05000280/LER-1998-010, :on 980715,low Intake Canal Level Instrument Channel I Was Declared Inoperable to Allow Testing of Intake Canal Level Probe 1-CW-LE-102.Subject Probe Was Cleaned by Diver,Tested & Channel I Was Returned to Operable Status
| ML18152B781 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/31/1998 |
| From: | Grecheck E VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | |
| Shared Package | |
| ML18152B780 | List: |
| References | |
| LER-98-010, LER-98-10, NUDOCS 9808070008 | |
| Download: ML18152B781 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2801998010R00 - NRC Website | |
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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB NO. 3150-0104 (4-95)
EXPIRES 4/30/98 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 50.0 HRS.
LICENSEE EVENT REPORT (LER)
REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (T*6 F33).
(See reverse for required number of digits/characters for each block)
U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC 20555-0001. AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104).
OFFICE OF MANAGEMENT AND BUDGET.
WASHINGTON. DC 20503.
FACILITY NAME (1)
DOCKET NUMBER (2)
PAGE (3)
SURRY POWER STATION, Unit 1 05000 - 280 1 OF 5 TITLE (4)
Intake Canal Level Probes Inoperable Due to Marine Growth EVENT DATE (5)
LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8)
MONTH DAY YEAR YEAR I SEQUENTIAL I REVISION MONTH YEAR FACILITY NAME DOCUMENT NUMBER DAY Surry Unit 2 NUMBER NUMBER 05000-281 07 15 1998 1998
-- 0 IO --
00 07 31 1998 FACILITY NAME DOCUMENT NUMBER 05000-RATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more) (11)
DE (9)
N 20.2201(b) 20.2203(a)(2}(v)
X
- 50. 73(a)(2)(i) 50.73(a)(2)(viii) 20.2203(a)(1) 20.2203(a)(3)(i) 50.73(a)(2)(ii)
- 50. 73(a)(2)(x)
)
1 20.2203(a)(2)(i) 20.2203(a)(3}(ii)
- 50. 73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50.73(a)(2)(iv)
OTHER 20.2203(a)(2)(iii)
- 50. 36( c)( 1)
- 50. 73(a)(2)(v)
Specify in Abstract below 20.2203(a)(2)(iv) 50.36(c)(2)
X 50.73(a)(2)(vii) or in NRG Form 366A LICENSEE CONTACT FOR THIS LER 12 NAME I
~;;;;N;;;:;~~~de Area Code)
E. S. Grecheck, Site Vice President COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS TO NPRDS SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED MONTH DAY YEAR X I YES I I NO SUBMISSION
. 10 30 1998 (If yes, complete EXPECTED SUBMISSION DATE).
DATE
~BSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)
On July 15, 1998, with Units 1 and 2 operating at 100% power,. low intake canal level instrument Channel I was declared inoperable at 10:27 to allow testing of intake canal level probe 1-CW-LE-102. The as-found response time of 1-CW-LE-102 was unsatisfactory. Similar*
marine fouling had been observed the previous day on intake canal level probe 2-CW-LE-203.
Recognizing that biofouling represents a potential common failure mechanism, 2-CW-LE-203 and the associated low intake canal level instrument Channel IV were conservatively declared inoperable at 10:50. With Channels I and IV both inoperable, an action *statement was entered in accordance with Technical Specification (TS) 3.0.1. 1-CW-LE-102 was cleaned by a diver, tested satisfactorily, and Channel I was returned to operable status.
The TS 3.0.1 action statement was exited at 11 :28. 2-CW-LE-203 was tested at 14:23. The as-found response time was unsatisfactory. 2-:CW-LE-203 was cleaned by a diver, tested satisfactorily, and Channel IV was returned to operable status at 16:38. The condition of the other two intake c_anal level probes was evaluated and determined to be acceptable. A Root Cause Evaluation is being performed to determine the causes of this event and to recommend corrective actions. This report is being submitted pursuant to 1 O CFR 50.73(a)(2)(i)(B) and 1 O CFR 50. 73(a)(2)(vii)(D).
