design The capacity high pressure feedwater heaters (No.
: 1),
arranged in
: parallel, to a common discharge header for distribution to the steam generators through individual feedwater flow control
: valves, 10.3-14 PROVIDED fur INFORMATION ONLY (NO CHANGES TO THIS PAGE)


BVPS-1-UPDATED FSAR                     Rov. 4 (1/86)                     l positioned by- the three-element feedwater control system for each steam generator.                   A manual bypass around each first-point heater                                           i allows isolation of these heaters for maintenance without a station                                                           '
BVPS-1-UPDATED FSAR Rov. 4 (1/86) positioned by-the three-element feedwater control system for each steam generator.
shutdown.                 During low power operation or hot shutdown, when feedwater flow is below 20 percent of design flow, a bypass valve                                                             i around each feedwater control valve provides steam generator level and feedwater flow control.-                                             The automatic control of the steam                   ,
A manual bypass around each first-point heater i
generator water level at low power using the feedwater bypass valve is also discussed in section 7.7.1.7.
allows isolation of these heaters for maintenance without a station shutdown.
INSERT ----->                                                                                                                   l An automatic -bypass is used to bypass all the low pressure heaters between the condensate pump discharge and the steam generator feedpump suction in the event of a sudden load reduction. This enables .the_ condensate pumps to supply adequate suction to the steam generator feedpumps.
During low power operation or hot
Drains from the moisture separator reheater units and the No. 1 and No. 2 feedwater heaters are collected in the heater drain tank and' pumped into the suction of the steam generater feedpump6 by one of the two. full-capacity heater drain pumps.                                         Drains from heater No. 3 cascade to heater No. 4 and from heater No. 4 to heater No. 5 and from heater No. 5 through the drain cooler to the condenser. Drains from heater No.                     6         flow directly to the condenser.- An alternats drain- line is provided directly to the condenser from the heater drain tank and-feedwater heaters Nos. 1, 3, 4, 5 and 6.
: shutdown, when feedwater flow is below 20 percent of design flow, a bypass valve i
Condensate -from the condenser hotwell may be discharged- under administrative control through either a- double valved connection line to the circulating water line, if activity levels permit, or
around each feedwater control valve provides steam generator level and feedwater flow control.-
              -through a- normally closed- connection to the liquid waste disposal-system (section 11.2.4).                                             The condensers may also be emptied by pumping,               with _ the             condensate                 pumps, into the turbine plant domineralized water storage tank. This tank also supplies makeup to the condenser hotwelle.-                                           During . normal- operation, _ discharge of condensate to the -tank and makeup from the tank are automatically-controlled by the hotwell level.-
The automatic control of the steam generator water level at low power using the feedwater bypass valve is also discussed in section 7.7.1.7.
Chemical- -feed equipment is- used to add chemical solutions to the L             -discharge- of the condensate pumps in the condensate and feedwater-systems.               The chemicals control residual oxygen content, maintain.pH-at levels specified ini the BVPS-1 Chemistry Manual and inhibit corrosion so as to reduce pickup of metal by the feedwater.
l INSERT ----->
Solutions are mixed and stored in covered feedtanks.                                                     The solutions are pumped               into   the main             condensate           system by motor-driven             positive
An automatic -bypass is used to bypass all the low pressure heaters between the condensate pump discharge and the steam generator feedpump suction in the event of a sudden load reduction.
              -displacement pumps with manually adjustable stroke.-
This enables.the_ condensate pumps to supply adequate suction to the steam generator feedpumps.
10.3.5.2.2             Auxiliary Feedwater Systen l-               The               steam generator -auxiliary                           feedpumps- are used as an emergency l-               source of feedwater supply to the steam generators.                                                             They are
Drains from the moisture separator reheater units and the No. 1 and No.
: i.             Erequired to ensure safe shutdown in- the event of a main turbine l
2 feedwater heaters are collected in the heater drain tank and' pumped into the suction of the steam generater feedpump6 by one of the two. full-capacity heater drain pumps.
Drains from heater No. 3 cascade to heater No.
4 and from heater No. 4 to heater No. 5 and from heater No. 5 through the drain cooler to the condenser.
Drains from heater No.
6 flow directly to the condenser.- An alternats drain-line is provided directly to the condenser from the heater drain tank and-feedwater heaters Nos.
1, 3,
4, 5 and 6.
Condensate -from the condenser hotwell may be discharged-under administrative control through either a-double valved connection line to the circulating water line, if activity levels permit, or
-through a-normally closed-connection to the liquid waste disposal-system (section 11.2.4).
The condensers may also be emptied by
: pumping, with _ the condensate
: pumps, into the turbine plant domineralized water storage tank.
This tank also supplies makeup to the condenser hotwelle.-
During. normal-operation, _ discharge of condensate to the -tank and makeup from the tank are automatically-controlled by the hotwell level.-
Chemical- -feed equipment is-used to add chemical solutions to the L
-discharge-of the condensate pumps in the condensate and feedwater-systems.
The chemicals control residual oxygen content, maintain.pH-at levels specified ini the BVPS-1 Chemistry Manual and inhibit corrosion so as to reduce pickup of metal by the feedwater.
Solutions are mixed and stored in covered feedtanks.
The solutions are pumped into the main condensate system by motor-driven positive
-displacement pumps with manually adjustable stroke.-
10.3.5.2.2 Auxiliary Feedwater Systen l-The steam generator -auxiliary feedpumps-are used as an emergency l-source of feedwater supply to the steam generators.
They are i.
Erequired to ensure safe shutdown in-the event of a main turbine l
10.3-15
10.3-15
?                                                                                                                                             _b
?
_b


