05000321/LER-2009-006, Regarding Main Control Room Air Conditioner Inoperable Due to Inoperable Solenid Valve
| ML100430347 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 02/05/2010 |
| From: | Madison D Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-10-0219 LER 09-006-00 | |
| Download: ML100430347 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 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)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3212009006R00 - NRC Website | |
text
Denn,s R. Madison Southern Nuclear Vice Pres1Cjenl. Hatch Operating Company. Inc.
PI3nl EdWlf1 !. Halch 110)R 'ialcl, Parkwny Nortt1 Baxley. Georqla 31513 rei Q~2 S31.585g
~a. 912.366 20n SOUTHERN A COMPANY February 5. 2010 Docket No.:
50-321; 50-366 NL-10-0219 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Licensee Event Report Main Control Room Air Conditioner Inoperable Due to Inoperable Solenoid Valve Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.73(a)(2)(i)(B), Southern Nuclear Operating Company is submitting the enclosed Licensee Event Report (LER) concerning inoperable main control room air conditioner due to an inoperable solenoid valve.
This letter contains no NRC commitments. If you have any questions, please advise.
Sincerely.
~'T7fvL' D. R. Madison Vice President - Hatch DRMlMJK/
Enclosure: LER 1-2009-006 cc: Southern Nuclear Operating Company Mr. J. T. Gasser. Executive Vice President Ms. P. M. Marino. Vice President Engineering RTYPE: CHA02.004 U. S. Nuclear Regulatorv Commission Mr. L A. Reyes, Regional Administrator Mr. D. N. Wright, NRR Project Manager - Hatch Mr. E. D. Morris, Senior Resident Inspector - Hatch
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO, 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may not conduct or sponsor, and a person is not required to respond 10, the information collection.
- 13. PAGE Edwin I. Hatch Nuclear Plant Unit I 05000321 1 OF 4
- 14. TITLE Main Control Room Air Conditioner Inoperable Due To Inoperable Solenoid Valve
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACiliTY NAME DOCKET NUMBER SEQUENTIAL REV MONTH DAY YEAR YEAR NUMBER NO, MONTH DAY YEAR Edwin I. Hatch Nuclear Plant Unit 2 05000366 FACILITY NAME DOCKET NUMBER 12 15 2009 2009 - 006 -
0 02 05 2010 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply) o 20.2201 (b) o 20.2203(a)(3)(i) o 50.73(a)(2)(i)(C) o 50, 73 (a)(2)(vii)
I o 20.2201 (d) o 20.2203(a)(3)(ii) o 50.73(a)(2)(ii)(A) o 50.73(a)(2)(viii)(A) o 20.2203(a)(1) o 20.2203(a)(4) o 50.73(a)(2)(ii)(B) o 50.73(a)(2)(viii)(B) o 20,2203(a)(2)(i) o 50,36(c)(1 )(i)(A) o 50.73(a)(2)(iii) o 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL o 20,2203(a)(2)(ii) o 50,36(c)(1 )(ii)(A) o 50.73(a)(2)(iv)(A) o 50.73(a)(2)(x) o 20.2203(a)(2)(iii) o 50.36(c)(2) o 50,73(a)(2)(v)(A) o 73.71 (a)(4) o 20.2203(a)(2)(iv) o 50.46(a)(3)(ii) o 50.73(a)(2)(v)(B) o 73.71 (a)(5) 99.6 o 20.2203(a)(2)(v) o 50,73(a)(2)(i)(A) o 50.73(a)(2)(v)(C) o OTHER o 20.2203(a)(2)(vi)
[gI 50,73(a)(2)(i)(8) o 50.73(a)(2)(v)(O)
Specify in Abstract below or in NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER I~ELEPHONE NUMBER (Include Area Code)
~~~~YNAME in I. Hatch I Steve Tipps, Principal Licensing Engineer 912-537-5880 MANU-REPORTABLE MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT
CAUSE
SYSTEM COMPONENT FACTURER TO EPIX FACTURER TO EPIX A
BI SHV V030 YES
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED SUBMISSION MONTH DAY YEAR o YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
[gI NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On December 15, 2009 it was identified that the plant was operating in a condition prohibited by the Technical Specification (TS). The cooling for the main control room (MCR) air conditioning was no longer single failure proof. Further investigation revealed that on January 6, 2006 valve IP41-F123A was identified as not having any stem travel. This valve is in the Plant Service Water (PSW) cooling line for the air conditioner for the office outside the MCR boundary and outside of the area serviced by the MCR air conditioner. This valve is one of two valves that are designed to isolate in the event of a pipe rupture to ensure adequate flow is maintained for MCR air conditioner cooled by Division I PSW.
