ML20064M554
| ML20064M554 | |
| Person / Time | |
|---|---|
| Site: | Clinch River |
| Issue date: | 02/14/1983 |
| From: | Longenecker J ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT |
| To: | Grace J Office of Nuclear Reactor Regulation |
| References | |
| HQ:S:83:221, NUDOCS 8302150576 | |
| Download: ML20064M554 (3) | |
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Department of Energy Washington, D.C. 20545 Docket No. 50-537 HQ:S:83:221 FEB 141983 Dr. J. Nelson Grace, Director CRBR Program Office Office of Nuclear Reactor Regulation U.S. Nuclear Regulat3ry Commission Washington, D.C.
20S55
Dear Dr. Grace:
ADDITIONAL'INFORMATION ON AUXILIARY FEEDWATER SYSTEM VALVES - CLINCH RIVER BREEDER REACTOR PLANT Enclosed are amended Preliminary Safety Analysis Report (PSAR) pages 5.6-8 and 13 that clarify the description of the auxiliary feedwater system valves as requested by the Nuclear Regulatory Consnission staff reviewer. These pages will be included in the next amendment to the PSAR.
Questions concerning the enclosure may be directed to Mr. D. Florek (FTS 626-6188) or Mr. D. Robinson (FTS 626-6098) of the Project Office Oak Ridge staff.
Sincerely.
O <r
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j John R. Longenecker Acting Director, Office of Breeder Demonstration Projects Office of Nuclear Energy 2 Enclosures cc: Service List Standard Distribution Licensing Distribution t
8302150576 830214 PDR ADOCK 05000537 A
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ENCLOSURE 1
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The pump discharge lines contain check valves to prevent back flow' through inoperable pumps. The motor driven pump discharge lines also contain a manually operated, locked open isolation valve downstream of the check valve. All three Class 3 discharge lines also have a 2 inch pump recirculation line containing an electrically-operated, normally closed Isolation valve, branching off and running back to the PWST.
e.
Auxillarv Feedwater Sunniv Lines The six auxiliary feedwater supply lines from both the turbine and motor driven pump discharge headers are 4 inch diameter and contain (in order and in direction of flow) a manually operated, locked open isolation valve; a normally open electro-hydraulic control valve; a normally closed, electric operated Isolation valve; and a manually operated, locked open Isolation valve. After the final isolation valve, the turbine and motor driven pump supply lines are joined. The resulting 4 inch carbon steel line, which contains two check valves and a manual isolation valve, is then routed to the steam drum.
Routing of the auxiliary feedwater supply lines is such that high pressure lines (high pressuring during normal plant operation) are not located in cells containing the PWST, auxillary feedwater pumps or other SGAHRS equipment whose f ailure could cause a loss of SGAHRS safety function.
f.
AFW Pumn Test Loon f
t Downstream of the tee where the motor-driven and turbine-driven pump supply lines join at the loop #1 valve station, an AFW pump test line returns flow to the protected water storage tank during periodic testing.
This line contains redundant automatic valves for Isolating the AFW supply from the PWST should SGAHRS be initiated during testing.
W g.
Steam Sucolv Line From Steam Drum to AEP Drive Turbine D
There are three 4 inch steam supply lines, one from each steam drum, ris#hgh of these lines contains a locked open, manual isolation valve, an l g)
_:?-'-y operated, normally closed Isolation valve, a check valve, and another locked open, manual isolation valve. Downstream of the final isolation valves, the three lines are headered together. The resultin 4 inch line then passes through a normally closed, electro-hydraulI perated pressure control valve before entering the drive turbine.
Routing of the turbine steam supply lines is such that they do not pass through the PWST cel1.
When the turbine Iines pass through adjacent cells, protection is provided from missiles and jet Impingement.
5.6-8 Amend. 65 Feb. 1982 4
ENCLOSURE 2
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Auxiliary Feedwater Supply Isolation Valve 49 l The electrically-operated valve in each of the six steam drum auxiliary feedwater supply lines is the only valve in the main flow paths of the SGAHRS that is normally closed during plant operation.
49 Inadvertant opening of this valve will not affect the operability of the 53AHRS or of the plant because redundant check valves will prevent reverse 17
- flow, Control Valve The electro-hydraulic operated control valve in each of the six steam drum auxiliary feedwater supply lines will fail "as is" upon loss of electrical power to the valve, thereby allowing feedwater supply to continue.
If a failure occurs in the control signal to the valve, and the valve opens to greater flow than required, the steam drum level in 17
.the affected loop could possibly rise to the trip level.
Closure of the motor driven and turbine driven auxiliary feedwater supply system isolation valves for the affected loop will be initiated by independent 43,
logic trains when the steam drum level rises to 8 and 12 inches above normal, respectively.
Auxiliary feedwater supply to that steam drum would be terminated until the level fell below the drum level setpoint.
The isolation valve would then open and flow would be supplied until reaching the trip point.
The sequence would then be repeated.
Heat
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58 1 removal capabilities would be available through all loops.
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58
,0 Drive Turbine Steam Supply Isolation Valve tieptYoh wma6 closcel isolation The e Ppglgperatedgalve in each of the three steam lines b 49l m
to the feedwatergggive turbine is in series with the_normalle ge closed pressure _.__, valve.
Inadvertent opening offt% valves will ;#
not have an adverse affect on the SGAHRS system or the rest of the plan.t.
Inadvertent closureYduring SGAHRS operation will have no effect due to 17 the redundant steam supplies from each drum.
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Amend. 58 5.6-13 Nov. 1980