05000336/LER-2012-002, Completion of Plant Shutdown Required by Technical Specifications
| ML12285A229 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 10/02/2012 |
| From: | Scace S Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 12-613 LER 12-002-00 | |
| Download: ML12285A229 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| LER closed by | |
| IR 05000245/2012005 (16 January 2013) | |
| 3362012002R00 - NRC Website | |
text
79~Dominion Dominion Nuclear Connecticut, Inc.
Millstone Power Station Rope Ferry Road Waterford, CT 06385 OCT 0 0
U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Serial No.
MPS Lic/TGC Docket No.
License No.12-613 RO 50-336 DPR-65 DOMINION NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNIT 2 LICENSEE EVENT REPORT 2012-002-00 COMPLETION OF PLANT SHUTDOWN REQUIRED BY TECHNICAL SPECIFICATIONS This letter forwards Licensee Event Report (LER) 2012-002-00 documenting the completion of a plant shutdown required by technical specifications at Millstone Power Station Unit 2 on August 12, 2012.
This LER is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(A) "the completion of any nuclear plant shutdown required by the plant's technical specifications".
If you have any questions or require additional information, please contact Mr. William D. Bartron at (860) 444-4301.
Sincerely,
'St epp i flE./ ScJaclea~
Site Vice President - Millstone Attachments: 1 Commitments made in this letter: None
Serial No.12-613 Docket No. 50-336 Licensee Event Report 2012-002-00 Page 2 of 2 cc:
U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 J. S. Kim Project Manager - Millstone Power Station U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 08 C2A Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station
Serial No.12-613 Docket No. 50-336 Licensee Event Report 2012-002-00 ATTACHMENT LICENSEE EVENT REPORT 2012-002-00 MILLSTONE POWER STATION UNIT 2 DOMINION NUCLEAR CONNECTICUT, INC.
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10/2010)
, the NRC may not conduct or sponsor, digits/characters for each block) and a person is not required to respond to, the information collection.
- 3. PAGE Millstone Power Station - Unit 2 05000336 1 OF2
- 4. TITLE Completion of Plant Shutdown Required By Technical Specifications
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR 05000 NUMBER NO.
FACILITY NAME DOCKET NUMBER 08 12 2012 2012-002-00 10 02 2012 05000
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR Check all that apply)
- 9. OPERATING MODE 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201 (d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1 )(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x)
- 10. POWER LEVEL 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71 (a)(5) 065 20.2203(a)(2)(v)
X 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specify in Abstract below or in
- 1.
Event Description
At 13:46 on August 12, 2012, Millstone Power Station Unit 2 (MPS2) completed a controlled plant shutdown from Mode 1 to Mode 3 (Hot Standby) as required by plant Technical Specification (TS) 3.7.11 Ultimate Heat Sink. TS 3.7.11 stipulates the ultimate heat sink (UHS) shall be operable with a water temperature of less than or equal to 75 degrees F. TS 3.7.11 Action a. allows continued plant operation when UHS temperature is between 75 degrees F and 77 degrees F, provided UHS temperature averaged over the previous 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is verified to be less than 75 degrees F once per hour. Otherwise, be in Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
The UHS [BS] for MPS2 is Long Island Sound. The UHS temperature had initially gone above the temperature limit at 16:30 on August 11, 2012, but had cooled below the limit based on environmental factors. At 00:44 on August 12, 2012 the UHS temperature again rose above the TS limit and operators initiated a plant shutdown as required by plant TS 3.7.11. At 02:55 the Shift Manager directed that power be stabilized at 65% power since UHS temperatures had cooled below the TS limit. Plant power was held at approximately 65% power until 08:35 on August 12, 2012 when temperature again rose above the UHS limit. The Shift Manager directed completion of the plant shutdown from Mode 1 to Mode 3, completed at 13:46 on August 12, 2012. The UHS temperature continued to cycle above and below the TS limit. The plant entered Mode 5 Cold Shutdown at 22:31 on August 13, 2012.
The last time the UHS 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> average temperature went above 75 degrees F was August 14, 2012 at 14:35.
This condition is being reported pursuant to 10 CFR 50.73(a)(2)(i)(A) "the completion of any nuclear plant shutdown required by the plant's technical specifications".
- 2.
Cause
Prolonged hot weather in the Long Island Sound, in conjunction with high humidity during the day and minimal cooling at night resulted in sustained elevated cooling water temperature (UHS) supplied to the plant. Ambient air temperatures in July were the hottest on record in the contiguous United States since record keeping began in 1895 according to the National Oceanic and Atmospheric Administration, and temperatures continued to remain high in August.
- 3.
Assessment of Safety Consequences
The limitations on the ultimate heat sink temperature ensure that sufficient cooling capacity is available to either,
- 1) provide normal cooldown of the facility, or 2) to mitigate the effects of accident conditions within acceptable limits.
The limitations on maximum temperature are based on a 30-day cooling water supply to safety related equipment without exceeding their design basis temperature. The UHS temperature fluctuations were relatively short in duration.
The UHS temperature never exceeded the upper limit of 77 degrees F.
- 4.
Corrective Action
Since the shutdown was required by environmental factors beyond licensee control, no corrective actions were required.
5,
Previous Occurrences
There are no previous occurrences identified.
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].
1