ML20209B460

Suppls 860725 Response to IE Bulletin 86-002, Static O-Ring Differential Pressure Switches. Switch Setpoints Will Be Revised Prior to Startup to Provide Addl Margin for Static Pressure Shift & Repeatability

ML20209B460
Person / Time
Site:	Byron
Issue date:	08/29/1986
From:	Johnson I COMMONWEALTH EDISON CO.
To:	James Keppler NRC, NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
2056K, IEB-86-002, IEB-86-2, NUDOCS 8609080237
Download: ML20209B460 (21)

Text

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I O; OnecFast Nabonel Plaza, CNce00. Ilhnois 4( m / Address Reply to: Poet Omco Box 757 N/ CNce00,isnois 80000 0767 l

August 29, 1986 Mr. James G. Keppler Regional Administrator  ;

U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL. 60137 l

Subject:

LaSalle County Station Units 1 and 2 NRC Docket No. 50-454 & 50-455 Supplemental Response to NRC IE Bulletin 86-02

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

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 I would be submitted upon completion of the Unit 1 test program. This information is now provided in Attachment I to this letter.

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.

8609080237 860829 PDR ADOCK 05000454 0 PDR d<

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E 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, l

I. M. Johnson Nuclear Licensing Administrator

/klj cc: U.S. NRC Document Control Desk Washington, DC. 20555 Resident Inspector-LaSalle SUBSCRIBED and S O N to b e f o r /e' m e t h i s _ day of (OutinY , , 1986 Notary Public Y f_,

2056K

I .

r ATTACHMENT 1 LASALLE COUNTY STATION, UNITS 1 AND 2 SUPPLEMENTAL RESPONSE TO IE BULLETIN NO. 86-02 STATIC-O-RING DIFFERENTIAL PRESSURE SWITCHES

i I

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 SOR 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 refueling outage 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 ECCS 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 SOR DP switches installed on both Units at LaSalle.

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 4

Tech. Spec. setpoint is exceeded and the required automatic action does not occur was also re-emphasized.

i

! 3. Special Testing of SOR DP Switches l 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 i cycling test and a 24-hour static pressure test. This testing program is

described in detail in Reference 2.

DOCUMENT ID 41181/1266W l

p.

on Unit 2, the static pressure cycling test was performed on all switches except for a few ECCS minimum flow switches. The performance of these switches was verified during BCCS system operation. On Unit 1, the static pressure cycling test was performed on all switches.

Por 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 switches as described above) was tested.

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 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, 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.

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 application, and performance of the 44 hour5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 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) ar.d static offset (time-pressure " soak") testing. Five of the eight ECCS minimum flow valve switches were not tested for static offset because the switch setpoint chosen allowed much more margin than the static offset measured from the three identical switches tested required.

A series of static pressure tests conducted over various time intervals up 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 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 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 testing program at SOR 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 SOR switches has been fully characterized prior to resuming operation. Because of this program and the augmented surveillance program described in Table 4, additional special tests are not anticipated.

DOCUMENT ID 41181/1266W 4

1 i

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 GE analysis, all of the switches except-for one switch on Unit 2 would have tripped within analytical limits (see Reference 2).

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 shown in Reference 6.

5. Interim Performance Monitoring Program 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 setpoints. The initial settings for the Unit 1 switches use the Unit 2 values, however, in the future these values may be changed to take advantage of the more complete test data.

6. Description of Corrective Actions i On the basis of the setpoint characterization tests, the setpoints of the differential pressure switches will be revised prior to startup to provide l additional margin for static pressure shift and repeatability. The revised setpoints and margins are listed in Table 3. These revisions will

insure that the SOR DP switches will meet their Technical Specification j requirements. Switches that do not meet the static shift and i repeatability acceptance limits given in Table 3 will be replaced. New i

switches will be tested to verify that they meet these limits.

