ML20214N320
| ML20214N320 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 09/08/1986 |
| From: | Johnson I COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-86-002, IEB-86-2, NUDOCS 8609160239 | |
| Download: ML20214N320 (22) | |
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[ One First Nabonai Plaza. CNcago, IEnoisAddress Reply to: Post Omco bow N/ Chca00, IEnos 80600 0767 i
September 8, 1986 Mr. James G. Keppler Regional Administrator U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL. 60137
Subject:
LaSalle County Station Units 1 and 2 NRC Docket No. 50-454 & 50-455 Supplemental Response to NRC
Reference:
(a) I.E. Bulletin 86-02, J.M. Taylor to all OLS and CPS, dated July 18, 1986 (b) Letter from I.M. Johnson to J.G. Keppler, dated July 25, 1986 and Attachments (c) Letter from I.M. Johnson to J.G. Keppler, dated August 29, 1986
Dear Mr. Keppler:
In our July 25, 1986 response to IE Bulletin 86-02, it was indicated that information specific to LaSalle County Station Unit 1 4 would be submitted upon completion of the Unit 1 test program. That information was provided in an August 29, 1986 letter (Reference (C)).
In addition, in a conference call with the NRR staff on September 5, 1986, Commonwealth Edison was requested to update that response to summarize testing performed on the SOR series 102 and 203 differential pressure switches, describe corrective actions that will be taken prior to startup, and additional testing and augmented surveillances that will be performed during and after startup to verify proper operation of the switches and associated systems on i both units 1 and 2. This revised response is provided in Attachment l
1 to the letter.
l 8609160239 860908 i
d PDR ADOCK 05000454 PDR fg Ilf G i i
l To the best of my knowledge and belief, the statements contained in Attachment I are true and correct. In some respect, these statements are not based on my personal knowledge but upon information furnished by other Commonwealth Edison employees, contractor employees, and consultants. Such information has been reviewed in accordance with company practice, and I believe it to be reliable.
Please address any questions that you or your staff may have concerning our supplemental response to this office.
One signed original with attachments is being sent directly to the U.S. Nuclear Regulatory Commission Control Room in Washington for reproduction and distribution as requested in the bulletin.
Respectfully, I ~
I. M. Johnson
, Nuclear Licensing Administrator
/klj cc: U.S. NRC Document Control Desk /'
Washington, DC. 20555 Resident Inspector-LaSalle SUBSCRBEDandQWgRNto day of if 6med,thip It.
befor et h, f' , 1986 hl daA _
~~ ~ Notary Public I" 2076K
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ATTACHMENT 1 I REVISED LASALLE COUNTY STATION, UNITS 1 AND 2 SUPPLEMENTAL RESPONSE TO IE BULLRTIN NO. 86-02 STATIC-O-RING DIFFERENTI AI.
PRESSURE SWITCHES. SEPTEMBER 1986 4
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LASALLE COUNTY STATION, UNITS 1 AND 2 RESPONSE TO IE BULLETIN No. 86-02 STATIC-O-RING DIFFERENTIAL PRESSURE SWITCHES
- 1. SOR DIFFERENTIAL PRESSURE SWITCHES INSTALLED AT LASALLE Som series 102 and 103 differential pressure (DP) switches are installed on both units at LaSalle. During the spring 1985 outage on Unit 2, 59 SOR DP switches were installed as part of an environmental qualification modification to replace the original switches. On Unit 1, 58 SOR DP switches were installed during the first quarter of 1985 and during the first refueling cutage in the first two quarters of 1986.
These switches are used in the following applications:
No. of Switches Unit 1 Unit 2 Application 22 23 Reactor Water Level 1,2,3, and 8 8 8 BCCS Minimum Flow 16 16 Main Steam Line High Flow Isolation 8 8 RCIC/RHR High Steam Line Flow Isolation 4 4 RHR Shutdown Cooling Line High Flow Isolation Table 1 contains a complete list of the series 102 and 103 SOR DP switches l installed on both Units at LaSalle in both safety and non-safety related I applications.
- 2. Operator Training All licensed shift personnel have been trained on the June 1 event at LaSalle Unit 2 with regards to the SOR DP switches. This training included a discussion of where the switches are installed, their functions, and their setpoints. The " Conduct of Operations" requirement to monitor plant instrumentation and initiate manual action if a nominal Tech. Spec. setpoint is exceeded and the required automatic action does not occur was also re-emphasized.
- 3. Special Testino of SOR DP Switches LaSalle has performed special testing on the Unit 1 and 2 switches to characterize the setpoint variability. These setpoint characterization tests measured the shift in setpoints due to the increase in static pressure from calibration to operation, the effects of cycling the switch during calibration, and the repeatability of the switches.
