ML101970280

Attachment 2, Complex Troubleshooting, MA-AA-716-004, Revision 9

ML101970280
Person / Time
Site:	Braidwood
Issue date:	06/16/2010
From:	- No Known Affiliation
To:	Office of Information Services
References
FOIA/PA-2010-0209, MA3862 MA-AA-716-004, Rev 9
Download: ML101970280 (13)

Text

- , MA-AA-716-004 Revision 9 Page 28 of 41 ATTACHMENT 2 Complex Troubleshooting (Troubleshooting Data Sheet)

Page 1 of 6 IR No: 1029126 Station: Braidwood WR No System:Aux Bldg - S1881 1valves WO No: Component/ETN: 1S18811A and 2SI8811AIB Operating Conditions: Full Power Initial Problem Statement: Tritiated water found under 2SI8811 B in Aux Bldg On 02/05/2010 Operating identified water on the floor under and around valve 2SI8811B. IR# 1026780 was written on 02/06/2010 identifying the issue. It was unknown where the water was originating from but from field inspections the water was not leaking from the overhead and no water was identified on the valve or piping components. There is a long standing issue with ground water originating from the penetration immediately adjacent to valve 2SI8811 B. A dam area was constructed under 2SI8811 B valve containment to channel the penetration ground water to a floor drain. A sample of the water was taken with a syringe by RP and was analyzed by Chemistry. The results of the sample indicate the following:

• Yellow in appearance (likely due to corrosion of penetration)

" Conductivity of 7340 uS/cm

" PH of 8.7

• Colbalt 58 present 7.2E-05 uCi/g

" Colbalt 60 present 4.5E-06 uCi/g

• Tritium present 4 million pCi/I

" Boron present 54 ppm On 2/11/10 IR# 1029126 was written to document that the following tritium concentrations have been measured in water that has collected due to rain water or ground water ingress near the SI 8811 valves in the outer curved room area.

0 6/24/09 Valve Enclosure Sample 1,500,000 pCi/L

• 11/01/09 Valve Enclosure Sample 824,000 pCi/L

• 2/5/10 penetration near 2Sl 8811 B 4,900,000 pCi/L

• 2/11/10 penetration near ISI 8811A 6,100,000 pCi/L 0 2/11/10 penetration near 2S1 881 1A 2,400,000 pCi/L There are several possible explanations for the high tritium concentration in this water. This could be contamination from spills, such as from the RWST, that can be spilled during refueling outages. Also this could be from tritium in the moisture in the room air that is transferred to any standing water. It could also be from unidentified leaks from water filled components or pools.

. k Li Engineering: .:CbrisBedford, Joshua Ducj El Corporate: PDominic Imburgia El Op's: iCraig Fobert Li Work Week Manager: NA Li Maintenance: NA LI Project Manager: N/A F1 Vendor: NA LI RPi Hieu Nguyen

'..i F*r Personnel Knowledgeable of the Problems:

NAME DEPARTMENT TELEPHONE NUMBER Raymond Hall, Morgan Davis - ENV 3203/3851 Chris Bedford SEB 2440 Terry Schuster, John Wilson, Chemistry 3200/3204/3201 Hasan Hannoun I is equipment Quarantine Req'd [ONO DIYES (if yes what equipment?)

Sequences of Events/Time Line: See initial problem statement above.

REQ'D Z YES (Attach) LR NO Critical Component Impacted LI YES [I NO Reviewed By; Raymond Hall Approved BylTerry Schuster. ,

If the comple oubleshootin.b*llan cannot be comited with hiqhffionfidence document decision to continue operations in Operational Technical Decision Making (OTDM) in accordance with OP-AA-106-101-1006 11 T-.hl k *; T 1 A JD 14 U 11 n-TfMRAW KIA I I U0JJIO1Uy1 "U 10011 U0 I yly VIIP11 Ill a. . LI rIf

MA-AA-716-004 Revision 9 Page 29 of 41 ATTACHMENT 2 Complex Troubleshooting (Troubleshooting Data Sheet)

Page 2 of 6 Document troubleshooting results identifying failed component and failure mode and the basis for high confidence (How physical evidence supports defined failed components and failure modes and refutes other potential failures.