i To provide additional assurances that the switches will function properly, j

the ECCS minimum flow switches have been tested at their new setpoints j during system operation, and reactor water level drop tests have been j 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

j. 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. The calibration procedures will 1

also be revised to require the instrument maintenance technician to record

the first actuation as the "as-found" and to eliminate the effects of cycling. Instead of cycling the switch between its trip and reset points, all actuations will be obtained by cycling from either zero or full-scale DP to simulate actual operating conditions. The procedures will also

! contain " action" and " rejection" limits. If a switch setpoint exceeds its I action but not its rejection limit, its surveillance frequency will be adjusted as described in table 4. If its setpoint exceeds the rejection c an es, the switch wkTf be re Ia$ek as he!chiOSd Yn Ta0$e y{ e su e DOCUMENT ID 41 81/1266W

r- ,

1 After startup, a quarterly surveillance frequency will be established on these switches. In addition, the 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. For Unit 1, an augmented surveillance frequency will also be implemented for level 3. (Refer to Table 4 for Unit I attached)

A complete description of the corrective actions that will be taken can be found in Table 4 and in Reference 5.

DOCUMENT ID 41181/1266W

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 Differential Pressue Switches".

3. Jul' 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.

1, 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. August 29, 1986, letter from C. M. Allen to H. R. Denton transmitting the Unit 1 Executive Summary.

DOCUMENT ID 41181/1266W

l TABLE 1 LIST OF INSTALLED SOR DP SWITCHES l

1 SWITCH InseER USE SETPOINT M00EL RANGE 821-N024A,8,C,D LOW REACTOR 1 +12.5" RWL l MTER LEVEL ($ 63.78" W.C.

l 3-LOW LEVEL ir. creasing) 103AS-8212-NX-CIA-JJTTX6 7-100 in. W.C.

SCR M AND PCIS GROUPS 6 AND 7 821-NO26AB,88 REACTOR M TER 1 -50* RWL C8,08 LEVE:. -2 PCIS ($ 145.6" W.C. 103AS-88203-NX-C1A-JJ1TX6 20-200 in. W.C.

i GROUPS 1 THRU 5 increasing) 821-NO31A,8,C,D REACTOR WTER 1 -50" RWL LEVEL 2 - (5 145.6" W.C. 103AS-8203-NX-ClA-JJTTX6 20-200 in. W.C. s HPCS INITIATION increasing 821-NO37A8,88 REACTOR MTER LEVEL 1 -50" 18dL C8,DB RCIC INITIATION ($ 145.6" W.C. 103AS-8203-NX-C1A-JJITX6 20-200 in. W.C.

increasing) 103AS-88205-NX-CIA-JJTTX6 40-300 in. W.C.

821-NO37AA,BA REACTOR M TER LEVEL 2 -129" RML CA.DA 1-ECCS INITIATION ($ 202.2" W.C.

increasing) 821-NO38A,8 REACTOR MTER 1 +12.5" RWL LEVEL 3- ($ 63.78" W.C. 103AS-8212-NX-CIA-JJTTX6 7-100 in. W.C.

A05 PE MISSIVE increasing) 00CtMENT ID 4118i/1266W

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l TABLE 1 LIST OF INSTALLED SOR OP SWITCHES l

SWITCH l

laster USE SETPOINT MODEL RANGE 2E12-N010AA OPENS RHR A MIN FLOW 1 1000 gpm l

BYPASS VALVE ON LOW (t 5.9" W.C.

FLOW decreasing) l A8 ALARM SWITCH 1 1500 gpm 103AS-8202-NX-CIA-JJTTX7 5-35 in W.C.

(1 13.3" W.C.

decreasing)

BA OPENS RHR 8 MIN FLOW 3 1000 gpm BYPASS VALVE ON LOW (1 5.9" W.C.

FLOW decreasing) 98 ALARM SWITCH 1 1500 gpm (1 13.3" W.C.

decreasing)

CA OPENS RHR C MIN FLOW t 1000 gpm BYPASS VALVE ON LOW (1 5.9" W.C.

FLOW decreasing)

CB ALAfut SWITCH 2 1500 gpm (1 13.3" W.C.

decreasing)

E21-N004 OPENS LPCS MINIMUM 1 750 gym 103AS-8202-NX-CIA 4JTTX7 5-15 in. W.C.