The setpoint characterization program consists of a static pressure cycling test and a 24-hour static pressure test. This testing program is described in detail in Reference 2.
DOCUMENT ID 41181
On Unit 2, the etctic prcx uro cycling tect was perfstmed on c11 switches except for a few BCCS minimum flow switches. The performance of these switches i.es verified during ECCS system operation. On Unit 1, the static pressure cycling test was performed on all switches.
! For Unit 2 the 24-hour static pressure test was performed on a representative sample (more than half) of switches, whereas on Unit 1 every switch (except a few BCCS minimum flow switches) was tested. l Switches in every application were tested. The size of the Unit 2 sample was based on a comparison of the amount of existing margin between the r i
desired setpoint and Tech. Spec. limit to the adjustable range of the switch. In applications where the existing margin was very small with respect to the adjustable range of the switch (reactor water level 3, i i reactor water level 8, and main steam line high flow switches), every switch in the Unit 2 (and Unit 1) application underwent the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> static pressure test.
i From the early test results on Unit 2, it was observed that the switches with the largest repeatability error also exhibited the largest static '
shift error. Unit 2 switches with the largest repeatability errors were then selected to be tested at static pressure over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Therefore, the test results on this sample bounded all of the switches for that l application, and performance of the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> static pressure test on all Unit 2 switches was not necessary for determining new setpoints for that application. Table 2 provides the sample size tested in each switch application.
As stated above, the test program on Unit I was more comprehensive in that in every application except the BCCS minimum flow valves, 100% of the switches underwent both repeatability (static pressure cycling) and static
! offset (time-pressure " soak") testing. Five of the eight BCCS minimum flow valve switches were not tested for static offset because the switch i setpoint chosen allowed much more margin than the static offset measured l
! from the three identical switches tested required, i A series of static pressure tests conducted over various time intervals up 4 to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> demonstrated that 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was sufficient to observe the full static pressure shift in the setpoint. In these series of tests, four l
j switches were tested at static pressures longer than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and their 2
setpoints changed very little after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. References 2 and 3 contain this test data. This time period has also been verified by a long-term 1 testing program at SON on model 103AS-B212 DP switches. Their test data shows that the switch setpoints shift by 0.6 inches W.C. or less between 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and 2 weeks. This data is contained in reference 4.
- The setpoint variance for all Son switches has been fully characterized l prior to resuming operation. Because of this program and the augmented surveillance program described in Table 4, additional special tests are not anticipated. ,
1 DOCUMENT ID 41181 1
- 4. Test Results/ Failures <
All of the testing has been completed on both Unit 1 and Unit 2 switches.
- The test results are summarized in Table 2. These test results show that some of the SOR DP switches would not have met their Tech. Spec.
requirements under normal operating conditions at their existing setpoints. However, based on a GB analysis, all of the switches except for one switch on Unit 2 would have tripped within analytical limits (see Reference 2).
I 1 Per reference 1 LaSalle station has submitted a report (LER 86-011-00) in accordance with 10 CFR 50.*73 which addresses the June 1, 1986, event on Unit 2. A supplemental report for Unit 2 was submitted, (Reference 2) on completion of the testing. On Unit 1, a final report was submitted as j shown in Reference 6. ;
i i 5. Interim Perfor-race Monitorine Procram
. Since corrective actions will be taken prior to unit startup, an interim performance monitoring program was not developed. The corrective actions that will be taken are described in the next section. Note that when 100%
) of the dp switches on Unit I were tested, it was found that for some applications the worst case static offset and repeatabilities were found
- to be smaller than allowed for in the determination of the Unit 2 l setpoints. The initial settings for the Unit 1 switches use the Unit 2 values with the exception of the setpoint for Main Steam Line High Flow
' switches. In the future these setpoint values may be changed to take
- advantage of the more complete test data.
- 6. Description of Corrective Actions on the basis of the setpoint characterization tests, the setpoints of the differential pressure switches will be revised prior to startup to provide
- additional margin for static pressure shift and repeatability. The 1
revised setpoints and margins are listed in Table 3. These revisions will insure that the SOR DP switches will meet their Technical Specification 4 requirements. Switches that do not meet the static shift and i repeatability acceptance limits given in Table 3 will be replaced. New j switches will be tested to verify that they meet these limits.
