PSA of Accidents in the Spent Fuel Pool - EDF Hinkley Point

HPC-NNBOSL-U0-000-RES-000034 Version 2.0
PSA of Accidents in the Spent Fuel Pool
NOT PROTECTIVELY MARKED
4.4.4.8.2 Fuel Damage
The following table lists the main Spent Fuel Pool accident sequences due to accidents
leading to fuel damage, in all reactor states. They represent around 75% of the overall
risk of fuel damage in the Spent Fuel Pool (for non draining events).
Initiating Event Description Freq.
(/r.y)
%
Long Loss of Offsite
Power in state AB
(including consequential
LOOP)
Loss of Offsite Power in
Refuelling state
Long Loss of Offsite
Power in state AB
(including consequential
LOOP)
Loss of Offsite Power in
Refuelling state
Loss of Cooling Chain in
state AB
Loss of Cooling Chain in
Refuelling state
Loss of Offsite Power in
Refuelling state
Loss of PTR [FPCS]
pump in state AB
Loss of Cooling Chain in
state AB
Failure of fuel pool cooling due to failure of
emergency electrical supply and/or preventative
maintenance and failure of makeup using backup
equipment and failure to repair the failed
components before 107h.
Failure of the SPPA-T2000 platform and the
operator fails to carry out a local action to initiate
the stand-by pump before 97°C and failure of
makeup using backup equipment and failure to
repair the failed components before 33 hours.
Failure of the SPPA-T2000 platform and the
operator fails to carry out a local action to initiate
the stand-by pump before 97°C and failure of
makeup using backup equipment and failure to
repair the failed components before 107 hours.
Failure of fuel pool cooling due to failure of
emergency electrical supply and/or preventative
maintenance and failure of makeup using backup
equipment and failure to repair the failed
components before 33 hours.
Failure of the SPPA-T2000 platform and the
operator fails to carry out a local action to initiate
the stand-by pump before 97°C and the operator
fails to initiate makeup of the fuel pool and failure
to repair the failed components before 107 hours.
Failure of the third PTR [FPCS] train (cooling
chain or intrinsic) and failure of the operator to
initiate the makeup equipment and failure to repair
failed components before 33 hours.
Failure of the operator to initiate the stand-by
pump before 97°C and failure of makeup using
backup equipment and failure to repair the failed
components before 33 hours.
Failure of the SPPA-T2000 platform and the
operator fails to carry out a local action to initiate
the stand-by pump before 97°C and the operator
fails to initiate makeup of the fuel pool and failure
to repair the failed components before 107 hours.
Failure of the SPPA-T2000 platform and the
operator fails the local action to initiate the standby
pump before 97°C and failure of makeup of
the fuel pool due to failure of normal and backup
equipment and failure to repair the failed
components before 107 hours.
1.00E-10 18.9
9.66E-11 18.2
5.62E-11 10.6
5.22E-11 9.8
3.06E-11 5.8
2.15E-11 4.0
1,93E-11 3.6
1.07E-11 2.0
9.2E-12 1.7
UNCONTROLLED WHEN PRINTED
NOT PROTECTIVELY MARKED
Page 24 of 37