FLOW BYPASS VALVE ON ( t 4.38" W.C.

LOW FLOW decreasing)

E22-N006 OPENS HPCS MIN FLOW t 1000 gpm 103AS-8202-NX-CIA-JJTTX7 5- 35 in. W.C.

BYPASS VALVE ON LOW (1 9.7" W.C.

FLOW decreasing) 821-N1018 RX LEVEL 8-RCIC TRIP $ 55.5" RWL 103AS-8212-NX-CIA-JJTTX6 7-100 in. W.C.

(Unit 2 only) (t 33.5" W.C.

decreasing)

E31-N007AA,A8 RCIC/RHR HIGH STEAM $ 123" W.C. 103AS-8203-NX-CIA-JJTTX7 20-200 in. W.C.

LINE FLOW ISOLATION increasing E31-N007BA,88 RCIC/RHR HIGH STEAM $ 87" W.C. 103AS-8203-NX-C1A-JJTTX7 20-200 in. W.C.

LINE FLOW ISOULTION increasing 00CisENT ID 4118i/1266W

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TABLE 1 LIST OF INSTALLED SOR OP SWITCHES SWITCH INAGER USE SETPOINT MDOEL RANGE E31-N0004,B,C,0 MIN STEM LINE S 111 psid 102AS-8305-M-CIA-JJTTX6 100-500 psid HIGH FLOW ISOLATION increasing E31-N0094,B.C,0 MIN STEM LINE S 111 psid 102AS-8305-NX-C1A-JJTTX6 100-500 psid HIGH FLOW ISOLATION increasing E31-N010A,8,C,D MIN STEM LINE S 111 psid 102AS-8305-NX-CIA-JJTTX6 100-500 psid HIGH FLOW ISOLATION increasing E31-N011A,B.C.D MIN STEM LINE S 111 psid 102AS-8305-NX-CIA-JJTTX6 100-500 psid HIGH FLOW ISOLATION increasing E31-N012AA,BA RHR HIGH SUCTION FLOW $ 190" W.C. 103AS-8203-NX-CIA-JJTTX6 20-200 in. W.C.

AB,98 ISOLATION (Shutdown increasing Cooling)

E31-N013AA,8A RCIC HIGH STEM $ 178* W.C. 103AS-8203-NX-CIA-JJTTX6 20-200 in. W.C.

AS,98 FLOW ISOLATION increasing 00 Cts 4ENT ID 41181/1266W

l TABLE 2 SissNlRY OF SETPOINT CHARACTERIZATION TESTS R~SULTS FOR LAIIT 2 l24-HR. STATIC TEST l 24 HOUR STATIC l REPEATASILITY l REPEATASILITY l SWITCH APPLICATION l SAfFLE SIZE I PRESStmE SHIFT RESULTS I TEST SAfPLE SIZE l RESULTS l l l l l l l l l l l l l l l l

-aEACTOR VESSEL LEVEL 3 l 100E l 2.2 - 6.1 INCHES W.C.(1) l 1005 l Less Than 25 l l (6 switches) l l (6 switches) l l

-aEACTOR VESSEL LEVEL 2 l l . l l l l 441 l 2.5 - 6.9 INCHES W.C. I 100E l Less Than 25 l

-aEACTOR VESSEL LEVEL 1 l (7 switches) l l (16 switches) l l l l l l l

-aEACTOR VESSEL LEVEL 8 l 1005 l 3.4 INCHES W.C. l 1005 l Less Than 25 l l l (1 switch) l l (1 switch) l l

-aHR/RCICSTEAnLINEBREAK)l l l l l

)l l I l l

-aHR ShUTD0hm COOLING LINE) l SE l 6 INCHES W.C. l 1001 l Less Than 25 l l )l (1 switch) l (Conservative) l (12 switches) l l l -aCIC STEAM LINE BREAK )l l l l l l l l l l l l l l l l l