BVPS-1 UFSAR THERMAL STRATIFICATION IN THE MAIN FEEDWATER PIPING Insert the following paragraph where indicated in Section 10.3.5.2.1
BVPS-1 UFSAR THERMAL STRATIFICATION IN THE MAIN FEEDWATER PIPING Insert the following paragraph where indicated in Section 10.3.5.2.1
      " Condensate and feedwater Systems," Page 10.3-15.
" Condensate and feedwater Systems," Page 10.3-15.
When a reactor trip occurs feedwater control valves are closed and auxiliary feedwater flow is initiated. Flow continues into the main feedwater piping downstream through the bypass valve. Continued flow through the bypass valve combines with cold auxiliary feedwater flow to cause thermal stratification in the downstream main feedwater lines. This stratification in the main feedwater lines can cause increased stress levels in the main feedwater piping and supports. Therefore, the bypass valve around each main feedwater control valve must be isolated above 30 percent power to prevent the possibility of increased stress levels resulting from thermal stratification.2 Add the following reference to the list of Section 10.3 references on Page 10.3-27:
When a reactor trip occurs feedwater control valves are closed and auxiliary feedwater flow is initiated.
: 2. Letter from J.D. Sieber (Duquesne Light Company) to A.W. De Agazio (Nuclear Regulatory Commission),  
Flow continues into the main feedwater piping downstream through the bypass valve. Continued flow through the bypass valve combines with cold auxiliary feedwater flow to cause thermal stratification in the downstream main feedwater lines. This stratification in the main feedwater lines can cause increased stress levels in the main feedwater piping and supports.
Therefore, the bypass valve around each main feedwater control valve must be isolated above 30 percent power to prevent the possibility of increased stress levels resulting from thermal stratification.2 Add the following reference to the list of Section 10.3 references on Page 10.3-27:
2.
Letter from J.D. Sieber (Duquesne Light Company) to A.W. De Agazio (Nuclear Regulatory Commission),


==Subject:==
==Subject:==
Main Feedwater Piping Elbow Cracking and Misalignment - TAC 79769 (June 1991).
Main Feedwater Piping Elbow Cracking and Misalignment - TAC 79769 (June 1991).


