ML20064G388
| ML20064G388 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 12/29/1982 |
| From: | Larson C NORTHERN STATES POWER CO. |
| To: | Hind J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8301110465 | |
| Download: ML20064G388 (4) | |
Text
Nb Northern States Power Company I
414 Nellet Mall Minneapolis, Minnesota 55401 Telephone (612) 33o-5500 December 29, 1982
/
Mr. J. A. Hind, Director Division of Emergency Preparedness and Operational Support Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
Dear Mr. Hind:
PRAIRIE ISLAND NUCLEAR GENERATING PLANT DOCKET NOS. 50-282 LICENSE NOS. DPR-42 50-306 DPR-60 Your letter of December 2nd, transmitting Inspection Reports 50-282/82-18 and 50-306/82-18, requested that we submit a written statement describing our planned actions for improving the two items identified in the letter Appendix.
Following is our response:
Weakness Based on plant data including containment pressure, two out of four containment fan coils being inoperable, one out of two containment spray pumps inoperable, both diesel generators out of service, high radiation levels in containment and primary coolant activity greater than 300 pCi/cc, a General Emergency should have been declared at 11:00 A.M.
Instead a General Emergency was not declared until 11:30 A.M.
Thus, by the earlier General Emergency declaration, more time would have been available to notify State and Local governmental agencies who in turn could have begun evacuation and/or sheltering of the general public, earlier than actually occurred during scenario conditions.
PI122782RLA01 8301110465 021229 PDR ADOCK 05000282 gg 3 1[0 3 O
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Mr. J. A, Hind-December 29, 1982 Page 2
-Response At-11:00 A.M., two of the three fission product barriers were breached. The minimum required containment suppression equipment (2 out of 4 Fan Coil Units and 1 out of 2 spray pumps) were operating to provide sufficient cooling to reduce containment pressure during the Design Basis Accident, as specified in the Technical Specifications. With this suppression equipment in service, containment pressure was trending down and had already declined 10 psi (from 40 to 30 psig).
Loss of the third or potential loss of the chird fission product s
barrier was not immediately evident at 11:00 a.m., as was a deliberate scenario development. The scenario allowed for escalation to a General Emergency at 11:30 A.M. to allow State & Local Authorities sufficient time in the Site Area Emergency classification in order for them to adequately demonstrate various capabilities.
At 11:00 A.M., the Control Room received indication, via the Control Room Controller, that the Containment Purge Valve Close Light
(#44104B9) went out.
It is felt that the Technical Support Center (TSC) personnel did not hesitate, at this time, to escalate to a General Emergency, but that they were attempting to substantiate the validity of the release path potential as indicated by the loss of the Purge Valve Damper Close Light. The Purge Valve Damper Close Light going out was not adequate and should not be adequate indication to predict actual or potential release paths without backup indication. Verification of a release should have been indicated by loss of the Purge Valve Damper Light in conjunction with an onscale indication from the Shield Butiding Stack High Range Monitor, IR-50. The Shield Building stack low range monitor, at this time, was pegged high due to elevated background radiation levels.
When the Radiation Emerger:cy Coordinator (REC) requested 1R-50 readings, he was instructed that IR-50 was' erratic. The scenario contained both a table of the radiation monitor readings, which listed 1R-50 simply as erratic, and also radiation monitor graphs, which depicted 1R-50 bouncing erratically at a high level.
If the REC had been given the range of the erratic readings, as depicted on the 1R-50 graph versus the word erratic from the radiation monitor table, the REC would have immediately recommended to the Emergency Director that a General Emergency be declared. However, since the REC, at this point, had no concept as to what IR-50 was actually doing, an inplant survey team was dispatched to investigate the erratic response of 1R-50 (still with no indication of range from the controller).
When confirmation of the release was received, the TSC personnel recommended escalation to a General Emergency at 11:21 A.M.; however, the lead controller held off the notification until 11:30 A.M. for the benefit of State and Local Authorities.
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Mr. J. A. Hind' December 29, 1982 Page 3 The emergency classification procedure, F3-2, and the scenario have been reviewed.
The following changes are recommended:
(1) The loss of 2 of 3 fission product barrier Emergency Action Level (EAL) should be changed to include other key parameters as indicators for loss of the third fission product barrier rather than simply loss of the minimum required pressure suppression equipment.
(2) The Emergency Director and REC training should include the importance of prompt emergency classification and the necessity of timely Protective Action Recommendations during a General Emergency.
(3) Future scenarios should be developed to clarify the radiation monitor readings, i.e., if a radiation monitor indicates erratic, give the range that the monitor is erratic instead of simply stating that the monitor is erratic.
We expect this to be completed by April 1, 1983.
Weakness An apparent (simulated) overexposure occurred about 10:40 A.M. when an equipment operator was sent to the Auxiliary Building to check the two containment fan coil breakers as a response to Message 10A in the scenario.
This equipment operator did not start from the Operations Support Center (OSC) and consequently he had no Health Physics representative to monitor his pathway for radiation levels.
He passed through a high radiation area without being aware.
This indicates inadequate access control of plant personnel during an emergency.
Response
At approximately 10:40 A.M., a plant evacuation was ordered. The Auxiliary Building Equipment Operator remained at his watch station, which had been normal past practice.
(In most of the past emergency plan drills, the auxiliary operators were not involved and were told to stay at their routine work station which is what this individual did during the exercise.) When requested by the Control Room, who contacted him by paging him, the Auxiliary Building Equipment Operator proceeded to check the Containment Fan Coil Breakers.
In doing so, he passed through simulated high radiation areas,'
unknowingly, since he was not accompanied by a drill controller.
When the Control Room Operator learned the Auxiliary Operator had not gone through the OSC for entry he requested the individual to report to the OSC.
PI122782RLA01
Mr. J. A. Hind December 29, 1982 Page 4 Based on radiation levels in the scenario, the route the operator used while checking the breakers, and the time he spent in the area, an apparent (simulated) overexposure did not result.
Exposure was estimated at 165-250 mrem.
To improve the exposure control of the Auxiliary Building Operators, specific evacuation criteria for the Auxiliary Building Operators will be added to F3-9, " Emergency Evacuation".
This also shall be incorporated as part of the operator training cycle.
We expect this to be completed by April 1,1983.
Sincerely, M
C. E. L Uson Director, Nuclear Generation cc: Messrs. G. Charnoff C. Feierabend PI122782RLA01
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