ML17227A315
| ML17227A315 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/25/1992 |
| From: | Sager D FLORIDA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| L-92-38, TAC-M81282, NUDOCS 9203020264 | |
| Download: ML17227A315 (13) | |
Text
ACCELERATED DIS'HUBUTION DEMONSTT&TION SYSTEM REGULAT INFORNATZON DISTRIBUTIONISTEN (RIDE)
AGCESSION NBR:9203020264 DOC.DATE: 92/02/25 NOTARIZED:
NO FACIE:5C-389 St. Lucie Plant, Unit 2, Florida Power a Light Co.
AUT$.NAME AUTHOR AFFILIATION SAGER,D.A.
Florida Power a Light Co.
REC'IP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
DOCKET 05000389
SUBJECT:
Forwards revised inservice testing program relief requests re testing of HPSI pump s installation of flow element in LPSI
& auxiliary feedwater sys,per NRC 911205 ltr denying util relief requests re flow measurements of pumps.
DISTRIBUTION CODE:
A047D COPIES RECEIVED:LTR I
ENCL L SIZE:
TITLE: OR Submittal: Inservice Inspection/Testing/Relief from ASME Code NOTES:
RECIPIENT ID CODE/NAME PD2-2 LA NORRIS,J INTERNAL: ACRS NRR/DET/EMEB 7E OC/gFMB~
@GaFILZ 01 RES/DSIR/EIB" EXTERNAL: EGGG BROWNFB NRC PDR COPIES LTTR ENCL 1
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1 RECIPIENT ID CODE/NAME PD2-2 PD NRR/DET/ECMB 9H NUDOCS-ABSTRACT OGC/HDS3 RES MILLIMAN,G EG&G RANSOME,C NSIC COPIES LTTR ENCL 1
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1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAMEFROM DISTRIBUTION LIS13 FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 22 ENCL 19
P.O. Bex 12S, Ft Pierce, FL 34954-0128 February 25, 1992 L-92-38 10 CFR 50.4 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555 Gentlemen:
RE:
St. Lucie Unit 2 Docket No. 50-389 NRC TAC No.
M81282 In-Service-Testin IST Pro ram Relief Re uest On December 5,
- 1991, the NRC denied a Florida Power and Light Company (FPL) relief request for not measuring flow for the various pumps.
In addition, the letter requested FPL to provide a proposed test method and implementation schedule for complying with the requirements to measure flow for the various pumps which currently have no flow instrumentation.
The response was required within 90 days of the date of the NRC letter.
Attached please find the FPL response to the Safety Evaluation Report.
The response includes the schedule for implementation of the additional testing.
The resolution meets the guidelines of Generic Letter 89-04, Position 9.
Please contact us if there are any questions about this submittal.
Very truly yours,
~p ~~'g Vice President St. Lucie Plant DAS/GRM/kw
,cc:
Stewart D. Ebneter, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant DAS/PSL 8623-92 9203020264 920225 PDR ADOCK 05000389 P
/fg
1 1
l I
St. Lucie Unit 2 Docket No. 50-389 NRC TAC No. M81282 In-Service-Testin IST Pro ram Relief Re uest ATTACHMENT HIGH PRESSURE SAFETY INJECTION HPSI NRC Recommended Action:
A.
Quarterly testing of each HPSI
- pump, using the installed suction and/or minimum flow line surface mounted flow elements.
B.
Mode 6 full flow testing of each HPSI pump (which is not only needed to demonstrate pump capability, but forward flow stroking of various check valves as well).
FPL Res onse:
The 2A and 2B HPSI Pumps are tested quarterly using the mini-flow recirculation lines.
Differential pump head and vibration are measured.
During refueling outages, the HPSI Pumps are flow tested by discharging into the refueling cavity while in Mode 6.
Differential pump head, pump flow, and vibration are measured.
The suction, discharge, and header check valves are full flow tested as part of the Mode 6 testing.
The Mode 6 testing was first performed on Unit 2 during the 1990 refueling outage in response to the Generic Letter 89-04. Allthe tests were completed satisfactorily.
The installation of a flow instrument in line 6-CS-500 is not warranted nor is it required.
The present type and frequency of the HPSI Pump tests are consistent with the recommendations of Generic Letter 89-04.
NRC Recommended Action:
C.
Addition of check valves V3102 and V3103 to the ISI program.
FPL Res onse:
The HPSI Pump mini-flow recirculation valves, V-3102 and V-3103, were not included in the last Unit 2
Pump and Valve Program submittal but they have been included in the latest revision.
Partial flow tests of these valves have been included in the Unit 2 valve test procedures since November 2,
1985 when Rev-0 of Administrative Procedure (AP) 2-0010125A, Surveillance Data Sheets, was approved.