Tritiated water under S 18811 valves Executive Summary -2/18/10 Initial Problem Statement: Tritiated water found under 2SI881 1B in Aux Bldg On 02/05/2010 Operating identified water on the floor under and around valve 2SI8811 B. IR# 1026780 was written on 02/06/2010 identifying the issue. It was unknown where the water was originating from, but from field inspections the water was not leaking from the overhead and no water was identified on the valve or piping components. There is a long standing issue with ground water originating from the penetration immediately adjacent to valve 2SI8811 B. A dam area was constructed under 2SI8811 B valve containment to channel the penetration ground water to a floor drain. A sample of the water was taken with a syringe by RP and was analyzed by Chemistry. The results of the sample indicate the following:

• Yellow in appearance (likely due to corrosion of penetration)

" Conductivity of 7340 uS/cm

• PH of 8.7

• Colbalt 58 present 7.2E-05 uCi/g

• Colbalt 60 present 4.5E-06 uCi/g

" Tritium present 4 million pCi/I

" Boron present 54 ppm On 2/11/10 IR# 1029126 was written to document that the following tritium concentrations have been measured in water that has collected due to rain water or ground water ingress near the SI 8811 valves in the outer curved room area.

• 6/24/09 Valve Enclosure Sample 1,500,000 pCi/L

• 11/01/09 Valve Enclosure Sample 824,000 pCi/L

• 2/5/10 penetration near 2SI 8811 B 4,900,000 pCi/L

• 2/11/10 penetration near 1SI 8811A 6,100,000 pCi/L

• 2/11/10 penetration near 2SI 8811 A 2,400,000 pCi/L There are several possible explanations for the high tritium concentration in this water. This could be contamination from spills, such as from the RWST that can be spilled during refueling outages. Also this could be from tritium in the moisture in the room air that is transferred to any standing water. It could also be from unidentified leaks from water filled components or pools.

A Complex Troubleshooting Team was assembled on 2/12/2010 that was led by Ray Hall (Environmental). Other members of the team included John Wilson (Chemistry), Morgan Davis (Environmental), Chris Bedford, Joshua Duc (Engineering), Craig Fobert (Operations), Hieu Nguyen (Radiation Protection) and Dominic Imburgia (Corporate Environmental).

The problem statement was that water contaminated with Tritium and Co-58/60 was found under 2SI8811 B in the Auxiliary Building curved wall area at 364' elevation. All actions in the troubleshooter address the water under all the S 18811 valves in both units and trains collectively. The following three potential causes were identified:

1. Water leaked from above 2SI881 B (from plant systems/roof)

2. Water from groundwater contaminated external to Auxiliary Building

3. Water from groundwater contaminated inside the Auxiliary Building To address the first potential cause that, the water was being leaked in from above the S18811 valves from pant systems or the roof, the following actions were identified. Operator inspections which included the ACM to check for water on the floor under the S18811 valves were reviewed. When operators noted that water was on the floor, there were no other signs of water in the area above the valves or on the valves. Water was identified as coming from the pipe penetration area. Additionally a review of historical IRs was conducted and discussed with an Engineering representative. The discussions with the engineer and the review of the historical IRs indicated that a long-standing issue with groundwater leaking in through the pipe penetrations near the S18811 valves has been previously documented. An action plan to address the in-leakage from these penetrations was already documented in CAP with WR created. WR are still open pending scheduling and completion. The IRs also identified previous roof leakage around these areas. The roof was repair recently and no leaks have been identified in the roof since the repairs were completed. In conclusion there was no evidence that supported that the cause of the water on the floor under the S18811 valves was from water leaks from above.

The second potential cause was that, the water under the S18811 valves was groundwater that was contaminated external to the Auxiliary Building and leaking in through the pipe penetrations to the floor. If the contaminated groundwater was leaking in through the pipe penetrations the contamination would indicate that a leak existed in a nearby highly tritiated system. Potential systems identified included Spent Fuel Pool, RWST, CWBD, and PWSTs.

The potential for the groundwater being contaminated from the SFP was investigated by the System Engineer walking down the system and visually observing the tell tails for signs of leakage. No leakage was identified. Operator rounds were reviewed to see if any signs of leakage or abnormal conditions were observed and documented. There were no documented abnormal conditions or signs of leakage. Review of SPF make-up trends and sump run time trends were reviewed to validate that no gross leakage existed. No adverse trends were identified. Sample results from the floor samples taken on 2/5/10 and 2/11/10 along with the sample results from the penetration sample taken on 2/16/10 were compared with the SFP characteristics. Key parameters included Tritium, boron and PH.