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- To provide additional assurances that the switches will function properly, j the accs minimum flow switches have been tested at their new setpoints i during system operation, and reactor water level drop tests have been performed on Unit 2 at pressures of 0.0, 950, and 500 psig to verify the
! level 3 switch setpoints. These level drop tests were performed during startup of Unit 2 following the recently completed outage and the 950 psig i test will also be conducted during shutdown for the next refueling
- outage. On Unit 1, a 0.0 psig level drop test will be conducted to verify system operability prior to start-up and a 950 psig level drop test will l
be performed at shutdown for the second refueling outage. When plant j conditions permit, a level drop test will be performed at approximately
- 950 psig during the first planned shutdown greater than 3 months after
{ start-up. The calibration procedures will also be revised to require the
- instrument maintenance technician to record the first actuation as the I "as-found" and to eliminate the effects of cycling. Instead of cycling i
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DocuMNNT ID 41181
. the switch between its trip and rcset points, all actuations will be obtcined by cycling from oither z:ro cr full-scolo DP to cimulcto actual operating conditions. The procedures will also contain " action" and
" rejection" limits. If a switch setpoint exceeds its action but not its rejection limit, its surveillance frequency will be adjusted as described in table 4. If its setpoint exceeds the rejection limit or the action limit on two consecutive surveillances, the switch will be replaced as described in Table 4.
After startup, a quarterly surveillance frequency will be established on these switches. In addition, the Unit 1 and Unit 2 level 3 switches will be calibrated at 2 weeks, 4 weeks, 2 months, and 4 months before they are put on a quarterly cycles.
A complete description of the corrective actions that will be taken can be found in Table 4 and in Reference 5.
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l DOCUMENT 1D 41181
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REFERENCES
- 1. July 1, 1986, letter from C. Reed to J. G. Keppler transmitting LER 86-011-00.
- 2. August 8, 1986, letter from C.M. Allen to H. R. Denton transmitting the
" Report of Investigation of Static-O- Ring Dif ferential Pressue Switches".
- 3. July 21, 1986 letter from M.S. Turbak to H. R. Denton regarding the validity of 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> static pressure tests.
- 4. July 23, 1986, letter from M.S. Turbak to H. R. Denton transmitting daily and two week test data.
- 5. July 24, 1986, letter from M. S. Turbak to H. R. Denton transmitting the Unit 2 Executive Summary.
- 6. September 5, 1986, letter from C. M. Allen to H. R. Denton transmitting the Unit 1 Executive Summary.
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i DOCUMENT ID 41181
TABLE 1 LIST OF INSTALLED SOR DP SWITCHES
< SWITCH l NUMBER USE SETPOINT MODEL RANGE j B21-N024A.B.C.D LOW REACTOR 2 +12.5" RWL
{ WATER LEVEL (s 63.78" W.C.
j 3-LOW LEVEL increasing) 103AS-B212-NX-CIA-JJTTX6 7-100 in. W.C.
j SCRAM AND PCIS GROUPS 6 AND 7 I C21-N026AB BB REACTOR WATER 1 -50" RWL CB.DB LEVEL -2 PCIS (s 145.6" W.C. 103AS-BB203-NX-CIA-JJTTX6 20-200 in. W.C.
GROUPS 1 THRU S increasing) l
- C21-NO31A.B.C.D REACTOR WATER 2 -50" RWL i LEVEL 2 - (s 145.6" W.C. 103AS-B203-NX-CIA-JJTTX6 20-200 in. W.C.
HPCS INITIATION increasing l
i B21-NO37AB.BB REACTOR WATER LEVEL 1 -50" RWL f CB.DB RCIC INITIATION (s 145.6" W.C. 103AS-B203-NX-CIA-JJTTX6 20-200 in. W.C.
increasing) 103AS-BB205-NX-CIA-JJTTX6 40-300 in. W.C.
C21-NO37AA.BA REACTOR WATER LEVEL 1 -129" RWL
, CA.DA 1-ECCS INITIATION ($ 202.2" W.C.
Increasing) i
- C21-NO38A.B REACTOR WATER 2 +12.5" RWL j LEVEL 3- (s 63.78" W.C. 103AS-B212-NX-CIA-JJTTX6 7-100 in. W.C.
ADS PERMISSIVE increasing) l i i
DOCUMENT ID 41181
i TABLE 1
! LIST OF INSTALLED SOR DP SWITCHES SWITCH NUMBER USE SETPOINT MODSL RANGE 2E12-N010AA OPENS RHR A MIN FLOW 2 1000 spa J BYPASS VALVE ON LOW (2 5.9" W.C.
FLOW decreasing) l AB ALARM SWITCH 2 1500 gpm 103AS-B202-NX-CIA-JJTTX7 5-35 in W.C.
(2 13.3" W.C.
decreasing)
BA OPENS RHR B MIN FLOW 2 1000 gpm BYPASS VALVE ON LOW (2 5.9" W.C.
FIE W decreasing)
BB ALARM SWITCH 2 1500 gpm i
(2 13.3" W.C.
decreasing) j CA OPENS RHR C MIN FLOW 2 1000 gpm
- BYPASS VALVE ON I4W (2 5.9" W.C.
