DOE 2000. - Waste Isolation Pilot Plant - U.S. Department of Energy

WIPP RH PSAR DOE/WIPP-03-3174 CHAPTER 5
C
C
C
C
C
Mission time for waste hoist is 1000 hours/yr (i.e, 7,000 round trips per yr) which includes
transfers of RH and CH waste to the Underground
Maximum test time for standby components is 24 hours
Waste hoist is operated in automatic mode only when transferring RH waste because manual
mode is not modeled in the fault tree analysis
Waste hoist system is subjected to a series of thorough "pre-operational check" test at the start
of each eight hour shift. Operation of the waste hoist system does not begin until the tests are
successfully completed. In the fault tree analysis this test interval is conservatively assumed to
be three times greater or 24 hours.
If the hoist system is to be operated more than one shift per day, or there is a change of
operator, the hoist system will be removed from service and the same "pre-operational check"
test will be performed
The defense-in-depth SSCs which are applicable to this scenario, per the criteria provided in Chapter 3,
Section 3.1.3 are assigned as follows:
C
Vented DOT Type A (or equivalent) waste canister - Primary confinement
C
C
C
C
C
Underground Ventilation Exhaust System - Secondary confinement
Radiation Monitoring System (active waste disposal room exit alpha CAM for underground
shift to filtration) - Secondary confinement
Underground Ventilation Exhaust HEPA Filters - Secondary confinement
Central Monitoring System (for actuation of underground shift to filtration only) - Secondary
confinement
Design of facility cask - Prevents/minimizes releases from the waste canister
The defense-in-depth ACs which are applicable to this scenario, per the criteria in Chapter 3, Section
3.1.3 are assigned as follows:
C
The door to the waste hoist is not opened until the conveyance is locked in position and the
pivot rails are in place - Prevents the drop of the facility cask into the shaft
Section 5.2.4.1, Evaluation of the Design Basis, discusses in greater detail: (1) the evaluation of safety
SSCs, and (2) the applicability of functional and performance requirements (system evaluation) and
controls (TSRs). Detailed design descriptions for the above defense-in-depth SSCs may be found in
Chapter 4 and the applicable SDDs.
Due to the importance of WIPP programs relating to configuration and document control, quality
assurance, conduct of operations, preventative maintenance and inspection, waste handling procedures
and training, the WIPP RH WAC, and the WIPP Emergency Management Program 36 and associated
procedures, in the WIPP defense-in-depth strategy for this accident, TSR ACs are derived in Chapter 6
and required in the WIPP TSR Document.
5.2-34 January 22, 2003