05000293/LER-2016-005, Regarding Ultimate Heat Sink and Salt Service Water System Declared Inoperable
| ML16298A389 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 10/13/2016 |
| From: | Perkins E Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 16-005-00 | |
| Download: ML16298A389 (8) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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) 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)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 2932016005R00 - NRC Website | |
text
~Entergx October 13, 2016 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth. MA 02360
SUBJECT:
Licensee Eyent Report 2016-005-00, Ultimate Heat Sink and Salt Service Water System Declared Inoperable Pilgrim Nuclear Power Station Docket No. 50-293 Renewed License No. DPR-35 LETTER NUMBER: 2.16.062
Dear Sir or Madam:
The enclosed Licensee Event Report 2016-005-00, Ultimate Heat Sink and Salt Service Water System Declared Inoperable, is submitted in accordance with 1 O Code of Federal Regulations 50.73.
If you have any questions or require additional information, contact me at (508) 83p-8323.
There are no regulatory commitments contained in this letter.
Sincerely, Eve~~.~~t_~ ~
Manager, Regulatory Assurance EPP/sc Attachment: Licensee Event Report 2016-005-00, Ultimate Heat Sink and Salt Service Water System Declared Inoperable (5 Pages)
Entergy Nuclear Operations, Inc.
- Pilgrim Nuclear Power Station cc:
Mr. Daniel H. Dorman Regional Administrator, Region I U.S. Nuclear Regulatory Commission 2100 Renaissance Blvd., Suite 100 King of Prussia, PA 19406-2713 Ms. Booma Venkataraman, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-8C2A Washington, DC 20555 NRC Senior Resident Inspector Pilgrim Nuclear Power Station Letter No. 2.16.062 Page 2 of 2
Attachment Letter Number 2.16.062 Licensee Event Report 2016-005-00 Ultimate Heat Sink and Salt Service Water System Declared Inoperable (5 Pages)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 (11-2015)
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Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.
R Reported lessons learned are incorporated into the licensing process and fed back to industry.
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Send comments regarding burden estimate to the FOIA, Privacy and Information Collections
~~
y.7,;fJ LICENSEE EVENT REPORT (LER)
Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
, 3. PAGE 1
Pilorim Nuclear Power Station 05000293 OF5
- 4. TITLE Ultimate Heat Sink and Salt Service Water System Declared Inoperable
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED I
SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR N/A N/A 2016 FACILITY NAME DOCKET NUMBER 08 15 2016 2016-005 - 00 10 13 N/A N/A
- 9. OPERA TING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that ann/y)
D 20.2201 (b)
D 20.2203(a)(3)(i)
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A)
D 20.2201 (d)
D 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B)
N D 20.2203(a)(1)
D 20.2203(a)(4)
D 50.73(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(i)
D 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2){x)
- 10. POWER LEVEL D 20.2203(a)(2)(ii)
D 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 13.11(a)(4)
D 20.2203(a)(2)(iii)
D 5o.3s(c)(2)
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50.73(a)(2)(v)(B).
D 13.11 (a)(5)
D 20.2203(a)(2)(iv)
D 50.46(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 13.77(a)(1) 70 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
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- 50. 73(a)(2)(v)(D)
D 13.77(a)(2)(i)
D 20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 13.11 (a)(2)(ii)
D 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in SEQUENTIAL NUMBER 005 REV NO.
00 Operation Action Statement (LCO-AS) for Salt Service Water (SSW) inlet temperature exceeding the TS limit in TS 3.5.B.4. The LCO-AS was subsequently exited at 1651 hours0.0191 days <br />0.459 hours <br />0.00273 weeks <br />6.282055e-4 months <br /> when the temperature of SSW trended to below the TS limit.
Under certain design conditions, the SSW system is required to provide cooling water to various heat exchangers such as the Reactor Building Closed Cooling Water (RBCCW) and Turbine Building Closed Cooling Water (TBCCW) systems. When the inlet temperature to these supplied loads exceeds the 75 degree F limit established in the TS, the SSW system is conservatively declared inoperable until the temperature trends below this value. On August 16, 2016 this condition existed for 59 minutes with the maximum temperature documented at 75.1 degrees F.
