ML20209J265

Suppls 860725 Response to IE Bulletin 86-002,per NRC 860905 Telcon Request.Summary of Testing Performed on Static O-Ring Series 102 & 103 Differential Pressure Switches & Description of Corrective Actions Prior to Startup Encl

ML20209J265
Person / Time
Site:	LaSalle
Issue date:	09/08/1986
From:	Johnson I COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20209J253	List: ML20209J247 ML20209J265
References
2076K, 4118I, IEB-86-002, IEB-86-2, NUDOCS 8609160269
Download: ML20209J265 (22)

Text

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' N-v'/ Address Reply to: Post Omco Chca0o, IEncis 60600 0767 Box 767 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 j NRC Docket No. 50-454 u . . 50-3-) 3 +- So - 37 V 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

(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 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 103 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 both units 1 and 2. This revised response is provided in Attachment 1 to the letter.

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4 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, m

I. M. Johnson Nuclear Licensing Administrator

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I cc: U.S. NRC Document Control Desk Washington, DC. 20555 Resident Inspector-LaSalle I SUBSCR BED and RN to befor me thip day of_ J : ~ A lts s' , 1986

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• O ATTACHMENT 1 REVISED LASALLE COUNTY STATION. UNITS 1 AND 2 SUPPLEMENTAL RESPONSE TO IE BULLETIN NO. 86-02 STATIC-O-RING DIFFERENTIAL PRESSURE SWITCHES, SEPTEMBER 1986 i

LASALLE COUNTY STATION. UNITS 1 AND 2 RESPONSB 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 quarter of 1985 and during the I

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 ADDlication 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 installed on both Units at LaSalle in both safety and non-safety related applications.

2. Operator Training All licensed shift personnel have been trained on the June 1 event et LaSalle Unit 2 with regard.s to the SOR DP switches. This training included a discussion of where the switches are installed, their functions, and their setpoints. The " Conduct of Operationu" 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 Testing 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.

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

i 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 ECCS 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 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, j the test results on this sample bounded all of the switches for that 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.

ll As stated above, the test program on Unit I was more comprehensive in that l

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 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 l 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. i 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. l DOCUMENT ID 41181

4. Test Results/Pailures 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 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 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. DescriDtion 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

! revised setpoints and margins are listed in Table 3. These revisions will insure that the SOR Dp switches will meet their Technical Specification i

requirements. Switches that do not meet the static shift and repeatability acceptance limits given in Table 3 will be replaced. New switches will be tested to verify that they meet these limits.

To provide additional assurances that the switches will function properly, the ECCS minimum flow switches have been tested at their new setpoints 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 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 be performed at shutdown for the second refueling outage. When plant 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 "as-found" and to eliminate the effects of cycling. Instead of cycling l

DOCUMENT ID 41181

, . the switch between its trip and rs It points, all tctuationJ Will be obtcined by cycling from eithIr zsro cr full-Ecale DP to simulate tctual 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 additiori, 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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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. 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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TABLE 1 LIST OF INSTALLED SOR DP SWITCHES .

SWITCH NUMBER .USE SETPOINT MODEL RANGE f B21-N024A,B,C,D LOW REACTOR 1 +12.5" RWL .

i WATER LEVEL ($ 63.78" W.C.

3-LOW LEVEL increasing) 103AS-B212-NX-CIA-JJTTX6 7-100 in. W.C.

SCRAM AND PCIS l GROUPS 6 AND 7 i

- C21-N026AB,BB REACTOR WATER 2 -50" RWL

CB.DB LEVEL -2 PCIS (s 145.6" W.C. 103AS-BB203-NX-CIA-JJTTX6 20-200 in. W.C.

-l GROUPS 1 THRU 5 increasing) i B21-NO31A.B.C,D REACTOR WATER h -50" RWL LEVEL 2 - (s 145.6" w.C. 103AS-B203-NX-CIA-JJTTX6 20-200 in. W.C.

HPCS INITIATION increasing i

B21-NO37AB,BB REACTOR WATER LEVEL 1 -50" kWL 1 CB.DB RCIC INITIATION ($ 145.6" W.C. 103AS-B203-NX-CIA-JJTTX6 20-200 in. W.C.

! increasing) 3 103AS-BB205-NX-CIA-JJTTX6 40-300 in. W.C.

i B21-NO37AA,BA REACTOR WATER LEVEL 1 -129" RWL j CA.DA 1-ECCS INITIATION ($ 202.2" W.C.

i increasing)

I j C21-NO38A,B REACTOR WATER E +12.5" RWL LEVEL 3- (s 63.78" W.C. 103AS-B212-NX-CIA-JJTTX6 7-100 in. W.C.

