ML20024G779
| ML20024G779 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 04/24/1991 |
| From: | Cross J PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20024G780 | List: |
| References | |
| NUDOCS 9104300294 | |
| Download: ML20024G779 (2) | |
Text
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James E. Cross Vice President, Nuclear April 24, 1991 Trojan Nuclear Plant Docket 50-344 License NPF-1 U.S. Nuclear Regulatory Commission Attn Document Control Dock Washington DC 20555
Dear Sirs:
Change to Trojan Technical Specification (TTS) Bases 3/4.7.6. " Control Room Vontilation System" Portland Conocal Electric Company has changed the Technical Specification Bases for Facility Operating Licenso NPF-1 to clarify the operability requirements for the Control Room Emergency Vontilation System with regard to service water for cooling of the Control Room. A deucelption of the change as well as the coacons and justification for the change and replacement pages are attached.
Sincoroly.
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Mr. John B. Martin Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. David Stewart-Smith Stato of Oregon Department of Energy Mr. R. C. Barr NRC Resident Inspector Trojan Nuclear Plant
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o Trojan Nuclear Plant Document Control Desk Docket 50 344 April 24 1991 License NPF-1 Attachment Page 1 of 2 Reason for Chance This change was initiated to clarify the operability requirements of the Control Room Emergency Ventilation System (CREVS). The CREVS consists of the subsystems CB 1 and CB 16.
Among its functions, the CREVS provides post accident cooling to the Control Room.
This change adds clarification to the Technical Specification Bases of 3/4.7.6 that Service Water is not necessary for the operability of the CREVS, This clarification will allow removing the Service Water System from service without declaring the CREVS inoperable and entering the action statements for Limiting Condition for Operation (LCO) 3.7.6.1.
A second minor clarification is made to the wording in the third paragraph of the Bases for 3/4.7.6.
The existing wording defines recirculation, To be in recirculation, the Bases state that the system must be capable of responding to a safoty injection signal. This clarification adds wording to indicate that the system does not have to be capabic of responding to a safety injection signal when in an operational mude which does not require safety injection.
Justification for Changg The CB 16 subsystem does not use Service Water for cooling. Section 9.4 of the Trojan FSAR indicates that CB-16 has the capacity to handle the cooling requirements of the control room, whether operating alone or in conjunction with CB 1.
Der,crintion of Chance The following paragraph is added after the first paragraph of the Bases for 3/4.7.6:
The cooling function of the control room emergency ventilation system can be performed by the CB-16 subsystem alone.
CB 16 does not use the service water system for cooling. As a consequence, the loss of service water to CB 1 does not result in the inoperability of the control room emergency ventilation system.
In addition, the phrase "(when in a MODE where safety injection is required)" is added in the third paragraph af ter the words ".. capable of responding to a safety inj ection signal,"
These changes are shown on the following page.