  . ~ . . . _ . . . . _          . ..__. _.          .      _ . - _ _ . . . - - _ . _ . .            ___      - - _ _ .    - . . . . . . . _ . _ . _ _ . _ . . . . _ _ _
. ~.
                  . 4 BVPS-1-UPDATED FSAR-                           Rov. 5 (1/87):
. 4 BVPS-1-UPDATED FSAR-Rov. 5 (1/87):
References for Section 10.3
References for Section 10.3 1.
: 1. -DLC NED Analysis 8700-21-5, Rev. O.                                               Addendum 1, dated June 1986, INSERT ----->
-DLC NED Analysis 8700-21-5, Rev. O.
l i
Addendum 1, dated June 1986, INSERT ----->
10.3-27
i 10.3-27
  ,-          . - ~ , . . , - -         , , , - - - - , , -                                - - - - ,
. - ~,.., - -


                                                                                                                                                                                                .r                                                    etv. e (1/st)
etv. e (1/st)
                                                                                                                                                                                '"'                        r.
.r r.
N-5 l C-w HvpRAttec type m [                                                                                 ''
N N-5 l C-w HvpRAttec type m [
N                                  .r.
.r.
Arracuto m ca m e wAu.                                                                   ,                      f                 ,-
Arracuto m ca m e wAu.
                                                                                                          /             '
f VERT. CONST
/
g
g
* VERT. CONST i                    e ss
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PEuETRAT                        /cg H4NGs a (TV#9                     8H A5 tes
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~~ cl3
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% CR***E w^ti 4 vEWT. CosaST.
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.N-S d E-W e4YDEAOL6C TM
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s N Cl
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VERTICAL CONSTRAINT                                 ,,
VERTICAL CONSTRAINT E w 4 n.s savoRAutic Cl7 l$ A '"._ _^ a_f.LL' wg ggy
E w 4 n.s savoRAutic Cl7 l$ A '"._ _^ a_f.LL' wg ggy                                             .- - Segg gg                                   TYPE BRACE (TYP)
.- - Segg gg TYPE BRACE (TYP)
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/
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^
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                                                                                                                                                                                                ,'                          /         eArnou " 7s
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                                                                                                                                                                                                          ,so
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7 eArnou " 7s l
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: 4. VERTICAL cortSTRangr N
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Latest revision as of 23:51, 14 December 2024

Responds to NRC Re Main Feedwater Piping Elbow Cracking & Misalignment.Temp & Displacement Instrumentation Installed at Certain Locations on Main Feedwater Piping Loops a & C.Marked-up FSAR Encl
ML20079C918
Person / Time
Site: Beaver Valley
Issue date: 06/14/1991
From: Sieber J
DUQUESNE LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RTR-REGGD-01.046, RTR-REGGD-1.046 TAC-79769, NUDOCS 9106260316
Download: ML20079C918 (16)


Text

s 4

8vP APV b VWPI bl3! OA hNpp*FO"1 PA 1W 7 0004 M*4 D Srf 3tB w. row

%., c,m.

mm" June 14, 1991 U.

S.

Nuclear Regulatory Commission Attn:

Document Control Desk Wushington, DC 20555

Subject:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769)

Ref: Letter from A.W.

DeAgazio (Nuclear Regulatory Commission) to J.D.

Sieber (Duquesne Light Company),

Subject:

Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769), April 17, 1991.

This letter provides a

response to the main feedwater system piping verificatio.'

requested in the referenced letter.

Each requested verification is presented followed by the actions taken to determine acceptability.

REQUESTED VERIFICATION Verification that the affected feedwater piping satisfies the licensing basis for plant piping.

ACTIONS A.

Design change 1684 replaced monoballs on the A and C main feedwater lines with passive (rigid box) supports during the eighth refueling outage.

B.

The operating manual procedures have been revised so that the main feedwater bypass regulating valves are normally closed above 30 percent power.

C.

With the above changes in design and operation, applicable p1pe rupture criteria in Regulatory Guide 1.46 can be satisfied at all power levels.

Applicable pipe rupture criteria will be incorporated into the UFSAR as shown in the Attaohment.

0

,0 9106260316 910614

\\\\

PDR ADOE 05000334 p

f'DR

1

.l LBeaver Valley ~ Power Station,-Unit No. 1 Docket'No. 50-334, License No. DPR-66

. Main Feedwater piping Elbow Cracking and Misalignment (TAC 79769)

Page 2 REQUESTED VERIFICATION

- Verification that the feedwater lines are free of binding or

' interference with-pipe-rupture restraints under all thermal conditions.

ACTIONS A.

