ML20050B570
| ML20050B570 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 03/29/1982 |
| From: | Withers B PORTLAND GENERAL ELECTRIC CO. |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| TAC-46735, NUDOCS 8204060072 | |
| Download: ML20050B570 (6) | |
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- Elll PO.hGetieralBectricCoispmiy see Bs D. arm Vw Hwxre March 29, 1982 Trojan Nuclear Plant Docket 50-344 Gicense NPF-1 o/
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Director of Nuclear Reactor Regulation
/d ATTN:
Mr. Robert A. Clark, Chief g
Operating Reactors Branch No. 3 y
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$77 U. S. Nuclear Regulatory Commission q
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Dear Sir:
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Q Fire Protection By letters dated March 19, 1981 and May 5, 1981 PGE requested exemption from 10 CFR 50, Appendix R requirements for five areas of the Trojan Nuclear Plant. Based on discussions with members of the NRC staff during and subsequent to the NRC fire protection visit to Trojan on February 16, 1982, PCE is modifying and clarifying its exemption request to (1) pro-vide additional information as requested, (2) withdraw the exemption request for one area, and (3) request exemption for additonal areas.
I.
Additional Information Additional information is being provided for the five areas, as described below:
A.
Intake Structure (El 23 ft)
Alternate sources of water required for shutdown of the Plant are available in the event that a fire results in the loss of all three service water pumps.
As described in FSAR Sections 9.2.1.2.3.6 and 9.2.1.3, water can be supplied to the Service Water System from the Circulating Water System in the unlikely event of the unavailability of water from the Intake Structure.
An exemption from Section III.G.3 of Appendix R is
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still necessary since fixed fire suppression is not
/4 J installed in the room in the Intake Structure where the service water pumps are located.
/ O 8204060072 820329 PDR ADOCK 05000344 l
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PDR 121 S.W Sairnon Street, Por*.and Oregon 97204 t
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POrtialld Getieral Electric Cortyxuly Mr. Robert A. Clark March 29, 1982 Page two
'B.
Fuel Building (El 45 ft) 10 CFR 50 Appendix R requirements should not be applied to the component cooling water (CCW) makeup pumps (P-218A and B shown on Figure C of PGE-1012).
As described in FSAR Sections 9.2.2.2.1 and 9.2.2.2.3.5, the CCW system is a closed system with no part of the system being normally open to atmosphere. Periodic addition of water to the CCW system is required due to the normally small amount of leakage to be expected from the system (due to leakage from pump seals, valve packing, etc) and for the control of water chemistry for the prevention of long-term corrosion of the water passages in the CCW system. The volume of water in the CCN surge tanks (T-204A and B, capacity of 2000 gallons each) is adequate to cover small leakages that might occur during Plant shutdown.
Appendix R does not require the assumption of a pipe break in conjunction with the fire; nevertheless, should excessive leakage occur in the system, it will be detected by the CCW surge tank level indicators which will alarm in the control room. The system is design'I such that any point of leakage can be shut off and not affect the operation of the rest of the system, including the redundant CCW train. Therefare it can be concluded that the safe shutdown of the Plant can be achieved without use of the CCW makeup pumps. Please note, however, that an exemption from Appendix R requirements is still necessary for the 45-foot elevation of the Fuel Building since the CCW pumps (P-210A, B, and C) are also located in this area.
C.
Auxiliary Building (El 45 ft)
No additional information was required to be submitted.
D.
Turbine Building (El 45 ft)
The exemption request for this area is being deleted as discussed in Item II below.
l E.
Cable Penetration Area Outside Containment PGE will eliminate flammable gas cylinder storage located underneath cables in this area.
Portland General BectricCompany Mr. Robert A. Clark March 29, 1982 Page three II.
Exemption Request Withdrawal A.
Turbine Building (EL 45 ft)
PGE has concluded that an ex3mption for the Turbine Building (El 45 f t) area is not required. The area in question includes the diesel-driven auxiliary feedwater pump room, the auxiliary feedwater pump control panel room, and the area by the main feedwater pumps containing certain auto-start circuits for the safety-related auxiliary feedwater pumps. An exemp-tion request for the Turbine Building (El 45 f t) is not necesary for the following reasons:
(1) The diesel-driven auxiliary feedwater pump room is protected by fire detectors and an automatic fire suppression system. Figure F in Topical Report PGE-1012, " Trojan Nuclear Plant Fire Protection Review", shows an "A" train conduit leading to motor-operated valve MO-4907A and a "B" train conduit lead-ing to valve MO-4907B within this room.
