ML20236K722
| ML20236K722 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 07/07/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20236K724 | List: |
| References | |
| NUDOCS 9807100055 | |
| Download: ML20236K722 (1) | |
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1 The low 'evel water level trip setting of 11'5" above the top of the active fuel has been established to
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assure that the reactor is not operated at a water level below that for which the fuel cladding integrity l
safety limit is applicabic. With the scram set at this point, the generation of steam, and thus the less of inventory is stopped. For example, for a loss of feedwater flow a reactor scram at the value indicated and isolation valve closure at the low-low water level set point results in more than 4 feet of water remaining above the core after isolation (6).
During periods when the reactor is shut down, decay heat is present and adequate water level must be maintained to provide core cooling. Thus, the low-low level trip point of 7'2" above the core is provided to actuate the core spray system (when the core spray system is required as identified in Section 3.4) to provide cooling water should the level drop to this point.*
The turbine stop valve (s) scram is provided to anticipate the pressure, neutron flux, and heat flux increase caused by the rapid closure of the turbine stop valve (s) and failure of the turbine bypass system.
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The generator load rejection scram is provided to anticipate the rapid increase in pressure and neutron f
flux resulting from fast closure of the turbine control valves to a load rejection and failure of the turbine bypass system. This scram is initiated by the loss of turbine acceleration relay oil pressure, i
The timing for this scram is alnest identical to the turbine trip.
j The undervoltage protection system is a 2 out of 3 coincident logic relay system designated to shift emergency buses C and D to on-site power should normal power be lost or degraded to an nw~ptable level. The trip points and time delay settings have been selected to assure an n+qn*
power source to emergency safeguards systems in the event of a total ins of normal power or
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degraded conditions which would adversely affect the functioning of eng,imered safety features connected to the plant emergency power distribution system.
4 References (1)
FDSAR, Volume 1, Section VII-4.2.4.2 (2)
FDSAR, Awndment 28, Item III.A-12 (3)
FDSAR, Awndmant 32, Question 13 (4) 1.etters, Peter A. Morris, Director, Division of Reaction Licensing, USAEC, to John E.
I.ogan, Vice President, Jersey Central Power and Light Company (5)
FDSAR, Amendment 65, Section B.XI (6)'
FDSAR, Amendment 65, Section B.IX OYSTER CREEK 2-3.7 Amendment No.-W6.195 i
- Correction 11/30/87 9907100055 990707 7
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