ML20137K998
| ML20137K998 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 06/15/1994 |
| From: | FLORIDA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20137K821 | List:
|
| References | |
| FOIA-96-485 JPN-PSL-SENP-94, JPN-PSL-SENP-97-021, JPN-PSL-SENP-97-21, NUDOCS 9704070135 | |
| Download: ML20137K998 (10) | |
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1 FLORIDE POWER & LIGET CO i
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R&FETY ETALUETION 1
J 5 REMOTING TEE AUTOMETIC CONTROL FUNCTION FOR I-TCT-14-43 j i i
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i I JPN-FSL-SEEF-94-021 l
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BINDER 96-485 PDR
JPN-PSL-SENP-94-021 ,
REVISION 1 PAGE 2 OF 10 REVIEW AND APPROVAL RECORD ST. LucIE tm!T 2 PLANT TITLE REMOVING TME AUTOMATIC CONTP6L FlatCTION FOR I-TCV-14-48 LEAD DISCIPLINE NECHANICAL ENGINEERING ORGANIZATION PRODUCTION ENGINEERING GROUP REVIEW / APPROVAL:
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- For Centracter. Evels As Deterstand Dy Projects ** Review laterface As A Rio the All 10CFR$4.5 taale and PLAs FR P W ECTS APPROVAL:
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JPN-PSL-SEMP=94-021 REVISION 1 PAGE 3 OP 10 TABLE OF CONTENTS
'i SECTION 212LE R&gE l
-- Cover 1 l
- Review and Approval Record 2
- Tanle of contents 3 l
- Abstract . 4 1.0 Purpose and Descr5ption 5 2.0 Licensing Requirements. 5 3.0 Evaluation 6 4.0 Failure Modes and Effects Analysis 7 5.0 Plant Restrictions 7
- 6. Effect on Technical Specifications 7
. 7.0 Unreviewed Safety Question S
'! Dstermination s.0 Actions Required s 9.0 Referenons 10 l
- NQ l Attachments 1.0 PSL-2 Accident Flowrate Requirements (1 page)
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6 JPN-P8L-8ENP-94-021 '
REVISION 1 PAGE 4 OF 10 ABSTRicT l
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During the performance of In-Service Testing stroke time testing, I-TCV-14-45, a temperature control valve in the St. Lucie Unit 2 Intake ,
cooling Water (ICW) system failed to demonstrate repeatable stroke l l time results. Nonconformance Report (NCR) #2-612 was generated as a l l
i result of this event.
The purpose of this safety evaluation is to. demonstrate that the 2B ICW system is. capable of performing its intended safety function while I-TCV-14-4B is clamped in a predetermined condition. Valve I-TCV ,
4B is automatically controlled to maintain component cooling water '
(CCW) temperatures during power operation. Valve I-TCV-14-4B will be ,
l clamped such that it is in a locked position to provide sufficient )
flow through the 28 CCW heat.aw h== gar during accident conditions. j valve I-TCV-14-4B is required to be open during all operational modes. '
During Design Basis Accident conditions, I-TCV-14-4B opens further to permit increased ICW flow through the 23 CCW heat e**haager. I-TCV-14-43 nerforms the safety function of re-positioning from the Normal op. - sg throttle position (Design Flow = S,250 gym) to Emergency throttle position (Design Flow = 14,500 gpe).
This safety evaluation provides an assessment of the affects on a safety related system, and therefore, is classified as safety related.
This evaluation concludes that oparation of the plant with I-TCV-14-43 ,
maintained in the clamped open throttle position, during power l operation, does not represent an unreviewed safety question as defined 1 in 10CFR50.59, does not require a change to plant Techsical specifications and does not adversely affect plant operatton or ;
safety.
Revision 1 A clarification is provided to address changes in ICW system performance (i.e. fouling, pump performance changes, etc) before the l next scheduled outage. This is addressed by addition of a curve of a i ICW accident flowrate requirements through a CCW heat exchanger vs ICW l inlet temperatures, which can be used to demonstrate operability of ,
the ICW system at accident flowrates below 14,500 gpa. This revision l has no effect on the conclusions of the safety evaluation.
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(a JPW-PSI,-SEMP-94-021 REVISION 1 PAGE 5 OF 10 1.0 PURPOSE RED DESCRIPTION I The purpose of this safety evaluation is to demonstrate that Temperature control valve I-TCV 44-45 is capable of performing its design functions while aligned in the clamped open throttle position.
