ML20072P505

Forwards Monticello Nuclear Generating Plant Emergency Plan Evaluation Exercise Scenario,830223. Document Developed W/Input from Involved State Agencies

ML20072P505
Person / Time
Site:	Monticello
Issue date:	01/14/1983
From:	Ward E NORTHERN STATES POWER CO.
To:	Patterson J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 8304040288
Download: ML20072P505 (3)

Text

__,

m 2MB.

Uniif Northem States Power Company 414 Nicollet Mall Minneapohs, Minnesota 55401 Telephone (612) 330-5500 L PRif1CIPAL STAFF January 14, 1983  ;> A g 0/kA wp Regional Administrator LOQ_ .

p g.p p W~]

[7,. q]l Region III v J EP!;o s: Tg7 U S Nuclear Regulatory Commission [EWP]

799 Roosevelt Road ML p , ,

Glen Ellyn, IL 60137 Attn: J P Patterson CL l FILE $/Q/

%Y D MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50-263 License No. DPR-22 Emergency Plan Exercise - February 23, 1983 Responsive to your January 12, 1982 guidance letter we are furnishing the attached scenario outline (dated 1/12/82) for the subject exercise.

The document has been developed with input from the involved State agencies.

Copies of this document are being forwarded to FEMA by the Minnesota Division of Emergency Services (MDES).

E C Ward PE Manager-Nuclear Environmental Services ECW/js cc: Thomas P Motherway, Director MDES w/o attachment Brian K Grimes, U S NRC-Division of Emergency Preparedness j l

i l

l l

8304040280 830114 N PDR ADOCK 05000263 F PDR

.gg

. MONTICELLO NUCLEAR GENERATING PLANT Jrnuary 12, 1983

• s EMERGENCY PLAN EVALATION EXERCISE FEBRUARY 23, 1983 Exercise Scenario 0730 Initial Conditions Monticello Nuclear Generating Plant is operating at full power.

All identified leakages = 0.75 sps and unidentified leakages = 0.5 spa.

Wind is out of the SSW (202*) at 5 mph and temperature is 26*F.

0800 'A significant leak of 60 gym is indicated in the D y ell Floordrain Sumn.

The reactor should be scrammed by the operators. The #12 Reactor Feed Pump is taken off as part of normal scram procedures.

An ALERT should be declared by the Shift Supervisor and the proper notifications and activation of the emergency organization be performed.

0830 The Drywell pressure 2 2 psig.

The ECCS is initiated but due to the unexpected lockout of BUS #16 and Bus

1. 14, the #12 CRD Pump, #12 Core Spray Pump, #12 and #14 LPCI Pumps, and #12 Condensate Pumps are lost.

0900 A Design Basis Accident LOCA occurs. Leak rate increases beyond core make up capacity. The Reactor Vessel level drops below Top of Active Fuel (-114 inches).

A SITE AREA EMERGENCY should be declared.

The Reactor Vessel depressurizes to Drywell Pressure which peaks at about 36 psig.

HPCI and RCIC isolate on low static pressure.

Core Spray Pump #11 trips.

The #11 Reactor Feed Pump trips because #11 Condensate pump trips.

0930 Reactor Vessel Level increased to 1/3 core height.

Drywell pressure has decreased to 25 psig.

1000 A release to the environment is indicated by the Stack Gas Monitors via failed open drywell vent valves through the SBGT system. The Stack Gas Monitors indicate a release rate of about 2E9 pCi/sec.

A GENERAL EMERGENCY should be declared based on the indicated release rate.

MA111682B01 Page 1 of 2

,, MONTICELLO NUCLEAR GENERATING PLANT Jrnuary 12, 1983

- N' EMERGENCY PLAN EVALATION EXERCISE FEBRUARY 23, 1983 1030 The #11 Core Spray pump is restored.

1100 One of the two failed Drywell Vent Valves has been closed. As a result, the

, radioactive release to the environment has been terminated.

I 1130 The #11 Condensate Pump is restored to service.

1150 The emergency may be downgraded to a SITE AREA EMERGENCY once the surrounding area dose rates allow.

1200 The exercise will be terminated with all onsite plant participants with possible exception of the radiation protection group and TSC supervision.

All offsite emergency organizations will continue with the exercise.

(

1200/

1230 Lunch Break for exercise participants.

1230 BRIEFING FOR 2-DAY TIME ADVANCE

1. Update of Plant Parameters / Conditions and Environmental Parameters:

• Plant is at Cold Shutdown

• TLD Point results in the affected sectors

• Ground surface contamination data

• First milk samples results

• Ambient y levels

• The plant is at the ALERT LEVEL

• Public remains evacuated from the affected sectors.

&E r ave > 1.<t 1300 Wie DAY ADVANCE - Begin Real Time 1300 F.esdey, February 25, 1983

%= W yjN' Mw-State survey teams and NSP EREMP personnel are sampling the environment (snow, milk, feed, ambient y levels).

State labs are reporting the analysis of snow, milk, and feed samples that were received from the morning.

The #11 RHR pump fails due to seizure. Operations Committee convenes to l discuss repair plans.

1400 Environmental sample analysis show no food contamination. The ground contami-nation <0.13pci/m2 Iodine - 131. The emergency level should deescalated to the NUE level. It is anticipated that the public will be allowed to reenter the affected sectors.

1500 Final news releases issued and close out of JPIC.

Close out of all other Emergency Operating Centers.

MA111682B01 Page 2 of 2

. - _ . . - - _ . --- - . ~ . .- .- - - - . - - - .