1 FLOW decreasing)
CB ALARM SWITCH 2 1500 gpm (2 13.3" W.C.
! decreasing) i l E21-N004 OPENS LPCS MINIMUM 2 750 gpm 103AS-B202-NX-CIA-JJTTX7 5-35 in. W.C.
FLOW BYPASS VALVE ON ( 2 4.38" W.C.
j LOW FLOW decreasing) l
- E22-N006 OPENS HPCS MIN FLOW 2 1000 gpm 103AS-B202-NX-CIA-JJTTX7 5-35 in. W.C.
BYPASS VALVE CN LOW (2 9.7" W.C.
, FLOW decreasing) s B21-N101B RX LEVEL 8-RCIC TRIP s 55.5" RWL 103AS-B212-NX-CIA-JJTTX6 7-100 in. W.C.
! (Unit. 2 only) (2 33.5" W.C.
! decreasing)
E31-N007AA AB RCIC/RHR HIGH STEAM s 123" W.C. 103AS-B203-NX-ClA-JJTTX7 20-200 in. W.C.
LINE FLOW ISOLATION increasisig E31-N007BA,BB RCIC/RHR HIGH STEAM s 87" W.C. 103AS-B203-NX-CIA-JJTTX7 20-200 in. W.C.
LINE FLOW ISOLATION increasing l
DOCUMENT ID 41181
TABLE I LIST OF INSTALLED SOR DP SWITCHES SWITCH NUISER USE SETpOINT MODEL RANGE E31-N008A.B.C.D MAIN STEAM LINE $ 111 psid 102AS-8305-NX-CIA-JJTTX6 100-500 psid HIGH FLOW ISOLATION incredsing E31-N009A.B.C.D MAIN STEAM LINE . $ 111 psid 102AS-B305-NX-CIA-JJTTX6 100-500 psid HIGH FLOW ISOEATION increasing E31-N010A.B.C.D MAIN STEAM LINE $ 111 psid 102AS-B305-NX-CIA-JJTTX6 100-500 psid l HIGH FIEW ISOLATION incredsing E31-N0llA.B.C.D MAIN STEAM LINE $ 111 psid 102AS-B305-NX-CIA-JJTTX6 100-500 psid HIGH FLOW ISOLATION incredsing E31-N012AA.BA RHR HIGH SUCTION F14W 5 180" W.C. 103AS-B203-NX-CIA-JJTTX6 20-200 in. W.C.
AB.BB ISOLATION (Shutdown incredsing Cooling)
E31-N013AA.BA RCIC HIGH STEAM $ 178" W.C. 1034S-B203-NX-CIA-JJTTX6 20-200 in. W.C.
AB.BB FIEW ISOLATION increasing I
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DOCUfEENT ID 41181
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f TABLE 2
- SUN RRY OF SETPOINT CHARACTERIZATION TESTS RESULTS FOR UNIT 2 124-HR. STATIC TEST l 24 HOUR STATIC l REPEATABILITY I REPEATABILITY l SWITCH APPLICATION I SAfFLE SIZE I PRESSURE SHIFT RESULTS l TEST SAffLE SIZE l RESULTS I l 1 l 1 i ,
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-CEACTOR VESSEL LEVEL 3 l 1001L l 2.2 - 6.1 INCHES W.C.(1) l 1001L l Less Then 2% l l (6 switches) l l (6 switches) l l
-REACTOR VESSEL LEVEL 2 I l . I l l l 44% l 2.5 - 6.9 INCHES W.C. l 1001L l Less Than 2% l l
-REACTOR VESSEL LEVEL 1 l (7 switches) i I (16 switches) l l
- I i 1 l l t
-REACTOR VESSEL LEVEL 8 l 100% l 3.4 INCHES W.C. l 100% l Less Then 2% I l (1 switch) I l (1 switch) l l i
-RHR/RCIC STEAMLINE BREAK ) l l l l l t
)I I I I I :"
-RHR SHUTDOW COOLING LINE) l 8% l 6 INCHES W.C. l 1001L l Less Then 2% I
)l (1 switch) l (Conservative) l (12 switches) l 1
-RCIC STEAM LINE BREAK
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-RHR LPCI-A B.C MIN. FIDW ) l l l l l ,
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-LPCS MIN. FLOW )l 251L l 3.1 INCHES W.C. l 62.5% l Less Then 41b l
)l (2 switches) l l (5 switches) l l [
-HPCS MIN. FLOW ) i I I I l 4 I I I I I
-MAIN STEAM LINE HI FLOW l 100% l 2 - 15.5 PSID l 100% l 1.45 - 10.5 PSID l l (16 switches) l l (16 switches) l l r
NOTES: (1) Switches exceeding 3.0 inches W.C. were replaced with switches that have a static shift of 3.0 inches W.C. or less.
