ML19270H521
| ML19270H521 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/04/1974 |
| From: | Bernero R, Schwencer A US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML19210B193 | List: |
| References | |
| NUDOCS 7911040125 | |
| Download: ML19270H521 (2) | |
Text
..
g)*MR,
).$
UNITED STATES fi ) d [ 3 ATOMIC ENERGY COMMISSION J
j' wasmuoron, o.c. zos4s ss
~
5 SAFETY EVALUATION BY THE DIRECTORATE OF LICENSING SUPPORTING A'!ENDME:iT N0. 2 TO LICE:ISE N0. Dr. 50 (Change No. 2 to Appendix A of Technical Specifications)
METROPOLITAN EDISON COMPA'iY JERSEY CE:ITRAL FOUER AND LIGHT COMPANY PE:CiSYLVANIA ELECTRIC COMPANY THREE MILE ISLA'!D Sl* CLEAR STATION - UNIT 1 DOCKET NO. 50-289 Introduction By letter d::ted June 3, 1974, Metropolitan Edison Company (Meted) requested a change to the Technical Specifications appended to Facility Operating License No. DPR-50 fo; the Three Mile Island Nuclear Station -
Unit 1 (TMI-1). The proposed c hange would temporarily permit plant warmup and low power (less thea 5% of rated power) operation while any one of the emergency feedwater (ETW) pumps is out of ccamission. The Teciudcol 3pecificativus, appenuix 4,
section 3.*,
present2y rcquire at least one of the motor-driven EFW pumps and the turbine-driven EFW pump to be in service before the plant is heated to more than 250'F.
Discussion The EFW Systen in TMI-l is designed to provide cooling water to the steam generators for the removal of reactor decay heat in the event the main feedwater system fails, and in spite of potential single active failures of ccaponents in the EFW and related systems. The EFW system design is based on a decay heat load equal to about 5% of rated reactor power, using one, full-capacity (920 gpm), turbine-driven pump and tuo, half-capacity (460 gpm), electric motor-driven pumps. The turbine-driven pump is served by control pouer from both emergency busses; the motor-driven pumps are normally aligned one on each emergency bus.
- Thus, with the common feedwater header to the steam generators, any pair selected from these three pumps provides redundant emergency feedwater capability up to half of the design decay heat load. Beyond that all three pumps are needed since both half-size motor-driven pumps are needed to be redundant to the full-size turbine-driven pump.
The possible decay heat load in the plant is limited by the peak pover at which the plant has operated. Thus, if the plant is never permitted to operate above 50% of rated power, the decay heat load will never be 97[}
X /s )
e s v 79110@ @ '
. dated : Lay 10, 1974. All of these are available for public inspection at the Co= mission's Public Document Room, 1717 H Street, N.
W.,
Washington, D. C., and at the Government Publication Section, State Library of Pennsylvania, Box 1601 (Education Building), Harrisburg, Pennsylvania.
A copy of items (2), (3) and (4) may be obtained upon request addressed to the United States Atomic Energy Commission, Washington, D. C.
20545, Attention: Deputy Director for Reactor Projects, Directorate of Licensing - Regulation.
Dated at Bethesda, Maryland, this 4 day of v'U.
1974.
FOR THE ATOMIC ENERGY C0:! MISSION "aIJuaI5Isacd2sy m
3.Macacer A. Schwencer, Chief Light Water Reactors Branch 2-3 Directorate of Licensing g_
s,
/
v 9