TXX-4904, Forwards Addl Info Re Generic Ltr 85-12, Automatic Trip of Reactor Coolant Pumps, Per 860502 Request.Info Concerns Reactor Coolant Pump Trip Criteria,Potential Problems & Operator Training & Procedures
| ML20214V035 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 09/24/1986 |
| From: | Counsil W, Keeley G TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Noonan V NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM), Office of Nuclear Reactor Regulation |
| References | |
| GL-85-12, TXX-4904, NUDOCS 8610020101 | |
| Download: ML20214V035 (3) | |
Text
Log # TXX-4904 File # 10010 10035 c
TEXAS UTILITIES GENERATING COMPANY SKYWAY TOWER. 400 NORTH OLIVE FFREET, L.B. N1 DALLAN. TEXAS 75201 September 24, 1986 EMOAf?Jn'A Director of Nuclear Reactor Regulation Attention: Mr. Vince S. Noonan, Director Comanche Peak Project Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION DOCKET NOS. 50-445 AND 50-446 RESPONSE TO NRC QUESTIONS ON GENERIC LETTER 85-12 REF:
V. S. Noonan letter to W. G. Counsil dated May 2, 1986.
Dear Mr. Noonan:
The referenced letter requested additional information on NRC Generic Letter 85-12, " Automatic Trip of Reactor Coolant Pumps". ~ pecifically, Texas S
Utilities is to provide confirmation of the referenced letter's content, as well as supplemental information on three items.
The attachment to this letter provides the requested information.
Very truly yours, N
W W. G. Counsil X
By:
G~. S.' Keel ey Manager, Nuclear Li nsing RWH/gj Attachment pf googh p
p 3
A l)!YlM10N OF TEXAN UTil2TIEN ELECTRIC COMPANY
' Attachment to TXX-4904 NRC GENERIC LETTER 85-12 Response to NRC Letter dated May 2, 1986 A.
DETERMINATION OF REACTOR C0OLANT PUMP (RCP) TRIP CRITERIA A.1 Instrumentation used to determine the RCP trip set point:
Texas Utilities is in agreement with the NRC discussion on this item as presented in the May 2, 1986 letter.
l A.2 Instrumentation uncertainties for both normal and adverse containment conditions:
Texas Utilities is in agreement with the NRC discussion on this item as presented in the May 2, 1986 letter.
A trip setpoint calculation was performed by Texas Utilities. The results of the steam generator. transmitter evaluation are as follows. The minimum primary to secondary AP calculated to occur during a Steam Line Break / Feed Line Break (SLB/FLB) would be (811 psi - 125 psi =) 686 psi. The worst case primary side pressure error (normal conditions) would be 90 psi. The AP RCP trip setpoint is 164 psi. The worst case secondary side pressure error (adverse conditions) is considered proprietary by Westinghouse and is contained in Westinghouse letter WPT-7282. A SLB/FLB in the steam tunnel area is expected to result in a minimum AP indication (686 psi - (90 psi + worst case secondary side pressure error) =
minimum AP indication) that is greater than the AP setpoint.
i Therefore, these breaks should not result in a false indication requiring RCP trip. This is acceptable; there is no need to trip i
the RCPs in this scenario.
A.3 Uncertainties associated with the Westinghouse Owners Group (WOG) supplied analyses values:
Texas Utilities is in agreement with the NRC discussion on this item t
as presented in the May 2, 1986 letter.
l l
B.
POTENTIAL REACTOR COOLANT PUMP PROBLEMS j
B.1 Containment isolation for non-LOCA transients and accidents:
Texas Utilities is in agreement with the NRC discussion on the item 3
as presented in the May 2, 1986 letter.
B.2 Components and actions required to trip the RCPs:
i Texas Utilities is in agreement with the NRC discussion on this item as presented in the May 2, 1986 letter.
2 l
The CPSES Fire Protection analysis performed a timeline on tripping the RCPs locally. The travel time estimated to reach the RCP breaker panels is 2 to 3 minutes. Actual manual tripping of the i
l L
RCPs is accomplished by pushing the trip pushbutton located on the front of each of the breaker cubicles. The time required to trip all pumps is estimated to be 1 to 3 minutes (time line for tripping also includes pulling the control power fuses for :ach pump).
C.
OPERATOR TRAINING AND PROCEDURES (RCP TRIP)
C.1 Operator training program for RCP trip:
Texas Utilities is in agreement with the NRC discussion on this item as presented in the May 2, 1986 letter.
The conversion of the Westinghouse Owners Group (WOG) generic Emergency Response Guidelines (ERGS) to CPSES plant specific procedures as well as the criteria for operator training is detailed in the NRC approved Procedure Generation Package ODA-204, Preparation of ERGS. The development of plant specific procedures and operator training programs associated with RCP operation during accident conditions are based on information provided in the Executive Volume, RCP Trip / Restart pection of the ERG background documentatie developed by the WOG.1 This referenced document addresses th. NRC concerns related to RCP operation and has been submitted to the NRC by WOG letter 0G-123 dated May 4, 1984.
C.2 Procedures which include RCP trip related operations:
Texas Utilities is in agreement with the NRC discussion on this item as presented in the May 2, 1986 letter.
1 Background Information for Westinghouse Owners Group Emergency Response Guidelines, Generic Issue RCP Trip / Restart, Westinghouse Owners Group Executive Volume, HP/LP-Rev.1, September 1,1983.
1 1
1
. _ _ _ _ _ _ _ _. _,