ML20030A411
| ML20030A411 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 01/09/1974 |
| From: | James Shea US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8101090454 | |
| Download: ML20030A411 (3) | |
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UNITED STATES
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7 ATOMIC ENERGY COMMISSION
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DOCKET N0: 50-155 LICENSEE: Consumers Power Company FACILITY: Big Rock Point MINUTES OF MEETING WITH CONSUMERS POWER COMPANY OF MICHIGAN REGARDING THE ADDITION OF AUTO-DEPRESSION CAPABILITY TO THE BIG ROCK POINT PLANT Representatives of Consumers Power Company and the AEC (see attachment) met in Bethesda on December 5, 1973, to discuss seismic design, pipe and vessel code, instrumentation, redundancy, and reliability require-ments for the reactor auto-depressurization system proposed for Big Rock Point. Reference was made to previous Consumer Power Company submittals:
1.
Special Report No.15
" Preliminary Description of Reactor Depressurization System", July 19, 1973, submitted to AEC by CPCo letter dated July 24, 1973.
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" Big Rock Point Loss of Coolant Analysis with Automatic Depres-surization and NFS Demonstration Fuel" submitted to AEC by letiter dated September 22, 1972.
It was emphasized by CPCo that the system is designed so that no single failure will actuate or prevent actuation of the system and that a two-minute delay after receipt of the auto-depressurization actuation signal is necessary to allow personnel evacuation of the containment structure before the reactor vessel is depressurized to containment.
A quench tank containing cold water about equal to the primary coolant water volume is provided to quench steam released unintentionally from one relief valve. During auto-depressurization, quenching would occur for about 40 seconds af ter which the primary system steam would no longer be condensed and would pass through the heated quench tank water to the containment structure. Accidental opening of one relief valve, with failure to isolate, could activate the entire blowdown system (3 or 4 relief valves of approximately 800,000 lbs/hr flow capacity each at 1350 psi) when low level steam drum and reactor vessel signals are received coincidentally since auto-depressurization is activated due to loss of water by level signals from the steam drum and reactor vessel.
The need for further evaluation of manual operation and isolation capability was indicated.
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% January 9,1974 Seismic design criteria fcr the proposed modifications are based on review of earthqurAes that have been recorded for the area and statistical considerations. The new T connection for the relief valve header to be installed in the 12-inch steam line will not be hydrostatically tested but will be 100% radiographed.
The quench tank, although not required during auto-depressurization, is designed not to fail during accident conditions to avoid the damage potential resulting from the release of the tank water. The significant change discussed during the meeting involved the decision to use a small quench tank, as discussed abcve, instead of the spent fuel pool water with the result that containment pressurization is greater than originally planned using spent fuel water-steam suppression but less than DBA LOCA pres-surization that has been previously evaluated.
Component delivery schedules, according to CPCo, may not be consistent with completion of the modification to conform with the Interim Acceptance ECCS Criteria by July 1974.
A final design report is expected during January 1974.
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Enclosure:
List of Attendees cc w/ enclosure:
M. Sewell, CPCo AEC PDR L Reading RP Reading E. G. Case A. Giambusso R. S. Boyd RP/TR Assistant Directors RP/TR Branch Chiefs T. J. Carter J. M. Hendrie J. J. Shea J. Scinto D. Nelson ACRS (16)
K. Kapur i
R. Pollard D. Bernreuter l
i LIST OF ATTENDEES Name Affiliation D. DeMoor
. Consumers Power Company F. Macri Censumers Power Company J. Rang Consumers Power Company R. Sewell Consumers Power Company.
J. Henry McPherson Associates Inc.
D. Wilder Suntac Nuclear F. Muellner Suntac Nuclear J..Shea AEC - Licensing K. Kapur AEC - Licensing R. Pollard AEC - Licensing D. Bernreuter AEC - Licensing i
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