ML19332C542
| ML19332C542 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 11/20/1989 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-88-17, TXX-89804, NUDOCS 8911280245 | |
| Download: ML19332C542 (3) | |
Text
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Log # TXX 89804 i
File # 10035 i
C C
905.4 filELECTRIC Ref. # 10CrR50.34(b)
November 20, 1989 wimum J. cehm. Jr.
Executtw Yur besuirnt i
U. S. Nuclear Regulatory Commission Attr.: Document Control Desk Washington. D.C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) 4 DOCKET NOS. 50-445 AND 50-446 UPDATED RESPONSE TO GENERIC LETTER 88 17 REF:
TU Electric letter TXX 89041 from William J. Cchill, Jr. to the U.S.N.R.C. dated February 10. 1989 Gentlemen:
l The referenced letter provided the CPSES response to Generic letter 88-17.
As stated in the letter. TV Electric committed tn performing a vortex test to, in t
part, determine reliable indications of Residual Heat Removal (RHR) system air entrainment. The results of the vortex test have been evaluated and changes to the monitoring system have been identified. The following information provides a complete description of the capability.for monitoring RHR system performance, including any changes or additions resulting from the vortex test.
The vortex test was conducted to develop a CPSES specific relationship between RHR water level and maximum Reactor Coolant System (RCS) flow, compare the response of various level indications, and determine the most reliable-indicationc of RHR system air entrainment.
Indications monitored during the testing included:
Standpipe level at the high pressure side of the new narrow range level transmitter Loop 4 crossover leg tygon tube level Visus 1 level inside the active hot leg RHR suction source Ultrasonic level in the active and non-active hot leg RHR suction source RHR flow (control board indication and local high accuracy differential pressure cell)
RHR pump motor current RHR pump suction pressure using Heise gauge Local pump noise 8911280245 891120
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.PDR ADOCK 05000445
- A PDC l
l 400 North Olive Street L B. 81 Dallas. Texas 75201
v TXX-89804 November 20, 1989 Page 2 of 3 Based on the observations of the vortex test, it was determined that the following supplements to the existing RHR system instrumentation would provide an enhanced monitoring capability for the RHR system:
1.
Improve existing control board indication for RHR flow channels to increase resolution at low flow rates, 2.
Add control room indication of RHR pump suction pressure including an audible alarm for abnormal conditions.
3.
Add control room indication of RHR pump motor current, including an audible alarm for abnormal conditions.
Although current fluctuations were not noted during vortex testing, this has historically been a reliable indicator of excessive air entrainment and impending pump damage.
These changes / additions to the RHR system instrumentation augment the existing RHR system instrumentation which includes:
Control board indication of pump discharge pressure Control board indication of pump flow Local indication of pump suction pressure Local indication of pump miniflow Local indication of pump motor current at 6.9ky switchgear Design modifications to implement these items for Unit I will be completed prior to the end of the first refueling outage for Unit 1.
Unit 2 design modifications will be complete prior to Unit 2 fuel load.
Sincerely.
/l
,_y William J. Cahill, Jr.
JDS/gj c
Mr. R. D. Martin, Region IV l
Resident Inspectors, CPSES (3) j i
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TXX-89804 November 20, 1989
[
Page 3 of 3 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
)
)
Texas Utilities Electric Company
)
Docket Nos. 50-445
)
50 446 (Comanche Peak Steam Electric
)
Station. Units 1 & 2)
)
AFFIDAVIT William J. Cahill, Jr. being duly sworn, hereby deposes and says that he is Executive Vice President. Nuclear of TV Electric, the lead Applicant herein:
that he is duly authorized to sign and file with the Nuclear Regulatory Commission this update to Generic Letter 88 17: that he is familiar with the content thereof and that the matters set forth therein are true and correct to the best of his knowledge, information and belief.
&~ /
William J. Cahi1 R Jr.
Executive Vice President. Nuclear STATE OF TEXAS
)
COUNTY OF a.Ab Subscribec} and sworn to before me, a Notary Public on this e86d day of 91ow-vrt4w
. 1989.
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Nofary Public