-aHR LPCI-a 8.c nIN. rtou i l l l l l

)l l l l l

-tPCS nIN. FLOW )l 25s l 1.5 INCHES W.C. l 62.5% l Less Than 25 l

)l (2 switches) l l (s switches) l l t -wCS nIN. rtou )l l l l l ,

l l l 1 l

-MIN STEAM LINE HI Flou l 100K l 2 - 15.5 PSID l 1005 l1.45-10.5PSIO l

! l (16 switches) l l (16 switches) l l 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.

l l

l l

00C1REENT ID 41181/1266W

j TABLE 2 SuustRY OF SETPOINT CHARACTERIZATION TESTS RESULTS FOR tseIT 1 l

l 24-Hour Static l 244 tour Static l Repeatabilityl l lPressureTest l PressureShiftlTestSample l l Switch Aeolication l Sample Size l Results l Size l Repeatability Results l I I I I l I l l l l 1 1 I I l 1 -Aeactor Wessel Level 3 l 100E l0.9*-5.4*W.C.(1)l 1005 l Less Than 3 l l (6 switches) l l(6 switches)l l l -Aeactor Wessel Level 2 l 1001 l-0.9%5.0"W.C.l 100E l l l

l (12 switches)l l(12 switches)l Less Than 25 l

-Reactor Wessel Level 1 l 100E l2.9*-6.0*W.C. l 100E l l l l (4 switches) l l(4 switches)l Less Thar. 21 l

-RHR/RCIC Stemaline Break ) l l l l l i )I i l 1 l

-asst Shutdown Cooling Line) l 100E l-6.9"-+6.3"W.C. l 1005 l 0.35 to 3.35 (3) l

)l (12 switches)l l(12 switches)l l l -ACIC Steam time Break )l l l l l l

l l l 1 I l l l 1 I i l -aHRLPCI-A,8,CMin. Flow)l l l l l l )l l l 1 1

-tPCS Min. Flow )l 37.5% l-2.08-+3.61"W.C.l 1001 l 0.55 to 11% (3) l

)l (3 switches) l l(8 switches)l l

-HPCS Min. Flow )l l l l l 1 I I i l

-Main Stean Line HI Flow l 1005 l-1.3-7.7PSID l 100E  ! 0.1% to 0.7% (2) 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) Baseo on data from 8 out of 16 switches.

(3) Switches with repeatability exceeding 21 of adjustable range will be replaced with switches with 21 or less.

DOCUMENT ID 4118i/1266W

TABLE 3 SETPOINT CHARACTERIZATION TESTING CONCLUSIONS FOR UNIT 2 SWITCH APPLICATION l MARGIN FROM LCO l l l l 4l EXISTING TECH l l EXISTING l NEW l STATIC SHIFT l REPEATABILITY l SPEC. DRIFT l TOTAL l L.C.O. lSETPOINT l l l l l l

-REACTOR VESSEL LEVEL 3 1 4.2" RWL l 2.6" RWL l 1.5" RWL l 8.4" RWL l11.0"RWL l19.4"RWL i

l I I i i I

-REACTOR VESSEL LEVEL 2 l 11.2" RWL l 5.0" RWL l 7.0" RWL l23.2"RWL l-57.0"RWLl-33.8"RWL l I i i i 1

-REACTOR VESSEL LEVEL 1 l 11.2" RWL l 7.3" RWL l 7.0" RWL l25.5"RWL l-136.0"RWLl-110.5"RWL i I I I I i

-REACTOR VESSEL LEVEL 8 l 5.0" RWL i 2.6" RWL l 0.5" RWL l 8.1" RM. l56.0"RW1.l48.0"RWL 4 I I I I I I

8.0" W.C. 3.6" W.C. 5.0" W.C.

-RHR/RCIC STEAMLINE BREAK l l l l16.6"W.C. l128"W.C.l111.4"W.C.

I I I I I i

] -RHR SHUTD0les COOLING LINE l 8.0" W.C. l 3.6" W.C. l 6.0" W.C. l17.6"W.C. l186"W.C.l168.4"W.C.