In 1991, the Unit 2 valve test procedures were updated to add back flow tests during cold shutdown and disassembly during refueling outages.
4 p
LOW PRESSURE SAFETY INJECTION LPSI NRC Recommended Action:
A.
Installation of a flow element in line 6-CS-500 for full flow testing B.
Testing each LPSI pump quarterly at full flow.
FPL Res onse:
LPSI Pump flow through line 6-CS-500 is possible but the line is not instrumented to measure flow.
The installation of a flow instrument in line 6-CS-500 is not warranted nor is it required.
The present type and frequency of the LPSI Pump tests are consistent with the recommendations of Generic Letter 89-04.
The 2A and 2B LPSI Pumps are tested quarterly using the mini-flow recirculation lines.
Differential pump head and vibration are measured.
During cold shutdown, the LPSI Pumps are substantial flow tested when the pumps are used for residual heat removal.
Differential pump head, pump flow, and vibration are measured.
The discharge and header check valves are full flow tested as part of the cold shutdown tests.
The LPSI pump suction valves are full flow tested by taking suction from the Refueling Water Tank (RWT) and discharging into the refueling cavity during Mode 6.
The cold shutdown and Mode 6 testing were first performed on Unit 2 during the 1990 refueling outage in response to the Generic Letter 89-04.
All the tests were completed satisfactorily.
NRC Recommended Action:
C.
Simultaneous with each full flow test under B above, monitor flow through the mini-flow path (to demonstrate pump protection and check valve stroking).
D.
Further review of the design adequacy of the minimum flow line (although not specifically ISI related).
E.
Addition of check valves V3105 and V3104 to the ISI program.
FPL Res onse:
On August 6 10, 1990, the NRC performed an unannounced inspection on the NRC Bulletin 88-04, Potential for Safety-Related Pump loss.
The results of this inspection are in the NRC Inspection Report 335/389 90-19 dated August 23, 1990.
The following documents were used to verify the St. Lucie response to NRC Bulletin 88-04:
1.
FPL Purchase Order (PO) gB88636-90081 and Sulzer-Bingham letter dated October 25,1988 for the HPSI Pumps;
~
2 ~
3 ~
4 ~
PO gB88636-90080 and Ingersoll-Rand letter dated October 18,1988 for Unit 2 AFW and CS, and Units 1
& 2 LPSI Pumps; PO gB88633-90084 and Byron-Jackson letter dated September 22, 1988 for Unit 1 AFW and CS Pumps; Goulds letter dated July 25, 1988 for the BAM Pumps.
These documents together with system design drawings established that the installed mini-flow line capacities are greater than or equal to the latest manufacturers'ecommendations for all pumps except for the Unit 1 CS Pumps (50 gpm installed verses 150 gpm recommended).
FPL Calculation No. PSL-0-J-M-90-0019 established the adequacy of a 50 gpm mini-flow for Unit 1 CS pumps.
- Finally, these pumps have been in use for over 15 years for Unit 1 and over 8 years for Unit 2.
There has not been any pump degradation attributed to insufficient mini-flow recirculation flow.
The LPSI Pump mini-flow recirculation valves, V-3104 and V-3105, were not included in the last Unit 2
Pump and Valve Program submittal but they have been included in the latest revision.
Partial flow tests of these valves have been included in the Unit 2 valve test procedures since November 2,
1985 when Rev-0 of AP 2-0010125A, Surveillance Data Sheets, was approved.
In 1991, the Unit 2 valve test procedures were updated to add back flow tests during cold shutdown and disassembly during refueling outages.
AUXILIARYFEEDMATER AFW NRC Recommended Action:
A.
Installation of a flow element in the common mini-flow line.
D.
Addition of check valves
- V9303, V9304, and V9305 to the ISI program.
FPL Res onse:
The AFW Pump mini-flowrecirculation valves, V-09303, V-09304, and V-09305, were not included in the last Unit 2
Pump and Valve Program submittal but they have been included in the latest revision.
Partial flow tests of these valves have been included in the Unit 2 valve test procedures since November 2, 1985 when Rev-0 of AP 2-0010125A, Surveillance Data Sheets, was approved.
In 1991, the Unit 2 valve test procedures were updated to add partial flow tests during the quarterly tests and disassembly during refueling outages.
Back flow testing is not required since the flow through the mini-flow recirculation lines are limited by flow orifices.
The amount of flow through an idle pump is considered to be negligible.
This testing is consistent with the recommendations of
Generic Letter 89-04, therefore no further testing or flow instruments are required.
NRC Recommended Action:
B.
Performance of monthly tests in recirculation (NRC requires monthly, versus quarterly, tests for AFW pumps).
C.
Full flow testing at each cold shutdown (Mode 5).