9808070008 980731 PDR ADOCK 05000280 S
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.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
DOCKET LER NUMBER (6)
PAGE (3)
YEAR I SEQUENTIAL l REVISION NUMBER NUMBER Surry Power Station Unit 1 05000 - 280 1998
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00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) 1.0 DESCRIPTION OF THE EVENT On July 15, 1998, with Units 1 and 2 operating at 100% power, low intake canal level instrument Channel I [EIIS-JE,CHA] was declared inoperable. at 10:27 to allow testing of intake canal level probe 1-CW-LE-102 [EIIS-'KE,LE]. In accordance with Technical Specification (TS) Table 3.7-2, Operator Action No. 20 was entered requiring Channel I to be returned to service or placed in trip within six hours. The scheduled periodic test was performed in accordance with 1-IPT-CC-~W-L-102, "Intake Canal Level Probe 1-CW-LS-102 Time Response Test and Channel.Calibration." The results of the test were unsatisfactory with the as-found response time of 1-CW-LE-102 exceeding the
.acceptance limit (60 seconds).
Although to a lesser extent, similar marine fouling had been observed the previous day on intake canal level probe 2-CW-LE-203. Recognizing that biofouling represents a potential common failure mechanism, 2-CW-LE-203 and the associated low intake canal level instrument Channel IV were conservatively declared inoperable at 10:50. In accordance with TS Table 3.7-2, Operator Action No. 20 was entered for Channel IV.
With Channels I and IV both inoperable, an action statement was entered in accordance with TS 3.0.1, requiring both units to be placed in Hot Shutdown (HSD) within six hours.
1-CW-LE-102 was inspected and cleaned by a diver, who removed some marine 2 OF 5 growth. The probe was subsequently tested satisfactorily and Channel I was returned to operable status. The TS 3.0.1 action statement and the TS 3.7-2 action statement for Channel I were exited at 11 :28.
2-CW-LE-203 was tested in accordance with 2-IPT-CC-CW-L-203 at 14:23. The results of the test were unsatisfactory with the as-found response time exceeding the acceptance limit. 2-CW-LE-203 was inspected and cleaned by a diver and subsequently tested satisfactorily. While the condition of 2-CW-LE-203. was further evaluated by Engineering, Channel IV was placed in the tripped condition at 15:00 and the associated TS 3.7-2 action statement was exited.
Engineering later concluded that the condition of 2-CW-LE':'203 was acceptable. At 15:27, Channel IV was restored and TS Table 3.7-2, Operator Action No. 20 was entered to facilitate additional testing of 2-CW-LE-203. The probe was tested satisfactorily and Channel IV was returned to operable status. The TS 3. 7-2 action statement for Channel IV was exited at 16:38.
The condition of the other two intake canal level probes, 1-CW-LE-103 and 2-CW-LE-202, was evaluated. The evaluation concluded that 2-CW-LE-202 did not need to be tested since it had been cleaned and tested satisfactorily on July 11, 1998.
The condition of 1-CW-LE-103 was also determined to be acceptable based on a visual
- inspection performed on July 14,* 1998.
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.. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
Surry Power Station Unit 1 DOCKET LER NUMBER (6)
PAGE (3) 05000 - 280 TEXT (If more space is required, use additional copies of NRG Form 366A) (17) 1.0 DESCRIPTION OF THE EVENT (Continued)
YEAR I SEQUENTIAL l REVISION NUMBER NUMBER 1998
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00 The NRC was notified pursuant to 10 CFR 50.72(b)(2)(iii)(D) on July 15, 1998, at 17:21.
This report is being submitted pursuant to 1 O CFR 50.73(a)(2)(i)(B) because the inoperable canal level probes represent a condition prohibited by TS 3.7. This report is also being submitted pursuant to 10 CFR 50. 73(a)(2)(vii)(D) since a single cause resulted in two independent channels becoming inoperable in a single system designed to mitigate the consequences of an accident.