I I I I I I

-RCIC STEAM LINE BREAK l7.2%RATEDFLOWI3.0%RATEDFLOWj5.0%RATEDFLOWl15.2% RATED l295% RATED l280% RATED 4

l l l l FLOW l FLOW l FLOW I I I I I I

-RHR LPCI-A,8,C MIN. FLOW l 237 GPM l 73 GPM l 450 GPM l 1427 GPM l550GPM l1977GPM i i I i i 1

-LPCS MIN. FLOW l 233 GPM l 71 GPM l 110 GPM l 1079 GPM2 l640GPM l1719GPM f

I I I I I I

-HPCS MIN. FLOW l 151 GPM i 50 GPM l 100 GPM l640GPM3 l900GPM l1540GPM j l i I I I I

-MAIN STEAM LINE HI FLOW l10.5PSID(5) l15.5PSID(5) l 5.0 PSID l31.0PSID l116PSID l 85 PSID (5) t i I I I I I NOTES: INCLUDES A00ITIONAL MARGIN OF 1) 666 GPM FOR LPCI 2) 664 GPM FOR LPCS AND 3) 329 GPM FOR HPCS

~

4) For applications other than main steam line high flow, repeatability for each switch tested was less than 2%

of range; therefore 2% was used for repeatability. For mainsteam line high flow switches, repeatability of

! the most variable switch in service was used.

1

5) It is planned to i grove this value in the future bg g lac nt of the worst performing switches with DOCUMENT ID 41 b ~

4

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TABLE 3 tASALLE COUNTY UNIT 1 SETPOINT CHARACTERIZATION TESTING CONCLUSIONS Switch Application l Margin from LCO I l Proposed 1 I (4)I Existing Tech l l Existing i New (6) l Static Shift l Repeatability l Spec. Drift l Total l L.C.O. ISetpoint i I l l l 1

-Reactor Vessel Level 3 1 4.2" RWL I 2.6" RWL l 1.5" RWL l 8.4" RWL I11.0"RWL 119.4"RWL I I I I I l

-Reactor Vessel Level 2 1 11.2" RWL l 5.0" R6;L l 7.0" RWL l23.2"RWL I-57.0"RWLI-33.8"RWL I I I I I i

-Reactor Vessel Level 1 I 11.2" RWL I 7.3" RWL l 7.0" RWL I25.5"RWL I-136.0"RWLI-110.5"RWL I I I I I I

-RHR/RCIC Steamline Break I 8.0" W.C. I 3.5" W.C. I 5.0" W.C. I16.6"W.C. I128"W.C.1111.4"W.C.

I I I I I I

-RHR Shutdown Cooling Line 1 8.0" W.C. I 3.6" W.C. I 6.0" W.C. I17.6"W.C. I186"W.C.l168.4"W.C.

l l 1 1 I I

-RCIC Steam Line Break l7.2%ratedflowl3.0%ratedflowI5.0%ratedflowI15.2% rated 1295%ratedi280% rated l l l 1 flow Inow I now J

l l l l l 1

-RHR LPCI-A,B,C Min. Flow I 237 gpm I 73 gpm I 450 gpm i 1427 gpal I550gpm i1977gpm I I I I I I

-LPCS Min. Flow I 233 gpm I 71 gpm i 110 Spm i 1079 gpm2 1640gpm i1719gpm l l l l l 1

-HPCS Min. Flow I 151 gpm I 50 gpm i 100 gpm l640gpm3 l900gpm i1540gpm l l l 1 1 I

-Main Steam Line HI Flow l8.0psid(5) I 5.4 psid (5) l 5.0 psid l18.4psid(5)l116psid I 97.6 psid (5) l l l 1 I I NOTES: Includes Additional Margin of 1) 666 gpm for LPCI 2) 664 gpm for LPCS and 3) 339 gpm for HPCS

4) For applications other than main steam line high flow, repeatability for each switch tested was less than 2% .

of range; therefore 2% was used for repeatability. For mainsteam line high flow switches, repeatability of the most variable switch in service was used. Repeatability was calculated for each switch to bour.d 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.swit h which is not dependent on a bounding margin established for Unit 2 switches. The values shown in this olumn represent Unit 2 setpoints. Unit I values could be made less conservative than these since more data is available.