CAUSE OF THE EVENT
The cause of the sea water inlet temperature exceeding the 75 degree F TS criterion was sustained increased sea water surface temperature in Cape Cod Bay due to summer weatper conditions and recirculation of water from the plant's discharge due to wind and tidal conditions.
The lack of margin available between the possible maximum sea water temperature and the design analytical limit influenced the plant's response. The possibility that both loops of containment cooling might be declared inoperable because of high UHS temperature was recognized when the 75 degree F Technical Specification limit was established in 1997. However, at that time based on historical temperature data and knowledge of the behavioral characteristics of the bay and local meteorology, it was considered highly improbable that the plant would ever be shut down because of high UHS temperature with the limit set at 75 degrees F. On these bases, the UHS temperature limit of 75 degrees F was considered acceptable.
CORRECTIVE ACTIONS
To increase the margin between the Salt Service Water (SSW) design basis inlet temperature and expected environmental operating conditions an engineering eval,uation that supports increasing the margin between the Salt Service Water (SSW) design basis inlet temperature and expected environmental operating conditions is being performed. Appropriate regulatory actions will be taken based on the results of that evaluation.
As an interim action, procedural enhancements to deal with elevated salt service water temperature will be implemented.
Additional corrective actions will be implemented as necessary within the corrective action program.
SAFETY CONSEQUENCES
SEQUENTIAL NUMBER 005 REV NO.
00 There were no consequences to the general safety of the public, nuclear safety, industrial safety, and radiological safety due to this event.
The safety function of the SSW System is to transfer heat from all systems and components cooled by the Reactor Building Closed Cooling Water (RBCCW) System to Cape Cod Bay. The SSW System provides a continuous supply of cooling water to the secondary side of the RBCCW heat exchangers under normal, shutdown, transient, and accident conditions. Design and accident analyses for the station have been performed with the assumption that the SSW inlet temperature would average 75 degrees F maximum.
Increased SSW inlet temperatures reduce the ability of the SSW System to remove heat from the RBCCW System.
Following an event in 2013 where SSW inlet temperature exceeded 75 degrees F, an engineering evaluation was performed to address the consequences of the temperature excursion and to determine whether the safety function would still have been fulfilled. This evaluation assumed an event where the SSW inlet temperature exceeded 75 degrees F and remained less than 78 degrees F for short durations, with the 12-hour rolling average less than 75 degrees F. This evaluation concluded that all systems, structures, and components would be capable of performing their safety functions under the assumed conditions. The temperature excursion that occurred on August 15, 2016 is bounded by that evaluation. Accordingly, the safety function of the Salt Service Water System would have been satisfied based on the maximum temperature recorded and the short duration of the excursion.
There was no adverse impact on the public health or safety.
REPORT ABILITY This event is reportable under 1 O CFR 50. 73(a)(2)(v)(B) and 10 CFR50. 73(a)(2)(v)(D), Event or Condition that Could Have Prevented Fulfillment of a Safety Function.
PREVIOUS EVENTS LERs for the previous ten years were reviewed for UHS and SSW Pumps being inoperable. These LERs are summarized as follows:
LER 2015-006 - Ultimate Heat Sink and Salt Service Water System Declared Inoperable LER 2013-007 - Ultimate Heat Sink and Salt Service Water System Declared Inoperable ENERGY INDUSTRY IDENTIFICATION SYSTEM (EllS) CODES The EllS codes for Components and Systems referenced in this report are as follows:
SYSTEMS CODES Ultimate Heat Sink (UHS) System (Cape Cod Bay)
BS
REFERENCES:
- 1) Pilgrim Nuclear Power Station LER 2013-007, Ultimate Heat Sink and Salt Service Water System Declared Inoperable, dated 9/13/2013 (NRC Accession No. ML13266A242).
- 2) Pilgrim Nuclear Power Station LER 2015-006, Ultimate Heat Sink and Salt Service Water System Declared Inoperable, dated 10/7/2015 (NRC Accession No. ML15289A231),