ML20210A935
| ML20210A935 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 05/01/1987 |
| From: | Cockfield D PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| TAC-65306, NUDOCS 8705050196 | |
| Download: ML20210A935 (3) | |
Text
,
a M
M M
N Gerieral ElectricCorigxityf David W Cockfield %co President, Nuclear May 1, 1987 Trojan Nucicar plant Dockot 50-344 Licenno NpF-1 U.S. Nucicar Regulatory Commloolon ATTN: Document Control Dock Wachlngton DC 20555 Door Slet TROJAN NUCLEAR PLANT Circulatijir. Water Slalem Doolrn Crltoria pursuant to discupolona with Mr. T. L. Chan of your staff, attached for your information lo an advanco copy of our propocod revision to the Final Safety Analyolo Report (FDAR) Section 10.4.6.3 concerning flooding annock-nted with a postulated failuro in the Circulating Water System. Thlo propocod c.hango will be made to the FSAR in accordance with Title 10. Code of Federal Regulations, part 50.71(c) on or about July 1, 1987.
The pur-poco of thlo revision to to clarify the procent doolen critoria of the Circulating Water Syntom.
Ao reported in Liconoco Event Report 87-06 dated Apell 8, 1987, it was dotormined that the an-built condition of the Turbino Building would not have provided auffielent flow rollof in the event of a break of the Circu-lating Water System. At a flood flow rate of 500,000 spm, the louvoro installed in the lower 3 f t of tho Turblno Building wallo would not have provented water lovolo from excooding the 41-ft levol olovation and pocolng over the flood-protection d1kon. The declan critoria of 500,000 gpm duo to the full-diamotor brook of an expanaton joint to conaldorod concorvativo, pcx plano to submit additional information in the futuro to chango thin critoria.
Interim correctivo action to being taken to ralco the levol of tho diken protectinr,cafoty-rotated equipmont in the Turbino Hullding from an olovation of 47 ft to an olovation of 48 ft until auch timo no chanson to the circulatinr, Water System failuro critoria can bo submitted to and approved by the NRC.
An analyals hun shown that tho 1.ft incroano in holeht provideo suffielent margin to protect tho cofoty-rolated equipmont on Elevation 45 f t of the Turblno Bullding; thoro lo no cafety rotated equipment below tho 45-ft clovation in tho Turbino Dullding. Thlo 0705050196 070501 Uvk PDR ADOCK 05000344 a
P PDR
.m_.__
W M BeddCC0fMM1y Document Control Desk May 1, 1987 page 2 increased height of the barriers protecting this equipment will be accomplished prior to startup from the current refueling shutdown.
Additionally, the louvers that had been installed in the Turbine Building walls will not be reinstalled. On a temporary basis, the lower 2 ft 6 in.
of the Turbine Building will remain open; subsequently, modifications will be made to allow passage of water resulting from a failure in the Circulating Water System in the Turbine Building.
Should you have any further questions or desire additional information, please do not hesitate to contact us.
Sincerely, t
(
Attachment et Mr. John B. Martin Regional Administrator, Region V U.S. Nuclear Regulatory Comission Mr. David Xish, Director State of Oregon Department of Energy Mr. H. C. Barr NHC Resident Inspector Trojan Nuclear plant
e The possibility of flooding of the ESF equipment (emergency diesel gen-erators and auxiliary feodwater pumps) located on the Turbino Building floor at Elevation 45 ft as a result of a failure in the Circulating Water System was considered in the design of the Turbino Building. All operating parts of the ESF equipment are protected against flooding up to h
Elevation 48 ft.
A full-dlamotor break in an expansion joint in one loop of the Circulating Water System, almultaneous with failure to close of the motor-operated valvos at the auction and dischargo of the circulating water pumps, would cause flow of water from the cooling tower basin into the Turbino Building not excooding a maximum rate of 500,000 spm. This analysis assumes no loss of offsito power and no stopping of the circulating water pumps.
Openings are provided in the walls of the Turbino Building at Elevation
]
45 ft. The openings have sufficient area to discharge water outsido of the building at a rato of 500,000 spm and koop the water lovel below Elevation 48 ft in the Turbino Building, h
The potential for damago to other plant structures in the event of collapse of the cooling tower is ovaluated in Section 2.2.3.7.
10.4.6.4 Tosts and Inspoettonn A shop test was performed on a homologous model pump in accordance with the Ilydraulle Instituto Standards. The performance was found to bo satisfactory in this test. The hydraulic performanco of the cooling tower makeup pumps and the Turbino Building cooling water boostor pumps was tooted in accordance with standards of the ifydraulle Institute and was found to meet the specified performanco requirements. The system was touted in accordance with written proceduros during the initial testing and operation program.
10,.a_4.6.5 -((1simmorit allpjl_hpplLqatiof1 Indicating lights are provided in the control room to indicato open and closed pooltions of motor-operated butterfly valvon in the circulat-j ing water piping. The motor-operated valvoo at the circulating, water Am n n 6 10.4-23 (July 1987)
-.