ML20198H778
| ML20198H778 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 01/28/1986 |
| From: | NIAGARA MOHAWK POWER CORP. |
| To: | |
| Shared Package | |
| ML17055B191 | List: |
| References | |
| NUDOCS 8601310094 | |
| Download: ML20198H778 (4) | |
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ATTACHMENT A NIAGARA M0 HAWK POWER CORPORATION LICENSE NO. DPR-63
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DOCKET NO. 50-220 Proposed Changes to Technical Specifications (Appendix A)
Existing page 47 will be replaced with the attached revised page.
This page has been retyped in its entirety with marginal markings to indicate changes to the text.
I 0601310094 D60128 DR ADOCK 000 0
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LIMITING CONDITION FOR OPERATICN SURVEILLANCE REQUIREMENT 3.1.3 EMERGENCY, COOLING SYSTEM 4.1.3 EMERGENCY _ COOL _ING SYSTEM Applicability:
Applicability:
Applies to the operating status of the Applies to periodic testing requirements emergency cooling system.
for the emergency cooling system.
Objective:
Objective:
To assure the capability of the emergency To assure the capability of the cooling system to cool the reactor coolant in emergency cooling system for cooling of the event the normal reactor heat sink is not the reactor coolant.
available.
Specification:
Specification:
The emergency cooling system a.
During power operating conditions and surveitlance shall be performed as t.henever the reactor coolant temperature indicated below:
is greater than 212*F except for hydrostatic testing with the reactor not a.
At least.pnce evely_five_ years -
critical, both emergency cooling systems shall be operable except as specified in The system heat removal capability 3.1.3.b and c.
sha'l be determined.
b.
During the remainder of Cycle 8 with one b.
At least once daily -
emergency cooling system inoperable, Specification 3.1.3a shall be considered The shell side water level and fulfilled, provided the additional makeup tank water level shall be suiveillance required in 4.1.3.f is checked.
performed.
c.
At least once per month -
c.
During Cycle 9 and subsequent cycles, if one emergency cooling system becomes The makeup tank level control valve inoperable, Specification 3.1.3.a shall shall be manually opened and closed.
be considered fulfilled, provided that the looperable system is returned to an operable condition within 7 days and the additional surveillance required in 4.1.3.f is performed.
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'I' ATTACHMENT B NIAGARA M0 HAWK POWER CORPORATION LICENSE DPR-63 DOCKET NO. 50-220 Supporting Information Hydrostatic test temperatures and pressures are governed by the requirements of Technical Specification 3.2.2.
The pressure temperature limits set forth therein are periodically revised based on measured nil-ductility temperature shifts of irradiated vessel material samples.
Recent revisions to these pressure / temperature limits will result in minimum temperatures for pressurization in excess of 2120F.
The Emergency Cooling System is normally an integral part of the hydrostatic test performed at Nine Mile Point Unit 1.
During the test the Emergency Cooling System steam supply piping and emergency condenser tube bundles are filled with water.
In this condition, the Emergency Cooling System is not available to perform its intended function.
Therefore, the requirements for Emergency Cooling System operability when the reactor coolant is greater than 2120F is requested to be modified to exempt this requirement during hydrostatic testing with the reactor not critical.
10CFR50.91 requires that at the time a licensee requests an amendment, it must provide to the Commission its analysis, using the standards in Secti:n 50.92, about the issue of no significant hazards consideration.
Therefore, in accordance with 10CFR50.91 and 10CFR50.92, the following analysis has been performed:
The proposed amendment in accordance with the operation of Nine Mile _ Point uni ^t 1 will not involve a sigt.ificant increase in the proDubility or consequences of an accident previously evaluated.
The Emergency Cooling System is a standby high pressure system designed to act as a redundant backup to the main station condenser for rece'iving reactor core decay heat following reactor vessel isolation and scram.
In addition, for small line breaks, the Emergency Cooling System assists the Automatic Depressurization System (ADS) in depressurizing the reactor vessel.
The mergency Cooling System is not intended to mitigate the affects of initial pressure peaks resulting from various transients such as turbine trip, or main steam line isolation valve closure, but rather longer term decay heat removal.
The Emergency Cooling System consists of two independent loops each designed to remove decay heat at a rate of approximately three percent of maximum reactor steam flow.
This capacity is sufficient to handle the decay heat production at 100 seconds following SCRA".
Each loop consists of a 12-inch steam supply header, two parallel condensers, a 10-inch concensate return line, two steam supply isolation valves and one condensate return isolation valve, separate shell steam vents and ssparate instrumentation and control.
n ATTACHMENT 8 (cont'd)
The Emergency Cooling. System is designed such that operation is maintained by natural circulation.
Steam flows from the reactor vessel to the condensers where it is condensed.
The condensate returns by gravity to the suction side of a reactor recirculation loop where it is returned to the reactor vessel.
The configuration of Nine Mile Point Unit 1 for the hydrostatic test conditions differs from normal operation. Control rods are fully inserted and water level is outside its normal band.
Pressurization is controlled utilizing the control rod drive system and/or hydrostatic test pump while temperature changes are affected utilizing the reactor recirculation system and/or other supplemental heat sources. Also, the reactor coolant system, with the exception of the Emergency Cooling System, is isolated.
In this configuration, the capability of the Emergency Condenser System to remove decay heat following reactor isolation or to assist in reactor depressurization for small line break is not required.
Therefore, the proposed amendment will not invoke a significant increase in the probability of consequences of an accident previously evaluated.
The proposed amendment in accordance with the operation of Nine Mile Point Unit I will not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed amendment eliminates the requirement for Emergency Condenser System operability with reactor coolant temperature greater than 2120F during hydrostatic testing with the reactor not critical. The Emergency Cooling System is normally included in hydrostatic testing of the reactor coolant system. With its steam supply lines full of water, the system is not available nor necessary to perform its designed function.
A break in the Emergency Condenser System under hydrostatic conditions is enveloped by a similar break under normal operating conditions. Also, transients, which operation of the Emergency Cooling System would mitigate, are not feasible to occur due to the plant configuration existing during hydrostatic testing.
The proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed amendment in accordance with the operation of Nine Mile Point Unit I will not involve a significant reduction in a margin of safety.
Implementation of the proposed change will have no effect on the availability of the Emergency Cooling System for those plant operating conditions where it is required to mitigate the effects of operational transients.
Excluding the operability of the Emergency Cooling System during hydrostatic testing of the reactor coolant system with the reactor not critical will not result in a reduction in the margin of safety.
As determined by the analysis above, this proposed amendment involves no significant hazards consideration.
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