System Boron(ppm) Conducitivy(us/cm) Tritium pCi/I PH SFP 2496 NA 386,000,000 4.67 Boron concentrations were 54ppm from the floor sample and <1 ppm from the penetration. Much higher boron concentrations would be expected to be found if the groundwater was contaminated from the SPF. Tritium concentrations from the floor samples and the penetration were in the range of 2.4million to 6.1million pCi/I. Much higher tritium concentrations would be expected to be found if the groundwater was contaminated from the SPF but could be lower based on dilution. PH from the floor samples and the penetration were in the range of 8.7 to 10.2. A much lower pH would be expected to be found if the groundwater was contaminated from the SPF, although the elevated pH could be attributed to the contact with the concrete as it is leached through the penetrations. All results obtained from actions taken to identify leakage from the SFP indicate that no leakage is occurring and that the analytical results do not indicate that the contamination is from the SPF.

The potential for the groundwater being contaminated from the RWSTs was investigated by reviewing operator rounds to see if there were any signs of leakage observed and documented. No signs of leakage were documented. Review of RWST makeup trends did not show adverse trends. These trends would only validate gross leakage. Sample results from the floor samples taken on 2/5/10 and 2/11/10 along with the sample results from the penetration sample taken on 2/16/10 were compared with the SFP characteristics. Key parameters included Tritium, boron and PH.

System Boron(ppm) Conducitivy(us/cm) Tritium pCi/I PH RWST 2379 NA 420,000,00 4.42 Boron concentrations were 54ppm from the floor sample and <1 ppm from the penetration. Much higher boron concentrations would be expected to be found if the groundwater was contaminated from the RWSTs. Tritium concentrations from the floor samples and the penetration were in the range of 2.4million to 6.1 million pCi/l. Much higher tritium concentrations would be expected to be found if the groundwater was contaminated from the RWSTs but could be lower based on dilution. PH from the floor samples and the penetration were in the range of 8.7 to 10.2. A much lower pH would be expected to be found if the groundwater was contaminated from the RWSTs, although the elevated pH could be attributed to the contact with the concrete as it is leached through the penetrations. All results obtained from actions taken to identify leakage from the RWSTs indicate that no leakage is occurring and that the analytical results do not indicate that the contamination is from the RWSTs.

The potential for the groundwater being contaminated from the PWSTs was considered but was not investigated due to the location of the tanks. A leak from the PWST tanks would not likely flow to this area without first being identified in other areas.

The potential for the groundwater being contaminated from the CWBD line was considered but was not specifically investigated due to the location of the line. Other sample results that will be discussed later indicate that the contamination is from the CWBD line.

The potential for the groundwater being contaminated from the Spent Fuel Pool, RWST, CWBD, and PWSTs was also investigated collectively. If the contaminated groundwater was from a nearby highly tritiated system leaking in through the pipe penetrations the contamination would be expected to be found in other groundwater located in this area. Groundwater inleakage was sampled in the 1B/C MSIV and 2 B/C MSIV Rooms at the 377' elevation. This water should be representative of me groundwater in this area excluding any internal contamination in these rooms. The results of these samples that were taken on 2/12/10 showed tritium concentrations in the range ofU68to 7393 pCi/I nd no Co- 58/60 activity. Much higher tritium concentrations would be expected to be found if the groundwater was contaminated from one of the highly tritiated sources listed above. Also MW-BW-201 I, MW-BW-2021 and MW-BW-2031 groundwater monitoring wells were sampled on 2/13/10 for tritium. These monitoring wells would be representative of groundwater that has migrated from the area of concern as these wells are located to the north and east of the area. The primary groundwater flow on the site is to the north-northeast.

The wells are sample semiannually per the RGPP and historically tritium concentrations have been < 200 pCI/I. The sample results from the 2/13/10 sampling indicate that the tritium concentrations in all three wells were < 171 pCi/I. Sampling the groundwater in the tendon tunnel was also considered but was determined as not needed based on the results of the samples listed above and the potential for internal contamination. Collectively these results indicate that the groundwater has not been contaminated in this area.