I-TCV-14-43 automatically controls outlet water flow fro *. the CCW heat r exchanger. The valve, in the new configuration, will remain clamped l in an open throttle position. This configuration may remain in effect l until the next scheduled outage.
i j' The clamped open position is expected to increase flow to the Component cooling Water (CCW) heat exchangers thereby reducing flow to the other branches supplied by the Intake cooling Water (ICW) system, 3
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including circulating cooling water pumps lube water supply header, j8 turbine cooling water heat exchangers, the hypochlorite system and the open blowdown cooling heat exchangers.
1 2.o KICENSING.1EDVIRE MNTS Technical snacifications Technical Specification 4.0.5, surveillance requirements for inservice inspection and testing of ASME Code Class Snents, is applicable to l valve I-TCV-14-48. This surveillance requirements for this technical specification remain satisfied since the valve has been placed in the open aosition and therefore has completed its safety function.
ZS&R valve I-TCV-14-4B is described in section 9.2.1.2, page 9.2-2 of the FSAR as follows:
" Butterfly valves I-TCV-14-4A and 48, (otm in each header), located at the outlet of the composant cooling water beat ==*=ayne, s . . i.
l automatically control outlet water flow from the aw*magne." ^'
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The FSAR also evaluates I-TCV-14-4B in a Failure Modes & Effects Analysis (FEMA) on FSAR page 9.2-24.
A functional requirement of safety related air operated valves is described is Section 9.3.1.3, page 9.3-2 of the FSAR as follows:
" safety related air operated valves are- designed to fail in the position required to perform their safety function in the event a loss cf air supply occurs." I-TCV-14-4B is designed to fail in the full open position.
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I JPN-PSL-8ENP-94-021 ,
REVISION 1 PAGE 6 0F 10 3.0 ET1LtT& TION
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3.1 Analysis of Effects on Safety
! Valve I-TCV-14-4B is an air operated control valve which changes i position based on the outlet temperature of the 28 CCW he.t exchanger.
1 The positioner operates within a limited range. Durirq a DBA, it
{ performs a safety function to the extent it controls cooling water 4 flow from the intake cooling watsr system to the 28 CCW heat
! exchanger. One of two CCW heat exchangers is required to provide j cooling water ficw for one of two CCW trains. One safety train is
! required to mitigate a design bases event. The proposed configuration l
would clamp the valve in a throttled position, which ensures (based on
! system conditions at that time) the required acciduc fle** of 14,500 8 l gym is available to the 28'CCW heat exchanger. In xeasing the f flowrate of the ICW system .in the normal operating configuration will i not cause the 2B ICW or 2C ICW pumps to exceed maximum flowrate limits j (i.e., pump run-out). The ICW system has installed restriction i orifices to prevent pump runout. A postulated failure of the valve to l ' fail in the close" position, as analyzed in the FEMA, is les3 likely
- to occur.
Attachment 1 is provided to address changes in ICW system performance j (i.e. fouling, pump performanam changes, etc) before the next
- scheduled outage. The attachment is a curve of ICW accident flowrate i requirements through a CCW heat exchanger vs ICW inlet temperatures, j whj " wn be used to demonstrate operability of the ICW system at 8 j acc m ... flowrates below 14,500 gps. The curve is from Reference 5 i and is based on a heat transfer coefficient of 300 BTU /ER-FT *F.
This heat transfer coefficient was selected based on past and of cycle performance Lasting (Ref. 7, page 25 and Ref. 8, pages 10 and 11) of 4
St. Lucie Unit 2 ccW heat exchangers.
The clamp has been designed such that the valve remains in the initial ,
throttled position required to ensure the post-accident flow rate of 14,500 gym. The clamp does not negatively impact the integrity of the j
! valve, piping system or affected structures. Refer to calculation PSL-2FSC-94-011 for the design evaluation of the clamp.