However, these valves are on the fuel lines to the auxiliary feedwater pump diesel fuel oil day tank.
Loss of both cables would not adversely affect the redundant turbine-driven auxiliary feedwater pump.
(2) The auxiliary feedwater pump control panel room (shown in Figure F of PGE-1012 as the room con-taining the C-160 panel) is protected by fire detectors and an automatic fire suppression system inside the room and inside the panel itself. Therefore, the complete loss of this panel due to a fire is not credible.
In addi-tion, although such a fire would affect both the diesel-driven and the turbine-driven auxil-iary feedwater pumps, it would not affect the non-safety-related electric-driven auxiliary feedwater pump. The electric-driven auxiliary feedwater pump can provide the water needed for safe shutdown of the Plant, and it is separated from the auxiliary feedwater pump control panel room by a 3-hour fire barrier. This pump can also be powered from an emergency diesel gener-ator. A review of the flow path associated with the electric-driven auxiliary feedwater pump has
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Pbrttimd General Electric Cong)euly Mr. Robert.A.-Clark March 29, 1982 Page four indicated that control circuits for the auxiliary feedwater regulating valves (CV3004A1 through D1 and CV3004A2 through D2) also pass through the C-160 panel. These valves can be operated inde -
pendent of the. C-160 panel by manual trip of the breaker for each valve and manual handwheel operation, as necessary. Therefore, auxiliary feedwater can be provided in the unlikely event -
that a fire results in a complete loss of the j
auxiliary feedwater pump control panel (C-160).
I (3) The auto-start circuits shown in Figure G of i
PGE-1012 will start the safety-related auxil-iary feedwater pumps in the event that the -
main feedwater pumps trip off line. However, the safety-related auxiliary feedwater pumps are also started automatically upon receipt of a low-low steam generator level, safety injection, or loss-of-normal power signal.
Therefore, loss of both auto-start circuits 6
from the main feedwater pumps due to a fire in this area will not result in loss of the -
auxiliary feedwater system.
i Based on the above, PGE withdraws its ex eption request for the Turbine Building (El 45 f t).
III. Additional Exemption Requests i
A.
Main Control Room l
PGE has concluded.that an additional exemption from the requirements of Section III.G.3 of 10 CFR 50 Appendix R-to provide a fixed fire suppression system in the main control room is required. This exemption is hereby requested and is based on the 'following:
(1) Shutdown capability is available remote from the control room. A discussion of this capa-bility begins on Page'C-16 of PGE-1012 (please note, however, that although not all of the decouple switches listed in PGE-1012 were installed, safe shutdown capability was installed for one train of components).
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Portland General BectricCorry)any Mr. Robert A. Clark March 29, 1982 Page five (2) A fire detection system has been installed in the control room.
(3) Manual fire extinguishers are available inside the main control room, and manual hose stations are located just outside the main control room.
(4) The main control room is continually manned by the operators.
Items 1) and 2) above satisfy the requirements that are specified in Section III.C.3 of Appendix R, except for the fixed fire suppression system.
Since the operators provide, in effect, a continuous fire watch, manual fire suppression will be prompt and effective in the event that a fire does occur. Therefore, a fixed fire suppres-sion system in the main control room is not necessary since an equivalent degree of protection is available.
A similar exemption for the cable spreading room (CSR) is not necessary.
Fire detection and a fixed fire sup-pression system are installed in the CSR and the safe shutdown capability mentioned above provides alternate shutdown capability in the event of a fire in the CSR.
Therefore, the requirements that are specified in Section III.C.3 of Appendix R are satisfied for the CSR.
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B.
Manholes NM-3 and NM-4 PGE has concluded that an exemption from the requirements of Appendix R Section III.G.3 is necessary for manholes NM-3 and NM-4 since both trains A and B power cables for the service water pumps (P-108A, B, and C) are routed l
through these manholes.
l Although these cables are wrapped with asbestos tape and are protected by a noncombustible radiant energy shield (1/2 in. marinite board as described on page B-84 of PGE-1012), fire detectors and fixed fire suppression systems are not installed in the manholes as required by Apprendix R.
As discussed in Item I.A above and on page B-84 of PCE-1012, the Circulating Water System is
Pbetterid M Bechich Mr. Robert A. Clark March 29, 1982 Page__six available as a water source in the event that water from the Intake Structure is unavailable due to the loss of all three service water pumps.
Sincerely, 1
L
': 1 Bart D. Withers Vice President Nuclear c:
Mr. Lynn Frank, Director State of Oregon Department of Energy 4
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