ML20199E929
| ML20199E929 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/22/1998 |
| From: | NORTHEAST NUCLEAR ENERGY CO. |
| To: | |
| Shared Package | |
| ML20199E925 | List: |
| References | |
| NUDOCS 9802030008 | |
| Download: ML20199E929 (5) | |
Text
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Docket No. 50-423 B16954 l
Attachment 2 Millstone Nuclear Power Station, Unit No. 3 Marked Up Technical Specification Peges
_ January 1998 -
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9902030008 990122 PDR P ADOCK 05000423 pg
Pr.sca NA .5~37-97 3/4.5 EMERGENCY CORE COOLING SYSTEMS . JAN 31 1986
,8ASES 3/4.5.1 ACCUMULATORS The OPERABILITY of each Reactor Coolant' System (RCS) accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the
_ core provides the initial cooling mechanism during large RCS pipe ruptures.
" The limits on accumulator volume, boron concentration pnd pressure ensure that the assumptions used for accumulator injection in the safety analysis are met. pptkr Mre"MscMA * -g ~___'
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":p;r: tin; byp:::::" ir th: : = tet Of IEET Etd. 279-1971, 9 5:5 :q :: th:t byp::::: Of :etpr t::thtfun:ti=
rtMn addition, as Er re;=f these c:ti;;11yisolation accumulator trgs valves 2:r':'.r Qefitte: tr:
fail to meev, single failure criterie, removal of power to the valves is required.
The limits for operation with an accumulator inoperable for any reason
' except an isolation valve closed minimizes the time exposure of the plant to a LOCA event occurring concurrent with failure of an additional accumulator which may result in unacceptable peak cladding temperatures. If a closed isolation salve cannot be immediately opened, the full capability of one accumulator is not available and 1rompt action is required to place the reactor in a mode where this capasility is not required.
3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS The OPERABILITY of two independent ECCS subsystems ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of one subsystem through any single failure consideration.
Either subsystem operating in conjunction with the accumulators is capable of supplying sufficitnt core cooling to limit the peak cladding temperatures within acceptable limits for all postulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward. In addition, each ECCS subsystem provides long-term core cooling capability in the recirculation mode during the accident recovery period.
With the RCS temperature below 350'F, one OPERABLE ECCS subsystem is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and t'. limited core cooling requirements.
- h Ver.T J F.e t.;. 9 c _
' *' 6E_ ..C r a f-Jy-O MILLS 103 - UNIT 3 B 3/4 5-1 cSM
t Insert A 4
The accumulator power o)erated isolation valves are required to meet the '
guidance of " operating sypasses" in the context of IEEE Std. 279-1971, which requires that bypasses of a protective function be removed automatically whenever permissive conditions are not met. The "oparating bypass" designed for the isolation valves is applicable to Modes 1, 2, and 3 with Pressurizer pressure above P-ll setpoint.
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Docket No. 50-423 B16954 l'
l l
l Attachment 3 Millstone Nuclear Power Station, Unit No. 3 Retyped Technical Specification Pages January 1998
,o 3/4.5 EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.1 ACCUMULAT3RS The OPERABILITY of each Reactor Coolant System (RCS) accumulator ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the accumulators. This initial surge of water into the l core provides the initial cooling mechanism during large RCS pipe ruptures. l The limits on accumulator volume, boron concentration and pressure ensure that the assumptions used for accumulator injection in the safety analysis are met.
The accumulator power operatnd isolation valves are required to meet the guidance of "o)erating bypasses" in the context of IEEE Std. 279-1971, which requires that )ypasses of a protective function be removed automatically whenever permissive conditions are not met. The " operating bypass" designe<i for the isolation valves is applicable to Modes 1, 2, and 3 with Pressurizer pressure above P-ll setpoint, in addition, as these accumulator isolation valves fail to meet single failure criteria, removal of power to the valves is required.
The limits for operation with an accumulator inoperable for any reason except an isolation valve closed minimizes the time exposure of the plant to a LOCA event occurring concurrent with failure of an additional accumulator which may result in unacceptable peak cladding temperatures, if a closed isolation valve cannot be immediately opened, the full capability of one accumulator is not available and prompt action is required to place the reactor in a mode where this capability is not required.
3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS The OPERABILITY of two independent ECCS subsystems ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of one subsystem through any single failure consideration.
Either subsystem operating in conjunction with the accumulators is capable of sup)1ying sufficient core cooling to limit the peak cladding temperatures wit 11n acceptable limits for all postulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward. In addition, each ECCS subsystem providts long-term core cooling capability in the recirculation mode during the accident recovery period.
With the RfS temper m re below 350*F, cne OPERABLE ECCS subsystem is acceptable without singi L lure consideration on the basis of the stable reactivity condition of t e ceactor and the limited core cooling requirements.
MILLSTONE - UNIT 3 B 3/4 5-1 Amendment No.
0506