] ADS PERMISSIVE increasing)

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1I DOCUMENT ID 41181 I

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, - - - - - - m TABLE 1 LIST OF INSTALLED SOR DP SWITCHES .

SWITCH .

i NUMBER USE SETPOINT MODEL RANGE I

2E12-N010AA OPENS RHR A MIN FLOW > 1000 gpm .

i BYPASS VALVE ON LOW (1 5.9" W.C.

FLOW decreasing)

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 i BYPASS VALVE ON LOW (2 5.9" w.C.

FLOW decreasing)

BB ALARM SWITCH E 1500 gpm j

(2 13.3" W.C.

decreasing)

! CA OPENS RHR C MIN FLOW 2 1000 gpm BYPASS VALVE ON LOW (1 5.9" W.C.

FLOW decreasing)

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

decreasing) 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.

LOW FLOW decreasing)

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

BYPASS VALVE ON LOW (2 9.7" W.C.

FLOW decreasing) 021-N101B RX LEVEL 8-RCIC TRIP 5 55.5" RWL 103AS-B212-NX-CIA-JJTTX6 7-100 in. W.C.

(Unit 2 only) (1 33.5" W.C.

decreasing)

E31-N007AA.AB RCIC/RHR HIGH STEAM s 123" W.C. 103AS-B203-NX-CIA-JJTTX7 20-200 in. W.C.

LINE FLOW ISOLATION increasing E31-N007BA.BB RCIC/RHR HIGH STEAM $ 87" W.C. 103AS-B203-NX-CIA-JJTTX7 20-200 in. W.C.

LINE FLOW ISOLATION lucreasing DOCUMENT ID 41181

TABLE 1 LIST OF INSTALLED SOR DP SWITCHES .

SWITCH .

NUPELER USE SETPOINT MODEL RANGE E31-N008A.B.C.D MAIN STEAM LINE $ 111 psid 102AS-B305-NX-CIA-JJTTX6 100-500 psid -

HIGH FLOW ISOIATION increasing E31-N009A.B.C.D MAIN STEAM LINE $ 111 psid 102AS-8305-NX-CIA-JJTTX6 100-500 psid HIGH FLOW ISOLATION incredsing E31-N010A.B.C.D MAIN STEAM LINE $ 111 psid 102AS-B305-NX-CIA-JJTTX6 100-500 psid HIGH FLOW ISOLATION increasing E31-N0llA.B.C.D MAIN STEAM LINE s 111 psid 102AS-B305-NX-CIA-JJTTX6 100-500 ps,id HIGH FLOW ISOfATION incredsing E31-N012AA.BA RHR HIGH SUCTION FLOW $ 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. 103AS-B203-NX-CIA-JJTTX6 20-200 in. W.C.

AB.BB FLOW ISOtATION increasing DOCUMENT ID 41181

r TABLE 2 SUpWULRY OF SETPOINT CHARACTERIZATION TESTS RESULTS FOR UNIT 2 -

[24-HR. STATIC TEST l 24 HOUR STATIC l REPEATABILITY l REPEATABILITY l SWITCH APPLICATION I SAM LE SIZE l PRESSURE SHIFT RESULTS l TEST SAM LE SIZE l RESULTS l l l l l l l l l l l l l l l l

-CEACTOR VESSEL LEVEL 3 l 100% l 2.2 - 6.1 INCHES W.C.(1) l 100% l Less Than 2% l l (6 switches) l ] (6 switches) l l

-REACTOR VESSEL LEVEL 2 l l . l l l l 44% l 2.5 6.9 INCHES W.C. l 100% l Less Than d l

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

-REACTOR VESSEL LEVEL 8 l 100% l 3.4 INCHES W.C. l 100% l Less Then 2% l l (1 switch) l l (1 switch) l l

-RHR/RCIC STEAMLINE BREAK ) l l l l l

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-CHR SHUTDOWN COOLING LINE) l 8% l 6 INCHES W.C. l 100% l Less Than 2% l

) l (1 switch) l (Conservative) l (12 switches) l l

-RCIC STEAM LINE BREAK ) l l l l l l l l l l l l l l l

-RHR LPCI-A,B.C MIN. FLOW ) l l l l l

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-LPCS NIN. FLOW )l 25% l 3.1 INCHES W.C. l 62.5% l Less Than 4% l

)l (2 switches) l l (5 switches) l l

-HPCS MIN. FLOW )l l l l l l l l l l

-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 NOT'.S: (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.

DOCUMENT ID 41181

TABLE 2 , .