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f DOCUMDfT ID 41181 ,
. I TABLE 2 .
SLNWIARY OF SETPOINT CHARACTERIZATION TESTS RESULTS FOR LMIT I l 24-Hour Static l 24-Hour Static l Repeatabilityl l l Pressure Test l Pressure Shift l Test Sample l l Swltch Application I Sample Size I Results I Size l Repeatability Results l l l l I I I l l 1 l l l l l l
-Ceactor vessel Level 3 l 100% [0.9"-5.4" w.C.(1)l 100% l Less Than 2% l l (6 switches) l l (6 switches) l I
-Ceactor vessel Level 2 l 100% l-0.9*-+5.0" W.C. I 100% l l l (12 switches) l l (12 switches)l Less Than 2% l
-C actor Vessel Level 1 l 100% l 2.9 -6.0" W.C. I 100% l l l (4 switches) l l (4 switches) l Less Than 2% l
-RHR/RCIC Steamline Break ) l l l l l
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-RHR Shutdone Cooling Line) l 100% l-6.9"-+6.3"W.C. l 100% l 0.3% to 3.3% (2) l
) l (12 switches) l l (12 switches)l l
-RCIC Steam Line Break )I l l l l l l l I l l l l l 1
-RHR LPCI-A.B.C Min. Flow ) l l l l I
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-LPCS Min. Flow ) l 37.5% l-2.08-+3.61*W.C. [ 100% l 0.5% to 11% l
) l (3 switches) l l (8 switches) l l
-HPCS Min. Flow ) l l l l l l I l l l
-Main Steam Line HI Flow l 100% l-1.3-7.7 PSID l 100% l 0.1% to 0.7% l l (16 switches) l l (16 switches)l l Notes: (1) Switches exceeding 3.0* W.C. were replaced with switches 3.0" W.C. or less.
(2) Switches with repeatability exceeding 2% of aljustable range will be replaced with switches with 2% or less.
DOCUENT ID 41181
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TABLE 3 SETPOINT CHARACTERIZATION TESTING CONCLUSIONS FOR UNIT 2 l
SWITCH APPLICATION I MARGIN FROM LCO l 1 l
1 l 4l EXISTING TECH I l EXISTING I NEW I STATIC SHIFT I REPEATABILITY I SPEC. DRIFT I TOTAL l L.C.O. l SETPOINT I I I l I 1
-REACTOR VESSEL LEVEL 3 l 4.2" RWL I 2.6* RWL i 1.5" RWL l 8.4" RWL l 11.0"RWL i19.4" RWL I I l 1 l 1
-REACTOR VESSEL LEVEL 2 l 11.2" RWL l 5.0" RWL l 7.0* RWL I 23.2" RWL I-57.0" RWL ! -33.8" RWL I I i i I l
-REACTOR VESSEL LEVEL 1 1 11.2" RWL l 7.3" RWL I 7.0* RWL l 25.5" RWL I-136.0" RWLl-l10.5" RWL l I I I I I
-DEACTOR VESSEL LEVEL 8 1 5.0" RWL l 2.6" RWL 1 0.5" RWL I 8.1" RWL I 56.0" RWL I 48.0" RWL I I I I I I
-RHR/RCIC STEAMLINE BREAK I 8.0" W.C. I 3.6" W.C. I 5.0" W.C. l 16.6" W.C. I 128" W.C. II11.4" W.C.
I I I I I I
-RHR SHUTDOWN COOLING LINE [ 8.0" W.C. I 3.6" W.C. l 6.0" W.C. I 17.6" W.C. l 186 W.C. 1168.4" W.C.
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-CCIC STEAM LIFE BREAK I 7.2% RATED FLOWI 3.0% RATED FLOW [ 5.0% RATED FLOW l 15.1% RATED 1295% RATED l 280% RATED I I I l FLOW IFLOW I FLOW I I I I I
-RHR LPCI-A.B.C MIN. FLOW I 237 GPM l 73 GPM i 450 GPM i 1423 GPMt 1 550 GPM Il 1973 GPMl I I I I I I
-LPCS MIN. FIrw l 233 GPM i 71 GPM l 110 GPM i 1079 GPM2 l 640 GPM i 1719 GPM l 1 I I l 1
-HPCS MIN. FLOW l 151 GPM i 50 GPM i 100 GPM i 640 GPM 8 1 900 GPM i 1540 GPM i i i I i 1
-MAIN STEAM LINE HI Flow l 10.5 PSID (5) l 15.5 PSID (5) l 5.0 PSID 1 31.0 PSID l 116 PSID I 85 PSID (5)
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NOTES: INCLUDES ADDITIONAL MARGIN OF 1) 663 GPM FOR LPCI 2) 664 GPM FOR LPCS AND 3) 339 GPM FOR HPCS
- 4) For applications other than main steam line high flow and EOCS minimuni flow, repeatability for each switch tested was less than 2% of range- therefore 2% was used for repeatability. For mainsteam line high flow and ECCS minimust flow switches, repeatability of the most variable switch in service was used.