DOCUMENT ID 4118i/1266W

LASALLE COUNTY STATION UNIT 2 TABLE 4 CORRECTIVE ACTIONS

1. Final LaSalle County Station Unit 2 Completed SOR Investigation Report

2. Flow testing to verify BCCS 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 will and 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 1986).

l

4. Complete calibration procedure revisions Completed

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, 1 3% of adjustable range from new calibration setpoint.

l (b) For main steam line high flow this limit was 1.5X repeatability of the most variable switch in service.

Repeatability was calculated for each switch to bound 95% of the data with a 95% confidence level.

(c) If thic limit is exceeded, the next surveillance will be performed at the same interval as the last i successful surveillance

. within this limit.

I (d) If this limit is exceeded during the second consecutive surveillance, .

the switch will be scheduled for replacement within 14 days.

DOCUMENT ID 41181/1261W

LASALLE COUNTY STATION UNIT 2 TABLE 4 CORRBCTIVE ACTIONS

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 switches this Itmit is (repeatability + tech.

spec. drift) for the most variable switch in service. Repeatability was calculated for each switch to 95% of the data with a 95%

confidence level.

(c) If this limit is exceeded the switch will be rejected and appropriate actions will be taken IAW LSCS Tech Specs.

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. Categories

1. Level 3 switches (6 switches) - 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, t

the level 3 switches will remain on a quarterly frequency. Note that this schedule assumes no problems occur with the limits as described above.

2. 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 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.

3. 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 DOCUMENT ID /S W

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' _ _ . _ . , _ , , . _ _ _ ~

LASALLE COUNTY STATION UNIT 2 TABLE 4 CORRECTIVE ACTIONS

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 conceptual design.

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.

DOCUMENT ID 41181/1266W

TABLE 4 LaSalle County Unit 1 CORRBCTIVE ACTIONS

1. Final LaSalle County Station Unit 1 This Executive i SOR Investigation Report Summary, dated 8/29/86

2. Unit 1 Flow testing to verify ECCS Prior to Startup minimum flow switch setpoints

3. A reactor vessel level drop test will be Prior to startup performed at 0.0 psig in order to verify following system operability. current outage and at shutdown

. for the next I refueling outage.

4. Complete calibration procedure revisions Week of 8-25-86 l

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.

i 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, i 3% of adjustable range from new calibration setpoint.

i (b) For main steam line high flow this

! limit was 1.5X repeatability of the most variable switch in service.

l Repeatability was calculated for each switch to bound 95% of the population with a 95% confidence level.

(c) If this limit is exceeded, the next I surveillance will be performed at

' the same interval as the last successful surveillance within this limit.

l (d) If this limit is exceeded during the second consecutive surveillance, the switch will be scheduled for replacement within 14 days.

l l DOCUMENT ID 41181/1266W

TABLE 4 (cont.)

LaSalle County Unit 1

4. Complete calibration procedure revisions (cont.)

c. "As-found" setpoint acceptance limits (cont.)

(2) Rejection Limit (a) 1 (2% of adjustable range + tech.

spec. margin for drift)

(b) For main steam line.high 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. Level 3 switches (6 switches) - Based on the successful two-week calibration performed on the Unit 2 Level 3 switches, in which all six switches were found to be within 1 0.6" W.C. of their initial settings, the surveillance cycle will be initially supplemented with more frequent inspections, as follows: Two of the four SCRAM switches (one in each channel) will be surveilled after one month. The other two SCRAM switches will be surveilled after the second month. The two ADS permissive switches will be surveilled after the third month. Dependent on satisfactory results from these surveillances, the switches will then be surveilled on a quarterly basis.

l DOCUMENT ID 41181/1266W l

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l 1

1

. - l 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 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.

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.

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 conceptual design.

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.

DOCUMENT ID 41181/1266W l

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