05000410/LER-2014-006, Regarding Secondary Containment Inoperability Following Auxiliary Boiler Trip

Regarding Secondary Containment Inoperability Following Auxiliary Boiler Trip

ML14161A147
Person / Time
Site:	Nine Mile Point
Issue date:	05/23/2014
From:	John Stanley Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 14-006-00
Download: ML14161A147 (8)

LER-2014-006, Regarding Secondary Containment Inoperability Following Auxiliary Boiler Trip

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
4102014006R00 - NRC Website

text

V Exelon Generation, Jim Stanley Plant Manager - Nine Mile Point P.O. Box 63 Lycoming, NY 13093 315 349 5205 Office www.exeloncorp.com james.stanley@exeloncorp.com May 23, 2014 U.S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 Docket No. 50-410

Subject:

Licensee Event Report 2014-006, Secondary Following Auxiliary Boiler Trip Containment Inoperability In accordance with 10 CFR 50.73(a)(2)(v)(C), please find attached Licensee Event Report 2014-006, Secondary Containment Inoperability Following Auxiliary Boiler Trip.

There are no regulatory commitments in this submittal.

Should you have questions regarding the information in this submittal, please contact Everett (Chip) Perkins, Director Licensing, at (315) 349-5219.

Sincerely, 0-L k 9 A' '

JJS/KP

Attachment:

Licensee Event Report 2014-006, Secondary Containment Inoperability Following Auxiliary Boiler Trip cc:

Regional Administrator, Region I, USNRC Project Manager, USNRC Resident Inspector, USNRC

&L 01'902

ATTACHMENT LICENSEE EVENT REPORT 2014-006 SECONDARY CONTAINMENT INOPERABILITY FOLLOWING AUXILIARY BOILER TRIP Nine Mile Point Nuclear Station, LLC May 23, 2014

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0113112017 (02-2014)

(02'204 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 />.

Reported lessons learned are incorporated into the licensing process and fed back to industry.

(*)

Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by LICENSEE EVENT REPORT (LER) intemet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and (See Page 2 for required number of 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 digits/characters for each block) control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

3. PAGE Nine Mile Point Unit 2 05000410 1 OF 6

4. TITLE Secondary Containment Inoperability Following Auxiliary Boiler Trip

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED M

FACILITY NAME DOCKET NUMBER YEAR NUMBER NO.

MONTH DAY YEAR N/A N/A FACILITY NAME DOCKET NUMBER 3

4 2014 2014 006

- 00 5

23 2014 N/A N/A

9. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)

El 20.2201(b)

[E 20.2203(a)(3)(i)

El 50.73(a)(2)(i)(C)

[I 50.73(a)(2)(vii)

[-

20.2201(d)

El 20.2203(a)(3)(ii)

El 50.73(a)(2)(ii)(A)

El 50.73(a)(2)(viii)(A)

El 20.2203(a)(1)

[E 20.2203(a)(4)

[E 50.73(a)(2)(ii)(B)

El 50.73(a)(2)(viii)(B)

[] 20.2203(a)(2)(i)

El 50.36(c)(1)(i)(A)

El 50.73(a)(2)(iii)

El 50.73(a)(2)(ix)(A)

10. POWER LEVEL El 20.2203(a)(2)(ii)

El 50.36(c)(1)(ii)(A)

El 50.73(a)(2)(iv)(A)

[-

50.73(a)(2)(x)

El 20.2203(a)(2)(iii)

El 50.36(c)(2)

El 50.73(a)(2)(v)(A)

El 73.71(a)(4)

El 20.2203(a)(2)(iv)

[I 50.46(a)(3)(ii)

El 50.73(a)(2)(v)(B)

El 73.71(a)(5) 1E 20.2203(a)(2)(v)

El 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C)

El OTHER El 20.2203(a)(2)(vi)

El 50.73(a)(2)(i)(B)

El 50.73(a)(2)(v)(D)

Specify in Abstract below or in El 2.223(a(2)(i) 0.7(a)()(i(B)

C.

INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THAT CONTRIBUTED TO THE EVENT:

There were no inoperable structures, components or systems that contributed to the event other than the components identified in Section I.B.

D. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES

The dates, times and major occurrences for this event are as follows:

March 23 1943 Operators log the start of Auxiliary Boiler 'B' 2ABM-B1 B to support plant shutdown 2059 Operators line up auxiliary steam from the operating Auxiliary boiler 'B' 2ABM-B1 B to the auxiliary heat exchangers to support plant shutdown 2303 Auxiliary Boiler'A' 2ABM-BIA started 2306 Auxiliary Boiler'B' 2ABM-B1 B trips 2329 Auxiliary Boiler 'A' 2ABM-BIA trips on high ground current March 24 0031 Secondary Containment exceeds TS limit 0034 Secondary Containment differential pressure (dP) is restored, Secondary Containment is declared operable 0102 Operators start Auxiliary Boiler 'B' 2ABM-B1 B in manual 0526 Vent WRGMS restored

E. OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED

No other systems or secondary functions were affected beyond the systems discussed in Section I.B.

F. METHOD OF DISCOVERY

This condition was recognized by Operations as they monitored secondary containment dP becoming positive and exceeding the TS limit.

G. MAJOR OPERATOR ACTION:

Operators managed the event through use of N2-EOP-SC, "Secondary Containment -

Flowchart" and EPMP-EPP-13, "Equipment Important to Assuring Implementation Capability of the Emergency Preparedness Program". With the use of these procedures, an alternate means to sample gaseous release from the stack and maintain the secondary containment envelope in a vacuum condition was established. The dP subsequently returned to greater than 0.25 inch vacuum water gauge following a duration of 3 minutes outside of TS limits.

H. SAFETY SYSTEM RESPONSES:

This event was caused when the Reactor Building was isolated and building dP began to exceed the TS limit. The GTS performed as expected to restore the required building dP.

II. CAUSE OF EVENT

The cause of this event is attributed to the failure of the auxiliary boilers. The loss of this equipment resulted in challenges to Reactor Building heating and operation of the building ventilation. The maintenance of primary containment heating is significant for maintaining the limits of the secondary containment draw down analysis and protecting design attributes such as containment penetration nil ductility temperature. Isolation of the Reactor Building resulted in the loss of Vent WRGMS.

Ill. ANALYSIS OF THE EVENT:

The event described in this LER is reportable under 10 CFR 50.72 (b)(3)(v)(C) and 10 CFR 50.73(a)(2)(v)(C) as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material. In addition, isolation of the Reactor Building vent radiation monitor which occurred during the event is reportable under 10 CFR 50.72 (b)(3)(xiii) and represented a loss of emergency assessment capability.

Decreasing external temperatures combined with the loss of 2ABM-B1 B and 2ABM-B1A challenged operators to maintain Reactor Building heating and the operation of building ventilation. Actions taken by Operators resulted in the isolation of the Reactor Building and the non functionality of the Ventilation Wide Range Gaseous Monitoring System. The change in secondary containment dP which eventually exceeded TS limits was detected by operators as they implemented measures to preserve design parameters. The causal analysis noted that inadequate equipment maintenance management and chemistry control adversely impacted the reliability of the auxiliary boilers. The less than adequate maintenance performance preceding the event resulted in the auxiliary boiler equipment failure.

During this event, the required TS action statements and plant procedures were entered and subsequently exited once the secondary containment dP was restored to above the required TS minimum value. In all cases, the TS required completion time was not exceeded. The secondary containment structural integrity, the ability to automatically isolate the non-safety related Reactor Building Ventilation System, and the GTS availability were not impacted.

Based on the above discussion, it is concluded that the safety significance of this event is low and the event did not pose a threat to the health and safety of the public or plant personnel.

This event does not affect the NRC Regulatory Oversight Process Indicators.

IV. CORRECTIVE ACTIONS

A. ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMAL STATUS:

Operators entered plant procedure N2-EOP-SC as a means to return NMP2 to pre-event normal status.

B. ACTION TAKEN OR PLANNED TO PREVENT RECURRENCE:

Revise a plant procedure for Operations to provide adequate details for system operational requirements and guidelines to ensure operating parameters are maintained within specifications during operation of the boilers.

Revise a plant procedure for Operations to require a chemistry sample be taken each shift, analyzed and reported to Operations when an auxiliary boiler is in operation.

V. ADDITIONAL INFORMATION

A. FAILED COMPONENTS:

The loss of the auxiliary boilers contributed to this event.

B. PREVIOUS LERs ON SIMILAR EVENTS:

A previous LER on a similar event was not identified.

C. THE ENERGY INDUSTRY IDENTIFICATION SYSTEM (EIIS) COMPONENT FUNCTION IDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM REFERRED TO IN THIS LER:

IEEE 803 FUNCTION IDENTIFIER IEEE 805 SYSTEM IDENTIFICATION COMPONENT Reactor Building (BWR)

Reactor Building Ventilation System Reactor Building Vent Radiation Monitoring System Auxiliary Boiler D. SPECIAL COMMENTS:

None N/A PDIC MON BLR NG VA IL SA