- 5) It is planned to improve this value in the future by replacement of the worst performing switches with switches that have better repeatability and static offset performance.
DOCUMENT ID 41181
TABLE 3 LASALLE COUNTY UNIT 1 SETpOINT CHARACTERIZATION TESTING CONCLUSIONS Switch AppIlcatlon I Nrgin from LCO l l proposed l l (4)l Existing Tech l l Existing l New (6)
I Static Shift l Repeatability I Spec. Drift l Total l L.C.O. l Setpoint I I l 1 I l
-R: actor Vessel Level 3 l 4.2" RWL l 2.6" RWL l 1.5" RWL l 8.4" RWL l 11.0"RWL l19.4" RWL i I l i i 1
-Reactor Vessel Level 2 l 11.2" RWL l 5.0" RWL l 7.0" RWL l 23.2" RWL l-57.0" RWL l -33.8" RWL I l l l l l
-Coactor vessel Level 1 [ 11.2" RWL l 7.3" RWL l 7.0" RWL l 25.5" RWL l-136.0" RWLl-110.5" RWL I l 1 I I I
-RHR/RCIC Steamline Break l 8.0" W.C. I 3.6" W.C. l 5.0" W.C. l 16.6" W.C. I 128" W.C. [111.4" W.C.
I I I I I l
-DfR Shutdown Cooling Line l 8.0" W.C. I 3.6" W.C. l 6.0" W.C. l 17.6" w.C. l 186 W.C. l168.4" W.C.
I l 1 i l 1
-RCIC Steam Line Break l 7.2% rated flowl 3.0% rated flow 1 5.0% rated flow l 15.2% rated 1295% rated l 280% rated l l l l flow Iflow l flow I l 1 I I l
-RHR LpCI-A B.C Min. Flow l 268 gpa l 216 gpm l 450 gpm l 1423 gpm 1 l 550 gpm l 1973 gpa i I I I l 1
-LpCS Min. Flow l 265 gpa l 203 gpm l 110 gpm l 1079 gpm 2 l 640 gpm i 1719 spa l l l 1 I I
-HpCS Min. Flow l 171 gpm l 146 gpm l 100 gpa l 640 spa s l 900 gpm l 1540 gpm I l 1 I l l
-Main Steam Line HI Flow I 8.0 psid (5) l 5.4 psid (5) l 5.0 psid l 18.4 psid (5)l 116 psid l 97.6 psid (5) l I I l l l NOTES: Includes Additional Margin of I) 489 gym for LpCI 2) 501 gpm for LPCS and 3) 223 gpm for HpCS l
- 4) For applications other than main steam line high flow and ECCS minimum flow, repeatability for each switch tested was less than 2% of range; therefore 2% was used for repeatability. For mainsteam line high flow and ECCS minimum flow switches, repeatability of the most variable switch in service was used. Repeatability was Calculated for each switch to bound 95% of the population with a 95% confidence level.
- 5) It is planned to improve these values in the future by replacement of the worst performing switches with switches that have better repeatability and static offset performance.
- 6) Since 100% of the switches were tested on Unit 1, the static offset and repeatabilities are known for every switch. This allows a knowledgeable setting of the switch which is not dependent on a bounding margin established for Unit 2 switches. The values shown in this column represent Unit 2 setpoints with the exception of the setpoint for h in Steam Line High Flow switches. These setpoints may be changed in the future to take advantage of the more complete test data.
DOCUMENT ID 41181
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LASALLE COUNTY STATION UNIT 2 ,
TABLE 4 -
CORRECTIVE ACTIONS ;
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- 1. Final LaSalle County Station Unit 2 ,.
Completed SOR Investigation Report
- 2. Flow testing to verify RCCS ( ,'
, ' Completed minimum flow switch setpoints (
- 3. Reactor water level drop tests to verify ,During startup level 3 switch setpoints. Tests will be following performed at approximately 0.0 PSIG, 950 current outage PSIG, and 500 PSIG. The reactor wil1 .
at;d during shut-be held at 950 psig for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> down for the prior to the 950 psig Level Drop Test'. first refueling only one level drop test will be performed / outage (approx-at each pressure. ,
imately December j 1986).
i 4. Complete calibration procedure revisions , ,
Completed l a. New setpoints including: static pressure shift.,- 4 repeatability margin and drift margin. ,
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- b. New calibration methods including: The "as-four.d"
- setpoint will be the first actuation and'during-calibration the swit
- :h will be cycled from /
the appropriate 0% or 100% of differentia 1 pressure ,
4 span to the setpoint. 4 ,
, c. "As-found" setpoint acceptance limits j will be included into the procedures, and actions will be defined for each limit. The limits and actions will be the following:
(1) Action Limit (a) Except Main Steam Line High Flow and ECCS minimum flow, ,
l 1 3% of adjustable range from new '
calibration setpoint.