The third potential cause was that the water under the S18811 valves was groundwater is leaking in through the pipe penetrations to the floor and was contaminated internally to the Auxiliary Building. Four methods were used to determine if uncontaminated water could be contaminated by being exposed to the environmental conditions inside the Auxiliary Building.

The first method used to investigate contamination internal to the CWA of the Auxiliary Building was to take smear samples of the floor in the area of the S18811 valves. The smear sample indicated that the floor is contaminated with Co-58/60 likely due to previous historical spills in this area.

The second method used was to place a 24" berm on the floor in the curved wall area in both the Ul and U2 sides near the S18811 valves on the 364' elevation. Two liters of DI water was placed in each berm and then sampled at approximately 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> intervals for tritium. Results from the U1 berm samples showed concentrations of tritium of 840,000 pCi/I after 4.75 hrs of soak time and a maximum of 4.2million pCi/I after 11.75 hrs. No additional samples could be taken after the last sample due to no sample volume being available due water removed during previous sampling and evaporation. The U2 berm was sampled after 2.5 hrs of soak time and yielded a tritium concentration of 391,009 pCi/I. The U2 berm could only be sampled one time due to no additional sample volume being available due to possible leakage and evaporation. The results of this test indicate that it is possible to contaminate clean water to very high levels of tritium concentration as found in the water samples collected under the S18811 valves by just being exposed to the floor surface and air in the CWA of the Auxiliary Building.

The third method used to determine if clean water could be contaminated by the Auxiliary Building environment in the CWAX was to place a bucket in the U1 and U2 areas near the S18811 valves. Four liters of DI water was added to the buckets and then sampled approximately 8 hrs after the water was added and then at 4 hr interval after the first sample. The UI bucket sample after 8 hrs yielded a tritium concentration of 286,050 pCi/I with a maximum value of 4.9million pCi/I after 20hrs. The U2 bucket sample after 9 hrs yielded a tritium concentration of 48,385 pCi/I with a maximum value of 167,068 pCi/I after 28hrs.

Although the same maximum values were not achieved in both units, this test does indicate that it is possible to contaminate clean water with tritium by being exposed to the atmosphere in the CWA of the Auxiliary Building.

The fourth method used to determine if clean water could be contaminated by the Auxiliary Building environment in the CWA was to place a dehumidifier in the U1 and U2 areas near the S18811 valves. The dehumidifiers were placed in area of the S1881 1 valves and ran for 5 days and still did not yield any volume of liquid to sample. This test yielded no results.

In summary, based on the investigation documented above, there is no indication that the groundwater leaking into the Auxiliary Building through the penetrations on the 364' elevation in CWA near the S18811 valves is externally contaminated.

The groundwater that is on the floor under the S18811 valves appears to be leaking through the pipe penetrations and is being contaminated by the internal environment in the CWA of the Auxiliary Building.

Troubleshooting Team Lead ymond Ha Date: 2/18/10

MA-AA-716-004 Revision 9 Page 30 of 41 ATTACHMENT 2 Complex Troubleshooting (Troubleshooting Data Sheet)

Pacae 3 of 6 Data Gathering Checklist (Check box for data attached)

Internal Sources:

Documentation Recorded Data ED Interviews E Operating Logs E] Correspondence El Maintenance Work Packages and Records El Internal Sources 0 Inspection Records E] Industry Bulletins El Equipment History Records El EPIX Records El Strip Chart Recordings E OPEX Records El Trend Chart Recordings 0 Procedures and Instructions El Sequence of Event Recorders El Vendor Manuals El Radiological Surveys Z Drawings and Specifications El Plant Parameter Readings Z Sample Analysis and Results El Post Maintenance/Mod Test Results El Design Basis Information 0 Previous CRs External Sources:

El Written Statements El Correspondence

[E PRA El Industry Bulletins E] Part 21 Records El Vendor Contacts IE Recent Mods to SSC El NRC NRR Suggested Topics/Questions to Support Failure Modes Analyses El What is the purpose/function of the El When did the failure(s) occur? How do you know for system/component? sure?

How is the system/component designed to El Could the unwanted energy (e.g., motive power, work? control power, instrument air, hydraulic fluid, etc.)

have been deflected or evaded?