Main _feedwater -piping was walked down at the completion of design change 1684 and replacement-of an elbow on the "C" loop.-

It has been verified that the lines are free of binding or interference with the pipe rupture restraints.

B.

Analytical evaluations of main feedwater pipe movement were reviewed to verify that spacing at pipe supports and rupture

-restraints are adequate under all thermal conditions.

This review entailed a comparison of existing gaps at restraints versus calculated dittolacements under all thermal conditions.

Under -stratified conditions, the piping will close gaps _at specific restraints.

This was incorporated in the. analyses and it has been determined that piping will remain within the design basis stress criteria under all thermal conditions.

C.

Temperature and displacement instrumentation has been installed at -certain locations on nain feedwater piping loops A

and C to_ gather more information and furtaer define.

Global Thermal Stratification effects.

Each temperature monitoring location has a minimum of three (3) thermocouples located at-the

top, bottom and on the side of-the pipe.

Each' ' displacement location has three-(3) lanyards to measure.

the-veritcal, lateral and axial deflections of the pipe.

Based upon the. actions summarized above, we have concluded that

-the ; main _feedwater piping has_ been restored to-a satisfactory 10,

- configuration for plant operation.

Should you have any questions regarding this

response, please contact Mr. Ken McMullen at_(412) 393-5214.

i L

Sincerely,

/.

D.

Sieber Vice President Nuclear Group-L Attachment i

cc:

Mr.

J.

Beall, Sr. Resident' Inspector Mr.

T.

T. Martin, NRC Region I Administrator Mr.

A.

W.

DeAgazio,-Project Manager Mr.

R. Saunders'(VEPCO) 1T4W W

'g-t

- +, + - -

t-N-b ig-w

KI"I'ACHMENI Beaver Valley Power Station, Unit No. 1 Main Feedwater Piping Elbow Cracking and Misalignment (TAC 79769)

Updated Final Safety Analysis Report Changes to Incorporate Regulatory Guide-1.46 Pipe Rupture Critoria h

L. W A E:.4

BVPS-1-UPDATED FSAR Rev. 1 (1/83)

The missile with the highest kinetic energy-to-impact area ratio

( KE/A ),

which is considered the most dertructive missile, is a propane bottle relief device

(".ype 3) with KE/A of 7656 ft-lb per square i-h.

The F E/ A of 9195 ft-lb per square inch for the design lasis missile compared to the maximum KE/A from Table 5.2-15 justifies the

" exclusion from further analysis" approach of the safety related equipment isolated by missile proof walls.

5.2.6.2 Exterior Missiles The containment has not been analyzed for exterior missiles generated by hypothetical aircraft accidents, due to the site being located more than 5 miles from any airport (Table 2.1-7 ).

Tornado generated missiles discussed in Section 2.7 include one potential missile equivalent to a 35-ft long wooden utility pole impacting at a velocity of 150 mph.

5.2.6.3 Criteria for Protection Against Dynamic Effects Associated with a Major Pipe Rupture The containment vessel and all essential equipment within the containment are adequately protected against the effects of blowdown jet forces and pipe whip resulting from a postulated pipe rupture of reactor coolant (Class

1),

main

steam, and feedwater (Class 2) lines.

The criteria for adequate protection permits limited damage when analysis or experiment demonstrates that:

1.

Leakage through the containment will not cause offsite dose consequences in excess of 10CFR part 100 guidelines.

2.

The minimum performance capabilities of the engineered safety systems are not reduced below that required to protect against the postulated break.

3.

A pipe break which is not a loss of reactor coolant will not cause a loss of reactor coolant or steam or feedwater line break.

Also, a reactor coolant system pipe break will not cause a steam-feedwatar system pipe break and vice versa.

This level of protection is assured by adherence to the following design criteria.

Placement of Piping and Comoonents The routing of pipe and the placement of components minimize the possibility of damage.

PROVIDED FOR INFORMATION ONLY 5.2-58 (NO CHANGES TO THIS PAGE)

f BVPS-1-UPDATED FSAR Rev. 1 (1/83) l The polar crane wall serves as a barrier between the reactor coolant loops and the containment liner.