4 (b) For main steam line high flow ~,
i and ECCS minimum flow, this ,
! limit was 1.5X repeatability of the most variable switch in service.
Repeatability was calculated for i each switch to bound 95% of the dato with a 95% confidence level'.
(c) If this limit is exceeded,'incre$se l surveillance fregt:encies for the '
l switch. The next surveillance will be performed at the tieme interval as the last surveillance i within this limit. t ,
j (d) If this limit is exceeded during I the second consecutive surveillana , '
I the switch will be scheduled for
- replacement within'14 days.
l I DOCUMENT ID 41181 , )
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TABLE 4 (cont.)
LaSalle County Unit 2
- 4. Complete calibration procedure revisions (cont.)
- c. "As-found" setpoint acceptance limits (cont.)
(2) Rejection Limit (a) i (2% of adjustable range + tech.
spec. margin for drift)
(b) For main steam line high flow and ECCS minimum flow, switches this limit is (repeatability + tech.
spec. drift) for the most variable switch in service. Repeatability was calculated for each switch to 95% of the population with a 95%
confidence level.
(c) If this limit is exceeded the switch will be rejected, and appropriate actions will be taken in accordance with the LaSalle County Technical Specifications.
- 5. Complete recalibration of switches with revised setpoints and revised procedures. Prior to startup from current outage.
- 6. Implement Increased Surveillance After startup from current outage,
- a. The Level 3 switches will be calibrated 2 weeks after startup, 4 weeks after startup, 2 months after startup and 4 months after startup. After the fourth month, the level 3 switches will remain on a quarterly frequency. Note that this schedule assumes no problems occur with the limits as described above.
- b. Main Steam Line Break Switches (16 switches) l
- At least four of the main steam line (MSL) switches will be calibrated 4 weeks after startup. Of the remaining 12 switches, at least four of the MSL switches will be calibrated 8 weeks after startup. Of the remaining eight switches, at least four of the MSL switches will be calibrated 12 weeks after startup. The maximum interval for each individual switch will be limited to a quarterly frequency.
TABLE 4 (cont.)
(
LaSalle County Unit 2
- c. Remaining switches (37 switches) - A sample !
(grouped by model numbers) representative of the remaining switches (approximately 1/3) will be calibrated 4 weeks after startup. Of the remaining switches, approximately 1/3 will be calibrated 2 months after startup.
The remaining switches will be calibrated 3 months after startup. The maximum interval for each individual switch will be limited to a quarterly frequency. The representative samples will be chosen, where possible, to include a sampling of various switch model numbers.
- d. Switches placed in service that exceed the reject limit of this surveillance program will be sent to SOR for disassembly and
, inspection for cause of failure if the switch can be decontaminated and the cause of the failure if not obvious.
- 7. Complete evaluation of alternative level sensing instruments to replace SOR 1-1-87
- a. Review requirements i b. Review vendor environmental qualification data,
- c. Review vendor performance test data,
- d. Recommend technically acceptable alternatives,
- e. Complete preliminary conceptual design and obtain reviews and approval. General description of key features affecting design installation, operation and maintenance, and project plan,
- f. Initiate detailed conceptual design.
The alternative options being considered at this time' include:
- a. Installation of improved design SOR differential pressure switches.
- b. Replacement of switches with analog transmitter /
trip units
- 1) Partial replacement -- some applications.
- 2) Complete replacement -- all applications.
If other viable alternatives become available, they will be considered also.
- 8. Establish acceptance limits for new SOR Completed switches. The Purchase Order with SOR will
, be revised to require tests similar to setpoint characterization tests including a 24-hour test and to require switches perform within the static shift and repeatability limits.
TABLE 4 LaSalle County Unit 1 CORRECTIVE ACTIONS
- 1. Final LaSalle County Station Unit 1 This Executive SOR Investigation Report Sunusary ,
dated 9/5/86 l
- 2. Unit 1 Flow testing to verify BCCS Prior to Startup minimum flow switch setpoints
- 3. A reactor vessel level drop test will be 0.0 psig test performed at 0.0 psig in order to verify prior to startup system operability. The results of the 950 following psig level drop testing on Unit 2 was current outage, successful in proving that operability of and 950 psig the scram function may be relied upon by adjusting test greater the switch setpoints to take into account the than 3 months results found in the SOR setpoint characterization after startup program. Additional thermal cycles, pressure tests and at shutdown and other challenges to the Unit 1 safety system for the next equipment are not technically justified. refueling When plant conditions permit, a level drop test will outage.
be performed at approximately 950 psig during the first planned shutdown greater than 3 months after startup.
