05000445/LER-2011-003, Regarding Unsuitable Material on Containment Airlock
| ML11363A177 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/19/2011 |
| From: | Flores R Luminant Power, Luminant Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CP-201101540, TXX-11134 LER 11-003-00 | |
| Download: ML11363A177 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4452011003R00 - NRC Website | |
text
Rafael Flores Luminant Power Senior Vice President P 0 Box 1002 011%
& Chief Nuclear Officer 6322 North FM 56 rafael.flores@Luminant.com Glen Rose, TX 76043 Luminant T
C 817 559 0403 F 254 897 6652 CP-201101540 Ref. # 10CFR50.73 TXX-11134 December 19, 2011 U. S. Nuclear Regulatory Commission ATYN: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT DOCKET NOS. 50-445 and 50-446 LICENSEE EVENT REPORT 445/11-003-00, UNSUITABLE MATERIAL ON CONTAINMENT AIRLOCK
Dear Sir or Madam:
Enclosed is Licensee Event Report (LER) 445/11-003-00, "Unsuitable Material on Containment Airlock," for Comanche Peak Nuclear Power Plant (CPNPP) Units 1 and 2.
This letter contains no new regulatory commitments regarding CPNPP Units 1 and 2.
Should you have any questions concerning this submittal, please contact Mr. Tim Hope, Manager, Nuclear Licensing, at (254) 897-6370.
Sincerely, Luminant Generation Company LLC Rafael Flores By:
AFred W. Madden Director, Oversight & Regulatory Affairs Enclosure
- - LER 1-11-003-00 Unsuitable Material on Containment Airlock c -
E. E. Collins, Region IV B. K. Singal, NRR Resident Inspectors, Comanche Peak
Enclosure to TXX-I 1134 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES:10/31/2013 (10-2010)
, the NRC may digitsicharacters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Comanche Peak Nuclear Power Plant (CPNPP) Unit 1 05000 445 1 OF6
- 4. TITLE Unsuitable Material on Containment Airlock
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SUETA RE I
7I FACILITY NAME DOCUMENT NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR A
NUMBER NO.
N/A 10 18 11 2011 I 003 00 12 19 11 FACILrITY NAME DOCUMENT NUMBER I
CPNPP Unit 2 05000 446
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
[] 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[J 50.73(a)(2)(vii) 5 20.2201(d)
El 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
[3 20.2203(a)(1)
[] 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B)
M_
20.2203(a)(2)(i)
E]
50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL [J
20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
[]
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)
E] 73.71(a)(4) 0 El 20.2203(a)(2)(iv)
EJ 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5)
[D 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
[
50.73(a)(2)(v)(C)
El OTHER E] 20.2203(a)(2)(vi)
[]
50.73(a)(2)(i)(B)
[
50.73(a)(2)(v)(D)
VOLUNTARY LER
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (Include Area Code)
Timothy A. Hope, Nuclear Licensingi Managier 254-897-6370CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR YES (If yes, complete 15. EXPECTED SUBMISSION DATE) l0 NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On October 18, 2011 Unit 1 was in Mode 5 for the 1 RF1 5 refueling outage and Unit 2 was in Mode 1 at 100% power. At 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br />, an installed valve on the containment side of the Unit 1 personnel airlock hydraulic system was determined to have an aluminum body. Aluminum is a restricted/limited material in containment because it is not compatible with accident conditions. The aluminum valve body could potentially lose pressure integrity during a LOCA with containment spray actuation.
Subsequently, on October 19 at 2002, two pressure gauges on the Unit 1 personnel airlocks and two pressure gauges on Unit 2 personnel airlocks, located inside the Reactor Containment Buildings, were also found to have an external epoxy coated aluminum casing and pressure boundary parts which have not been completely verified to be resistant to containment spray. The pressure gauges in all 4 airlocks have been isolated by closed ASME Class 2 isolation valves. The cause of this event was an inadequate design change for the airlocks. Corrective actions include encasing the personnel airlock hydraulic system valve inside containment to prevent exposure of the valve body to the sodium hydroxide in the containment spray and removing and replacing the airlock pressure gauges inside containment with stainless steel plugs. All times in this report are approximate and Central Time unless noted otherwise.
NRC FORM 366 (10-2010)
PRINTED ON RECYCLED PAPER (If more space is required, use additional copies of SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES:
On September 14, 2011, at approximately 1600, during performance of a self-assessment for 50.59 reviews, the assessor (Utility, Non-licensed) reviewed an open technical evaluation replacement item (TERI) on the personnel airlock. Since the evaluation was open, the assessor provided feedback to Procurement Engineering regarding a potential issue with the material of an installed valve on the containment side of the hydraulic system for the personnel airlock (1 BS-0053). The Master Equipment List was checked and it indicated that the installed valve was of an appropriate material. Therefore, a Condition Report was not initiated at that point.
On October 3, 2011, at approximately 1421 subsequent to examination with an alloy analyzer of the actual installed valve, it was determined that the Unit 1 hydraulic valve for the containment side of the personnel airlock [EIIS: (NH)(AL)(V)] has an aluminum body which is not appropriate for use in containment. The containment personnel airlock hydraulic system on Unit 2 is different than Unit 1, and since this valve is not part of the Unit 2 containment boundary, this was considered a Unit I issue only. This valve is currently installed in Unit 1, location 1BS-0053, CNTMT PERS AIRLOCK 1-01 INT DOOR SWING DUAL FCV. On October 18, at approximately 1545, while Unit 1 was in mode 5 prior to startup from the 1 RF1 5 refueling outage, it was determined that the valve may not complete the 30 day mission time for containment isolation and the event was determined to be reportable per 50.72(b)(3)(ii)(B) as an unanalyzed condition that significantly degrades plant safety (NRC event 47352). At that time, Unit 1 was in Mode 5 and Operability of the Personnel airlock was not required. The airlock hydraulic system achieves containment integrity by being a closed system (If more space is required, use additional copies of (if more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
IV.
CAUSE OF THE EVENT
The personnel airlock valve and pressure gauges material was installed during original construction and discovered as a result of a licensee self-assessment. In 1990, it was discovered that the Unit 1 personnel airlock (PAL) was not being tested or operated in accordance with the design and technical specifications. The ASME isolation valves were being operated normally open instead of normally closed. The corrective action changed the design of the hydraulic system from Non-Nuclear Safety to ANSI Safety Class 2 and allowed the ASME isolation valves to remain normally open. Review of the design specification for the PAL indicates specific material requirements were not applied to components/subcomponents outside of the ASME boundary, such as is the case with 1 BS-0053. This condition was caused by a failure to properly assess the ANSI Safety Class 2 reclassification of aluminum containing components inside containment.
V.
CORRECTIVE ACTIONS
As a compensatory measure, the personnel airlock hydraulic system valve (1BS-0053) inside containment was encased in stainless steel to prevent exposure of the valve body to the sodium hydroxide in the containment spray. In accordance with the CPNPP Corrective Action Program, the airlock pressure gauges inside containment have been removed and replaced with a stainless steel plug to prevent a loss of the redundancy of the containment pressure boundary during and after a LOCA. Permanent corrective action will assure these parts are replaced with those made of suitable materials.
VI.
PREVIOUS SIMILAR EVENTS
There have been no previous similar reportable events at CPNPP in the last three years.PRINTED ON RECYCLED PAPER