In

addition, the cavity walls, various structural beams, the operating refueling floor, and the crane wall, enclose each reactor coolant loop into a separate compartment, thereby preventing an accident, which may occur in any loop, from affecting another loop or the containment liner.

The portion of the steam and feedwater lines within the containment have been routed behind barriers which separate these lines f rom all reactor coolant piping.

The barriers described above will withstand loadings caused by jet forces and pipe whip impact forces.

Other than for the Emergency Core Cooling System lines, which must circulate cooling water to the vessel, the engineered safety features are located outside of the crane wall.

The Emergency Core Cooling System lines are routed outside of the crane wall so that the penetrations are in the vicinity of the loop to which they are attached.

Supplemental Protection In those regions where the careful layout of piping and cannot offer adequate protection against the dynamic components restraints to effects associated with a postulated pipe rupture, prevent excessive pipe movement or special shielding is provided.

The careful layout of piping and components offers adequate protection against the dynamic effects associated with a

in the case of the main steam and postulated pipe rupture exceptcrane wall and the pressurizer surge feedwater lines outside the line.

In the case of the pressurizer surge line, a sufficient number of restraints are provided such that, following a single break, the unrestrained pipe movement of either end of the ruptured pipe about a plastic hinge formed at the nearest pipe whip restraint cannot impact any structcre, system or component important to safety.

The basis for selecting break locations in the main steam and feedwater systems, whose piping is similar to ASME Boiler and Pressure Vessel Code,Section III, Class 2 piping, is discussed belowv and is consistent with Regulatory Guide 1.46

" Protection Against Pipe Whip Inside Containment."

.Since the probability of rupture is strongly related to stress, only a

limited number of break locations are postulated.

Supplemental protection is provided on the main steam and feedwater lines for breaks at e-1 locations wh::: the trern cacced: 90 p : cent of th: :llewable strest.

A =ini=u= cf three bre:h lec: tion: ver p::tul:ted by the fellering criteria:

d9 scribed below:

1.

At the two terminal points 2.

At the point of maximum primary plus secondary stress 5.2-59

BVPS-1-UPDATED PSAR Rev. 1 (1/83) h 3.

At any other point where the primary plus secondary stress exc >ds 80 percent of its allowable; i.e.,

0.8 (S

+S Or the cccendary ctrccc cxcccds-00 pcr cat

)f o

it:

211c'c?2b le ;

i.e.,

0.8 C Or the primary ctrecc execcdc 90 perecnt of it: _ l let?2b ic ;

i O 09 U 2 Q*

Each three There are The main steam and feedwater piping (similar to ASME Boiler and Pressure Vessel Code III, Class 2 piping) requires pipe break restraints in order to protect the integrity of the containment lines.

Of the six piping runs -hve-runc cach contain a total of s

or more postulated break points.

Thc brcch locatienc 2re picked "Scre there ic 2 charp change ir ctrecc icvel c2cng the 1-eng th cf pipe.

There cec =0 te 50 ne reasenchle

.cthed to-- p i c h one --- pc int vercuc ancther Sen the ctrccc icvci docc not ecry apprecichly cleng the pipe run.

Table 5.2-16 gives the pipe break locations postulated for the three main steam and three main feedwater pipe runs inside the containment building.

The loop A main steam line contains three break points and/or areas.

Figures 5.2-33 through 5.2-38 coordinate the point numbers, given in Table 5.2-16 to a location along the pipe run.

The restraint locations for main steam lines and for main feedwater lines are provided in Figures 5.2-39 and 5.2-40 respectively.

Restraint locations are based upon what were, at the time of design fixing, the prevailing criteria for number and type of break.

Restraints offer good supplemental protection since pipe displacements are minimized and large kinetic energies are prevented.

The placement of the restraints will prevent excessive pipe displacements in the event of either a longitudinal split or circumferential break, or both, depending on the state of stress in the line.

In the area where the feedwater and the main steam piping the containment shell, the liner is also protected by penetrate an overlay of 1 1/2 inch thick quenched and tempered steel plate.

Methods of Analysir.

Analyses are performed for pipe impact and jet impingement.

In

addition, major equipment supports are analyzed to ensure adequacy under postulated pipe rupture loads transmitted by attached piping.

