Outline of Joyo restoration work
Transcript of Outline of Joyo restoration work
Outline of Joyo restoration work
Experimental Fast Reactor Joyo
Oarai R&D Center, JAEA
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Outline of Joyo
restoration work
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Background
Hold
down
shaft
Lower part of UCS
Fiber
scope
Bent irradiation
test S/A
(MARICO-2) Top of S/As
MARICO-2 : Material
testing rig with
temperature control
IVS : In-vessel storage
rack
IVS
The top of irradiation
test subassembly
(S/A) “MARICO-2” had
bent onto the IVS.
“MARICO-2” had
damaged the upper
core structure (UCS).
This incident requires replacement of UCS and retrieval of
MARICO-2 S/A for Joyo re-start 3
Cask
(2) Retrieval of
ed-UCS
Door valve
(3) Retrieval of
MARICO-2 S/A
(4) Installation of
n-UCS
L-R/P
S-R/P Temporary pit cover
Screw jack-up equipment
Guide tube
(1) Jack-up of
ed-UCS
UCS
Cask
MARICO-2
S/A
MARICO-2 S/A retrieval equipment
Wire jack-up equipment
Ed-UCS is extracted through
small-diameter part.
UCS
Outline of restoration work plan
Plant condition :
- Fuel S/As are remained in reactor vessel.
>>> Sodium level is maintained at 50 mm below top of fuel S/A.
- Temperature of sodium is approximately 200deg-C, and temperature of
cover gas is approximately 140~160deg-C.
ed-UCS : existing damaged UCS
n-UCS : new UCS
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Joyo restoration work plan
2011 2012 2013 2014 2015
Manufacturing of new UCS
Full ex-vessel test
Manufacturing of MARICO-2 subassembly retrieval equipment
Replacement of UCS
Retrieval of MARICO-2 subassembly
Ex-vessel test of jack-up equipment
Manufacturing of jack-up equipment
Manufacturing of cask, door-valve etc.
Full ex-vessel test
Detaching of equipment on R/P Re-installation of equipment on R/P
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On-site preparation work
for Joyo restoration
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1. Arrangement of R/P position
> Large R/P : 254deg.
> Small R/P : 115deg.
2. Detaching of equipment on R/P
(jacked-down at position as mentioned above)
3. Others
> Reactor is shut down
- Control rod : Inserted into core
- Control rod driving mechanism : Detached for maintenance
> As fuel S/As are remained in reactor vessel, primary sodium
coolant retained in reactor vessel.
* Sodium level is maintained GL-9540 (50 mm below top of fuel
S/A) ~ GL-6100 (normal level) as required in maintenance.
* To avoid contact, ed-UCS cannot be set just
above MARICO-2 S/A.
( Retrieval is performed using hole through
which ed-UCS is extracted )
On-site preparation work
for Joyo restoration Large R/P
Small R/P
MARICO-2 S/A
UCS
Location of R/P
during restoration work
Retrieval
equipment
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Ex. : Detaching of equipment on R/P
Upper : Door-valve on fuel handling hole
Lower : Hold-down shaft driving mechanism
UCS
[ Objectives of detaching of equipment on R/P ]
> To secure area for UCS removal and installation
(Detaching door-valve on fuel handling hole / hold-down shaft driving
mechanism / door-valve on inspection hole (A) )
> To secure working area (Detaching surrounded equipment)
Temporary cover
Door-valve on
inspection hole (A)
Before After
Temporary door-valve
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Ref. Structure of R/V, R/P and UCS
Small R/P
Large R/P
UCS
Core
R/V
R/V
inlet
R/V
outlet
IVS
Inspection hole (B)
Fuel handling hole
Inspection hole (A)
One center hole
and ten control rod holes
Control rod
upper guide tube
Thermo-couple
sleeves
Sodium flow
regulating grid
Control rod 9