Note that the turbine driven pump would have to be tested in Mode 3 or 4 (hot standby or hot shutdown).
FPL Res onse:
The 2A, 2B, and 2C AFW Pumps are tested monthly, as required by the Technical Specifications, using the mini-flowrecirculation lines.
Differential pump head and vibration are measured.
During cold shutdown, the 2C AFW Pump is tested while in Mode 3 and the 2A and 2B are flow tested during Modes 3,
4, or 5.
Differential pump
- head, pump flow, and vibration are measured.
The suction and discharge check valves are full flow tested as part of the cold shutdown tests.
The cold shutdown testing was first performed on Unit 2 during the 1990 refueling outage in response to the Generic Letter 89-04.
All of the tests were completed satisfactorily.
NRC Recommended Action:
E.
Include verification of reverse flow closure (can probably best be performed by periodic disassembly and inspection) for AFW turbine steam supply valves V-8130 and V-8163 in the ISI program testing.
FPL Res onse:
The flow exercising of the steam admission
- valves, V-8130 and V 8163( have been included in earlier revisions of the Unit 2 Test Program.
The latest revision includes partial flow testing and valve disassembly during each refueling outage.
Both valves were inspected during the 1990 Unit 2 refueling outage.
BORIC ACID MAKE-UP BAM NRC Recommended Action:
A.
Testing of each BA pump quarterly, using existing or test level instrumentation on the BA tanks to determine flow by transferring boric acid from one tank to another.
FPL Res onse:
Contrary to the ORNL TER, quarterly or cold shutdown flow testing of the BAM Pumps is not practical.
There are three flowpaths available for flow testing the BAM Pumps.
These include the primary flowpath into the charging pump suction
- header, a
recirculation line leading back to the RWT or the Volume Control Tank (VCT), and the mini-flowrecirculation line which returns back to the BAM Tanks.
None of these flowpaths are totally satisfactory for quarterly or cold shutdown testing for the following reasons:
Operating the BAM Pumps discharging into the charging pump suction header requires the introduction of highly concentrated boric acid solution from the BAM Tanks to the suction of the charging pumps.
This, in turn, would result in the addition of excess boron into the RCS.
This rapid insertion of negative reactivity would result in a rapid RCS cooldown and depressurization.
A large enough boron addition would result in an unscheduled plant trip and a possible initiation of Safety Injection Systems.
During cold shutdown, the introduction of excess quantities of boric acid into the RCS is undesirable from the aspect of maintaining proper plant chemistry and the inherent difficulties that may be encountered during the subsequent startup due to over-boration of the RCS.
The waste management system would be overburdened by the large amounts of RCS coolant that would require processing to decrease its boron concentration prior to startup.
This flowpath is used to perform flow testing of the BAM Pumps during refueling outages.
After the reactor has been shutdown and all control rods have been
The BAM Pumps are flow tested by having each pump supply boric acid to two running charging pumps.
The check valve in the gravity feed line (V-2190),
the two check valves in the emergency boration flowpath (V-2177 and V-2526), the BAM Pump discharge check valves (V-2443 and V-2444),
and the check valve in the flowpath from the RWT to the charging pumps are also flow tested at this time.
These tests were completed satisfactorily during the Unit 2 1990 refueling outage.
2.
The second circuit recirculates water to the RWT or the VCT.
During normal plant operation at power it is undesirable to pump to the RWT and deplete the BAM Tank inventory.
One of the two BAM Tanks is maintained at Technical Specification level while the other is used as required for plant operation.
The Technical Specification BAM Tank can not be pumped from because it must be maintained at a level near the top of the tank.
The other BAM Tank level can vary from test to test by as much as 15 to 20 feet, depending upon its recent use.
This
variance in pump suction pressure would have a direct affect on pump head and flow such that test repeatability would be questionable.
In addition, the tanks level instrument range is 0
100 4
(99 gallons/4) and has an accuracy of + 0.5 4.
Performing the flow test described in the ORNL TER, 142 gpm.
for 10 minutes, would result in an expected flow accuracy of
+10.4 gpm (+7.3%).
To approach the acceptable limits required by the ASME Section XI Code, the flow test would have to last at least 50 minutes and pump over 7,100 gallons.
This test is not practical.
(Note:
Using measuring tape to determine tank
- height, as described in the Diesel Oil Transfer section, is not practical when the fluid to be measured is acidic and contaminated.)
3.
The third test method involves pumping from one BAM Tank to the other.
This can be accomplished by either cross tying the pump suction or their discharge lines.
Cross tying the pump suction would require one of the tanks to be isolated, taking it and its contents out of service.
This is unacceptable.
The other method routes flow from down stream of the boric acid strainer back to one of the BAM Tanks.
The flowpath is a fixed resistance circuit consisting of one and two inch piping without any flow measuring instrumentation installed.