For the purposes of design, unless otherwise stated, the pipe break event is considered a faulted condition, and the pipe, its restraint or barrier, and the structure to which it is attached are designed accordingly.

l 5.2-60

BVPS-1-UPDATED FSAR Rev. 1 (1/83)

Restraints which require plastic deformation are based on 50 parcent of ultimate strain.

The forces associated with both longitudinal and circumferential ruptures are considered in the design of supports and restraints in order to ensure continued integrity of vital components and engineered sa fety features.

The break area for both postulated break types is the cross-sectional area of the pipe.

The break length for the

,ostulated longitudinal breaks is assumed to be equal to twice the pipe diameter.

The analysis takes advantage of limiting factors on the blowdown thrust

force, such as line
friction, flow restrictors, pipe configuration, etc.

A rise time is applied to the thrust force to simulate the crack opening time.

A one millisecond rise time is assumed for circumferential breaks.

For longitudinal splits, a rise time is computed based on the growth of a crack from a critical length to a

length of two pipe diameters at a

propagation rate of 500 ft/second.

Pipe Restraints The restraints are designed with a gap sufficient to prevent interference with the normal thermal dynamic motion of the lines.

This permits the pipe to acquire kinetic energy which must be dissipated upon impact into the restraint.

This energy was conservatively set equal to the product of peak thrust times displacement.

No energy disstpation mechanisms operating prior to

impact, such as plastic deformation in the
pipe, were considered.

Static analyses of the deformation of the restraints and bolts provided the force displacements characteristics of the restraints.

The area (energy) under this force-displacement curve was matched to the. kinetic energy of the impacting pipe to determine the deformation and load.

Based on

recent, more detailed analyses, the conservatism of this design approach has been proven.

Figures 5.2-39 and 5.2-40 show the configurations of typical piping restraints and locations of such restraints for the main steam system and feedwater system, respectively.

Figures 5.2-41 and 5.2-42-show the similar information for the pressurizer surge line.

The restraints consist of a circular arch (or yoke) and a welded base support structure that is bolted to a supporting wall.

These restraints are designed so

that, by the use of self-adjusting shims, the gap between the pipe and the inner surface of the restraint is kept as small as practicable while still allowing free thermal expansion of the pipe during plant operation.

PROVIDED FOR INFORMATION ONLY 5.2-61 (NO CHANGES TO THIS PAGE)

BVPS-1-UPDATED FSAR Rev. 1 (1/83)

The barrier provided near the containment penetration is attached to the pipe penetration sleeve.

Equipment Supports The internal structural system of the containment is designed to mitigate loading due to rupture in the main reactor coolant lines and the main steam and feedwater lines.

Incident rupture is considered in only one line at a time.

The support system is designed to preclude damage to or rupture of any of the other lines as a result of the incident.

The snubber and key systems are designed to deliver rupture thrusts on the steam generator into the internal structural system.

In determining the steam-generator support reactions, the system is reduced to a dynamic model consisting of a suitable number of masses and resistance elements.

The dynamic problem is solved by numerical methods, using a thrust time history as loading.

Resistance, dynamic amplification of the thrust, and rebound forces are calculated as a function of time.

The reactor vessel and support system is similarly treated.

l 5.2.6.4 Pipe Whip Analysis The analysis of the restrained piping within the containment was completed and the fabrication of restraints begun before any officially acceptable criteria for analysis was published.

Subsequent to the completion of the analysis, analytical methods and criteria to be used in determining pipe whip analysis was transmitted to DLC from the AEC.

The analytical methods and criteria are provided in Attachment A to Section 5.2, " Pipe Whip Analysis Guidelines".

The analytical methods and criteria used were similar to, but not identical with, those outlined in Attachment A.

To facilitate a comparison, the original criteria is provided in Attachment B using the format of Attachment A and a point-by-point comparison is presented.

Emphasis is placed on those criteria which differ.

5.2.7 Corrosion Protection and Coatj gg, 5.2.7.1 Steel Liner The exterior of the steel liner is not coated because it is in intimate contact with the concrete and has adequate protection from corrosion.

The interior of the stsal liner has an inorganic zine coating with a

white epoxy topcoating which provides protection for both normal operating and accident conditions.

