ML13031A634

Email from J. Ambrosini, Ri to J. Ambrosini, Ri Et Al., Millstone Unit 2 UHS: August 12 Updates

ML13031A634
Person / Time
Site:	Millstone
Issue date:	08/12/2012
From:	Josephine Ambrosini NRC/RGN-I/DRP/PB5
To:	Josephine Ambrosini, Bellamy R, Joseph Deboer, Brian Haagensen, James Kim, James Krafty, Thomas Setzer, Keighley E Division of Operating Reactor Licensing, NRC/RGN-I/DRP/PB5
References
FOIA/PA-2013-0045
Download: ML13031A634 (2)

Text

Kim, James From: Ambrosini, Josephine Sent: Sunday, August 12, 2012 2:55 PM To: Ambrosini, Josephine; Bellamy, Ronald; Setzer, Thomas; Keighley, Elizabeth; DeBoer, Joseph; Krafty, James; Haagensen, Brian; Kim, James

Subject:

RE: Millstone Unit 2 UHS: August 12 update (1500)

Updates in bold Bottom Line Up Front: Despite the emergency TS amendment and other engineering attempts to gain margin, Millstone U2 exceeded their ultimate heat sink limit and commenced a TS required shutdown on Sunday, August 12.

Background:

• Engineering. analysis and the averaging of temperatures permitted by the new emergency TS amendment allows Millstone U2 to go to 74.9 0 F and still ensure they meet the 75°F design basis limit for UHS temperature. At 2130 on August 11, Millstone exceeded 74.9°F and entered the TSAS which requires the unit to be in Hot Standby within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

• Millstone commenced a shutdown in accordance with station procedures at 0044 on August 12.

• Weather conditions changed and Millstone entered and exited the UHS temperature limit TS during the course of the next few hours.

• At 0255 on August 12, Millstone exited the UHS TS and stopped their shutdown, holding at approximately 65% power to further evaluate the situation.

Licensee Actions:

• U2 re-entered TSAS at 0830 when the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> average temp got to 74.94°F

• U2 will begin a shutdown to be in Hot Standby by 1430. They will not stop the shutdown this time to avoid cycling the organization, even if conditions improve. Once the Hot Standby walkdowns are complete, Millstone will assess the weather conditions and decide whether or not to continue to Cold Shutdown (assuming they have exited the entry criteria for the TSAS). They have 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> to complete this action.

. Mode 3 reached at 1346

• Containment walkdown briefing at 1900; walkdown to follow

• Reactor cooldown commencing after walkdowns (approximately 2200)

• Expected cold shutdown by tomorrow AM Resident Actions/Assessment:

" Residents reported to the control room at 0300 on August 12 to assess plant conditions and review upcoming plans. At this time there was no decision on time of shutdown, length of shutdown, or scope of any outage work to be performed should the plant remain shutdown.

• Residents to attend briefing and walkdown with licensee this evening Future Actions:

• Residents to accompany licensee on Hot Shutdown walkdowns.

• No decision has been made on length or scope of any outage at this time (0900 on 8/12)

• Outage duration is still indeterminate - more weather analysis to follow (word on the street is at least a week, maybe longer)

Licensee is also looking at U3. U3 has more margin than U2 does in UHS due to design differences, but if the Sound keeps heating up, they could face a similar situation.

Please let me know if you have any additional questions. Thanks.

Jo Ambrosini USNRC Region I Senior Resident Inspector, Millstone 860-447-33.70 2