ML20207C679
| ML20207C679 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 12/24/1986 |
| From: | Lindblad W PORTLAND GENERAL ELECTRIC CO. |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-3.D.3.4, TASK-TM TAC-61289, NUDOCS 8612300208 | |
| Download: ML20207C679 (2) | |
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a PORTLAND GENERAL ELecrRic COMPANY l2l S.W. S ALM ON STREET WI LLI A M 'J. LIN C B LAD PORTLA N D. OR EGON 97204 lsos) aze-se7s
. December 24, 1986 Trojan Nuclear Plant Docket 50-344 License NPF-1 Director of Nuclear Reactor Regulation ATTN:
Nr. Steven A. Varga Director, PWR-A Project Directorate No. 3 U.S. Nuclear Regulatory Conunission Washington DC 20555
Dear Sir:
References:
'1) PCE (Withers) to NRC (Varga) Letter, Regarding EUREG-0737 III.D.3.4, Control Room Habitability, September 30, 1986'.
- 2) PGE (Withers) to NRC (Varga) Letter, License Change Application 142, September 30, 1986.
Control Room Habitability Reference 1 provided our plan and schedule for implementing control room habitability design changes. One of the planned design changes is to improve control room cooling and is sunmarized below for your. information.
Engineering has been initiated to install two or three fan-coil units which will serve the control room. Each fan-coil unit will be connected to either a separate roof-mounted air-cooled water chiller or refrigeration unit. These units will be designed to meet Seismic category I requirements.
The units will be capable of being manually loaded onto the emergency diesel generators. These units will supplement the existing control room emergency ventilation system (CB-1) and will provide a level of cooling to the control room comparable to the normal ventilation system (CB-2).
Out-5 side air makeup and filtration will continue to be provided by CB-1.
Technical Specifications governing these new coolers will be proposed when I
the system becomes operational.
It. is planned to have these new fan-coil units operational no later than the end of the 1988 refueling outage.
l In addition, a thorough control room temperature survey is undentay.
The survey consists of locating therrocouples throughout the control room i
j cabinets. Temperatures are being recorded during operation of both the normal and emergency ventilation systems. This data will be used in Identifying which cabinets are experiencing high temperatures.
If Il 8612300208 861224 I
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PORTLAND GENERAL ELECTRIC COMPANY Mr. Steven A.' Varga December.24, 1986 Page 2 necessary, to improve ventilation in these cabinets, " knock-outs" will be removed and/or local ventilation fans will be added.
While these efforts will significantly improve control room ventilation, the long lead-time for procuring new equipment precludes the installation of the new room coolers by the summer of 1987. As you are aware, it is during the warm sunner months while testing CB-1 in accordance with Tech-nical Specification 4.7.6.1.a that heat-up problems are experienced.
Control room instrumentation is subjected to higher-than-normal tempera-tures and appears to undergo accelerated aging with each test of CB-1 during the warm summer months. This accelerated degradation of instru-mentation may increase the likelihood of equipment failure which in turn could increase the possibility of an' inadvertent Plant shutdown during testing of CB-1.
Instrumentation failures have occurred during CB-1 testing this past summer.
Therefore, in light of the design changes and testing connitted to above, it is requested that you expedite your review and approval of the CB-1 testing changes requested in Reference 2.
This combination of reduced testing frequency and control room cooling enhancements will optimize control room habitability.
Sincerely, p,
c:
Mr. David Kish, Acting Director State of Oregon Department of Energy i