5.2.7.2 Concrete and Structural Steel All interior concrete and structural steel surfaces in the containment structure were given a coating suitable for service under DBA conditions.

The steel floor grating is galvanized.

PROVIDED FOR INFORMATION ONLY 5.2-62 (NO CHANGES TO THIS PAGE)

BVPS-1-UPDATED FSAR Rev. 0 (1/82)

~.

TABLE 5.2-16 I

PIPE BREAK LOCATIONS "

Main Steam Lines Feedwater Lines Location 32-SHP-56 32-SHP-57 32-SHP-58 16-WFPD-22 16-WFPD-23 16-WFPD-24 Terminal Points 3

3 3

199 98 140 UI 1280I 188 l

200 300 400 244 Point of Maximum 84 204 204 h7-203 144 110 14+ 184 Primary + Secondary Stress 24503 Point Where None None None 44ene 203

-None 1270)

-Nene 188 l

P+S>.8 (S

+S) 307 110 a

h

~

f*I 203r2) 102 (2) y 144(2) 203(2) 20 o

P>.8 Allowable =

(*

307 110 143(2)

None

.8(1.2) S, Point Where one None None None None Ma Total Points ~

3 43 X3 5

h4 43 i

Total Areas 3

43

) 51 X'\\1 i'Al 3 '\\1 l

301 40) 30) 301 Where:

P = Primary Stress S = Secondary Stress Sh' S are defined in ASME III NC3611 a

Note:

M-b'iLL thc caceptien cf "t 180 cn 15-5T"O-21 011 pcint listed Obcvc cre at cibcuc.

III+*+ Because of the proximity of two points, the area between the two points l

is considered one break area.

1 of 1

BVPS-1-UPDATED FSAR Rov.

7 (1/89) not preclude the system's ability to perform its function.

The pcsitions of these valves are indicated in the control room.

The instrumentation, control and electrical equipment of this system conforms to the requirements of Institute for Electrical and Electronic Engineers (IEEE) 279-1971 Criteria for Protection Systems for Nuclear Power Generating Stations and IEEE 308-1971 Criteria for Class lE Power Systems for Nuclear Power Generating Stations.

10.3.5.2 Description 10.3.5.2.1 Condensate and Feedwater Systems is withdrawn from the condenser hotwella by two half-size Condensatemotor-driven condensate pumps.

The pumps discharge into a capacityheader which carries the condensate through two steam jet air common ejector condensers arranged in parallel and through one gland steam A flow control valve and a bypass around the gland steam condenser.

condenser ensure that no more than maximum design flow passes through the gland steam condenser.

Downstream of the gland steam condenser, the common header divides into two lines which carry the through the tube side of two trains of heat exchangers condensate arranged in parallel, each consisting of one heater drain cooler and five low pressure feedwater headers (No.

2 through 6),

each half-capacity.

The effluent from each train combines into a common suction header for the two half-size design capacity steam generator feedpumps.

Mar.,a1 valves permit isolation of one train of heaters for maintenance without a station shutdown.

The condenser hotwell is designed to operate at normal level such that 4

minutes of condensate flow (71,000 gal) is available to supply the condensate pumps.

A 200,000 gal turbine plant demineralized water storage tank floats on the system.

Each of the two vertical barrel-type condensate pumps is rated at 9,700 gpa at 1,078 ft TDH.

Minimum flow of approximately 3,000 gpa total for each of the two condensate pumps is maintained by an orifice measuring device downstream of the gland steam condenser.

The orifice measuring device operates the recirculation valve as shown in Figure 10.3-4.

Two half-size steam generator feedpumps, each rated at 15,200 gpm furnished to supply feedwater to the three and 1,700 ft TDH, are steam generators.

Each feedpump is equipped with two 4,000 hp electric motor drivers in tanden.

Minimum flow for each pump is maintained by administrative control and an automatic recirculation control and alarm

system, consisting of:

flow measuring nozzles, flow totalizer, controller, and recirculation valves.

The recirculation valvas normally maintain a minimum flow of 8,000 gpa per pump.

Feedwater leaves the first-point heaters at 440*F.

steam generator feedpumps discharge through two half-eize design The capacity high pressure feedwater heaters (No.