- 4. Complete calibration procedure revisions Week of 8-25-86
- a. New setpoints including: static pressure shift, repeatability margin and drift margin.
- b. New calibration methods including: The "as-found" setpoint will be the first actuation and during calibration the switch will be cycled from the appropriate 0% or 100% of differential pressure span to the setpoint.
- c. "As-found" setpoint acceptance limits will be included into the procedures, and actions will be defined for each limit. The limits and actions will be the following:
(1) Action Limit (a) Except Main Steam Line High Flow l and ECCS minimum flow, I
+ 3% of adjustable range from new calibration setpoint.
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l i DOCUMENT ID 41181 1
TABLE 4 (cont.)
LaSalle County Unit 1
- 4. Complete calibration procedure revisions (cont.)
- c. "As-found' setpoint acceptance limits (cont.)
(b) For main steam line high flow and ECCS minimum flow, this limit was 1.5X repeatability of the most variaN1e switch in service.
Repeatability eas calculated for each switch to bound 95% of the ;
population with a 95% confidence level.
(c) If this limit is exceeded, the next j surveillance will be performed at the same interval as the last successful surveillance within this limit.
(d) If this limit is exceeded during the second consecutive surveillance, the switch will be scheduled for replacement within 14 days.
1 (2) Rejection Limit (a) i (2% of adjustable range + tech.
spec. margin for drift)
(b) For main steam line high flow l
and ECCS minimum flow, switches this limit is (repeatability + tech.
spec. drift) for the most variable switch in service. Repeatability was calculated for each switch to 95% of the population with a 95%
confidence level.
(c) If this limit is exceeded the switch will be rejected, and appropriate actions will be taken in accordance with the LaSalle County Technical Specifications.
- 5. Complete recalibration of switches with revised setpoints and revised procedures. Prior to startup from current outage.
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( 6. Implement Increased Surveillance After startup from current outage,
- a. The Level 3 switches will be calibrated 2 l weeks after startup, 4 weeks after startup, 2 l months after startup and 4 months after
! startup. After the fourth month, the level 3 l switches will remain on a quarterly l frequency. Note that this schedule assumes no l problems occur with the limits as described l
above.
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DOCUMENT ID 41181
TABLE 4 (cont.)
LaSalle County Unit 1
- b. Main Steam Line Break Switches (16 switches)
- At least four of the main steam line (MSL) switches will be calibrated 4 weeks after startup. Of the remaining 12 switches, at least four of the MGL switches will ,be calibrated 8 weeks after startup. Of the remaining eight switches, at least four of the MSL switches will be calibrated 12 weeks after startup. The maximum interval for each individual switch will be limited to a quarterly frequency.
- c. Remaining switches (36 switches) - A sample (grouped by model numbers) representative of the remaining switches (approximately 1/3) will be calibrated 4 weeks after startup. Of ,
the remaining switches, approximately 1/3 will be calibrated 2 months after startup.
The remaining switches will be calibrated 3 months after startup. The maximum interval for each individual switch will be limited to a quarterly frequency. The representative samples will be chosen, where possible, to include a sampling of various switch model numbers. .
- d. Switches placed in service that exceed the reject limit of this surveillance program will be sent to SOR for disassembly and inspection for cause of failure if the switch can be decontaminated and the cause of the failure if not obvious.
- 7. Complete evaluation of alternative level sensing instruments to replace SOR l-1-87
- a. Review requirements
- b. Review vendor environmental qualification data,
- c. Review vendor performance test data,
- d. Recommend technically acceptable alternatives.
- e. Complete preliminary conceptual design and obtain reviews and approval. General description of key features affecting design installation, operation and maintenance, and project plan.
- f. Initiate detailed conceptQal design.
O TABLE 4 (cont.)
LaSalle County Unit 1 The alternative options being, considered at this time include:
- a. Installation of improved design SOR differential pressure switches.
- b. Replacement of switches with analog transmitter /
trip units
- 1) Partial replacement -- some Applications.
- 2) Complete replacement -- all applications.
If other viable alternatives become available, they will be considered also.
- 8. Establish acceptance limits for new SOR Completed switches. The Purchase Order with SOR will be revised to require tests similar to setpoint characterization tests including a 24-hour test and to require switches perform within the static shift and repeatability limits.
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