ML073240390
| ML073240390 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 07/05/2007 |
| From: | Mary Johnson Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NL-07-2097, NMP-EN-002 | |
| Download: ML073240390 (7) | |
Text
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Southern Nuclear Operating Company SOUTHERNA Nuclear Actions for Potential Groundwater NMP-EN-002 Management Version 1.0 COMPANY Procedure Contamination Events PaQe 9 of 9 E-rr:1-Sn-w5.rWOr£i" 1
10 CFR 50.75(g) Leak/Spill Decommissioning Record PART 1 - Location/Source (R-type GG3.1 00)
Event Date Plant Name:
07 I 05 I 07 Vogtle Individual Contact Name:
Mike Johnson Check one: Leak?
x Spill?
Volume (gallons):
Location of spill/leak Source of spill/leak Gravel area at the southwest corner 88 of the Unit 1 Refuel Water Storage Rainwater from the Unit 1 (RWST) Moat Tank (RWST) Moat Duration of leak/spill: 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> Gamma Activity (uCi/cc)
Tritium Activity (pCi/L)
Total Area Impacted (ft2)
Water on Ground O/S Moat*
Gamma Spec # 07101972:
Cs 137: 4.185E-8 JiCilcc Moat Water - Gamma Spec
- 07101973: No Nuclides Found PART 2 - Event Description 33200 pCi/L 558 ft2 Outside of Protected Area?
D Yes
[I] No D Unknown If unknown, what actions needed to determine?
Description of eventlissue NlA On 07/05/2007 at 14:30, Health Physics personnel were notified that there was a potential leak at the Unit 1 RWST moat area.
An HP technician was dispatched to the area and found an area with standing water at the southwest comer of the U-1 RWST moat, running down to the U-1 Refueling Makeup Water Storage Tank (RMWST) building. The HP technician immediately reported the situation to the HP Foreman and HP Supervisor. Operations personnel were notified and dispatched to the area and began to investigate the source of the leakage. A leak at the base of the wall to the RWST valve gallery building was found and reported. HP personnel took water samples of the RWST moat and standing water from the ground outside of the moat.
Further investigation found that water from the moat was leaking into the valve gallery building through a degraded seal and from there the water was leakina from the building throuah another seal into the vard.
Actions Taken to Stop Spill or Leak HP took water samples and posted the area off as "Notify HP Prior To Entry". Operations personnel notified the Maintenance Department and a dirt benn was placed around the area to contain the leakage. In addition, personnel installed a berm inside the valve gallery to contain leakage from the moat and installed a pump to transfer water from the benn to a 55 gallon drum. The seal at the valve gallery wall was fortified and all leakage to the outside yard was stopped at 17:30. In addition, maintenance personnel attempted to channel the standing water to a low area and pump the water back into the moat, This met with minimal success, due to the shallowness of the water. Condition report # 2007107397 was written and assigned to the Maintenance Department to install new building seals.
Actions Taken to Clean-up Spill or Leak and Long Term Monitorina Based on the low activity found in the water samples, once the water has evaporated, the area will be de-posted. There is no planned excavation of the area at this time. This information will be included in the Vogtle Site Decommissioning Plan. Samples from the leak area showed up Cs-137 at levels comparable to ground samples from outside the leak area. The Cs-137 is believed to be attributable to weapons testina fallout, but not from the leak. The samples did not show UP anv other aamma
Southern Nuclear Operating Company SOUIHERNA Nuclear Actions for Potential Groundwater NMP-EN-002 Management Version 1.0 COMPANY Procedure Contamination Events Page 9 of 9
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emitters. The tritium levels from the leak area were the same as the tritium levels from inside the moat. No gamma emitters were found in the moat water. The tritium in the moat water was determined to be rainwater washout from the normal plant vent gaseous effluent for which environmental dose was already accounted for. Since the leaking water was found to be coming from the moat and the tritium in the water was due to rain washout, the moat leak will be repaired, but no other remedial action is planned for the soil.
PART 3 - Communications Condition Report Number:
2007107397 State Agency Notification:
(Describe what agency, N/A <<100 gallons not required) when and who)
NRC Notification (when and who)
N/A Figure 1
Gross Count Rate
=35.47 Background Count Rate
=11 LS-6500 Efficiency in %
= 33.18 Sample Volume in mls
=10 Sample Count Length in mins
= 30 Background Count Length in mins = 30 Dilution Factor
= 10
Discovered:
07/05/2007 3:00:00PM By:
Karim Yechou Phone:
4323 Dept:
Vogtle - Operations Sect:
OPS Shift 3 Building: Outside Areas Elev:
Room:
Location: UNIT 1 RWST Event:
Date:
Time:
Description of Condition:
Discovered water leaking from the RWST valve gallery and running on the ground in the Southwest area of the tank.
