ML20214S232
| ML20214S232 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/23/1986 |
| From: | Allen C COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 2144K, IEB-86-002, IEB-86-2, NUDOCS 8609290426 | |
| Download: ML20214S232 (2) | |
Text
s p
} CoWNRonwealth FAleon One First Nabonal Plaza, Ch caGo, Mnois c/ Address Reply to: Post Omco Box 767 b/ Chicago, Mnois 60600 - 0767 September 23, 1986 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
LaSalle County Station Unit 1 Information Regarding Differential Pressure Switches NRC Docket No. 50-373 References (a): Letter dated Setpember 16, 1986 from A. B.
Davis to Cordell Reed.
(b): Telecon conducted on Spetember 18, 1986 between Commonwealth Edison and NRC Staff.
Dear Mr. Denton:
Per commitments made in References (a) and (b), attached is the data from the atmospheric pressure level drop test made on LSCS Unit 1.
The first data taken September 9, 1986, was committed to in Reference (a) and j
was taken prior to Unit I startup. The second data was taken after a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> soak following the 50% Rod Density Scram as committed to in Reference (b).
Test Procedure LST-86-207 was conducted to evaluate the operability of the scram function at the Level 3 setpoint determined as a result of the i
SOR Setpoint Characterization Test Program. The SOR Differential Pressure Switches serving the Low Level Scram and ADS Permissive functions had been calibrated to trip on decreasing level at 19.4" RWL.
The Reactor Water Level wss lowered by blowing down the vessel to the condenser through the Reactor Water Cleanup System. It was expected that all six switches would trip at a value of 19.4" RWL i [2.6" RWL (Repeatability) + 1.5" RWL (Tech.
Spec. Instrument Drift)] or, between 15.3" RWL and 23.5" RWL.
These values had been determined from the SOR Differential Pressure Switch Setpoint Characterization Testing Program and presented in Table 3 of the Cortmonwealth Edison supplemental response to I.E.Bulletin 86-02 dated September 8, 1986.
a 8609290426 860923 I
hDR ADOCK 05000373 PDR
Mr. H. R. Denton September 23, 1986 The actual results of the Level Drop Tests were as follows:
Switch Tag No.
Function Measured Trip Point * (" RWL) 09/09/86 09/20/86 LS-1B21-N024A SCRAM Channel Al 19.8 18.4 LS-1B21-N024B SCRAM Channel B1 18.9 17.9 LS-1B21-N024C SCRAM Channel A2 19.3 18.4 LS-1B21-N024D SCRAM Channel B2 19.6 18.1 LS-1B21-N038A ADS Permissive 19.7 19.2 LS-1B21-N038B ADS Permissive 18.7 18.4
- These values were as measured from the Level Transmitter on the same instrument rack as each switch, sharing the same sensing lines. A member of the Region III I&E Staff was present during the testing. The results of the test showed that the conclusions reached in the Setpoint Characterization Program have been supported.
If you or your staff have any additional questions regarding this matter, please address ther to this office.
trulyyo#urs, d4Vera C. M. Allen Nuclear Licensing Administrator 1m Attachment cc:
R. Bernero - Region III Dr. A. Bournia - NRR Region III Inspector - LSCS i
l 2144K