Since the valve would not isolate, this portion of the line would no longer be considered single failure proof, which should have resulted in entry into the condition required by the TS.
This event was caused most recently by the failure of the operating shift team to recognize the significance of the failure of the isolation valve.
Corrective actions include, update existing procedures to require design modifications be reviewed by Licensing; review the implementing design modification for additional impacts; plan to provide alternate cooling source for the annex cooler, and include Lessons Learned in operability training for licensed personnel.
NRC FORM 366 (9*2007)
PRINTED ON RECYCLED PAPER (If more space is required, use additional copies of NRC Form 366A)
PLANT AND SYSTEM IDENTIFICATION
General Electric Boiling Water Reactor Energy Industry Identification System codes appear in the text as (EllS Code XX).
DESCRIPTION OF EVENT
On December 15,2009 Unit I was operating at 2792 CMWTh 99.6 percent rated thermal power, Unit 2 was operating at 2792 CMWTh, 99.6 percent rated thermal power. On that date it was identified that the plant was operating in a condition prohibited by the Technical Specifications in that the cooling for the main control room air conditioning was no longer single failure proof. Further investigation revealed that on January 6, 2006 valve IP41-F123A was identified as not having any stem travel when the valve is supposed to automatically close. This valve is in the Plant Service Water (pSW, EllS Code BI) cooling line for the air conditioner for the Operations Shift Manager's office which is outside the main control room boundary and outside of the area serviced by the main control room air conditioners (EllS Code VI). This additional air conditioner was added in 1982 as part of a design modification which added office space adjacent to the main control room in order to allow the space in the main control room to be better utilized. The IP41-F123A valve is one of two valves that are designed to automatically isolate in the event of a failure of the non-safety related portion of the PSW line during a design basis seismic event, because that portion of the PSW line is not seismic class IE by design. The isolation of this section of piping ensures that adequate flow is maintained for main control room air conditioner(s) cooled by Division I PSW. Since valve I P41-F123A would not isolate, this portion of the line would no longer be considered single failure proof, which should have resulted in entry into the condition required by the Technical Specifications for the loss of Main Control Room Air Conditioner Units which are aligned to Division I PSW. The cooling for the Main Control Room Air Conditioner Units is described in the Technical Specifications Bases, but not to the component detail that would make it obvious that the cooling system was no longer single failure proof. Since the PSW valve that failed provides cooling to a non-safety related air conditioner unit, the operating shift team did not recognize the significance of the failure of this isolation valve.
Additional information was also available in CR 2009111670 that included a review of the work history for valve IP41-F123A which contained a history of unreliable operation. This should have prompted a review of the operability of the component based on questions regarding its continued reliability. Upon identification of the function played by this component and its degraded condition, the affected PSW cooling line was isolated. It will remain in that state until corrective actions are taken to address the degraded condition and reliability of the isolation valve.