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JPN-PSI,-SENP-94-021 l REVISION 1 i PAGE 7 0F 10 i
j 3.2 Analysis of Effects on System Performance i
! The clamped open throttle position is expected to increase the flow to
- the CCW heat exchangers. BacMpressure established by the valve in its i normal throttled position is necessary to maintain desired flow rates to the non-safety relcted portions of the ICW system. While not a safety concern, there is an impact on balance-of-plant operation. The i reduction of flow to the TCW heat exchangers results in a degradation l in the ability of the heat exchangers to remove the heat loads from j the turbine-ganerator. Further, less cooling margin is available and
! the turbine-generatcr will become more sensitive to fluctuations in heat load or ICW tesperature. It will be necessary to enhance the monitoring of turbine-generator operating temperatures and ensure the l procedural and ma..utacturer'.s guidelines are not exceeded. The *
! reduction of cooling margin will reduce the time available for i compensatory measures, especially in the event of the loss of the "A" l ICW pump.
i Other systems affected by the change in flow balance of the ICW system l are the Open Blowdown Cooling system heat exchangers, the hypochlorite
! system and the ICW lube water header which supplies the Circulating l Water pumps. These systems will be monitored to ensure the change in
- flow rate does not adversely affect system performance. Reduced flow i
rates could hinder the heat removal capability of the open Blowdown l cooling heat exchangers and the ICW lube water or reduce output flow
- of the hypochlorite system.
F classification This safety evaluation involves an assessment of the affects on a i safety related system, and therefore, is classified as safety related. l
. 4.O F1TI.UEE MODES RED EFFECTS RE11.TSI$
1 l The proposed configuration is bounded by the failure modes and affects j analysis in the FSAR (as referenced above).
5.e EL&MT RESTRICTIQMS l This configuration may remain in effect until the next plant extended l
! shut down. The FSAR, plant drawings and other affected engineering
! documents will not be revised, due to the limited duration of the ;
- proposed valve alignment. ,
j l 6.0 EFFECT ON TECENICAL SPECITICATIoMS i
i Implementation of the proposed valve configuration for I-TCV-14-45
! does'not require changes to the Technical specifications. By clamping i the valve in an open throttle position, the valve is capable of j performing its intended safety function.
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JPN-PSL-SENP-94-021 *
! REVISION 1 l PAGE 8 OF 10 7.0 UEREYIEEED SAFETY OUESTIgg DETERMIMATIQM h In accordance with 10 CFR 50.59, the responses to the following i questions serve to determine whether the proposed configuration
{ constitutes an unreviewed safety question:
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! 7.1 Does the proposed activity increase the probability M occurrence j of an accident previously evaluated in the SAR?
I The probability of an accident occurring which will challenge the
{ valve's safety f acticn has not changed with the new configuration of
! valve I-TCV-14-48, the valve in the clamped position will increase the l availability cf flow to the CCW train. The clamp itself is designed
! to withstand a design basis seismic event. Therefore, the proposed I activity does not increase the probability t;f occurrence.of an 1 accident previously evaluated in the SAR.
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! 7.2 Does the proposed activity increase the consequences of an accident previously evaluated in the SAR? l l
f The proposed configuration does not adversely affect the safety i J function of the valve. one failure mode (ie, valve failure in the j closed position) has been removed. With the valve in its lamped 1 position, the consequences of providing one less train of cooling
! water is decreased. The clamp itself is designed to withstand a l design basis seismic event. Therefore, the proposed activity does not
! ine- the consequences of an accident previously evaluated in the l SAR.
l 7.3 Does the proposed activity increase the probability of an i occurrence of a malfunction of equipment important to safety j previously evaluated in the SAR7 l The proposed valve alignment does not change the valve u designed j safety function. The valve is required to be open to acuit flow
- through the CCW heat M anger. . The clamped throttle pcsition ensures j the valve would perform this function. The clamp itself is designed
- to Seismic category I requirements and therefore maintaints the position of the valve. The proposed activity does not increase the probability of an occurrence of a malfunction of equipment important to safety previously evaluated in the SAR.
i j 7.4 Does the proposed activity increate the consequences of a
! malfunction of equipment important to safety previously evaluated j
in the SAR?
} The proposed valve alignment does not affect the CCW system operation, j performance or safety function, nor does the new condition affect the i operation, performance or safety function of the intake cooling water j system. Equipment and systems important to safety will function in
! the same man..er in the new condition. The consequences of a
! malfunction ir. the new condition are equal to those of the previous I condition. Therefore, the proposed activity does not increase the j consequences of a malfunction of equipment important to safety
, previously evaluated in the SAR.
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' JPW-PSL-SENF-94-031 1
/ REVISION 1 l I
PAGE 9 OF 10 4
7.5 Does the proposed activity create the possibility of an accident of a different type than any previously evaluated in the SAR?
p New accident initiators are not introduced through this configuration. ,
Therefore, the proposed activity does not create the possibility of an socident of a different type than any previously evaluated in the SAR.
