ML13031A630
| ML13031A630 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 08/09/2012 |
| From: | James Krafty NRC/RGN-I/DRP/PB5 |
| To: | Josephine Ambrosini, Ronald Bellamy, Joseph Deboer, Brian Haagensen, James Kim, Thomas Setzer, Keighley E Division of Operating Reactor Licensing, NRC/RGN-I/DRP/PB5 |
| References | |
| FOIA/PA-2013-0045 | |
| Download: ML13031A630 (1) | |
Text
Bellamy, Ronald From:
Krafty, James Sent:
Thursday, August 09, 2012 9:19 AM To:
Ambrosini, Josephine; Haagensen, Brian; Bellamy, Ronald; Setzer, Thomas; Keighley, Elizabeth; DeBoer, Joseph; Kim, James
Subject:
Milstone 2 Service Water Temperature Millstone 2 has been in and out of TS 3.7.11 over the past few days. The current concern is that the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> average temperature will exceed 75F. If this happens, they will be required to go to cold shutdown.
Unit 2 monitors service water temperature at the inlet to the 3 vital switchgear coolers. They record the highest of the 3 temperatures hourly and use it in calculating the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> average. Because of instrument error, they use 74.5F as the limit to ensure that they do not exceed 75F. Their current 24 hr average temperature is 73.7F. It increased from 73.4F over the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Their TS amendment request is asking to use the average of the 3 temperatures instead of the highest reading in calculating the 24 hr average. Using the average of the 3 temperatures, the 24 hr average would be 73.3F, 0.4F lower.
Unit 2's service water takes a suction 15ft below the LI sound surface. Unit 3 takes their UHS temperature form the average temperature at the inlet to the condenser waterboxes. The circ water pumps take a suction 30ft below the LI sound surface which is less susceptible to surface heating.
Jim 1
7Y