ML20083A084
| ML20083A084 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/03/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20083A085 | List: |
| References | |
| NUDOCS 9505090305 | |
| Download: ML20083A084 (1) | |
Text
_
(l.
,f REFUELING 0PERATIONS maert 3/4.9.10 and 3/4.9.11 WATER LEVEL - REACTOR VESSEL and STORAGE POOL The restrictions on minimum water level ensure that sufficient water depth is available to remove 99% of the assumed 10% iodine gap activity released from the rupture of an irradiated fuel assembly.
The minimum water depth is consistent with the assumptions of the safety analysis.
1 3/4.9.12 FUEL BUILDING EXHAUST FILTER SYSTEM The limitations on the Fuel Building Exhaust Filter System ensure that all radioactive iodine released from an irradiated fuel assembly and storage pool water j
will be filtered through the HEPA filters and charcoal adsorber prior to discharge to the atmosphere. Operation of the system with the heaters operating for at least 10 continuous hours in a 31-day period is sufficient to reduce the buildup of moisture on the adsorbers and HEPA filters.
The OPERABILITY of this system
)
and the resulting iodine removal capacity are consistent with the assumptions of the safety analyses.
ANSI N510-1980 will be used as a procedural guide for surveillance testing. The filtration system removes radiciodine following a fuel handing or heavy load drop accident. Noble gases would not be removed by the system.
Other radionuclides would be scrubbed by the storage pool water.
Iodine-131 has the longest half-life:
-8 days.
After 60 days decay time, there is essentially negligible iodine and filtration is unnecessary.,
3/4.9.13 SPENT FUEL POOL - REACTIVITY The limitations described by Figure 3.9-1 ensure that the reactivity of fuel assemblies introduced into Region II are conservatively within the assumptions of the safety analysis.
Administrative controls have been developed and instituted to verify that the enrichment and burn-up limits of Figure 3.9-1 have been maintained for the fuel assembly.
3/4.9.14 SPENT FUEL POOL - STORAGE PATTERN The limitations of this specification ensure that the reactivity conditions of the Region I storage racks and spent fuel pool k,,, will remain less than or equal to 0.95.
The Cell Blocking Devices in the 4th location of the Region I storage racks are designed to prevent inadvertent placement and/or storage of fuel assemblies in the blocked locations. The blocked location remains empty to provide the flux trap to maintain reactivity control for fuel assemblies in adjacent and diagonal locations of the STORAGE PATTERN.
STORAGE PATTERN for the Region I storage racks will be established. and expanded from the walls of the spent fuel pool per Figure 3.9-2 to ensure definition and control of the Region I/ Region II boundary and minimize the number of boundaries where a fuel misplacement incident can occur.
NILLSTONE - UNIT 3 B 3/4 9-8 Amendment No. 77, 177 m
107 i
9505090305 950303 i
PDR ADOCK 05000423 P
POR
.