Pumping boric acid from tank to tank would be possible but the flowrate would be relatively small.
This would limit the pump operation to the low flow section of the pump curve.
As stated in the ORNL
- TER, "substantial degradation in pump performance can occur at high flow rates with no observable change in the low-flow end of the curve".
Therefore, this low flow path could fail to identify pump performance degradation.
This flowpath is also subject to the same flow errors described in paragraph g2 above.
This flow path would not allow an acceptable flow test either.
NRC Recommended Action:
B.
A more thorough review of the ISI testing in this system.
(This would require test procedure review and direct discussions with St. Lucie personnel.)
FPL Res onse:
A review of the Chemical Volume Control System has already been performed.
As a result of these
- reviews, the Unit 2 test procedures has been updated to reflect the testing recommendations of the NRC Generic Letter 89-04.
Recirculation valves V-2650 and V-2651 were listed in the first revision of the Unit 2
Pump and Valve Program and have not been removed from the program nor from the test procedures.
They are fast acting valves
(<2sec.)
and are tested quarterly in the closed direction.
The valve FCV-2210Y is exercised closed each quarter.
The BAM Pump discharge check valves
are partial flow tested by making up to the VCT with flow verified by FRC-2210Y.
Containment S ra CS NRC Recommended Action:
A.
Quarterly, full flow testing through the full flow path discussed under LPSI.
FPL Res onse:
The 2A and 2B CS Pumps are tested quarterly using the mini-flow recirculation lines.
Differential pump head and vibration are measured.
During refueling outages, the CS Pumps are flow tested by taking suction from the RWT and discharging into the refueling cavity through the shutdown cooling lineup while in Mode 6.
Differential pump head, pump flow, and vibration are measured.
The suction and discharge valves are full flow tested as part of the Mode 6 testing.
The Mode 6 testing was first performed on Unit 2 during the 1990 refueling outage in response to the Generic Letter 89-04.
All of the tests were completed satisfactorily.
CS Pumps flow through line 6-CS-500 is possible but the line is not instrumented to measure flow.
The installation of a
flow instrument in line 6-CS-500 is not warranted nor is it required.
The present type and frequency of the CS Pump tests are consistent with the recommendations of Generic Letter 89-04.
Diesel Fuel Oil Transfer DOT NRC Recommended Action:
A.
Performance of a quarterly test of each DOT pump through a
selected path in which flow is measured (multiple potential paths available).
FPL Res onse:
The Unit 2 DOT pumps have been under investigation since January 1990 to determine the feasibility of performing flow tests.
The flow test measures the amount of diesel fuel oil transferred from one Diesel Fuel Oil Storage Tank (DOST) to the other.
Initially, the installed DOST level instruments were used by the test.
Flowrate errors of +20 gpm. were encountered.
Portable ultrasonic flow meters were also tested during the initial DOT flow tests.
The flow values indicated by the meter also varied on the order of
+ 10 gpm.
The tests were repeated again, but this time the Diesel Oil Storage Tank levels were measured by dipping a tape measure into the tank.
The calculated flow errors dropped by an order of
t
m'agnitude.
The latest revision of Unit 2 Pump and Valve Program includes a brief description of the new quarterly flow test and an explanation of the revised test limits.
NRC Recommended Action:
B.
Inclusion of check valves and solenoid valves between the DOT pumps and the day tanks in the ISI program.
C.
Require monitoring of suction pressure downstream of the suction strainer.
FPL Res onse:
There are not any suction strainers in the DOT system.
The piping from the DOST to the suction of the DOT Pumps is three inches in diameter and is under 10 feet in length.
There should not be any significant head loss experienced in this piping during the flow tests.
Therefore, using the DOST level for pump suction pressure is a good approximation.
The latest Unit 2 Pump and Valve Program has included the DOT pump discharge reliefs (SR-17221 and SR-17222) and the DOT pump discharge check valves (V-17204 and V-17214).
The day tank fillvalves have also been added to the program.
The day tank fillvalves and the DOT pump discharge check valves were not listed in the first revision of the Unit 2 Pump and Valve program, but have been tested by the AP 2-0010125A,Surveillance Data Sheets, since Rev-0 was approved on November 2, 1985.
Like many other plant systems, the Unit 2 DOT Pumps have discharge relief valves installed in the system.
These other systems are considered to have a "fixed resistance path" in their testing procedures, therefore the DOT pumps should also be considered fixed.
The DOT pumps have a shut off head of approximately 80 ft.
or 38.4 psig.
The discharge reliefs, SR-17221 and SR-17222, do not lift until 100 psig.
Since the DOT Pumps could never lift the reliefs on their own, the discharge piping should be considered a
"fixed resistance path" contrary to what is stated in the ORNL TER.