El How does the system/component really work? El Have all reasonable failure modes been identified?

El What components are potentially involved? El Were adequate human factors considered in the design of the equipment?

How is the system/component supposed to El Have similar failures occurred before at Exelon be operated? stations or the indus try?

How is the system/component really El Is the system/component properly labeled for ease of operated? operation?

El Are vendor operation and maintenance El How was the failed component maintained?

recommendations followed?

El Is there sufficient technical information for El What is the maintenance history for the operating the component properly? system/component?

El What is the operating history for the El Is there sufficient technical information for maintaining system/component? the component properly?

El What form of energy (e.g., motive power, El Did the environment (e.g., humidity, vibration, etc.)

control, power, instrument air, hydraulic fluid, have an effect on the problem?

etc.) caused the first component/subcomponent to fail?

El What form of energy (e.g., motive power, El Could the commercial grade dedication process have control power, instrument air, hydraulic fluid, contributed to the failure(s)?

etc.) caused the second, third, etc.,

component/subcomponent to fail?

El Was this energy (e.g., motive power, control El Could this failure affect the opposite train/unit? If not, power, instrument air, hydraulic fluid, etc.) why?

supposed to be present or was it undesirable?

El What failed first? El Is this failure also on the opposite train/unit? What is the difference? Why is it different?

El Could something have failed earlier than the time of the event?

El Did any thing else fail as a result of the first failure?

El What barriers existed between the energy (e.g., motive power, control power, instrument air. hvdraulic fluid. etc.) and the first failure?

N

ATTACHMENT 2(Failure Mode Tree)

Page 4 of 6 PROBLEM Water contaminated with Tritium and Co-60 found under 2SI881 I B in Aux Building CAUSE I CAUSE 2 CAUSE 3 Water leaked from Water from Water from above 2S1881 IB groundwater groundwater (from plant contaminated contaminated inside the Aux systems/roof) external to Aux Bldg Bldg.

1) Observe area to 1) Sample groundwater 1) Floor or air contaminated in the aux determine origin of in MSIV room. - building.

water. - No water Sample results were a. Pool created in CWA ofdeionized water.

observed from 7400 pCi/L No Co- Measure tritium over time. - Three above. 58/60. measurements yield increasing tritium

2) Long standing issue 2) Sample nearby for U I D1 berm . Only one measurement with groundwater. ground water on U2 Dl berm due to no additional All water contained monitoring wells for sample available. No unusual isotopes within bermed area. tritium. Co-58/60 were found during analysis.

Confirmed with will not be sampled b. Smear floors - Smears show floor is Engineering and because it's affinity contaminated with Co-58/60 historical IRs. to be absorbed in c. Contamination from floor soil. d. Contamination from air - U I and U2

3) Sample tendon dionized water buckets show increasing tunnel- Not trend with tritium concentration.

completed due to other sample results and potential internal contamination.

4) Check leakage from

a. Fuel pool

b. RWST

c. CWBD

d. PWST ATTACHMENT 2 Complex Troubleshooting (Failure Mode / Cause Table)

Page 5 of 6 Failure Mode No. 1

Description:

Water leaked from above the 2SI881 I B (from plant systemlroof)

Refer to Attachment 4 Results Owner for examples of risk *Expected results are based on system operation Status and rigor determination as designed, not as failed for steps below

Cause(s) Validation/Action Steps Expected Actual Observe Observe area to No visual water No visual water Operations -

area to determine origin of water. source observed observed ACM Rounds determine Operator inspections from overhead overhead. Data Review origin of (ACM round data) did not Visual water COMPLETE water. identify any process source seen water sources over head from well or in the area. Water penetration.

was identified from the wall penetration.

-~

Riaor

~

D J .1-Long Review historical IRs and Corrective actions NA standing discuss issue with for the groundwater issue with Engineering to determine intrusion in this ground that ground water has area have not been water. All been previously identified implemented.

water in this area.

contained Roof was repaired within berm. and is not leaking.

NA Roof was repaired recently and roof leakage was resolved.

_________________ L Riaor D

--- ~----- I _________________________ L_____________________ L

Failure Mode No. 2

Description:

Water from groundwater contaminated external to aux building.