/ 7.6 Does the proposed activity create the possibiliti of a
} malfunction of equipment important to safety of a different type l j
i h than any previously evaluated in the SAR?
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! New accident initiators are not introduced through the proposed valve Failure of the valve is currently considered in the FSAR, I -
alignment.
the clamp design reduces the probability of failure as describedthis Therefore, in H is alignment is bounded by the FSAR.
O .V.the FSAR.estivity does not create the possibility of a malfunction of equipment j to safety of a different type than any previously evaluated
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the SAR. ~ l l
Tj Does the sc-;-::M activity reduce the margin of safety as defined !
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" in the basis for any Tan-hnical specification?
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73 reposed activity does not change assumptions H erefore,used as the basis the proposed et the Technical specifications.
l does not reduce the margin of safety as defined in the basis
, technical specification.
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N :::' configuration does not affect safe operation of the t
l cooling Water System and the Component Cooling Natar system. In i
,2 the y.,ct:rd configuration does not constitute an unreviewed i
r and does not require a change to the Technical
. Therefore, implementation of tho' proposed does not require prior NRC approval.
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, the valve in its clariped position, does not s,
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! safety or impact the plant Maical specifications j
acceptable. Bowever, due to the reduction in cooling
'the non-safety related portions of the ICW system, the
' precautionary measures are recommended below:
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. y 6 2ncreased monitoring of turbine-generator operating tamparatures. Procedural and manufacturer's guidelines l
', abeeld not be exceeded.
- A" ICW j ~
"A" train maintenance activities to ansure
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monitoring of the other systems supplied by the
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1 operators are aware of the reduction in response tiau i le for taking compensatory measvres.
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- JPN-PSL-CENP-94-021
,i REVISION 1 PAGE 9 OF 10 I
7.5 Does the proposed activity create the possibility of an accident l
of a different type than any previously evaluated in the SAR?
j 7 New accident initiators are not introduced through this configuration.
l Therefore, the proposed activity does not create the possibility of an accident of a different type than any previously evaluated in the SAR.
7.6 Does the proposed activity create the possibiliti of a g( malfunction of equipeant important to safety of a different type than any previously evaluated in the SAR7 1
! - New accident initiators are not introduced through the proposed valve I alignment. Failure of the valve is currently considered in the FSAR, the clamp design reduces the probability of failure asTherefore, describedthis in 6 .the FSAR. This alignment is bounded by the FSAR.
i i Vestivity does not create the possibility of a malfunction of equipment to, safety of a different type than any previously evaluated
'ia the SAR.
i Does the w wyssed activity reduce the margin of safety as defined
<-' in the basis for any Technical Specification?
' i W activity does not change assumptions used Therefore, theasproposed the basis et the Technical Specifications.
! does not reduce the margin of safety as defined in the basis
. technical specification.
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configuration docs not affect safe operation of the l $llepling Water System and the Component Cooling Water systaa. In
, the yis?-: M configuration does not constitute an unreviewed l and does not require a change to the Technical
. Therefore, implementation of the proposed does not require prior NRC approval.
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, the valve in its clasped position, does not safety or impact the plant tenical specifications j acceptable. However, due to the reduction in coollag 4
.teithe non-safety related portions of the Icw system, the l
' ' precautionary measures are recossended below:
l[w h- =-M monitoring of turbine-generator operating temperatures. Procedural and manufacturer's guidelines
- ~ should not be exceeded.
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! ~t "A" train maintenance activities to ensure ility.
{ w i " monitoring of the other systems supplied by the l
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' operators are aware of the reduction in response tis j
le for taking cospensatory measures.
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' ., rm-ree w . -v.. i REVISION 1 l PAGE 10 0F 10 *l
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! s.e murmamunna i
1, 1. St. Lucie Unit 2 Technical Specifications, Amendment No. 66
- 2. St. Lucie Unit 2 FSAR, through Amendment No, a i
! 3. St. Lucia Unit 2 SER, NUREG-0843
- 5. St. Lucie Unit 2 Intake Cooling Water System Design Basis Document, No. DoD-ICW-2, Revision 0 l
l 6. Calculatior. PSL-2FJN-93-017, Rev. 1, " Intake Cooling Water (ICN)
! System Perfor'unce" ,
i 7. Calculation PSL-5FJN-92-001, Rsv. O, " Interim operability of the
! CCN Systems"
! s. Calculation PSL-2FJN-92-055, Rev. O, " Interim operability of i Degraded ICN Pumps" 1
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