Upon further investigation we discovered water leaking into the RWST valve gallery from a piece of flashing with cracked caulking located on the south wall of valve gallery on the other side of the 1-1204-U4-207 valve.
Normal water level in the moat is approx. 5", but due to the Tritium concerns in the water collection areas the water level in the moat had increased above 4 feet.
What is affected:
Water leaking into unwanted areas I
How Discovered:
Area walkdown ICR Type Status Work Event:
1071158301 WalkThrough:
No Hold:
No OPS Review Req:
Yes Dispatch Comment:
Water is currently being contained by a makeshift berm and transferred into a 55 gallon drum and SUbsequently returned to the RWST moat. Estimate of water on the ground is approximately 60 gallons.
wbevans UserlD:
Equipment:
11204T4001 safety Class: S Nuc. Class: Ole Category:
Operability Status: Operable TSLCO#: 13.1.7 Active:
A Tag:
SIS REFUEUNG WATER STORAGE TANK,*,*,*
Type:
TNK Location:
Team:
Event:
1071158301 Tracking#:
N/A Type: T.R.M.
Reactor Building Unit 1 Comment: This is NOT borated water. Leakage source is RWST moat, NOT from the RWST. RWST remains intact. wbe 7/5/07 Event Related Evolutions In Progress:
None NRC Rpt.
Time:
Date:
Hours No ICompensatory Actions Taken' None IImm.
Received Date:
Short Explanation:
Severity Lev:
4 Reportable? D Impact to Plant:
7/6/07 12:43 pm Closed By:
Ihrichar BCD D ACD D RCCA DRCCA Resp. Dept:
Disposition Resp. Dept:
Vogtle - Maintenance Manager 7/6/07 12:43 pm 9/3/07 Ihrichar Due Date:
Reviewed By:
Approved By:
Explanation:
n/a TITLE TO PER DATE TYPE NUM PRB/PORC review? D Meeting Num:
Date:
IPRB/PORC Comments Major category: Equipment failure or malfunction (not Safety func. affected:
NA Cause Dept:
Event
Description:
Event Code Groupl:
Operational Related Events/Equipment Or Component Failure Or Damage/Other Event Code Group2:
Other Events/Others/Good Catch Award Event Code Group3:
Event Code Group4:
Department:
Vogtle - Maintenance Manager Section:
Person:
Status:
Final Review Required Prepared By:
Approved By:
Ihrichar Ihrichar Date:
7/6/07 Date:
7/6/07 Last Action Disposition:
Water is currently being contained by a makeshift berm and transferred into a 55 gallon drum and subsequently returned to the RWST moat.
Estimate of water on the ground is approximately 60 gallons.
Maint. rule scope? Yes Justification By: Igordon Function Failure?
No 7/19/07 Is this an MPFF?
No MR assigned to:
Leif Erik Gordon Justification:
The noted condition involves a significant amount of rain water collecting in the Unit 1 RWST moat and leaking into the RWST valve gallery area. The SIS (1204) functions as a source of borated water (RWST) to be used by ECCS and Containment Spray for RCS inventory makeup, reactivity control, containment pressure control and Spent Fuel Pool makeup. The water accumulating in the RWST moat does not hinder the SIS from performing the previously stated function. Therefore, the noted condition does not represent a functional failure as listed in the VEGP Scoping Manual for System 1204. - LEG 7/19/07 Status:
Event desc. or failure scenario:
Investigation scope/broadness review Is this a repeat event?
IRepeat event,"v;ew:
DOther train/channel/unit checked D
Pencil and Paper narrative D
Barrier analysis D
Change analysis D
Event and causal factor flow char.
IDescription of causes:
Cause Dept 1:
Cause Dept 2:
Cause Dept 3:
Groupl:
Group2:
Group3:
Group4:
Was Previous RCCA adequate?
DOther similar process checked Dcause identification DFault tree analysis D
Kepner-Tregoe Other:
[]other similar component I"lApparent cause L....lctetermination Sequence of event(s) documents attached Personnel statement(s) documents attached.
Event(s) review documents attached.
RCCA prepared by:
RCCA approved by:
RCCA final approver:
Documents: (DCMT)
Class Title MPS Documents:
Entity DocumentumlD Ver.
Ver Type Doc. Num.
Resolution work order Ixw:
TABl Title Minor MNT MPS Doc.ID.
1071158301 veRT
IWeb Documents:
Class Iproperty