SUf9ERY OF SETPOINT CHARACTERIZATION TESTS RESULTS FOR UNIT 1 .

I 24-lhar Static l 24-Hour Static l Repeatab111tyl l l Pressure Test i Pressure Shift l Test Sample l l .

. Switch Application i Sageple Size 1 9esults l Size I Repeatability Results i 1 l l l l 1 l 1 l l l l l l l

-Rsoctor Vessel Level 3 l 100% l0.9"-5.4" W.C.(1)l 100% l Less Than 2% l l (6 switches) l

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-Reactor Vessel Level 2 l 100% l-0.9"-+5.0" W.C. l 100% l l l (12 switches) l l (12 switches)l Less Than 2% l

-Retutor 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

-RiiR/RCIC Ste.imline Break ) { l l l l

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-RHR Shutdown 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

-RClc Stee:u Line Break )l l l 1 l l l 1 I l l l 1 I I

-RhR ISCI-A.B.C Min. Flow ) l l 1 I l

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-LPCS Min. Flow ) i 37.5% l-2.08-+3.61"W.C. l 100% l 0.5% to 11% l

)1 (3 switches) l l (8 switches) l l

-npcs Hin. Flow )l l l l l 1 l l l 1

-Main Steam Line HI Flow I 100% l-1.3 ~1.7 PSID .l 100% l 0.1% to 0.7% l l (16 switches) l l (16 switches)l l Notes: (O Switches exceeding 3.0" W.C. were replaced with switches 3.0" W.C. or less.

'(2I w itches with repeatability exceeding 2% of adjustable range will be replaced with switches with 2% or less.

DOCUMENT ID 41181 L

r q TABLE 3 SETPOINT CHARACTERIZATION TESTING .

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

-REACTOR VESSEL LEVEL 3 1 4.2" RWL I 2.6" RWL l 1.5" RWL l 8.4" RWL l 11.0"RWL i19.4" RWL i I l l l 1

-REACTOR VESSEL LEVEL 2 1 11.2" RWL I 5.0" RWL l 7.0" RWL l 23.2" RWL I-57.0" RWL l -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 I 25.5" RWL l-136.0" RWLl-l10.5" RWL I I I I I l

-REACTOR VESSEL LEVEL 8 l 5.0" RWL l 2.6" RWL l 0.5" RWL I 8.1" RWL I 56.0" RWL I 48.0" RWL l l 1 I I l

-RHR/RCIC STEAMLINE BREAK I 8.0" W.C. I 3.6" W.C. l 5.0" W.C. I 16.6" W.C. l 128" W.C. I111.4" W.C.

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-RHR SHUTDOWN COOLING LINE l 8.0" W.C. l 3.6" W.C. l 6.0" W.C. I 17.6" W.C. l 186" W.C. I168.4" W.C.

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-RCIC STEAM LINE BREAK I 7.2% RATED FLOW l 3.0% RATED FLOW I 5.0% RATED FLOW I 15.2% RATED l295% RATED I 280% RATED 1 1 I l FLOW IFLOW I FLOW l 1 1 I I I

-RHR LPCI-A B.C MIN. FLOW I 237 GPM i 73 GPM l 450 GPM l 1423 GPMz I 550 GPM i 1973 GPM l l l l l l 1

-LPCS MIN. FLOW I 233 GPM i 71 GPM l 110 GPM l 1079 GPM2 1 640 GPM i 1719 GPM i I l 1 l 1

-HPCS MIN. FLOW l 151 GPM l 50 GPM l 100 GPM l 640 GPM* l 900 GPM i 1540 GPM i i I i I l

-MAIN STEAM LINE HI FLOW I 10.5 PSID (5) I 15.5 PSID (5) 1 5.0 PSID l 31.0 PSID l 116 PSID 1 85 PSID (5) 1 I I I l l l

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 steams 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.

5) It is planned to improve this value in the future by rsplacement of the worst performing switches with switches that have better repeatability and static offset performance.

DOCUMENT ID 41181 L_

TABLE 3 LASALLE COUNTY UNIT 1 l SETPOINT CHARACTERIZATION TESTING CONCLUSIONS ,

) Switch Applicatiott I Margin from LCO l l Proposed j i l (4)l Existing Tech i I Existing l New (6) .