CAUSE OF EVENT
This event was caused most recently by the failure of the operating shift team to recognize the significance of the failure of isolation valve IP41-F123A in that the cooling system for the main control room air conditioner units cooled by Division I PSW were no longer single failure proof. As a result the required Technical Specification Required Action Statement for inoperable main control room air conditioner unit was not entered on December 10, 2009, nor was it entered on January 6, 2006, when the condition was first identified. There was a missed opportunity to strengthen the Technical Specifications and Bases as well as to establish the periodic testing of the isolation valves when preparing the design change package that installed the additional air conditioner. PRINTED ON RECYCLED PAPER
4 NRC FORM 355A LICENSEE EVENT REPORT (LER) u.s. NUCLEAR REGULATORY COMMISSION (9-2007)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 5. LER NUMBER
- 3. PAGE SEQUENTIAL IREVISION 05000321 YEAR NUMBER NUMBER Edwin I. Hatch Nuclear Plant Unit I t-------'I 3
OF 05000366 2009 006 0
REPORTABILITY ANALYSIS AND SAFETY ASSESSMENT This event is reportable under to CFR 20.73(a)(2)(i)(B), Any operation or condition which was prohibited by the plant's Technical Specifications. Since valve IP41-F123A would not isolate, this portion of the line would no longer be single failure proof, which should have resulted in entry into the Condition required by the Technical Specifications for the loss of Main Control Room Air Conditioner Units which are aligned to the Division I of PSW, but did not.
The Control Room AC portion of the Main Control Room Environmental Control System (hereafter referred to as the Control Room AC System) provides temperature control for the control room following isolation of the control room. The Control Room AC System consists of three 50 percent capacity subsystems that provide cooling and heating of control room supply air. Each subsystem consists of an air handling unit (AHU) (i.e., cooling coils and fan), water cooled condensing units, refrigerant compressors, ductwork, dampers, and instrumentation and controls to provide for control room temperature control. The condensing units receive cooling water from the Plant Service Water System. One condensing unit receives cooling from Division I PSW, one unit is capable of receiving cooling from both Divisions I and II PSW, the other condensing unit receives cooling from Division II PSW. The Control Room AC System is designed to provide a controlled environment under both normal and accident conditions. Two subsystems provide the required temperature control to maintain a suitable control room environment for a sustained occupancy of 14 persons. The design conditions for the control room environment are 72-79 Fahrenheit and less than 75 percent relative humidity.
In the event the loss of the non-seismic piping was to occur, there are valves available in the seismic portion of the Control Room AC system to provide isolation from the Division 1 PSW thus ensuring the cooling system remains operable. It should be noted that the main control room air conditioning system is manually placed into service. As long as the alignment and operation of the system can be manually accomplished operability of the system is maintained. Should the condition of the system become degraded due to some portion of the system no longer being "single failure" proof, a Tech Spec RAS must be entered. Since loss of cooling water does not result in the design limits being exceeded immediately and the area is continuously inhabited, it is reasonable to expect the operating crews to identify and compensate for the loss of cooling in a reasonable period of time.
Based on this analysis, it is concluded that this event had no adverse impact on nuclear safety. PRINTED ON RECYCLED PAPER LICENSEE EVENT REPORT (LER) u.s. NUCLEAR REGULATORY COMMISSION (9-2007)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE SEQUENTIAL IREVISION 05000321 YEAR NUMBER NUMBER Edwin I. Hatch Nuclear Plant Unit I I
4 OF 4
05000366 2009 006 o
CORRECTIVE ACTIONS
The current plans are to provide cooling to MCR Annex NC unit using non-safety related cooling water.
The development of training for licensed personnel for modifications implemented will be reviewed to ensure that the Lessons Learned from this event are considered when preparing and delivering this training. The Lessons Learned from this event will be included in licensed re-qualification segments for licensed personnel and in future operability determination training.
Revise NMP-AD-O 10 to require that Design Change Packages be reviewed by Nuclear Licensing in order to determine if adequate information is contained in the Technical Specifications and/or Bases that ensure the operating shift teams have adequate guidance to recognize the significance of the modification and how it can impact the operability of the system with which it interfaces.
ADDITIONAL INFORMATION
Other Systems Affected: None
Failed Components Information
Master Parts List Number: IP41-F123A EllS System Code: BI Manufacturer: Valcor Reportable to EPIX: Yes Model Number: V526-563 1-17 Root Cause Code: A Type: Valve, Valve, Shutoff EllS Component Code: SHV Manufacturer Code: V030 Commitment Information: This report does not create any new permanent licensing commitments.
Previous Similar Events
This is considered to be an isolated event of this nature. PRINTED ON RECYCLED PAPER