Refer to Attachment 4 Results Owner

• Expected results are based on system operation for examples of risk Status as designed, not as failed and rigor determination for steps below I t Cause(s) Validation/Action Steps Expected Actual Groundwater Low levels for both Tritium levels: Ray Hall --

contaminated Sample groundwater in 2 tritium and no 2 B/C MSIV- "ChemistrT-B/C MSIV and 1 B/C levels of Co-58/60 COMPLETE form highly 7393 pCi/L contaminated MSIV rooms for tritium 1 B/C MSIV-tritium source and Co-58/60 3668 pCi/L (Fuel Pool, contamination. This RWST water should be Co-58/60 Ray Hall-CWBDT representative for Analysis - No 'hemistry -

PWST) groundwater in area Co-58/60 COMPLETE except for internal identified contamination.

Riaor D 4 4 Groundwater Low levels for both Tritium levels: Ray Hall-,j contaminated Sample groundwater tritium All well samples Chemistrv form highly monitoring wells in the <171 pCi/L COMPLETE contaminated vicinity and down tritium source gradient of potential (Fuel Pool, contamination sources RWST for tritium. Co-58/60 was CWBD, not sampled due to these PWST) isotopes having an affinity for soil.

I Riaor D

- -~ I Groundwater Low levels for both N/A ,*Ray Hall-contaminated Sample ground water in tritium and no The tearrr form highly tendon tunnel for tritium levels of Co-58/60 Determined that contaminated and Co-58/60 this sample was tritium source contamination. This not needed (Fuel Pool, water should be based on RWST) representative for previous results CWBD. groundwater in area and potential PWST) except for internal internal contamination. contamination Rieor D I .1 J

Groundwater No leakage No leakage contaminated Visual observation of tell identified during identified during form Fuel tails to identify any observation of tell observation of Pool. leakage. tails. tell tails.

No leakage No leakage Review ODS round to see identified during the identified during if there are any signs of review of ops round the review of leakage observed and data for fuel pool. ops round data documented. for fuel pool.

No adverse trends identified. No adverse trends identified.

Review spent fuel pool make-up trends and sump run time trends.

This parameter is only valid for gross leakage.

_________________ L Riaor D

-~-.~-=---=- J. -~

Groundwater No visual leakage No visual contaminated Review ops round to see documented leakage form RWST if there are any signs of documented leakage observed and No change in documented. RWST make up No change in rates. RWST make up Review RWST make up rates.

trends. This parameter is only valid for gross leakage.

Riqor D Groundwater N/A contaminated This cause was ruled out form PWST due to location of tank., A PWST leak would not likely flow to this area.

Groundwater Low levels for both I rltium levels:

contaminated Sample groundwater in 2 tritium and no 2 B/C MSIV -

form CWBD B/C MSIV and 1 B/C levels of Co-58/60 7393 pCi/L MSIV rooms for tritium 1 B/C MSIV-and Co-58/60 3668 pCi/L contamination. This water should be Co-58/60 representative for Analysis - No groundwater in area Co-58/60 COMPLETE except for internal identified contamination.

Riaor D

Failure Mode No. 3 Water from the groundwater contaminated inside the Aux Building.

Refer to Attachment 4 Results Owner for examples of risk *Expected results are based on system operation Status and rigor determination as designed, not as failed for steps below Cause(s) Validation/Action Steps Expected Actual Contaminatio Lower levels of U1 and U2 DI -,Ray Hall --F n source is Air and Floor - Create a tritium expected. berm sample Chemistry from aux pool in the CWA of results show a COMPLETE building. deionized water for U1 increasing trend and U2. Measure tritium in tritium concentration over time. concentration over time.

Floor is Floor is n ýlieu

, Nguyen contaminated due contaminated P Floors Smear floors in Flos- SerfosinCo-60 to historic. spills in with Co-58 and COMPLETE the area. the aux building.

TBD,,. U1 and U2 DI bucket sample rPieu Nguyen C-OP results show a Air - Staqe buckets with increasing trend COMPLETE DI water in the vicinity tritium - RaCHalle t in- Chemistr and measure tritium concentration COMPLETE concentration over time. over time.

/

TBD No sample __-ieu Nguyen -

volume was obtained from COMPLETE obtaindiferom Oay Hall--"

dehumidifers. -Chemistry Air - Stage de- COMPLETE humidifiers in the vicinity and measure tritium concentration over time.