TXX-4528, Clarifies Re Operator Action for Control Room/Cable Spreading Room Fire,In Response to NRC Question 010.32.Response Will Be Included in Future Amend to FSAR
| ML20134A788 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/06/1985 |
| From: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Noonan V NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM) |
| References | |
| TXX-4528, NUDOCS 8508150419 | |
| Download: ML20134A788 (3) | |
Text
- yu o-m Log # TXX-4528 File # 10010 TEXAS UTILITIES GENERATING COMPANY 909.5 MKYWAY TOWEH
- 400 NONTH OLIVE MTHEET, L.H. ML
- DALLAN, TEXAM 73201 August 6, 1985 2U^LLca?."3 Director of Nuclear Reactor Regulation Attention: Mr. Vincent 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 OPERATOR ACTION FOR CONTROL ROOM /
CABLE SPREADING ROOM FIRE
Dear Mr. Noonan:
'In accordance with recent discussions between our staffs, this letter provides clarification to Texas Utilities letter TXX-4478 dated May 21, 1985 as follows:
1.
Attached is an amended response to NRC Question 010.32. This response will be included in a future amendment to the FSAR.
2.
The referenced letter provided marked up copies of the CPSES Fire Protection Program Review (FPPR) delineating specific operator actions (and times for each action) required for safe shutdown _during a Control Room / Cable Spreading Room fire. The NRC staff requested that we verify that the plant can be safely shutdown without operator action outside the Control Room for ten minutes.
We have reviewed the time requirements for operator actions outside of the Control Room. Actions required to preclude the possibility of spurious activations are initiated as rapidly as possible. Any other actions can be delayed for ten minutes without adversely affecting safe shutdown with the exception of the activities required to restore UPS room ventilation. For a Control Room / Cable Spreading Room fire concurrent with a loss of offsite power, operator actions to restore ventilation are currently required in less than ten minutes.
Should you have any questions in this matter, please contact this office.
l Very truly yours, j
fiftsk l
W. G. Counsil 9
1 0,CP BSD/grr V
h Attachment i nurs sox or ruxA~ erus.orsen us.ucense counxv
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c c.c CPSES/FSAR Q010.32 In the response to 010.26, the applicant identified the following high to low pressure interfaces that require post fire operator actions to prevent overpressurizing the systems:
a.
Pressurizer Power-Operated Relief Valves b.
Normal Letdown Isolation Valves c.
Excess Letdown Isolation Valves d.
Reactor Head and Pressurizer Vent Valves In order to complete our evaluation, we require a description of the post fire operator actions that include the priority of the operator actions, the number of actions, and the time allowed for each action.
In addition, verify that these operator actions are listed in the safe shutdown procedures.
R010.32 CPSES Safe Shutdown systems are designed to preclude spurious operation of high-to-low pressure interface valves. Operator action to prevent these spurious operations is only required for Cable Spreading Room / Control Room fire scenarios and is described below.
Table 4-1.4 of the CPSES Fire Protection Program Review (FPPR) provides a summary of operator actions required at the Hot Shutdown Panel (HSP). To prevent spurious operation of the Train B Pressurizer Power Operated Relief Valve,1-PCV-456, and the Excess Letdown Isolation Valve, 1-8153, the operator, at the HSP, connects the alternate power supply path to these valves by transferring control to the Hot Shutdown Panel. This transfer is accomplished by changing the position of a series of switches on the HSP.
CPSES/FSAR Table 4-1.3 of the FPPR proviaes a summary of operator actions required at the Shutdcwn Transfer Panel (STP). To prevent spurious operation cf the Train A Pressurizer Power Operated Relief Valve, 1-PCV-455A, and the Normal Letdown Isolation Valves,1-8149A,1-8149B and 1-8149C, the operator, at the STP, connects ina alternate power supply path to these valves by transferring control to the Hot Shutdown Panel.
Priority of operator actions and the time allowed for each operator action are given in FPPR Figures 4-2 and 4-1, respectively.
FPPR Table 4-1.1 provides a summary of operator actions required at various locations throughout the plant. To prevent spurious operation of the Reactor Head and Pressurizer Vent Valves, 1-HV-3607, 1-HV-3608, 1-HV-3609 and 1-HV-3610 respectively, the operator disconnects DC power at the 125V DC switchboard in the DC Inverter Equipment Room, by turning off the DC input to the respective distribution panels.
FPPR Figure 4-3 indicates the priority of these actions and the time allowed.
All operator actions are listed in detail in CPSES procedure ABN 803A, " Response to a Fire Affecting Control Room or Cable Spreading Room".
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