! l Static shift l Repeat 4bility l Spec. Drift l Total l L.C.O. l Setpoint I l l l l 1 1 1 -Rroctor Vessel Level 3 1 4.2" RWL l 2.6" RWL l 1.5" RWL l 8.4" RWL l 11.0"RWL i19.4" RWL 1 1 I l l l 1

] -Reactor Vessel Level 2 1 11.2" RWL I 5.0" RWL l 7.0" RWL l 23.2" RWL l-57.0" RWL l -33.8" RWL J

l l l l l l j -Rrector Vessel Level 1 1 11.2" RWL l 7.3" RWL I 7.0" RWL l 25.5" RWL l-136.0" RWLl-110.5" RWL i I i I l l 1

-RHR/RCIC Steamline Break I 8.0" W.C. I 3.6" W.C. l 5.0" W.C. l 16.6" W.C. l 128" W.C. I111.4" W.C.

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-RHR Shutdown Cooling Line l 8.0" W.C. l 3.6" W.C. l 6.0" W.C. l 17.6" W.C. l 186" W.C. l168.4" W.C.

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-RCIC Steam Line Break I 7.2% rated flowl 3.0% rated flow l 5.0% rated flow l 15.2% rated 1295% rated l 280% rated I l l l flow l flow l flow i I l l l I 1

! -RHR LPCI-A,B.C Min. Flow I 268 gpm l 216 gpm l 450 gpm l 1423 gpa l l 550 gpa l 1973 gpm I l l l l l

-LPCS Min. Flow l 265 gpm 1 203 gpm i 110 gym l 1079 gpm 2 l 640 gpm l 1719 gpa

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-HPCS Min. Flow l 171 gpm i 146 gpm l 100 gpa i 640 gpm* l 900 gym l 1540 gpm l l 1 l l l

-Main Steam Line HI Flow l 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 1 l I I I NOTES: Includes Additional Margin of 1) 489 gpa for LPCI 2) 501 gpm for LPCS and 3) 223 gpm for HPCS 1

l l 4) For applications other than main steam line high flow dnd ECCS minimum flow, repeatability for each switch tested was less than 2% of rdnge; therefore 2% was used for repeatebility. For mainsteam line high flow and ECCS minimum flow switches, repeatability of the most variable switch in service was used. Repeatebility 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 Mein Steam Line High Flow switches. These setpoints may be changed in the future to take advantage of the more complete test date. l DCCUMENT ID 41181

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, LASALLE COUNTY STATION UNIT 2 TABLE 4 CORRECTIVE ACTICNS J

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

2. Flow testing to verify ECCS 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 D3cember 1986).

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 caitbration the switch will be cycled from the appropriate 0% or 100% of differential pressure span to the setpoint.

c. "As-found" setpoint acceptance ILuits will be included into the procedures, and actions will be defined for each limit. The limits and &ctions will be ,.

the following:

(1) Action Limit (a) Except Main Steam Line High Flow and ECCS minimum flow, i 3% of adjustable range from new -

calibration setpoint.

(b) For main steam line high flow and ECCS minimum flow, this limit was 1.5X repeatability of .f the most variable switch in service.

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

t (c) If this limit is exceeded, increase l surveillance frequencies for the switch. The next surveillance will be performed at the same interval as the last 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.

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

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this limit is (repeatability + tech.

spec. drift) for the most variable switch in service. Repeatability was calculated for each switch to 95% of the populatior. 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 l switches will remain on a quarterly j frequency. Note that this schedule assumes no problems occur with the limits as described above.

b. Main Steam Line Break Switches (16 switches) 1

- At least four of the main steam line (MSL) h switches will be calibrated 4 weeks after startup. Of the remaining 12 switches, at least four of the NSL 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 E after startup. The maximum interval for each individual switch will be limited to a quarterly frequency.

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• TABLE 4 (cont.)

LaSalle County Unit 2

c. Remaining switches (37 switches) - A sample I (grouped by model numbers) representative of the remaining switches (approximately 1/3) will be calibrated 4 weeks aftcr etertup, 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 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 Summary, dated 9/5/86 l

2. Unit 1 Plow testing to verify ECCS 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 i 3% of adjustable range from new calibration setpoint.

DOCUMENT ID 41181 1

TABLE 4 (cont.)

LaSalle County Unit 1

4. Complete calibration procedure revisions (cont.)

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

(b) For main steam line high flow l and ECCS minimum flow, this I limit was 1.5x repeatability of the most variable switch in service.

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 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.

(2) Rejection Limit (a) i (2% of adjustable range + tech, spec. margin for drift)

(b) For cain steam line high flow and ECCS minimum flow, switches l 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.

DOCUMENT ID 41181

e 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 mor.ths 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 l instruments to replace SOR l-1-87 l

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 l of key features affecting design installation,

! operation and maintenance, and project plan.

f. Initiate detailed conceptnal design.

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TABLE 4 (cont.)

LaSalle County Unit 1 The alternative options being considered at this time include:

a. Installation of improved design SOK 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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