2.0
SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
The non-essential service water (SW) automatic isolation function [EIIS-JE,KG] ensures adequate intake canal inventory can be maintained by the emergency service water pumps [EIIS-Bl,P] following a design basis loss of coolant accident (LOCA) with a coincident loss of offsite power (LOOP). This function is designed to actuate when any three of the four intake canal level probes senses a canal level that is less than 23.5 feet.
To determine the potential impact of this event on the non-essential SW automatic isolation function, Engineering analyzed the results of the canal level probe testing. The analysis concluded that the as""'.found response time for the two degraded probes, although delayed, would have been sufficient to support the design basis canal inventory requirements.
The intake canal level is also monitored by an independent system that provides level indication and high/low level alarms in the main control room. In the event of a low.
canal level condition, station procedures direct corrective/mitigative actions, including isolation of non-essential SW.
During this event, a LOCA/LOOP did not occur and the intake canal level remained above 23.5 feet. In summary, this event resulted in no safety consequences or significant implications and the health and safety of the public were not affected at any time.
3.0
CAUSE
A Category 1 Root Cause Evaluation (RCE) is being performed to determine the causes of this event and to recommend corrective actions. Following the completion of the RCE, a* supplement to this Licensee Event Report will be submitted which will discuss the causes of this event. 3 OF 5
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.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1)
Surry Power Station Unit 1 DOCKET LER NUMBER (6)
PAGE (3)
YEAR I SEQUENTIAL I REVISION NUMBER NUMBER 05000 - 280 1998
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00 TEXT (If more space is required, use additional copies. of NRG Form 366A) (17) 4.0 IMMEDIATE CORRECTIVE ACTION(S)
Following the unsatisfactory testing of 1-CW-LE-102 on July 15, 1998, 2-CW-LE-203 and the associated low intake canal level instrument Channel IV were conservatively declared inoperable. With Channels I and IV inoperable, an action statement was entered at 10:50 in accordance with TS 3.0.1.
1-CW-LE-102 was inspected and cleaned by a diver and was subsequently tested satisfactorily~ Channel I was returned to operable status and the TS 3.0.1 action statement was exited at 11 :28.
2-CW-LE-203 was tested at 14:23. The results of the test were unsatisfactory with the as-found response time exceeding the acceptance limit. 2-CW-LE-203 was inspected and cleaned by a diver and subsequently tested satisfactorily. Channel IV was returned to operable status at 16:38.
A Deviation Report was submitted to document the deviating condition and to initiate
corrective actions
The condition of the other two intake canal level probes, 1-CW-LE-103 and 2-CW-LE-202, was evaluated. The evaluation concluded that the condition of these two probes was acceptable.
5.0
ADDITIONAL CORRECTIVE ACTIONS
The operability of 1-CW-LE-103 was confirmed by testing on July 15, 1998, at.17:48.
An interdepartmental RCE Team investigation was initiated by station management to determine the causes of this event.
6.0 ACTIONS TO PREVENT RECURRENCE The condition of the intake canal level probes is being monitored more closely as the RCE is being conducted. Following the completion of the RCE, a supplement to this Licensee Event Report will be submitted which will discuss the actions to prevent the recurrence of a similar event. 40F5
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.S. NUCLEAR REGULATORY COMMISSION
. FACILITY NAME (1)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION DOCKET Surry Power Station Unit *1 05000 - 280 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) 7.0
SIMILAR EVENTS
YEAR 1998 LER NUMBER (6)
I SEQUENTIAL I REVISION NUMBER NUMBER
--010--
00 LER 50-280/50-281/97-:-009..:oo, "Intake Canal Level Probes Inoperable Due to Marine Growth" LER 50-280/50-281/95-006-00, "Emergency Service Water Pumps 1-SW-P-1A and 1~SW-P-1C Inoperable Due to Marine Growth"
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