ML20151C412

Rev 0 to Northern States Power Co Section V:Exercise Scenario,Part 1:Narrative Summary

ML20151C412
Person / Time
Site:	Prairie Island
Issue date:	07/12/1988
From:	NORTHERN STATES POWER CO.
To:
Shared Package
ML20151C337	List: IR 05000282/1988006 ML20151C333 ML20151C410 ML20151C412
References
NUDOCS 8807210350
Download: ML20151C412 (4)

Text

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PRAIRIE ISLAND NUCLEAR GENERATING PLANT l 4

EMERGENCY PLAN EXERCISE Rev. 0 1988 l

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NORTHERN STATES POWER COMPANY j SECTION V: EXERCISE SCENARIO PART 1: NARRATIVE

SUMMARY

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O PITC/EPLAN Page 1 of 4 SECTION V Part 1 l 8807210350 880712 PDR ADOCK 05000282 Q PDC ]

. G PRAIRIE ISLAND NUCLEAR GENERATING PLANT .

EMERGENCY PLAN EXERCISE Roy. 0 .

1988 TIME EVENT 0700 INITIAL CONDITIONS

1. Units 1 & 2 have been operating at 100% power for more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

2. 0.1 gpm leak on 1. . ?ince June 18.

3. Anticipate shutdown in about four hours.

4. VCT is at 85% for degas operations.

5. Unit 1 is at Middle of core life.

6. 12 Charging pump is 00S for cracked pump casing.

7. 13 Heater Drain Pump is 00S for PM.

8. 11 Safety Injection Pump is DOS due to leaking discharge flange. i l

9. Wind is from East Southeast (105') at 0.5 mph.

Temperature is 66'F.

0730 An element of the Reactor Coolant System (RCS) breaks loose causing a Digital Metal Impact Monitoring System (DMIMS) alarm and fuel damage. Some fuel damage occurs with channel blockage and localized overheating.

Auxiliary Building Operator reports the DMIMS alarm to the control room. 1 0745 The damaged fuel causes a rise in RCS activity which in turn causes the letdown radiation monitor R9 to alarm

(> 1R/Hr.).

The primary to secondary leak increases to approximately 75 gpm.

0800 An Alert is declared due to F3-2 Condition 2 and the plant begins an orderly shutdown.

0815 States and counties have been notified of Alert.

A steam generator tube rupture occurs. This initiates SI. 12 SI pump trips, 11 charging pump fails to minimum speed, 13 charging pump trips.

0830 Declare a Site Area Emergency due to F3-2 Condition 2.

Initiate a plant evacuation.

O PITC/EPLAN Page 2 of 4 SECTION V Part 1

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(IE. ISLAND NLCLEAR- GENERATING PLANT

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i* - EMERGENCY PLAN EXERCISE Rov 0 1988-TIME CONDITION 0900 TSC is fully operational.

1000 EOF is fully functional.

A steam line break occurs upstream of the MSlV.. PORV _

piping breaks on 4th floor. R22 and R50 alarm. A significant radioactive release to the environment is occurring.

1015 A General Emergency is declared based on Condition 6 Case 5.

1130 Plant is cooling towards shutdown.

1200 Exercise stops for 24-hour Time Step.

All EOCs review new conditions, emergency status, and odate status boards.

New Conditions: 1230 June 23, 1988

1. No significant radioactive release from site is occurring.

2. Affected unit is in cold shutdown condition.

O 3. Reactor is on RHR cooling and stable.

4. Broken steam line has been temporarily sealed.

5. Offsite ambient dose rates are t.ormal background.

The radioactive plume has dispersed.

6. The event classification was de-escalated to a Site Area Emergency at 0400 this morning, i 7. Offsite Protective Actions remain in effect.

1230 Restart of Exercise.

Coctrol Room and OSC personnel may terminate exercise involvement.

TSC and EOF discuss new conditions and Recovery efforts.

O PITC/EPLAN Page 3 of 4 SECTION V Part 1

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PRAIRIE ISLAND NUCLEAR GENERATING PLANT . .-

EMERGENCY PLAN EXERCISE Rev. 0

• 1988 TIME ,CONDITInN, )

1330 Full analysis of offsite radiological data complete.

NSP and States agree return / reentry of public is perm'is-sible. Protective Actions are cancelled.  !

. . . . try news briefings conducted at MN JPIC.

1430 All EOCs close out. Exercise is terminated.

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1 PITC/EPLAN Page 4 of 4 SECTION V Part 1 )