ML20042C571
| ML20042C571 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 03/23/1982 |
| From: | Vandewalle D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Hind J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8203310536 | |
| Download: ML20042C571 (5) | |
Text
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OPOW8r C0HSum8IS o,,w., v m n.
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PRINCIFA,, STAFF DIR AWM&IS General Offices: 1945 West Parnali Road, Jackson, MI 49201 e (517) 788-1636 D
m March 23, 1982 A/D S_f. O OR&?T DE&TI g
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J A Hind, Director m
D Division of Emergency Preparedness o\\
and Operational Support x
q Region III
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US Nuclear Regulatory Commission f/
Y/pD 799 Roosevelt Road Q
Glen Ellyn, IL 60137 DOCKET 50-155 - LICENSE DPR 'y BIG ROCK POINT PLANT - EMERGENCY g
PLAN EXERCISE SCENARIO t
In response to NRC Region III letter dated March 3, 1982, the attached exer-cise scenario is provided. The conduct of the Big Rock Point Plant Emergency Plan Exercise is scheduled for April 6, 1982 as specified by our letter of March 12, 1982.
It should be noted that the attached scenario is not considered a credible sequence of events. The scenario was developed as such to exercise all four phases of the Emergency Plan.
It reflects as much as possible, realistic situations however, it is Consumers Power Company's position that any credible accident scenario would not exercise the four phases specified as Unusual Event, Alert Status, Site Emergency and General Emergency.
Limited distribution of the attachment to this letter is requested to only those persons acting as observers until completion of the exercise.
Copies of this letter without attachment have been distributed internally to those Consumers Power Company personnel responsible for implementation of the Site Emergency Plan.
oc0382-0032a142 MAR 2 5g 8203310536 820323 PDR ADOCK 05000155 s
F PDR j
l J A Hind, Director 2
Big Rock Point Plant Emergency Plan Exercise Scenario March 23, 1982 1
Analysis of the specific time sequences for each event are currently under development.
These times will be added to the date/ time column of the attach-ment and will be provided to NRC staff observers upon request.
OM David VandeWalle Nuclear Licensing Administrator CC J G Keppler, Administrator, Region III Director, Office of Nuclear Reactor Regulation Director, Office of Inspection and Enforcement NRC Resident Inspector-Big Rock Point a
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SCENARIO BIG ROCK POINT EMERGENCY EXERCISE nu0382-0032bl42 o
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E SCENARIO BIG ROCK POINT EMERGENCY EXERCISE Date/ Time Events 3
April 5 Failure of Electric Fire Pump to start during monthly surveillance test.
April 6 Fire pump still under repair precipitating an UNUSUAL EVENT resulting in a plant shutdown as a result of non-availability of fire pump.
April 6 Turbine rupture diaphragm blows.
Produces following sequence of events:
a.
steam release (puff) to turbine building b.
turbine trip c.
closure of valves to turbine and condenser d.
reactor trip e.
closure of containment exhaust and supply valves Above sequences result in change to ALERT status and activation or TSC and OSC.
(Note: Valve i
position indication shows valves to be closed, however it is assumed for scenario purposes that valves did not seat properly.)
April 6 Due to increasing reactor pressure, the open setpoint of the emergency condenser valves is reached.
It is assumed that the valves fail to open.
April 6 Steam drum safety relief valve opens as set-
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point is reached. Valve modulates controlling pressure about the open setpoint.
April 6 It is assumed that one of the steam drum safety relief valves sticks open. As a result the steam drum level falls to 17 inches below centerline.
i Because of containment pressure, containment isola-tion occurs.
Steam drum level requires operation of fire pump. Diesel pump fails to start.
April 6 Vessel water level decreases to 2 feet 9 inches above core. Reactor Depressurization System fails to actuate due to low fire system header pressure. Core spray valves open at 200 lbs pressure, but there is no core spray flow due to.
i inoperability of' fire pumps. These conditions r
indicate an escalation through SITE EMERGENCY and a declaration of GENERAL EMERGENCY.
(No protective actions for public.)
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le D;te/ Time Evants April 6 Vessel water level downscale.
Core partially uncovered gap release to containment. Stack gas monitor indicates release is occurring. Protective action for public recommended.)
April 6 Maintenance team repairs diesel fire pump. RDS and core spray flow established. Reactor vessel level rises due to feedwater and core spray to above 2 feet 9 inches.
Containment spray initiates.
April 6 Steam drum level recovered.
April 6 Vacuum relief required as a result of containment spray. Containment exhaust valves open. Stack gas monitor indicates release terminated because containment is no longer pressurized.
April 6 Vacuum relief complete. Vent valves closed.
Reactor in cold shutdown. Monitoring teams from plant and State verify releases have terminated.
April 8 For scenario purposes, a time advance occurs, the (Simulated) governor, in conjunction with appropriate federal authorities, declares general emergency classifi-cation over and the recovery /re-entry phase of this exercise begins.
Apri18 Exercise terminates.
(Simulated)
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