1),

arranged in

parallel, to a common discharge header for distribution to the steam generators through individual feedwater flow control
valves, 10.3-14 PROVIDED fur INFORMATION ONLY (NO CHANGES TO THIS PAGE)

BVPS-1-UPDATED FSAR Rov. 4 (1/86) positioned by-the three-element feedwater control system for each steam generator.

A manual bypass around each first-point heater i

allows isolation of these heaters for maintenance without a station shutdown.

During low power operation or hot

shutdown, when feedwater flow is below 20 percent of design flow, a bypass valve i

around each feedwater control valve provides steam generator level and feedwater flow control.-

The automatic control of the steam generator water level at low power using the feedwater bypass valve is also discussed in section 7.7.1.7.

l INSERT ----->

An automatic -bypass is used to bypass all the low pressure heaters between the condensate pump discharge and the steam generator feedpump suction in the event of a sudden load reduction.

This enables.the_ condensate pumps to supply adequate suction to the steam generator feedpumps.

Drains from the moisture separator reheater units and the No. 1 and No.

2 feedwater heaters are collected in the heater drain tank and' pumped into the suction of the steam generater feedpump6 by one of the two. full-capacity heater drain pumps.

Drains from heater No. 3 cascade to heater No.

4 and from heater No. 4 to heater No. 5 and from heater No. 5 through the drain cooler to the condenser.

Drains from heater No.

6 flow directly to the condenser.- An alternats drain-line is provided directly to the condenser from the heater drain tank and-feedwater heaters Nos.

1, 3,

4, 5 and 6.

Condensate -from the condenser hotwell may be discharged-under administrative control through either a-double valved connection line to the circulating water line, if activity levels permit, or

-through a-normally closed-connection to the liquid waste disposal-system (section 11.2.4).

The condensers may also be emptied by

pumping, with _ the condensate
pumps, into the turbine plant domineralized water storage tank.

This tank also supplies makeup to the condenser hotwelle.-

During. normal-operation, _ discharge of condensate to the -tank and makeup from the tank are automatically-controlled by the hotwell level.-

Chemical- -feed equipment is-used to add chemical solutions to the L

-discharge-of the condensate pumps in the condensate and feedwater-systems.

The chemicals control residual oxygen content, maintain.pH-at levels specified ini the BVPS-1 Chemistry Manual and inhibit corrosion so as to reduce pickup of metal by the feedwater.

Solutions are mixed and stored in covered feedtanks.

The solutions are pumped into the main condensate system by motor-driven positive

-displacement pumps with manually adjustable stroke.-

10.3.5.2.2 Auxiliary Feedwater Systen l-The steam generator -auxiliary feedpumps-are used as an emergency l-source of feedwater supply to the steam generators.

They are i.

Erequired to ensure safe shutdown in-the event of a main turbine l

10.3-15

?

_b

BVPS-1 UFSAR THERMAL STRATIFICATION IN THE MAIN FEEDWATER PIPING Insert the following paragraph where indicated in Section 10.3.5.2.1

" Condensate and feedwater Systems," Page 10.3-15.

When a reactor trip occurs feedwater control valves are closed and auxiliary feedwater flow is initiated.

Flow continues into the main feedwater piping downstream through the bypass valve. Continued flow through the bypass valve combines with cold auxiliary feedwater flow to cause thermal stratification in the downstream main feedwater lines. This stratification in the main feedwater lines can cause increased stress levels in the main feedwater piping and supports.

Therefore, the bypass valve around each main feedwater control valve must be isolated above 30 percent power to prevent the possibility of increased stress levels resulting from thermal stratification.2 Add the following reference to the list of Section 10.3 references on Page 10.3-27:

2.

Letter from J.D. Sieber (Duquesne Light Company) to A.W. De Agazio (Nuclear Regulatory Commission),

Subject:

Main Feedwater Piping Elbow Cracking and Misalignment - TAC 79769 (June 1991).

. ~.

. 4 BVPS-1-UPDATED FSAR-Rov. 5 (1/87):

References for Section 10.3 1.

-DLC NED Analysis 8700-21-5, Rev. O.

Addendum 1, dated June 1986, INSERT ----->

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